The Growth and Production of Crude Oil from Algae Using Hydrothermal Liquefaction and Catalytic Hydrothermal Liquefaction
Item Type text; Electronic Thesis
Authors Cordon, Michael; Zuun, LI; List, Tyler; Zhang, Aaron
Publisher The University of Arizona.
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Download date 28/09/2021 01:29:12
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Link to Item http://hdl.handle.net/10150/297546
Abstract: This report evaluates the current economic outlook of producing algal biofuels as a potential replacement for fossil fuels. The proposed design incorporates two new technologies: hydrothermal liquefaction and catalytic hydrothermal gasification. Both of these technologies provide significant advantages over other dewatering, extraction, and residual biomass processing methods that are typically considered in past models. The design also accounts for the maximal recycle of resources in the system including water, nutrients, carbon dioxide, and heat. Based on current market info, it was shown that the design is not economically feasible at this time. The plant would break even (NPV of $0 at a 40% tax rate) after 30 years if the selling price of the oil is $174 per barrel. A Monte Carlo simulation was established to monitor the effects that different operating conditions have on the commercial viability of the process. In approximately 5% of the scenarios, a positive economic outlook was found for the proposed plant. These parameters include the efficiency of the electric generator, the price of the oil, the price of electricity, the yield out of hydrothermal liquefaction, and the yield of algal biomass out of the growth raceways.
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Executive Summary:
The main goal of this design is to produce 0.1% of Florida’s daily oil use in a sustainable way. The design utilizes algae to produce fatty acids that can be converted into heavy crude sweet oil downstream. The process utilizes two newer technologies for processing algae in order to analyze their potential impacts and improvements on the algae biofuel production process. These two processes are hydrothermal liquefaction (HTLE) and catalytic hydrothermal gasification (CHG). HTLE is used to convert residual biomass into oil derivatives such as fatty acids to increase the product yield from the algae. CHG converts the remaining residual biomass into a combination of methane and carbon dioxide to eliminate the solid waste from the system. This methane can also be burned to produce heat for use in the plant and to generate electricity in a power generator. The design is broken down into four major areas that work in tandem to produce the oil. The first section is the algae growth which occurs in large raceway systems. The growth setup utilizes carbon dioxide from a source of flue gas and a recycle stream for media recovery and reuse as a means of providing the algae with the appropriate nutrients to facilitate rapid growth and fatty acid production. The output from these raceway systems is fed into the second section of the process which is the cold operations section. In this part of the plant, a filter system is utilized to make the algae more concentrated in the liquid stream by filtering out large portions of the unneeded growth media. This is performed using a filtration process similar to that of reverse osmosis. The cold operations also handle the recycle of water from throughout the plant in a mixer. This mixer is used to generate new media to feed back into the growth section. A generator is also located in this section to convert excess heat from other parts of the plant to generate electricity. These two recycle systems make the plant highly sustainable and independent of the market. The third stage of the plant is the hot operations section. This section sees the use of both HTLE and CHG to process the algal biomass. The major pieces of equipment include multiple heat exchangers, reactors, and tanks to perform separations in the working fluids. The working conditions in this part of the plant are typically at least 150 bar and 300°C. A combustion reactor is also placed here to combust methane and convert it into a renewable source of electricity. The last section of the plant deals with the downstream processing of the separated crude oil. Since the algal biofuel has a high concentration of nitrogen and oxygen, the fluid is fed through a reactor that performs both denitrification and deoxygenation. This
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effectively cleans the oil and turns it into a higher quality product, allowing it to be sold for a higher price. Generally speaking, the safety and environmental concerns of the plant are minimal. The chemicals in the growth media have essentially no harmful effects, especially when dissolved in water. The catalysts provide a larger threat to the health of the operators and the surrounding environment yet they are exclusively located inside of the reactors under high pressures and temperatures. Therefore, there is little chance for contact between the catalysts and the outside world. From an environmental standpoint, the plant is essentially carbon neutral since it takes in carbon dioxide from flue gas to grow the algae. The water requirements are negligible compared to the other flow rates throughout the system and the plant actually makes enough electricity to sell back to the grid. This makes the plant highly sustainable and independent. The project lifetime chosen for the process is thirty years. With a 40% tax rate and normal and current values for all utilities and sale prices, an NPV of -$98.9 million was found. The sale price to get the NPV to a value of zero was found to be $174. The main cost of the process which led to the highly negative NPV is the bare module cost of the equipment. A Monte Carlo simulation was done as a complementary economic analysis to test the sensitivity of key variables in the process. The variables deemed most likely to change throughout the lifetime of the plant are oil price, electricity price, HTLE yield, algae growth yield, and generator efficiency. 9943 trials were run to reduce the sampling error and an average NPV of -$45.8 million was found. The NPV was found to be between -$100.1 million and $9.6 million for 95% of the trials. Approximately 5% of the trials yielded a positive NPV after thirty years. The most apparent economic hazard of the process is the volatility in the markets. The oil market is a highly specific, rapidly changing world market that is too complex for any one person to speculate on. It is therefore likely that any projections on oil price will be unreliable in a thirty year window.
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Group Roles and Responsibilities: This project was designed based off of contributions from four different team members. The primary work was divided into several different sections with each member offering several contributions to the final objective. Michael made several major contributions to the project overall. First off, he developed the models for the growth calculations and the design of the raceway systems. He also built the model for the CHG process and for the upstream processing stages of the plant. This includes the filtration system, the precipitation tank and sulfur scrubber combination, the heat exchangers and pumps, and the water recycle system. In addition to this, he created the process flow diagrams and the block flow diagram. From these diagrams, he wrote the process description, rationale, and optimization, the equipment description, rationale, and optimization, and the introduction. He also wrote several of the appendices for the final submission. For the team experience, Michael organized many of the meetings by leading the conversations through the required topics as well as taking meeting minutes to keep everyone on track. He also organized the compilation of the final report and kept the team on track for completion. He also edited all other portions of the report that were submitted and helped to answer questions from all other teammates. Tyler helped the team by keeping track of the master spreadsheet. He designed the HTLE and downstream processing sections of the plant by scaling up the two processes accordingly. The downstream processing included the denitrification and deoxygenation section and the surrounding heat exchangers and pressure equipment. By maintaining the master spreadsheet, Tyler made sure that each of the models for the various sections of the design were conglomerated together properly. This allowed for one change in the spreadsheet to affect everything else properly. Tyler also wrote several sections of the report itself. He developed the Monte Carlo simulation code and wrote the corresponding section to go with it. He also wrote the recommendations and conclusions sections and the calculations appendix to go with the spreadsheet. Zijun aided in the project’s completion by building a model of the combustion reactor and its inlets and outlets. This allowed for the final energy balance to be completed which led to the ability to determine the amount of electricity that can be used and sold. From here, he developed all of the economic calculation tables and the performed the analysis on those
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sections. Then, he wrote up his findings in the economic analysis section and also in the economic calculations appendix. Aaron contributed to the project through support calculations here and there to supplement the rest of the team. He also performed extensive research into areas where the team required additional information for continued work. His major contribution to the report was through the writing of the safety and environmental sections. These sections required a large amount of research as well to evaluate the potential causes of concern in the plant.
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1. Introduction
1.1 Overall Goal The overall goal of the plant is to provide a potential method for producing algal biofuels from Chlorella sp. using current technologies for comparison to other transportation fuels and prices. The plant focuses on sustainability by maximizing the recycling of byproducts and minimizing energy costs and losses. The plant produces algae in open raceway systems using a designed growth media. Carbon dioxide exhaust from nearby production infrastructure is to be used to minimize the operating costs for the reactants. Hydrothermal liquefaction (HTLE) is utilized to maximize crude biofuel production with catalytic hydrothermal gasification (CHG) used to eliminate residual biomass and produce methane through an energy positive means. Enough algae are produced each day to fulfill 0.1% of Florida’s daily transportation fuel requirement. This relates to 255,932 kg of algae grown per day and results in 963 barrels of oil. Crude oil barrels are used as the basis for this production quantity to ensure that adequate amounts have been produced. The purity and quality of the crude oil out of the purification steps is compatible with the industry standard for sweet heavy crude oil. This means that the oil has a very low sulfur content and is still high in density. The one disadvantage is that the crude produced is high in nitrogen and oxygen. The oil is cleaned downstream to limit the nitrogen and oxygen problems. One major byproduct is produced in tandem with the plant’s main operations. The CHG process allows for methane to be produced, leading to a methane-rich output gas which can be sold to the grid after the needs of the facility have been fulfilled. This gas can either be cleaned up to sell as compressed natural gas in the marketplace or can be combusted and run through a generator to produce electricity to power the plant. Excess power can be sold to the grid as a byproduct.
1.2 Current Market Information The two output products of the process are electricity and crude oil from algae. An important step in determining the viability of the process is evaluating the quality of the products and gathering information on the markets. Determining product quality, product pricing, and demand for the products are vital for determining scale of the plant and making operating condition decisions to maximize profit.
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Current information on algae bio-oil is uncertain. Due to the composition of the crude oil being different from fossil fuel crude oil, there cannot be a definitive guess as to the exact quality of the oil being generated. One way to estimate the worth of the oil is to look at the elemental composition and density of the oil and compare that to fossil fuel crude oils and compare these qualities of the oil to standard values. Crude oil made from algae tends to be viscous, dense, and hard to work with untreated. Even after treating, the oil will still be of a density, approximately 860 kg/m3, which is high compared to the main standard crude oils (Brent and WTI). Based on the determination that the crude oil will be heavy sweet crude oil, an oil trading classification can be used to estimate the price of the product crude oil produced. Figure 1.1 shows a graph of density of crude oil versus sulfur content along with the approximated density and sulfur content for the product crude oil listed. While the closest two classifications for the product crude oil are Daqing and Bonny Light, Bonny Light is the only one with reliable historical data. A graph of Bonny Light oil prices is listed below in Figure 1.2. When compared to common crude oil standards such as Brent and WTI Blend, the price of Bonny Light oil is higher. This is favorable outcome, as it can be expected that the product crude oil can be sold at a price higher than standard crude oil classifications.
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Figure 1.1 – Crude Oil Density vs. Sulfur Content
Figure 1.2 – Cost of Bonny Light Crude Oil
(U.S. Landed)
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Electricity price, unlike for oil, is easy to determine due to the amounts of historical data that are available and almost no variation in quality of electricity based on source (Theodore Kury). Figure 1.3 is a listing of electricity prices of Florida and neighboring states over an eighteen year period. It is determined that the price of residential energy is going up in Florida over the past decade much faster than neighboring states. This is important due to the fact that the net electricity of the process allows for the sale of excess electricity back into the grid. The final piece of determining the current market is demand of the products. This, at least presently, is a simple problem as electricity and crude oil are two of the most demanded products in the world. Energy is the most valued commodity and is a major portion of the world’s most profitable companies. Even over the thirty year lifetime of the process, there is little doubt as to the demand of energy products, especially energy coming from a renewable source.
Figure 1.3 – Electricity Costs over Time for the Southeastern United States
(Theodore Kury)
1.3 Project Premises and Assumptions The design hinges on the use of two key technologies. The first is hydrothermal liquefaction which is used to break down residual biomass into additional crude oils. This process allows for the oil production to be maximized throughout the plant to produce the high value crude oil product by converting biomass into additional oils and hydrocarbon chains. The second technology utilized in the process is catalytic hydrothermal gasification. This method of
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biomass conversion allows for residual biomass to be converted into a moderate energy gas comprised of methane and carbon dioxide. Burning this gas should account for the majority of the plant’s electricity requirements and any excess power can be sold back to the grid. The CHG section of the process is based off of information provided by Genifuel. The use of these two technologies is the only given guideline for the project. Several major assumptions are made to simplify the design somewhat. The first big assumption is that the growth rate of algae can be stabilized in the system at all times. The second is that the lab scale experimental data for HTLE, CHG, and the downstream oil cleaning can be successfully scaled up without losses in productivity or efficiency. Another is that the oil projections from today can accurately predict the future with respect to the cost of oil. The last major assumption is that the oil produced from this plant is comparable to fossil fuels currently in use and is similar in quality and chemical makeup. These assumptions drive the plant’s design along with other assumptions listed in Appendix D.
***This report is written assuming a base knowledge in algal growth literature and processes associated with the growth, dewatering, extraction, and refining of the oils.
2. Process Description, Rationale, and Optimization
Sections 5.1 through 5.5 contain figures associated with the design and operation of the plant. They include the block flow diagram, the separate rooms of the process flow diagram, the equipment tables, the stream tables, and the utility table. Afterwards, a written description of the process design, rationale, and optimization is provided in Sections 5.6 and 5.7.
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2.1 Block Flow Diagram – Figure 2.1
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2.2 Process Flow Diagram – Figure 2.2
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3
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2.3 Equipment Tables
Table 2.1
Table 2.2
Table 2.3
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Table 2.4
Table 2.5
Table 2.6
Table 2.7
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2.4 Stream Tables
Table 2.8 Stream 1 2 3 4 5 6 7 8 9 10 11 Pressure (bar) 1 1 1 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 25 25 25 25 25 25 25 25 Vapor Fraction 0 1 0 0 0 0 1 0 0 0 0 Total Mass Flow 25.59 8633000 0 302.4 128200 128200 863300 0 60 1282000 1282000 Water 0 0 0 6 128000 128000 0 0 60 1280000 1280000 Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Carbon Dioxide 0 1862000 0 0 0 0 186200 0 0 0 0 Flue Gas (-CO2) 0 6771000 0 0 0 0 677100 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass 0 0 0 0 0 0 0 0 0 0 0 Bio-oil Waste 0 0 0 0 0 0 0 0 0 0 0 Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 296.4 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae 25.59 0 0 0 255.9 255.9 0 0 0 2559 2559 Refined Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 12 13 14 15 16 17 18 19 20 21 22 Pressure (bar) 1 1 1 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 25 25 25 25 25 25 25 25 Vapor Fraction 1 0 0 0 0 1 0 0 0 0 0 Total Mass Flow 86330 0 600 12820000 12820000 8633 0 6000 1.28E+08 1.28E+08 1.28E+08 Water 0 0 600 12800000 12800000 0 0 6000 1.28E+08 1.28E+08 1.28E+08 Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Carbon Dioxide 18620 0 0 0 0 1862 0 0 0 0 0 Flue Gas (-CO2) 67710 0 0 0 0 6771 0 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass 0 0 0 0 0 0 0 0 0 0 0 Bio-oil Waste 0 0 0 0 0 0 0 0 0 0 0 Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae 0 0 0 25590 25590 0 0 0 255900 255900 255900 Refined Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 23 24 25 26 27 28 29 30 31 32 33 Pressure (bar) 5 1 161 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 25 25 25 25 25 25 25 25 Vapor Fraction 0 0 0 0 0 0 0 0 0 0 0 Total Mass Flow 1.28E+08 1082000 1082000 127100000 1.27E+08 0 2546000 2546000 1.31E+08 1.31E+08 1293000 Water 1.28E+08 825600 825600 127100000 1.27E+08 0 2546000 2546000 1.31E+08 1.31E+08 1293000 Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Carbon Dioxide 0 0 0 0 0 0 0 0 0 0 0 Flue Gas (-CO2) 0 0 0 0 0 0 0 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass 0 0 0 0 0 0 0 0 0 0 0 Bio-oil Waste 0 0 0 0 0 0 0 0 0 0 0 Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae 255900 255900 255900 0 0 0 0 0 0 0 0 Refined Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 34 35 36 37 38 39 40 41 42 43 44 Pressure (bar) 1 161 161 161 1 161 161 161 161 1 1 Temperature (Celsius) 25 344.7 350 350 25 350 350 350 35 35 25 Vapor Fraction 0 0 0 0 0 0 0 0 0 0 0 Total Mass Flow 1.29E+08 1082000 1082000 4697 4697 1077000 1077000 1079000 1079000 1079000 109100 Water 1.29E+08 825600 825600 0 0 825600 825600 825600 825600 825600 0 Bio-oil 0 0 0 0 0 0 0 109100 109100 109100 109100 Carbon Dioxide 0 0 0 0 0 0 0 0 0 0 0 Flue Gas (-CO2) 0 0 0 0 0 0 0 0 0 0 0 Potassium 0 0 0 33.39 33.39 0 0 0 0 0 0 Residual Biomass 0 0 0 0 0 0 0 143900 143900 143900 0 Bio-oil Waste 0 0 0 0 0 0 0 0 0 0 0 Phosphate 0 0 0 2319 2319 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae 0 255900 255900 0 0 251200 251200 0 0 0 0 Refined Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Sulfate 0 0 0 2345 2345 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 45 46 47 48 49 50 51 52 53 54 55 Pressure (bar) 166 1 200 200 200 200 200 1 1 1 1 Temperature (Celsius) 25 25 25 273.6 300 300 35 35 25 25 25 Vapor Fraction 0 0 0 0 0 0 0 0.1371 0 0 1 Total Mass Flow 109100 969600 969600 969600 969600 898600 898600 898600 796000 796000 102700 Water 0 825600 825600 825600 825600 764000 764000 764000 764000 764000 0 Bio-oil 109100 0 0 0 0 0 0 0 0 0 0 Carbon Dioxide 0 0 0 0 0 61520 61520 61520 20510 20510 41010 Flue Gas (-CO2) 0 0 0 0 0 0 0 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass 0 143900 143900 143900 143900 0 0 0 0 0 0 Bio-oil Waste 0 0 0 0 0 0 0 0 0 0 0 Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 61660 61660 61660 0 0 61660 Algae 0 0 0 0 0 0 0 0 0 0 0 Refined Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 11400 11400 11400 11400 11400 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 56 57 58 59 60 61 62 63 64 65 66 Pressure (bar) 1 1 1 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 1990 1934 1922 1884 25 25 25 25 Vapor Fraction 1 1 1 1 1 1 1 0.8805 0 0 1 Total Mass Flow 102700 1059000 1059000 1161000 1161000 1161000 1161000 1161000 138700 138700 1022000 Water 0 0 0 138700 138700 138700 138700 138700 138700 138700 0 Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Carbon Dioxide 41010 0 0 210600 210600 210600 210600 210600 0 0 210600 Flue Gas (-CO2) 0 0 0 0 0 0 0 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass 0 0 0 0 0 0 0 0 0 0 0 Bio-oil Waste 0 0 0 0 0 0 0 0 0 0 0 Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 246700 246700 0 0 0 0 0 0 0 0 Methane 61660 0 0 0 0 0 0 0 0 0 0 Algae 0 0 0 0 0 0 0 0 0 0 0 Refined Bio-oil 0 0 0 0 0 0 0 0 0 0 0 Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 811900 811900 811900 811900 811900 811900 811900 0 0 811900
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Table 2.8 continued Stream 67 68 69 70 71 72 73 74 75 76 Pressure (bar) 1 1 1 1 1 166 166 166 166 1 Temperature (Celsius) 25 25 25 25 25 383 388 388 35 35 Vapor Fraction 1 1 1 1 1 0 0 0 0 0 Total Mass Flow 9382000 9382000 10400000 103000 10300000 109100 109100 109100 109100 109100 Water 0 0 0 0 0 0 0 0 0 0 Bio-oil 0 0 0 0 0 109100 109100 0 0 0 Carbon Dioxide 1858000 1858000 2069000 20480 2048000 0 0 0 0 0 Flue Gas (-CO2) 7524000 7524000 7524000 74490 7449000 0 0 0 0 0 Potassium 0 0 0 0 0 0 0 0 0 0 Residual Biomass 0 0 0 0 0 0 0 0 0 0 Bio-oil Waste 0 0 0 0 0 0 0 11220 11220 11220 Phosphate 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 Algae 0 0 0 0 0 0 0 0 0 0 Refined Bio-oil 0 0 0 0 0 0 0 97860 97860 97860 Sulfate 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 Media Inputs 0 0 0 0 0 0 0 0 0 0 Nitrogen 0 0 811900 8039 803900 0 0 0 0 0
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Table 2.8 continued Stream 1 2 3 4 5 6 7 8 9 10 11 Pressure (bar) 1 1 1 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 25 25 25 25 25 25 25 25 Vapor Fraction 0 1 0 0 0 0 1 0 0 0 0 Total Kilomolar Flow Rate 0 42320 0 9.595 7109 7109 4232 0 3.333 71090 71090 Water 0 0 0 0.3333 7109 7109 0 0 3.333 71090 71090 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 0 42320 0 0 0 0 4232 0 0 0 0 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 9.261 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 12 13 14 15 16 17 18 19 20 21 22 Pressure (bar) 1 1 1 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 25 25 25 25 25 25 25 25 Vapor Fraction 1 0 0 0 0 1 0 0 0 0 0 Total Kilomolar Flow Rate 423.2 0 33.33 710900 710900 42.32 0 333.3 7109000 7109000 7109000 Water 0 0 33.33 710900 710900 0 0 333.3 7109000 7109000 7109000 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 423.2 0 0 0 0 42.32 0 0 0 0 0 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 23 24 25 26 27 28 29 30 31 32 33 Pressure (bar) 5 1 161 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 25 25 25 25 25 25 25 25 Vapor Fraction 0 0 0 0 0 0 0 0 0 0 0 Total Kilomolar Flow Rate 7109000 45870 45870 7063000 7063000 0 141400 141400 7255000 7255000 71830 Water 7109000 45870 45870 7063000 7063000 0 141400 141400 7255000 7255000 71830 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 0 0 0 0 0 0 0 0 0 0 0 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 34 35 36 37 38 39 40 41 42 43 44 Pressure (bar) 1 161 161 161 1 161 161 161 161 1 1 Temperature (Celsius) 25 344.7 350 350 25 350 350 350 35 35 25 Vapor Fraction 0 0 0 0 0 0 0 0 0 0 0 Total Kilomolar Flow Rate 7183000 45870 45870 49.66 49.66 45870 45870 45870 45870 45870 0 Water 7183000 45870 45870 0 0 45870 45870 45870 45870 45870 0 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 0 0 0 0 0 0 0 0 0 0 0 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0.854 0.854 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 24.41 24.41 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 0 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 24.4 24.4 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 45 46 47 48 49 50 51 52 53 54 55 Pressure (bar) 166 1 200 200 200 200 200 1 1 1 1 Temperature (Celsius) 25 25 25 273.6 300 300 35 35 25 25 25 Vapor Fraction 0 0 0 0 0 0 0 0.1086 0 0 1 Total Kilomolar Flow Rate 0 45870 45870 45870 45870 48370 48370 48370 43580 43580 4786 Water 0 45870 45870 45870 45870 42450 42450 42450 42450 42450 0 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 0 0 0 0 0 1398 1398 1398 466 466 932.1 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 3854 3854 3854 0 0 3854 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 670.6 670.6 670.6 670.6 670.6 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 0 0 0 0 0 0 0 0 0 0
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Table 2.8 continued Stream 56 57 58 59 60 61 62 63 64 65 66 Pressure (bar) 1 1 1 1 1 1 1 1 1 1 1 Temperature (Celsius) 25 25 25 1990 1934 1922 1884 25 25 25 25 Vapor Fraction 1 1 1 1 1 1 1 0.8142 0 0 1 Total Kilomolar Flow Rate 4786 36700 36700 41490 41490 41490 41490 41490 7708 7708 33780 Water 0 0 0 7708 7708 7708 7708 7708 7708 7708 0 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 932.1 0 0 4786 4786 4786 4786 4786 0 0 4786 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0 0 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 0 0 0 0 0 0 0 0 Oxygen 0 7708 7708 0 0 0 0 0 0 0 0 Methane 3854 0 0 0 0 0 0 0 0 0 0 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 29000 29000 29000 29000 29000 29000 29000 0 0 29000
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Table 2.8 continued Stream 67 68 69 70 71 72 73 74 75 76 Pressure (bar) 1 1 1 1 1 166 166 166 166 1 Temperature (Celsius) 25 25 25 25 25 383 388 388 35 35 Vapor Fraction 1 1 1 1 1 0 0 0 0 0 Total Kilomolar Flow Rate 42230 42230 76020 752.6 75260 0 0 0 0 0 Water 0 0 0 0 0 0 0 0 0 0 Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Carbon Dioxide 42230 42230 47020 465.5 46550 0 0 0 0 0 Flue Gas (-CO2) N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Potassium 0 0 0 0 0 0 0 0 0 0 Residual Biomass N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Bio-oil Waste N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Phosphate 0 0 0 0 0 0 0 0 0 0 Oxygen 0 0 0 0 0 0 0 0 0 0 Methane 0 0 0 0 0 0 0 0 0 0 Algae N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Refined Bio-oil N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Sulfate 0 0 0 0 0 0 0 0 0 0 Ammonia 0 0 0 0 0 0 0 0 0 0 Media Inputs N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Nitrogen 0 0 29000 287.1 28710 0 0 0 0 0
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2.9 Utility Table
Table 2.2 – Utility Table Utilities Water $/gal gallons/year $/year 0.000075 245500000 18410 Electricity $/kW*hr kW*hr/year 0.17 -111800000 -19000000 Total -18980000
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2.6 Process Description Due to the size of the plant, it should be noted that the process flow diagram shows the flow of an individual batch of algae without specifying the exact number of each type of equipment. For instance, while only one set of raceways is depicted, the scope of the plant actually requires 394 of these raceway systems to be developed and built with each raceway system having one raceway of each size. The correct quantity required for each equipment piece is given in Tables 2.1 through 2.7. Streams are denoted throughout the process description and refer to Table 2.8 which lists out the content, phase, temperature, and pressure for each of the flows through the system. This table directly relates to the streams labeled on Figure 2.2 which is the process flow diagram. The figure consists of four separate images to show different sections of the plant. Despite being split in this manner, the four images are highly interconnected through the inlet and outlet streams that recycle compounds and energy through the plant. The process begins with the growth section of the plant used to expand and grow algal cultures for use in the plant. The proposed growth method utilizes four different sizes of raceway for each batch of algae. To begin the process, a small scale raceway (RW-101) is filled to 90% volumetric capacity with a growth media made up of mostly water along with a series of nutrients. The specific growth media composition is listed as a combination of a variety of chemicals dissolved in water as denoted is Appendix F and is pumped in from Room 200 as Streams 3, 8 13, and 18 to each raceway size. The smallest raceway (RW-101) is also inoculated with a pure algae culture at a concentration of 0.2 g/L to begin growth through Stream 1. Carbon dioxide flows through each raceway as the carbon source through Streams 2, 7, 12, and 17 and is put through a sparger at the bottom of the raceway to create bubbles of relatively small diameters to facilitate the diffusion of carbon dioxide throughout the growth media. Excess carbon dioxide has to be pumped through as the diffusion rate is not fast enough despite the small bubble diameter of 1 mm. These losses are summed up in Stream 4, 9, 14, and 19 respectively along with water losses to evaporation and oxygen gas outputs from photosynthesis performed by the algae itself. After the culturing time of approximately 8 days for a dilution rate of 10 has been completed for each raceway, the algae reaches a concentration of 2 g/L in the media and is pumped into the next biggest raceway system. The raceway sizes increase from small scale to bathtub sized to medium and finally to large scale. Since the dilution ratio remains constant across all of the raceway setups and sizes (RW-101 to RW 104), one pump can be used for all of the raceway sizes although this
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means that the pump must be mobile. The pump will be mounted onto the back of a truck to facilitate transportation to the various raceways. Also, the pumping for each set of raceways will only take a day or less each. This means that a single pump can be used to move growth media from 8 different raceway systems. This number is equal to the culturing time required for each system and also that P- 101 to P-104 can actually all be accomplished by a single pump. This leads to the total number of pumps mounted in this way to 56 including spares. The reasoning behind establishing the pumping system this way is explained in Section 2.7. After going through each of the four raceway sizes, the algae mixture is pumped (P-105) into a system of holding tanks (TK-101) designed to hold the dilute product. This tank system allows for a time delay to be implemented that will turn the system from a batch reactor style growth model into a continuous process. This is accomplished by storing enough algae on hand at all times to keep the downstream systems running constantly despite the inconsistent inflow of concentrated algae growth media coming in each day. From this tank system, the solution is pumped continuously into Room 200 which models the ambient operations of the plant. The pump also slightly increases the pressure of the liquid to 5 bar. Once in Room 200, the slightly pressurized liquid flows into a filter (F-201) which serves to increase the solids concentration of the fluid. Streams 24 and 26 leave the filter system where Stream 26 consists only of growth media and Stream 24 has a high solid content of algae. This assumes an efficiency of essentially 100% in the filter system due to the presence of four filters in series. A further explanation of the filter system is described in Section 3.6 below. Stream 24 flows through a pump (P- 201) into Room 300 which deals with hot operations as the pressure is raised to 161 bar. Stream 26 is also pumped (P-202) away from the filter and back into a media generation and recycle mixer (M-201). This mixer serves to combine water and recycled media from throughout the plant with new nutrients in Stream 28. The mixer also takes in fresh water pumped (P-203) through Stream 30 to offset losses in the plant. The media is then sent through a pump (P-204) into a system of valves. These valves (V-201 to V-203) separate the media into four different streams at the appropriate flow rates to be fed back into each of the raceways as Streams 3, 8, 13, and 18. The valve system also helps to replace water losses to evaporation every few days in the raceways. The concentrated algal media in Stream 25 has a concentration of approximately 23.7% and is pumped (P-201) into Room 300 to be processed. The first step is to feed the media through a pair of
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heat exchangers (HTX-301 and HTX 302) which will effectively raise the temperature of the stream to 350°C. After being heated and pressurized, the water in the media will exist in a state just slightly below being supercritical which allows for essentially all organic material to be dissolved in it. Due to this property, the media ceases to be a mixture and instead operates as a liquid. However, sulfates and phosphates are basically insoluble in water under these conditions which allows them to precipitate out. The media flows into a precipitation tank (TK-301) where these phosphates and sulfates are allowed to precipitate and congregate at the bottom of the tank, purifying the stream so they do not have the chance to poison the catalysts downstream. These solids build up slowly over time in the bottom of the precipitation tank as Stream 37 and must be cleaned out at regular intervals. This can be done using a pressure release valve (V-301) and the solids are expelled from the system. These phosphates and sulfates could be reinitialized into fertilizers to be fed back into the media mixer in Room 200. After the precipitation tank, the algae stream moves as Stream 39 into a sulfur scrubber (R-301) which is packed with Raney nickel. The nickel serves to remove any extra sulfur from the fluid that could poison the more expensive catalysts downstream. From here, the fluid is pushed through the hydrothermal liquefaction reactor (R-302) where a packed bed of sodium carbonate serves to break down the algal cell walls and convert some of the biomass into a substance similar to crude algal oils. This also has the effect of allows the lipids and oils inside the algae to separate out. Afterwards, the stream flows back through the first heat exchanger (HTX-301) to recycle much of its heating energy as it lowers its temperature to 35°C. A pressure release valve (V-302) comes next to drop the fluid back down to an ambient pressure as it flows as Stream 43 into one of several massive separation tanks (TK- 302). These tanks serve to separate the organic and aqueous phases now that the operating conditions have been lowered. This allows for the oils to be extracted as Stream 44 and pumped (P-301) to Room 400 for further processing of the oil as Stream 45. The pump also increases the pressure of the oil to 161 bar. The aqueous phase now consists of primarily water as well as the residual biomass left over after the hydrothermal liquefaction treatment where the solids content is approximately 15%. This fluid is placed through a pump (P-302) and raised to an operating pressure of 200 bar. Then, the fluid is pushed through two more heat exchangers (HTX-303 and HTX-304) to raise the temperature of the stream to a temperature of 300°C in Stream 49. Once the water is nearly supercritical again, the stream is fed through another reactor (R-303) where the residual biomass interacts with the ruthenium catalyst
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inside. The ruthenium is mounted on a carbon structure which serves to convert the carbon of the residual biomass into a combination of carbon dioxide and methane. Other components include turning the nitrogen into ammonium ions. Due to the high temperature and pressure combination, the water keeps all of these compounds completely dissolved as it cools back into a heat exchanger (HTX-303) to cool down and recycle its heat. The output from this heat exchanger is Stream 51 and exists at a temperature of 35°C. After passing through another pressure release valve (V-303), the fluid enters a phase separation tank (TK-303) which separates the liquid and gas phases. The flow is assumed to complete its cooling in the phase separation tank and the pipes leading in and out of it as per Assumption 20 in Appendix D. As the pressure and temperature are lowered, the methane cannot stay dissolved in the water along with approximately 89% of the carbon dioxide. These two gases form the vapor phase inside the separation tank while the liquid phase consists primarily of the remaining growth media. This liquid is saturated with carbon dioxide and contains the ammonium ions within it in addition to anything else from the media. This liquid stream is pumped (P-303) back to Room 200 as Stream 54 where it flows into media generation and recycle mixer (M-201) to be reused. The vapor phase becomes Stream 55 and is pushed through a fan (FA-301) into a combustion reactor (R-304) in Stream 56. Stream 57 draws in air from the environment and is fed through a fan (FA- 302) to reach the reactor as Stream 58. This effectively provides the oxygen for the combustion reaction to take place. The two gas streams are combined and ignited to create water and carbon dioxide from the methane and oxygen while letting off large amounts of heat. Stream 59 leaves the reactor at a very high temperature of 1990°C to provide extra heating throughout the plant. For each of the three heat exchanger pairs, the cold streams can only be heated to within 5°C of their required temperature due to the minimum temperature approach (Seider et al.). Stream 59 flows through HTX-304 as the hot stream before moving on to providing additional heating to HTX-302 as well. The vapor exits HTX-302 as Stream 61 at a temperature of 1922°C. Stream 61 moves from Room 300 to Room 400 to become the hot stream in HTX-402. The final output vapor from this heat exchanger becomes Stream 62 and flows at an operating temperature of 1884°C. From here, the vapor flows back into Room 200 where it flows into an electric generator. The generator takes the remaining heat energy from the vapor and converts it into electrical power using a turbine setup. Stream 63 comes out of the generator and consists of a vapor and liquid mixture which flows into a phase separation tank (TK-201). The liquid phase is pumped (P-205) out of the tank into the
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water recycle system as Stream 65 flows into the media generation and recycle mixer (M-201) to be the final water recycle stream. The vapor phase is composed of carbon dioxide and is expelled as Stream 66 into a fan (FA-202). This stream is mixed with additional carbon dioxide from any source that is input as Stream 67 and moved through a fan (FA-201). The combined gases become Stream 69 which is fed into a valve system (V-204 to V-206) which separates the carbon dioxide gas into the appropriate flow rates. The valve system outputs become Streams 2, 7, 12, and 17. These streams are then fed into each of the growth raceways as the carbon source for algal growth. Returning to Room 400, the crude oil input in Stream 45 is pushed through a pair of heat exchangers (HTX-401 and HTX-402) to raise the temperature to 388°C. Combined with the pressure increase from Room 300, the oil is fed into a final reactor (R-401) that serves to clean up the crude oil. The oil prior to the reactor contains oxygen and nitrogen levels that are too high to sell into the market as heavy sweet crude oil. The reactor is filled with cobalt and molybdenum on aluminum oxide which serves as a catalyst to clean up the oil by converting the excess amounts of oxygen and nitrogen into compounds that can be removed from the oil. After the cleaning, the fluid is then sent back through the first heat exchanger (HTX-401) to provide most of the heating for the incoming oil. After dropping the temperature, a pressure release valve (V-401) is used to drop the pressure back to ambient conditions. The final output stream is Stream 76 where the heavy sweet crude oil is output as the primary product from the system.
2.7 Process Rationale and Optimization The process design has multiple optimizations that generate advantages over other proposed algal systems. The first of these comes from the use of raceways as the algal growth environment instead of photobioreactors. Photobioreactors are typically associated with higher growth rates and less contamination at the cost of much higher energy costs for the system. Since one of the project objectives was to improve the algae energy balance, raceways were selected in tandem with the use of other means to counteract the disadvantages. To limit the potential for contamination from other microorganisms, slight amounts of salt are introduced to make the environment less sustainable to other types of algae and parasites without sacrificing growth rates. The use of raceways also requires only natural lighting to stimulate growth while photobioreactors can often require artificial light sources. From a mass balance standpoint, while the raceways do allow for evaporative losses from the system,
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they also release the produced oxygen from photosynthesis. The same oxygen in a photobioreactor can easily build up and poison the bacteria, halting growth and oil production. For these reasons, raceways are chosen as a more practical option with a lesser effect on capital costs. Another key piece of the process optimization is the limitation of pumps onsite. This refers both to the required pumps and the possession of spares in case of equipment failures. The pump optimization focuses on limiting the number of transfer pumps that transfer inoculated media from raceway to raceway. First off, a single pump (P-104) that can handle the required flow rate for the biggest raceway can also be used for each smaller raceway size. Assuming that it takes 24 hours to transfer the media from all four raceways in a given raceway system, the number of raceways that one pump can take care of is equal to the number of days in each cultivation period. In this design, only one pump (P-104) is needed for each set of eight raceway systems as the cultivation is calculated to be eight days (See Appendix A for further timing details). Since all of the pumps are the same size, an individual backup for each pump is not necessary as it is unlikely that many of the pumps will break at the same relative time. This means that even though 56 raceway transfer pumps are needed, 6 spare pumps should be adequate to keep the plant constantly producing at the desired rate. The principle is also used at other locations throughout the plant. Since all of the tanks and reactors have more than one copy that runs in parallel, the spare pumps going into those sections can also be minimized. This simple reduction serves to drastically cut down on the capital costs of the plant. One last slight optimized choice coming out of the growth stage is the placement of tanks (TK- 101) that essentially just store the concentrated algal media. These were added late in the design to turn the flow of the plant from a batch process into a continuous flow. The continuous nature allows for the plant to continue operating at all times while the tanks also allow for some of the product to always be kept on hand. This allows for the plant to continue the processing stages even if there is a disturbance in the growth section such as a contamination in one of the batches. The continuous nature of the plant becomes critical to maintaining productivity as well as for properly sizing the equipment. It also allows for the calculation of the correct number of reactor systems that are needed downstream based on continuous flow residence times. Without this, the plant would require more reactor systems and would operate at a lower efficiency. Since the major product of the plant is a sustainable liquid transportation fuel source, recycling should be used as much as possible both to cut down on the environmental impact and to lower
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expenses. Recycle streams are employed for both the water system and the energy requirements. The more obvious recycle comes from the water reclamation system that pools together all water sources from throughout the plant to generate the growth media inside of the mixer (M-201). This water is recycled from three separate locations throughout the plant which helps to alleviate the losses due to evaporation in the growth raceways and to lower the utility costs by an appreciable amount. The second recycle system uses heat from the combustion reactor (R-304) onsite to provide the last 5°C of necessary heating in each heat exchanger pair (HTX-302, HTX-304, and HTX-402) instead of buying additional electricity to provide the heat energy. Since the outlet temperature of the combusted methane gas is so high, it is practical to use this vapor to avoid the minimum temperature approach in the heat exchangers. Since the heating process through a heat exchanger is much more efficient than an electrical heater, this saves a significant amount of energy that would have otherwise been lost to the system. The plant’s design also attempts to eliminate some of the current problems with the algal biofuel plant design. Essentially, it is becoming more obvious that the dewatering, drying, and extraction steps of the process create massive energy sinks that cost too much to deal with on a large scale. The plant attempts to handle both of these problems by processing the wet algae without going through an extensive dewatering procedure. Then, it should be possible to perform liquid-liquid extraction on what remains. The first major optimization on the algae life cycle is to eliminate the dewatering step entirely. Rather than trying to obtain a dry algal flow, the plant utilizes a filtration system (F-201) similar to that of a reverse osmosis system. The media flows through a series of tubes with a very fine pore size cut into them. Essentially, the pore size is much too small compared to the average diameter of the algae which keeps the vast majority of the algae in the waste stream. The slight transmembrane pressure drop allows vast amounts of the media to leave as a permeate stream while the waste stream becomes highly concentrated with algae. The filtration system requires essentially no energy and is faster than the most other dewatering processes. Overall, this wet processing idea is relatively cheap and the resulting waste stream becomes the product stream for further processing. As mentioned above, the next major hurdle after dealing with dewatering and bypassing drying is to actually extract the oil from within the algae. The plant handles this problem by utilizing hydrothermal liquefaction in a packed bed reactor (R-302). Due to the high pressures and temperatures
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associated with HTLE, the biomass converts part of itself into oils and preliminary oil structures such as fatty acids. As this process occurs on the cell membranes of the algae, the membranes should rupture and allow for the release of the oils within the cells. This provides a chemical solution to the extraction problem while also producing additional oils, making it an optimal solution from both a production and an energy standpoint. Before moving further downstream, it should be noted that the presence of the precipitation tank (TK-301) and the sulfur scrubber (R-301) are a critical optimization for the longevity of the catalysts. The interactions between phosphates or sulfates and heavy metal catalysts are parasitic. The sulfates in particular bond to the active sites of the catalysts extremely easily and remain there for long periods of time. While the near-supercritical water does have a slight cleaning property for removing this poisonous effect, it can drastically reduce the reliability of the catalyst. Therefore, the precipitation tank and sulfur scrubber combination serve to eliminate the threat associated with these types of compounds. The precipitation tank provides a collection location for precipitated solids that can be collected periodically and potentially regenerated into fertilizers again. The sulfur scrubber is a packed bed reactor where the catalyst is cheap and uses its active sites to trap sulfates and phosphates that slip through the precipitation tank. This catalyst can be disposed of responsibly and inexpensively, allowing the more expensive catalysts to remain completely active. One of the potential problems associated with processing a wet algal feedstock is separating the oil and other organic compounds from the aqueous portions of the mixture. There are several methods that can accomplish this separation yet most are costly or have large energy expenditures. In this design, large tanks (TK-302) are used with a relatively large residence time that will allow for the density difference and molecular compatibility issues to cause a phase separation. The phases can then be pumped away for further processing from here using P-301 and P-302. This solution relates to a potentially higher capital cost yet essentially eliminates the operating costs for this stage of the process. This tradeoff should make up for the higher upfront costs over time. The last optimization for the crude oil production comes from the deoxygenation and denitrification reactor (R-401). Literature sources show that both oxygen and nitrogen can be removed from crude oil using a packed bed reactor filled cobalt and molybdenum on aluminum oxide. With a high temperature and pressure, the crude oil can be cleaned up significantly to create a higher quality product. Since the conditions for both processes are relatively equal, the process simply performs both
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steps simultaneously by using the larger residence time and the higher temperature and pressure conditions. This should allow for a single reactor to be satisfactory instead of two, cutting down on equipment costs for both the second reactor and the auxiliary heat exchangers and pumps that would be required by a two reactor setup.
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3. Equipment Description, Rationale, and Optimization: For this section, each equipment type will be a separate subsection to allow for easier referencing. Each equipment piece will be described and labeled along with a rationale for why the specific design characteristics were chosen. Any optimization will be discussed afterwards. Additional details are provided in the equipment tables (Tables 2.1 to 2.7) with the appropriate calculations outlined in Appendix A.
3.1 Raceways: All raceways are designed as a form of open tank that allow inoculated growth media to flow around in circles as algae grow within them. These systems are dug into the ground to a depth of 40 centimeters in a large, oval-like shape. The length and width of each raceway is altered to maintain a constant length to width ratio (L/W = 5/3) across each of the raceway sizes. The design was based off of a dilution ratio of 10 so that the algae must be moved when the algal concentration has increased tenfold in the current raceway. This means that the volume from one raceway is ten times bigger than the next biggest size. The raceways are built by lining the dug trenches with PVC material to contain the media from seeping into the dirt environment. The PVC was chosen based on its cheap yet effect nature. Since the media has a relatively standard pH and no ingredients that can cause significant material decay, PVC can easily handle the media regardless of the extended growth times and the constant media movement through the raceway. In addition to the lining, the raceways are set apart from open holding tanks though due to the presence of a paddlewheel. The paddlewheel is a constantly rotating piece of equipment that serves to keep the growth media constantly flowing through the raceway. This serves to stop the algae from stagnating in the raceway while causing some mixing to occur, allowing the algae to maintain the constant acquisition of nutrients for growth and oil production. The last major piece of the raceway is the sparger that lies along the bottom. The sparger is perforated with tiny holes that control the diameter of gas bubbles that are allowed through. The sparger can be made of several different materials such as metal or PVC and can be set at whatever hole diameter is desired for the system. This diameter will significantly affect the diffusion rate of carbon dioxide which can be used to limit the total required flow rate through the system.
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Raceways were chosen due to their cheap solution compared to photobioreactors or ponds. Photobioreactors are typically considered much more expensive both in capital and operating costs with the benefits of lowered contamination and higher oil production and growth rates. Algae ponds have the lowest growth rates with their standard batch operation but have essentially no operating costs and much lower capital costs. Contamination and low nutrient uptake rates are significant problems for this setup though. The raceway growth chambers are the middle ground in all of these areas and have been designed to minimize the economic issues associated with advanced algal growth systems while still maintaining a relatively high productivity. Arguably the most important aspect of the raceway to optimize is the depth of the raceway. At 40 centimeters, the raceway depth is optimized to allow for several different reasons. First off, the media is deep enough to accommodate a relatively large amount of algal biomass by increasing the volume. The deeper media also means that less carbon dioxide has to be pushed through the raceway since there is a larger time lapse between the bubble leaving the sparger and exiting the media. The depth must be limited though as sunlight penetrates the media less as the depth increases too far. This leads to an optimal depth range between 30 and 50 centimeters. It should be noted that four different raceway sizes are used in this model based on the chosen dilution ratio. Increasing the dilution rate will allow for less raceways sizes to be needed at the expense of requiring a longer cultivation time in each raceway. This optimal range of the dilution rate was decided to be between 5 and 12 depending on how well each batch can be controlled. As the cultivation time is increased, contamination becomes a bigger concern as a larger batch of both algae and media would be lost. However, the operating costs could be lowered by having less paddlewheels to have to deal with as well as lowering the capital costs by requiring less transportation pumps (P-104) in the network.
3.2 Heat Exchangers: The heat exchangers used throughout the plant can primarily be grouped into two different types. First are the liquid-liquid heat exchangers which exist primarily to recycle heat from a reactor’s exit liquid stream into a reactor’s inlet liquid stream. These heat exchangers are each set up in pairs with a corresponding liquid-gas heat exchanger. The liquid-gas heat exchanger is used to get around the minimum temperature issue in the primary heat exchangers. Because of the limitations associated with
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transferring all of the heat from one fluid to another, it is generally accepted that the outgoing temperature of the cold stream can only be raised to 5°C less than the incoming temperature of the hot stream. Due to this, the secondary heat exchangers allow for a high temperature gas to transfer the last 5°C for each inlet reactor stream. Depending on the phases of both the hot and cold streams, the heat transfer coefficient will be changed for the individual heat exchanger. A liquid-liquid exchanger has a higher heat transfer coefficient of 50 while a liquid-gas exchanger is ten times lower at 5. This difference leads to a drastic difference in the heat transfer area within the exchanger types. Across all three pairs, the liquid-gas heat exchangers have substantially higher areas associated with a much smaller temperature change. All of the heat exchangers are made of carbon steel to limit the costs of construction. The pressure and temperatures of the streams entering and exiting the heat exchangers are not extreme enough for a more durable material to be required. Therefore, carbon steel can be used as a low cost building material. All of the heat exchangers of designed as fixed head shell and tube heat exchangers. The fixed head method is the cheapest method for the operating heat transfer areas required while the shell and tube designation is used to simplify the construction and design. The true optimization of the heat exchanger systems is to utilize heat that would otherwise be used to generate electricity in a generator. After the combustion reactor (R-304), the high temperature gas eventually flows into a generator (G-201) to generate electricity at an efficiency of about 55%. This power could then be used in an electric heater to provide the necessary heat as a replacement for the liquid-gas heat exchangers. However, this occurs at an efficiency substantially lower than 100%. By using these secondary heat exchangers instead, the heat is transferred at essentially 100% efficiency which means that the energy is recycled much more thoroughly. This saves on a substantial operating cost at the expense of a higher capital cost.
3.3 Pumps: Throughout the plant, nine different sizes of pumps are required to move liquids around. There are two different types of pumps though depending on the required task. Since most of the reactors demand high pressures, pumps have to create these pressure effects on the incoming liquid before each reactor can be utilized. These pumps (P-201, P-301 through P-303) create intense pressure heads of over 2300 psi to keep the media and the crude oil from vaporizing as the temperatures are raised
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significantly. Because of the massive pressure increases, the horsepower necessary in these high pressure pumps is much higher than the other pumps despite the substantially lower flow rates. The second group of pumps is used only for transporting liquids without causing large pressure gains. These pumps (P-101 through P-104, P-202 through P-205) are used either to transport growth media from one raceway to another (RW-101 through RW-104) or to push media into the recycling system. While these pumps have significantly lower horsepower requirements overall, they also are responsible for much higher liquid flow rates through the system. This is especially true for P-202 which pumps the excess media out of the filtration system. All of the pumps are built out of cast iron in order to minimize the costs of the pumps. Cast iron has been shown to be able to handle the high pressures throughout the system without any issues. This allows the material to be utilized given proper construction methods. The pumps are based on a centrifugal pump design because of its widespread use in most processes and are the most understood method of pump construction. The pumps are also characterized by the case-split orientation which is a function of flow rate, pump head, and maximum horsepower. The choices for each pump are based on information in Seider (p. 561). The true optimization of the pumps comes through the minimization of the number of spares that are needed in the system. The pumps can be split into three different groupings based off of horsepower requirements. These groupings are around 1 hp, 55 hp, and 500 hp. By grouping these pumps together, the price of each individual pump would be slightly higher but less spares would be needed. This directly causes lower capital costs due to the purchase of less pumps overall. The other major optimization comes from consolidating the raceway pumps into one single pump that can be used to service multiple raceway systems. The pump was sized to be able to transfer all of the media from each raceway to the next in a 24 hour period of time. The calculations to accompany this design are outlined in Appendix A which determines the maximum amount of time for each stage of the transfer process. This in turn gives the minimum flow rate needed to minimize the size of the pump overall. These pumps will be loaded onto the back of a truck to move the pump from raceway to raceway through the system. The easy movement and relocation limits the number of actual pumps in rotation while having a uniform size allows for the number of spares to be cut down by nearly 90%. This saves large amounts of money in capital costs for the plant.
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3.4 Fans: The plant requires four different fans in order to maintain continuous operation. While the flow rates vary dramatically, tube axial fans are used at all points in the process. These fans are better at moving high flow rates as opposed to increasing the discharge pressure of the gas. Since the acting discharge pressure is atmospheric, tube axial fans are better at performing for this plant. The fans could be split into two major categories based on their relative flow rate. It can be seen that, due to the large amount of carbon dioxide that must be moved through the system, FA-201 and FA-202 are much larger than the fans from Room 300 in the PFD (Figure 2.2). The two fans could be grouped together though to require only one spare to be purchased that could accommodate either flow rate. This means a reduction in capital costs for spares in the system. A similar idea could be applied to FA-301 and FA-302 since their flow rates are also fairly similar but are low enough compared to the fans in Room 200 that a unique spare should be purchased for this pair as well. All of the fans in the plant are made of carbon steel due to the relatively low flow rates and pressure gains in the gas streams. Carbon steel provides the lowest cost building material for the construction process.
3.5 Tanks: The tanks serve two different purposes in the plant. The first is to allow space where separations can occur in the liquid streams. For example, the precipitation tank (TK-301) lets the phosphate and sulfate compounds to precipitate out of the hot, pressurized media. The separation tanks (TK-302) grant the fluid time to form two distinct layers between the organic oil-based liquid and the remaining growth media and other dissolved particles that form the aqueous phase. These tanks are necessary since these types of separations take time to complete and the fluid should flow very slowly but continuously so that the separations are not disrupted yet the fluid also does not stagnate or build up. Nearly all of the tanks are designed and priced to be built of fiberglass. This material offers a very inexpensive method for containing fluids that are at relatively standard pressures and temperatures. The precipitation tank (TK-301) requires carbon steel though due to the high pressure and temperature of its contained fluids. Carbon steel is capable of handling this conditions at the lowest available cost.
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For this plant, most of the tanks will need to closed and sealed despite the increased capital costs. The presence of lids serves two purposes in the plant depends on the makeup of the tank’s contents. If the contents contain a vapor as in TK-201 and TK-303, the vapor is actually a desired product so the lid’s placement allows for more efficient harvesting of the vapor. In other tanks like TK- 301, the tank’s contents must remain highly pressurized which requires the use of a sealed tank.
3.6 Filters (F-201): The chosen filter is built out of a PVDF-9 membrane filter that works similarly to that of a reverse osmosis system. The membrane’s surface is perforated with concentrated holes with a diameter of 0.036 μm. At such a small diameter, it is essentially impossible for any algae cells to escape into the permeate media leaving the filter. The stated efficiency of the membrane is over 99% for solid particles yet due to the average size distribution of the chlorella, the observed efficiency should be even higher than that. The specifications for the filter give the maximum flux for the filter along with a surface area for the membrane itself. The two numbers allowed for the total number of required filters to be required assuming that the maximum is observed at all times. To account for any problems with this, the total number of filters was multiplied by four in order to run four filters in series. This should eliminate any losses in efficiency for a single filter. It should be noted that the membrane construction material has a slight setback in the pressures operating in the system. The current laboratory findings show that it could rupture if the transmembrane pressure drop exceeds 0.2 bar. The permeate flow rates still can be maintained at this pressure change which means that the control over the system would have to operate quickly. The filtration system will require a large series of valves and controllers in order to maintain the desired flow rates and separate the solution properly into the thousands of filtration units.
3.7 Generator (G-201): The generator operates by taking in a hot stream of gas from out of the combustion reactor (R- 304) that operates as the hot heat sink for a Rankin cycle setup. The heat transfers from the vapor input into the cycle’s working fluid, allowing it to move through the cycle and ultimately through a turbine to convert the kinetic energy into electricity. Optimization of the methane generators is extremely volatile
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right now as much research is being performed to increase the efficiency of these systems. For this reason, the generator itself has not been truly designed or optimized too much. This piece of equipment has a very large effect on the economics of the plant overall so the optimization of the generator would best be left to a specialty company and possibly even retrofitted throughout the plant’s lifetime to continue improving the efficiency.
3.8 Reactors: Five different types of reactors are required in the plant to convert the grown algae into crude oil products. Each of these reactors are priced as pressurized vessels but are built as horizontal packed beds. The horizontal orientation allows for less energy to be expelled moving the fluid through the reactor while the packed bed gives the best contact with the catalyst surface area. All of the reactors are built out of carbon steel due to the relatively cheap material costs while still being able to handle the high temperatures and pressures. The optimization for these reactors deals primarily with how the packed bed is set up and maintained. There are many tricks used to establish higher conversion rates in the reactors by packing the catalyst in certain ways and by changing the characteristic size of the catalyst particles. Since this packing methodology is highly specialized, it is necessary to bring in specialist contractors to optimize the reactors. Each reactor is packed with a different catalyst as listed in the equipment table (Table 2.7) with each catalyst causing a unique reaction on the fluid inside the reactor. The purpose of each catalyst is explained more in Section 2.6 above. The main sizing factor for the reactors is the weight of the building material. These reactors are built extremely thick to handle the high operating pressures and flow rates. The thickness of the material provides increased protection against leaks which could result in the loss of product and severe safety hazards.
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4. Safety and Environmental
4.1 Safety Analysis The proposed crude oil plant is designed with the highest safety standards in mind. The process utilizes a few hazardous chemicals and pieces of equipment that require special considerations for proper handling. Hazards in the plant also exist due to the operating conditions in the plant such as relatively high temperatures and pressures. By looking at the possible causes for injuries, precautions can be taken to avoid these hazardous events. Each of these three sources of safety concerns will be addressed thoroughly in turn.
Physical Hazards: The equipment used throughout the plant has inherent risks associated with their operations. The highest cause for concern is with the pressures and temperatures in Rooms 300 and 400 of the PFD (Figure 2.2). These conditions are seen in the heat exchangers (HTX-301 to HTX-304 and HTX-401 to HTX-402) and in the processing reactors (R-301 to R-303 and R-401). To prevent the hazard during operations, the plant would need a control system in place to monitor pressures throughout the equipment. Drops in pressure could be attributed to leaks in the system which would create weak points where nearly supercritical liquids could be rapidly ejected from the process equipment. This is the most serious concern in the plant and safeguards such as additional PPE and training should be utilized around the reactors and adjacent equipment. Pressure relief valves for this equipment would need to be placed around pressurized devices to provide a measure of protection against the buildup of pressure in the system. The other main equipment type with potential major safety concerns is the pumps. Due to high pressure heads in the pumps, the possibility of pump failure is higher than normal. With this in mind, pressures have a chance to build up and cause leaks or other problems in the system. Overall, with the exception of these pressure and temperature conditions, the equipment and operation is relatively safe as long as employees are properly trained and outfitted to deal with the equipment.
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Chemical Hazards: The chemicals used in the process could be potentially dangerous if abused. The two groups of chemicals are the growth media nutrients and the catalysts used within the reactors. Each of these groups is treated very differently in the system as their usage and availability onsite are very different. Both are discussed below for their relevant safety concerns. The growth nutrients are required in large quantities for use in the mixer (M-201). The compounds in the growth media are listed in Appendix F with their desired molarities in the media. This directly relates to the relative amounts of each chemical that must be stored onsite. Limits must be put in place to minimize the amount of each nutrient that is stored in the plant while still allowing the plant to operate at full capacity. None of the chemicals in the growth media have any major safety concerns as long as they are not directly inhaled or consumed. Once they are put into the water and mixed, any potential health effects are essentially nullified. The other class of chemicals in the plant is the catalysts. For the vast majority of the time, the catalysts are never seen by the operators and exposure is nearly impossible unless cleaning and servicing is being performed. Since the plant should be operating continuously at all times, the catalysts should stay in constant use at high pressures and temperatures. Potential exposure can occur though when the catalysts must be regenerated. This typically occurs every two years which will require the operators to remove the catalysts, treat them, regenerate them, and then bring in specialist contractors to reload the columns. The catalysts should be treated with care as health problems can result from their improper use. Table 4.1 outlines the toxicological data for the major substances in the system. This is for use in the event of exposure for whatever reason. Under ideal operating conditions, exposure should never occur with the exception of the regeneration process for the catalysts. Even then, it is recommended to use outside professionals when the catalysts require servicing to minimize potential contact with them.
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Table 4.1 – Toxicology for Process Chemicals Toxicology for Process Chemicals OSHA PEL ACGIH TLV LC50 (rat oral /vapor) [ppm] [ppm] [ppm/2 hour]) 8 hours Sodium Carbonatea N/A N/A 2300 Ruthenium on Carbon (5%)b 3.5 3.5 N/A Cobalt/Molybdenum 15 0.02 2000 on Aluminum Oxidec Methaned N/A 1000 500000 Carbon Dioxidee 5000 5000 326 Ammoniaf 50 25 7338-11590 ppm (1hour) a Sodium Carbonate MSDS b Ruthenium MSDS c Cobalt/Molybdenum MSDS d Methane MSDS e Carbon Dioxide MSDS f Ammonia MSDS
Tables 4.2 and 4.3 below explain the exposure effects caused by various forms of contact with the chemicals as well as the appropriate responses for each exposure method. The hazards and responses are given only for small exposures (less than 50 lg). Exposures of higher concentrations or contact times should refer directly to the MSDSs for more information. The MSDSs for the catalysts often did not have much information on the exact catalyst (ie ruthenium on on carbon at 5% versus normal ruthenium). In these cases, the best information known at this time is provided with the expectation that studies will continue to fill in any gaps in the knowledge. In the case of the molybdenum and cobalt on aluminum oxide, most of the data came from the normal cobalt MSDS since it is the most dangerous of the compounds to humans. Proper PPE must be worn if the catalysts are to be handled in any way.
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Table 4.2 – Exposure Effects of Process Chemicals Exposure Effects Contact Method Skin Eyes Ingestion Inhalation Sodium Carbonate Causes skin Causes eye irritation. May cause irritation of the digestive Harmful if inhaled. May cause respiratory irritation. May Lachrymator. tract. May be harmful if swallowed. tract irritation. be harmful if absorbed through the skin. Ruthenium on May cause skin May cause eye The toxicological properties of this May cause respiratory tract irritation. Carbon (5%) irritation. irritation. substance have not been fully investigated. May be harmful if swallowed.
Cobalt/Molybdenum May cause Causes eye irritation Cause effects on the heart after a May cause sensitization by inhalation and irritating on Aluminum Oxide contact short-term exposure. to the nose. dermatitis in cobalt sensitive individuals. Methane No harmful No harmful effects N/A Exposure to oxygen-deficient atmospheres effects (less than 19.5 %) may produce dizziness, nausea, vomiting, loss of consciousness, and death.
Carbon Dioxide No harmful No harmful effects N/A Carbon dioxide gas is an asphyxiant with effects effects due to lack of oxygen. It is also physiologically active, affecting circulation and breathing.
Ammonia Vapor contact Exposure to ammonia Ingestion is not a likely route of Ammonia is severely irritating to nose, throat, and may cause can cause moderate exposure for ammonia. lungs. Symptoms may include burning sensations, irritation and to severe eye coughing, wheezing, shortness of breath, headache burns. irritation. and nausea.
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Table 4.3 - Table Exposure Responses for Process Chemicals Exposure Responses Contact Method Skin Eyes Ingestion Inhalation Sodium Carbonate In case of contact, Check for and remove any Do NOT induce If inhaled, remove to fresh air. If immediately flush skin with contact lenses. In case of vomiting unless not breathing, give artificial plenty of water. Cover the contact, immediately flush directed to do so respiration. If breathing is irritated skin with an eyes with plenty of water for by medical difficult, give oxygen. Get emollient. Remove at least 15 minutes. Cold personnel. Never medical attention. contaminated clothing and water may be used. Get give anything by shoes. medical attention mouth. Ruthenium on Get medical aid. Flush skin Flush eyes with plenty of Get medical aid. Remove from exposure and Carbon (5%) with plenty of water for at water for at least 15 minutes, Wash mouth out move to fresh air immediately. If least 15 minutes while occasionally lifting the upper with water. not breathing, give artificial removing contaminated and lower eyelids. Get respiration. If breathing is clothing and shoes. medical aid. difficult, give oxygen. Get medical aid. Cobalt/Molybdenum Wash skin with water and Flush eyes with water Move to fresh air Do not induce vomiting. Give on Aluminum Oxide soap. nothing by mouth. Methane No treatment necessary No treatment necessary N/A Remove person to fresh air. If not breathing, administer CPR. If breathing is difficult, administer oxygen. Obtain prompt medical attention. Carbon Dioxide No treatment necessary No treatment necessary N/A Immediately remove to fresh air. If not breathing, give CPR. Ammonia Flush affected area with large Flush eyes with large Ingestion is not a Remove person to fresh air. If quantities of water. Remove quantities of water. Seek likely route of not breathing, administer contaminated clothing medical attention exposure for artificial respiration. If breathing immediately. If liquid comes immediately. ammonia. is difficult, administer oxygen. in contact with skin, remove Obtain prompt medical contaminated clothing and attention. flush with plenty of lukewarm water for several minutes
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4.2 Environmental Impact Statement One of the major goals for the plant is to design an environmentally friendly algae and sunlight as the central materials. A gate-to-grave life cycle assessment (LCA) was performed for the plant to identify potential environmental impacts caused by the raw material usage, production, and waste disposal for the whole factory. This LCA will discuss several different aspects of environmental impact including global warming potential (GWP), atmospheric lifetime (ATL), ozone depletion potential (ODP), and the regulation, disposal, and other environmental considerations for each of the process chemicals. First, the carbon balance in the system looks into the amount of carbon dioxide produced and released from the plant’s operations. Since the algae requires carbon dioxide in order to grow, the growth stages take in flue gas from another nearby plant and sequesters it inside of the algal biomass through photosynthesis. As the biomass is processed, some of the carbon is converted into oil that is sold to be burned in vehicles later. This oil holds these carbon atoms until it is consumed later, making the overall carbon balance be positive. The rest is put through CHG and eventually burned and recycled into the system. Since this recycled gas and the flue gas from the neighboring plant would have been expelled anyways, the plant actually helps to put these waste streams to use. The only carbon negative aspect of the plant comes from operating the vehicles that move pumps from one raceway system to another. Based on this, the plant is essentially carbon neutral and environmentally friendly in this manner. Table 4.4 shows the GWP, ATL, and ODP for the gases that could be present in the system. While the carbon dioxide is present in many areas of the plant, the methane is both produced and consumed within the plant without any release to the environment. Therefore, the methane’s GWP and ATL numbers are not applicable to the plant. A similar situation occurs for the ammonia. Since the ammonia actually exists as ammonium ions that are dissolved in the growth media, any effects on the atmosphere are nullified.
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Table 4.4
GWP (100 yr) ATL ODP
Methane 21 12+-3 yrs 0
Carbon dioxide 1 50-200 yrs 0
Ammonia 0 24 hours 0
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Table 4.5 Environmental Considerations of Process Chemicals H2O Solubility Vapor Regulations Degradation Disposal Method Pressure Byproducts Sodium Carbonate 71 g/L (0 °C), N/A Whatever cannot be saved for N/A Can be disposed of safely 215 g/L (20 °C), recovery or recycling should be and legally in the normal 455 g/L (100 °C) managed in an appropriate and trash if not contaminated approved waste disposal facility. Ruthenium on N/A N/A 1, Keep container in a well-ventilated N/A Vacuum or sweep up Carbon 5% place. 2, Keep away from sources of material and place into an ignition. 3, Do not empty into drains. ignition. Use a spark-proof 4, Take precautionary measures tool. Suitable disposal against static discharges. container. Cobalt/Molybdenum N/A N/A 1, Keep minimum amount of N/A Vacuum or sweep up on Aluminum Oxide chemicals on site (<100kg). 2, Keep material and place into an container in a well ventilated place. ignition. Use a spark-proof tool. Suitable disposal container. Methane 3.3 mL Permanent Safe in normal condition N/A Residual product in the gas/100mL system may be burned if a suitable burning unit (flair incinerator) is available on site. Carbon dioxide 0.9 vol/vol Permanent Safe in normal condition N/A Do not attempt to dispose of residual or unused quantities. Return cylinder to supplier. Ammonia 0.848 vol/vol Permanent Do not keep more than 45 Kg in the N/A Small amounts of Ammonia plant may be disposed of by discharge into water. The subsequent solution of ammonium hydroxide can be neutralized and should be properly disposed of in accordance with regulations. 1
Table 4.5 details the environmental procedures for disposing of both the gases and catalysts present in the system. It can be seen that there are no harmful degradation byproducts from any of the products which is expected from the catalysts. Since the catalysts will be regenerated and reused for many years, the disposal of these compounds will be a very rare occurrence without any significant environmental impacts. The most difficult product to deal with is the collected solids out of the precipitation tank (TK-301). Since these are primarily sulfates and phosphates, the solids could be converted back into fertilizers by selling them to fertilizer plants. This would improve the environmental sustainability by recycling these compounds as well. Another way to improve the environmental impact of the plant is to improve the energy balance. This is minimized in this plant by the production of methane from residual biomass. The methane is burned in a combustion reactor (R-304) and eventually used in a generator (G-201) to produce electricity. The facility can be entirely run off of this electricity with additional amounts that can be sold to the grid. This drastically improves the environmental impact of the plant by providing a renewable source of electricity. Table 4.6 offers insight into how to deal with an accidental release of any chemicals into the environment. In the case of the catalysts, an environmental release is also proof of an equally serious problem with the reactors which would demand immediate attention. Special interest should be taken to keep the growth media from infecting groundwater in a substantial amount. The effects that such an exposure would have on a human could be permanently damaging and should be avoided at all costs. Some of the chemicals used in the process are not only harmful to humans, but to the environment, the plants, and animals. Therefore, special considerations must be made when handling these chemicals. When the chemicals in the process are accidentally released to the environment, the right course of action must be taken to ensure that the chemical does not spread any further as outlined in Table 4.6. The first thing to do when there is a spill is to isolate the area and make sure people stay clear of the contaminant. If any of the gases is accidentally release to the atmosphere, the first precaution that must be taken is to ensure that no one breathes in the contaminated air by removing personnel from the affected area.
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Table 4.6 Accidental Release Measures Use appropriate tools to put the spilled solid in a convenient waste disposal container. If necessary: Neutralize the residue with a dilute solution of acetic Sodium Carbonate acid. 1, remove all ignition sources; 2,Clean up all the spills immediately with Ruthenium on protective equipment; 3, prevent dust cloud; 4, with clean shovel place Carbon (5%) material into clean, dry container and cover loosely 1, remove all ignition sources; 2,Clean up all the spills immediately with Cobalt/Molybdenum protective equipment; 3, with clean shovel place material into clean, dry on Aluminum Oxide container and cover loosely Evacuate immediate area. Eliminate any possible sources of ignition, and provide maximum explosion-proof ventilation. Use a flammable gas meter Methane (explosimeter) calibrated for methane to monitor concentration. 1, Carbon dioxide is an asphyxiant. Lack of oxygen can kill. Evacuate all personnel from danger area. 2, Use self-contained breathing apparatus where needed. 3, Shut off leak if you can do so without risk. 4, Ventilate area or move cylinder to a well-ventilated area. 5, Test for sufficient oxygen, especially in Carbon Dioxide confined spaces, before allowing reentry. Evacuate immediate area. Eliminate any possible sources of ignition, and provide maximum explosion-proof ventilation. Shut off source of leak if Ammonia possible. Isolate any leaking cylinder.
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5. Economic Analysis
5.1 Base Case Economic Analysis The main purpose of this project is to produce an economically feasible and environmentally renewable liquid transportation fuel. In order to start up this algal oil plant, a total capital investment of the project is introduced based on equipment costs and utility consumption. As per the design, an electric generator (G-201) can provide all of the required electricity through the utilization of waster heat from the combustion of methane. There are still allocated costs for energy though because of transportation fuel consumption. The water consumption cost is minimal compared to total equipment cost, which is over $119 million, (Table 5.1) and the total capital investment which is calculated at approximately $275 million. The total capital investment is directly affected by the total bare module cost. The initial investment amount requested in this project is extremely high due to the immaturity of technologies being scaled up. One positive comes from the location chosen to build the design. Since the algae will benefit from humid climates and large periods of sunlight, Florida was chosen as a build site. The accompanying site adjustment factor on the total investment is then 1.00 due to Florida being in the Gulf Coast area. In Table 5.2, the cost of manufacture is calculated with the main cost coming from the equipment maintenance part. This is due to the enormous cost of equipment though the equipment sizing has been optimized thoroughly throughout the calculations. Therefore, the final total capital investment to start up this algae plant is just under $275 million.
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Table 5.1 - Summary of Total Capital Investment Total Capital Investment Total Bare Module Cost for Onsite Equipment and Storage and Tanks $116,835,380.01 Total Bare Module Cost for Spare $2,380,006.75 Total Initial Cost for Feed $0.00 Total Bare Module Investment (TBM) $119,215,386.76 Cost of Buildings $11,921,538.68 Cost of Site Preparation $11,921,538.68 Cost of Service Facilities $26,445,815.55 Allocated Costs for Utility Plants and Related Facilities $2,602,738.20 Total Direct Permanent Investment $169,504,279.67 Contingencies and Contractors Fees $30,510,770.34 Total Depreciable Capital (TDC) $200,015,050.01 Cost of Land $40,003,010.00 Cost of Royalties $4,000,301.00 Cost of Plant Startup $20,001,505.00 Total Permanent Investment $264,019,866.01 Adjusted Total Permanent Investment $264,019,866.01 Working Capital $10,790,535.49 Total Capital Investment $274,810,401.50
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Table 5.2 - Summary of Cost of Manufacture COM $36,394,589 Feedstocks Catalyst $3,940,162
Utilities $18,411 Operations (Labor Related) $3,017,640 DW&B $2,184,000 DS&B $327,600 Operating Supplies and Services $131,040 Tech Assistance $180,000 Control Lab $195,000 Maintenance $16,101,212 MW&B $7,000,527 Salaries and Benefits $1,750,132 Materials and Services $7,000,527 Maintenance Overhead $350,026 Operating Overhead $2,567,795 Gen Plant Overhead $799,620 Mech Department Services $270,294 Employee Relations $664,473 Business Services $833,407 Taxes $4,000,301 Depreciation $6,749,068 Direct Plant $6,564,794 Allocated Plant $184,274
The net present value with a thirty-year-life cycle can be evaluated using the total capital investment and the sale price of the final products which are the heavy sweet crude oil and the electricity. In Table 5.4, the null net present value for a thirty-year-life cycle is shown with a 40% tax rate and 15% linear inflation rate. The price of electricity has been fixed due to the stability of the market. The number of barrels of oil produced yearly has been determined initially and the primary variable is the price of each barrel of oil. This price greatly fluctuates and depends on the time period and major global issues. By using Microsoft Excel Solver Tool, the null price of oil is determined to be no less than $174 (Table 5.3) which relates to a net present value of $0 after thirty years. This calculated price is much highly than today’s current market price. Figure 5.1 shows the NPV (net present value) as a function of time for this case.
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Table 5.3 - Sales with Null NPV Value Sales Sales Product Amount/Year Price Total Earnings Oil (per barrel) 351659.453 $174 $61,088,874 Electricity 105731000.2 $0.17 $17,974,270
Total Earnings per Year: $79,063,144
Table 5.4 - Net Present Value with $174 Oil Price
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Figure 5.1 - Net Present Value vs. Time with $174 Oil Price NPV vs. time $0 0 5 10 15 20 25 30 35
($50,000,000)
($100,000,000)
NPV vs. time
($150,000,000) NPV (dollar) NPV
($200,000,000)
($250,000,000) time (yr)
In fact, the actual crude oil price on April 23, 2013 is $100.39 per barrel (Crude Oil). If the produced oil is sold at this price, the net present value for a thirty-year-life cycle will be approximately - $100 million. This means that the plant not economically feasible in today’s market place. If the plant operates properly with such a sale price for thirty years, the value of this whole plant is extremely negative. Therefore, the current crude oil price will quickly turn this algae plant obsolete. The plant will require additional innovations and cost deductions before the plant can be built.
5.2 Monte Carlo Simulation During the process of running the model and determining appropriate market information and determination of viability of the plant, there were issues with sensitivity of variables in the process. Small changes to market information and prices of equipment yielded large changes in the thirty year overall net NPV. Not all process variables are known with enough certainty to be confident with forecasting these variables over thirty years. Forecasting these variables with some certainty in their value can prove to be inaccurate and misleading. One way to solve this is to run a Monte Carlo simulation on variables that are questioned as sensitive and variables that have the potential of large variations throughout the lifetime of the plant to see the overall outcome that changing these variables has on the overall outcome of the plant.
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It was determined that the variables that are most sensitive to this process and/or that have the highest likelihood of large variation throughout the lifetime are price of oil, price of electricity, generation efficiency, HTLE yield, and amount of algae generated in growth. Price of oil and price of electricity are large markets that have hard to predict trends and it is unwise to forecast prices of the long term (Short-term). Forecasted process variables were either found or estimated based on known data and entered as a normal distribution with the most likely outcome listed in Table 5.5 along with the standard deviation of the variable.
Table 5.5 – Values for Monte Carlo Simulation Variable Mean Standard Deviation Price of Oil ($/barrel)a 100 12.5 Price of Electricity ($/kWh)b 0.12 0.025 Generator Efficiency c 0.5 0.075 HTLE Yieldd 0.45 0.05 Algae Yield 1 0.0625 a Short-term, Ivan Kolesnikov, Crude Oil b Theodore Kury c What is, P.L. Spath, and M.K. Maan, Katherine Tweed d Brown et al.
These variables were entered into the as a random normal distribution model and run to find a thirty year NPV (20% tax rate) for 9943 trials to reduce the sampling error in the simulation. The output of frequency versus final thirty year NPV (20% tax rate) is shown in Figure 5.2. The average NPV for the simulation is -45.8 million dollars with a standard deviation of 28.2 million dollars. The average NPV gives the indication that the most likely outcome is a negative net NPV over the course of the project. The net NPV simulation yielded values between -101.1 million and 9.6 million dollars under 95% of the simulations. This means that under these realistic scenarios, there can be swing in net NPV of over 110 million dollars.
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Figure 5.2 – NPV Distribution for Monte Carlo Simulation Monte Carlo Distribution NPV 800
700
600
500
400
Frequency 300
200
100
0
5
5
-
95 85 75 65 55 45 35 25 15
15 25 35 45 55 65
------
175 165 155 145 135 125 115 105
------More Total 30 year NPV (40% tax in millions of dollars)
The large variations in NPV show that there cannot be a certain outcome as to the overall viability of the plant. The simulations that were run show that the most likely outcome of the process is still a net negative NPV and that there are approximately 5% of the simulations that have the positive NPV. This suggests that unless there are tax incentives, tax credits, or meaningful and substantial decreases in costs or increases in sales, there will be a negative outcome to running the process at this time.
5.3 Economic Hazards The following possible economic hazards are considered to evaluate the potential of the plant design. The actual sale price of oil in the Gulf Coast is approximately $100 which is significantly less than the null price of $174. The crisis is not solvable because of bottlenecks in the algae plant design. Since the technologies at play are still relatively new, additional research needs to be completed to improve the competitiveness of the plant. Along with this, a gigantic startup cost restricts the possibility of deductive sale price. Zero profit or even negative profit will be made using the current design. This is a fatal economic crisis that ends the feasibility of this plant economically. Moreover, any other equipment
7
or process failures within the plant could cause much higher downtimes than in other plants due the size, weight, and pressures of the system. Equipment failure will cause massive increases in operating costs and large backloads of product to be stored onsite or even wasted. The enormous initial investment is not proportional to the profit and is over risking. The investment risk of this plant is particularly high with a payback period far in the future that cannot be guaranteed. Overall, there hardly exists a competitive superiority of algal oil to conventional oil over pricing, feasibility and productivity. If the major factors described in the Monte Carlo simulation could be improved to their better values, the plant could one day become a feasible and sustainable option. The main value of this plant is the sustainability aspect. The design allows for the production of oil continuously with few inputs through the system. The consumption of conventional petroleum is extraordinary large in today’s world but the availability of fossil fuels is limited and finite. As these fossil fuels continue to dry out, algal oil will become an adequate substitute for conventional petroleum. Plus, the bottleneck of techniques and enormous cost of equipments will be potentially resolved due to passage of time. For now though, the only method is to increase the price even though it reduces competitiveness compared to conventional petroleum in order to reduce risk taking.
8
6. Conclusions and Recommendations
6.1 Conclusions A process of growing algae and extraction using filtration, HTLE, and CHG is done to maximize potential profits of growing algae on a commercial scale. Optimization is done to utilize recycling in as many areas of the process to increase sustainability of the overall process. NPV for the process over a thirty year lifespan with 40% tax rate is -$98.9 million when the oil is sold at approximately $100 per barrel. Monte Carlo simulation is done to show the large variation in likely outcomes of the total NPV for the process. A span of NPV’s was shown with a span over $110 million for 95% of the simulations, showing uncertainty in many process variables. Oil price, electricity price, HTLE yield, generator efficiency, and algae yield should be forecasted more accurately to give a better projection of viability of the process. Under the current conditions, the plant is not economically feasible unless certain tax incentives or tax credits are enough to overcome the current NPV deficit. According to the Monte Carlo simulations, only 5% of trials produced a positive NPV for a 30 year lifetime. Although the process is sustainable in as many areas as possible, the large capital investment provided too much debt to overcome.
6.2 Recommendations There are a number of ways that the current project can be elaborated upon and expanded in order to better model reality as well as to potentially optimize the system more. Some areas exist where the design can be expanded to include more aspects and compounds that are present while other areas would require experimental data in order to support some of the more drastic assumptions included within the design. In other places, the design could be adapted or expanded to allow for potential modifications to the current design. These are especially relevant when considering incoming reactant sources and potential economic situations. To begin with, the current model could be improved through adding in more details where simplifications were made. The first location where this occurs is with the treatment of the media. For most of the model, the media is treated as only water. The other ingredients within the media could potentially have adverse effects on the catalysts and other aspects of the process, especially considering the effects that the supercritical water could have as well. It is known that the presence of sulfates and phosphates can “poison” catalysts like ruthenium by binding to the active sites on the metal, an effect
9
that can actually be amplified by the operating temperature and pressure of the water. A similar phenomenon could be seen by some of the compounds in the growth media such as the trace metals and halogens. Since little is known about these potential effects, testing would be required before scaling up the reactors completely. To help with this, it would be a useful endeavor to expand the current atom balance to include each atom and compound from within the media. This would also include adding salt into the mixture since a saline solution can help to control potential contaminations from foreign species in the growth chambers. Another balance could also be set up in conjunction to the atom balance to estimate the charge breakdown at various points in the process. The most important place for this would be in the precipitation tank (TK-301) where the precipitated solids are currently modeled only as phosphates, sulfates, and potassium ions. Since the positive charges of the potassium cannot sufficiently account for the negative charges of the phosphates and sulfates, calcium or other metal ions would be required to balance out all of the anions. This could give a much better understanding to the losses in the precipitation tank to improve the model overall. The other two key areas that could profit from the expansion of the model are the absolute beginning and end of the plant: the inoculate methodology and the final oil processing. In terms of the inoculation step in the process, an inoculation procedure would need to be devised in order to steadily grow and maintain the algae population in a laboratory setting to ensure that contamination is not possible prior to entering the raceways. This procedure would also have to be on a large enough scale to provide 10% of the necessary starting volume in the bathtub scale for each set of raceways. In addition to the inoculation method, the design could be improved by testing different types of algae to determine which might work best in the plant. The second section comes into play with the post- production treatment of the oil. According to the current model, the heavy sweet crude oil product out of hydrothermal liquefaction has too high of a nitrogen and oxygen concentration to be sold as is. This is the purpose behind the downstream processing in Room 400 of the process flow diagram. The additional modeling comes into play when getting rid of the substances that the excess oxygen and nitrogen are converted into. Currently, the separation process is relatively unpublished in the literature and would require further studies before it could be properly implemented into the model. These compounds would need to be removed prior to selling the actual product to oil processing companies. This step of the process could be both time-consuming and expensive depending on the difficulty and reliability of the separation procedures but exists as the last critical step in the process. In addition to these areas of further study, the model could be significantly improved through additional experimentation and studies. The most important area for this to occur is with regards to the
10
reactor modeling. The current model relies on literature results for HTLE, CHG, and denitrification and deoxygenation. These values and assumptions would not be good enough if an actual plant was made, meaning that the results would need to be tested thoroughly as the process is scaled up. These results would primarily regard the relationship between the conversion rates and the residence time for the fluid in each reactor. This means that by increasing the residence time of the reactor, the completion of the reaction should increase. Similarly, the residence could be lowered and still be effective, meaning that the cost of the reactors would be lower. Additional experimental results would be the only way to truly optimize these two parameters. The results could also be expanded to model the effects of various temperatures, pressures, and algal composition changes. These would be beneficial in optimizing the system as well to potentially improve the yields from the overall process. Another important area lies in the generator. Because of the effects that increased energy generation can have on the economics and the energy balance of the system, continued research and experimental data could serve to greatly increase the efficiency of the generator which in turn would yield far greater energy returns. Due to the growing desire for natural gas in the nation overall, this could be as simple as waiting another year or two as the efficiency studies are published in the literature itself. This could also lead to substantial variation in price which is why the generator system is not factored into the economic calculations. Other areas that could benefit from additional research are the evaporation rates out of the growth section and the growth modeling itself. Currently, the evaporation rate is based off of an estimation of 1 millimeter per day in height that is dependent only on the surface area of ponds. While this is a scientific estimate, this value could vary substantially based on further data about the build site itself. Also, it would be quite useful to have additional experimental data to support the growth data provided. While it is possible that the data could remain constant throughout the sizing up process, the specific growth rate is a critical factor in the model. If the rate does not remain constant in the large size of the system, experimental data of this scale would be required to ensure that adequate amounts of algae are being produced. In addition to modeling reality better, further work could be used to further optimize the system. First off is the improvement of several inlets into the system. The process could potentially intake wastewater to offset both the cost of fresh water and potentially even some of the incoming nutrient costs. On a similar note, the cost of new nutrients could be offset if the solids stream out of the precipitation tank could be directly converted back into fertilizers. While methods for performing the conversion are available, the economic profitability would need to be inspected in terms of both capital and operating costs. Understanding the potential concentration of the flue gas and utilizing it could
11
further improve the economic conditions present in the model by limiting or eliminating the cost of carbon dioxide and making the system essentially carbon neutral. Another key optimization could come from using multiple pumps whenever the pressure is being increased substantially. By using multiple pumps in series, it could lower the capital costs for the system by an appreciable amount. The last bit of further study comes from additional work in understanding the economic potential of the system. One idea is to produce methane as a product stream to sell in the marketplace. This could allow for an increased revenue stream yet the remaining heat requirement for all of the heat exchanger pairs would need to be purchased or provided from other sources. This could outweigh the potential bonuses associated with this model though. One other way to improve the economic outlook could be to look into finding government tax breaks and other programs that could be applied due to the renewable energy products of the plant as well as the carbon neutral or even carbon negative balance. This would allow the plant to keep more of its profits to balance out the high capital and operating costs.
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7. Nomenclature V - Volume
- Mass flow rate of component i
- Density of component i
- Diameter of equipment i
- Length of equipment i
- Ratio of length to diameter
- Time for process to happen
- Mass of reactor
- Final algae concentration in reactors
- Initial algae concentration in reactors - Algae growth rate or viscosity
- HTLE Yield percentage for component i
- Mass of component i in stream j
- % composition of component i in stream
- Moles of component i in stream j
- Molecular weight of component i
- Moles of k that go to chemical l (CHG calculations) - Change in enthalpy
- Heat capacity of component i P - Pressure
- Concentration of component j in stream i
- Diffusivity between component A and B
- Diffusion time
- Average molar flux
- Total energy of a stream
- Energy generated from a stream
- Generator efficiency
- Log mean temperature difference Q - Heat rate U - Overall Heat Transfer Coefficient A - Area
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8. References
ABO offering algae biofuel credit guidance. AlgaeIndustryMagazine. Mar. 2013. Web. 24 Apr. 2013.
Ammonia. Material Safety Data Sheets. No. 001003. AIRGAS Inc. Web. 24 Apr. 2013. (Ammonia MSDS).
Brown, Tylisha M., Peigao Duan, and Phillip E. Savage. "Hydrothermal Liquefaction and Gasification of Nannochloropsis Sp." Energy & Fuels 24.6 (2010): 3639-646. Print.
Carbon dioxide. Material Safety Data Sheets. No.001013. AIRGAS Inc. Web. 24 Apr. 2013. (Carbon dioxide MSDS).
Cobalt Molybdenum on Aluminum Oxide. Material Safety Data Sheets. No. 6199-09 Ocriterion Catalysts & Technologies. Web. 24 Apr. 2013. (Cobalt MSDS).
Crude Oil and Commodity Prices. Oil-Price. 24 Apr. Web. 24 Apr. 2013 (Crude Oil)
HiSupplier.Ecofine Filtration Product CO., LTD, n.d. Web. 24 Apr. 2013.
Ivan Kolesnikov. Crude Oil Prices: Long Term Forecast to 2025. Knoema. 2013. Web. 24 Apr. 2013.
Katherine Tweed. Siemens Claims World’s Most Efficient Gas Turbine. Greentechmedia, Nov. 2011. Web. 24 Apr. 2013.
Long Term Outlook: Crude Oil Prices to 2030. Natural Resources Canada. Oct. 2010. Web. 24 Apr. 2013.
Methane. Material Safety Data Sheets. No. 1070. Air Products and Chemicals, Inc. Web. 24 Apr. 2013. (Methane MSDS).
Ogden Kimberly.Chlorella Trace Metals and Media. n.p.,Fed. 2013. Microsoft Word file.
Ogden Kimberly. Fatty acids profile for Chlorella. n.p, Fed. 2013. Microsoft Word file.
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Oyler, J.R.. CHG Feedstocks: Calculation of Wet Waste Material Availability in USA and World. Genifuel Corporation, Internal Data Compilation, 2011-2012. Spreadsheet.
Petroleum. Wikipedia. Wikimedia Foundation, 22 Apr. 2013. Web. 24 Apr. 2013.
P. L. Spath, and M. K. Mann. Life Cycle Assessment of a Natural Gas Combined-Cycle Power Generation System. National Renewable Energy Laboratory, Sep. 2000. Web. 24 Apr. 2013.
Ruthenium on Carbon 5%. Material Safety Data Sheets. No.296264. Santa Cruze Biotechnology, Inc. Web. 24 Apr. 2013. (Ruthenium MSDS).
Randy Ryan. Personal interview. Interview by Paul Blowers. May 22, 2009
R. B. Bird, W. E. Stewart, and E. N. Lightfoot. Transport Phenomena. Revised 2nd Edition. John Wiley & Sons, Inc. December 2006. Print.
Seider et al. Product and Process Design Principles. Wiley, 2009. Print.
Silver, H. F., N. H. Wang, H. B. Jensen, and R. E. Poulson. "A Comparison of Shale Gas Oil Denitrification Reactions over Co-Mo an Ni-W Catalysts." Oil Shales and Tar Sands: A Bibliography (n.d.): 3028- 038. Print.
Short-term Energy and Summer Fuels Outlook. U.S. Energy Information Administration. 19 Apr. 2013. Web. Web. 24 Apr. 2013.
Sodium Carbonate. Material Safety Data Sheets. No. 497-19-8. Science Lab. Web. 24 Apr. 2013. (Sodium Carbonate MSDS).
Theodore Kury. Addressing the Level of Florida’s Electricity Prices. Public Utility Research Center. Sep. 2011. Web. 24 Apr. 2013.
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U.S. Landed Costs of Nigerian Bonny Light Crude Oil. U.S. Energy Information Administration. n.d. Web. 24 Apr. 2013.
What is the efficiency of different types of power plants? U.S. Energy Information Administration, Feb. 2013. Web. 24 Apr. 2013.
Zhang et al. Study of Hydrodeoxygenation of Bio-Oil from the Fast Pyrolysis of Biomass. Taylor & Francis, 2010. Print.
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Appendix A Process Calculations Appendix
All of the calculations for the plant are given in the master spreadsheet which was submitted to the appropriate dropbox. It should be noted that the references to the general calculations or master spreadsheet and forwarded to this appendix instead.
The equations listed correspond to numberings in the calculation print outs. Any variable listings along with explanation on subscripting can be found in the Nomenclature section of the report.
Calculating the inputs to HTLE
The first variable that is known is the amount of unprocessed oil that is required. The reason unprocessed oil was chosen instead of final oil product is due to the uncertainty in the amount of oil waste there will be after processing. It is therefore simpler to estimate the amount of unprocessed oil that is required and use that number. Given an HTLE operating temperature, an HTLE operating pressure can be found by finding a rounded up pressure (to the nearest bar) that will keep water at that temperature in the liquid phase. Once operating conditions for HTLE are found, an estimated HTLE yield can be found using normalized correlations (Brown et al.). From the oil yield, the amount of algae that needs to be grown can be found by:
Once the amount of algae required is known, the next variable that needs to be known is the amount of water that needs to be in the solution before HTLE. The HTLE paper used a solids concentration of approximately 25% (Brown et al.) and a solids ratio of 23.7% is used in the design. The reason for the solids percentage is because this amount of water will allow the solids percentage into CHG to be 15%, and as far as the process was concerned, this was a variable that was fixed.
Sizing of Reactors
For sizing all of the reactors, a few approximations and assumptions were made to estimate the size of the reactors. First off, all reactors were assumed to be PFRs or batch reactors with a given reaction time.
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The number of “runs” that a reactor can go through in a day, or put another way, amounts of reactor volume that pass through the reactor in a day is calculated by:
Another assumption that is made is the size of the volume. From Table 2.7, the reactor volumes were assumed to have a volume where all liquids are assumed to have the density of water and all masses are assumed to also have the same density of water. The methodology being that no chemicals in the process have a higher density than water, thus giving an overestimate of the reactor volume. An example would be a sample volume for the sulfur scrubber. The amount of biomass going into the reactor is 253600 kg/day and the amount of water is 825600 kg/day. The amount of total reactor volume required is:
The variable that is chosen for the reactors is the amount of reactors that is chosen. This decision will be talked about at the end of this section. Once the number of reactors is chosen, the volume of each individual reactor can be found.
A chosen variable is defined, the diameter ratio. The variable is able to be tweaked so that the lengths and diameters will fit within the range defined by (Seider et al.). The length of the reactor and diameter of the reactor can then be found:
The next step is the process is to estimate the weight of the reactor for cost estimation.
The design pressure for the process is estimated to be 10% higher than the actual pressure required to allow for leeway in the process from a safety perspective. The process thickness can then be defined by (Seider et al.):
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The weight of the reactor can then be found (Seider et al.):
As previously mentioned, the amount of each reactor is a variable that is defined in the model. The first consideration is choosing appropriate amounts of each reactor such that the weight, length, height, and volume fit in the range from Seider et al. Next, the amounts should be either equal for each type of reactor or chosen such that there is a logical flow that will allow for robustness of turning the PFD into a P&ID. Odd numbers of reactors will cause the process to require more equipment to allow for the accommodation of the uneven number of reactors.
The cost for the reactors can be found in the economic section of the report.
Algae Growth
For the growing process, growth reactors were chosen in both series and parallel to maximize growth. Four series growth reactor were chosen to reduce the complexity of the problem and then amount of reactors in parallel is variable solved for in the calculations.
We assumed for the process that we could buy or harvest low concentrations of algae to insert into our smallest setup. The input to each of the reactors is 0.2 g/L and a final concentration of 2.0 g/L. The growth of the algae is assumed to be exponential and the stationary phase and death phase are assumed to be minimized. From that, the time until cultivation can be found:
The total volume per day required is then:
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The total volume is the amount of total volume that all the raceway sized reactors needs to hold combined once the algae is harvested every day. The total number of raceway systems can then be found by:
The size of the raceway system was arbitrary based on design ranges in the literature. The amount of evaporative losses in the systems is assumed to be 1mm multiplied by the surface area of the reactor. These evaporative losses will need to be added to the overall mass balance and accounted for later. The sizes and ratios of the Midsize, Bathtub, and Small Scale systems are based on a dilution ratio of 10 and using the same length to width ratio as in the raceway system. The chosen sizes and amounts are listed in Table 2.1. The amount of growth media that is required for each system is:
Where is the algae and media from the one step smaller scaled system. A schematic of the growth process is listed in Figure 2.2.
Determining Bio-oil concentration
Data from HTLE paper is normalized to determine total % of each element that is removed from the algae (carbon, hydrogen, oxygen, nitrogen, and sulfur). When the operating conditions are chosen, total mass of each element is chosen by using the chlorella elemental composition.
Where is mass of element i in the algae, is the percent total mass of element i that goes to biomass, and is the mass of element i in the unrefined bio-oil. The composition of the resulting unrefined bio-oil can be found with:
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Where N is the number elements that are being account for in the model. The resulting composition will be compared later against crude oils from fossil fuels to determine where refinement needs to take place.
CHG Atom Balance
After the amounts of each element that are converted to unrefined bio-oil then the residual biomass can be determined by:
The residual biomass is converted to a mole basis for CHG calculations:
The resulting products from CHG are done by balancing each element with their products that use that element. The first element balanced is carbon. From the CHG model used (Oyler, J.R.) there is a 50/50 split by mass in methane and carbon dioxide. This converts to 73.33% by moles in methane.
The leftover carbon is then given to carbon dioxide and the oxygen is distributed.
The next element to balance is nitrogen. This is done by taking all nitrogen in the residual biomass and converting it to ammonia:
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The left over oxygen and hydrogen is first balanced with water, and then with oxygen or hydrogen depending which element water does not balance. In our case, when water balances hydrogen.
And then the rest of the oxygen is converted to oxygen.
The products from HG will be separated into a vapor phase and a liquid phase. The CHG model (Oyler, J.R.) describes that 40% of the carbon dioxide by moles is saturated in the water. What results is that the liquid phase contains water, ammonia, and 40% of the carbon dioxide. The vapor phase contains the rest of the carbon dioxide, the methane, and the oxygen.
Combustion Temperature
The gaseous phase out of CHG is sent to a combustor to burn the methane so that the heat can be used to heat streams and then be converted to electricity to reduce the outside power demands. The amount of air that enters the combustor is determined by finding the stoichiometric amount of oxygen needed to burn all the methane, then:
To find the output temperature in the combustion unit, a thermodynamic cycle is implemented and then energy out is balanced with energy in and energy released by combustion:
The integral was done by inputing CP as a third order polynomial and doing a definite integral with the fit of heat capacity. Next, the final temperature is varied until the balance of energy equals 0. The resulting product stream is:
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Refining Bio-oil
The bio-oil refinement needed is deoxygenation and denitrification. Two papers were found hat describe a process for hydrodeoxygenation and hydrodenitrification using a catalyzed reaction at high temperatures and pressures (Zhang et. al, Silver et al.). The compositions from the Determining Bio-oil concentrations section are input.
This is done for both nitrogen and oxygen and the unnormalized concentration of both carbon and nitrogen is the same. The concentrations are then normalized around 100%. The resulting refined bio-oil composition is compared to reference values and industry standards to determine quality.
Carbon Dioxide Diffusion
Diffusion of carbon dioxide bubbles from flue gas is needed to determine the actual amount of carbon dioxide that is needed to have complete nutrient uptake. The carbon dioxide bubbles are assumed to be perfect spheres with 14 percent by mole carbon dioxide. The rest is assumed to be just a general flue gas that takes up the rest of the mass. The initial concentration of carbon dioxide in the bubble is:
The bubble velocity is assumed to begin terminal and is described by:
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The amount of time is second that the bubble is diffusing is the amount of time that is takes for the bubble to reach the top of the column:
The diffusion constant for this process can be approximated by (R. B. Bird, W. E. Stewart, and E. N. Lightfoot).
After the diffusivity is found, the % carbon dioxide that is diffused into the system is:
After the % carbon dioxide that is absorbed is found, the amount of total carbon dioxide that needs to be entered is:
The input of carbon dioxide comes from two inputs. The first is the carbon dioxide from the output of the generator, and the rest will be supplied from the flue gas.
The rest of the mass of flue gas is assumed to be 15% carbon dioxide by moles. The mass is assumed to be some generic flue gas stream with unknown components.
Electricity Generation
The amount of electricity generated from the plant is determined to be some factor of the total stream energy that is contained in the methane stream. The total stream energy is:
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After this energy is calculated, it is then converted into MW for ease of use. The actual power that can be extracted from the stream into electricity does not equal the amount of energy in the stream. This is due to the efficiency of the turbines not being 100%. To find the actual amount of power extracted:
After the amount of power generated is found, the net amount of power that is either supplied to or taken from the power grid can be calculated.
Heat Exchangers
The amount of heat that needs to be added is the same as Es. For each of the two streams in the heat exchanger, a Q can be found:
Once the heats are added together, the outlet temperature of the unknown stream is changed until the heats equal each other. Once the heats equal each other, the log mean temperature is found:
After the log mean temperature is found, the overall heat transfer coefficient can be estimated using Seider et al. Once that is estimated the area of the heat exchanger (which is important for sizing) can be found:
Important costing calculations for heat exchangers can be found in Appendix B.
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Appendix B Economic Calculations Appendix
These tables are not labeled since they are not directly reference in the body of the report. Each table reflects direct calculations from the spreadsheet. Bare Module Costs
Fans
Fiberglass Tanks
Reactors
26
Filters
Heat Exchangers
Total Capital Investment Total Bare Module Cost for Onsite Equipment and Storage and Tanks $116,835,380.01 Total Bare Module Cost for Spare $2,380,006.75 Total Initial Cost for Feed $0.00 Total Bare Module Investment (TBM) $119,215,386.76 Cost of Buildings $11,921,538.68 Cost of Site Preparation $11,921,538.68 Cost of Service Facilities $26,445,815.55 Allocated Costs for Utility Plants and Related Facilities $2,602,738.20 Total Direct Permanent Investment $169,504,279.67 Contingencies and Contractors Fees $30,510,770.34 Total Depreciable Capital (TDC) $200,015,050.01 Cost of Land $40,003,010.00 Cost of Royalties $4,000,301.00 Cost of Plant Startup $20,001,505.00 Total Permanent Investment $264,019,866.01 Adjusted Total Permanent Investment $264,019,866.01 Working Capital $10,790,535.49 Total Capital Investment $274,810,401.50
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Costs for Utlities Utilities Price total usage (gal/kW*hr) Total 18411.1774 Water 0.000075 245482366 18411.1774
Electricity (Supply more than consume) 0.17 -105731000.2 0
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COM $36,394,589 Feedstocks Catalyst $3,940,162
Utilities $18,411 Operations (Labor Related) $3,017,640 DW&B $2,184,000 DS&B $327,600 Operating Supplies and Services $131,040 Tech Assistance $180,000 Control Lab $195,000 Maintenance $16,101,212 MW&B $7,000,527 Salaries and Benefits $1,750,132 Materials and Services $7,000,527 Maintenance Overhead $350,026 Operating Overhead $2,567,795 Gen Plant Overhead $799,620 Mech Department Services $270,294 Employee Relations $664,473 Business Services $833,407 Taxes $4,000,301 Depreciation $6,749,068 Direct Plant $6,564,794 Allocated Plant $184,274
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Sales Sales Product Amount/Year Price Total Earnings Oil (per barrel) 351659.453 $174 $61,088,874 Electricity 105731000.2 $0.17 $17,974,270
Total Earnings per Year: $79,063,144
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31
32
Appendix C Monte Carlo Code
Monte Carlo VBA Scripts
Script for running the simulation:
Script for running the simulation up to 10000 runs:
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Appendix D Project Assumptions
General Process Assumptions: 1.) Algal biodiesel can adequately compare to fossil fuel crude oil and is similar in quality and chemical makeup. 2.) Biodiesel can be characterized by its percent composition of fatty acids rather than the individual molecular structures or lengths. 3.) The oil/media separation is possible and can be completed in sedimentation tanks (TK-302) during a given residence time. 4.) All of the reactors (HTLE, CHG, Denitrification and Deoxygenation) all scale linearly from lab or midscale results up to a large scale. 5.) HTLE affects Chlorella sp. similarly to how it treats Nannochloropsis. 6.) The efficiency of the combustion is 100% meaning that all of methane is burned away. 7.) The combustion is achieved using the exact stoichiometric amount of oxygen needed. 8.) The deoxygenation data scales appropriately regardless of which algae species is used. 9.) Denitrification works similarly for both fossil fuel and algae biodiesel. 10.) The product oil can be sold as heavy sweet crude oil without removing the byproducts of denitrification and deoxygenation process. Growth: 11.) The algal growth rate is constant and permanent in each of the raceways. 12.) Evaporation out of the raceways can be modeled based only on surface area at a rate of 1mm per square meter per day.
13.) The media flowing through the raceways mixes enough to allow for even diffusion of the CO2 ideal gas. 14.) The sparger can form flue gas bubbles that are perfect spheres with fixed diameter despite diffusion rates.
15.) The flue gas composition is 14% CO2 on a molar basis and the other components of the flue gas are safe to be pushed through the algae growth environments. 16.) The paddlewheel speed is high enough for appropriate mixing of the media to occur. 17.) There are no biomass losses to contamination in the system due to the salinity of the growth media. 18.) There is a perfect uptake of nutrients into the biomass from the media.
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Pumps: 19.) The raceway paddlewheels are modeled as small pumps with a correction factor due to the small horsepower requirements. Reactors/Tanks: 20.) Some cooling will occur from 35°C to 25°C during the wait times/tank residence times after CHG and HTLE. 21.) Each reactor is priced as horizontal pressure vessel which provides a realistic model. 22.) The catalyst prices for everything but ruthenium is negligible compared to the ruthenium itself. 23.) The solids content in CHG and HTLE is constantly controlled and will not affect the scale up of reactors and other pieces of equipment. 24.) No water vapor is present in the vapor exit stream from the phase separation tanks (TK-303 and TK-201). 25.) The precipitation tank (TK-301) and sulfur scrubber (R-301) can effectively remove all sulfates and phosphates from the biomass. 26.) The vapor output from CHG reactor (R-303) is a 60:40 split of methane and CO2 gas by mass. 27.) HTLE is able to break down the algae’s cell walls to allow all product oils to be extracted from within the algal biomass. Filters: 28.) The efficiency of the filter (F-201) is essentially 100% since the pore size is drastically less than the average diameter of the algae (0.036<<5). 29.) Using four filters in series results in 100% of the required filtration and dewatering. 30.) A minimal lateral pressure drop across the filter (5 bar) is allowed and a maximum transmembrane pressure drop of 0.2 bar can be adequately maintained. Economic Outlook: 31.) Oil projections can accurately model the actual prices in the global marketplace over the next 30 years. 32.) The utility prices throughout the plant are set and do not change with time. 33.) The plant is built close to a free, essentially unlimited source of flue gas that can provide carbon dioxide for the growth.
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Appendix E Overall Mass Balance
1
Appendix F Growth Media Chemical Makeup
BG-11 liquid growth media will be scaled up and produced in M-201.
BG-11 Liquid Growth Media
Generation Directions: 1.) Starting with approximately 900 mL of ultra pure water (UPW), add the first 9 components in the order specified while stirring continuously. 2.) Bring the total volume to 1 L with UPW. 3.) Cover and autoclave the media. 4.) Allow to cool and then store at refrigerator temperature.
# Component Amount Stock Solution Final Concentration Concentration
1 NaNO3 10 mL/L 30 g/200 mL UPW 17.6 mM 2 K2HPO4 10 mL/L 0.8 g/200 mL UPW 0.22 mM 3 MgSO4*7H2O 10 mL/L 1.5 g/200 mL UPW 0.03 mM 4 CaCl2*2H2O 10 mL/L 0.72 g/200 mL UPW 0.2 mM 5 Citric Acid*H2O 10 mL/L 0.12 g/200 mL UPW 0.03 mM 6 Ammonium Ferric Citrate 10 mL/L 0.12 g/200 mL UPW 0.02 mM
7 Na2EDTA*2H2O 10 mL/L 0.02 g/200 mL UPW 0.002 mM 8 Na2CO3 10 mL/L 0.4 g/200 mL UPW 0.18 mM 9 BG-11 Trace Metals 1 mL/L 0.4 g/200 mL UPW 0.18 mM 10 Sodium Thiosulfate 24.8 g/100 1 mM Pentahydrate mL
Alternative calculations for components:
For citric acid (C6H8O7) instead of citric acid*H2O
Citric Acid MW =192.13 g/mol Citric Acid*H2O MW =210.14 g/mol
BG-11 Trace Metal Solution
Generation Directions: 1.) Starting with approximately 900 mL of UPW, add the components in the order specified while stirring continuously.
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2.) Bring the total volume to 1 L with UPW. 3.) Store at refrigerator temperature.
# Component Amount Final Concentration 1 H3BO3 2.86 g/L 46 μM 2 MnCl2*4H2O 1.81 g/L 9 μM 3 ZnSO4*7H2O 0.22 g/L 0.77 μM 4 Na2MoO4*2H2O 0.39 g/L 1.6 μM 5 CuSO4*5H2O 0.079 g/L 0.3 μM 6 Co(NO3)2*6H2O 49.4 mg/L 0.17 μM
It should be noted that the content will remain the same while the directions would have to change when producing the media on a large scale. For instance, the storage and autoclaving would probably not happen since the media is continuously used by the system. Salt would also be added in a slight quantity to help stave off potential contamination.
It should also be noted that the current design in Appendix A uses a more generic media to simplify the model. The model must be upgraded to find the exact nutrient recycling capabilities and input mass flow rates.
*All of the above information was provided from (Ogden, Ogden 2).
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Appendix G Chlorella sp. Fatty Acid Profile and Key Growth Parameters
Below is the standard fatty acid profile for the Chlorella species when grown in the media described in Appendix F. The fatty acids are described as percentages of the total fatty acid content.
Table G.1 - Fatty acids profile for Chlorella C14:0 0.50%
C16:0 23.16%
C16:1n9 5.48%
C16:2n7 10.41% c16:3n7 5.15%
C18:0 1.41%
C18:1n9 11.84%
C18:2n9 26.51%
C18:3n9 7.09%
Sum 91.53%
The following two parameters are also given for the species under the operating conditions:
Fatty Acid Content: 25%
Chlorella Specific Growth Rate: 0.013 hr-1
*All of the above information was provided by (Ogden, Ogden 1).
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Appendix H Meeting Minutes It should be noted that meeting minutes were not always taken when meeting with Dr. Blowers or were lost throughout the semester.
Meeting Minutes Form
Date ____January 22nd 2013______Planned Meeting Start Time ____11:10am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:10am 12:15pm Michael Cordon 11:10am 12:15pm Tyler List 11:10am 12:15pm Zijun li 11:15am 12:15pm
Group Member 1 ______Aaron______Progress: Aaron is working on the growth of the algae. He is focusing on collecting the data for fresh water algae for the starting unit of the process. For example, the nutrient needed for algae, the temperature of the location match with the algae or not, and life cycle growth rate of the algae.
New Task: Aaron’s goal for next week is figuring out at least two different filters that can be used for a prime dewatering process. According to the Hydrothermal liquefaction part’s feedback, he can pick the filter and set up the model for the algae growth.
Group Member 2 _____ Tyler______Progress: Tyler is focusing on the Hydrothermal liquefaction part of the process. Right now, he is filling in “Basis of Design” and collecting the information for Hydrothermal liquefaction part of the process.
New Task: Tyler is going to focus on the basic condition and parameters which will be used in the whole process, set up the standard letter for each variable to help us work on our only section while we can keep everything is consistent.
Group Member 3 ______Michael______Progress:
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Michael is on duty of catalytic hydrothermal gasification part of the process. Right now he is writing an introduction draft for the meeting with Dr. Blowers on January 23rd, describing the duty for each unit that group members should work on.
New Task: Michael is going to prepare the questions for the meeting with Dr. Blowers for liquefaction process and start to work on the calculation of catalytic hydrothermal gasification part of the process. Group Member 4 ______Zijun______Progress: Zijun is charging on the separation part of the process. And right now, he is making the first draft of the gantt chart for the team, then everyone in the team will revise the gentt chat to make a final draft.
New Task: Zijun is going to do some research on the separation section and try to make a series of steps to do the separation part of the process. After getting feedback with some raw data from the HTLE section, he should refine the separation process and share the basic structure in next meeting.
Next Meeting Date____ January 23rd 2013______, Time ______1:30pm______, Place ___Dr. Blowers’ Office______
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Meeting Minutes Form
Date ______January 23rd 2013______Planned Meeting Start Time __ 1:30pm______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 1:30pm 2:05pm Michael Cordon 1:30pm 2:05pm Tyler List 1:30pm 2:05pm Zijun li 1:30pm 2:05pm Dr. Blowers 1:30pm 2:05pm
This meeting is basically getting some confirmations of some detail in each processing unit from Dr. Blowers and talk about the schedule and goal that Dr. Blowers set for the team. Location will be somewhere in the southeast of mainland America. There are few ways to make the separation work if the mixture remains the same condition as the HTLE section. We have to drop the temperature and pressure after HTLE section before the fluid goes in to separation. The team will going to develop a heat exchanging process in the second stage of the calculation to save energy for rising the temperature and pressure for CHG part after the separation process. We will have the introduction part of the report done before the next meeting with Dr. Blowers and we should aim on finishing the report one week before the final week.
** The individual processing and the goals for next week won’t change since this meeting is a day after the group formal meeting and we need time to do the research and work on the goals which are set for next week’s meeting.
Next Meeting Date_____January 29, 2013_____, Time ___11:10am______, Place ______Room 10______
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Meeting Minutes Form
Date _____2/5/2013______Planned Meeting Start Time ______11:15______
Name (Include mentors etc.) Time Arrived Time Left Michael Cordon 11:10 Tyler List 11:00 Zijun Li 11:05 Aaron Zhang 11:00
Provide a brief summary (2 to 4 sentences or bullets on Each Individuals Progress. Include what the individual is working on, what is expected by the next meeting)
Group Member 1 Zijun Li Progress: Don’t need membrane separation anymore
New Task: Need to find glycerol amount needed per batch
Group Member 2 Tyler List Progress: Developed BFD model with Michael Cordon and did a balance around all atoms in the process.
New Task: Work on stream table compilation and how to size the HTLE reactors for bare module costing.
Group Member 3 Aaron Zhang Progress: Filter specifics and can set water mass content
New Task: Look into nutrient types, cultivation methods, is the way we are doing filtration right. Find more sources for filtration.
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Group Member 4 Michael Cordon Progress Preliminary PFD completed, CHG modeling started
New Task Finalize intro, work on modeling CHG, and assist in writing up the equipment table
Next Meeting Date______, Time ______, Place ______
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Meeting Minutes Form
Date ____February 12 _____ Planned Meeting Start Time ____11:00am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:00am 12:00pm Michael Cordon 11:00am 12:00pm Tyler List 11:00am 12:00pm Zijun li 11:00am 11:50pm
Group Member 1 ______Aaron______Progress: Figured out the nutrient types from Dr. Blowers’ paper
New Task: Start collect the information to start the safe section.
Group Member 2 _____ Tyler______Progress: Worked on the stream table
New Task: Start to do the calculation for HTLE
Group Member 3 ______Michael______Progress: Finalized intro and modeling CHG
New Task: Do the Preliminary calculation for the heat exchanger with Zijun.
Group Member 4 ______Zijun______Progress: Calculated glycerol amount needed per batch New Task: Do the Preliminary calculation for the heat exchanger with Michael.
Next Meeting Date____ Fed 19th 2013______, Time ______11:00am______, Place ___Student Union______
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Meeting Minutes Form
Date ____February 19th _____ Planned Meeting Start Time ____11:00am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:00am 12:00pm Michael Cordon 11:00am 12:00pm Tyler List 11:00am 12:00pm Zijun li 11:00am 12:00pm
Group Member 1: Aaron Progress: Started to work on LCA and environmental table
New Task: Do the lab safety audit with group and continue work on his part of the process.
Group Member 2: Tyler Progress: Worked on the calculation for HTLE
New Task: Do the lab safety audit with group and continue work on his part of the process.
Group Member 3: Michael Progress: Finished the heat exchanger network
New Task: Will work on the mass balance with Zijun and do the lab safety audit with group
Group Member 4: Zijun Progress: Finished the heat exchanger network New Task: Will work on the mass balance with Micheal and do the lab safety audit with group
Next Meeting Date____ February 26th 2013______, Time ______11:00am______, Place ___Student Union______
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Meeting Minutes Form
Date ____Februray 26th 2013______Planned Meeting Start Time ____11:10am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:10am 12:15pm Michael Cordon 11:10am 12:15pm Tyler List 11:10am 12:15pm Zijun li 11:15am 12:15pm
Group Member 1 ______Aaron______Progress: Finished the writing for lab safety audit.
New Task: Finalize both the safe and environmental tables
Group Member 2 _____ Tyler______Progress: Finished the calculation for HTLE
New Task: Start the calculation for denitrification.
Group Member 3 ______Michael______Progress: Finished the mass balance
New Task: Work on the raceways for the growth tanks.
Group Member 4 ______Zijun______Progress: Finished the mass balance.
New Task: Start to do the calculation for the electricity generator in the project.
Next Meeting Date____ January 23rd 2013______, Time ______1:30pm______, Place ___Dr. Blowers’ Office______
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Meeting Minutes Form
Date ____March 5th _____ Planned Meeting Start Time ____11:00am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:00am 12:00pm Michael Cordon 11:00am 12:00pm Tyler List 11:00am 12:00pm Zijun li 11:00am 12:00pm
Group Member 1 ______Aaron______Progress: Helped Zijun to set up the eco section and worked on the safety issue for the project.
New Task: Start to write up the safety section
Group Member 2 _____ Tyler______Progress: Finished the calculation for denitrification.
New Task: Finish the master spreadsheet.
Group Member 3 ______Michael______Progress: Worked on the raceways for the growth tanks.
New Task: Help Tyler for the size reactor parameters
Group Member 4 ______Zijun______Progress: Finalized the calculation for electricity generator.
New Task: Start to do the economic calculations.
Next Meeting Date____ March 19 2013______, Time ______11:00am______, Place ___Student Union______
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Meeting Minutes Form
Date ______3-19-13______Planned Meeting Start Time ______11:00______
Name (Include mentors etc.) Time Arrived Time Left Michael Cordon 11:00 11:35 Tyler List 11:00 11:35 Zijun Li 10:55 11:35 Aaron Zhang 11:00 11:35
Provide a brief summary (2 to 4 sentences or bullets on Each Individuals Progress. Include what the individual is working on, what is expected by the next meeting)
Group Member 1 ___Michael Cordon______Progress: Began revising PFD, helped size reactor parameters
New Task: Revise intro and process description, aid in the creation of stream tables and equipment tables that reflect PFD setup
Group Member 2 ____Tyler List______Progress: Completed master spreadsheet calculations
New Task: Create stream tables and equipment tables
Group Member 3 ____Zijun Li______Progress: Began work on rough economic calculations
New Task: Finish generic economic calculations for input of actual results and calculations
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Group Member 4 _____Aaron Zhang______Progress Worked on safety and environmental tables and started write up
New Task Finish write up and tables, write out filter sizing parameters for use in equipment table
Next Meeting Date_____4-2-13_____, Time _____11:00, Place _Student Union____ Individual to contact any missing group members via email/phone – copy Dr. Ogden Michael Cordon__
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Meeting Minutes Form
Date ______3-26-13______Planned Meeting Start Time ______11:00______
Name (Include mentors etc.) Time Arrived Time Left Michael Cordon 11:00 11:35 Tyler List 11:00 11:35 Zijun Li 10:55 11:35 Aaron Zhang 11:00 11:35
Provide a brief summary (2 to 4 sentences or bullets on Each Individuals Progress. Include what the individual is working on, what is expected by the next meeting)
Group Member 1 ___Michael Cordon______Progress: Editing intro, finalized PFD setup, helped complete equipment calculations and stream table
New Task: Writing new process description, equipment description and rationale, PFD auxiliary effects
Group Member 2 ____Tyler List______Progress: Finalized equipment table, stream tables, etc.
New Task: Begin drafting calculations and assumptions appendices
Group Member 3 ____Zijun Li______Progress: Finished economic outline calculations and utility tables
New Task: Upload official calculation results into model and begin economic calculations write up
Group Member 4 _____Aaron Zhang______Progress Completed safety/environmental tables for new compounds New Task Finish drafting safety/environmental sections, write out filter specifications
Next Meeting Date_____4-2-13_____, Time _____11:00, Place _Student Union____ Individual to contact any missing group members via email/phone – copy Dr. Ogden Michael Cordon__
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Meeting Minutes Form
Date ____April 9th _____ Planned Meeting Start Time ____11:00am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:00am 12:00pm Michael Cordon 11:00am 12:00pm Tyler List 11:00am 12:00pm Zijun li 11:00am 12:00pm
Group Member 1 ______Aaron______Progress: Finish the preliminary Safety and environmental section
New Task: Work on the reference section
Group Member 2 _____ Tyler______Progress: Finalized the stream table and equipment table, etc
New Task: Work on the process description.
Group Member 3 ______Michael______Progress: Refined the modeling for CHG and HTLE, and PFD auxiliary effects
New Task: Work on the process description.
Group Member 4 ______Zijun______Progress: Finalizing on the eco section in excel and made the outline for the eco writing
New Task: Work on the eco section writing.
Next Meeting Date____ April 16th 2013______, Time ______11:00am______, Place ___Student Union______
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Meeting Minutes Form
Date ____April 16th _____ Planned Meeting Start Time ____11:00am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:00am 12:00pm Michael Cordon 11:00am 12:00pm Tyler List 11:00am 12:00pm Zijun li 11:00am 12:00pm
Group Member 1 ______Aaron______Progress: Worked on the reference section.
New Task: Start to edit the report.
Group Member 2 _____ Tyler______Progress: Worked on the process description with Michael and also writing the calculations appendix.
New Task: Start to edit the report.
Group Member 3 ______Michael______Progress: Worked on the process description with Tyler.
New Task: Start to edit the report.
Group Member 4 ______Zijun______Progress: Worked on the Eco section with Tyler to finalize and last minute numbers. Writing the econ section.
New Task: Finish econ section and edit section.
Next Meeting Date____ April 23rd 2013______, Time ______11:00am______, Place ___Student Union______
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Meeting Minutes Form
Date ____April 23rd _____ Planned Meeting Start Time ____11:00am______
Name (Include mentors etc.) Time Arrived Time Left Aaron Zhang 11:00am 12:00pm Michael Cordon 11:00am 12:00pm Tyler List 11:00am 12:00pm Zijun li 11:00am 12:00pm
Group Member 1 ______Aaron______Progress: Editing the report
New Task: Edit the report, and add references to the report.
Group Member 2 _____ Tyler______Progress: Editing the report
New Task: Check Michael’s writing section.
Group Member 3 ______Michael______Progress: Editing the report
New Task: Check Zijun’s writing section.
Group Member 4 ______Zijun______Progress: Editing the report
New Task: Check Aaron’s section.
Next Meeting Date____ April 29th 2013______, Time ______11:00am______, Place ___Student Union______
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