University of Pennsylvania ScholarlyCommons Department of Chemical & Biomolecular Senior Design Reports (CBE) Engineering 4-2013 Natural Gas to BTX Daniel Consoli University of Pennsylvania Nima Jelveh University of Pennsylvania Hardik Kotecha University of Pennsylvania Sulim Lee University of Pennsylvania Follow this and additional works at: https://repository.upenn.edu/cbe_sdr Part of the Biochemical and Biomolecular Engineering Commons Consoli, Daniel; Jelveh, Nima; Kotecha, Hardik; and Lee, Sulim, "Natural Gas to BTX" (2013). Senior Design Reports (CBE). 50. https://repository.upenn.edu/cbe_sdr/50 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/cbe_sdr/50 For more information, please contact [email protected]. Natural Gas to BTX Abstract A plant that uses three major stages to convert natural gas to produce a 1MMM lb of mixed xylenes stream a year, which contains 68 wt% of para-xylene, was designed for this project. The three main stages are the dehydrocyclization stage, where methane is converted to benzene; the alkylation stage, where benzene is alkylated to form xylenes; and the post- processing stage that separates para-xylene from the mixed xylene stream. The goal of the project was to produce a billion pounds of BTX while maximizing profits. This eporr t provides a detailed design and economic analysis for the production of para- xylene and mixed xylenes on the Gulf Coast. Process flow sheets, energy and utility requirements, and equipment summaries have been provided and analyzed. The process is currently unprofitable with an IRR of 5.77% and a net present value of $(327,000,000) at a discount rate of 20%. The financials for this venture are highly sensitive to the price of natural gas, which is currently $0.02/lb. A few major reasons that make this venture unprofitable are the extremely high costs for the two proprietary processes, namely the Sulfolane process and the Parex process, high use of utilities, and low conversion of methane to benzene. After in depth analysis of the financials, we ecommendr that this project should not be executed unless the proprietary process costs are significantly reduced or a better conversion of methane to benzene is achieved. Disciplines Biochemical and Biomolecular Engineering | Chemical Engineering | Engineering This working paper is available at ScholarlyCommons: https://repository.upenn.edu/cbe_sdr/50 Department of Chemical & Biomolecular Engineering Senior Design Reports (CBE) University of Pennsylvania May 2013 Natural Gas to BTX Daniel Consoli Nima Jelveh University of Pennsylvania University of Pennsylvania Sulim Lee Hardik Kotecha University of Pennsylvania University of Pennsylvania CBE 459: PROCESS SYSTEM DESIGN PROJECTS Professors Leonard Fabiano and Warren Seider Natural Gas to BTX Senior Design Project Daniel Consoli, Nima Jelveh, Hardik Kotecha, Sulim Lee 04/09/2013 Department of Chemical and Biomolecular Engineering University of Pennsylvania Faculty Advisor: Dr. Wen Shieh, University of Pennsylvania Project Author: Mr. Bruce Vrana, DuPont Engineering Research & Technology University of Pennsylvania School of Engineering and Applied Science Chemical and Biomolecular Engineering April 9th 2013 Dear Dr. Shieh, Mr. Fabiano, and Mr. Vrana, As requested in our assigned Senior Design Project Statement, we have designed and evaluated a process for the production of benzene, tolune, and xylene products (BTX) from natural gas. This process produces one billion pounds of BTX as was specified in the project request. A process producing xylenes was pursued as the only product of this process because its production was the only one that was calculated to be profitable on a material balance basis given the patented process pursued. In spite of the limited information available on many of the proprietary technologies needed to optimally run this process, we are confident in the accuracy of the costs, energy requirements, and feasibility judgments that are presented in this report regarding the production of BTX from natural gas. This process provides a detailed process and the potential profitability of the proposed BTX plant. The design incorporates a natural gas feed rate of 315,800 lb/hr and methanol feed rate of 112,000 lb/hr. Production was assumed to operate 24 hours a day for 330 days a year. The main fixed capital investments for this process are the proprietary Parex unit, two multi- stage compressors, a proprietary sulfolane unit, and two very large heat exchanger units. Based on the provided pricing of BTX components, reagents, and side products, the proposed process yields an IRR of 5.77%. This modest return is below the hurdle rate of 20% and therefore it is not recommended that this process be pursued. This process could be further improved via enhanced separation processes that would greatly reduce the cost of utilities required. In addition, further research into the implementation of other proprietary processes would allow additional optimization to be achieved. Sincerely, ______________ ______________ ______________ ______________ Daniel Consoli Nima Jelveh Hardik Kotecha Sulim Lee Table of Contents Table of Contents Natural Gas to BTX ........................................................................................................................ 2 ABSTRACT ................................................................................................................................ 9 I) INTRODUCTION ..................................................................................................................... 10 Project Charter .......................................................................................................................... 10 Process Overview...................................................................................................................... 11 II) MARKET AND COMPETITIVE ANALYSES ..................................................................... 15 Market Analysis ........................................................................................................................ 15 The Use of Natural Gas Over Oil ......................................................................................... 15 Benzene ................................................................................................................................. 16 Xylene ................................................................................................................................... 17 BTX Industry ........................................................................................................................ 18 Competitive Analysis ................................................................................................................ 20 Competition........................................................................................................................... 20 Porter’s Five Forces: ............................................................................................................. 21 Customer Requirements ............................................................................................................ 24 III) PROCESS OVERVIEW, FLOWSHEETS, MASS BALANCE & ENERGY BALANCE... 27 Preliminary Process Synthesis .................................................................................................. 27 Assembly of Database............................................................................................................... 41 Bench-Scale Laboratory Work ................................................................................................. 42 Process Flowsheet and Material Balances ................................................................................ 44 Process Description ................................................................................................................... 55 Energy Balance and Utility Requirements ................................................................................ 67 Utilities:................................................................................................................................. 68 Heat Integration Alternatives: ............................................................................................... 70 Heat Exchanger Network (HEN) Flowsheet ............................................................................. 83 IV) EQUIPMENT LIST, UNIT DESCRIPTIONS, AND SPECIFICATION SHEETS ............. 91 Equipment List and Unit Descriptions ...................................................................................... 91 Distillation Columns ............................................................................................................. 91 Decanter ................................................................................................................................ 94 Reactors................................................................................................................................. 94 Compressors .......................................................................................................................... 95 Pumps .................................................................................................................................... 97 Heat Exchangers ................................................................................................................. 101 Fired Heaters (Furnaces) ....................................................................................................