THE ASSESSMENT of SYNGAS UTILIZATION by FISCHER TROPSCH SYNTHESIS in the SLURRY–BED REACTOR USING Co/Sio2 CATALYST 1. INTRODUC

THE ASSESSMENT OF SYNGAS UTILIZATION BY FISCHER TROPSCH SYNTHESIS IN THE SLURRY–BED REACTOR USING Co/SiO2 CATALYST

Bambang Suwondo Rahardjo Technology Center for Energy Resources Development Deputy for Information, Energy and Material of Technology Agency for the Assessment and Application of Technology (BPP Teknologi) BPPT II Building 22ndFl, Jl. M.H. Thamrin No. 8 Jakarta 10340 Email: [email protected]

ABSTRACT

Syngas or synthetic gas is a gas mixture containing CO, CO2 and H2 followed by compound SOx, NOx and CH4 in a lesser amount of each gas is different depending on feed material, gasifying agent and gasification process. Syngas can be produced from coal or biomass gasification process at high temperature conditions with the amount of air / oxygen / steam injection as a controlled gasifying agent. Syngas can be used as intermediate products to produce other chemicals or burned as an energy source to drive gas engine. In this research discusses the use of syngas from gasification proceeds through the Fischer-Tropsch Synthesis process as a substitute for synthetic liquid fuel. The results from the 10 run–times conducted mostly produces gaseous hydrocarbon (HC) light C1~C2 (CH4, C2H6) SNG equivalent except RUN–02. Gaseous hydrocarbons (HC) light C1~C3 (CH4, C2H6, C3H8) is produced by RUN–01, RUN–05, RUN–07, RUN–10 (where RUN–03 is relatively small). While RUN–05, RUN–07, RUN–10 are capable of producing hydrocarbon gases (HC) light C1~C4 (CH4, C2H6, C3H8, n-C4H10 i-C4H10) LPG equivalent. The other 4 run–times (RUN–04, RUN–06, RUN–08, RUN–09) less so produce the desired product. Product hydrocarbon gases (HC) light C1~C4 are the largest produced by the RUN–05 with N2 gas content is relatively small, in contrast with the RUN–01, RUN–07, RUN–10 less desirable in the Fischer-Tropsch Synthesis process since the content of N2 gas is still relatively high. Product hydrocarbon gases (HC) light C1~C3 is the smallest produced by RUN–01 compared to RUN–05, RUN–07, RUN–10, however, indicated to produce HC chain C > C5 ~C12 (oil), this means that the smaller the resulting gas products have a tendency to produce more oil. Liquid product produced by RUN–01, RUN–05, RUN–07, RUN–10 have indicated tendency of products HC chain C > C5~C12 (oil) which is relatively very small quantity and quality can not be known for sure (equivalent prediction kerosene), since the current vacuum distillation process (P = 10 mmHg using a solvent reagent C16H34) were bumping.

Keywords : syngas, CoSiO2 catalyst, hexadecane solvent, slurry–bed reactor, F/T synthesis

1. INTRODUCTION gasoline is technology Gas-To-Liquid (GTL), which Indonesia as a country endowed with rich variety of consists of (a) via gasification syngas generation natural resources is time start 'glance' coal or biomass technology [Coal-To-Gas (CTG) or Biomass-to-Gas to be processed either as a source of energy and other (BTG)] and (b) Fischer-Tropsch Synthesis (FTS). industrial raw materials so as to reduce the 'servings' of petroleum. Fischer-Tropsch Synthesis (FTS) is the process of converting syngas (CO + H2) which form a long Considered one of the most effective ways to chain aliphatic compounds HC (CxHy) HC branched overcome the energy crisis is through the chain, unsaturated HC, and a small amount of development and utilization of alternative energy primary alcohol. FTS processes are developed using resources, such as coal or biomass to the fullest. One fixed-bed reactor can achieve high conversion and technology that can take advantage of the coal / capable of producing optimal parafinis HC class. biomass into synthetic liquid fuel replacement for System through cracking (cracking), the product can 20

be directed to produce gasoline and diesel fuel types HC indispensable as a fuel for motor vehicles. Technological developments GTL (Gas-To-Liquid) Fischer-Tropsch Synthesis process for converting in the world today has reached the commercial stage, syngas into synthetic liquid HC consists of 2 catalytic (such as Sasol Ltd.., Shell, ExxonMobil, Rentech reactions that form large molecules of HC from CO Inc.., Syntroleum Corp., JNOC, etc.) as the holder of and H2 molecules coal gasification process results / a patent has been successfully operate the GTL biomass with oxygen in the feed steam, in which the refineries in various parts of the world such as product is determined by the use of this kind of Nigeria, Egypt, Argentina, Qatar, Iran, Malaysia, and catalyst, H2/CO ratio and reactor operating Australia. conditions. Currently, the Fischer-Tropsch Synthesis process has . been operated commercially in Sasol - South Africa (coal), Shell in Malaysia (natural gas), ExxonMobil, The value of n is very dependent on the method of Rentech, and Syntroleum. Choren Industries has built making synthetic gas and the type of materials used, an Fischer–Tropsch plant in Germany that converts e.g. natural gas H2/CO ratio = 1.8~2.3, coal = biomass to syngas and fuels using the Shell Fischer– 0.6~0.8. Olefin-rich product with a range of 5 ~ 10 Tropsch process [6]. (naphtha) Fischer-Tropsch process results in high temperatures can be used to make synthetic gasoline In this study focused on the syngas utilization by and chemicals, contrary to the paraffin-rich product Fischer-Tropsch Synthesis using 1L range of 12 ~ 19 (distillat) results of Fischer-Tropsch autoclavemodified slurry-bed reactor with catalyst Synthesis process of low-temperature very suitable (Co/SiO2) and solvent hexadecane into synthetic for making synthetic diesel and / or wax. liquid fuels instead of fuel oil.

Figure 1. The alternative of syngas utilization as liquid fuel/synthetic gas and chemicals

natural-gas fields. The use of microchannel reactors 2. LITERATURE REVIEW scales down the size of the reaction hardware and overcomes the heat and mass transport problems associated with conventional FT technology. The Fischer–Tropsch process is a collection of Enhanced heat transfer inside the microchannels chemical reactions that converts a mixture of CO and reactor allows for optimal temperature control, which H2 into liquid hydrocarbons. It was first developed maximizes catalyst activity and life. While no smaller by Franz Fischer and Hans Tropsch at the "Kaiser- scale plant is currently in commercial operation, Wilhelm-Institut für Kohleforschung" in Mülhei an indications show capital costs, operating costs and der Ruhr (Germany) in 1925. size could all be reduced relative to conventional FT facilities [15][9]. An order has reportedly been placed The process, a key component of gas to liquids for a 1400-bbl/day modular GTL plant using the technology, produces a synthetic lubrication oil and technology of a company called Velocys [11]. synthetic fuel, typically from coal, natural gas, or biomass. The Fischer–Tropsch process has received In Australia, Linc Energy commenced construction in intermittent attention as a source of low-sulfur diesel 1999 of the world's first gas–liquid plant operating on fuel and to address the supply or cost of petroleum- synthesis gas produced by underground coal derived hydrocarbons. gasification . The GTL plant uses the F-T process, 2.1. Technology Developments and produced liquids in 2008. The largest scale implementation of Fischer–Tropsch technology are in Since the invention of the original process by Fischer a series of plants operated by Sasol in South Africa, a and Tropsch, working at the Kaiser-Wilhelm-Institut country with large coal reserves, but little oil. The for Chemistry in the 1920s, many refinements and first commercial plant opening in 1952, 40 miles adjustments have been made. Fischer and Tropsch south of Johannesburg [14]. Sasol uses coal and now filed a number of patents, e.g., U.S. Patent 1,746,464, natural gas as feedstocks and produces a variety of applied 1926, published 1930. It was commercialized synthetic petroleum products, including most of the by Brabag in Germany in 1936. Being petroleum- country's diesel fuel. poor but coal-rich, Germany used the Fischer– Tropsch process during World War II to In December, 2012 Sasol announced plans to build a produceersatz fuels. Fischer–Tropsch production 96,000 barrels a day plant in Westlake, Louisiana accounted for an estimated 9% of German war using natural gas from tight shale formations in production of fuels and 25% of the automobile fuel Louisiana and Texas as feedstock. Costs are [12]. estimated to be between 11 and 12 billion dollars with $2 billion in tax relief being contributed the state The Fischer–Tropsch process has been applied in of Louisiana. The planned complex will include a large-scale gas–liquids and coal–liquid facilities such refinery and a chemical plant [4]. as Shell's Pearl GTL facility in Ras Laffan, Qatar. Such large facilities are susceptible to high capital PetroSA, a South African company which, in a joint costs, high operation and maintenance costs, the venture, won project innovation of the year award at uncertain and volatile price of crude oil, and the Petroleum Economist Awards in 2008 has the environmental concerns. In particular, the use of world's largest Gas to Liquids complexes at Mossel natural gas as a feedstock becomes practical only Bay in South Africa. The refinery is a 36,000 barrels with use of "stranded gas", i.e., sources of natural gas a day plant that completed semi-commercial far from major cities which are impractical to exploit demonstration in 2011, paving the way to begin with conventional gas pipelines and LNG commercial preparation. The technology can be used technology; otherwise, the direct sale of natural gas to convert natural gas, biomass or coal into synthetic to consumers would become much more profitable. fuels [3]. Several companies are developing the process to enable practical exploitation of so-called stranded gas One of the largest implementations of Fischer– reserves. Tropsch technology is in Bintulu, Malaysia. This Shell facility converts natural gas into low-sulfur Conventional FT reactors have been optimized for Diesel fuels and food-grade wax. The scale is 12,000 massive coal-to-liquids and gas–liquid facilities such barrels per day (1,900 m3/d). The new LTFT facility as Shell's Pearl GTL facility. These slurry bed and Pearl GTL which began operation in 2011 at Ras fixed-bed reactors are much larger than the sizes Laffan, Qatar, uses cobalt catalysts at 230°C, needed for biofuel facilities or for smaller-scale converting natural gas to petroleum liquids at a rate 22

of 140,000 barrels per day (22,000 m3/d), with gasification. Located in Commerce City, Colorado, additional production of 120,000 barrels (19,000 m3) the facility produces about 10 barrels per day (1.6 of oil equivalent in natural gas liquidsand ethane. The m3/d) of fuels from natural gas. Commercial-scale first GTL plant in Ras Laffan was commissioned in facilities are planned for Rialto, California; Natchez, 2007 and is called Oryx GTL and has a capacity of Mississippi; Port St. Joe, Florida; and White River, 34 000 bbl/day. The plant utilizes the Sasol slurry Ontario [8]. Rentech closed down their pilot plant in phase distillate process which uses a cobalt catalyst. 2013, and does not appear to be continuing work on Oryx GTL is a joint venture between Qatar their FT process and the proposed commercial Petroleum and Sasol. facilities.

In October 2006, Finnish paper and pulp In the United States, some coal-producing states have manufacturer UPM announced its plans to produce invested in Fischer–Tropsch plants. In Pennsylvania, biodiesel by the Fischer–Tropsch process alongside Waste Management and Processors, Inc. was funded the manufacturing processes at its European paper by the state to implement Fischer–Tropsch and pulp plants, using waste biomass resulting from technology licensed from Shell and Sasol to convert paper and pulp manufacturing processes as source so-called waste coal (leftovers from the mining material [13]. process) into low-sulfur diesel fuel [1].

A demonstration-scale Fischer–Tropsch plant is owned and operated by Rentech, Inc., in partnership with ClearFuels, a company specializing in biomass Table 1. Process developer of Fischer– Table 2. Process development of Fischer–Tropsch Tropsch Synthesis commercial scale Synthesis commercial scale in the world Syngas React Capa Comp Cata Prepar or city Syngas FTS any lyst Countr Production ation FTS (bpd) O Producti (catalys y 2 Capacity Energy Slurry on t) PO (O2) – Co Int. –bed Tubular Slurry– 7 bpd JOGME not CPO Slurry Reformer bed Pilot Exxon 200 Co C nee (O2) –bed Rentec (O ), Slurry 2 235 Fe Sasol Auto Slurry– 17.000 bpd h SR, –bed (South Thermal bed Commercia nee ATR Africa) Reformer (Co) l (x2) d PO (O2), > SR, Slurry Fe, POX Fixed– 3.000 bpd Sasol 2.500 Shell Coal –bed Co nee Bed Commercia (Malays Gasifica d (Co) l (x4) ia) tion Fluidi 110.0 Auto Slurry– 200 bpd Shell PO (O ) zed– Co 2 00 Exxon Thermal bed Demonstrat bed nee Mobil Reformer (Co) ion Fixed d 12.50 (USA) Mobil> eum (air) Fixed 2 –bed Slurry– CPOX bed 400 bpd (C)PO : (Catalytic) Partial Oxidation, SR : Conoco nee

o> Compact Slurry– 300 bpd BP nee Reformer bed Demonstrat (USA) d (Co) ion

2.2Syngas Oxygen 0.6% 0.4% – Syngas (synthetic gas) as a raw material composed of (O2) a mixture of CO and H2 gas produced through Methane 3.0% 3.0% 90.0% gasification of biomass / coal and partial oxidation (CH4) process of natural gas. Syngas manufacturing process Nitrogen 50.9 48.6% 5.0% that has commercial is steam reforming, partial (N2) % oxidation and CO2 reforming. Ethane – – 5.0% (C2H6) Syngas produced from the biomass gasification has HHV 163 135 1,002 some impurities formed in the form of inorganic (Btu/scf) compounds, such as: NH3, HCl, and H2S, and small 1&3Steam - Its generation and use, Babcock amounts of COS, CS2, and HCN. and Wilcox, pp. 5-20 and 5-21 discussion of coal producer gas. Overall FTL system (Fischer Tropsch Liquid) except 2HMI International. Data derived from a the BTL system (Biomass To Liquid) is designed fixed–bed updraft gasifier design. using a Water-Gas Shift reaction that enough from syngas with the ratio H2/CO = 1:1 for the total amount of syngas entering the synthesis reactor FTL. While the BTL system using H2/CO ratio = 1.8 for syngas exit gasifier without WGS between gasifier and synthesis reactor [16]

Influence of impurities contained in the raw syngas, such as sulfur will poison the catalyst in the syngas preparation process at high temperature, sulfur will be converted to H2S or COS. How to cope with sulfur converted to H2S by adding CaCO3 into the gasifier or through high-temperature desulfurization process using ZnO. While COS (carbon oxysulfide) can be addressed through a hydrolysis process at low temperature (200oC) using zeolite / alumina that occurs interaction in molecular absorption of H2S and H2O, or can be by way of hydrogenation at a temperature of 750oC.

COS+H_2 O→H_2 S+〖CO〗_2 (exothermic reaction)

COS+H_2→H_2 S+CO (endothermic reaction)

Table 3. Syngas composition from coal and biomassa gasification, natural gas

Syngas Compositio Biomass Natur n Coal1 a2 al Gas3 Hydrogen 14.0 18.0% – (H2) % Carbon 27.0 Monoxide 24.0% – % (CO) Carbon Dioxide 4.5% 6.0% – (CO2)

Table 4. Requirements of syngas as feedstock Fischer-Tropsch Synthesis

Impurities Range

H2S + COS + CS2 < 1 ppmV

NH3 + HCN < 1 ppmV HCl + HBr + HF < 10 ppbV

Alkaly metal < 10 ppbV

Solids (soot, ash, dust) Essentially completely

Organic compounds (tar) < dew point

Hetero–atoms (Class 2) < 1 ppmV 2.3. Catalyst

A common catalyst used in the Fischer-Tropsch economical than the Cobalt but susceptible to catalyst Synthesis process is kind of a transition metal that is poisons such as sulfur (S). Cobalt (Co), Iron (Fe), Ruthenium (Ru) and Nickel (Ni), but the most commonly used is the Co and Fe Ni catalyst make CO hydrogenation to produce the called the Basic Metals. most of CH4 at high operating temperature conditions that led to the formation of volatile The Co catalysts is most active and very sensitive to carbonyls, thus making this metal is not attractive to the presence of sulfur compounds (S which is the Fischer-Tropsch Synthesis. poisonous, are able to produce wax. Co catalysts prepared for the usual raw materials derived from Ru catalyst capable for synthesizing a molecular natural gas with a high content of H2 so much higher weight of the paraffin over 200,000 at high pressure. H2/CO ratio so it does not require WGS, when the From an economic perspective, the use of Ru catalyst syngas feeding with a high H2 content so much is not very effective because it is much more higher H2/CO ratio. SiO2 as a buffer is more expensive than the Cobalt. dominant than TiO2 as well as Al2O3 (SiO2>TiO2>Al2O3).. Co catalyst at high pressure Selection of a catalyst based on the ability to will give effect to the high amount of carbon. Metal accelerate the reaction between some reaction Co as catalyst Fischer-Tropsch Synthesis process (selectivity), has a high activity and efficiency, ease [5].generally dispersed in the buffer material with a of regenerated, i.e. the process of restoring the large surface area (alumina, silica, titan, etc..) on activity and selectivity of catalysts as they are, and loading of 10 ~ 30 g per 100 g of buffer [10]. have chemical stability, thermal and mechanical that will determine the life of the catalyst. Fe catalyst will tend to form some chemical 2.4. Solvent compounds such as iron oxides and iron carbides Solvent function as dissolving in the process of during the reaction. Ferrous metals (Iron / Fe) purification products such as Fischer-Tropsch suitable to syngas with a low hydrogen content Synthesis in the form of slurry is distilled to obtain (H2/CO <1) prepared as lower quality feedstock for the other factions. Table 5 shows the general promoting WGS (water gas shift). Fe is more characteristics of the type of solvent used and marketed commercially.

Table 5. Characteristic of commercial solvents

Nonane Decane Undecane Dodecane Tridecane Tetradecane Pentadecane Hexadecane C H C H C H C H C H C H C H C H Formula 9 20 10 22 11 24 12 26 13 28 14 30 15 32 16 34 CAS number [111~84~2] [124~18~5] [1120~21~4] [112~40~3] [629~50~5] [629~59~4] [629~62~9] [544~76~3] Molar mass (g/mol) 128.26 142.29 156.31 170.34 184.37 198.39 212.42 226.45 Melting point (°C) −53 −30 −26 −9.6 −5 5.5 9.9 18 Boiling point (°C) 151 174 196 216.2 234 253 268~270 287 Density (g/ml) 0.718 0.73 0.74 0.75 0.763 0.769 0.773

Viscosity 20°C (cP) 0.711 0.92 1.35 2.18 3.34

Flash point (°C) 31 46 60 71 102 99 132 135 Autoignition 205 210 205 235 201 temp. (°C) Explosive limits (%) 0.9~2.9 0.8~2.6 0.45~6.5%

2.5. Reactors The reactor type of Fischer-Tropsch Synthesis 2.6. Process Condition consists of a slurry-bed, fixed-bed, and fluidized-bed operated over a temperature range of 150-300°C, Generally, the Fischer–Tropsch process is operated in pressure of 0.7-41 bar. the temperature range of 150–300°C. Higher • Three–Phase Fluidized–bed / Ebullating– temperatures lead to faster reactions and higher bed or Slurry Bubble Column equipped by internal conversion rates but also tend to favor methane cooling tubes, wax as support metal-oxides catalyst production. For this reason, the temperature is usually particles during the bubble syngas flows to the maintained at the low to middle part of the range. bottom of the reactor. Reaction temperature higher Increasing the pressure leads to higher conversion than the boiling point of the FT product called rates and also favors formation of long-chained exothermic reaction. Slurry as fever (heat sink) and alkanes, both of which are desirable. Typical the reactor temperature stabilizer, but because of the pressures range from one to several tens of interface between mineral oil slurry with metal-oxide atmospheres. Even higher pressures would be catalysts, HC formed soluble in the slurry phase, favorable, but the benefits may not justify the sucked out the catalyst so that the catalyst activity additional costs of high-pressure equipment, and increase, decrease oxidation of the catalyst, as well as higher pressures can lead to catalyst deactivation via stabilizing chain growth. It is cheaper to LTFT (Low coke formation. Temperature Fischer Tropsch). • Multitubular fixed–bed equipped with a A variety of synthesis-gas compositions can be used. cooler, consisting 1000 of a small tube with a catalyst For cobalt-based catalysts the optimal H2:CO ratio is as an active catalyst surface (surface active agent) in around 1.8–2.1. Iron-based catalysts promote the the tube, the water surrounding the tube to regulate water-gas-shift reaction and thus can tolerate lower the temperature by adjusting the steam pressure. ratios. This reactivity can be important for synthesis • Circulating fluidized–bed using a circulating gas derived from coal or biomass, which tend to have bed material, recycled gas and cooling gas / solids relatively low H2:CO ratios (<1). circulation used in LTFT. • Fluidized–bed equipped with a refrigerant used in HTFT (High Temperatur Fischer–Tropsch)

Table 6. Process condition of Fischer–Tropsch Synthesis by product

Suhu Tekanan H /CO Katalis Produk 2 (oC) (bar) Cu–Zn Ethanol 1,0~1,4 200~420 51,7~261,99 Cu–Co Campuran alkohol

MeOH Katalis 2,3 Cu–ZnO <250 51,7~261,99 Gasoline DME Zeolith Gasoline Syngas 2 Fe 340 23,44 Gasoline Wax Hydro– Diesel cracking Co–K 240 25,51 Diesel Wax

2.7. Reaction Mechanism that form C-C bonds, such as migratory insertion. Many related stoichiometric reactions have been The conversion of CO to alkanes involves simulated on discrete metal clusters, but hydrogenation of CO, the hydrogenolysis (cleavage homogeneous Fischer–Tropsch catalysts are poorly with H2) of C-O bonds, and the formation of C-C developed and of no commercial importance. bonds. Such reactions are assumed to proceed via initial formation of surface-bound metal carbonyls. The CO ligand is speculated to undergo dissociation, Product recovery depends on several factors, among possibly into oxide and carbide ligands [2]. others: the type of reactor, type of catalyst, the process parameters [temperature, pressure, residence Other potential intermediates are various C-1 time, H2/CO ratio, concentration of reactants (H2, fragments including formyl (CHO), hydroxycarbene CO, CO2, H2O)]. (HCOH), hydroxymethyl (CH2OH), methyl (CH3), methylene (CH2), methylidyne (CH), and hydroxymethylidyne (COH). Furthermore, and critical to the production of liquid fuels, are reactions

Main Reaction  Parafin (2n + 1)H2 + nCO → CnH2n+2 + nH2O  Olefin 2nH2 + nCO → CnH2n + nH2O  Water gas shift reaction CO + H2O → CO2 + H2

Side Reaction  Alkohol 2nH2 + nCO → CnH2n+2O + (n-1)H2O  Boudouard reaction 2CO → C + CO2

Catalyst Modification  Catalyst oxidation/reduction MxOy + yH2 → yH2O + xM MxOy + yCO → yCO2 + xM  Bulk Carbide Formation yC + xM → MxCy

2.8. Products

Table 7. Fischer–Tropsch Synthesis products

Number of Boiling Point Products Utility Carbon (°C) C ~ C SNG 1 2 0~50 Gas tube, Fuel gas, Petrochemicals C3 ~ C4 LPG

C5 ~ C10 Petroleum C5 ~ C7 Light 50~85 Fuel oil C8 ~ C10 Heavy C11 ~ C20 Middle Destillate C11 ~ C12 Kerosine 85~105 Fuel oil C13 ~ C20 Diesel C21 ~ C30 Softwax 105~135 Fuel oil, Industrial fuel C31 ~ C60 Hardwax 130~300 Lubricants, Wax, Petrochemicals, Asphalt

α = The chain growth probability or the HC light is methane (CH4), ethene (C2H4) and probability that a molecule will continue reacting to ethane (C2H6), LPG (C3–C4, propane and butane), form a longer chain. In general, α is largely gasoline (C5–C12), diesel fuel (C13–C22), dan wax determined by the catalyst and the specific process (C23–C33). conditions. • Product diesel: require hydrocracking liquid products Fischer–Tropsch Synthesis to break the Examination of the above equation reveals that double bond in the catalytic use H2. methane will always be the largest single product so • Petroleum refining products: products long as alpha is less than 0.5; however, by increasing Fischer–Tropsch Synthesis which has been α close to one, the total amount of methane formed completely cleaned of sulfur, nitrogen, nickel, can be minimized compared to the sum of all of the vanadium, and asphaltene aromatic. various long-chained products. Increasing α increases • Fischer–Tropsch diesel with high cetane the formation of long-chained hydrocarbons. number can be used as a blending component for improving the quality of diesel fuel. The very long-chained hydrocarbons are waxes, • Liquid products Fischer–Tropsch Synthesis which are solid at room temperature. Therefore, for is very suitable for fuel cell vehicles. production of liquid transportation fuels it may be necessary to crack some of the Fischer–Tropsch In general the product distribution of hydrocarbons products. In order to avoid this, some researchers formed during the Fischer–Tropsch process follows have proposed using zeolites or other catalyst an Anderson–Schulz–Flory (ASF) distribution [7] substrates with fixed sized pores that can restrict the which can be expressed by formula mentioned below formation of hydrocarbons longer than some and shown in Figure 4 and Figure 5. characteristic size (usually n<10). This way they can drive the reaction so as to minimize methane Wn = The weight fraction of hydrocarbon formation without producing lots of long-chained molecules containing n carbon atoms (%w). hydrocarbons. Such efforts have met with only limited success.

Distribution products of Fischer-Tropsch Synthesis chain olefin as a result of dissolving ability of HC in depends on several parameters, among others: syngas SCFs (super-Critical Fluids) high; overcome feed composition, catalyst type, temperature, deactivation of the catalyst through heat and mass pressure, alkali promoter, and buffer. Low transfer better; conditioning the extraction of heavier temperatures will influence the amount of carbon HC to come out of the catalyst pores so that it can (Carbon Number, CN) is high, but slightly branched extend the catalyst life; H2 increase transfer chain or low oxygenate compounds. capability into the catalyst pores to give more promoted reaction; and improve the main product 3. RESEARCH desorption from catalyst pores to avoid further reaction that will have an impact on product The assessment of syngas utilization by Fischer selectivity Tropsch Synthesis using CoSiO2 catalyst in the autoclave 1L modified slurry–bed reactor conducted 3.2. Equipments at the Coal Liquefaction Laboratory – PUSPIPTEK - Serpong. • Autoclave 1L ‘KOBELCO’ (Pmax = 29.42 3.1. Materials modified slurry–bed reactor to examine the reactivity • Mixed–gas (H2:60%, CO:30%, N2:10%) of the catalyst. with H2/CO ratio = 2:1 • GC–TCD: (Thermal Conductivity Detector) • Mixed–gas (H2:54%, CO:30%, CH4:10%, for the gas products analysis and HC C1~C3 N2:6%) with H2/CO ratio = 1.8:1 • GC–FID: Flame Ionized Detector for • Co/SiO2 catalyst made of Cobalt–based oxygenates product analysis and HC C2~C30 9.22%Co and Cobalt–based 31.08%Co3O4 from • Vacuum Distillator separation bottom Co(NO3)2.6H2O (Cobalt Nitrate) with 90.78%SiO2 product (slurry, HC berat, wax) (nature zeolith) and 68.92%SiO2 (Nacalai zeolith) • Furnace for catalyst reduction process respectively as buffer material. The catalysts made by • Vacuum Drying Oven for catalyst drying treatment as follows: process.

A. Catalyst : Nature zeolith, calcination (300oC, 2 hours), reduction (300oC, 1 hour) B. Catalyst : Nature zeolith without treatment C. Catalyst : Nacalai zeolith, calcination (300oC, 2 hours), reduction (300oC, 1 hour) D. Catalyst : Nacalai zeolith, calcination (200~400oC, 2 hours), reduction (400oC, 6 hours)

• Hexadecane (C16H34) chosen as the solvent with consideration of characteristics reduce the formation of CH4 leads to a more severe HC, evenly distributed heat in the reactor; generate more long-

Figure 6. Schematics of equipment system for Fischer-Tropsch Synthesis research scale

3.3. Metodology (XRD) to determine %crystallinity and successful Co metal impregnation on SiO2 as catalyst support by 3.3.1. Catalyst Preparation looking at the properties treatment effect and the origin crystal structure to changes in metal Co3O4 Catalyst preparation carried out due to the difficulty into CoO or Co. to obtain FTS catalysts are commercially produced, • The catalyst reactivity testing carried out by using the following steps: after Co/SiO2 catalyst prepared and characterized • Impregnation to deposit metallic Co from using specific content of Co and reacted with mixed- Co(NO3)2.6H2O (Co–Nitrat) into SiO2 as buffer gas inside autoclave 1L to investigate the through drying process in the vacuum dryer at performance of catalytic reaction that is measured in (100~110oC, 12 hours) in oder to H2O and HNO3 the amount of conversion and yield [conversion vaporized. mixed-gas (H2/CO) into compound HC]. • Calcination to remove the H2O content is still trapped in the the SiO2 crystal pores by heating 3.3.2. Fischer–Tropsch Synthesis at a temperature of 200~400oC (still below the melting point) for 2 hours, but in the furnace to The process of converting syngas into liquid HC expand the catalyst surface and stabilize heat catalyst. products via Fischer-Tropsch Synthesis occurs in the • Reduction to obtain Co metal in an active 1L autoclave modified slurry-bed reactor with the condition by bubbling H2 gas as a reductant inside process mechanism as shown in Figure 7. plug flow reactor made of stainless steel (ID = 2") at a temperature of 400oC for 6 hours. • Characterization performed after calcination and reduction using X-Ray diffraction spectrum

Figure 7. Fischer Tropsch Synthesis mechanism

• Flashing, by flowing N2 gas and mixed-gas • Identification of reaction products is done respectively 2 times at a pressure of 30 bar. "on-line" with the GC (steady-state for 10 hours), to • Leak test, by flowing mixed-gas at a separate the components of compound HC product, pressure of 5~6 MPa = 50~60 bar higher than reactor measure the quantity and quality of the components operating pressure during the contact time = 3 hours. in the eluent, to calculate the amount of product Whenever there is an indication of a leak pressure> conversion yield, analysis of liquid and gas products 20 bar. qualitatively. • Feeding, CoSiO2 catalyst (20 bar, 260- 3.3.3. Separation 300oC, 2 hours), C16H34 solvent (1 ml/min), and Gas products carried by flowing through the gas mixed gas (50 cm2/gr catalyst). outlet pressure regulating valve (trap). Heavy HC and

slurry products including wax done physically using • Mixed–gas (H2:60%, CO:30%, N2:10%) the media separator funnel. with H2/CO ratio = 2:1 for RUN–01, RUN–05, RUN–07, RUN–10. 3.3.4. Sampling • Mixed–gas (H2:54%, CO:30%, CH4:10%, Sampling of the product carried out after the room N2:6%) with H2/CO ratio = 1.8:1 for RUN–02, temperature is reached. Product gas through the gas RUN–03, RUN–04, RUN–06, RUN–08, RUN–09. outlet pressure regulating valve (trap). Liquid product • Catalysts based Co (9.22%Co) from (bottom products: slurry, heavy HC, wax) from the Co(NO3)2.6H2O with 90.78%SiO2 (nature zeolith) trap and distillation. as a catalyst support for RUN–02, RUN–03, RUN– 04, RUN–06, RUN–08, RUN–09. 3.3.5. Analysis • Catalysts based Co (31.08%Co3O4) from Gas products & HC C1 ~ C3 using GC-TCD. Co(NO3)2.6H2O with 68.92%SiO2 (SiO2 Nacalai) Oxygenates products and HC C2~C30 using GC- as a catalyst support for RUN–01, RUN–05, RUN– FID. Oil products using GC-FID-Pyrolizer. 07, RUN–10. • Hexadecane (C16H34) as a solvent for the 3.3.6. Purification whole RUN. Vacuum filtration of the liquid products (slurry, heavy HC including wax). Vacuum distillation of the 4.1. Result slurry product at a pressure of 10 mmHg using a solvent reagent Hexadecane (C16H34) with a boiling Product gas is generated each time the RUN analyzed point of 287°C, in order to obtain other fractions. using GC-TCD and GC-FID to determine the Made as wax products produced. composition and %volume of gas contained. 4.1.1. Gas Product 4. RESULT AND DISCUSSION Following the GC-TCD and GC-FID analysis results During the research has been done 10 times RUN of standard gas and gas products for-01 RUN, RUN- Synthesis Fischer-Tropch use Autoclave 1L modified 05,-07 RUN, RUN-10 were carried out in the slurry-bed reactor at operating conditions (P = 20 bar, Laboratory of Coal Liquefaction in PUSPIPTEK – T = 260~300oC, t = 2 hours, r = 900 rpm) with the Serpong. following feeding materials:

Figure 8. Profile of GC-TCD and GC-FID gas standards RUN-01

Figure 9. Profile of GC-TCD and GC-FID gas product RUN-0

Figure 10. Profile of GC-TCD gas standard RUN–05, RUN–07, RUN–10

Figure 11. Profile of GC–TCD and GC–FID product gas RUN–05

Figure 12. Profile of GC–TCD and GC–FID product gas RUN–07

Figure 13. Profile of GC–TCD and GC–FID product gas RUN–10

Table 8. Product gas composition (%volume)

Table 9. Volume of product gas (NL)

4.1.1. Liquid Product

Table 10. Operation condition of GC–FID Pyrolisis

Figure 14. Profile of chromatogram GC–FID feed and product RUN–01

Figure 18 shows the effect of reaction time for each time the RUN in the Autoclave 1L reactor to a uniform temperature rise, it means better performance and a control system stable.

Figure 15. Profile of chromatogram GC–FID feed and product RUN–05

Figure 18. The effect of reaction time against operation temperatur of autoclave 1L

Table 8 and Table 9 show that of the result 10 times RUN has done most of the gas producing hydrocarbons (HC) light C1 ~ C2 (CH4, C2H6) SNG equivalent except RUN-02. Product hydrocarbon gases (HC) light C1 ~ C3 (CH4, C2H6, C3H8) is produced by the RUN-01-05 RUN, RUN-07, RUN-

10 (where the RUN-03 is relatively small). While the Figure 16. Profile of chromatogram GC–FID feed RUN-05, RUN-07, RUN-10 are capable of producing and product RUN–07 hydrocarbon gases (HC) light C1 ~ C4 (CH4, C2H6, C3H8, n-C4H10 i-C4H10). The other 4 RUN (RUN- 04-06 RUN, RUN-08, RUN-09) less so produce the desired product.

Table 11 shows the material balance RUN-01, RUN- 05, RUN-07, RUN-10, where the RUN-05 is capable of producing the biggest hydrocarbon gases (HC) light C1 ~ C4 with N2 gas content is relatively small, while the product gas hydrocarbons (HC) light C1 ~ C4 generated by the RUN-01 RUN-07, RUN-10 is relatively small and this case less desirable in the Fischer-Tropsch Synthesis process because N2 gas content is still relatively high.

Figure 17. Profile of chromatogram GC–FID feed and product RUN–10

4.2. Discussion

4.2.1. Gas Product

Table 11 The material balance of Fischer–Tropsch Synthesis (Autoclave 1L)

Figure 19 and Figure 20 shows that although the Liquid Product RUN-01 only produces gas hydrocarbon (HC) light C1 ~ C3 is the smallest than RUN–05, RUN–07, During the study, only the slurry product is vacuum RUN–10, however, indicated to produce HC chain filtered and the liquid product was not carried further C> C5 ~ C12 (prediction of kerosene equivalent): distillation due to bumping. this means that the smaller product gas has a tendency to produce more oil. Figure 14, Figure 15, Figure 16 and Figure 17 shows the GC-FID chromatogram profile sample liquid product produced by the RUN–01, RUN–05, RUN– 07, RUN–10 have indicated a tendency HC products chain C> C5 ~ C12 (oil) which is relatively very small quantity and quality can not be known for sure (equivalent prediction kerosene), since the current vacuum distillation process (P = 10 mmHg using a solvent reagent C16H34) were bumping.

Products RUN–01 shows a comparison of the peak area on the residence time (retention time) was 31.804 (bait) and 31.789 (products) that decrease

product area. While the peak area products has Figure 19. Profile of chromatogram GC–FID oil increased in the residence time (retention time) 34 product RUN–01 699; 34 775; 35 182; it means components on the product a lot more than feed.

produce HC chain C > C5~C12 (oil): this means that the small gas produced products have a tendency to produce more oil. • Liquid products produced by RUN–01, RUN–05, RUN–07, RUN–10 have indicated tendency of products HC chain C > C5~C12 (oil) which is relatively very small quantity and quality can not be known for sure (equivalent prediction kerosene), since the current vacuum distillation process (P = 10 mmHg using a solvent reagent C16H34) were bumping.

References [1] Billings Gazette. (2005), "Schweitzer wants to convert Figure 20. Profile of chromatogram GC–FID oil Otter Creek coal into liquid fuel" August 2. product RUN– 01 [2]. Bruce C. Gates (2003), “Extending the Metal Cluster- Metal Surface Analogy” Angewandte Chemie International 5. CONCLUSIONS Edition in English, Volume 32, pp. 228–229. [3] Businessday.co.za. (2011), "PetroSA technology ready The results of the assessment on syngas utilization by for next stage | Archive | BDlive". Retrieved 2013-06-05. Fischer Tropsch Synthesis in the slurry–bed reactor [4] Clifford Krauss (2012) "South African Company to Build U.S. Plant to Convert Gas to Liquid Fuels".The New using Co/SiO2 catalyst as liquid synthetic fuel, it can York Times. Retrieved December 18, 2012. be concluded as follows: [5] Gerard P. Van Der Laan, A. A. C. M. Beenackers (1999): “Kinetics and Selectivity of the Fischer-Tropsch • During the research has been done 10 run– Synthesis”: A Literature Review. Catalysis Reviews: V 41, times uses 2 types of mixed-gas namely: (1) 60% H2, I 3&4, p.255. 30% CO, 10% N2 (H2/CO ratio = 2) for RUN–01, [6] http://www.choren.com. RUN–05, RUN–07, RUN–10 with Co/SiO2 Nacalai [7] http://www.fischer-tropsch.org / DOE / DOE _ reports catalysts, while (2) 54% H2, 30% CO, 10% CH4, 6% /510/510 – 34929/510 – 34929 N2 (H2/CO ratio = 1.8) for RUN–02, RUN–03, [8] http://www.rentechinc.com/ [9] Jamieson, Andrew.(2012), "Keeping the Options RUN–04, RUN–06, RUN–08, RUN–09 with Open". Petroleum Economist. Retrieved LNG. Co/SiO2 nature zeolith catalysts. [10] Kuipers E. W., Scheper C., Wilson J. H., Vinkenburg • According to the evaluation results by GC- I. H., Oosterbeek H.: (1996), “Non–ASF Product FID analysis from the 10 run–times conducted Distributions Due to Secondary Reactions during Fischer– showed that most of the gas producing hydrocarbons Tropsch Synthesis”. Journal of Catalysis: V 158, I 1, p.288. (HC) light C1~C2 (CH4, C2H6) SNG equivalent [11] Lane, Jim (Nov. 20, 2012)."Little Big Tech: Can except RUN–02. Product hydrocarbon gases (HC) Fischer-Tropsch technology work at smaller scale". light C1~C3 (CH4, C2H6, C3H8) is produced by the Biofuels Digest. Retrieved 26–04–2013 RUN–01, RUN–05, RUN–07, RUN–10 (RUN–03 is [12] Leckel, D. {2009}, "Diesel Production from Fischer– Tropsch: The Past, the Present, and New Concepts", relatively small). While the RUN–05, RUN–07, Energy Fuels, volume 23, 2342–2358. RUN–10 is capable of producing hydrocarbon gases [13] NewsRoom (2007), "UPM-Kymmene says to establish (HC) light C1~C4 (CH4, C2H6, C3H8, n-C4H10 i- beachhead in biodiesel market". Finland. C4H10) LPG equivalent. The other 4 run–times [14] Popular Mechanics (Feb 1952) "Construction of (RUN–04, RUN–06, RUN–08, RUN–09) less so World's First Synthesis Plant", p. 264. produce the desired product. [15] Smedley, Mark (2012), "Small GTL's Market Reach as • Product gas hydrocarbon (HC) light C1~C4 Great as Opec's, UK Firm Says". World Gas Intelligence. are the largest produced by the RUN–05 with N2 gas Retrieved 19th Dec 2012. content is relatively small, in contrast with the RUN– [16] Thomas G. Kreutz, Eric D. Larson, Guangjian Liu, 01, RUN–07, RUN–10 in the Fischer-Tropsch Robert H. Williams (2008), "Fischer–Tropsch Fuels from Coal and Biomass”, 25th Annual International Pittsburgh Synthesis process less desirable since the content of Coal Conference (29 Sept–2 Oct), Pittsburgh, N2 gas still relatively high. Pennsylvania, USA, p.6] • Product gas hydrocarbon (HC) light C1~C3 produced by the smallest compared to RUN–01, RUN–05, RUN–07, RUN–10, however indicated to