Fischer–Tropsch (FT) Synthesis to Biofuels (BtL Process)

Author(s):  
Cataldo De Blasio
Keyword(s):  
Author(s):  
Emanuele Martelli ◽  
Thomas G. Kreutz ◽  
Manuele Gatti ◽  
Paolo Chiesa ◽  
Stefano Consonni

In this work, the “HRSC Optimizer”, a recently developed optimization methodology for the design of Heat Recovery Steam Cycles (HRSCs), Steam Generators (HRSGs) and boilers, is applied to the design of steam cycles for three interesting coal fired, gasification based, plants with CO2 capture: a Fischer-Tropsch (FT) synthesis process with high recycle fraction of the unconverted FT gases (CTL-RC-CCS), a FT synthesis process with once-through reactor (CTL-OT-CCS), and an Integrated Gasification Combined Cycle (IGCC-CCS) based on the same technologies. The analysis reveals that designing efficient HRSCs for the IGCC and the once-through FT plant is relatively straightforward, while designing the HRSC for plant CTL-RC-CCS is very challenging because the recoverable thermal power is concentrated at low temperatures (i.e., below 260 °C) and only a small fraction can be used to superheat steam. As a consequence of the improved heat integration, the electric efficiency of the three plants is increased by about 2 percentage points with respect to the solutions previously published.


Author(s):  
Shahram Sharifnia ◽  
A. Khodadadi ◽  
Y. Mortazavi

The present study examines the effect of hydrogen distribution (HD) along a Co/SiO2 catalyst bed on Fischer-Tropsch (FT) synthesis. The synthesis is performed under two pressures of 1.0 and 9.0 atm and different H2/CO ratios. The results are compared to those of the usual co-feed, in which both CO and H2 are introduced to the bed inlet. By HD strategy, the methane selectivity is suppressed by as much as 25% and the C11+ selectivity is enhanced up to 26%. CO conversion and product selectivity exhibited a strong dependence on the operating pressure and H2/CO ratio, when hydrogen is distributed.


Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
Erling Rytter ◽  
Christian Aaserud ◽  
Anne-Mette Hilmen ◽  
Edvard Bergene ◽  
Anders Holmen

CO hydrogenation has been studied on cobalt foils as model catalysts for Fischer–Tropsch (FT) synthesis. The effect of pretreatment (number of calcinations and different reduction times) for cobalt foil catalysts at 220 °C, 1 bar, and H2/CO = 3 has been studied in a microreactor. The foils were examined by scanning electron microscopy (SEM). It was found that the catalytic activity of the cobalt foil increases with the number of pretreatments. The mechanism is likely an increase in the available cobalt surface area from progressively deeper oxidation of the foil, supported by surface roughness detected by SEM. The highest FT activity was obtained using a reduction time of only 5 min (compared to 1 and 30 min). Prolonged reduction caused the sintering of cobalt crystallites, while too short of a reduction time led to incomplete reduction and small crystallites susceptible to low turn-over frequency from structure sensitivity. Larger crystals from longer reduction times gave increased selectivity to heavier components. The paraffin/olefin ratio increased with the increasing number of pretreatments due to olefin hydrogenation favored by enhanced cobalt site density. From the results, it is suggested that olefin hydrogenation is not structure sensitive, and that mass transfer limitations may occur depending on the pretreatment procedure. Produced water did not influence the results for the low conversions experienced in the present study (<6%).


Author(s):  
Xun Wang ◽  
Yunhan Xiao

A co-production system based on FT synthesis reactor and gas turbine was simulated and analyzed. Syngas from entrained bed coal gasification was used as feedstock of low temperature slurry phase Fischer-Tropsch reactor. Raw synthetic liquid produced was fractioned and upgraded to diesel, gasoline and LPG. Tail gas composed of unconverted syngas and F-T light component was fed to gas turbine. Supplemental fuel (NG, or refinery mine gas) might be necessary, which was dependent on gas turbine capacity, expander through flow capacity, etc. FT yield information was important to the simulation of this co-production system. A correlation model based on Mobil’s two step pilot plant was applied. This model proposed triple chain-length-dependent chain growth factors and set up correlations among reaction temperature with wax yield, methane yield, and C2-C22 paraffin and olefin yields. Oxygenates in hydrocarbon phase, water phase and vapor phase were also correlated with methane yield. It was suitable for syngas, iron catalyst and slurry bed. It can show the effect of temperature on products’ selectivity and distribution. Deviations of C5+ components yields and distributions with reference data were less than 3%. To light gas components were less than 2%. User models available to predict product yields, distributions, cooperate with other units and do sensitive studies were embedded into Aspen plus simulation. Performance prediction of syngas fired gas turbine was the other key of this system. The increase in mass flow through the turbine affects the match between compressor and turbine operating conditions. The calculation was carried out by GS software developed by Politecnico Di Milano and Princeton University. The simulated performance assumed that the expander operates under choked conditions and turbine inlet temperature equals to NG fired gas turbine. A “F” technology gas turbine was selected to generate power. Various cases were investigated so as to match FT synthesis island, power island and gasification island in co-production systems. Effects of CO2 removal/LPG recovery, co-firing, CH4 content variation were studied. Simulation results indicated that more than 50% of input energy was converted to electricity and FT products. Total yield of gasoline, diesel and LPG was 136g-155g/NM3(CO+H2). At coal feed 21.9kg/s, net electricity exported to grid was higher than 100MW. Total production of diesel and gasoline (and LPG) was 118,000 tons(134,000tons)/Year. Under economic analysis conditions assumed in this paper, co-production system was economic feasible. The after tax profits can research 17 million EURO. Payback times were ranged from 6-7 years.


Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 872 ◽  
Author(s):  
Mohammad ◽  
Bepari ◽  
Aravamudhan ◽  
Kuila

Fischer–Tropsch (FT) synthesis was carried out in a 3D printed stainless steel (SS) microchannel microreactor using bimetallic Co-Ru catalysts on three different mesoporous silica supports. CoRu-MCM-41, CoRu-SBA-15, and CoRu-KIT-6 were synthesized using a one-pot hydrothermal method and characterized by Brunner–Emmett–Teller (BET), temperature programmed reduction (TPR), SEM-EDX, TEM, and X-ray photoelectron spectroscopy (XPS) techniques. The mesoporous catalysts show the long-range ordered structure as supported by BET and low-angle XRD studies. The TPR profiles of metal oxides with H2 varied significantly depending on the support. These catalysts were coated inside the microchannels using polyvinyl alcohol and kinetic performance was evaluated at three different temperatures, in the low-temperature FT regime (210–270 °C), at different Weight Hourly Space Velocity (WHSV) in the range of 3.15–25.2 kgcat.h/kmol using a syngas ratio of H2/CO = 2. The mesoporous supports have a significant effect on the FT kinetics and stability of the catalyst. The kinetic models (FT-3, FT-6), based on the Langmuir–Hinshelwood mechanism, were found to be statistically and physically relevant for FT synthesis using CoRu-MCM-41 and CoRu-KIT-6. The kinetic model equation (FT-2), derived using Eley–Rideal mechanism, is found to be relevant for CoRu-SBA-15 in the SS microchannel microreactor. CoRu-KIT-6 was found to be 2.5 times more active than Co-Ru-MCM-41 and slightly more active than CoRu-SBA-15, based on activation energy calculations. CoRu-KIT-6 was ~3 and ~1.5 times more stable than CoRu-SBA-15 and CoRu-MCM-41, respectively, based on CO conversion in the deactivation studies.


2011 ◽  
Vol 324 ◽  
pp. 197-200 ◽  
Author(s):  
Nadi Braidy ◽  
Carmen Andrei ◽  
Jasmin Blanchard ◽  
Nicolas Abatzoglou

χThe nanostructure of Fischer-Tropsch (FT) Fe carbides are investigated using aberration-corrected high-resolution transmission electron microscopy (TEM). The plasma-generated Fe carbides are analyzed just after synthesis, following reduction via a H2 treatment step and once used as FT catalyst and deactivated. The as-produced nanoparticles (NPs) are seen to be abundantly covered with graphitic and amorphous carbon. Using the extended information limit from the spherical aberration-corrected TEM, the NPs could be indexed as a mixture of NPs in the θ-Fe3C and χ–Fe5C2 phases. The reduction treatment exposed the NPs by removing most of the carbonaceous speSubscript textcies while retaining the χ–Fe5C2. Fe-carbides NPs submitted to conditions typical to FT synthesis develop a Fe3O4 shell which eventually consumes the NPs up to a point where 3-4 nm residual carbide is left at the center of the particle. Subscript textVarious mechanisms explaining the formation of such a microstructure are discussed.


2021 ◽  
Vol 8 ◽  
pp. 99-115
Author(s):  
Samuel Mubenesha ◽  
Chike George Okoye-Chine ◽  
Franscina Katuchero Ramutsindela ◽  
Joshua Gorimbo ◽  
Mahluli Moyo ◽  
...  

Fischer-Tropsch (FT) synthesis has been studied in the literature as a greener pathway to cleaner and sustainable hydrocarbons production. However, the cost to upscale laboratory FT formulations to pilot scale is significantly expensive. This work proposes a cheaper and scalable low-temperature FT modified iron ore catalyst that is mechanically suited for fixed bed reactors. The mechanical strength reported in this investigation was three times more than commercial alumina spherical pellets and, therefore, suitable for pilot scale scenarios. A manufacturing cost analysis of iron ore was estimated to be US$38.45/kg using the CatCost model, and the conventionally prepared iron catalyst was US$71.44/kg using the same model. The manufacturing cost estimations of modified iron ore were found to be 46% cheaper than a conventional commercial iron catalyst. The catalytic performance of the modified iron ore catalyst showed a CO conversion of 72.1% ±4.24, with WGS and C5+ selectivity 48.6% ±1.96 and 83.2% ± 5.24, respectively. These findings were comparable (both in CO conversion and product selectivity) to the ones reported by other researchers.


2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Teuku Mukhriza ◽  
Hartati Oktarina

Fischer-Tropsch (FT) Synthesis has been widely known for centuries as the process of converting syngas to liquid fuels. Several reactors including Slurry bubble column, fluidized-bed, and fixed bed reactors have been used for FTS on an industrial scale. Although science has seen remarkable development in technology for FT synthesis, the industry still faces challenges in optimizations of process parameters and achieved desired selectivity.  Extensive research has been continuously conducted to seek the best FT reactor offering heat uniformity and efficient heat transfer across the reactor to increase the catalytic activity and its lifetime. Dielectric Barrier Discharge (DBD) plasma has become one of the options to deal with these issues. This reactor work under low temperature delivers a synergistic effect between plasma and catalyst to break H2 and CO bond. DBD plasma is also suitable for feedstock with high H2/CO molar ratios. It is also found that FT catalyst such as cobalt catalyst used in DBD plasma was well dispersed on the support which in turn favour the selectivity toward liquid hydrocarbon.


Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 936 ◽  
Author(s):  
Irene Coronado ◽  
Aitor Arandia ◽  
Matti Reinikainen ◽  
Reetta Karinen ◽  
Riikka L. Puurunen ◽  
...  

In the Fischer–Tropsch (FT) synthesis, a mixture of CO and H2 is converted into hydrocarbons and water with diluted organics. This water fraction with oxygenated hydrocarbons can be processed through aqueous-phase reforming (APR) to produce H2. Therefore, the APR of FT water may decrease the environmental impact of organic waters and improve the efficiency of the FT process. This work aimed at developing a kinetic model for the APR of FT water. APR experiments were conducted with real FT water in a continuous packed-bed reactor at different operating conditions of temperature (210–240 °C), pressure (3.2–4.5 MPa) and weight hourly space velocity (WHSV) (40–200 h−1) over a nickel-copper catalyst supported on ceria-zirconia. The kinetic model considered C1-C4 alcohols as reactants, H2, CO, CO2 and CH4 as the gaseous products, and acetic acid as the only liquid product. The kinetic model included seven reactions, the reaction rates of which were expressed with power law equations. The kinetic parameters were estimated with variances and confidence intervals that explain the accuracy of the model to estimate the outlet liquid composition resulting from the APR of FT water. The kinetic model developed in this work may facilitate the development of APR to be integrated in a FT synthesis process.


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