Research on Simulation of Fischer-Tropsch Synthesis Based on Virtual Assembly

H-ZSM-5/cobalt/silica capsule catalysts with different crystallization time for direct synthesis of isoparaffins: simultaneous realization of space confinement effect and shape selectivity effect

Integrating high-temperature solid oxide electrolysis cells (SOECs) with exothermic Fischer-Tropsch (FT) synthesis can unlock significant synergies for enhancing process efficiency. In such a coupled system, syngas is generated via co-electrolysis, while the excess heat from the FT reactor is utilized to produce steam for the SOEC which can significantly improve energy utilization and system performance. In industrial FT reactors, single-pass syngas conversion typically ranges from 60–85% to avoid hot spot formation, necessitating recycling to boost conversion. This recycling leads to the accumulation of light hydrocarbons (C1–C6) in the gas phase, requiring a substantial purge stream that reduces product yield and overall carbon efficiency.To address these challenges, this work proposes a long-recycling approach, where FT tail gas is recycled into the SOEC, enabling hydrocarbon reforming directly within the system. This integration reduces the purge gas stream and introduces a cooling effect in the SOEC, facilitating higher current densities under isothermal operating conditions.A combined experimental and simulation study was conducted to explore the transient thermal effects of introducing FT tail gas into a 120 kW SOEC module, which consists of 24 stacks of electrolyte-supported cells (ESCs). Emulated FT tail gas compositions, representative of an industrial FT synthesis reactor, were introduced into the system. Transient simulations, performed using the validated TEMPEST reactor model, evaluated spatial and temporal temperature gradients within the SOEC, identifying operating regimes that could pose risks to system stability.From these analyses, optimized operating strategies were developed to minimize temperature gradients and enhance system reliability. Experimental validation demonstrated the efficacy of these strategies in maintaining stable and safe SOEC operation. This study highlights the potential of the proposed SOEC-FT integration to improve system performance, reduce carbon losses, and advance the development of sustainable, high-efficiency energy solutions.

Fischer-Tropsch Synthesis (FTS) on Fe-Cu-K/ZSM5 catalysts prepared by varying the amount of active components for a given amount of ZSM5 has been investigated to elucidate the effects of iron concentration. The catalysts were prepared by conventional wet impregnation method using ZSM5 and subsequently calcined at 500 °C for 5 h. The different catalytic performance is verified by the variation of microporosity such as surface area and pore size distribution of Fe-Cu-K/ZSM5, acidity, reducibility of active phases and the presence of various crystalline phases like α-Fe2O3, metallic iron and iron carbide. The characterization results are analyzed along with catalytic performance to arrive at optimum amount of active components and to obtain maximum selectivity of FTS products with high conversion of CO during FTS reaction. Fischer-Tropsch Synthesis (FTS) on Fe-Cu-K/ZSM5 catalysts prepared by varying the amount of active components for a given amount of ZSM5 has been investigated to elucidate the effects of iron concentration. The characterization results are analyzed along with catalytic performance to arrive at optimum amount of active components and to obtain maximum selectivity of FTS products with high conversion of CO during FTS reaction.

The Fischer–Tropsch synthesis (FTS) catalysts with high reduction levels were synthesized through an autocombustion method using citric acid (CA) as a reductant and nitrate ions (N) as oxidants. The as-synthesized catalysts were used directly in FTS reaction without further reduction. The effects of the promoter, reductant types and citric acid contents on the catalyst structures and FTS performance were systematically studied. Results indicated that the introduction of a small amount of promoter improved the catalyst reducibility during the autocombustion process, and significantly enhanced the FTS activity. The CO conversion of the catalyst increased rapidly from 0.8 to 41.4 % after Ru promotion for Co catalysts. The citric acid contents (molar ratio of citric acid to nitrates: CA/N) in the precursor also played an important role in controlling the structures and FTS performance of the catalysts. For the RuCo catalysts, when the CA/N molar ratio was increased, the metal reduction level increased and the Co crystalline size decreased but the activity of the catalyst first increased and then decreased while metal reduction level and the activity of the iron-based catalysts were decreased. An excessive amount of the reductant could result in more residual carbon species and decrease the activity of the catalyst. Compared with the iron-based catalyst prepared by the conventional co-precipitation method (CN), the CO conversion of the autocombustion catalyst with CA/N = 0.1 was higher than that of the catalyst CN. For different types of reductants (at the same molar ratio of reductants to nitrates = 0.3), the catalyst prepared by citric acid exhibited the highest activity whereas the catalyst synthesized by oxalic acid showed the lowest methane selectivity. The FTS catalysts prepared by the autocombustion method, which omits the complex and high-energy consumption reduction process, can be used directly for highly efficient FTS and thus will be more promising in the future.

The effect of syngas composition on the Fischer Tropsch synthesis over three-dimensionally ordered macro-porous iron based catalyst

The use of pulsing to limit the chain growth of the hydrocarbon products of the Fischer-Tropsch (FT) synthesis in order to maximize the yield of diesel-range (C{sub 10}-C{sub 20}) products was examined on three high-chain-growth-probability ({alpha} {ge} 0.9) FT catalysts. On a Co-ZrO{sub 2}/SiO{sub 2} FT synthesis catalyst the application of H{sub 2} pulsing causes significant increase in CO conversion, and only an instantaneous increase in undesirable selectivity to CH{sub 4}. Increasing the frequency of H{sub 2} pulsing enhances the selectivity to C{sub 10}-C{sub 20} compounds but the chain-growth probability {alpha} remains essentially unaffected. Increasing the duration of H{sub 2} pulsing results in enhancing the maximum obtained CO conversion and the instantaneous selectivity to CH{sub 4}. An optimum set of H{sub 2} pulse parameters (pulse frequency and duration) is required for maximizing the yield of desirable diesel-range C{sub 10}-C{sub 20} products. On a high-{alpha} Fe/K/Cu/SiO{sub 2} FT synthesis catalyst H{sub 2} pulsing enhances the yield of C{sub 10}-C{sub 20} but at the same time decreases the catalyst activity (CO conversion) and increases the selectivity to CH{sub 4}. On the other hand, pulsing with CO also increases the yield of C{sub 10}-C{sub 20} but has no impact on the selectivity to CH{sub 4} or CO{sub 2} and decreases catalytic activity only moderately. In contrast to these catalysts, H{sub 2} pulsing on a high-{alpha} Ru/alumina FT synthesis catalyst has only minimal effect on activity and product distribution, showing enhanced activity towards methanation and water-gas-shift at the expense of FT synthesis. However, these observations are based on experiments performed at a significantly lower reaction pressure (ca. 26 atm) and higher reaction temperature (210-250 C) than those commonly used for supported-Ru FT catalysts (typically 100-1000 atm, 160-170 C).

Ru promoted Co/SiO2 Fischer–Tropsch synthesis (FTS) catalysts with high reduction levels were synthesized through an autocombustion method using citric acid (CA) as a reductant and nitrate ions as oxidants. The as-synthesized catalysts were used directly in FTS reaction without further reduction. The effects of the ruthenium promoter, citric acid contents and reductant types on the catalyst structures and FTS performance were systematically studied. Results indicated that the introduction of a small amount of Ru (1 wt%) improved the reduction and dispersion of cobalt during the autocombustion process, and significantly enhanced the FTS activity. The CO conversion of the catalyst increased rapidly from 0.8 to 41.4% after Ru promotion. The citric acid contents (molar ratio of citric acid to nitrates: CA/N) in the precursor also played an important role in controlling the structures and FTS performance of the catalysts. With the increase of CA/N, the metal reduction level increased and the Co crystalline size decreased but the activity of the catalyst first increased and then decreased with gradually increasing CA/N. An excessive amount of the reductant could result in more residual carbon species and decrease the activity of the catalyst. For different types of reductants (at the same molar ratio of reductants to nitrates), the catalyst prepared by citric acid exhibited the highest activity whereas the catalyst synthesized by oxalic acid showed the lowest methane selectivity. The Ru promoted cobalt catalysts prepared by the autocombustion method, which omits the complex and high energy consumption reduction process, can be used directly for highly efficient FTS and thus will be more promising in the future.

Virtual assembly was introduced in the chemical process simulation, and the method of virtual assembly for common chemical process was studied. The process of biomass fuel ethanol was analyzed which is combined by the first-grade distillation system in industrial ethanol production and the salt-added extractive distillation system in fuel ethanol production, and the scene graph structure was established. According to the assembly characteristics of the chemical process, the assembly equipment model was designed and constructed. The assembly points were added, and the assembly, simulation and transitive properties of the assembly points were defined. The 1+1and 1+n universality assembly method was proposed. By choosing unit equipment freely to assembly, the complex distillation system was realized. Results have shown that the assembly effect was good and accuracy, the method was proved correct and feasible. It is of great significance in the visual design of chemical process, digital construction of chemical plant and development of three-dimensional (3D) chemical process simulation technology.

Process Simulation and Economic Analysis of Producing Liquid Transportation Fuels from Biomass

Fischer–Tropsch Synthesis over cobalt based catalyst supported on different mesoporous silica

Kinetics modelling of Fischer–Tropsch synthesis over an industrial Fe–Cu–K catalyst

Fischer–Tropsch synthesis: accounting for chain-length related phenomena

Impact of cobalt-based catalyst characteristics on the performance of conventional gas-phase and supercritical-phase Fischer–Tropsch synthesis

Object Hybrid Formalism for Modeling and Simulation of Chemical Processes

The new Ce‐promoted skeletal Fe catalysts with different Ce contents were prepared through alkali leaching of rapidly quenched ternary FeCeAl alloys and evaluated in the gas‐phase Fischer–Tropsch synthesis reaction. N2 physisorption and XRD analysis confirmed the function of Ce as a structural promoter. In the Fischer–Tropsch synthesis reaction, the incorporation of Ce markedly improved the activity and selectivity to C5+ hydrocarbons. Characterizations of the catalysts after Fischer–Tropsch synthesis confirmed the function of Ce as a chemical promoter. We also confirmed that the catalytic activity is associated with the concentrations of the surface polymeric and, to a lesser extent, atomic carbonaceous species and the C5+ selectivity correlated well with the surface concentration of Hägg carbide. We identified a linear relationship between the concentrations of the CeIII cations and Hägg carbide, which clearly substantiated the hypothesis that the chemical effect of Ce is mediated by the Fe0CeIII ensembles facilitating the formation of Hägg carbide.