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In the present work, the Fischer–Tropsch synthesis (FTS) is carried out through simulation. This reaction uses a gas mixture, called synthesis gas, composed of carbon monoxide rich in hydrogen (H2/CO > 2.5), to form medium and long chain hydrocarbons (C5+). For the modeling of this system, a packed bed reactor with a cobalt-based catalyst has been considered, which promotes the polymerization of methylene species, selective to linear paraffins and 1-olefins. The objective of this work is evaluating the impact of operation variables, such as feed flows and temperature, coolant flow, system pressure, on the chain length distribution of the products. Current operating policies does not promote selectivity to the production of synthetic gasolines (C5–C12), because of the drastic increase in the temperature inside the reactor as consequence of the high exothermicity of the reactions (ΔH = −170 kJ mol−1). It has been impossible to maintain these reactions within the appropriate temperature range (475–520 K) without the presence of an external agent that manages the available heat, for this project molten sales have been proposed as a cooling medium (KNO3–NaNO3), based on its favorable heat transfer characteristics. By analyzing the system responses, the open loop model has allowed us to explore multiple hydrocarbon production scenarios, specifically highlighting the increasing of the yield of synthetic gasoline (48 wt%) in the products, from a defined molten salts (coolant) countercurrent flow range (7.05E-2 at 2.50E-1 m/h). It was noticed that this heat management allowed us to obtain a specific range of hydrocarbons, representing the opportunity to control the growth of the chain length. In conclusion, this analysis will lay the foundations for the design control policies, which help to increase current yields of synthetic gasoline, making it possible to achieve the desired quality for the immediate future. [ABSTRACT FROM AUTHOR]

Solar thermochemical redox cycles followed by a synthesis process are a potentially carbon-neutral way to produce versatile carbonaceous products. The required high temperature of the redox cycle, however is correlated to high heat losses and limits the process efficiency. Use of natural gas as a reductant can lower the temperature, but this approach depends on a fossil carbon source and is not carbon neutral. We propose a novel concept in which short chained hydrocarbons, which are a by-product of the synthesis process are recycled and used as a reductant in the solar redox cycle. In the present study we investigate the use of C 1 –C 4 alkanes, which are by-products of high or low temperature Fischer-Tropsch synthesis as reductants in a ceria-based redox cycle. Thermodynamic simulation results imply that both higher degrees of reduction and lower reduction temperatures are feasible and that the energy demand for the reduction step can be decreased by 61% or 24% for high or low temperature Fischer-Tropsch synthesis, respectively. • A two-step solar ceria redox cycle coupled to Fischer-Tropsch synthesis is investigated. • Gaseous by-products from Fischer-Tropsch synthesis are recycled and used as reductant in the redox cycle. • Using the reductant, part of the ceria can be reduced at energetically beneficial conditions. • Recycling allows downscaling of the redox cycle. • Energy savings in the reduction and product quality are evaluated. [ABSTRACT FROM AUTHOR]

The shape‐defined ZnFe2O4 spinel with cubic and octahedral morphology was hydrothermally synthesized, respectively, and used as catalyst precursor for Fischer–Tropsch synthesis (FTS). The structure of ZnFe2O4 spinel was changed to ZnO and Fe5C2 (Fe5C2/ZnO) after reduction and carbonization. Interestingly, ZnFe2O4 with cubic morphology exhibited much higher catalytic activity and selectivity toward low‐carbon olefins (C2–C4) than the octahedral one under identical conditions, and the latter tended to produce the saturated alkanes. The primary properties of ZnFe2O4 materials before and after reduction were systematically studied through a series of characteristic technologies to reveal the difference in catalytic performance between the two ZnFe2O4 spinels with different morphologies. [ABSTRACT FROM AUTHOR]

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ABSTRACT As the world shifts towards renewable and sustainable energy sources, converting syngas into hydrocarbons using Fischer–Tropsch synthesis (FTS) catalysts is crucial. In this work, a series of copper‐modified iron‐based catalysts with cerium and strontium promoters supported on γ‐Alumina as follows were prepared using a wet‐impregnation method: FCA (18Fe/4Cu/γ‐Al2O3), FCCA (18Fe/4Cu/2Ce/γ‐Al2O3), FCSA (18Fe/4Cu/2Sr/γ‐Al2O3), and FCCSA (18Fe/4Cu/1Ce/1Sr/γ‐Al2O3). The phase, structure, and morphology of the catalysts were characterized using X‐ray diffraction (XRD), Brunauer–Emmett–Teller (BET) specific surface area analysis, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), inductively coupled plasma–atomic emission spectrometry (ICP‐AES), hydrogen temperature‐programmed reduction (H2‐TPR), and hydrogen temperature‐programmed desorption (H2‐TPD). The impacts of Ce and Sr, individually and in combination, on the structure, adsorption, reduction, and catalytic performance of the catalysts were evaluated in a fixed bed reactor at 300°C, 2.0‐MPa pressure, a time of stream of 168 h, and an H2/CO ratio of 1. The CO conversion and product selectivity were calculated using gas chromatography results, highlighting the synergistic effect of Ce and Sr promoters on hydrocarbon product distribution. The doubly promoted FCCSA catalyst exhibited a high CO conversion rate of 77.65%, CO2 selectivity of 43.5%, C2‐C4 selectivity of 55.89%, C5+ selectivity of 85.62.0%, and a yield of 43.19%, surpassing FCA, FCCA, and FCSA catalysts. Similar characteristics, CO conversion, and product selectivity were achieved for FCCSA during long‐term 336‐h FTS runs, indicating stability. [ABSTRACT FROM AUTHOR]

Cobalt (Co) is widely used in Fischer–Tropsch synthesis (FTS), converting synthesis gas, carbon monoxide + hydrogen (CO + H2), to long-chain hydrocarbons. The adsorption of CO on the Co surface is the key step in FTS. In this work, the effect of CO adsorption sites on the reactions between CO and H2 was investigated by using density functional theory (DFT). The energetics and structures of the reactions between the adsorbed CO (CO*) and H2/adsorbed H2 (H2*)/adsorbed H atom (H*) were calculated. The results show that the reaction between CO* and H2 is initiated by the molecular adsorption of H2 on the Co surface. The reactions between CO* and H2*/H* are influenced by CO adsorption sites. For the reaction system of CO* + H2*, it has the lowest reaction barrier when CO is adsorbed at the hcp site, while for CO* + H*, it has the lowest reaction barrier when CO is adsorbed on the top site. Kinetic analysis indicates that to improve the reactivity of CO + H2 in FTS, the adsorption of CO should be controlled to favour the top and bridge sites. This article is part of the theme issue 'Celebrating the 15th anniversary of the Royal Society Newton International Fellowship'. [ABSTRACT FROM AUTHOR]

The surface iron of iron carbide has been identified as active in Fischer-Tropsch synthesis (FTS), but the effect of surface carbon remains a topic of debate. Herein, to clarify the effect of surface carbon of iron carbide on FTS, we conducted a density functional theory (DFT) study on CO adsorption, H 2 activation and CO hydrogenation over ε -Fe 2 C and θ -Fe 3 C. Compared to Fe 3 C(111), the Fe 2 C(111) facet exhibits more low-coordinated carbon, benefiting for CO adsorption and H 2 activation. Because of the low-coordinated carbon, the Fe 2 C(111) is more active for FTS than Fe 3 C(111), not only through the formation of CH 2 species with H atoms, but also through the direct C–C coupling for the carbon chain growth. The consumed carbon on Fe 2 C(111) can be recovered timely by absorption and direct dissociation of CO, ensuring the sustainability of the carbon chain growth. This work contributes to a comprehensive understanding of the FTS mechanism over iron carbide surface. [Display omitted] • Effect of surface carbon of iron carbide on FTS was studied by DFT calculations. • Fe 2 C(111) has more low-coordinated carbon comparing with Fe 3 C(111). • Low-coordinated carbon promotes H 2 activation, CO adsorption and hydrogenation. • Surface carbon on Fe 2 C(111) can be consumed by C–C coupling during FTS. • This work contributes to a comprehensive understanding of FTS over iron carbide. [ABSTRACT FROM AUTHOR]

This paper presents a bibliometric review on biogas reforming for the production of sustainable aviation fuel. The central themes are catalyst stability and syngas H 2 /CO ratio. It begins with a summary of bibliometric data, literature trends, and most productive agents. Followed by citation analysis on dry reforming (DR) and steam reforming (SR), including internal reforming in fuel cells. Then, a statistical exploration of literature data on reforming in nickel catalysts, followed by the thermodynamic effects of temperature, pressure, and H 2 O/CH 4 ratio. For Sustainable Aviation Fuel (SAF) production, steam reforming appears as the best option. The biggest gaps in the biogas reforming literature are kinetic studies and pressure effect assessments, for scale-up. [Display omitted] • Steam reforming syngas is most appropriate for Sustainable Aviation Fuel production. • Dry reforming values CO 2 but still presents major challenges to industrial implementation. • Biogas reforming literature is poor in studies of the effect of pressure, and reaction kinetics. • Nickel loads have negative correlation with catalyst activity. The H 2 O concentration, with the conversion and H 2 /CO ratio. [ABSTRACT FROM AUTHOR]

The impact of radial dispersion of both heat and mass on the behavior of cooled fixed‐bed reactors was explored using a two‐dimensional reactor model. This study accounted for dispersion through an effective radial thermal conductivity (λrad) and a radial dispersion coefficient of mass (Drad), with Fischer–Tropsch synthesis serving as an illustrative process example. Under moderate reaction conditions and hence still rather gentle radial temperature profiles, the effect of mass dispersion on reactor performance was found to be minimal, even if disregarded (Drad = 0), whereas dispersion of heat (λrad) always significantly impacts reactor behavior. Nevertheless, for precise thermal runaway predictions by a reactor model, incorporating mass dispersion by a realistic Drad value is essential. [ABSTRACT FROM AUTHOR]

Among the alkali metals, potassium is known to significantly shift selectivity toward value-added, heavier alkanes and olefins in iron-based Fischer–Tropsch synthesis catalysts. The aim of the present contribution is to shed light on the mechanism of action of alkaline promoters through a systematic study of the structure–reactivity relationships of a series of Fe oxide FTS catalysts promoted with Group I (Li, Na, K, Cs) alkali elements. Reactivity data are compared to structural data based on in situ, synchrotron-based XRD and XPS, as well as temperature-programmed studies (TPR-H2, TPC-CO, TPD-CO2, and TPD-H). It has been observed that the alkali elements induced higher carburization rates, higher basicities, and lower adsorbed hydrogen coverages. Catalyst stability followed the trend Na-Fe > unpromoted > Li-Fe > K-Fe > Cs-Fe, being consistent with the ability of the alkali (Na) to prevent active site loss by catalyst reoxidation. Potassium was the most active in promoting high α hydrocarbon formation. It is active enough to promote CO dissociative adsorption (and the formation of FeCx active phases) and decrease the surface coverage of H-adsorbed species, but it is not so active as to cause premature catalyst deactivation by the formation of a carbon layer resulting in the blocking active sites. [ABSTRACT FROM AUTHOR]

In the present work we have investigated the oligomerization process of Fischer-Tropsch synthesis products - gasoline (C5-C10) and diesel (C11-C18) hydrocarbon fractions with a total olefin content (consisting mainly olefins with a branched isomeric chain) of 79.3 and 31.8 wt.%, respectively. Oligomerization was carried out by radical initiation method using azobisisobutyronitrile, benzoyl peroxide, dicumyl peroxide and methyl ethyl ketone peroxide (Butanox M-50) as initiators. It was established that the yield of the oligomerization process depending on the initiator used decreases in the following order: azobisisobutyronitrile > benzoyl peroxide > dicumyl peroxide > Butanox M-50. It was determined that when the oligomerization is carried out in polar solvents such as acetone and dichloromethane the yield of product increases by ~2.1 and ~1.7 times, respectively, while at the same time adding a non-polar solvent such as tetrachloromethane to the reaction mixture decreases the product yield by ~2.0 times. The optimal technological parameters for carrying out oligomerization process of synthetic gasoline and diesel fractions were determined: where azobisisobutyronitrile, content 0.5 wt.%., is used as an initiator, acetone as solvent, with reaction temperature of 200 °C, and duration of 12 hrs. under inert atmosphere. The product yield from the diesel fraction is 39.5 %, and from the synthetic gasoline fraction - 36.0 %. At the same time, in terms of characteristics, the oligomerization product of the diesel fraction showed properties similar to commercially available Base oil 3cSt (Group III), and the gasoline fraction showed properties on par with the commercially produced PAO-2 (Group IV). [ABSTRACT FROM AUTHOR]

The high selectivity of C─C coupling reactions in Fischer–Tropsch synthesis (FTS) is often limited due to the difficulty in the regulation of transition metals acting as active sites to balance between C─C chain propagation and over hydrogenation. Herein, BCN‐supported CoFe alloy catalyst has been successfully constructed for promoting C─C chain propagation. When exposed to light irradiation, the CoFe‐BCN catalyst exhibits a higher CO conversion of 18.4% with the enhanced selectivity toward multi‐carbon (C2+) hydrocarbons that increases from 22.4% to 64.1%, and the reduced over hydrogenation to CH4 that decreases from 74.8% to 25.4% in contrast to Co‐BCN catalyst. Structural characterizations indicate that introducing Fe to create CoFe alloy can decrease the d‐band center of Co, which significantly promotes C─C coupling reactions but weakens hydrogenation in FTS process. The findings underscore the potential of modifying catalysts with metal atoms to optimize their electronic structure to regulate reaction pathways in CO hydrogenation for high‐value products formation. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis (FTS) converts syngas into multi-carbon products, whose distribution is highly dependent on the catalyst structure. Here, nano-iron catalysts with different silica supports were prepared, and their activities and durability for Fischer-Tropsch to olefins (FTO) process were investigated. Fe/KCC-1 demonstrated the best FTO catalytic selectivity of 25.0% for C2–4= and an olefin-to-paraffin ratio of 1.68. Its open pore structure allowed primary olefins to escape quickly from the catalyst surface, lowering the probability for secondary reactions. However, its durability was lower than Fe/SBA-15 due to coke formation, pore structure collapse and Fe particle agglomeration. The thermal stability of SBA-15 resulted in its better durability, and the encapsulated Fe particles inside the cylindrical mesopores also allowed better resistance to sintering. However, the less open structure of Fe/SBA-15 led to longer residence time for the primary olefins and increased possibility for secondary reactions, causing undesired chain growth. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis (FTS) is viewed as an effective method for producing clean fuels. Catalysts with high activity and selectivity, especially the latter, are the key to improving the catalytic performance. Herein, we report the preparation of an excellent bifunctional Fe + ZSM5 catalyst by employing novel hierarchical porous Fe2O3 cage particles as FTS sites and porous ZSM5 as catalytic cracking sites. The selectivity for gasoline fuels (C5-C11) selectivity over the Fe + ZSM5(33) catalyst is as high as 65.1 wt%, which is greater than that of traditional outstanding than the traditionally zeolite-supported and physically mixed bifunctional catalysts. The enhanced catalytic performance can be attributed to the weak acid content governing the catalytic cracking. ZSM5 zeolite with a suitable weak acid content and desorption temperature can facilitate the cracking of C12+ hydrocarbons, thereby facilitating the C5-C11 selectivity and inhibiting the deactivation of active sites resulting from the aggregation of C12+ hydrocarbons. Fe + ZSM5(27) with an suitable weak acid content provides a higher CO conversion of 93.6% combined with an excellent C5-C11 selectivity of 62.7 wt%. This finding provides a promising strategy for designing bifunctional catalysts with controllable product distribution. [ABSTRACT FROM AUTHOR]

Extractive distillation is used for separating oxygenates from other components in the C6 cut oil from Fischer‐Tropsch Synthesis followed by separating 1‐hexene from N‐hexane using the same solvent as the extractant. Furfural (FUR) is identified as an excellent solvent for extractive distillation of the C6 cut from FTS oil for separating oxygenates from other components as well as for separating 1‐hexene from N‐hexane via searching from more than 100 solvents by simulation using Aspen Plus. The behavior of the newly found solvent FUR is compared with that of the reported best solvent N‐methyl‐2‐pyrrolidone (NMP) and the results show that FUR scheme has the advantages of lower market price, lower dosage needed, less reboiler duty required and higher overall tray efficiency for fulfilling the same separation task. [ABSTRACT FROM AUTHOR]

Lower olefins, produced from syngas through Fischer-Tropsch synthesis, has been gaining worldwide attention as a non-petroleum route. However, the process demonstrates limited selectivity for target products. Herein, a hybrid catalyst system utilizing Fe-based catalyst and SAPO-34 was shown to enhance the selectivity toward lower olefins. A comprehensive study was conducted to examine the impact of various operating conditions on catalytic performance, such as space velocity, pressure, and temperature, as well as catalyst combinations, including loading pattern, and mass ratio of metal and zeolite. The findings indicated that the addition of SAPO-34 was beneficial for enhancing catalytic activity. Furthermore, compared with AlPO-34 zeolite, the strong-acid site on SAPO-34 was identified to crack the long-chain hydrocarbons, thus contributing to the lower olefin formation. Nevertheless, an excess of strong-acid sites was found to detrimentally impact the selectivity of lower olefins, attributed to the increased aromatization and polymerization of lower olefins. The detailed analysis of a hybrid catalyst in Fischer-Tropsch synthesis provides a practical strategy for improving lower olefins selectivity, and has broader implications for the application of hybrid catalyst in diverse catalytic systems. [ABSTRACT FROM AUTHOR]

Abstract In this study, the improvement of heat transfer was applied to eliminate hotspots of a highly exothermic reaction, Fischer–Tropsch synthesis (FTS), by means of two facile methods: (I) adding high thermal conductive materials media diluted in catalysts (SiC and Al chips), and (II) using structured reactors equipped with well-designed structured catalysts with advantages of heat dissipation/removal. The 20%Co/SiO2 catalyst powder prepared by simple impregnation was employed for constructing structured catalysts and granular packed bed catalysts. The structured catalyst was prepared by coating method of Co/SiO2 slurry on an aluminum spiral and plate substrate. The catalytic performance of as-prepared catalysts was then tested for FTS in a fixed-bed reactor at 210–230 °C, 20 bar. Both gaseous and liquid products were collected and analyzed. The heat transfer improvement of packed bed catalytic system and structured catalytic system were compared and discussed. As a result, the structured catalytic system with spiral structured catalyst can provide the best improvement of heat/mass transfer, resulting in enhanced diesel selectivity, though the oil production rate was unsatisfactory. Meanwhile, among the packed bed catalytic systems, SiC media possessed the best heat removal material, producing the highest oil yield. In addition, the fresh and spent catalysts were analyzed by several techniques including TEM, SEM, XRD, BET, ICP-OES, H2–TPR, and TGA to relate the physicochemical properties of the prepared catalysts and its FTS performance.

Traditionally, Fischer–Tropsch (FT) synthesis is performed using thermal catalysts and syngas (CO and H2) under high‐pressure and high‐temperature conditions. However, this study introduces an approach that relies on FT chemistry assisted by electrochemistry, referred to here as direct electrochemical (EC) FT chemistry, under ambient conditions. A series of CH4, CnH2n, and CnH2n+2 hydrocarbons (n = 1–7) is successfully produced over gold (Au) nanoparticle‐loaded perovskite strontium titanate (SrTiO3) nanostructures grown on rutile TiO2 supported on Ti. Au (1.0 nm)–SrTiO3 shows the best interface formation, with the highest Faradaic efficiency for C2+ hydrocarbons. This direct EC‐FT process proceeds via a C─C coupling chain growth reaction at the Au‐SrTiO3 interface as evidenced by the hydrocarbon weight distribution analysis and density functional theory calculations. The robust combination of experimental and computational findings reveals that optimum conditions for producing surface hydrogenation and C─C coupling polymerization, initiated by surface *CO and *H are achieved by controlling the undercoordinated Au at the perimeter sites of supported Au nanoparticles and by ensuring a harmonized density of states between Au and SrTiO3. This EC‐FT process opens a promising avenue for the direct conversion of CO2 and H2O into value‐added long‐chain hydrocarbons. [ABSTRACT FROM AUTHOR]

Depletion of oil and gas resources is a major concern for researchers and the global community. Researchers are trying to develop a way to overcome these issues using the Fischer-Tropsch synthesis (FTS) process. The FTS reaction converts a mixture of hydrogen and carbon monoxide gases into a liquid fuel. The reactions are performed in the reactor and in the presence of a catalyst. A series of catalysts, such as iron, cobalt, nickel, and ruthenium, have been used for the FTS process. In iron-based catalysts, the Fe5C phase is the active phase that produces C5+ hydrocarbons. At higher conversion rates, the presence of water in the products is a problem for cobalt catalysts because it can trigger catalyst deactivation mechanisms. Ni-based catalysts play key roles as base catalysts, promoters, and photothermal catalysts in FTS reactions to produce different useful hydrocarbons. Ruthenium catalysts offer not only high activity but also selectivity toward long-chain hydrocarbons. Moreover, depending on the Ru particle size and interaction with the oxide support, the catalyst properties can be tuned to enhance the catalytic activity during FTS. The detailed reaction pathways based on catalyst properties are explained in this article. This review article describes the issues and challenges associated with catalysts used for the FTS process. [ABSTRACT FROM AUTHOR]

New bifunctional composite catalysts for the Fischer—Tropsch synthesis were developed on the basis of a mixture of the Co—Al2O3/SiO2 catalyst, meso-HZSM-5 hierarchical mesoporous zeolite, and boehmite binder. The mesoporous zeolite was obtained by alkaline treatment of the industrial HZSM-5 zeolite. The developed catalysts are suitable for one-pot conversion of syngas into linear C5+ hydrocarbons, which then undergo cracking and isomerization reactions. The effect of the concentration of NaOH solution on the porosity and catalytic efficiency of the obtained meso-HZSM-5 zeolite was studied. The performances of the bifunctional catalysts obtained from alkali-treated and pristine HZSM-5 in the conversion of syngas were compared. In the presence of the catalyst based on the alkali-treated zeolite, the total productivity to C5+ hydrocarbons somewhat decreases. However, the increase in the total yield of branched and unsaturated hydrocarbons provides the formation of motor fuels with high anti-knock properties. [ABSTRACT FROM AUTHOR]

Structured Fischer–Tropsch synthesis catalysts were tested in tubular reactors of industry-standard diameters of 0.5 or 0.75 inches. The structured catalyst bed was manufactured by the obturation of a straight bunch of graphite-based extrudates (D = 1.5 mm, L = 30 mm). A conventional loose bed of granulated catalyst (D = 1.5 mm, L = 3 mm) was tested as a reference. In a 1000–3000 h−1 syngas space velocity range, structured and loose catalyst bed testing showed no significant differences in their main catalytic parameters. Nevertheless, their C5+ hydrocarbon group composition was quite different, i.e., the alkene fraction rose from 9 to 23%, while n-alkanes dropped from 81 to 64%. This could be a result of secondary reaction intensification in the conventional loose bed due to its zeolite acid site's higher availability. Further FTS testing of the structured catalysts in 4000–6000 h−1 manifested distinctive limits in C5+ productivity for 0.5 and 0.75 inches of 512 kg C5+/(m3 reactor·h) and 362 kg C5+/(m3 reactor·h), respectively. This may be explained by limitations in structured bed thermal conductivity. It suggests that the arrangement of extrudates in the structured catalyst can significantly affect the reaction heat and mass transfer conditions and affords new opportunities for group composition control by means of catalyst bed organization. [ABSTRACT FROM AUTHOR]

Branched-chain surfactants have lower equilibrium surface tension, superior wettability and emulsifying performance, making them suitable for exclusive applications. Linear α-olefins are rich in coal-based Fischer–Tropsch synthesized liquid products and are promising building blocks for the synthesis of branched-chain surfactants via dimerization and subsequent C=C bond functionalization. Herein, a new series of branched ethoxylate non-ionic surfactants (MDC6En) were prepared using 2-butyl-1-octene (1-hexene dimer, DC6), obtained by the dimerization of coal-based Fischer-Tropsch synthesized 1-hexene, as the hydrophobe via hydroxylation and ethoxylation. In particular, the hydroxylation of DC6 was carried out in a one-pot tandem hydroformylation and hydrogenation over unmodified Co2(CO)8 under mild conditions (140 °C and 4–8 MPa, CO:H2 = 1:1). A thorough investigation of their surfactant properties was carried out, including equilibrium surface tension, dynamic surface tension, foaming properties, wetting power, and emulsifying power. The results indicate that MDC6E9 performs comparably to a commercially available branched-chain surfactants, the iso-tridecyl alcohol ethoxylates (MULTISO 1390). This research provides a new direction for the synthesis of branched nonionic surfactants using Fischer–Tropsch synthesized products, further promoting the development of coal-based fine chemicals. [ABSTRACT FROM AUTHOR]

The results of testing the technology of preparing a bifunctional cobalt catalyst used to synthesize hydrocarbons from CO and H2, obtained by extruding a mixture of Co-Al2O3/SiO2 catalyst and HZSM-5 zeolite powders with a binder (boehmite) under industrial conditions (two batches of 50 kg each) are presented. The catalyst technology is tested on equipment at the Ishimbay Specialized Chemical Catalyst Plant (Russia). The resulting samples of industrial catalyst are studied via XRF, H2-TPR, and DTG, and tested in the synthesis of hydrocarbons from CO and H2 at 250°C, a pressure of 2.0 MPa, and a gas hourly space velocity of 1000 h−1. It is shown that the bifunctional cobalt catalyst for producing low pour-point diesel fuel under industrial conditions allows properties of the catalyst obtained under laboratory conditions to be reproduced. The technology for obtaining the catalyst can be recommended for the production of industrial batches. It is found that changing the conditions of the catalyst's heat treatment and the presence/absence of a peptizer and pore former do not appreciably reduce the productivity of C5+ hydrocarbons. The amount of the diesel fraction in C5+ products obtained on industrial catalyst samples remains at the same level as on the laboratory catalyst sample. At the same time, the low-temperature properties of diesel fuel obtained on all catalyst samples have similar values. The best low-temperature properties of diesel fuel are obtained on an industrial sample synthesized without a peptizer and a pore-forming component. The cloud point and the point of liquid loss are −16 and −24, respectively. [ABSTRACT FROM AUTHOR]

The Au/TiO 2 model catalyst has been extensively studied across various applications, yet its utilization in electrochemical CO 2 and CO reduction (EC CO 2 R and COR) remains underexplored. In this study, we employed the Au/TiO 2 /Ti system, prepared via a two-step process: initially forming rutile TiO 2 on metallic Ti through laser-assisted methods, followed by sputtering Au onto the surface. The experimental conditions included varying concentrations of KHCO 3 and phosphate, applied potentials, Au overlayer thickness, and laser treatment parameters for the Ti-based catalysts. The major products detected were syngas (CO and H 2), which varied with experimental settings, along with liquid formate and other hydrocarbons. The study also examined the role of surface species like *CO and H* in facilitating C–C coupling, drawing parallels to traditional Fischer-Tropsch (F-T) synthesis. Spectroscopic analyses, including XPS and UPS, were utilized to investigate interfacial electronic structures, oxidation states, and overlayer stability post-electrochemical processing. This research contributes to a deeper understanding of EC CO 2 R and COR mechanisms on Au/Ti electrodes, providing valuable insights into optimizing electrode design and operational conditions for enhanced catalytic efficiency in syngas production and direct F-T chemistry. [Display omitted] • Au/TiO 2 /Ti system was prepared by laser-assisting TiO 2 formation on Ti, followed by sputtering Au. • A tunable H 2 /CO ratio was by varying electrolyte concentrations and applied potentials in electrochemical CO 2 reduction. • Fischer-Tropsch synthesis pathway was understood through the role of *CO and H* in facilitating C–C coupling. • XPS and UPS revealed the oxidation states, interfacial electronic structures, and stability of Au overlayer. [ABSTRACT FROM AUTHOR]

In this study, the improvement of heat transfer was applied to eliminate hotspots of a highly exothermic reaction, Fischer–Tropsch synthesis (FTS), by means of two facile methods: (I) adding high thermal conductive materials media diluted in catalysts (SiC and Al chips), and (II) using structured reactors equipped with well-designed structured catalysts with advantages of heat dissipation/removal. The 20%Co/SiO2 catalyst powder prepared by simple impregnation was employed for constructing structured catalysts and granular packed bed catalysts. The structured catalyst was prepared by coating method of Co/SiO2 slurry on an aluminum spiral and plate substrate. The catalytic performance of as-prepared catalysts was then tested for FTS in a fixed-bed reactor at 210–230 °C, 20 bar. Both gaseous and liquid products were collected and analyzed. The heat transfer improvement of packed bed catalytic system and structured catalytic system were compared and discussed. As a result, the structured catalytic system with spiral structured catalyst can provide the best improvement of heat/mass transfer, resulting in enhanced diesel selectivity, though the oil production rate was unsatisfactory. Meanwhile, among the packed bed catalytic systems, SiC media possessed the best heat removal material, producing the highest oil yield. In addition, the fresh and spent catalysts were analyzed by several techniques including TEM, SEM, XRD, BET, ICP-OES, H2–TPR, and TGA to relate the physicochemical properties of the prepared catalysts and its FTS performance. [ABSTRACT FROM AUTHOR]

Cobalt carbides have been recognized as an active phase for the production of light olefins and alcohols in Fischer–Tropsch synthesis. In this study, in situ X-ray diffraction experiments were performed to investigate the stability and catalytic performance over a single-phase Co3C catalyst under reaction conditions. The in situ X-ray diffraction results indicated that the Co3C phase remained stable with no significant changes until the temperature reached 300 °C. The high stability can be attributed to the twinning structure of the single-phase Co3C catalyst. The catalytic evaluation results showed that the single-phase Co3C catalyst had higher activity with high selectivity to long-chain products due to the unique surface structure of Co3C. This work provides guidance for the rational design of efficient cobalt carbide catalysts for Fischer–Tropsch synthesis reactions. [ABSTRACT FROM AUTHOR]

Cobalt-based catalysts exhibit excellent reactivity and carbon chain growth capability in the Fischer-Tropsch synthesis reaction, and their catalytic performance is closely related to the reduction degree and size of metal Co particles. Regulating the reduction degree and dispersion degree of metal Co by adding promoters is an important way to enhance their catalytic performance in Fischer-Tropsch synthesis reaction. By using SiC as a support with chemical inertness and good thermal conductivity, and adding a small amount of nanodiamonds (NDs) with rich surface functional groups as structural regulators, the dispersion degree and reduction degree of Co species in the catalyst were effectively improved, and its catalytic performance in Fischer-Tropsch synthesis reaction was enhanced. The results of N2 physical adsorption/desorption show that the addition of NDs has little effect on the parameters such as specific surface areas and pore sizes of the catalysts. The results of CO chemisorption show that the addition of an appropriate amount of NDs promotes the dispersion of active metal Co in the catalysts, increases the surface area of metal Co and provides more active sites for the Fischer-Tropsch synthesis reaction. The results of transmission electron microscopy (TEM) show that after the addition of NDs to Co/SiC (m(NDs):m(SiC) = 1.0%), the particle sizes of metal Co in the catalysts are reduced, and NDs are uniformly dispersed on the catalyst surface. The results of H2-temperature programmed reduction (H2-TPR) and CO-H2-temperature programmed surface reaction (CO-H2-TPSR) show that the addition of NDs reduces the reduction temperature of Co3O4 to metal Co and promotes the reduction of Co3O4 and the activation of CO. Compared with the Co/SiC catalyst, the NDs-modified Co/1.0NDs-SiC (W(Co) = 10%, OT(NDS):M(SiC) = 1.0%) catalyst exhibits an increase of CO conversion rate from 15.6% to 29.0%, and the selectivity of C5+ hydrocarbon products still maintains at above 75%, and shows stable operation and no significant deactivation for 70 h. The above results can provide a new research idea for the development of efficient catalysts modified with nanocarbon materials in Fischer-Tropsch synthesis reaction. [ABSTRACT FROM AUTHOR]

The present work utilizes a response surface optimization technique to optimize hydrogen-rich syngas production through the process of methane dry reforming (DRM). This optimization is achieved by employing a bimetallic Mn–Ni/La 2 O 3 catalyst. The study aimed to evaluate the impact of three key parameters, namely reaction temperature, time on stream (TOS), and gas hourly space velocity (GHSV), on the hydrogen to carbon monoxide (H 2 /CO) ratio in syngas during the DRM. The Mn–Ni/La 2 O 3 catalyst, synthesized using the sequential wet impregnation technique, exhibited suitable physicochemical properties necessary for DRM reaction, as evidenced by the obtained characterization data. Among the five models examined, it was found that the quadratic versus 2FI model substantially fit the experimental data, as evidenced by a p-value <0.05. The analysis of variance (ANOVA) conducted on the quadratic response surface model compared to the 2FI model demonstrated that both the reaction temperature and the TOS had a significant impact on the H 2 /CO ratio in the syngas. The only significant interaction factor was the relationship between the reaction temperature and the TOS. Under the specified optimal circumstances of 15 000 ml/g.h, 850 °C, and 258.15 min, an H 2 /CO ratio of 0.98 was achieved. The resulting H 2 /CO ratio of 0.98 is almost 1, indicating its suitability as a feedstock for methanol production in the Fischer-Tropsch synthesis (FTS). • The Mn–Ni/La 2 O 3 catalyst exhibited suitable properties necessary for DRM reaction. • Temperature and time had a substantial impact on the H 2 /CO ratio in the syngas. • The response surface quadratic model is statistically significant to fit the experimental data. • At optimized conditions H 2 /CO ratio of 0.98 was obtained for the syngas. [ABSTRACT FROM AUTHOR]

Direct conversion of carbon monoxide into fuel through Fischer–Tropsch synthesis (FTS) is economically and environmentally beneficial as an alternative clean energy source. However, the activity and product selectivity need further investigation. In this work, a Co-MOF-71 (Co(1,4-BDC) (DMF)) was prepared solvothermally and pyrolyzed under nitrogen flow at low pyrolysis temperature to obtain a highly mesoporous Co@C-500 catalyst. The obtained catalyst exhibits high cobalt loading (53 wt%), high reducibility, optimum nanoparticle size (10.49 nm), and well-dispersed active sites. The catalytic activity of the catalyst was tested under different reaction conditions using a stainless steel fixed-bed reactor. The optimal performance showed a high CO conversion (82.7%), high C5+ selectivity (82.77%) with C5–C12 gasoline range hydrocarbons (71.9%), low C2–C4 selectivity (13%), and low methane selectivity (3.7%). Furthermore, the catalyst has a high C5+ yield of 68%, with the gasoline fraction (C5–C12) being the main product (59.1% yield). The catalyst shows superior FTS performance compared with other reported Co-containing catalysts, especially after being tested for more than 120 h without deactivation. Therefore, this work could contribute to the design of high-efficiency MOF-derived Co-FTS catalysts that could be used in the production of green and sustainable transportation fuel (gasoline). [ABSTRACT FROM AUTHOR]

During technological and social development, non-renewable sources were used to generate energy in various forms. The overexploitation of fossil fuel sources has raised significant concerns about environmental impacts. Given the need to transition to developing a more sustainable energy matrix, biofuels play an essential role as the transport sector contributes to a large percentage of gas emissions into the atmosphere. Among them, green diesel is an advanced biofuel obtained on an industrial scale, mainly by the catalytic hydrotreating of vegetable oils. In terms of technology and properties, green diesel stands out as a drop-in biofuel, which lacks blending restrictions with conventional diesel due to its chemical similarity. This biofuel also contains fewer impurities and has better combustion performance and an efficient production process. The leading green diesel manufacturing technologies are the main topic of this technological prospection review. Their particularities regarding industrial maturity are discussed, and challenges, opportunities, and drawbacks are considered and discussed for the Brazilian scenario. This analysis shows that although existing technologies have higher technological maturity, Brazil would have a special tendency toward catalytic hydrotreating for producing renewable diesel.

Power-to-Liquid processes have the potential to decarbonize maritime transport by producing carbon–neutral electro-fuels. One example of a potential implementation of this process is the combined technology of co-electrolysis of carbon dioxide and water, along with Fischer–Tropsch Synthesis. Given the promising prospects of producing electro-fuels to achieve net-zero objectives by 2050, a critical question that arises is whether sufficient resources are available to replace the current demand for fossil marine gas oil (MGO). This study evaluates the requirements and availability of resources necessary for producing marine electro-fuel using the MGO demand at the Port of Barcelona as a case study. The results indicate that current supplies of renewable energy and biogenic CO2 are insufficient to fully replace the total fossil MGO demand. However, by 2050, it is expected that these resource limitations will be overcome, considering the current official projections for the growth of renewable electricity and the biogas industry. The deployment of renewable electricity generation and the rollout of biomethane industrial network as biogenic carbon source is found to be essential for the viability of the future substitution of fossil MGO with its electro-fuel equivalent.

Abstract The investigation of the reaction's kinetics is one of the most crucial aspects of the design of a commercial process. The current research investigates the kinetics of Fischer–Tropsch synthesis using a perovskite catalyst. The LaFe0.7 Co0.3 O3 perovskite catalyst was prepared via the thermal sol–gel technique and characterized using BET, XRD, SEM, and H2-TPR techniques. According to operating conditions (e.g. H2/CO: 1–2, pressure: 10–20 barg, temperature: 240–300 °C, and GHSV: 3000 1/h), Fischer–Tropsch reaction kinetics (CO conversion) were carried out in a fixed-bed reactor. Using the framework of Langmuir–Hinshelwood–Hougen–Watson (LHHW) theories, 18 kinetic expressions for CO conversion were derived, and all were fitted to experimental data one by one to determine the optimum condition. The correlation was derived from experimental data and well-fitted using LHHW form (according to the enol mechanism, carbon monoxide and dissociated hydrogen atoms are adsorbed and reacted on the surface of the catalyst) −rCO = kpbCOPCO(bH2PH2)0.5/(1 + bCOPCO + (bH2PH2)0.5)2. Finally, the activation energy of the optimum kinetic model was determined with respect to the Arrhenius equation under various operating conditions. The activation energy of perovskite catalyst is about 106.25 kJ/mol at temperatures 240–300 °C, pressures 10–20 barg, and H2/CO ratios 1–2, which is lower than other types of catalyst. Therefore, the catalyst was activated at a high temperature and demonstrated stable performance without any temperature runaway and coking issues.

A series of supports were synthesized using two methods of sol-gel and oil-drop. In this work, the simultaneous effects of P123 surfactant, promoters (cerium, zirconium, and boron), and ethanol solvent on catalytic activity for the Fischer–Tropsch Synthesis (FTS) were studied. Cobalt catalysts were prepared using the incipient wetness impregnation method on γ-alumina granules for FTS in a fixed-bed reactor. All the prepared granules Co catalysts were characterized using FTIR, BET, XRD, TPR, FESEM, EDS, and ICP techniques. The FTS operation condition was carried out at T = 503 K, P = 15 bar, H2/CO = 2, and space velocity 5.1 NL g–1 h-1. The obtained results clearly showed that the catalytic evaluation of the Co catalysts supported on γ-alumina, with respect to the activity and selectivity of C5+ products were increased by the addition of surfactant and promoters in FTS. Also, the Co catalysts supported with γ-alumina P123 surfactant were more active than the Co catalysts supported with γ-alumina. Furthermore, the morphologies of the γ-alumina supported granules were changed by surfactant and promoters and the presence of CeO2 on the surface of the supports favors the reducibility of cobalt oxide with a shift down in reduction temperature of about 50 °C. Meanwhile, the addition the simultaneous of P123 surfactant and Ce promoter with ethanol solvent remarkably influenced the improvement of activity, selectivity, and stability of the catalyst as well. Ce promoter reduced the methane selectivity by increasing the chain-growth probability (α-value).

The current work investigated emerging fields for generating and consuming hydrogen and synthetic Fischer-Tropsch (FT) fuels, especially from detrimental greenhouse gases, CO2 and CH4. Technologies for syngas generation ranging from partial oxidation, auto-thermal, dry, photothermal and wet or steam reforming of methane were adequately reviewed alongside biomass valorisation for hydrogen generation, water electrolysis and climate challenges due to methane flaring, production, storage, transportation, challenges and opportunities in CO2 and CH4 utilisation. Under the same conditions, dry reforming produces more coke than steam reforming. However, combining the two techniques produces syngas with a high H2/CO ratio, which is suitable for producing long-chain hydrocarbons. Although the steam methane reforming (SMR) process has been industrialised, it is well known to consume significant energy. However, coke production via catalytic methane decomposition, the prime hindrance to large-scale implementation of these techniques for hydrogen production, could be addressed by coupling CO with CO2 conversion to alter the H2/CO ratio of syngas, increasing the reaction temperatures in dry reforming, or increasing the steam content fed in steam reforming. Optimised hydrogen production and generation of green fuels from CO2 and CH4 can be achieved by implementing these strategies. [ABSTRACT FROM AUTHOR]

New bifunctional cobalt catalysts for combined Fischer–Tropsch synthesis and hydroprocessing of hydrocarbons containing Pt were developed. To prepare catalysts in the form of a composite mixture, the FT synthesis catalyst Co-Al2O3/SiO2 and ZSM-5 zeolite in the H-form were used as metal and acid components, respectively, with boehmite as a binder. The catalysts were characterized by various methods, such as XRD using synchrotron radiation, SEM, EDS, TEM and TPR. The effect of the Pt introduction method on the particle size and conditions for cobalt reduction was studied. The testing of catalysts in Fischer–Tropsch synthesis was carried out at a pressure of 2.0 MPa, a temperature of 240 and 250 °C, an H2/CO ratio of 2 and a synthesis gas volumetric velocity of 1000 h−1. It is shown that the method of introducing a hydrogenating metal by adjusting the nano-sized spatial structure of the catalyst determined the activity in the synthesis and group and fractional composition of the resulting products. It is established that the presence of Pt intensified the processes of synthesis and hydrogenation, including isomeric products, and reduced the content of unsaturated hydrocarbons. The application of Pt by impregnation onto the surface of the metal component of the catalysts provided the highest productivity for C5+ hydrocarbons, and for the acidic component, it enabled maximum cracking and isomerizing abilities. [ABSTRACT FROM AUTHOR]

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For technical application with continuous operation of sorption-enhanced (SE) reactions, e.g., Fischer–Tropsch, a special reactor concept is required. SE processes are promising due to the negative effects of water on conversion and catalyst. The reactor concept of two interconnected slurry bubble columns combines the reaction with in situ water removal in the first, and sorbent regeneration in the second column with continuous exchange of slurry between the two. The liquid circulation rate (LCR) between the columns is studied in a cold flow model, measured by an ultrasonic sensor. The effects of different operating and geometric parameters, e.g., superficial gas velocity, liquid level and tube diameter on gas holdup and LCR are discussed and modelled via artificial intelligence methods, i.e., extremely randomized trees and neural networks. It was found that the LCR strongly depends on the gas holdup. The maximum of 4.28 L min−1 was reached with the highest exit, widest tube and highest superficial gas velocity of 0.15 m s−1. The influence of liquid level above the exit was marginal but water quality has to be considered. Both models offer predictions of the LCR with errors < 6%. With an extension of the models, particle circulation can be studied in the future. [ABSTRACT FROM AUTHOR]

With the depletion of petroleum resources, more and more attention has been paid to the production route of non-oil-based aviation kerosene. Among them, to produce aviation kerosene from synthesis gas (CO and H2) is one of the most promising industrial alternative fuel production routes. The traditional catalyst for making aviation kerosene from syngas is based on iron and cobalt. The process is complicated and cost is high. In this paper, a novel Co/Al-SBA-15-La metal-zeolite catalyst prepared by melt infiltration method has been reported for the direct and highly selective production of aviation kerosene components from syngas (CO and H2). Compared with the catalyst prepared by impregnation method, the Co/Al-SBA-15-La catalyst prepared by melt infiltration method has smaller, highly dispersed CoOx and LaOx nanoparticle size and suitable acidity. Under the optimal loading amount, the conversion of CO can reach 45.8%, and the selectivity of C8–C16 aviation kerosene component can reach 54.0%, which provides a new idea for the industrial production of aviation kerosene. [ABSTRACT FROM AUTHOR]

A mathematical model was constructed to estimate the performance of an MFI-membrane reactor used for Fischer–Tropsch synthesis to produce a mixture of liquid hydrocarbons. In order to accurately evaluate the reactor's performance a parametric study was performed. Under certain operational conditions, such as the total initial pressure in the reaction zone (1–4 MPa) and the hydrogen/carbon monoxide ratio (H2/CO: 1 to 2) on the performance of the studied reactor. The selectivity (productivity) of the hydrocarbon products (Si), the quantity of hydrocarbons permiated (θi) and the separation factors of each space (αi) were predicted. With increasing pressure, it is observed that θCO and θ H 2 are decreasing from 0.62 to 0.45 and from 0.55 to 0.49 respectively. However, as the H2/CO ratio rises, this measurement shows a slight increase. Aside from, the separation factors of the majority of the current species are unaffected by the H2/CO ratio increasing, while the separation factors of carbon monoxide and hydrogen are increasing. Similarly the selectivity of water, methane, carbon dioxide and ethane increases with increasing H2/CO ratio. Based on these findings it is revealed that the membrane can enable permeability for all species present in the products mixture with varying separation factors, and that the ability to separate species other than water from the reaction side is essentially non-existent. [ABSTRACT FROM AUTHOR]

A detailed operando DRIFTS study on the CO2 Fischer‐Tropsch reaction with K‐promoted Fe/YZrOx catalysts was performed to investigate the influence of this modification on the catalytic performance in the formation of lower olefins as well as higher hydrocarbons and to gain insights into mechanistic aspects. Catalytic testing revealed an enhanced formation of olefins and hydrocarbons by adding potassium to the catalysts, while spectroscopic studies revealed various stable adsorbates and intermediates such as monodentate carbonates, bicarbonates, formates, formyl, and methoxy on the surface of the K‐promoted Fe/YZrOx catalysts compared to the unpromoted one. Based on gas‐feed switching experiments and statistical analysis of literature IR data regarding Fe‐containing catalysts, it was found that carbonate species interacting with H2 are transformed to higher hydrocarbons and methane via formate and formyl formation, while bicarbonate species are decomposed accompanied by the formation of CO, which then further reacts to form formate or formyl and finally hydrocarbons. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch (FT) synthesis is an important module for the production of clean and sustainable fuels and chemicals, making it a topic of considerable interest in energy research. This mini-review covers the current literature on FT catalysis and offers insights into the primary products, the nuances of the FT reaction, and the product distribution, with particular attention to the Anderson-Schulz-Flory distribution (ASFD) and known deviations from this fundamental concept. Conventional FT catalysts, particularly Fe- and Co-based catalysis systems, are reviewed, highlighting their central role and the influence of water and water-gas shift (WGS) activity on their catalytic behavior. Various mechanisms of catalyst deactivation are also investigated, and the high methanation activity of Co-based catalysts is illustrated. To make this complex field accessible to a broader audience, we explain conjectured reaction mechanisms, namely, the carbide mechanism and CO insertion. We discuss the complex formation of a wide range of products, including olefins, kerosenes, branched hydrocarbons, and by-products such as alcohols and oxygenates. The article goes beyond the traditional scope of FT catalysis by addressing topics of current interest, including the direct hydrogenation of CO2 for power-to-X applications and the use of bifunctional catalysts to produce tailored FT products, most notably for the production of sustainable aviation fuel (SAF). This mini-review provides a holistic overview of the evolving landscape of FT catalysts and is aimed at both experienced researchers and those new to the field while covering current and emerging trends in this important area of energy research. [ABSTRACT FROM AUTHOR]

The catalyst is crucial in enhancing productivity within the Fischer-Tropsch synthesis (FTS). The metal support interaction (MSI) plays a pivotal role in the FTS catalyst performance, impacting activity, stability, and selectivity. he configuration and composition of the catalyst dramatically impact MSI, with a strong MSI (SMSI) specified for the core-shell structure. In this study, two methods consisting of chemical treatment of etching and adding a promoter (Ru) for tuning the SMSI of the FTS catalyst are presented, and their footprints on the catalysts' performance are screened by utilizing various characterization tests, molecular dynamic simulation, and catalytic tests. It is recognized that the silica interfacial perimeter acts as a barrier that restricts the charge transfer and boosts the SMSI in the silica-coated catalyst. Conversely, the etched catalyst exhibits a moderate MSI, contributing to increased reducibility, stability, and activity. Furthermore, the Ru-doped etched catalyst represents the optimum MSI, resulting in the highest overall performance. [Display omitted] • The catalyst's structure, configuration, and composition significantly affect the metal support interaction (MSI). • Chemical etching and a promoter (Ru) are used to tune the SMSI of the FTS catalyst and intensify its performance. • The etched catalyst exhibits a moderate MSI, increasing ease of reduction, stability, and activity. • The etched catalyst undergoing doping with Ru with the outer shell of ceria promotes the formation of oxygen vacancies. • Ru NPs have a significant effect on the electron charge surface density of the catalyst. [ABSTRACT FROM AUTHOR]

The investigation of the reaction's kinetics is one of the most crucial aspects of the design of a commercial process. The current research investigates the kinetics of Fischer–Tropsch synthesis using a perovskite catalyst. The LaFe0.7 Co0.3 O3 perovskite catalyst was prepared via the thermal sol–gel technique and characterized using BET, XRD, SEM, and H2-TPR techniques. According to operating conditions (e.g. H2/CO: 1–2, pressure: 10–20 barg, temperature: 240–300 °C, and GHSV: 3000 1/h), Fischer–Tropsch reaction kinetics (CO conversion) were carried out in a fixed-bed reactor. Using the framework of Langmuir–Hinshelwood–Hougen–Watson (LHHW) theories, 18 kinetic expressions for CO conversion were derived, and all were fitted to experimental data one by one to determine the optimum condition. The correlation was derived from experimental data and well-fitted using LHHW form (according to the enol mechanism, carbon monoxide and dissociated hydrogen atoms are adsorbed and reacted on the surface of the catalyst) −rCO = kpbCOPCO(bH2PH2)0.5/(1 + bCOPCO + (bH2PH2)0.5)2. Finally, the activation energy of the optimum kinetic model was determined with respect to the Arrhenius equation under various operating conditions. The activation energy of perovskite catalyst is about 106.25 kJ/mol at temperatures 240–300 °C, pressures 10–20 barg, and H2/CO ratios 1–2, which is lower than other types of catalyst. Therefore, the catalyst was activated at a high temperature and demonstrated stable performance without any temperature runaway and coking issues. [ABSTRACT FROM AUTHOR]

Catalytic syngas conversion to liquid fuel is pivotal for biomass utilization, enhancing energy security, reducing carbon emissions and curbing reliance on petroleum imports. Herein, bifunctional catalysts comprising zinc-zirconium dioxide (ZnZrO 2) dispersed on nitrogen-doped multi-walled carbon nanotubes (NCNT) (ZnZrO 2 /NCNT) were successfully designed, enabling the simultaneous production of both diesel fuels (C 9 –C 16 hydrocarbon) and methanol through direct syngas conversion. Operating at 450 °C, 4.5 MPa, a gas hourly space velocity (GHSV) of 4800 mL h−1·g cat −1, the ZnZrO 2 /NCNT catalyst, featuring 2.6% nitrogen doping, exhibited exceptional performance, achieving a 50.3% selectivity for C 9 –C 16 hydrocarbons and a 26.4% selectivity for methanol, while maintaining a 52.5% single-pass CO conversion rate. The C 9+ selectivity significantly surpasses the bottleneck predicted by the ASF distribution theory (C 9+ selectivity <36%). This starkly contrasts that of ZnO/NCNT (1.7% C 9 –C 16 and 6.3% methanol) and ZrO 2 /NCNT (32.5% C 9 –C 16 and 25.4% methanol) catalysts. Moreover, the ZnZrO 2 /NCNT catalyst still retained C 9+ 51.5% selectivity and 25% methanol selectivity after 100 h of continuous operation. The synergistic effects resulting from the amalgamation of highly active nanostructured units with a well-encapsulation structure efficiently hinder active component migration during catalysis. This significantly enhances both the catalyst's activity and stability. Furthermore, nitrogen introduction serves as a key electron donor to ZnZrO 2 , thereby catalyzing the activation of CO dissociation. This activation step emerges as a pivotal factor crucial for enhancing selectivity in liquid fuel production. [Display omitted] • Co-production of liquid fuels (C 9+) and methanol via direct conversion of syngas. • CO conversion reached 52.5% with CH 4 selectivity as low as 7.3% at 350 °C, 4.5 MPa. • ZnZrO 2 /NCNT achieved 50.3% C 9+ selectivity and 26.4% methanol selectivity. • Post 100 h, catalyst retained 51.1% C 9+ selectivity, 25% methanol selectivity. • The electron donation and basicity of NCNT account for the promotional effects. [ABSTRACT FROM AUTHOR]

In this work, cobalt catalysts based on zeolite ZSM˗5 were prepared by the triple impregnation method and chemically analyzed. Zirconium dioxide was used as a promoter (3 wt. %). Chemical analysis of the elemental composition and structure of the obtained catalysts was carried out using scanning electron microscopy. It is shown that the elemental composition of the catalysts with satisfactory accuracy corresponds to their given composition. Experiments for catalytic tests of the prepared catalysts were carried out on a laboratory Fischer-Tropsch synthesis unit and synthetic hydrocarbons were obtained. Comparative characterization of activity of the obtained catalysts with cobalt content of 10 % and 20 % has been carried out, dependence of carbon monoxide conversion and selectivity with respect to formation of gas hydrocarbons and yield of liquid products on temperature has been studied. [ABSTRACT FROM AUTHOR]

The catalytic performance of iron-based nanodispersions in Fischer–Tropsch synthesis in two different slurry reactor types, specifically a continuous stirred-tank reactor (CSTR) and a slurry bubble column reactor (SBCR), was comparatively investigated. It was found that, at equal process temperatures, the CO conversion in the SBCR using a gas disperser with four equally spaced 1-mm holes was lower than that in the CSTR. However, this observation is inconsistent with other reports in the literature. Replacing this disperser with a plate with a single centered 2-mm hole enhanced the CO conversion up to values close to those obtained in the CSTR. The reaction rate constants were calculated for the different reactor types. [ABSTRACT FROM AUTHOR]

Depletion of oil and gas resources is a major concern for researchers and the global community. Researchers are trying to develop a way to overcome these issues using the Fischer–Tropsch synthesis (FTS) process. The FTS reaction converts a mixture of hydrogen and carbon monoxide gases into a liquid fuel. The reactions are performed in the reactor and in the presence of a catalyst. A series of catalysts, such as iron, cobalt, nickel, and ruthenium, have been used for the FTS process. In iron-based catalysts, the Fe5C phase is the active phase that produces C5+ hydrocarbons. At higher conversion rates, the presence of water in the products is a problem for cobalt catalysts because it can trigger catalyst deactivation mechanisms. Ni-based catalysts play key roles as base catalysts, promoters, and photothermal catalysts in FTS reactions to produce different useful hydrocarbons. Ruthenium catalysts offer not only high activity but also selectivity toward long-chain hydrocarbons. Moreover, depending on the Ru particle size and interaction with the oxide support, the catalyst properties can be tuned to enhance the catalytic activity during FTS. The detailed reaction pathways based on catalyst properties are explained in this article. This review article describes the issues and challenges associated with catalysts used for the FTS process.