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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 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 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]

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]

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]

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]

This review focuses on the parametric impacts upon conversion and selectivity during CO 2 hydrogenation via Fischer-Tropsch (FT) synthesis using iron-based catalyst to provide quantitative evaluation. Using all collected data from reported literatures as training dataset via artificial neural networks (ANNs) in TensorFlow, three categorized parameters (namely: operational, catalyst informatic and mass transfer) were deployed to assess their impacts upon conversions (CO 2) and selectivity. The lump kinetic power expressions among literature reports were compared, and the best fit model is the one that was proposed by this work without arbitrarily assuming power values of individual partial pressure (CO and H 2). More than five sets of binary parameters were systematically investigated to find out corresponding evolving patterns in conversion and selectivity. Aided by machine learning, tailoring product distributions based on specific selectivity or conversion for optimization purpose is practically achievable by deploying the predictions generated from ANNs in this work. • The CO 2 hydrogenation via Fischer-Tropsch synthesis was reviewed rigorously. • The reported data is trained by artificial neuron networks (ANNs) for optimization. • The influential parameters were divided into three main categories. • Evolving pattens of conversion and selectivity is captured by ANNs. • Results indicates necessity of more systematic and quantitative data evaluating. [ABSTRACT FROM AUTHOR]

Fischer Tropsch synthesis (FTS) is a promising catalytic solution to achieve ultra-clean fuel in which catalyst has a significant role. Even though several kinetic models have been rendered for it, representing a new one based on a meticulous mechanism is noteworthy, particularly when employing a novel catalyst. Hence, in this work, molecular dynamic (MD) simulation is utilized to identify the appropriate pathway from the viewpoint of minimum energy of the elementary reactions. In this regard, we consider a majority of plausible FTS elementary reactions over Ru–CO@C(Z-d)@void@CeO 2 (cobalt carbon-MOF based plus ruthenium and ceria with porous structure) catalyst, and by employing MD computations forward and reverse activation energy barrier values for each reaction are evaluated. Then, based on the minimum energy pathway (MEP), the appropriate mechanism is derived, which is inferred from the H-assisted CO dissociation pathway for the beginning step. Subsequently, a kinetic model is developed based on this mechanism, and the model parameters are correlated and optimized employing the genetic and Levenberg-Marquardt algorithms, respectively. In addition, we use various statistical methods to assess the significance of the model. For instance, the Mean Absolute Percentage Deviation (MAPD) of the correlated values from the experimental value is 4.46%. Additionally, the relative residual percentage (RR%) plots illustrate that 99% of the correlated data have less than a 10% deviation. [Display omitted] • Rendering a comprehensive kinetic model based on an evaluated mechanism for Fischer Tropsch Synthesis. • Presenting a mechanism by evaluating the minimum energy pathway using Molecular dynamic computations. • Evaluating the H-assisted CO dissociation pathway meticulously. • Assessing the significance of the model employing statistical methods. [ABSTRACT FROM AUTHOR]

Syngas (a mixture of CO and H 2) has been utilized in industrial settings for the production of liquid fuels through Fischer–Tropsch (F-T) synthesis. The conventional methods of producing syngas involve energy-intensive processes utilizing coal, natural gas, or biomass. However, in order to promote more environmentally friendly practices, electrochemistry has emerged as an alternative approach. In this study, we demonstrate that syngas can be efficiently produced through electrochemical (EC) CO 2 conversion using Au-loaded perovskite strontium titanate (SrTiO 3) as a catalyst. By manipulating various parameters such as overlayer Au thickness, applied potential, electrolyte type, and concentration, we can easily control the ratio of CO to H 2. Moreover, our findings reveal that electrochemistry can directly initiate the minor channel of the F-T synthesis process. We also observe the occurrence of the EC F-T process in CO-saturated electrolyte, where CO molecules directly adsorb and interact with surface H to generate hydrocarbons. The analysis of the Anderson-Schulz-Flory equation demonstrates a strong linear relationship, confirming that the EC F-T synthesis follows the conventional F-T synthesis mechanism. This novel demonstration not only offers valuable insights into the development of EC syngas production but also enhances our understanding of the mechanism behind the formation of C 2+ hydrocarbon products. [Display omitted] • SrTiO 3 and Au-deposited SrTiO 3 electrodes were tested for Electrochemical CO 2 and CO reductions. • Tunable syngas was produced in electrochemical CO 2 reduction by varying experimental parameters. • Hydrocarbons of C n H 2n and C n H 2n+2 (up to C 7 compounds) were also produced both under CO 2 and CO condition. • Hydrocarbon production was understood by the conventional Fischer–Tropsch synthesis. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis (FTS) is a widely recognized process that catalytically converts syngas into higher hydrocarbons and oxygenates, which are ultimately upgraded into transportation fuels and chemicals. Effective temperature control and heat dissipation are crucial considerations due to the exothermic nature of the FT reaction. Underutilization of the catalytic bed is another challenge in fixed-bed reactors. The implementation of a multilayered catalytic bed, with the catalytic activity in an ascending order, has shown positive effects in addressing these issues. It mitigates adiabatic temperature rise, reduces the maximum reactor temperature, and minimizes catalyst deactivation at high temperatures. Moreover, this multilayered bed effectively addresses the underutilization issue by ensuring optimal utilization of the entire bed as the catalytic activity transitions from one layer to another during the reaction. Layers with a higher cobalt loading remain active until the completion of the reaction, resulting in minimal fluctuations in CO conversion. To achieve uniform temperature profiles, catalytic activities, and product distributions in all reactor tubes in a multitubular reactor, it is imperative to maintain consistent reaction conditions, utilize the same catalyst loading in all tubes, employ an appropriate heating system, and implement an efficient cooling system to dissipate the heat generated by the exothermic reaction. Furthermore, investigations into the properties of the used catalysts after the reaction indicate that catalyst deactivation primarily occurs due to the deposition of FT products on the catalyst surface and pores and blockage of active cobalt sites, and sintering of cobalt particles. [Display omitted] • Multilayered catalytic bed of Co/Al 2 O 3 catalysts for Fischer–Tropsch synthesis in multitubular fixed-bed reactor. • Multilayered catalytic bed reduced the maximum adiabatic temperature rise during the reaction. • Utilization of catalytic bed increase by using the multilayered catalytic bed in the reactor. • Accumulation of FT products and sintering of cobalt particles are the main catalyst deactivation mechanisms. [ABSTRACT FROM AUTHOR]

The feasibility of a renewable source for synthesis of mesoporous activated carbon (AC) as catalyst support in Fischer-Tropsch synthesis (FTS) has been investigated. For this purpose, machine learning was used to optimize the process conditions for synthesis of AC (through chemical activation) from biomass. Three different regression methods were carried out to optimize the activation time, temperature, and impregnation ratio. Random forest regression (RFR) resulted in the highest prediction accuracy with R2 of 0.88 and 0.97 for total pore volume (cm3/g) and mesoporosity (%), respectively. The prepared AC at optimum activation conditions (obtained by RFR) led to 90% mesoporosity. Prior to FT reaction, the mineral impurities of the AC were decreased using alkaline treatment. The performances of the Fe catalysts supported on AC (10Fe/AC and 20Fe/AC) were tested for FTS at 300 °C, 2 MPa, and gas hourly space velocity (GHSV) of 2000 h−1. The 20Fe/AC catalyst achieved 46.7% CO conversion and C 5+ selectivity of 72.5%, indicating the promising potential of the biomass-based catalyst support with optimized textural features and modified surface for FTS. The 20Fe/AC catalyst showed superior FT activity and C 5+ selectivity compared to the 20Fe/Al 2 O 3 , and Fe catalyst supported on commercial AC. For 20Fe/AC catalyst, liquid hydrocarbons in the range of C 5 –C 50 were detected. [Display omitted] • Activated carbon was synthesized using a lignocellulosic biomass. • Machine learning was implemented to optimize the textural properties of the activated carbon. • Alkaline treatment decreased the mineral impurities of the activated carbon. • The performance of the optimized catalyst support with 90% mesoporosity was tested in FTS. • The synthesized renewable catalyst improved the C5+ selectivity of the FTS. [ABSTRACT FROM AUTHOR]

• Ag/Cu and Cu/Ag electrodes were prepared by electrodeposition and tested for electrochemical CO 2 reduction. • Effects of the electrolyte, its concentrations, and the applied potentials were examined. • Reduction products of C 1-3 and the Fischer–Tropsch synthesis products varied substantially with experimental conditions. • Ethylene glycol was observed only over Ag/Cu electrode. • Fischer–Tropsch synthesis was explained by the *CO and *CH 2 insertion mechanism. Ag and Cu bimetallic electrodes are extensively studied for producing C-C coupled C 2+ reduction products through electrochemical CO 2 reduction. In this study, we prepared electrodes with Cu electrodeposited on Ag supports (Cu ED /Ag) and Ag electrodeposited on Cu supports (Ag ED /Cu) via electrodeposition, demonstrating behaviors for reduction products under various electrochemical conditions. The products were categorized as H 2 , C 1 (CO, CH 4 , formate, methanol), C 2 (C 2 H 4 , ethanol, acetate, acetaldehyde, glycolaldehyde, and ethylene glycol), C 3 (propanol, isopropanol), and Fischer–Tropsch (F-T) synthesis products (C n H 2n and C n H 2n+2, n ≥ 2). Notably, ethylene glycol was only observed over Ag ED /Cu. The reduction products dynamically changed with applied potentials and electrolyte concentrations. The mechanism was understood to involve surface H* adsorption, CO 2 adsorption, C-C coupling, hydrogenation, and dehydration. Minor F-T synthesis chemistry was observed, explained by *CO and *CH 2 insertion chain growth. The distinct product behaviors over the Cu ED /Ag and Ag ED /Cu electrodes provide valuable insights into the development of electrodes for producing value-added carbon products via CO 2 utilization. [Display omitted] [ABSTRACT FROM AUTHOR]

Selectively producing high-value chemicals through CO 2 hydrogenation on metal-zeolite bifunctional catalysts has garnered significant attention. In this study, we synthesized a series of bifunctional catalysts consisting of an iron-based CO 2 -Fischer-Tropsch Synthesis (FTS) component and Na-modified H-SAPO-34 zeolite, We investigated the role of zeolite acidity, the proximity of two components, and catalyst bed configuration in tailoring the product distribution and reaction pathways. The highest C 2 -C 4 olefins space-time yield (STY), reaching 18.87 mmol·g-1·h-1 (based on the quantity of iron-based component) was achieved by the physically mixed FeZnNa&Na-SAPO-2 catalyst over 100 hours time-on-stream. During the CO 2 hydrogenation reaction, the strong acidity of zeolite effectively cracked C 5+ products but also led to a decrease in O/P ratio of hydrocarbon products. The promotion of short-chain olefins, especially in the physically mixing configuration, was due to the enhanced adsorption CO intermediate on zeolite, which boosted the subsequent FTS reaction on the adjacent iron sites. In addition, Na in Na-SAPO-2 was found to be in a dynamic and active state, potentially improving the stability of the bifunctional catalyst. This study offers deep insights into designing bifunctional catalysts with a narrowed product distribution from CO 2 hydrogenation. [Display omitted] • Zeolite with strong BAS helps to narrow products distribution by cracking C 5+ products. • Na-SAPO-2 facilitate the adsorption and conversion of carbon monoxide intermediates. • The introduction of Na primarily replaces *H in the "Si-OH-Al" group in CHA cage of H-SAPO-34. • Na ions will migrate from Na-SAPO-2 to FeZnNa in FeZnNa&Na-SAPO-2 catalyst during the reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of carbon-coated alumina supports (Al 2 O 3 @C-X) with different coating properties were synthesized by modulated carbonization temperature. • The model catalysts (Co/Al 2 O 3 @C-X) have the same Co 3 O 4 particle size but differ in the cobalt-support interfacial structure. • The C-O species on the surface of the carbon layer decreased with increasing carbonization temperature. • Carbon coated Al 2 O 3 could reduce CH 4 selectivity and increase C 5+ selectivity. A series of carbon-coated alumina supports (Al 2 O 3 @C-X) with different coating properties were synthesized by modulated carbonization temperatures (600, 800, 1000, and 1200 °C, respectively) of impregnated glucose. Several model Co/Al 2 O 3 @C-X catalysts with the same Co 3 O 4 particle size but different cobalt-support interfacial structures were prepared. The effect of the cobalt-supported interface on the properties and Fischer-Tropsch synthesis (FTS) performance of the catalysts was investigated. It was found that the crystal type of Al 2 O 3 and surface oxygen-containing functional group of Al 2 O 3 @C-X were affected by carbonization temperature, thus adjusting the structural properties of the catalyst. The surface carbon layer could reduce the interaction between cobalt and Al 2 O 3 and promote the reduction of cobalt species. The stability of the catalyst depends on the nature of oxygen-containing functional groups of Al 2 O 3 @C-X. Co/Al 2 O 3 @C-1000 exhibited the best FTS performance with 34.1 % CO conversion and 62.8 % C 5+ selectivity under the reaction conditions of 230 °C, 1 MPa and 6 SL·g cat. -1·h−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structure-activity relationships at various calcination temperatures were presented. • C 5+ yield of 16.4 % with a CO 2 conversion of 34.2 % was achieved. • Different deactivation mechanisms were observed with different iron particle size. • Fe particles with 2.18 μm size were pulverized during CO 2 hydrogenation. • Fe particles with 0.52 μm size maintained its integrity during CO 2 hydrogenation. Identifying the dynamic structural evolution of iron during the thermocatalytic conversion of CO 2 into liquid hydrocarbons is a promising approach for understanding the deactivation behavior and to design an efficient catalyst. Despite the understanding of the oxidation of χ-Fe 5 C 2 to high-valent iron oxides (e.g., Fe 3 O 4 , Fe 2 O 3) caused by water formed as the byproduct, the deactivation mechanism depending on the particle size during a long-term reaction remains unclear. Herein, the structural evolution and deactivation mechanism of Na-promoted Fe 2 O 3 catalysts with varying particle sizes were investigated. The catalyst activity and deactivation behavior were highly dependent on the initial morphology of the calcined catalysts. The reduced iron catalyst with an average particle size (d ave) of 0.52 μm maintained its domain integrity, whereas that with a d ave value of 2.18 μm was severely pulverized during the CO 2 hydrogenation. The pulverized particles exposed a new surface, making it highly susceptible to re-oxidation and catalyst deactivation. Conversely, maintenance of the iron integrity suppressed the re-oxidation, whereas the excess formation of graphitic carbon on the χ-Fe 5 C 2 site was the main deactivation mechanism during long-term CO 2 hydrogenation. [ABSTRACT FROM AUTHOR]

The Co/Al 2 O 3 -CAI catalyst was successfully prepared by a coordination-assisted impregnation strategy. Compared with Co/Al 2 O 3 -EWI catalyst prepared by traditional impregnation method, the Co/Al 2 O 3 -CAI catalyst displayed superior FTS performance toward CO selectivity, high C5+ hydrocarbons selectivity, and good stability. [Display omitted] • The Co/Al 2 O 3 -CAI precursors were synthesized via a coordination-assisted impregnation strategy. • The Co/Al 2 O 3 -CAI catalyst exhibited high activity, C 5+ selectivity and stability in FTS. • More surface-exposed Co active sites contributed to the higher CO conversion. • The suitable metal-support interaction was responsible for long-term stability. Optimizing metal nanoparticle size, dispersion, accessibility, and metal-support interaction has proven impactful for Fischer-Tropsch synthesis (FTS) activity, selectivity of long-chain hydrocarbons and stability. Herein, the Co/Al 2 O 3 -CAI catalyst was successfully prepared by a coordination-assisted impregnation strategy. Compared with Co/Al 2 O 3 -EWI catalyst prepared by traditional impregnation method, the Co/Al 2 O 3 -CAI catalyst displayed superior FTS performance with a low methane selectivity (3.2 %) and surprisingly high C 5+ hydrocarbons selectivity (94.0 %) within 200 h reaction time. The catalyst remained excellent stability with ca. 40 % CO conversion even after 1600 h on stream. It revealed that the high dispersion of cobalt species as well as reduced CoAl 2 O 4 spinel could be achieved via a coordination-assisted impregnation strategy, which provide the increased number of surface-exposed Co sites. Meanwhile, the relatively strong metal-support interaction facilitated surface confinement of cobalt species and electron transfer, guarantying catalyst stability under long-term FTS process. This work provides a new insight into the design of highly efficient and stable catalysts for FTS reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Intensification of biogas to fuels process aids to break economy-of-scale barrier. • Reforming and synthesis at the same pressure avoids compression of syngas. • Process evaluated in 4 scenarios via design and TEA based on lab data. • Scenario with recycling resulted in lowest minimum fuel selling price of $4.59/gal. • >11.7 % diesel yield from biogas mass required to surpass conventional method. The Intensified Biogas to Liquid (IBGTL) process aims to overcome traditional economy-of-scale barriers in biogas-to-liquid fuel production by integrating bi-reforming and Fischer-Tropsch synthesis (FTS) in a single IBGTL reactor. This reactor operates at uniform pressure with different optimized temperatures across two zones for efficient conversion, utilizing multifunctional bi-reforming catalysts and high-temperature FTS catalysts. Bench scale experiments were carried out using landfill gas (LFG) in a single pass process, and the yield data from these experiments were fed into process scale-up design and techno-economic analysis (TEA) across four scenarios: (1) a single pass process, (2) a process with material recycling, (3) a process with liquefied petroleum gas (LPG) co-product recovery, and (4) a process with electricity generation from the fuel gas produced. TEA identified Scenario 2 as the most cost-effective, achieving a Minimum Fuel Selling Price (MFSP) of $4.59 per gallon, competitive with the current national diesel price of $4.7 per gallon. However, comparison with the conventional two-reactor system highlights the need for catalyst performance improvements. Sensitivity analysis emphasized the importance of manufacturing cost, liquid fuel yield, and biogas flow rate. Further analysis determined that the IBGTL process must achieve a diesel mass yield beyond 11.7% to surpass the economic viability of the conventional TriFTS (Tri-reforming followed by Fischer-Tropsch Synthesis) process. If the IBGTL process attains the TriFTS yield of up to 17%, the resulting MFSP could be approximately 31% lower than the current TriFTS MFSP. Renewable energy credits and carbon credits can further enhance the economic viability of BGTL processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrophobic iron-based catalysts were modified by Mg and K promoters. • Hydrophobic shell and Mg inhibit the WGS reaction and reduce the CO 2 selectivity. • The Mg modified hydrophobic catalyst has a low CO 2 selectivity of 0.89 %. • K can improve the activity of the catalyst, and the FTY value is 3017.8 μmol CO ·gFe-1·min−1. Inhibiting the occurrence of the water gas shift (WGS) reaction and reducing the selectivity of CO 2 always remained the focus of researchers in the Fischer-Tropsch synthesis (FTS) reaction. In this paper, we constructed a series of Fe-based hydrophobic core–shell FTS catalysts modified with Mg and K, successfully achieving WGS reaction suppression and reduced CO 2 selectivity. The physical structure, electronic properties, and phase composition of the hydrophobic catalyst were characterized by XRD, TEM, contact angle, H 2 -TPR, and XPS. The results demonstrated that the hydrophobic shell effectively inhibits the readsorption of the byproduct water, while Mg suppresses the formation of the active phase Fe 3 O 4 in WGS reactions. The combined effect of hydrophobic shell and Mg significantly inhibits CO 2 generation. As a result, the CO 2 selectivity of FeMg 0.1 @SiO 2 -C was only 0.89 %, which was much lower than that of the Fe 2 O 3 catalyst and the single hydrophobically modified catalyst. Additionally, the introduction of K promoted the carbonization of the hydrophobic catalyst, facilitating the improvement of the reaction activity, with an FTY value of 3017.8 μmolCO·g Fe -1·min−1 for FeMg 0.1 K-I@Si-C. [ABSTRACT FROM AUTHOR]

In this paper, a precipitated iron Fischer-Tropsch catalyst was synthesized, which is similar to commercial CNFT-1 catalyst. The effect of reaction temperature and H 2 /CO feeding ratio on the deactivation behavior were throughly investigated. The results revealed that deactivation rate was significantly affected by the reaction temperature, which showed 15 times of deactivation rate constant operated at 290 ℃ than that at 270 ℃. However, deactivation rate constant had less difference with different H 2 /CO ratio from 2 to 5. Further characterization results demonstrated that the sintering and surface oxidation of iron carbide crystallite might be the main reason responsible for the deactivation when increased the reaction temperature. An opposite effect of iron carbide oxidizing inhibition and crystallite agglomeration was observed when increasing of H 2 /CO feeding ratio, which would lead to the slight deactivation of the precipitated iron catalyst. [Display omitted] • The effect of reaction temperature and H 2 /CO ratio on F-T catalyst was investigated. • 15 times deactivation rate was obtained when operated at 290 °C than that at 270 °C. • Crystallite sintering and surface oxidation were responsible for the deactivation. [ABSTRACT FROM AUTHOR]

Light olefins such as ethylene, propylene, and butylene are key compounds in the chemical industry. Iron catalyst supported on carbon nanotubes (CNTs) is an appropriate candidate for light olefins production using synthesis gas in Fischer-Tropsch synthesis (FTS). First, catalytic chemical vapor deposition (CCVD) method was applied to synthesize CNTs using Fe/CaCO 3 and acetylene as catalyst and hydrocarbon source, respectively. Applying response surface methodology, the optimum operating conditions were determined in CVD reactor for maximal yield and purity of CNTs. The effects of reaction time (30–60 min), reaction temperature (700–800 °C), and loading of the catalyst (10–30 wt% Fe) were investigated. The synthesized CNTs was characterized by Raman spectroscopy for its graphitic structure and purity. After acid-treatment of the synthesized CNTs, Fe/CNTs-synthesized catalyst was successfully fabricated by ultrasonic-assisted wet impregnation method. 20Fe/CNTs-synthesized, 20Fe/CNTs-commercial, and 20Fe/Al 2 O 3 were analyzed in terms of physio-chemical properties and FTS catalytic performance. Comparison of transmission electron microscopy (TEM) and CO-chemisorption results showed that 20Fe/CNTs-synthesized reduces iron oxide agglomeration resulting in metal particles well-dispersed among the studied Fe-based catalysts. The catalytic performance of Fe-based catalysts was investigated using a fixed-bed reactor at 280 °C under 290 psi. 20Fe/CNTs-synthesized exhibited a lower rate of water-gas-shift (WGS) reaction compared with 20Fe/CNTs-commercial, with C 2 -C 4 selectivity of 23.6% which is slightly less than that of its commercial counterpart. Analysis of FTS liquid products revealed that 20Fe/CNTs-synthesized provides liquid hydrocarbons in the range of C 8 -C 18 , while 20Fe/CNTs-commercial and 20Fe/Al 2 O 3 obtained C 9 -C 52 and C 10 -C 20 , respectively. After 120 h time on stream under steady state condition, higher activity had been maintained by the 20Fe/CNTs-synthesized catalyst compared to the 20Fe/CNTs-Commercial and 20Fe/Al 2 O 3 catalysts. [Display omitted] • Evaluation of the effects of growth parameters on carbon nanotubes yield and purity. • High CO conversion obtained by Fe-synthesised CNTs. • Higher iron time yields obtained by Fe-synthesised CNTs. • Lighter hydrocarbons production via Fe-synthesised CNTs compared to reference catalysts. [ABSTRACT FROM AUTHOR]

Optimization of once-through three-stage Fischer-Tropsch (FT) synthesis using path optimization is performed in this study to identify optimal structure and strategies in multi-stage FT synthesis design. The study also compares three-stage designs against recycled single-stage and two-stage designs with identical residence time and outlines key differences between different plant configurations. The results showed that it is optimal to operate at the maximum possible CO conversion and as low H 2 /CO ratio as possible. The comparison of the once-through three-stage and recycled two-stage processes against recycled single-stage process showed that two-stage and three-stage processes can achieve 2.3 % and 2.7 % higher syncrude production and 2.8 % and 3.2 % higher net material value (objective function). With the possibility of recycling in all three designs, the multi-stage processes improve further: 4.2 % and 5.3 % better in terms of syncrude production and 4.2 % and 6 % better in terms of the net material value. • Systematic staging of a Fischer-Tropsch catalytic process. • Optimal process configurations and design characteristics for staged Fischer-Tropsch synthesis. • Approximately 5 % improvement in production and CO conversion with an increase in the number of stages from 1 to 3. [ABSTRACT FROM AUTHOR]

The modified alumina-supported iron-based catalysts for the direct synthesis of light olefins from syngas were prepared by incipient wetness impregnation method and tested in a fixed-bed reactor. The catalysts were characterized by H 2 -TPR, NH 3 -TPD, TEM, N 2 -physical adsorption, mercury intrusion and XRD methods. And the effects of calcination temperature of alumina supporter, iron loadings, S precursor, S/Fe molar ratio, Na/Fe molar ratio and reaction conditions on the catalytic performance were investigated. Experimental results showed that the change in calcination temperature of alumina supporter had significant influences on the structure properties and catalytic performances of the catalysts, and when the calcination temperature of alumina supporter was 1200 ºC, the catalyst exhibited the optimal catalytic performance with a CO conversion of 93.5%, a CO 2 selectivity of 24.7%, a C 2−4 olefins selectivity of 34.1% and an olefins to paraffins ratio in C 2–4 fraction of 6.7. Below 1200 ºC, strong metal-supporter interaction and surface acidity impair the catalytic performance of the catalysts; above 1200 ºC, the catalyst exhibited a poor stability. Moreover, all the S precursors were found with the ability to increase the light olefins selectivity but decrease the activity. The influence degree of these S precursors is following the order: Na 2 S > Na 2 S 2 O 3 > Na 2 SO 3 > Na 2 SO 4. The synergistic effect of Na and S promoters can optimize the catalytic performance of the catalyst. Under the reaction conditions of 340 ºC, 2.0 MPa, and 4000 h−1, the 1200 ºC-calcined alumina supported iron-based catalyst with a Na/Fe molar ratio of 0.8 and a S/Fe molar ratio of 0.02 exhibited the best catalytic performance with a CO conversion of 90.3%, a CO 2 selectivity of 27.9%, a light olefins selectivity of 47.8% and an olefins to paraffins ratio in C 2–4 fraction of 9.2. [Display omitted] • Supported iron catalyzed direct synthesis of light olefins from syngas. • The calcination of supporter significantly affected performance of the catalyst • The synergistic effect of Na and S promoters can optimize light olefins yield. • A high activity and selectivity of olefins were obtained over the modified catalyst. [ABSTRACT FROM AUTHOR]

The activity of catalysts with various sizes was compared in a fixed-bed Fischer–Tropsch reactor under similar operating conditions by determining the deactivation model. Catalyst size had no impact on the type of deactivation model. The smaller catalyst showed a smaller deactivation constant of catalyst (k d) and a lower deactivation rate in the initial stage. The decline in the activities of the catalyst with a mesh size of 40 was lower than the other catalysts, suggesting its higher long-term stability (a ss). Larger catalyst sizes led to the fouling of carbon and heavy hydrocarbons, decreasing the specific surface of the catalyst, thus increasing the pore diffusion resistance and further decrementing the catalyst activities. • Deactivation of the cobalt catalyst with various mesh sizes followed the first-order GPLE model. • Changes in the catalyst size had no impact on the type of deactivation model. • Changes in the catalyst size can alter the GPLE model parameters. • Larger catalyst sizes led to declining the catalyst activities in the first stage due to the pore diffusion resistance. • The time of the first step of catalyst deactivation increased by decreasing the size of the catalyst. [ABSTRACT FROM AUTHOR]

Scale-up of Fischer-Tropsch (F-T) synthesis using microreactors is very important for a paradigm shift in the production of fuels and chemicals. The scalability of microreactors for F-T Synthesis was experimentally evaluated using 3D printed stainless steel microreactors, containing seven microchannels of dimensions 1000 µm × 1000 µm × 5cms. Mesoporous silica (KIT-6), with high surface area, containing ordered mesoporous structure was used to incorporate 10% cobalt and 5% ruthenium using a one-pot hydrothermal method. Bimetallic Co-Ru-KIT-6 catalyst was used for scale-up of F-T Synthesis. The performance of the catalysts was evaluated and examined for three different scale-up configurations (stand-alone, two, and four microreactors assembled in parallel) at both atmospheric pressure and 20 bar at F-T operating temperature of 240 °C using a syngas molar ratio (H 2 :CO) of 2. All three configurations of microreactors yielded not only comparable CO conversion (85.6–88.4%) and methane selectivity (~14%) but also similar selectivity towards lower gaseous hydrocarbons like ethane, propane, and butane (6.23–9.4%) observed in atmospheric F-T Synthesis. The overall selectivity to higher hydrocarbons, C 5 + is in the range of 75–82% at 20 bars. A CFD model was used to investigate the effect of different design features and numbering up approaches on the performance of the microchannel reactor. The effect of the reactor inlet, the mixing internals and the channel designs on the dead zone %, the quality index factor, the cooling requirement and the maximum dimensionless temperature within the microreactor were quantified. There is no significant effect of increasing the channel width on the microreactor performance and operation of the microchannel reactor at lower Nusselt number that results in higher CO conversion. Increasing the channel width reduced the maximum temperature exhibited in the channel. Finally, the effect of increasing the y/x stacking ratio, i.e. having more reactor units in parallel compared to series, was investigated. Increasing the y/x ratio increased the cooling requirement and the maximum dimensionless temperature increase within the unit decreased the productivity. To minimize the productivity losses, numbering up in series is the better approach; however further analysis must be done to delineate heat removal requirements. [Display omitted] • 3D-printed microreactors for Fischer-Tropsch (F-T) synthesis. • Ordered mesoporous KIT-6 supported Bi-metallic Co-Ru catalyst with high surface areas. • Effect of Scalability on the performance of the catalyst. • Stability of cobalt-based bimetallic catalysts over a longer time on steam studies during F-T synthesis. [ABSTRACT FROM AUTHOR]

Different carbon nanomaterials are considered as promising supports for Fischer-Tropsch synthesis (FTS) catalysts of syngas transformation into hydrocarbons. At the same time, consolidation of carbon nanoparticles into a dense bulk material is one of the most important challenges faced by the catalytic industry. In this work consolidated Co and Fe catalysts supported on graphene nanoflakes (GNFs) were for the first time synthesized by spark plasma sintering (SPS). The synthesized catalysts contained reduced carbon-encapsulated metal nanoparticles embedded into the GNF framework, which ensured their activity in FTS without pre-activation. SPS significantly increased both the activity (from 77 to 91 µmol CO ×g Co −1 ×s−1) and TOF (from 0.024 to 0.073 s−1) of the Co/GNF catalyst compared to the unsintered sample. In contrast, the activity of the Fe catalysts decreased after SPS, but their C 5+ selectivity and olefins to paraffins ratio increased. These enhancements were attributed to the unique core-shell structure of the nanoparticles, highly active surface cobalt atoms, and close contact between carbon support and iron particles. SPS was proved to be a powerful approach to activate carbon-supported FTS catalysts, increase their density and modify their catalytic performance. [Display omitted] • FTS catalysts supported on graphene nanoflakes by spark plasma sintering. • Carbon-encapsulated Co and Fe particles embedded in nanocarbon framework. • Activity of catalysts in FTS without pre-reduction. • Increased activity of cobalt and enhanced olefin and C5+ selectivities over iron-one. • Structural transformations in iron catalyst and stability of cobalt one. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch synthesis was carried out with a ruthenium catalyst by using H 2 /D 2 switching and competitive methods. The results showed that there is an inverse isotope effect during ruthenium-catalyzed Fischer-Tropsch reactions with the hydrocarbon production rate increasing when syngas was switched to D 2 /CO. When the ruthenium-catalyzed Fischer-Tropsch synthesis was conducted using a mixture of H 2 /D 2 /CO (1:1:1) as the syngas, the H/D ratios in hydrocarbons produced by the reaction are less than 1, indicating that the deuterium was enriched in these hydrocarbons. Also, the deuterium enrichment is a function of carbon number with more deuterium enriched in larger hydrocarbons. These results are similar to the results of cobalt and iron catalyzed Fischer-Tropsch reactions we have reported earlier. To explain these results and other experimental facts accumulated over the years about Fischer-Tropsch synthesis, we proposed the alkylidene mechanism for this important reaction, in which MCH is the monomer of this polymerization-like reaction and M=CHR is the growing chain. Based on this mechanism, we developed mathematic equations for each step of propagations to calculate the deuterium enrichment. The theoretic deuterium enrichment results calculated based on the Alkylidene mechanism are very close to the experimental results of deuterium enrichment of ruthenium-catalyzed Fischer-Tropsch reactions. [Display omitted] • There is an inverse isotope effect during Ru catalyzed FT reactions. • There exist deuterium enrichments in alkanes produced by the Ru catalyzed FT reactions. • Above results can be explained by the alkylidene mechanism. • Equations derived from the alkylidene mechanism can predict the H/D ratios in alkanes incompetition experiments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Citric acid modified composite LDHs/rGO yielded uniform 3-D nanostructure. • LDH nanoflakes grew perpendicular to the graphene surface to form 3-D microstructure for better catalytic performance. • Graphene incorporation alleviated local "hot spot" of the synthesized catalyst. • This efficient catalyst yields 60 % total alcohol selectivity, with over 82 % being C 2+ alcohols. Using a citrate-assisted liquid phase co-precipitation method, a CuCoAl-LDH composite nanomaterial was successfully synthesized in situ on rGO and applied to alcohol synthesis for the first time. Structural characterization and morphological observations indicate that the hybrid material consists of hexagonal LDH nanosheets that are vertically aligned, crossed and densely distributed on the rGO surface. The graphene support significantly promoted the dispersion of LDH and prevented strong interlayer stacking during LDH crystal growth. After optimization of the Co/Cu ratio, the Cu 2 Co 1 /Al 2 O 3 /rGO catalyst exhibited a total alcohol selectivity of 60 %, of which 82 % were C 2+ alcohols, and no deactivation was observed after 100 h of reaction. The addition of the graphene support significantly reduced the particle size of the Cu-Co alloy on the catalyst surface, and the particles were highly dispersed on both the Al 2 O 3 matrix and the rGO surface. This dispersion facilitated strong interactions between the Cu-Co alloy particles, while the high thermal conductivity of graphene effectively suppressed the formation of hotspots. In addition, the well-ordered three-dimensional nanosheet structure of the LDH precursor provides a large specific surface area and highly uniformly dispersed active centers. This structure not only promotes the formation of bridge adsorption sites with high CO dissociation ability, which balances multiple bonding and bridge CO adsorption, but also significantly increases the probability of CO insertion, thereby enhancing the performance of HAS. This study provides an effective method for the preparation of LDH/rGO composites, demonstrating their broad potential application prospects. [ABSTRACT FROM AUTHOR]

Here reports the modulation of selectivity in Fischer-Tropsch synthesis through the control of cobalt reducibility within a hexagonal mesoporous silica (HMS) framework. Cobalt loading, varied from 3 % to 12.5 wt%, generated different surface and bulk cobalt species that interact variably with the support, significantly influencing their reducibility and the resultant catalytic behavior. This variation significantly affected the reducibility of the cobalt species, influencing on the catalytic behavior. The control of reducibility and stability of Co species is contingent on the cobalt loading. Higher cobalt content enhances the reducibility of Co species, shifting product selectivity from long-chain hydrocarbons to lighter olefins and oxygenates. At a TOS of 4 h, the active phase predominantly involves metallic Co species, while CO 2 and oxygenates formation is closely linked to the pair Co0-Co2+ active phase. After a TOS of 120 h, samples with higher cobalt content (6.1–15.8 % wt.) exhibited notable deactivation and changes in selectivity and hydrocarbon distribution. These changes were associated with the formation of a Co 2 C phase, which inhibits methane formation and chain growth while enhancing the production of lower olefins and oxygenates through a synergistic interaction at the Co0 and Co 2 C interface, also improves the WGS reaction, thereby increasing CO 2 selectivity. [Display omitted] • Varying Co content significantly influences the reducibility of Co species within HMS rameworks. • Changes in Co reducibility are directly linked to CO conversion, selectivity, and hydrocarbon distribution. • Higher Co reducibility boosts long-chain hydrocarbon growth; lower reducibility favors oxygenates and olefinic compound. • Reducibility degree correlates with Co species stability; lower reducibility leads to the Co 2 C phase formation. • The Co2C phase reduces CO conversion, inhibits methane formation, and suppresses growth of heavy hydrocarbons. [ABSTRACT FROM AUTHOR]

The Fischer-Tropsch (FT) synthesis, characterized by its highly exothermic and high-throughput nature, traditionally yields a mix of C 2+ hydrocarbons and C1 by-products, which adversely affect carbon utilization efficiency. Herein, we design a Fe-foam structured catalyst to selectively produce high-value olefins in FT process. The Na-Zn-Fe/Fe-foam catalysts are prepared through a hydrothermal synthesis method, where the FeC 2 O 4 precursor is formed from Fe-foam, followed by addition of sodium and zinc modifiers. These catalysts achieve a remarkable olefin selectivity of ∼80 % and a space-time yield of ∼0.70 g g cat −1 h−1 at a CO conversion of 98 %, and further demonstrate outstanding stability. The structured catalysts, with expansive void volume and fully open network architecture, provide superior mass and heat transfer capabilities, and effectively mitigate the generation of CO 2 and CH 4 , offering a significant advantage in FT synthesis. This work presents a new strategy for the development of efficient catalysts in high exothermic catalytic reactions. [Display omitted] • Na and Zn promoted Fe x O y nanocomposites grown onto Fe-foam is designed for FT synthesis. • Na-Zn-Fe/Fe-foam catalyst behaves high selectivity of value-added olefins and superior stability. • The Fe-foam-structured catalyst shows efficient mass/heat transfer than that of particulate counterpart. • Enhanced mass/heat transfer is an effective strategy to suppress C1 byproduct formation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Alkyl-tetralin sulfonate anionic surfactants synthesized using tetralin and Fischer-Tropsch synthesized α-olefins as raw materials via coal chemical route. • Structure–property relationship of alkyl-tetralin sulfonate surfactants was elucidated. • C6 alkyl-tetralin sulfonate exhibits surfactant properties comparable to commercial linear alkylbenzene sulfonate (LAS). Benzene sulfonate surfactants are crucial anionic surfactants, commonly derived from petrochemical sources. Herein, we present a new method for synthesizing alkyl-tetralin sulfonate anionic surfactants using α-olefins (n-hexene, n-octene, n-decene) and tetralin sourced from the coal chemical industry as raw materials. The three-resulting alkyl-tetralin sulfonates (C6-THNS, C8-THNS and C10-THNS), obtained by alkylation and sulfonation of tetralin were characterized through HPLC, FTIR, LCMS and 1H NMR techniques. Their surfactant properties were also investigated and compared with commercially applied linear alkylbenzene sulfonate (LAS). We observed that C6 alkyl-tetralin sulfonate (C6-THNS) exhibited smaller critical micelle concentration (CMC =0.60 mM) and lower equilibrium surface tension (γ CMC =33.43 mN/m). Similarly, C6-THNS also showed comparable foaming, wetting and emulsifying properties with LAS, which can be used as a substitute for LAS surfactants. This study shows that the synthesized alkyl-tetralin sulfonates is a potential surfactant, providing a route for efficiently using coal-based chemicals to synthesize surfactants. [ABSTRACT FROM AUTHOR]

• The interaction between Fe and Zn was tuned by changing their proximity. • The closer proximity in ZnFe 2 O 4 phase enhances the Fe-Zn interaction. • The stronger interaction of Fe and Zn is conducive to the formation and stability of Fe 2(.2) C as well as carbon deposition. • More and stable Fe 2(.2) C facilitates CO conversion, but the severer carbon deposition lead to deactivation. In the Fischer–Tropsch synthesis (FTS) reaction, the intricate reaction conditions are prone to induce phase transitions in iron carbides, which markedly affect catalytic performance. Manipulating and stabilizing the active phase is paramount for ensuring the catalyst efficiency. In this study, we regulated the Fe-Zn interaction to investigate the influence of iron carbides and the characteristics of surface carbon species. The strong interaction significantly enhanced the adsorption and dissociation of CO on the catalyst surface, thereby facilitating the formation of carbon-rich Fe 2(.2) C. Consequently, the FeZn-s catalyst exhibited the highest iron time yield (FTY) of 959 μmol CO ·g Fe -1·s-1. But meanwhile, the stronger Fe-Zn interaction also accelerated the carbon deposition rate and elevated the graphitization degree of the surface carbon, expediting the catalyst deactivation. These results provide an insight into the modulation and stabilization of iron carbides by adjusting the interaction between the Fe and supports, which inspires the further development of Fe-based catalysts for FTS applications. [ABSTRACT FROM AUTHOR]

• Converting biomass to biofuels exergetically outperforms electricity generation. • An exergoeconomic trade-off was found between exergy content products and costs. • Thermochemical routes enhanced exergy efficiency and lowered exergy costs. • Biochemical routes showed lower monetary costs and potential economic viability. • The use and better distribution of biomass leads to better biorefinery design. This work, conducted exergy and thermoeconomic analyses of sugarcane biorefineries for different biomass allocations and conversion technologies. Using the Kriging method to determine biomass allocation, this article evaluated the performance of a sugarcane biorefinery based on the 2nd Law of Thermodynamics. By this combination of techniques, it is possible to provide better guidance to decision-making. Therefore, through exergy analysis, it is possible to improve the allocation of biomass and energy resources to be more appropriate. Therefore, biorefineries can be more efficient and synthesize products at lower costs. Moreover, the highest exergy efficiency, 43.7 %, occurred when all sugarcane bagasse was destined for the thermochemical route, 60 % for Fischer-Tropsch synthesis, and 40 % for a BIG-GTCC. On the other hand, the lowest exergy efficiency, 39.63 %, was observed in the conventional case, indicating that prioritizing biomass conversion to any kind of fuel is more productive than allocating it to produce electricity in a Rankine Cycle, regardless of technology and biofuel. Moreover, from the exergoeconomic insight, a promising trade-off was determined: the thermochemical routes proved to be better in efficiency, both energetically and exergetically, while the biochemical routes, indicated potential profitability. Furthermore, the exergoeconomic analysis demonstrated that increasing the exploration of second-generation biomass in the biorefinery lowers the exergy costs of every product. Overall, this research highlights the potential associated with sugarcane biorefineries going into expansion and modernization since its resources can be valorized in terms of efficiency and monetary value. [ABSTRACT FROM AUTHOR]

Cobalt oxide (CoO) nanoparticles (NPs) were modified with different silanes (tetraethoxysilane – TEOS, triphenyl ethoxysilane – TPES, or trimethyl chlorosilane - TMCS) by dispersing the as-synthesized CoO NPs in n-hexane solutions containing the silanes. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of these silanes on the cobalt surfaces even after reduction in hydrogen (H 2) at 573 K. Modifying CoO-NPs with TEOS resulted in face-centred cubic (fcc)-cobalt phase upon reduction whereas TPES or TMCS modification induced a mixture of hexagonal close-packed (hcp)- and fcc-cobalt phases. The modification of cobalt surfaces with the silanes alters the adsorption properties of carbon monoxide (CO) on the catalytically active sites. Furthermore, temperature programmed desorption of CO (CO-TPD) showed that the amount of dissociatively adsorbed CO relative to amount of associatively adsorbed CO increases on silane-modified cobalt surfaces, which correlates with an improved rate of CO conversion in the Fischer-Tropsch CO hydrogenation. [Display omitted] • Successful modification of CoO NPs using tetraethoxysilane (TEOS), triphenyl ethoxysilane (TPES), and trimethyl chlorosilane (TMCS). • Alteration of cobalt crystalline phases upon silane modification, with TEOS inducing a face-centred cubic (fcc)-cobalt phase and TPES/TMCS leading to mixtures of hexagonal close-packed (hcp)- and fcc-cobalt phases. • Enhanced adsorption properties of carbon monoxide (CO) on silane-modified cobalt surfaces. • Improved rate of CO conversion in Fischer-Tropsch CO hydrogenation on silane-modified cobalt oxide nanoparticles. [ABSTRACT FROM AUTHOR]

Directly converting syngas to α-olefins via the Fischer-Tropsch synthesis reaction serves as a competitive alternative to the traditional petroleum route, which has attracted much recent attention. However, achieving high catalytic activity over the iron-based catalyst remains a grand challenge, due to the easy oxidation of the iron carbides active phase by the water produced during reaction. Herein, we present a porous graphite-carbon encapsulated iron-based catalyst, in which the iron carbides remain stable even under harsh reaction conditions of high CO conversion or high reaction temperature. Due to the excellent anti-oxidation ability of active phase, an ultrahigh activity for producing C 4+ α-olefins of 11.35 g·g cat −1·h−1 can be obtained. This work provides a promising strategy to develop iron-based Fischer-Tropsch synthesis catalysts with high catalytic activity and stability by rationally stabilizing iron carbides. [Display omitted] • A strategy to stabilize iron carbides during syngas to α-olefins was proposed. • Porous graphite-carbon encapsulated pure iron carbides was successfully prepared. • The rigid graphite-carbon protected iron carbides from oxidation by water. • Ultrahigh activity for producing C 4+ α-olefins of 11.35 g·g cat −1·h−1 was achieved. [ABSTRACT FROM AUTHOR]

Using coal resources to synthesize high-value surfactants is effective for clean coal utilization and low-carbon conversion, attracting more attention from academia and industry. Herein, three coal-based isomeric alkylbenzene sulfonate surfactants were successfully synthesized via sulfonation with gas phase SO 3 utilizing isomeric alkylbenzenes, derived from the alkylation of benzene and Fischer–Tropsch synthesized α-olefins, as raw materials in a microchannel reactor. Moreover, their surfactant properties were systematically investigated to reveal the structure–property relationship. The results indicated that the equilibrium surface tension (γ CMC) for the synthesized surfactants was reduced with the increase of the degree of hydrophobic tails branching, and the order of γ CMC was: sodium dodecylbenzene sulfonate (35.67 mN·m−1) > sodium C6 olefin dimer alkylbenzene sulfonate (34.18 mN·m−1) > sodium dihexylalkylbenzene sulfonate (29.94 mN·m−1). Sodium dihexylalkylbenzene sulfonate with the lower γ CMC exhibited superior wettability (the contact angle of 50.2 ° at 30 s) and excellent emulsifying capacity (emulsification time of 1337 s) at the corresponding critical micelle concentration. This study provides new insights into rational design of hydrophobic tail architectures of surfactant molecules to meet specific needs in various fields. [Display omitted] • Isomeric alkylbenzene sulfonate surfactants with same carbon numbers were successfully synthesized via coal chemical route. • Isomeric alkylbenzene sulfonates with different hydrophobic tail architectures exhibited varied surfactant properties. • New insights into rational design of surfactant molecules with hydrophobic tail architectures for specific needs. [ABSTRACT FROM AUTHOR]

[Display omitted] • Machine learning model (ANN) was trained to estimate the performance of Fischer–Tropsch synthesis perfectly. • The effect of different parameters such as temperature, pressure, H 2 /CO, and space velocity on CO conversion and products selectivity was studied. • Genetic Algorithm optimization technique was applied to maximize the selectivity of liquid fuel by manipulating the operating parameters. This study aimed to increase liquid fuel (C 5+) product selectivity from CO and H 2 conversion over a Cu/Fe-based catalyst and followed by artificial neural network simulation to enable a profound visualization strategy for Fischer–Tropsch (FT) process. The experiments were performed in a fixed-bed reactor over temperatures (T) of 483–553 K, pressures (P) of 14.5–203 psig, space velocities (SV) of 1000–2900 hr−1, and H₂/CO feed ratios of 1–6.2. Mathematical modeling (MM) and artificial neural network (ANN) were utilized to simulate the nonlinear CO conversion and product selectivity of the FT process. Nine simultaneous reaction pathway was developed to evaluate the reactant and product behaviors under varying FT conditions. In addition, a multilayered parameter processed by a neural network was used to predict the performance of the CO hydrogenation process. A comparison between these two approaches demonstrated that ANN more closely mimicked the nonlinear conversion and selectivity of the FT process than MM, and the correlation coefficients for the predicted mole fractions and CO conversion were 0.991 and 0.986, respectively. A hybrid Genetic Algorithm–ANN procedure was constructed to predict the optimum operating conditions to increase liquid fuel over the catalyst. The optimum C 5+ selectivity (75.1 %), which meets the FT process objective, was achieved under operating conditions of T = 483 K, P = 203 psig, SV = 1303 hr−1, and H₂/CO feed ratio = 1.01 for process design optimization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Investigation of promoter type and its composition on the light olefin production via Fischer-Tropsch Synthesis (FTS). • Evaluating designated catalyst performances by computational approaches: Response Surface Methodology (RSM) and Artificial Neural Network (ANN). • Both methods create promising models for light olefin production via FTS based on MSE and R2. • Ho, Cu and Zn promoters were found to have a positive effect on light olefin production. • 0.5Ho10Fe2Co/α-Al 2 O 3 catalyst attained the highest light olefin production among a total of 49 designated catalysts. The production of light olefins via Fischer-Tropsch Synthesis (FTS) was investigated by both experimental and modeling studies. Experimental studies were conducted by employing promoted FeCo/α-Al 2 O 3 (FeCo) bimetallic catalysts. The Response Surface Methodology (RSM) and Artificial Neural Network (ANN) methods were used in modeling. Specifically, effects of the types and concentration of promoters on the catalytic performances of α-Al 2 O 3 supported iron-cobalt bimetallic catalysts are investigated by using Ce, Ni, La, Ho, Ga Cu, Mn, and Zn used as promoters. A total of 49 catalysts were prepared by co-impregnation method and tested at 310 °C and 1 bar in a high-speed catalyst performance test system (HT-CPA). The FTS performances of catalysts showed that both the types and amounts of the promoters can affect light olefin production. The light olefin (C 2 =–C 3 =) production of unpromoted FeCo catalyst was about 3.87 × 10−3 (mol C/g active metal. h). The best performances were obtained from FeCo catalysts promoted with Ho, Cu, and Zn. Presence of these promoters increased olefin production up to ∼ 84 %, 76 % and 70 %, respectively. Performance parameters (MSE and R2) of RSM and ANN models revealed that both methods can be used to support experimental studies and provide a procedure for optimizing catalyst formulations yielding the desired product selectivity in FTS processes. The RSM outcomes aligned with experimental findings, suggest that that Ho, Cu, and Zn can serve as suitable promoters for the light olefin production in FTS. ANN model attained higher performance parameters (R2 = 0.95 and MSE = 2E−7) than RSM model (R2 = 0.85 and MSE = 3.4E−7). This indicates that ANN model, which designed as one hidden layer including 7 neurons, can provide better predictions and a fitting capacity. Therefore, it may be used in further optimization and sensitivity analysis approaches. Alignment degree between the experimental and modeling results demonstrates that the proposed methodology can provide a reliable and efficient way to guide experiments to optimize catalyst formulations through identification of potential promoters and their amounts to be used. [ABSTRACT FROM AUTHOR]

This work provides a comprehensive techno-economic assessment of high-temperature direct air capture (HTDAC) integrated with Fischer–Tropsch synthesis (FTS) for producing renewable jet fuel on a scale of approximately 25 t/h. Specifically, the HTDAC is based on calcium looping employing calcination in a hydrogen-based atmosphere to enable simultaneous RWGS reaction. A detailed description of the Aspen Plus model for HTDAC, alkaline and solid oxide electrolysis systems, RWGS reactor and the FTS is provided for future reference. Five system configurations are analysed, comparing the energy efficiency effects of hydrogen oxy-fuel combustion and electric calcination in a hydrogen-based atmosphere. In this regard, the potential omission of the RWGS reactor is examined, considering that 62 to 78 % of the CO 2 is already converted into CO in the calciner, with the highest conversion rates achieved through electric calcination. Moreover, the study investigates the impact of alkaline electrolysis and solid oxide electrolysis on the system's energy efficiency. Overall carbon efficiencies of more than 50 % in the jet fuel are achieved, with system energy efficiencies ranging from 30.6 to 39.0 % corresponding to fuel-specific energy consumption in the range of 122 to 156 MJ/kg Jet fuel. Net present value (NPV) analysis reveals a projected minimum fuel selling price (MFSP) in the range of 4.45 to 6.32 €/L, which is significantly higher than previous literature estimates based on more optimistic cost assumptions. Uncertainties in cost parameters are addressed through a Monte Carlo analysis which shows the potential of a significant decrease in the MFSP provided that some of the cost estimates will be cheaper than the conservative initial estimate. Conclusively, this study highlights the significance of developing a financially feasible electrically heated calciner that can effectively handle high-temperature hydrogen. Furthermore, maximising the yield of jet fuel emerges as a critical factor for unlocking the future potential of the process, as it substantially reduces the cost of fuel production. Lastly, the reduction of hydrogen production costs is identified as the most crucial aspect in enhancing the economic viability of the process, as it serves as the biggest contributor to the high minimum fuel selling price. • Comparison of 5 integrated direct air capture, Fischer–Tropsch, and electrolysis systems. • Potential integration of H 2 -fired calciner and RWGS in single component is discussed. • Jet fuel energy efficiency up to 39 %; potential for 47 % with lights and waxes. • Minimum jet fuel selling price: 3.5–6.5 €/L with H 2 as main cost contributor. • Electric calcination in H 2 reduces the minimum jet fuel selling price with ∼ 0.6 €/L. [ABSTRACT FROM AUTHOR]

This study explores electrochemical Fischer–Tropsch (EC F-T) synthesis as an eco-friendly approach for liquid fuel production, departing from conventional energy-intensive methods. While EC syngas generation is well-explored, the synthesis of F-T chemistry using CO 2 and CO feed gases remains relatively unexplored. Investigating various transition metals, including Ti, Zr, V, Mo, Fe, Co, Ni, Pd, Cu, Ag, Au, Zn, and Cd, we present compelling evidence of F-T chemistry, yielding long-chain hydrocarbons (C n H 2n and C n H 2n+2 , n=2–7), with Zn being an exception. This breakthrough involves surface C-C coupling chain growth, resembling traditional F-T synthesis, incorporating *CO and *CH x insertion reactions. Density of states and energy states near the Fermi level were analyzed. The experimental framework enhances our understanding of C-C coupling mechanisms, offering insights into environmentally friendly EC methods for long-chain hydrocarbon production and advancing innovative strategies in sustainable F-T synthesis for future energy solutions. [Display omitted] • Fischer-Tropsch (F-T) chemistry was commonly observed across all transition metals in electrochemistry except for Zn. • Au exhibited the highest F-T activity in CO 2 -rich conditions. • Co and Cu displayed enhanced F-T activity in CO-rich environments. • The linearity of ASF plots supports conventional F-T synthesis mechanisms. • Cu demonstrated deviations from linearity in the production of CH 4 and C 2 H 4. [ABSTRACT FROM AUTHOR]

• Achieving CoFe alloy & Co + Fe 2 C in Co-Fe bimetallic catalysts by a strategic precursor addition. • Ensuring consistent metal size and support properties for each catalyst. • Investigating the performance mechanism of three active phases in FTS. • Leveraging Co-Fe interaction in CoFe alloy to optimize CO/H 2 adsorption behaviors. • Enhancing FTS performance through increased strongly adsorbed CO and improved CO/H 2 ratio. In the realm of Fischer-Tropsch synthesis (FTS), the escalating cost of cobalt has spurred interest in Co-Fe bimetallic catalysts as substitutes for monometallic Co catalysts. Unfortunately, it is difficult to clarify specific functions and interactions of the two phases, as investigating catalysts in a unified dimension of both metal and support is still a challenge. Herein, we realize precise control over synthesizing nitrogen-doped carbon materials supported bimetallic catalysts containing CoFe alloy and Co + Fe 2 C dual active phases. The catalysts are comprehensively characterized to address the above problem by excluding the influence of metal sizes and support properties. Our findings reveal that compared to metallic Co alone and Co + Fe 2 C dual active phases, the Co-Fe interaction in CoFe alloy with electron transfer from Fe to Co optimizes reactant adsorption behaviors through achieving a larger number of strongly adsorbed CO per active site to increase the density of C* adsorbates and a higher surface CO/H 2 ratio to inhibit the hydrogenation of CH x * intermediates for chain termination, as well as an appropriate ability for CO adsorption/ dissociation. These advantages collectively enhance both CO activation and C-C coupling, and consequently, the CoFe/NC (CoFe alloy) catalyst exhibits the superior catalytic performance in the cobalt space–time yield in C 5+ products (3011.2 g C5+ kg Co −1h−1), which surpasses the Co/NC (monometallic Co) and Co + Fe/NC (Co + Fe 2 C dual active phases) by 2.2 times and 2.4 times, respectively. This study serves as a promising route for the development of efficient and low-cost bimetallic catalysts through the strategic arrangement of multiple active phases for various reactions. [ABSTRACT FROM AUTHOR]

This study aims to evaluate and compare two integrated processes (Plant A and B) for hydrocarbon production from CO 2. They involve proton exchange membrane water electrolysis for H 2 production, reverse water-gas shift reaction for syngas production, pressure swing adsorption for syngas purification, Fischer-Tropsch synthesis for diesel-range hydrocarbons from CO 2 , and atmospheric distillation for product separation. Plant B additionally integrates a hydrocracking-based upgrading section. The simulations were performed using Aspen Plus® v10, Aspen Adsorption® v10, and Aspen Custom Modeler® v10. The evaluation covers technical, economic, environmental, and multi-criteria assessment (GREENSCOPE). The proposed processes demonstrate the potential to convert CO 2 to hydrocarbons, with carbon conversion rates of 75% and 71% for Plants A and B, respectively. Process energy intensity is 155 and 170 MJ/kg LP for Plants A and B, respectively. Environmental assessment reveals CO 2 reduction, resulting in negative global warming potentials of −2.20 and −0.84 kgCO 2-eq /kg LP for Plants A and B, respectively. The sustainability degree indices for Plants A and B are 1.00 and 0.06, respectively, indicating Plant A as the more sustainable process alternative based on both quantitative and qualitative metrics. Economic analysis shows project unviability in the Brazilian context due to reliance on H 2 production and prevailing pricing conditions. Economic viability requires a price increase of liquid products by 266% and 302% or CO 2-eq abatement costs ranging from 2.05 to 3.43 US$/kgCO 2-eq for Plants A and B, respectively. GREENSCOPE methodology indicates better performance for Plant A across all scores, highlighting a clear connection between the hydrocracking unit and performance indicators. The findings show that these processes align with sustainable development goals (SDGs) targets for climate action (SDG 13), clean energy (SDG 7), industry, innovation, and infrastructure (SDG 9), decent work and economic growth (SDG 8), and responsible consumption and production (SDG 12). Overall, the research moves forward SDGs by offering solutions to cut carbon emissions and promote sustainable industrial practices. [Display omitted] • The overall carbon conversion achieved 71–75%. • The global warming potential is about −2.20 to −0.84 kg CO2-eq /kg LP. • The net present value is about −1066 to −1147 MMUS$. • An increase of 266–302% in liquid product prices is required for economic viability. • A CO 2-eq abatement cost of 2.05–3.43 US$/kg is required for economic viability. [ABSTRACT FROM AUTHOR]

Electro-synthetic fuel is proposed as an approach to achieve net-zero carbon emissions for heavy-duty internal combustion engines and meet carbon neutrality targets. This method is based on high temperature co-electrolysis using a solid oxide electrolysis cell (SOEC) coupled with Fisher-Tropsch (FT) synthesis due to its high efficiency and carbon recycling capacity. To access the techno-economic viability of this pathway and identify the key elements impacting the cost of electro-synthetic fuels, a comprehensive techno-economic model is constructed. This model aims to offer cost cutting guidance and includes SOEC, FT, and techno-economic sub-models, with SOEC and FT validated using literature data. The cost breakdown and sensitivity analysis indicate that heating costs, electricity prices, and stack lifetime are critical factors in reducing the cost of electro-synthetic fuel. Three alternative system layouts that fully utilize thermal and chemical energy are proposed to address the significant heating expense issue. Among these, the optimal system design lowers costs by approximately 5.3 %. Furthermore, this work introduces the contradiction between high performance, high stability, and low-cost accounting for the SOEC lifetime, which is bounded by operating current density. When considering the degradation and replacement of SOEC stacks, the long-term profitability of operating SOEC at a current density of 500 mA/cm2 is superior to that of 850 mA/cm2. Despite the most effective layout being currently unprofitable, it is anticipated that in the future, carbon trade, renewable electricity and technological advancements will drive the cost of electro-synthetic fuel to become competitive with that of diesel. • A techno-economic model based on SOEC coupled with FT process is developed. • SOEC degradation effects on product cost is considered in TEA model. • Layouts with energy recycling are proposed with best case to reduce cost by 5.3 %. • Electro-synthetic fuel will be competitive as green electricity costs decrease. [ABSTRACT FROM AUTHOR]

• Carbon deposition in the Co-catalyzed FTS is sensitive to the crystal phase of Co catalyst. • HCP Co is revealed to present much higher anti-carbon deposition stability than FCC Co. • The higher stability of HCP Co is attributed to its much denser active sites with B 5 -type active unit. • HCP Co exhibits better surface C deactivation resistance ability via surface C hydrogenation. • HCP Co with (10–10), (10–12) and especially (10–11) facets can achieve high stability and activity. A very challenging issue with Co-catalyzed FTS, surface carbon deposition and thus FTS catalyst deactivation, remains unresolved for many years. This research is designed to overcome the challenge by using theoretical calculations together with the FTS experiments. Our theoretical calculations for the first time reveal that HCP Co not only have much higher anti-carbon deposition stability but also exhibits a better anti-carbonization capability than FCC Co; the higher stability of HCP Co is attributed to its much denser active sites with the step B 5 -type active unit to eliminate surface carbon species. Our FTS experiments confirm the theoretical calculation results. The great dependence of anti-carbon deposition stability on the crystallographic structure and morphology of the catalysts revealed here may open a new avenue for better, stable catalysts with maximum mass-specific reactivity. [ABSTRACT FROM AUTHOR]

Fischer-Tropsch Synthesis (FTS) allows the conversion of syngas to high-density liquid fuels, playing a key role in the petrochemical and global energy sectors over the last century. However, the current Global Challenges impose the need to recycle CO 2 and foster green fuels, opening new opportunities to adapt traditional processes like FTS to become a key player in future bioenergy scenarios. This review discusses the implementation of CO 2 -rich streams and in tandem catalysis to produce sustainable fuels via the next generation of FTS. Departing from a brief revision of the past, present, and future of FTS, we analyse a disruptive approach coupling FTS to upstream and downstream processes to illustrate the advantages of process intensification in the context of biofuel production via FTS. We showcase a smart tandem catalyst design strategy addressing the challenges to gather mechanistic insights in sequential transformations of reagents in complex reaction schemes, the precise control of structure-activity parameters, catalysts aging-deactivation, optimization of reaction parameters, as well as reaction engineering aspects such as catalytic bed arrangements and non-conventional reactor configurations to enhance the overall performance. Our review analysis includes technoeconomic elements on synthetic aviation fuels as a case of study for FTS applications in the biofuel context discussing the challenges in market penetration and potential profitability of synthetic biofuels. This comprehensive overview provides a fresh angle of FTS and its enormous potential when combined with CO 2 upgrading and tandem catalysis to become a front-runner technology in the transition towards a low-carbon future. [ABSTRACT FROM AUTHOR]

ZIF-67 derived catalysts for Fischer-Tropsch synthesis have attracted much attention in recent years, while there is still a potential to improve their activity and selectivity. In this work, we prepared Si/Al co-immobilized Co 3 O 4 @Si x Al y catalysts by in-situ doping tetraethylorthosilicate and aluminum nitrate during the synthesis of ZIF-67. The effects of different Si/Al ratios on the metal-support interaction, acidity and FTS performance were explored. Results indicated that the Co 3 O 4 @Si 0 Al 4 catalyst exhibited the best FTS performance with the CO conversion as high as 79.9% and CTY (cobalt time yield) value of 19.5 × 10−5 mol CO ·g Co −1·s−1, which was ascribed to the moderate metal-support interaction and the most active Co sites. Meanwhile, the Co 3 O 4 @Si 3 Al 1 and Co 3 O 4 @Si 2 Al 2 catalysts exhibited higher iso-paraffin and olefin selectivity due to more acidic sites. The Co 3 O 4 @Si 0 Al 4 catalyst exhibited the highest FTS activity due to the moderate metal-support interaction (MSI), while the Co 3 O 4 @Si 3 Al 1 and Co 3 O 4 @Si 2 Al 2 catalysts showed certain hydrocracking and isomerization ability due to the formation of acidic sites. [Display omitted] • Co 3 O 4 @Si x Al y catalysts were prepared by in-situ doping method based on ZIF-67. • The Co 3 O 4 @Si 0 Al 4 exhibited the highest Fischer-Tropsch synthesis (FTS) activity. • The high activity was due to moderate metal-support interaction and most active sites. • Acidic sites promoted the hydrocracking and isomerization of long chain hydrocarbons. [ABSTRACT FROM AUTHOR]

For the future energy markets, where the role of fossil fuels will be minimized and district heating systems will become more efficient through the use of waste streams, a new concept is proposed based on tri-generation of Fischer–Tropsch (FT) products, heat, and power. The challenge of combining the transport sector with a District Heating (DH) network and power grid is presented in this article by discussing the operating modes of the gasifier, FT product output (as a raw material for refinery) and waste stream generated after the synthesis reactor, preliminary process management schemes, market factors, and economic attractiveness. The feasibility of the concept was examined for an existing combined heat and power plant in Lithuania, which could become a potential demo plant. To demonstrate the feasibility of this concept, which may help create independence from fossil fuels through the use of syngas (for a sudden increase in heat demand), a techno-economic assessment was performed. The analysis of various scenarios showed that the cost of the FT product may be between 0.67 and 1.47 €/kg for gasifier capacities ranging from 10 to 40 MW. However, the economic attractiveness assessment revealed that the concept is profitable at a liquid biofuel (FT product) prime cost below 1.07 €/kg (without electrolysis capability). [ABSTRACT FROM AUTHOR]