Search Results (39)

Low-temperature Fischer–Tropsch (LTFT) synthesis converts syngas to diesel/wax at 200–250 °C. The LTFT reaction has recently received renewed interest, as it can be used for converting syngas from renewable sources (biomass and waste) to high-value fuels and chemicals. Conventional LTFT reactors, such as fixed-bed and slurry reactors, are not entirely suitable for bio-syngas conversion due to their smaller scale compared to fossil fuel-based syngas processes. This review explores advancements in intensifying LTFT reactors suitable for bio-syngas conversion, enabling smaller scale and dynamic operation. Various strategies for enhancing heat and mass transfer are discussed, including the use of microchannel reactors, structured reactors, and other designs where either one or both the heat and mass transfer are intensified. These technologies offer improved performance and economics for small LTFT units by allowing flexible operation, with increased syngas conversion and reduced risk of overheating. Additionally, this review presents our outlook and perspectives on strategies for future intensification. Full article

The production of Fischer–Tropsch liquid biofuels from the supercritical water gasification (SCWG) of lignocellulosic biomass is energetically and environmentally assessed by coupling process modelling with Life-Cycle Assessment. A conceptual process model has been developed comprising the following stages: (a) the thermochemical conversion of lignocellulosic biomass in a supercritical water gasification (SCWG) reactor, (b) syngas upgrade through dry reforming (DRR), (c) liquid biofuel production from Fischer–Tropsch synthesis (FTS) and (d) FT product upgrade and refinement, so that diesel-like (FT—Diesel), gasoline-like (FT—Gasoline), and jet fuel-like (FT Jet Fuel) yields are predicted. Parametric studies have been performed, highlighting the effect of biomass concentration and SCWG temperature on end-product yields. Furthermore, alternative scenarios have been examined with respect to: (a) maximizing FT liquid biofuel yields and (b) minimizing heat requirements to potentially achieve a thermally self-sustained process. The results of the simulated process, including liquid biofuel yield and heat-demand predictions, are used as inputs in the inventories compiled for the Life-Cycle Assessment of the overall process. Agricultural and feedstock transportation stages have also been considered. Energetic and environmental benefits and challenges are highlighted through the quantification of Global Warming Potential (GWP), while special importance is assigned to following the REDII sustainability methodology and reference data. Full article

The main goal of this research is the production of e-fuels in gasoline- and diesel-range hydrocarbons via the hydrocracking of wax from Fischer–Tropsch (FT-wax) synthesis. The hydrogen for the hydrocracking process originated from solar energy via water electrolysis, thus, the produced fuels were called e-fuels. The FT-wax was produced via the Fischer–Tropsch synthesis of syngas stream from the chemical looping gasification (CLG) of biogenic residues. For the hydrocracking tests, a continuous-operation TRL3 (Technology Readiness Level) pilot plant was utilized. At first, hydrocracking catalyst screening was performed for the upgrading of the FT-wax. Three hydrocracking catalysts were investigated (Ni-W, Ni-W zeolite-supported, and Ni-W Al₂O₃-supported catalyst) via various operating conditions to identify the optimal operating window for each one. These three catalysts were selected, as they are typical catalysts that are used in the petroleum refinery industry. The optimal catalyst was found to be the NiW catalyst, as it led to high e-fuel yields (38 wt% e-gasoline and 47 wt% e-diesel) with an average hydrogen consumption. The optimum operating window was found at a 603 K reactor temperature, 8.3 MPa system pressure, 1 hr⁻¹ LHSV, and 2500 scfb H₂/oil ratio. In the next phase, the production of 5 L of hydrocracked wax was performed utilizing the optimum NiW catalyst and the optimal operating parameters. The liquid product was further fractionated to separate the fractions of e-gasoline, e-diesel, and e-heavy fuel. The e-gasoline and e-diesel fractions were qualitatively assessed, indicating that they fulfilled almost all EN 228 and EN 590 for petroleum-based gasoline and diesel, respectively. Furthermore, a 12-month storage study showed that the product can be stored for a period of 4 months in ambient conditions. In general, green transportation e-fuels with favorable properties that met most of the fossil fuels specifications were produced successfully from the hydrocracking of FT-wax. Full article

Nowadays, transportation fuels such as diesel or gasoline are standardly produced from crude oil refining. These petroleum-based products are gradually replaced by more environmentally friendly sources, such as Fischer–Tropsch diesel fractions and other biofuels. The present work reports the distillation of Fischer–Tropsch (FTS) waxes and its use for fuel production by (i) blending the FTS wax diesel fraction with fossil diesel (7:93; 15:85; 30:70; and 50:50 wt.%) and (ii) blending the FTS wax heavy fraction (360–700 °C) with vacuum gas oil (10–50 wt.%) followed by hydrocracking at industrial operating conditions (T = 420 °C, WHSV = 0.5–1.0 h⁻¹, P = 10.0 MPa). The obtained products in both cases were analysed and compared with standard EN590 for petroleum-diesel fuels. Overall, our results point to the suitability of the distillation of FTS waxes for renewable fuel production, either by straight blending of the diesel petroleum-based products or co-hydrocracking of the heavy fraction with vacuum gas oil. Full article

A techno-economic assessment and environmental and social sustainability assessments of novel Fischer–Tropsch (FT) biodiesel production from the wet and dry gasification of biomass-based residue streams (bark and black liquor from pulp production) for transport applications are presented. A typical French kraft pulp mill serves as the reference case and large-scale biofuel-production-process integration is explored. Relatively low greenhouse gas emission levels can be obtained for the FT biodiesel (total span: 16–83 g CO₂eq/MJ in the assessed EU countries). Actual process configuration and low-carbon electricity are critical for overall performance. The site-specific social assessment indicates an overall positive social effect for local community, value chain actors, and society. Important social aspects include (i) job creation potential, (ii) economic development through job creation and new business opportunities, and (iii) health and safety for workers. For social risks, the country of implementation is important. Heat and electricity use are the key contributors to social impacts. The estimated production cost for biobased crude oil is about 13 €/GJ, and it is 14 €/GJ (0.47 €/L or 50 €/MWh) for the FT biodiesel. However, there are uncertainties, i.e., due to the low technology readiness level of the gasification technologies, especially wet gasification. However, the studied concept may provide substantial GHG reduction compared to fossil diesel at a relatively low cost. Full article

Lignocellulosic and waste materials, such as sewage sludge, can be broken down into its useful constituents and converted into fuel for engines. This paper investigates microwave pyrolysis to decompose biomass into H₂ and CO (syngas), which may be catalysed in the Fischer–Tropsch (F-T) process to liquid biofuels. Using microwave radiation as the heat source for pyrolysis proves to yield large quantities of gas with higher concentrations of H₂ and CO compared to conventional heating methods. This is largely due to the energy transfer mechanism of microwaves. Pyrolysis parameters such as temperature (which increases with input power), feedstock type, microwave absorber, and biomass moisture content influence syngas yield. Several papers reviewed for this study showed differing optimal conditions for microwave pyrolysis, all being heavily dependent on the biomass used and its composition. However, all researchers agreed on the thermal efficiency of microwave heating and how its material-selective nature can increase syngas yield. Compared to diesel fuels (while processing a similar efficiency and a higher cetane number), FT fuels and specifically pyrolysis may yield the benefit of reduced nitric oxides (NOx), particulate matter (PM), unburnt hydrocarbons (HC) and carbon monoxide (CO) emissions. Full article

The production of sustainable, biomass-based synthetic natural gas (SNG) and Fischer–Tropsch (FT) diesel can contribute significantly to climate neutrality. This work aims to determine the commercial-scale production costs and CO₂ footprint of biomass-based SNG and FT diesel to find suitable integration scenarios for both products in the Austrian energy system. Based on the simulation results, either 65 MW SNG and 14.2 MW district heat, or 36.6 MW FT diesel, 17.6 MW FT naphtha, and 22.8 MW district heat can be produced from 100 MW biomass. The production costs with taxes for wood-based SNG are 70–91 EUR /MWh and for FT diesel they are 1.31–1.89 EUR /L, depending on whether pre-crisis or crisis times are considered, which are in the range of fossil market prices. The CO₂ footprint of both products is 90% lower than that of their fossil counterparts. Finally, suitable integration scenarios for SNG and FT diesel in the Austrian energy system were determined. For SNG, use within the energy sector for covering electricity peak loads or use in the industry sector for providing high-temperature heat were identified as the most promising scenarios. In the case of FT diesel, its use in the heavy-duty traffic sector seems most suitable. Full article

The Fischer–Tropsch process is considered one of the most promising eco-friendly routes for obtaining synthetic motor fuels. Fischer–Tropsch synthesis is a heterogeneous catalytic process in which a synthesis gas (CO/H₂) transforms into a mixture of aliphatic hydrocarbons, mainly linear alkanes. Recently, an important direction has been to increase the selectivity of the process for the diesel fraction. Diesel fuel synthesized via the Fischer–Tropsch method has a number of advantages over conventional fuel, including the high cetane number, the low content of aromatic, and the practically absent sulfur and nitrogen impurities. One of the possible ways to obtain a high yield of diesel fuel via the Fischer–Tropsch process is the development of selective catalysts. In this review, the latest achievements in the field of production of diesel via Fischer–Tropsch synthesis using catalysts are reviewed for the first time. Catalytic systems based on Al₂O₃ and mesoporous silicates, such as MCM-41, SBA-15, and micro- and mesoporous zeolites, are observed. Together with catalytic systems, the main factors that influence diesel fuel selectivity such as temperature, pressure, CO:H₂ ratio, active metal particle size, and carrier pore size are highlighted. The motivation behind this work is due to the increasing need for alternative processes in diesel fuel production with a low sulfur content and better exploitation characteristics. Full article

Artificial fuels have been researched for more than a decade now in an attempt to find alternative sources of energy. With global climatic conditions rapidly approaching the end of their safe line, an emphasis on escalating the change has been seen in recent times. Synthetic fuels are a diverse group of compounds that can be used as replacements for traditional fuels, such as gasoline and diesel. This paper provides a comprehensive review of synthetic fuels, with a focus on their classification and production processes. The article begins with an in-depth introduction, followed by virtually classifying the major synthetic fuels that are currently produced on an industrial scale. The article further discusses their feedstocks and production processes, along with detailed equations and diagrams to help readers understand the basic science behind synthetic fuels. The environmental impact of these fuels is also explored, along with their respective key players in the industry. By highlighting the benefits and drawbacks of synthetic fuels, this study also aims to facilitate an informed discussion about the future of energy and the role that synthetic fuels may play in reducing our reliance on fossil fuels. Full article

The interest in Gas-to-Liquid technology (GTL) is growing worldwide because it involves a two-step indirect conversion of natural gas to higher hydrocarbons ranging from Liquefied Petroleum Gas (LPG) to paraffin wax. GTL makes it possible to obtain clean diesel, naphtha, lubes, olefins, and other industrially important organics from natural gas. This article is a brief review discussing the state-of-the-art of GTL, including the basics of syngas manufacturing as a source for Fischer-Tropsch synthesis (FTS), hydrocarbons synthesis (Fischer-Tropsch process), and product upgrading. Each one is analyzed, and the main characteristics of traditional and catalysts technologies are presented. For syngas generation, steam methane reforming, partial oxidation, two-step reforming, and autothermal reforming of methane are discussed. For Fischer–Tropsch, we highlight the role of catalysis and selectivity to high molecular weight hydrocarbons. Also, new reactors technologies, such as microreactors, are presented. The GTL technology still faces several challenges; the biggest is obtaining the right H₂:CO ratio when using a low steam-to-carbon ratio. Despite the great understanding of the carbon formation mechanism, little has been made in developing newer catalysts. Since 60–70% of a GTL plant cost is for syngas production, it needs more attention, particularly for developing the catalytic partial oxidation process (CPO), given that modern CPO processes using a ceramic membrane reactor reduce the plant’s capital cost. Improving the membrane’s mechanical, thermal, and chemical stability can commercialize the process. Catalytic challenges accompanying the FTS need attention to enhance the selectivity to produce high-octane gasoline, lower the production cost, develop new reactor systems, and enhance the selectivity to produce high molecular weight hydrocarbons. Catalytically, more attention should be given to the generation of a convenient catalyst layer and the coating process for a given configuration. Full article

Taking the importance of Pakistan’s dire need for energy breakthrough, in this paper, we explore how the country’s vast estimated reserves of 175 billion tons of Thar coal is a useful source for the clean and efficient production of good quality liquid fuel. Coal to liquid (CTL) technology has gathered increasing attention among many countries with a sufficient volume of coal reserves, and this technology can also be implemented in Pakistan, which in result can also reduce harmful greenhouse gas (GHG) emissions in the environment. In this study, the Fischer Tropsch Synthesis (FT) liquefaction method was used, and the reactor design, chemical reactions, syngas ratio fraction, and Anderson-Schulz-Flory and Langmuir model were all obtained from the Aspen Plus simulation. The results showed that, at the optimum syngas flow rate of 9 Kg/s, the FT model produced diesel fuel at 0.00134 Kg/s. Per this calculation, the massive amount of Thar coal reserves can be transformed into 123.22 million barrels of diesel. The design of the reactor is very critical, and, in this study, it was prioritized to design a reactor that produces liquid fuel only of composition C₁₂+; during the production of liquid fuel, the quantity of methane is not high; and it can still be further reduced on optimized conditions. On the other hand, CO₂ gas, which is a sole contributor of GHG emissions, was also reduced by up to 98%. Full article

Syngas has been utilized in the production of chemicals and fuels, as well as in the creation of electricity. Feedstock impurities, such as nitrogen, sulfur, chlorine, and ash, in syngas have a negative impact on downstream processes. Fischer–Tropsch synthesis is a process that relies heavily on temperature to increase the production of liquid fuels (FTS). In this study, waste biomass converted into activated carbon and then a carbon-supported iron-based catalyst was prepared. The catalyst at 200 °C and 350 °C was used to investigate the influence of temperature on the subsequent application of syngas to liquid fuels. Potassium (K) was used as a structural promoter in the Fe-C catalyst to boost catalyst activity and structural stability (Fe-C-K). Low temperatures (200 °C) cause 60% and 80% of diesel generation, respectively, without and with potassium promoter. At high temperatures (350 °C), the amount of gasoline produced is 36% without potassium promoter, and 72% with promoter. Iron carbon-supported catalysts with potassium promoter increase gasoline conversion from 36.4% (Fe-C) to 72.5% (Fe-C-K), and diesel conversion from 60.8% (Fe-C) to 80.0% (Fe-C-K). As seen by SEM pictures, iron particles with potassium promoter were found to be equally distributed on the surface of activated carbon. Full article

Fischer–Tropsch synthetic (FT) fuels are expected to be an ideal alternative for diesel fuel to achieve higher thermal efficiency and reduction in exhaust emissions because of their characteristics of being aromatic-free, sulfur-free, and high cetane number. In this study, the effects of chemical compositions and cetane number of FT fuels on diesel engine performance were investigated by using a commercial GTL (Gas-to-Liquids) diesel fuel synthesized by the FT method and blended paraffinic hydrocarbon fuels made to simulate FT fuels with different chemical compositions and cetane numbers. At first, a commercial diesel fuel (JIS No.2) and GTL were examined by varying the intake oxygen concentrations with cooled EGR. Compared with diesel fuel, GTL shows shorter premixed combustion, smaller heat release peak, and longer diffusion combustion duration at both high and medium conditions due to the higher cetane number. Further, by using the GTL, a limited improvement in thermal efficiency and exhaust emission reduction of NOx have been obtained, but no significant reduction in the smoke emissions is achieved, even though FT fuels have been considered smokeless due to their aromatic-free characteristics. Next, three types of paraffinic hydrocarbon fuels with cetane numbers of 78, 57, and 38 were blended as simulated FT fuels and were examined under the same experimental apparatus and operation conditions. For the low cetane number simulated FT fuel (cetane number 38 fuel), the results show that the ignition delay and premixing period are significantly longer at low intake oxygen concentration conditions, meaning that the premixing of low cetane number fuel is more sufficient than other fuels, especially under the high EGR rate conditions, resulting in fewer smoke emissions. Furthermore, with CN38 fuel, an excellent indicated thermal efficiency was obtained at the high load condition. To summarize the results, the low cetane number FT fuel shows a potential to achieve higher thermal efficiency and reduction in exhaust emissions on commercial diesel engines with EGR. Full article

As a part of the worldwide efforts to substantially reduce CO₂ emissions, power-to-fuel technologies offer a promising path to make the transport sector CO₂-free, complementing the electrification of vehicles. This study focused on the coupling of Fischer–Tropsch synthesis for the production of synthetic diesel and kerosene with a high-temperature electrolysis unit. For this purpose, a process model was set up consisting of several modules including a high-temperature co-electrolyzer and a steam electrolyzer, both of which were based on solid oxide electrolysis cell technology, Fischer–Tropsch synthesis, a hydrocracker, and a carrier steam distillation. The integration of the fuel synthesis reduced the electrical energy demand of the co-electrolysis process by more than 20%. The results from the process simulations indicated a power-to-fuel efficiency that varied between 46% and 67%, with a decisive share of the energy consumption of the co-electrolysis process within the energy balance. Moreover, the utilization of excess heat can substantially to completely cover the energy demand for CO₂ separation. The economic analysis suggests production costs of 1.85 €/l_DE for the base case and the potential to cut the costs to 0.94 €/l_DE in the best case scenario. These results underline the huge potential of the developed power-to-fuel technology. Full article

To solve the challenge of decarbonizing the transport sector, a broad variety of alternative fuels based on different concepts, including Power-to-Gas and Power-to-Liquid, and propulsion systems, have been developed. The current research landscape is investigating either a selection of fuel options or a selection of criteria, a comprehensive overview is missing so far. This study aims to close this gap by providing a holistic analysis of existing fuel and drivetrain options, spanning production to utilization. For this purpose, a case study for Germany is performed considering different vehicle classes in road, rail, inland waterway, and air transport. The evaluated criteria on the production side include technical maturity, costs, as well as environmental impacts, whereas, on the utilization side, possible blending with existing fossil fuels and the satisfaction of the required mission ranges are evaluated. Overall, the fuels and propulsion systems, Methanol-to-Gasoline, Fischer–Tropsch diesel and kerosene, hydrogen, battery-electric propulsion, HVO, DME, and natural gas are identified as promising future options. All of these promising fuels could reach near-zero greenhouse gas emissions bounded to some mandatory preconditions. However, the current research landscape is characterized by high insecurity with regard to fuel costs, depending on the predicted range and length of value chains. Full article