Fischer Tropsch Syncrude Research Articles

Entrained flow gasification-based biomass-to-X processes: A techno-economic assessment

In the pursuit of a successful energy transition, synthetic basic chemicals and fuels, alongside renewable energies, play pivotal roles. This study focuses on the utilization of biomass as a carbon source to replace conventional fossil feedstocks, conducting detailed process simulations and techno-economic analyses for various biomass-to-x pathways. Six key products—Methanol, Dimethyl Ether, Methane (SNG), Fischer-Tropsch syncrude, Hydrogen, and Ammonia—derived from entrained flow gasification of a representative biomass are systematically compared. The uniformity of simulation detail and economic methodology enables a direct and comprehensive comparison of these products. Notably, carbon-based products exhibit up to 34% lower average investment costs compared to their hydrogen-based counterparts, namely ammonia and hydrogen. This cost discrepancy is reflected in the levelized costs of manufacturing, with hydrogen-based products emerging as the most energy-expensive. The analysis identifies variable costs as the primary contributor to overall costs with around 50%, followed by fixed investment. The study underscores the critical impact of full load hours, plant lifetime, and feedstock costs on results. This emphasise the importance of detailed planning if alternative feedstock is used to balance fuel costs and enhance plant availability. Among the evaluated products, methanol emerges as the most promising across the evaluated KPIs with costs of 283.48 € MWh−1. However, regarding hydrogen-based products, it is suggested that, especially in the context of CO2 abatement costs, a comprehensive consideration of the long-term system effects is essential to prevent misinvestments during the early stages of the energy transition. This emphasizes the need for strategic planning to ensure a sustainable and economically viable shift towards biomass-derived synthetic fuels.

Turning CO2 from fuel combustion into e-Fuel? Consider alternative pathways

Carbon capture and utilisation technologies for the separation and conversion of CO2 into chemical products via electrochemical processes (i.e., so called electro-fuels/e-Fuels, or electro-chemicals/e-Chemicals) are envisaged to be an option in the forthcoming decarbonisation of energy and industry, but their effectiveness in terms of carbon emissions avoidance is debated. This work challenges the exploitation of CO2 from fuel combustion for the synthesis of e-Fuels, as opposed to alternative pathways. The investigated conversion routes refer to a case study for the abatement of CO2 emissions from a refinery fuel gas via production of synthetic fuels based on: (i) hydrogenation of CO2 with green H2 (i.e., e-Fuel); or (ii) electrified heating and electrified reforming of the fuel gas. For both options, two products are compared: methanol and Fischer–Tropsch syncrude. The study shows that avoiding CO2 emissions by turning CO2 from fuel combustion into an e-Fuel results in higher electricity demand, higher capital costs, and higher fuel costs than the electrification of heat supply and the direct conversion of the original fuel into a higher value synthetic fuel via electrified reforming.

Entrained flow gasification-based biomass-to-X processes: An energetic and technical evaluation

A large number of process routes is available for the production of sustainable energy carriers from biogenic residues. Benchmarking these routes usually suffers from a lack of comparable performance data. The present work addresses this through a comprehensive model-based comparison of various biomass-to-X routes. Herein, seven routes (methanol, synthetic natural gas, dimethyl ether, Fischer-Tropsch syncrude, ammonia, and hydrogen with and without carbon capture) are modelled in detailed Aspen Plus® simulations. The evaluation itself is based on various key performance indicators, which capture both energetic (i.e. energy yield and usable heat per feedstock) and material-based (i.e. carbon and hydrogen conversion efficiency, and CO2 emissions) properties of the routes. The results show, that no simple correlations can be drawn between energetic and material-based indicators. In summary across all considered properties, the methanol route exhibits the best combined results, in particular with the highest carbon efficiency of 40 %. Fischer-Tropsch is more suitable for integration into existing industrial parks due to the lowest energy yield of 40 % with a lot of by-product formation and the highest amount of useable heat per feedstock of 211.3kWMW-1. Whereas dimethyl ether and synthetic natural gas have potential for integration into heat grids, mainly due to their good conversion and simultaneous large heat dissipation. Ammonia and hydrogen should only be considered in combination with carbon capture. Therefore, the key performance indicators determined herein must be considered together with project- and location-specific requirements and the market outlook for the product.

Techno-economic feasibility of a biomass-to-X plant: Fischer-Tropsch wax synthesis from digestate gasification

A techno-economic analysis is performed, assessing the production costs of Fischer-Tropsch syncrude and waxes of carbon number C20+. The products are obtained from the gasification of digestate from anaerobic digestion inside a dual fluidized bed gasifier (3.11 MWth). The results are compared against the same system fed with lignocellulosic biomass. The syngas is cleaned from impurities and conditioned to reach the desired H2/CO molar ratio of 1.8 at the inlet of the Fischer-Tropsch reactor. The Fischer-Tropsch products distribution is based on experimental data of a cobalt-based catalyst. Two process configurations are studied: (1) the Fischer-Tropsch off-gas are employed to produce electricity; (2) the off-gas are recirculated to the gasifier for enhanced wax production. Co-production of steam is also investigated. The results show an advantageous production of Fischer-Tropsch compounds utilizing digestate over wood biomass. The highest plant efficiency (i.e., biomass-to-liquid fuel) of 56.3% is reached with digestate feedstock and off-gas recirculation, outputting 61.5 kgwax/tdig. The minimum wax production cost is of 3.04 €/kgwax, assuming 7.5% discount rate and 25-years plant operation.

Techno-economic and life-cycle assessment of integrated Fischer-Tropsch process in ethanol industry for bio-diesel and bio-gasoline production

The Fischer-Tropsch process is less complex and more environmentally friendly alternative to petroleum-based fuels. With growing interest in biomass-to-fuel conversion like the production of bioethanol, there is a steady supply of unfermentable biomass from bioethanol industries, which can be gasified and converted to Fischer-Tropsch syncrude. In this work, the economic and ecological feasibility of integrating a Fischer-Tropsch process using syngas obtained from the gasification of dry distillers’ grain is explored. Data from a lab-scale experiment using pelletized promoted iron supported on Carbon Nano Tubes (Fe/CNT) is used to simulate a plant for the production of 1000 kg of syncrude/h. The techno-economic feasibility of setting up a Fischer-Tropsch process is explored based on chemical engineering plant cost index of 628.2. An internal rate of return of 107.9% was obtained with a net annual profit of 5.2 MUSD/year which is higher than those reported for other Fischer-Tropsch plants due to the readily availability of the feedstock without any associated transportation costs. The potential environmental impact of the Fischer-Tropsch fuels was evaluated by the WAste Reduction (WAR) algorithm and suggested that the integration of the Fischer-Tropsch process into the bio-ethanol production plant is environmentally benign.

The impact of biomass drying on the efficiency of a gasification plant co-producing Fischer-Tropsch fuels and heat – A conceptual investigation

This study examines the impact of biomass drying on the overall efficiency of a Biomass-to-Liquids (BTL) process co-producing Fischer-Tropsch (FT) syncrude and heat. The proposed BTL process is based on steam-blown dual fluidised-bed gasification of biomass, simplified gas clean-up and FT synthesis. Biomass drying was found to have a significant effect on both the FT product yield and the overall thermal efficiency of the BTL plant. In the considered concept, FT off-gases are used as supplementary feedstock in the oxidiser, alongside with char, to satisfy the heat demand in gasification. Drying of the biomass feedstock leads to reduced need of water evaporation during gasification. This in turn reduces the demand for off-gases in the oxidiser, and allows to produce more syncrude (and less off-gases) in the FT unit. The simulations indicated that more extensive drying could result in a significant increase in FT syncrude yield: the thermal efficiency of FT syncryde production increased from 47.7% to 54.6% as the moisture mass fraction of the biomass feed was reduced from 30% to 8%. The highest overall thermal efficiencies of 85–88% were obtained with a two-stage drying concept that combines a belt dryer and an indirectly-heated steam dryer.

Modeling Vapor–Liquid–Liquid Phase Equilibria in Fischer–Tropsch Syncrude

Vapor–liquid–liquid equilibrium (VLLE) during product recovery and separation after Fischer–Tropsch synthesis affects the efficiency of downstream processing. Proper prediction of the VLLE is necessary to improve this processing step in the Fischer–Tropsch process; however, there is little guidance on what thermodynamic models to use. A similar problem presents itself in processes related to biomass conversion. The selection of an appropriate thermodynamic model to describe the nonideal VLLE of water–oxygenate–hydrocarbon mixtures was investigated. Cubic equations of state, virial equations of state, activity coefficient models, and equations of state with advanced mixing rules were considered. The evaluation was conducted using both default and optimized parameters. Predictive performance was improved when binary interaction parameters were optimized using experimental data, but parameter optimization is onerous and it is not always practical. It was found that cubic equations of state should not be used...

A novel hybrid feedstock to liquids and electricity process: Process modeling and exergoeconomic life cycle optimization

This article proposes a novel hybrid low‐rank coal (LRC)/biomass/natural gas process for producing liquid fuels and electricity. The hybrid process highlights coexistence of indirect and direct liquefaction technologies, cogasification of char and biomass, and corefinery of LRC syncrude and Fischer–Tropsch syncrude. A process simulation based on detailed chemical kinetics is present to illustrate its feasibility. In addition, we propose an exergoeconomic life cycle optimization framework that seeks to maximize the primary exergy saving ratio, primary total overnight cost saving ratio, life cycle waste emissions avoidance ratio, and primary levelized cost saving ratio by comparing the proposed hybrid process to its reference stand‐alone subsystems. From the results, we can determine four optimal designs which yield competitive breakeven oil prices ranging from $1.87/GGE to $2.13/GGE. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3739–3753, 2014

Integration of Fischer-Tropsch fuel production with a complex oil refinery

The oil refining industry is facing harder policies on renewable content in its products. One way to meet this is to produce diesel and gasoline from gasification of biomass via a Fischer-Tropsch (FT) synthesis. In this paper, heat integrating a biomass-to-FT syncrude process with a refinery is compared to a stand-alone biomass-to-FT syncrude process, in terms of the consequences for GHG emissions and energy balances. The upgrading of the FT syncrude is in both cases accomplished at the refinery, in the existing units or in new units. The studied system includes a circulating fluidised-bed biomass gasifier with a biomass input of 500 MW (50% moisture content) and a complex refinery with a crude oil capacity of 11.4 Mt/y. The integrated FT syncrude production shows the greatest potential for reductions in GHG emissions. Still, the GHG emission mitigation potential of using biomass for FT fuel production is smaller than co-firing biomass with coal in coal power plants.

“Catalysis in the Refining of Fischer–Tropsch Syncrude”

“Catalysis in the Refining of Fischer–Tropsch Syncrude”

High-Octane Gasoline Production by Upgrading Low-Temperature Fischer–Tropsch Syncrude

Technology selection for refining the lighter fractions of syncrude produced by low-temperature Fischer–Tropsch (LTFT) synthesis into high octane motor-gasoline with no decrease in distillate production has been investigated. It was found that an upgrading scheme based on Pt/L-zeolite reforming, non-hydrogen aromatization and olefin oligomerization can produce high quality motor gasoline which can meet current gasoline specifications (Euro-4). A second scheme, which we call “full aromatization”, is also evaluated on the basis of liquid yield and octane number. The full aromatization process appears to be the least complex refining scheme that provides a sufficiently high octane number, but the gasoline produced from this process may require additives to meet current motor gasoline specifications.

Fischer–Tropsch fuels refinery design

Carbon sources, such as coal, natural gas, biomass and waste, can be converted into transportation fuels by combining appropriate gasification, Fischer–Tropsch and refining technologies. Efficient refining of the Fischer–Tropsch synthesis derived syncrude requires a different approach to refinery design than commonly applied to crude oil refinery design. The design of refineries to optimise the production of on-specification motor-gasoline, jet fuel and diesel fuel respectively from both high temperature Fischer–Tropsch (HTFT) syncrude and low temperature Fischer–Tropsch (LTFT) are considered. Refinery designs are presented for the production of motor-gasoline and jet fuel with better than 50% yield (better than 70% selectivity on transportation fuel), without resorting to very complex designs. Only diesel fuel refining presented a problem, since the production of on-specification EN590:2004 diesel fuel is limited by a Fischer–Tropsch specific cetane-density-yield trade-off. The compound classes that are required to produce diesel fuel in high yield that meet both minimum cetane number and minimum density requirements are not abundant in Fischer–Tropsch syncrude. Refinery designs for diesel fuel production was limited to a yield of less than 25% EN 590 : 2004 compliant diesel fuel. This yield restriction does not apply when diesel fuel specifications do not have a minimum density requirement.

Fischer–Tropsch refining: technology selection to match molecules

On a molecular level Fischer–Tropsch syncrude is significantly different from crude oil. When syncrude is treated as if it is a crude oil, its refining becomes inefficient. Refining technologies developed for crude oil can be employed to refine Fischer–Tropsch syncrude, but in order to conform to green chemistry principles (preventing waste; maximising atom economy; increasing energy efficiency) the technology selection must be compatible with the syncrude composition. The composition of Fischer–Tropsch syncrude is discussed in relation to the molecular requirements of transportation fuels and the refining gap that needs to be bridged. Conversion technologies are evaluated in terms of their refining objective, chemistry, catalysts, environmental issues, feed requirements, and compatibility to Fischer–Tropsch syncrude, in order to suggest appropriate technologies for efficient refining of Fischer–Tropsch products. The conversion technologies considered are: double bond isomerisation, dimerisation/oligomerisation, skeletal isomerisation, etherification, aliphatic alkylation, aromatic alkylation, metathesis, hydrogenation/hydrotreating, hydroisomerisation, hydrocracking, catalytic cracking, coking, thermal cracking, catalytic reforming, aromatisation, alcohol dehydration and olefin hydration.

Hydroprocessing peculiarities of Fischer–Tropsch syncrude

When catalysts developed for crude oil hydroprocessing are used for syncrude, there are syncrude-specific peculiarities to consider. These relate to differences in the nature and abundance of heteroatoms, olefins, metal species, waxes and aqueous products. Some important aspects are (a) heat release during naphtha and distillate hydroprocessing is very high, but wax hydrocracking is almost isothermal; (b) syncrude is sulphur-free and the use of sulphided base-metal hydroprocessing catalysts require the addition of sulphur-containing compounds to the syncrude; (c) oxygenates strongly adsorb on some catalytic surfaces to affect catalytic behaviour; (d) carbonyl–carboxylic acid interconversion and water produced by hydrodeoxygenation (HDO) may result in catalyst degradation by acid and hydrothermal attack; (e) carboxylic acids in syncrude result in equipment corrosion and catalyst leaching; (f) metal carboxylates are the main metal-containing species in syncrude and are not removed by hydrodemetallation (HDM) catalysis, but by thermal decomposition.

Environmentally friendly refining: Fischer–Tropsch versus crude oil

Projected changes in crude oil refinery design to meet future fuel specifications require that intermediates are produced that are already present in Fischer–Tropsch syncrude. A qualitative comparison is made between syncrude and crude oil, and the refinery designs needed to convert these raw materials into transportation fuels. Syncrude is sulfur free, nitrogen free and contains no heteroatom rich residues, making its purification and separation less complex than that of crude oil. The conversion units needed to produce motor-gasoline, jet fuel and diesel from syncrude are of similar complexity to that of crude oil, but crude oil residue conversion is much more involved. Furthermore, cleaner conversion technologies can be used to upgrade syncrude. A Fischer–Tropsch refinery consequently has a smaller environmental footprint than a crude oil refinery.