Minimum Fuel Selling Price Research Articles

One techno-economic analysis to rule them all: Instant prediction of hydrothermal liquefaction economic performance with a machine learned analytic equation

Hydrothermal liquefaction (HTL) has remarkable potential for efficient conversion of abundant, decentralized organic wastes into renewable fuels. Because waste is a highly distributed resource with context-dependent economic viability, selection of optimal deployment sites is slowed by the need to develop detailed techno-economic analyses (TEA) for the thousands of potential deployment locations, each with their own unique combinates of scale, proximity to infrastructure/markets, and feedstock properties. An economic modeling framework that requires only easily obtainable inputs for assessing economic performance would therefore allow multiplexed analysis of many thousands of cases, whereas traditional TEA would not be possible for more than a handful of cases. Within such a context, the present study uses machine learning to guide development of a TEA and modeling framework which provides accurate cost predictions using three key inputs – feedstock cost, biocrude yield, and process scale – to estimate the minimum fuel selling price (MFSP) that an HTL process can achieve. The structure of the proposed framework is informed and based on empirical observations of cost projections made by a detailed TEA over a wide range of feedstock costs, biocrude yields, and process scales. A machine learning guided process was used to identify, train, and test a series of models using auto-generated data for training and independently reported data for testing. The most accurate model consists of three terms and requires 6 adjustable parameters to predict independently published values of MFSP (N = 28) to within an average value of ± 20.4%. It is demonstrated that the reduced-order model’s predictions fall within 40% of the corresponding published values 95% of the time, and in the worst case, the associated discrepancy is 45.9%, suggesting that the accuracy of the machine learned model is indeed comparable to the TEAs that were used to build it. Moreover, the terms in the model are physically interpretable, conferring greater reliability to the use of its predictions. The model can be used to predict the dependence of MSFP on biocrude yield, scale, and feedstock cost; interestingly, MFSP is insensitive to biocrude yield and/or scale under many situations of interest and identifying the critical value for a given application is crucial to optimizing economic performance. The proposed model can be also extended to evaluate economic performance of newly developed HTL-based processes, including catalytic HTL, and the methodological framework used in this study is deemed appropriate for the development of machine learned TEA models in cases of other similar waste-to-energy technologies.

Techno-economic analysis of bioplastic and biofuel production from a high-ash microalgae biofilm cultivated in effluent from a municipal anaerobic digester

Rotating Algae Biofilm Reactors (RABRs) are a promising technology for efficient treatment of wastewater and production of algae-based bioproducts. However, RABR-grown algae can contain a high content of ash (30–60 wt%, dry basis), which influences the technical and economic feasibility of bioproduct conversion processes. In this report, experimental studies and economic analysis were conducted to compare different processes for bioproduct conversion of a high-ash microalgae biofilm grown using a RABR treating 0.6 million gallons per day of anaerobic digestion centrate at the Central Valley Water Reclamation Facility in Salt Lake City, UT. Process and economic models were developed and compared for three conversion processes: 1) the production of bioplastics, 2) the production of bioplastics with a lipid-extraction pretreatment, and 3) the production of biocrude via hydrothermal liquefaction. Techno-economic analysis was performed for each conversion process, including three cases for algae productivity: 231, 391, and 577 metric tons per year (dry basis). The calculated value for the minimum plastic selling price (MPSP) of bioplastics produced from algae ranges from $4050 to $3520 per metric ton based on the baseline and final productivity cases of the RABR, respectively. The extraction of lipids in addition to bioplastic production results in an MPSP of $4570 to $4000 per metric ton for the same productivity cases. The relatively small production scale and complex processing for hydrothermal liquefaction results in a minimum fuel selling price of the biocrude of $5.32 per gallon of gasoline equivalent. The conversion process for bioplastic production from whole algae has the highest income:expense ratio and the most cost-competitive pricing of the three modeled processes.

Intensified biogas to liquid (IBGTL) Process: Experimental validation and modeling analysis

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.

Techno-economic assessment of gasoline production from Fe-assisted lignocellulosic biomass hydrothermal liquefaction process with minimized waste stream

Techno-economic analyses were conducted on an iron-assisted hydrothermal liquefaction (HTL) process for converting lignocellulosic biomass into gasoline, comparing two approaches for minimizing by-product streams. The primary difference between the two approaches lies in their hydrogen (H₂) source for upgrading bio-crude to bio-gasoline. Scheme 1 utilizes residual water-soluble and gaseous compounds from the process to generate the H₂ needed for upgrading. Scheme 2, on the other hand, converts these waste streams into heat to supply part of the required energy, while external H₂ from steam methane reforming (with or without CO₂ capture) or water electrolysis (green hydrogen) is used for upgrading. Both schemes use pinewood and red mud as feedstocks. Red mud, after the reduction of Fe₂O3 to metallic iron, is employed in the HTL reactor as a hydrogen producer, enhancing both the yield and quality of the bio-crude while minimizing the H2 consumption in the upgrading unit. The HTL reactor was modeled based on optimal operating conditions experimentally determined while sensitivity analyses were performed on the other scheme’s units to determine their optimal conditions. A Life Cycle Assessment (LCA) was also conducted to measure the environmental impact of the two scenarios.Both schemes produce 459 tonnes of gasoline equivalent per day, consuming 33 tonnes of H2. Scheme 2 achieves a minimum fuel selling price (MFSP) of $0.94 per liter of gasoline equivalent (LGE), with methane reforming and CO₂ capture providing the lowest emissions (1.13 kg CO₂-Eq per kg of LGE). Scheme 1 has a slightly higher MFSP of $0.96 per LGE but is more environmentally sustainable, with a LCA showing 1.11 kg CO₂-Eq per kg of LGE.

Economic and sustainability prospects for wet waste valorization: The case for sustainable aviation fuel from arrested anaerobic digestion

Valorizing wet wastes to sustainable aviation fuel (SAF) can be achieved through sequential arrested anaerobic digestion (AAD) to volatile fatty acids (VFAs) and thermochemical catalytic upgrading. Alternatively, conventional anaerobic digestion (AD) can use wet waste to produce biogas (for electricity generation), biomethane, or green hydrogen. To assess the VFA-SAF pathway, we conducted a comprehensive techno-economic analysis (TEA) of each approach using Aspen Plus and discounted cash flow models, coupled with life cycle assessment (LCA) to estimate fuel carbon intensity (CI) and evaluate the implications of policy incentives for carbon emissions reduction.First, we calculated the minimum fuel selling price (MFSP) required to meet a 10 % internal rate of return (IRR) for each product without policy incentives. In this scenario, all pathways faced challenges in meeting the market values of equivalent fossil-based products. Next, we examined projected costs for alternative sustainable technologies and found that SAF and biomethane from wet waste were competitive, while electricity and hydrogen costs were significantly higher. Finally, we incorporated current policy incentives; with incentives, all pathways exceeded a 10 % IRR using fossil-equivalent selling prices. Among all the options considered, VFA-SAF produced the most profitable carbon-negative fuel that was economically competitive with alternative sustainable technologies.

Effect of thermodynamic models on process modelling and techno-economics for biofuel. A case study using fractional distillation of an algae biocrude

This modelling study highlighted the impact of thermodynamic methods on process modelling results and subsequent technical and economic aspects of biofuel production. Fractional distillation of biocrude derived from thermal liquefaction of algae was modelled using three widely used thermodynamic property methods, namely Peng-Robinson, NRTL and PSRK. Process models revealed differences in mass and energy flows when using different thermodynamic models. Most importantly, for different thermodynamic models, significant variations in the separation of key components were found, affecting the proportion of biofuel fractions. One fraction varied in the amount of key components in the range of 100%–600%. These variations subsequently affected financial parameters. The net present value exhibited a difference of between US$7.8 and US$5.8 million when comparing the Peng-Robinson model to the PSRK model in different scenarios, and US$3.4–4.5 million when comparing PSRK and NRTL. The profitability of biofuel production was most dependent on biocrude yield and algae price. A switch-value analysis resulted in an algae feedstock price of $286.20/t, below which biofuel production becomes profitable. By considering two distinct scenarios characterized by different feedstock prices, the minimum fuel selling price was estimated to be competitive with fossil fuels: US$1.1/L when algae was US$474/t and US$0.5/L when algae was cheaper (US$65/t).

Algae to HEFA: Economics and potential deployment in the United States

AbstractTo reach the goals set by the US Department of Energy's Sustainable Aviation Fuel (SAF) Grand Challenge, currently available feedstocks may be insufficient. Giving priority to developing, prototyping and reducing the cost of algal feedstock before investing and lining up locations is important. As the production of algal feedstocks advances, a simplified conversion approach using more mature technologies can help reduce the investment risk for algae‐based fuels. Reducing process complexity to the steps described here [namely, conversion of lipids to HEFA (hydroprocessed esters and fatty acids) fuels and relegating the remainder of the biomass to anaerobic digestion or food/feed production] enables the near‐term production of algal SAF but presents challenging economics depending on achievable cultivation costs and compositional quality. However, these economics can be improved by present‐day policy incentives. With these incentives, the modeled algae‐to‐HEFA pathway could reach a minimum fuel selling price as low as $4.7 per gasoline gallon equivalent depending on the carbon intensity reduction that can be achieved compared with petroleum. Uncertainty about algal feedstock production maturity in the current state of technology and the future will play a large role in determining the economic feasibility of building algae‐to‐HEFA facilities. For example, if immaturity increases the feedstock price by even 10%, SAF production in 2050 is about 58% of the production which could have been achieved with mature feedstock. Additionally, growth in this conversion pathway can be notably boosted through the inclusion of subsidies, and also through higher‐value coproducts or higher lipid yields beyond the scope of the process considered here.

Techno-Economic Assessment of Electromicrobial Production of n-Butanol from Air-Captured CO2.

Electromicrobial production (EMP), where electrochemically generated substrates (e.g., H2) are used as energy sources for microbial processes, has garnered significant interest as a method of producing fuels and other value-added chemicals from CO2. Combining these processes with direct air capture (DAC) has the potential to enable a truly circular carbon economy. Here, we analyze the economics of a hypothetical system that combines adsorbent-based DAC with EMP to produce n-butanol, a potential replacement for fossil fuels. First-principles-based modeling is used to predict the performance of the DAC and bioprocess components. A process model is then developed to map material and energy flows, and a techno-economic assessment is performed to determine the minimum fuel selling price. Beyond assessing a specific set of conditions, this analytical framework provides a tool to reveal potential pathways toward the economic viability of this process. We show that an EMP system utilizing an engineered knallgas bacterium can achieve butanol production costs of <$6/gal ($1.58/L) if a set of optimistic assumptions can be realized.

Comparative assessment of pyrolysis and Gasification-Fischer Tropsch for sustainable aviation fuel production from waste tires

The aviation industry is a major source of greenhouse gas emissions, making it critical to transition from traditional fossil jet fuels to eco-friendly sustainable aviation fuels (SAF). This change is essential to achieve the goal of net-zero emissions by 2030. Moreover, Waste tires presents a significant environmental challenge due to their durability and difficulty of disposal. Their toxic and flammable nature complicates storage and processing. To address these challenges, waste tires can be processed to SAF using thermochemical processes such as pyrolysis to bio-oil and hydroprocessing, or gasification to syngas and Fischer-Tropsch synthesis (GFT). While waste tires appear to be a viable feedstock,there have not been studies to date that thoroughly compared the most efficient thermochemical process of converting waste tires to SAF. This study compares the economic and environmental impacts of two waste tire based SAF production methods (Pyrolysis/hydroprocessing and GFT). Economically, both methods are more favorable compared to other SAF pathways such as alcohol to jet (ATJ) or hydroprocessing of esters and fatty acids (HEFA). Pyrolysis SAF costs more (0.78 USD/l) than GFT SAF (0.66 USD/l). Pyrolysis is sensitive to hydrogen costs, with a 30% price fluctuation significantly impacting its minimum fuel selling price (MFSP). In contrast, the GFT method is more influenced by catalyst costs. Environmentally, pyrolysis emits less CO2 (34.3 kg CO2 eq/kg SAF) compared to GFT (58.6 kg CO2 eq/kg SAF) but has a higher potential environmental impact in several categories, except for terrestrial ecotoxicity, where both methods are similar. Although pyrolysis has a lower global warming potential (GWP), it presents higher risks in toxicity and photochemical pollution.

Techno-economic analysis and environmental impact assessment of biodiesel production from bio-oil derived from microwave-assisted pyrolysis of pine sawdust

Pyrolysis stands out as a highly promising technology for converting biomass. Upgrading the bio-oil to meet the requirements for fuelling internal combustion engines is indispensable. This study evaluates the economic viability of microwave-assisted pyrolysis (MAP) of pine sawdust, followed by bio-oil esterification for the production of biodiesel. Aspen Plus® was used to simulate a facility that processed 2000 metric tonnes of pine sawdust per day. The minimum fuel selling price (MFSP) of biodiesel was established through the use of a discounted cash flow analysis. A life cycle assessment approach was used to evaluate the environmental impact assessment of biodiesel production. Process modelling findings revealed that the pyrolysis section yielded 65.8 wt% bio-oil, 8.9 wt% biochar, and 25.3 wt% NCGs. The biodiesel product yield was 48 wt% of the raw bio-oil, yielding 631.7 tonnes per day of biodiesel. With the cost of methanol playing a significant role, the overall capital investment was $286.1 MM and the total yearly operating expenses were $164.9 MM. The predicted MFSP for biodiesel is $2.31/L, with yearly operational expenses and biodiesel output being the most important factors. The emission from the biodiesel production process resulted in a global warming potential of 70.97 kg CO2eq. With an anticipated MFSP that is competitive with traditional diesel fuel, the study concludes that the method is economically viable. The results underline how crucial it is to optimize crucial process variables in order to increase the process's economic viability.

Technical, economic and environmental analysis of solar thermochemical production of drop-in fuels

This study analyzes the technical performance, costs and life-cycle greenhouse gas (GHG) emissions of the production of various fuels using air-captured water and CO2, and concentrated solar energy as the source of high-temperature process heat. The solar thermochemical fuel production pathway utilizes a ceria-based redox cycle for splitting water and CO2 to syngas – a tailored mixture of H2 and CO – which in turn is further converted to liquid hydrocarbon fuels. The cycle is driven by concentrated solar heat and supplemented by a high-temperature thermal energy storage for round-the-clock continuous operation. The study examines three locations with high direct normal irradiation using a baseline heliostat field reflective area of 1 km2 for the production of six fuels, i.e. jet fuel and diesel via Fischer-Tropsch, methanol, gasoline via methanol, dimethyl ether, and hydrogen. Two scenarios are considered: near-term future by the year 2030 and long-term future beyond 2030.In the near-term future in Sierra Gorda (Chile), the minimum fuel selling price is estimated at around 76 €/GJ (2.5 €/L) for jet fuel and diesel, 65 €/GJ for methanol, gasoline (via methanol) and dimethyl ether (DME), and 42 €/GJ for hydrogen (excluding liquefaction). In the long-term future, with advancements in solar receiver, redox reactor, high-temperature heat recovery and direct air capture technologies, the industrial-scale plant could achieve a solar-to-fuel efficiency up to 13–19 %, depending on the target fuel, resulting in a minimum fuel selling price of 16–38 €/GJ (0.6–1.3 €/L) for jet fuel and diesel, and 14–32 €/GJ for methanol, gasoline, and DME, making these fuels synthesized from sunlight and air cost-competitive vis-à-vis e-fuels. To produce the same fuels in Tabernas (Spain) and Ouarzazate (Morocco) as in Sierra Gorda, the production cost would increase by 22–33 %. Greenhouse gas savings can be over 80 % already in the near-term future.

Sustainable aviation fuel production using in-situ hydrogen supply via aqueous phase reforming: A techno-economic and life-cycle greenhouse gas emissions assessment

Sustainable aviation fuel (SAF) production is one of the strategies to guarantee an environmental-friendly development of the aviation sector. This work evaluates the technical, economic and environmental feasibility of obtaining SAFs by hydrogenation of vegetable oils thanks to in-situ hydrogen production via aqueous phase reforming (APR) of glycerol by-product. The novel implementation of APR would avoid the environmental burden of conventional fossil-derived hydrogen production, as well as intermittency and storage issues related to the use of RES-based (renewable energy sources) electrolysers. The conceptual design of a conventional and advanced (APR-aided) biorefinery was performed, considering a standard plant capacity equal to 180 ktonne/y of palm oil. For the advanced scenario, the feed underwent hydrolysis into glycerol and fatty acids; hence, the former was subjected to APR to provide hydrogen, which was further used in the hydrotreatment reactor where the fatty acids were deoxygenated. The techno-economic results showed that APR implementation led to a slight increase of the fixed capital investment by 6.6% compared to the conventional one, while direct manufacturing costs decreased by 22%. In order to get a 10% internal rate of return, the minimum fuel selling price was found equal to 1.84 $/kg, which is 17% lower than the one derived from conventional configurations (2.20 $/kg). The life-cycle GHG emission assessment showed that the carbon footprint of the advanced scenario was equal to ca. 12 g CO2/MJSAF, i.e., 54% lower than the conventional one (considering an energy-based allocation). The sensitivity analysis pointed out that the cost of the feedstock, SAF yield and the chosen plant size are keys parameters for the marketability of this biorefinery, while the energy price has a negligible impact; moreover, the source of hydrogen has significant consequences on the environmental footprint of the plant. Finally, possible uncertainties for both scenarios were undertaken via Monte Carlo simulations.

Techno-economic analysis of a microalgae-based biorefinery network for biofuels and value-added products

Biorefineries have the potential to become economically competitive through the exploitation of all biomass conversion scenarios. This study presents a technoeconomic assessment of a microalgal biorefinery for the integrated production of biodiesel, biobutanol, and co-products acetone, ethanol, and glycerol. Pre-treatment stages include acid hydrolysis (AH) and solvent extraction (SX), in two different processing networks (Configuration 1: AH followed by SX; Configuration 2: SX followed by AH). The lowest Minimum Fuel Selling Price (MFSP) was attained by Configuration 1 ($2.11/kg total biofuel), which was 75 % and 11 % lower than the single-fuel biobutanol and biodiesel conversion scenarios, respectively. Sensitivity analysis showed that the feedstock costs, inlet rate, and solvent usage (SX), have the greatest effect on the MFSP. Results also showed that the selling price of biobutanol is highly sensitive to fluctuations in biodiesel prices, which may have implications on a growing fuels market with unpredictable supply and demand.

Techno-Economic assessment of synthetic E-Fuels derived from atmospheric CO2 and green hydrogen

E-fuels have long been thought of as one way to realise a carbon–neutral energy economy but many concerns over their economic feasibility have arisen over the years, shifting the dialogue away from their utilization, even though they provide a way to carbon-neutrally power the existing fossil fuel intensive infrastructures. In this article, we assess the potential of e-fuels as a net-zero carbon pathway and the economic implications of shifting the entire fuel demand in Saudi Arabia for powering its transportation needs to e-fuels through MTO-MOGD (Methanol-to-Olefin, Mobil’s Olefin to Gasoline and Distillate Fuels) process. This demand is currently ∼ 1 million barrel oil equivalent per day, and the study conducts a techno-economic analysis on a process simulation plant modelled to meet this demand. A minimum fuel selling price of 3.24 USD/litre for e-gasoline and 2.89 USD/litre for e-diesel were estimated, when the plant was powered by solar power. Levelized cost of e-fuel was estimated to be the lowest (∼379 USD/MWh) when the process was entirely powered by an in-situ solar photovoltaic plant and lithium ion battery banks and highest (∼564 USD/MWh) when the process was modified to produce additional methanol (while still being powered entirely by solar energy), across four different scenarios that were considered. These results show the economic implications of e-fuels aimed at decarbonizing the road transport (legacy fleet) and consequently the need for continuous and significant policy support.

Techno-economic analysis and life cycle analysis of e-fuel production using nuclear energy

Electrofuels, or e-fuels, are synthetic liquid hydrocarbon fuels which may be produced using carbon dioxide (CO2) and low carbon hydrogen (H2) as feedstock. They are of great interest because they have much lower carbon intensity compared to the conventional petroleum fuels and can utilize the existing fuel infrastructure owing to their ability to blend with or replace existing fuels. We modeled an e-fuel production process to produce low carbon jet, diesel, and naphtha using a reverse water gas shift process to produce synthesis gas, followed by a Fischer-Tropsch (FT) synthesis process. Nuclear energy is considered for e-fuel production due to its steady energy supply, near-zero carbon emissions, capability to produce hydrogen with high efficiency via high temperature electrolysis, and proximity to biogenic CO2 sources from nearby corn-ethanol plants in the United States. The modeled FT process achieved a high carbon conversion ratio of 99% by recycling CO2 and the use of oxy-combustion, and a process energy efficiency of approximately 70%. The life cycle greenhouse gases emissions are estimated to be 7 and −25 gCO2e/MJ, without and with steam coproduct credit, respectively, by using the Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET®) model. Additionally, the process economics were evaluated for three scales corresponding to nuclear power plant capacities of 100, 400, and 1000 MWe, estimating a minimum fuel selling price (MFSP) of $3.61/gal ($0.95/L), $2.82/gal ($0.74/L), and $2.66/gal ($0.70/L) of FT fuel mix, respectively, by considering $3/kg of H2 tax credit prescribed in the recent Inflation Reduction Act.

Production of Sustainable Aviation Fuels from Lignocellulosic Residues in Brazil through Hydrothermal Liquefaction: Techno-Economic and Environmental Assessments

Decarbonization of the aviation sector relies on deployment of sustainable aviation fuels (SAF) at commercial scale. Hydrothermal liquefaction (HTL) has been recognized as a promising technology to help supply the increasing projected SAF demand. High availability of agro-industrial residues, combined with a well-established biorefinery system, makes the sugarcane industry in Brazil a good option for HTL technology deployment. Moreover, challenges regarding the economic feasibility of SAF from HTL could be partially addressed by the RenovaBio policy, a market-driven incentive mechanism of carbon credits implemented in Brazil. This study investigated both the techno-economic and life cycle assessment of SAF production from sugarcane lignocellulosic residues, considering HTL integrated to a first-generation ethanol distillery and a HTL stand-alone facility. The evaluated scenarios showed great climate mitigation potential, reaching a reduction of up to 73–82% when compared to fossil jet fuel. The minimum fuel selling price of SAF at 15.4 USD/GJ indicated potential of economic competitiveness with fossil jet fuel in the best integrated scenario. The economic benefits obtained from carbon credits are not enough to enable feasibility of HTL in the stand-alone scenarios, even with carbon prices projected at 125 USD/tonne CO2-eq avoided.

Uncertainty analysis for techno-economic and life-cycle assessment of wet waste hydrothermal liquefaction with centralized upgrading to produce fuel blendstocks

Hydrothermal liquefaction is a promising technology that can produce fuels from waste with much lower greenhouse gas emissions and potential to supply 24% of total U.S. jet fuel demand. However, existing techno-economic and life-cycle assessment of hydrothermal liquefaction are subject to considerable uncertainties, which should be quantified to accelerate deployment. This work presents a comprehensive uncertainty analysis in both economic and environmental measures of the entire wet waste-to-fuel blendstock supply chain using the most recent developments in hydrothermal liquefaction and biocrude upgrading technologies. The results of a U.S. based analysis suggest an estimated biocrude yield from 42.2% to 52.4%, an estimated fuel yield from 34.7% to 42.7%, an estimated minimum fuel selling price from $2.28/gge to $3.45/gge, and an estimated supply chain greenhouse gas emissions reduction from 73.4% to 81.8% relative to petroleum-derived diesel. In addition, an open-source reduced order process model embedded with predictive reactor model is made available in the supplementary information, allowing communities interested in waste-to-energy to assess technology feasibility of hydrothermal liquefaction with their own regional data and track the technology development from economic, environment, and uncertainty perspectives. To the authors’ knowledge this model is the most comprehensive predictive model for hydrothermal liquefaction to date with regard to commercial relevancy (based on continuous testing of bench and engineering scale system), the number of data sets, and the breadth of wet wastes represented.

Strategic Assessment of Sustainable Aviation Fuel Production Technologies Using WASPAS Method

In the last 25 years, the amount of international passenger air traffic has tripled, and it is anticipated that this rapid growth will continue in the upcoming 25 years. Although it has significant economic advantages, the expansion of the aviation sector may also have more negative social and environmental effects. “Sustainable aviation policy" is created as a "balanced plan" to address this. While highlighting the financial advantages of the aviation industry, it seeks to address the significant environmental effects of its expansion. This definition of "sustainable aviation" is contested by other organizations, because there is little consensus among nongovernmental Organizations and the aviation sector. “Standard aviation policy" is therefore in dispute, and several parties attempt to change it to suit their own objectives. In order to build policies for sustainable aviation, competing environmental discourses were identified and examined through a classification exercise assisted by rhetorical, stylistic, and thematic analysis. An approach for making judgments involving multiple attributes, which ensures the consistency requirements of each reciprocal matrix, is the Analytical Hierarchy Process (AHP). Recently, a new method called the Weighted Aggregates Sum Product Assessment System (WASPAS) has been introduced in the literature. WASPAS combines the principles of the weighted product sum and basic aggregate weighting techniques. Linguistic assessments are typically chosen as in decision-making matrix when there is uncertainty and ambiguity. As a result, the purpose of this study is to synthesis WASPAS approaches and adds to the literature. The challenge of outsourcing producer evaluation and selection is resolved using the suggested approach. The options available are HEFA_SO, HEFA_YG, VB_Stover, VB_Pine, ATJ_Stover, ATJ_Pine, DSHC_Stover, DSHC_Pine, FP_Stover, FP_Pine, GFT_Stover, and GFT_Pine. The criteria used for evaluation are TCI (Total Capital Investment in MM$), OPEX (Operating Expenses in MM$), MFSP ($ L− 1) (Minimum Fuel Selling Price in dollars per liter), and MFSP ($ Mg− 1) (Minimum Fuel Selling Price in dollars per mega gram).

Economic Analysis of Thermal–Catalytic Process of Palm Oil (Elaeis guineesensis, Jacq) and Soap Phase Residue from Neutralization Process of Palm Oil (Elaeis guineensis, Jacq)

Palm oil is, from an economic, environmental, and social point of view, a vegetable oil with great potential and the state of Pará-Brazil is Brazil’s great producer. In addition, soap phase residue or palm oil neutralization sludge (PONS), a byproduct of the neutralization step of the chemical refinement of palm oil, is produced, posing a huge problem for waste disposal and management in the production process of refined palm oil (RPO). In this context, this work aims to systematically investigate the economic analysis of the thermal–catalytic process of crude palm oil (CPO) and palm oil neutralization sludge (PONS). The thermocatalytic processes of CPO and PONS carried out at pilot scale and their economic feasibility were analyzed. The yields of biofuels produced by fractional distillation were also presented. The physicochemical properties of CPO and PONS, as well as those of organic liquid products obtained by the thermal–catalytic process of CPO and PONS were taken into account in the economic analysis. In addition, the chemical composition organic liquid products obtained by thermal–catalytic process of CPO and PONS, as well as its distillation fractions (green gasoline, green kerosene, green light diesel and heavy diesel), used as key factors/indicators on the economic analysis. The analysis of the key factors/indicators from the thermocatalytic processes of CPO and PONS showed economic viability for both crude palm oil (Elaeis guineensis, Jacq) and palm oil neutralization sludge. The minimum fuel selling price (MFSP) obtained in this work for the biofuels was 1.59 USD/L using crude palm oil (CPO) and 1.34 USD/L using palm oil neutralization sludge (PONS). The best breakeven point obtained was of 1.24 USD/L considering the PONS. The sensibility analysis demonstrated that the pyrolysis and distillation yields are the most important variables that affect the minimum fuel-selling price (MFSP) in both economic analyses.

Roadmap for Deployment of Modularized Hydrothermal Liquefaction: Understanding the Impacts of Industry Learning, Optimal Plant Scale, and Delivery Costs on Biofuel Pricing

Hydrothermal liquefaction (HTL) is a promising technology for converting abundant organic wastes into fuels. Previous techno-economic analyses (TEAs) of HTL have been used to estimate the minimum fuel selling price (MFSP) of biofuel products, but these analyses often assume a bespoke plant design where each plant operates under unique process conditions and neglect transportation costs. However, transportation costs must be included in realistic TEAs, and further, a mass-produced fixed-scale modular plant design approach may be more effective than case-by-case plant design, provided that there is sufficient market capacity to benefit from modularization. This study estimates fuel price behavior in the presence of transportation costs and benefits stemming from modular plant design. This analysis indicates that a modular process capable of handling 60 dry tons per day (DTPD) is optimal, resulting in a ∼25% reduction in MFSP (from $4.70/GGE, fully upgraded) at complete market feedstock utilization compared with case-by-case design. The associated cost reductions are attributable to learning benefits and modularization. Several HTL deployment “roadmaps” are then explored, with each roadmap consisting of different periods of case-by-case design followed by adoption of a modularized approach. A period of nonmodular industry growth up to market saturation of ∼7% followed by implementation of modular plant design strikes a balance between the investment risk and learned cost reductions associated with modular plant design. However, if bespoke plants built during this period of nonmodular growth saturate more than 23% of available feedstock, learned cost reductions are significantly diminished. This study points to the potential benefits of modularized and decentralized waste-to-energy processes when the modularization follows an optimal deployment strategy.