Pub Date : 2025-12-12DOI: 10.1016/j.fuel.2025.137982
Shaoming Sun , Ce Fang , Tongqian Guo , Aobo Yan , Lijuan Kong , Yazhou Liu , Yajian Wang
Synergistic treatment of municipal solid waste incineration fly ash (MSWIFA) with Bacillus mucilaginosus and surfactants was investigated to enhance both activation and detoxification. Statistical analysis using JMP Pro showed that while optimal leaching parameters varied across ions, pulp density was consistently the dominant factor. The addition of surfactants, particularly polyoxyethylene ether (PEG), markedly improved the pozzolanic reactivity of MSWIFA, increasing the 90-day activity index from 64.38 % to 101.79 % and reducing the average particle size from 95.29 nm to 47.34 nm. Detoxification efficiency was also enhanced; for Zn, the leaching efficiency reached 81.92 %, a 95.37 % increase compared with untreated MSWIFA. Mechanistic analysis revealed that surfactants facilitated activation and detoxification by inhibiting extracellular polymeric substance (EPS) aggregation, reducing microbial adsorption, and promoting acid accumulation. Heavy metal leaching was controlled not only by elevated acid production but also by competitive adsorption and the formation of surfactant–metal complexes or micelles. Thus, surfactant selection should consider not only dispersing capacity and microbial regulation, but also pH value effects and complexation ability.
{"title":"Detoxification and activation of municipal solid waste incineration fly ash through synergistic treatment with surfactants and Bacillus mucilaginosus: Process optimization and mechanistic analysis","authors":"Shaoming Sun , Ce Fang , Tongqian Guo , Aobo Yan , Lijuan Kong , Yazhou Liu , Yajian Wang","doi":"10.1016/j.fuel.2025.137982","DOIUrl":"10.1016/j.fuel.2025.137982","url":null,"abstract":"<div><div>Synergistic treatment of municipal solid waste incineration fly ash (MSWIFA) with <em>Bacillus mucilaginosus</em> and surfactants was investigated to enhance both activation and detoxification. Statistical analysis using JMP Pro showed that while optimal leaching parameters varied across ions, pulp density was consistently the dominant factor. The addition of surfactants, particularly polyoxyethylene ether (PEG), markedly improved the pozzolanic reactivity of MSWIFA, increasing the 90-day activity index from 64.38 % to 101.79 % and reducing the average particle size from 95.29 nm to 47.34 nm. Detoxification efficiency was also enhanced; for Zn, the leaching efficiency reached 81.92 %, a 95.37 % increase compared with untreated MSWIFA. Mechanistic analysis revealed that surfactants facilitated activation and detoxification by inhibiting extracellular polymeric substance (EPS) aggregation, reducing microbial adsorption, and promoting acid accumulation. Heavy metal leaching was controlled not only by elevated acid production but also by competitive adsorption and the formation of surfactant–metal complexes or micelles. Thus, surfactant selection should consider not only dispersing capacity and microbial regulation, but also pH value effects and complexation ability.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137982"},"PeriodicalIF":7.5,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1016/j.fuel.2025.137934
Nico Thanheuser , Sebastian Püschel , Andreas J. Vorholt , Jesús Esteban
5-hydroxymethylfurfural (HMF) and furfural are highly praised chemicals in the biofuel context, derived from fructose (Fruc) and xylose (Xyl), respectively. Here a H2O/MIBK biphasic system is used as a green approach to extract in situ the furans generated in each reaction, thereby mitigating undesired reactions of rehydration and/or self-condensation to humins. The production of HMF and furfural is performed through two approaches: an autocatalytic reaction and using a thermoresponsive catalyst, hence facilitating recycling. Ethylenediaminetetraacetic acid (EDTA) was identified as a thermoresponsive organic acid with high recyclability (>97 % catalytic activity recovery after 5 cycles and regeneration) acting as homogeneous catalyst under reaction conditions. After proving the lack of mass transfer limitations and considering the reaction networks and mass balances for HMF and Fur production, macrokinetic models were proposed to describe the two reactions in a biphasic medium. In the autocatalytic regime, the values of the activation energy of the dehydration of Fruc to HMF and Xyl to furfural were 155.72 ± 12.84 kJ mol−1 and 138.09 ± 7.45 kJ mol−1, respectively, whereas in the presence of EDTA as catalyst, the dehydration of Fruc to HMF showed a value of 139.12 ± 8.40 kJ mol−1 and that of Xyl to furfural of 130.33 ± 9.49 kJ mol−1.
{"title":"5-hydroxymethylfurfural and furfural production in biphasic systems: kinetic studies of autocatalytic operation and using EDTA as thermoresponsive catalyst","authors":"Nico Thanheuser , Sebastian Püschel , Andreas J. Vorholt , Jesús Esteban","doi":"10.1016/j.fuel.2025.137934","DOIUrl":"10.1016/j.fuel.2025.137934","url":null,"abstract":"<div><div>5-hydroxymethylfurfural (HMF) and furfural are highly praised chemicals in the biofuel context, derived from fructose (Fruc) and xylose (Xyl), respectively. Here a H<sub>2</sub>O/MIBK biphasic system is used as a green approach to extract <em>in situ</em> the furans generated in each reaction, thereby mitigating undesired reactions of rehydration and/or self-condensation to humins. The production of HMF and furfural is performed through two approaches: an autocatalytic reaction and using a thermoresponsive catalyst, hence facilitating recycling. Ethylenediaminetetraacetic acid (EDTA) was identified as a thermoresponsive organic acid with high recyclability (>97 % catalytic activity recovery after 5 cycles and regeneration) acting as homogeneous catalyst under reaction conditions. After proving the lack of mass transfer limitations and considering the reaction networks and mass balances for HMF and Fur production, macrokinetic models were proposed to describe the two reactions in a biphasic medium. In the autocatalytic regime, the values of the activation energy of the dehydration of Fruc to HMF and Xyl to furfural were 155.72 ± 12.84 kJ mol<sup>−1</sup> and 138.09 ± 7.45 kJ mol<sup>−1</sup>, respectively, whereas in the presence of EDTA as catalyst, the dehydration of Fruc to HMF showed a value of 139.12 ± 8.40 kJ mol<sup>−1</sup> and that of Xyl to furfural of 130.33 ± 9.49 kJ mol<sup>−1</sup>.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137934"},"PeriodicalIF":7.5,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ammonia (NH3)-hydrogen (H2) blended fuel, a novel form of clean energy devoid of carbon, poses significant explosion hazards during practical application. This study systematically investigated the explosion suppression effects of a novel suppressant, ammonium polyphosphate-modified gel dry water (AGDW), on NH3-H2-air mixtures (10% and 30% H2 by volume) using a self-constructed transparent horizontal pipeline, with the suppression mechanism revealed through Chemkin simulations. The experimental results revealed that for premixed gases with H2 blending ratios of 10% and 30%, the addition of 10 g AGDW significantly suppressed explosion dynamics: the peak flame temperature (Tp) decreased by 97.7% and 98.1%, while the maximum explosion pressure (Pmax) declined by 85.0% and 87.0%, respectively, compared to unsuppressed conditions. Notably, flame propagation was completely halted at the suppression zone. Simulation results, analyzed from the perspectives of product generation, key radical concentrations, and temperature sensitivity of reactions, indicate that the thermal decomposition products of AGDW, namely HPO3, HOPO, and PO2, effectively scavenge H, OH, and O radicals via cyclic pathways, thereby interrupting chain reactions and achieving chemical suppression. This work provides valuable experimental data and theoretical insight for the safe application of NH3-H2 fuel and offers a novel approach for mitigating premixed gas explosion risk.
氨(NH3)-氢（H2）混合燃料是一种新型的无碳清洁能源，在实际应用中存在较大的爆炸危险。本研究采用自制透明水平管道，系统研究了聚磷酸铵改性凝胶干水（AGDW）对nh3 -H2-空气混合物（H2体积比为10%和30%）的抑爆效果，并通过Chemkin模拟揭示了抑爆机理。实验结果表明，在H2掺比为10%和30%的预混气体中，添加10 g AGDW显著抑制了爆炸动力学，火焰峰值温度（Tp）比未抑制条件降低了97.7%和98.1%，最大爆炸压力（Pmax）分别降低了85.0%和87.0%。值得注意的是，火焰的传播完全停止在抑制区。从产物生成、关键自由基浓度、反应温度敏感性等方面分析模拟结果表明，AGDW热分解产物HPO3、HOPO、PO2通过循环途径有效清除H、OH、O自由基，从而中断链式反应，实现化学抑制。该工作为NH3-H2燃料的安全应用提供了有价值的实验数据和理论见解，并为减轻预混气体爆炸风险提供了新的途径。
{"title":"Experimental and numerical study on the suppression of ammonia-hydrogen mixture explosions by ammonium polyphosphate-modified gel dry water","authors":"Yu Du, Chuyuan Huang, Dongyang Qiu, Xuxu Sun, Hao Zeng, Xianfeng Chen","doi":"10.1016/j.fuel.2025.137938","DOIUrl":"10.1016/j.fuel.2025.137938","url":null,"abstract":"<div><div>Ammonia (NH<sub>3</sub>)-hydrogen (H<sub>2</sub>) blended fuel, a novel form of clean energy devoid of carbon, poses significant explosion hazards during practical application. This study systematically investigated the explosion suppression effects of a novel suppressant, ammonium polyphosphate-modified gel dry water (AGDW), on NH<sub>3</sub>-H<sub>2</sub>-air mixtures (10% and 30% H<sub>2</sub> by volume) using a self-constructed transparent horizontal pipeline, with the suppression mechanism revealed through Chemkin simulations. The experimental results revealed that for premixed gases with H<sub>2</sub> blending ratios of 10% and 30%, the addition of 10 g AGDW significantly suppressed explosion dynamics: the peak flame temperature (<em>T</em><sub>p</sub>) decreased by 97.7% and 98.1%, while the maximum explosion pressure (<em>P</em><sub>max</sub>) declined by 85.0% and 87.0%, respectively, compared to unsuppressed conditions. Notably, flame propagation was completely halted at the suppression zone. Simulation results, analyzed from the perspectives of product generation, key radical concentrations, and temperature sensitivity of reactions, indicate that the thermal decomposition products of AGDW, namely HPO<sub>3</sub>, HOPO, and PO<sub>2</sub>, effectively scavenge H, OH, and O radicals via cyclic pathways, thereby interrupting chain reactions and achieving chemical suppression. This work provides valuable experimental data and theoretical insight for the safe application of NH<sub>3</sub>-H<sub>2</sub> fuel and offers a novel approach for mitigating premixed gas explosion risk.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137938"},"PeriodicalIF":7.5,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.fuel.2025.137835
Song Yu , Dai Xuguang , Zhang Yu , Wang Meng , Zheng Sijian , Feng Guangjun
The curvature of PAH (polycyclic aromatic hydrocarbons) plays a critical role on structural alignment of anthracite, however, its potential impacts on selective diffusion of CO2/CH4 remains unclear. Thus, the curvature distribution and its impact on diffusion of CO2/CH4 in vitrinite-rich anthracite of Yangquan coalfield were investigated via both experiment and molecular simulation. The quantitative results of PAH curvature suggested that curved PAHs account for 52–68 % (63 % in average) of total PAHs and PAH frequency increases with the increasing curvature, resulting in bulk amount of highly-curved PAHs, fewer middle-curved ones and very few low-curved types. For single component diffusion of CH4 or CO2, Dt (transport diffusion coefficient) follows the order of low- > middle-> highly-curved anthracite, indicating that PAH curvature could delay the CH4/CO2 diffusion. The calculation results of ΔE (diffusion activation energy) suggested that curvature of PAH increases the energy barrier of gas diffusion. Coal reservoirs of high PAH curvature possesses high selectivity of adsorption and diffusion for CO2 over CH4, favorable for the both adsorption replacement of CH4 and CO2 capture and storage. This paper provides theoretical insights for impacts of PAH curvature on CO2/CH4 diffusion and relates the potential applications of low-, middle- and highly-curved anthracite for CO2-ECBM (CO2 enhanced coalbed methane).
{"title":"Curvature of PAH and its impact on selective diffusion of CH4/CO2 in vitrinite-rich anthracite of Yanquan coalfield","authors":"Song Yu , Dai Xuguang , Zhang Yu , Wang Meng , Zheng Sijian , Feng Guangjun","doi":"10.1016/j.fuel.2025.137835","DOIUrl":"10.1016/j.fuel.2025.137835","url":null,"abstract":"<div><div>The curvature of PAH (polycyclic aromatic hydrocarbons) plays a critical role on structural alignment of anthracite, however, its potential impacts on selective diffusion of CO<sub>2</sub>/CH<sub>4</sub> remains unclear. Thus, the curvature distribution and its impact on diffusion of CO<sub>2</sub>/CH<sub>4</sub> in vitrinite-rich anthracite of Yangquan coalfield were investigated via both experiment and molecular simulation. The quantitative results of PAH curvature suggested that curved PAHs account for 52–68 % (63 % in average) of total PAHs and PAH frequency increases with the increasing curvature, resulting in bulk amount of highly-curved PAHs, fewer middle-curved ones and very few low-curved types. For single component diffusion of CH<sub>4</sub> or CO<sub>2</sub>, D<sup>t</sup> (transport diffusion coefficient) follows the order of low- > middle-> highly-curved anthracite, indicating that PAH curvature could delay the CH<sub>4</sub>/CO<sub>2</sub> diffusion. The calculation results of ΔE (diffusion activation energy) suggested that curvature of PAH increases the energy barrier of gas diffusion. Coal reservoirs of high PAH curvature possesses high selectivity of adsorption and diffusion for CO<sub>2</sub> over CH<sub>4</sub>, favorable for the both adsorption replacement of CH<sub>4</sub> and CO<sub>2</sub> capture and storage. This paper provides theoretical insights for impacts of PAH curvature on CO<sub>2</sub>/CH<sub>4</sub> diffusion and relates the potential applications of low-, middle- and highly-curved anthracite for CO<sub>2</sub>-ECBM (CO<sub>2</sub> enhanced coalbed methane).</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137835"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.fuel.2025.137882
Zihao Gao , Fei Wang , Junfeng Feng , Haifei Zhang , Fumin Wang
The selective hydrogenation of furfural to furfuryl alcohol is a key transformation in biomass valorization, enabling the production of high-value chemicals from renewable feedstocks. In this work, a monometallic cobalt nanoparticle (Co-NAP) catalyst was synthesized via controlled pyrolysis of cobalt-based metal–organic frameworks (Co-MOFs). By systematically tuning the crystallization temperature of Co-MOFs and the subsequent pyrolysis temperature, the dispersion of Co nanoparticles and the density of Lewis acid sites were finely modulated. The resulting Co-NAP catalysts were comprehensively characterized by XRD, XPS, N2 physical sorption, CO pulse chemisorption, and Py-IR. Catalytic evaluation revealed that Co-NAP-120–500 exhibited superior activity, achieving 100 % furfuryl alcohol conversion and a 93.8 % furfuryl alcohol yield under optimized conditions (150 ℃, 2.0 MPa H2, 6 h). The remarkable catalytic performance arises from the synergy of highly dispersed Co⁰ sites that activate H2, abundant Lewis acid sites that polarize the C=O bond, and well-developed mesopores that facilitate mass transfer. Overall, this study provides mechanistic insight and practical guidelines for the rational design of MOF-derived cobalt catalysts for the selective hydrogenation of biomass-derived aldehydes.
{"title":"Structure-activity relationship of MOF-derived cobalt catalyst in selective hydrogenation of furfural to furfuryl alcohol","authors":"Zihao Gao , Fei Wang , Junfeng Feng , Haifei Zhang , Fumin Wang","doi":"10.1016/j.fuel.2025.137882","DOIUrl":"10.1016/j.fuel.2025.137882","url":null,"abstract":"<div><div>The selective hydrogenation of furfural to furfuryl alcohol is a key transformation in biomass valorization, enabling the production of high-value chemicals from renewable feedstocks. In this work, a monometallic cobalt nanoparticle (Co-NAP) catalyst was synthesized via controlled pyrolysis of cobalt-based metal–organic frameworks (Co-MOFs). By systematically tuning the crystallization temperature of Co-MOFs and the subsequent pyrolysis temperature, the dispersion of Co nanoparticles and the density of Lewis acid sites were finely modulated. The resulting Co-NAP catalysts were comprehensively characterized by XRD, XPS, N<sub>2</sub> physical sorption, CO pulse chemisorption, and Py-IR. Catalytic evaluation revealed that Co-NAP-120–500 exhibited superior activity, achieving 100 % furfuryl alcohol conversion and a 93.8 % furfuryl alcohol yield under optimized conditions (150 ℃, 2.0 MPa H<sub>2</sub>, 6 h). The remarkable catalytic performance arises from the synergy of highly dispersed Co⁰ sites that activate H<sub>2</sub>, abundant Lewis acid sites that polarize the C=O bond, and well-developed mesopores that facilitate mass transfer. Overall, this study provides mechanistic insight and practical guidelines for the rational design of MOF-derived cobalt catalysts for the selective hydrogenation of biomass-derived aldehydes.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137882"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.fuel.2025.137984
Qiuxiang Yao , Lei He , Hongchuan Liu , Duo Ma , Chuanfeng Huang , Ming Sun
Solvent swelling, which can adjust the molecular and chemical structure of coal, serves as an important technique for studying its structure, pyrolysis behavior, and the mechanisms of product control. This study employed high-temperature swelling of demineralized low-rank coal (Shendong coal, RD) using six solvents (tetrahydrofuran, ethanol, benzene, acetic acid, acetone, and n-heptane) at 150 °C. This enhanced solvent-coal interaction was combined with multi-step pyrolysis using a fast pyrolysis–gas chromatography/mass spectrometry (PY-GC/MS) instrument (50–150 °C, 150–200 °C, 250–250 °C, 250–650 °C) to capture residual solvents and solvent-leached substances during swelling, thereby elucidating the specific role of solvent swelling. Calculations of pyrolysis kinetics for the high-temperature-swelling coal samples revealed that, based on changes in activation energy required for different pyrolysis stages of the swollen samples, the solvents could be approximately grouped into three sets: G1 (tetrahydrofuran and ethanol), G2 (acetone and benzene), and G3 (acetic acid and n-heptane), with corresponding Ea of G1 (110 kJ·mol−1) > G2 (100 kJ·mol−1) > RD = G3 (89 kJ·mol−1). This indicates that the swelling effects of different solvents occur in distinct pyrolysis stages during high-temperature swelling. The substantial products detected in the 50–150 °C pyrolysis segment serve as direct evidence of solvent-coal interactions. This study elucidates the synergistic effects between different solvents and high temperature, providing theoretical support for the high-temperature swelling and pyrolysis characteristics of low-rank coal. It also offers important references for direct coal liquefaction and coal-oil co-processing.
{"title":"The swelling behavior of six typical solvents on low-rank coal at 150 ℃ and their influence on the pyrolysis characteristics of coal","authors":"Qiuxiang Yao , Lei He , Hongchuan Liu , Duo Ma , Chuanfeng Huang , Ming Sun","doi":"10.1016/j.fuel.2025.137984","DOIUrl":"10.1016/j.fuel.2025.137984","url":null,"abstract":"<div><div>Solvent swelling, which can adjust the molecular and chemical structure of coal, serves as an important technique for studying its structure, pyrolysis behavior, and the mechanisms of product control. This study employed high-temperature swelling of demineralized low-rank coal (Shendong coal, RD) using six solvents (tetrahydrofuran, ethanol, benzene, acetic acid, acetone, and <em>n</em>-heptane) at 150 °C. This enhanced solvent-coal interaction was combined with multi-step pyrolysis using a fast pyrolysis–gas chromatography/mass spectrometry (PY-GC/MS) instrument (50–150 °C, 150–200 °C, 250–250 °C, 250–650 °C) to capture residual solvents and solvent-leached substances during swelling, thereby elucidating the specific role of solvent swelling. Calculations of pyrolysis kinetics for the high-temperature-swelling coal samples revealed that, based on changes in activation energy required for different pyrolysis stages of the swollen samples, the solvents could be approximately grouped into three sets: G1 (tetrahydrofuran and ethanol), G2 (acetone and benzene), and G3 (acetic acid and <em>n</em>-heptane), with corresponding <em>E</em><sub>a</sub> of G1 (110 kJ·mol<sup>−1</sup>) > G2 (100 kJ·mol<sup>−1</sup>) > RD = G3 (89 kJ·mol<sup>−1</sup>). This indicates that the swelling effects of different solvents occur in distinct pyrolysis stages during high-temperature swelling. The substantial products detected in the 50–150 °C pyrolysis segment serve as direct evidence of solvent-coal interactions. This study elucidates the synergistic effects between different solvents and high temperature, providing theoretical support for the high-temperature swelling and pyrolysis characteristics of low-rank coal. It also offers important references for direct coal liquefaction and coal-oil co-processing.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137984"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.fuel.2025.137849
Doaa H. Khalaf , Qusay Hassan , Hassan Falah Fakhruldeen , Feryal Ibrahim Jabbar , Saiful Islam , Quadri Noorulhasan Naveed , Ayodele Lasisi , Sadiq N. Henedy , Sameer Algburi
This study introduces a novel approach to sustainable fuel production through the integrated application of plasma gasification, Fischer–Tropsch (FT) synthesis, and solar-powered electrolysis, focusing on the co-valorization of medical waste (MW) and biomass waste (BMW). Addressing critical challenges related to waste accumulation and energy security, the system transforms complex waste streams into synthetic e-fuels by optimizing syngas composition and hydrogen integration. In the case study of Iraq where over 4.12 million tonnes of solid waste were landfilled in 2023, including substantial medical and municipal waste this approach offers a viable solution for resource recovery. Plasma gasification converts MW and BMW into syngas, which is refined and processed for CO2 capture using an MDEA-based absorption system. Solar-derived hydrogen, produced through a PEM electrolyzer, is integrated to achieve the optimal H2/CO ratio for FT synthesis. System modeling was conducted in Aspen Plus and MATLAB, with a Genetic Algorithm (GA) employed to optimize parameters for hydrogen yield enhancement. Four biomass-to-medical waste blending ratios (0.2 to 0.8) were tested. The highest-performing scenario (0.8 ratio) achieved a hydrogen mole fraction of 45.78 %, a syngas flowrate of 8,670 Nm3/h, hydrogen production of 1,300 kg/h, and a peak FT conversion efficiency of 55.8 %. Liquid fuel yield reached 1,360 kg/h, with diesel comprising the dominant product at 519 kg/h and 22,317 MJ/h of energy output. Hydrogen utilization efficiency increased to 87.5 %, and energy cost for hydrogen electrolysis decreased to 54.2 MJ/kg. Economic evaluation revealed strong financial viability at scale, with the highest scenario yielding a net present value (NPV) of $43.71 million, return on investment (ROI) of 16.48 %, and a payback period reduced to 14.93 years. Environmental analysis showed significant reductions in CO2 emissions (down to 19.3 %) and improvements in carbon-to-fuel efficiency (up to 71.2 %), with stable solid residue losses. High-temperature plasma gasification was chosen because it can safely process infectious medical waste and delivers a tar-lean syngas ideally suited for downstream Fischer-Tropsch conversion.
{"title":"Waste biomass to e-fuels via integrated plasma gasification and Solar-Assisted FT synthesis","authors":"Doaa H. Khalaf , Qusay Hassan , Hassan Falah Fakhruldeen , Feryal Ibrahim Jabbar , Saiful Islam , Quadri Noorulhasan Naveed , Ayodele Lasisi , Sadiq N. Henedy , Sameer Algburi","doi":"10.1016/j.fuel.2025.137849","DOIUrl":"10.1016/j.fuel.2025.137849","url":null,"abstract":"<div><div>This study introduces a novel approach to sustainable fuel production through the integrated application of plasma gasification, Fischer–Tropsch (FT) synthesis, and solar-powered electrolysis, focusing on the co-valorization of medical waste (MW) and biomass waste (BMW). Addressing critical challenges related to waste accumulation and energy security, the system transforms complex waste streams into synthetic e-fuels by optimizing syngas composition and hydrogen integration. In the case study of Iraq where over 4.12 million tonnes of solid waste were landfilled in 2023, including substantial medical and municipal waste this approach offers a viable solution for resource recovery. Plasma gasification converts MW and BMW into syngas, which is refined and processed for CO<sub>2</sub> capture using an MDEA-based absorption system. Solar-derived hydrogen, produced through a PEM electrolyzer, is integrated to achieve the optimal H<sub>2</sub>/CO ratio for FT synthesis. System modeling was conducted in Aspen Plus and MATLAB, with a Genetic Algorithm (GA) employed to optimize parameters for hydrogen yield enhancement. Four biomass-to-medical waste blending ratios (0.2 to 0.8) were tested. The highest-performing scenario (0.8 ratio) achieved a hydrogen mole fraction of 45.78 %, a syngas flowrate of 8,670 Nm<sup>3</sup>/h, hydrogen production of 1,300 kg/h, and a peak FT conversion efficiency of 55.8 %. Liquid fuel yield reached 1,360 kg/h, with diesel comprising the dominant product at 519 kg/h and 22,317 MJ/h of energy output. Hydrogen utilization efficiency increased to 87.5 %, and energy cost for hydrogen electrolysis decreased to 54.2 MJ/kg. Economic evaluation revealed strong financial viability at scale, with the highest scenario yielding a net present value (NPV) of $43.71 million, return on investment (ROI) of 16.48 %, and a payback period reduced to 14.93 years. Environmental analysis showed significant reductions in CO<sub>2</sub> emissions (down to 19.3 %) and improvements in carbon-to-fuel efficiency (up to 71.2 %), with stable solid residue losses. High-temperature plasma gasification was chosen because it can safely process infectious medical waste and delivers a tar-lean syngas ideally suited for downstream Fischer-Tropsch conversion.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137849"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Supercritical hydrocarbon fuels, achieved at high pressure and temperature, exhibit both liquid-like density and gas-like diffusivity, offering enhanced mixing and combustion efficiency in scramjet engines. This study investigates the near-field behavior of supercritical kerosene jets injected into a Mach 1.94 supersonic crossflow under cold-flow conditions. It aims to give a correlation for penetration height of upstream, non-upstream and the mean mode, of the supercritical jet injected, in terms of easily measurable values, viz., stagnation temperature and pressure upstream of the injector. High-speed schlieren imaging was employed to capture the evolving shock structures, shear layers, and jet morphology. Using a nondimensional parameter based on injection and freestream conditions, generalized correlations were developed to describe jet penetration across the tested operating range. The findings offer a practical framework for supercritical fuel behavior, for designing injector configurations in high-speed propulsion systems.
{"title":"Penetration of supercritical kerosene jet in supersonic crossflow: Effects of injection stagnation temperature and pressure","authors":"Gagana Satyanarayan, Eshaan Raj, T.M. Muruganandam","doi":"10.1016/j.fuel.2025.137977","DOIUrl":"10.1016/j.fuel.2025.137977","url":null,"abstract":"<div><div>Supercritical hydrocarbon fuels, achieved at high pressure and temperature, exhibit both liquid-like density and gas-like diffusivity, offering enhanced mixing and combustion efficiency in scramjet engines. This study investigates the near-field behavior of supercritical kerosene jets injected into a Mach 1.94 supersonic crossflow under cold-flow conditions. It aims to give a correlation for penetration height of upstream, non-upstream and the mean mode, of the supercritical jet injected, in terms of easily measurable values, viz., stagnation temperature and pressure upstream of the injector. High-speed schlieren imaging was employed to capture the evolving shock structures, shear layers, and jet morphology. Using a nondimensional parameter based on injection and freestream conditions, generalized correlations were developed to describe jet penetration across the tested operating range. The findings offer a practical framework for supercritical fuel behavior, for designing injector configurations in high-speed propulsion systems.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137977"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.fuel.2025.137948
Xu Shao , Bao Qu , Botao Qin , Quanlin Shi , Fujun Zhao , Shibo Xu , Song Ren , Mingyue Weng
Thermal metamorphism induced by magmatic intrusion significantly alters the physicochemical structure of coal, consequently exacerbating its spontaneous combustion risk. This study investigates the low-temperature oxygen absorption-oxidation kinetics and pore structure response of coal across a magmatic thermally metamorphic gradient (MTMG). Field-sampled coals were analyzed using low-temperature oxygen absorption tests, temperature-programmed oxidation experiments, and N2/CO2 isothermal adsorption, revealing the regulatory mechanism of MTMG on oxygen absorption capacity, apparent activation energy, and pore structure evolution. MTMG induces significant pore structure differentiation. Thermally deep-metamorphic coal exhibits 55.6 % and 13.3 % increases in mesopore and micropore volume, respectively. It enhances oxygen diffusion towards active sites and elevates oxygen absorption capacity, increasing from 2.92 % to 3.80 %, accompanied by a rise in absorption rate. The pore response to low-temperature oxidation exhibits temperature dependence and is regulated by metamorphic grade. Oxidation generally causes mesopore contraction, while intense thermal metamorphism remarkably suppresses this effect. Micropore volume proportion and homogeneity progressively increase during oxidation. Thermally altered coal sustains oxidation reactions within small pores (<5 nm) by maintaining highly stable mesopore channels and high-density micropore active sites. A synergistic relationship links pore structure evolution with oxidation characteristics. Micropore expansion increases active site density, boosting oxygen absorption capacity, and the large pore diameter segment in mesopore shows a significant positive correlation with apparent activation energy, collectively lowering it. This synergy promotes the coal-oxygen reaction, entering an accelerated oxidation stage. Thermally deep-metamorphic coal, characterized by the highest oxygen absorption, lowest activation energy, largest micropore volume, and most stable mesopore structure, constitutes the critical risk zone for spontaneous combustion under magmatic intrusion. These findings reveal the microscopic driver behind the elevated spontaneous combustion propensity of thermally altered coal, providing theoretical foundations for targeted spontaneous combustion prevention strategies in magmatic intrusion zones.
{"title":"Pore response to the oxidation of gas coal across a magmatic thermally metamorphic gradient","authors":"Xu Shao , Bao Qu , Botao Qin , Quanlin Shi , Fujun Zhao , Shibo Xu , Song Ren , Mingyue Weng","doi":"10.1016/j.fuel.2025.137948","DOIUrl":"10.1016/j.fuel.2025.137948","url":null,"abstract":"<div><div>Thermal metamorphism induced by magmatic intrusion significantly alters the physicochemical structure of coal, consequently exacerbating its spontaneous combustion risk. This study investigates the low-temperature oxygen absorption-oxidation kinetics and pore structure response of coal across a magmatic thermally metamorphic gradient (MTMG). Field-sampled coals were analyzed using low-temperature oxygen absorption tests, temperature-programmed oxidation experiments, and N<sub>2</sub>/CO<sub>2</sub> isothermal adsorption, revealing the regulatory mechanism of MTMG on oxygen absorption capacity, apparent activation energy, and pore structure evolution. MTMG induces significant pore structure differentiation. Thermally deep-metamorphic coal exhibits 55.6 % and 13.3 % increases in mesopore and micropore volume, respectively. It enhances oxygen diffusion towards active sites and elevates oxygen absorption capacity, increasing from 2.92 % to 3.80 %, accompanied by a rise in absorption rate. The pore response to low-temperature oxidation exhibits temperature dependence and is regulated by metamorphic grade. Oxidation generally causes mesopore contraction, while intense thermal metamorphism remarkably suppresses this effect. Micropore volume proportion and homogeneity progressively increase during oxidation. Thermally altered coal sustains oxidation reactions within small pores (<5 nm) by maintaining highly stable mesopore channels and high-density micropore active sites. A synergistic relationship links pore structure evolution with oxidation characteristics. Micropore expansion increases active site density, boosting oxygen absorption capacity, and the large pore diameter segment in mesopore shows a significant positive correlation with apparent activation energy, collectively lowering it. This synergy promotes the coal-oxygen reaction, entering an accelerated oxidation stage. Thermally deep-metamorphic coal, characterized by the highest oxygen absorption, lowest activation energy, largest micropore volume, and most stable mesopore structure, constitutes the critical risk zone for spontaneous combustion under magmatic intrusion. These findings reveal the microscopic driver behind the elevated spontaneous combustion propensity of thermally altered coal, providing theoretical foundations for targeted spontaneous combustion prevention strategies in magmatic intrusion zones.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137948"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.fuel.2025.137995
Pengxiang Li , Jiawei Wang , Xun Mao , Hanting Huang , Zequn Zhang , Hao Yuan , Tong Wang , Guoqing Shen , Zhitan Liu , Yongsheng Zhang
In large-scale wind and solar renewable energy applications, hydrogen production via water electrolysis provides effective energy storage. Coupled with pure hydrogen and pure oxygen combustion, this method significantly mitigates renewable energy intermittency. However, the extremely high flame propagation speed and inherent risks of pure H2/O2 combustion pose significant safety challenges and remain insufficiently investigated experimentally. In this paper, the combustion characteristics of pure hydrogen and pure oxygen in a micro-mixing nozzle unit under steam dilution are systematically investigated. A safe three-stage ignition strategy was first developed, involving a progressive transition from wet-air combustion to oxygen-enriched combustion, and ultimately to pure-oxygen combustion. For hydrogen–oxygen flames, variations in dilution ratio, equivalence ratio, and thermal power significantly influenced flame structure and temperature distribution. The micro-mixing nozzle unit exhibits favorable burnout performance, with the combustion efficiency of pure hydrogen and pure oxygen consistently maintained above 99.6 % even under operating conditions close to flashback. During flashback, the flame undergoes rapid contraction and exhibits sustained oscillations within the nozzle tube, with a marked increase in amplitude observed at frequencies of 235 Hz and 669 Hz. By optimizing the equivalence ratio and steam dilution ratio, and thereby regulating nozzle exit velocity and adiabatic flame temperature, the risk of flashback can be significantly reduced. At a thermal power of 20 kW, within the equivalence ratio range of 0.75–0.95, flashback can be effectively prevented by maintaining a nozzle exit velocity of no less than 58 m/s and limiting the adiabatic flame temperature to no more than 1897 K.
{"title":"Combustion characteristics of hydrogen and oxygen micro-mixing flame with steam dilution","authors":"Pengxiang Li , Jiawei Wang , Xun Mao , Hanting Huang , Zequn Zhang , Hao Yuan , Tong Wang , Guoqing Shen , Zhitan Liu , Yongsheng Zhang","doi":"10.1016/j.fuel.2025.137995","DOIUrl":"10.1016/j.fuel.2025.137995","url":null,"abstract":"<div><div>In large-scale wind and solar renewable energy applications, hydrogen production via water electrolysis provides effective energy storage. Coupled with pure hydrogen and pure oxygen combustion, this method significantly mitigates renewable energy intermittency. However, the extremely high flame propagation speed and inherent risks of pure H<sub>2</sub>/O<sub>2</sub> combustion pose significant safety challenges and remain insufficiently investigated experimentally. In this paper, the combustion characteristics of pure hydrogen and pure oxygen in a micro-mixing nozzle unit under steam dilution are systematically investigated. A safe three-stage ignition strategy was first developed, involving a progressive transition from wet-air combustion to oxygen-enriched combustion, and ultimately to pure-oxygen combustion. For hydrogen–oxygen flames, variations in dilution ratio, equivalence ratio, and thermal power significantly influenced flame structure and temperature distribution. The micro-mixing nozzle unit exhibits favorable burnout performance, with the combustion efficiency of pure hydrogen and pure oxygen consistently maintained above 99.6 % even under operating conditions close to flashback. During flashback, the flame undergoes rapid contraction and exhibits sustained oscillations within the nozzle tube, with a marked increase in amplitude observed at frequencies of 235 Hz and 669 Hz. By optimizing the equivalence ratio and steam dilution ratio, and thereby regulating nozzle exit velocity and adiabatic flame temperature, the risk of flashback can be significantly reduced. At a thermal power of 20 kW, within the equivalence ratio range of 0.75–0.95, flashback can be effectively prevented by maintaining a nozzle exit velocity of no less than 58 m/s and limiting the adiabatic flame temperature to no more than 1897 K.</div></div>","PeriodicalId":325,"journal":{"name":"Fuel","volume":"410 ","pages":"Article 137995"},"PeriodicalIF":7.5,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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