BioEnergy Research最新文献

{"title":"Drivers of Biomass Yield and Climate Benefits in Short Rotation Forestry: A Semi-Quantitative Review of 80 Years of German Research","authors":"Leonardo Amthauer Gallardo,&nbsp;Andrea Biertümpfel,&nbsp;Andreas Gurgel,&nbsp;Kerstin Jäkel","doi":"10.1007/s12155-026-10978-5","DOIUrl":"10.1007/s12155-026-10978-5","url":null,"abstract":"<div><p>This review compiles experimental and empirical evidence from Germany since the 1940s, revealing relationships between management drivers and yield. Two- to three-year cycles produced the highest biomass yields (9.8 Mg ha⁻¹ a⁻¹), outperforming longer rotations of 7–10 (6.2 Mg ha⁻¹ a⁻¹) and ~ 20 years (5.8 Mg ha⁻¹ a⁻¹), likely due to higher shoot density in coppiced systems. Poplar achieved the highest yields, though willow nearly matched in shorter cycles. In four- to six-year cycles, poplar yields (9.5 Mg ha⁻¹ a⁻¹) were almost three times those of birch and alder, and about 66% higher than willow. Black locust (5.0 Mg ha⁻¹ a⁻¹) reached moderately lower yields than poplar (7.2 Mg ha⁻¹ a⁻¹) in ten-year cycles. Poplar and willow coppice systems remain productive for over 20 years, with mean annual increment rising until root age 21 and current annual increment peaking at 15–18 years. Recent models enable more precise site and yield assessment, with plant-available water-holding capacity and precipitation emerging as key factors. In newly established systems, poplar single-stem plantations can sequester up to 2.9 Mg C ha⁻¹ a⁻¹, about 2.5 times more than young forests, while coppiced systems can reach 5.1 Mg C ha⁻¹ a⁻¹, up to six times more, making them valuable for climate mitigation when biomass enters long-lived uses. The strength of coppice systems lies in their contribution to renewable energy and as a source of raw material. With decades of trials, short rotation systems are proven mature options for biomass production and carbon mitigation. These findings underscore the need to re-evaluate the limited political attention given to short rotation systems.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing Biochar for Phenol Mitigation and Methane Enhancement in Rice Mill Waste Co-Digestion","authors":"Nagarjuna Kandagatla,&nbsp;Sridhar Pilli,&nbsp;Polisetty Venkateswara Rao,&nbsp;R. D. Tyagi","doi":"10.1007/s12155-026-10988-3","DOIUrl":"10.1007/s12155-026-10988-3","url":null,"abstract":"<div>\u0000 \u0000 <p>Parboiled rice milling generated phenol-rich wastewater and rice husk, creating environmental risks but offering biogas potential—addressing this challenge was essential for sustainable agro-industrial waste management. This study investigated the kinetic performance, energy balance, and economic feasibility of biochar-assisted anaerobic co-digestion (BC-ACoD) of parboiled rice mill wastewater (PRMWW) and rice straw (RS). Fecal sludge-derived biochar was optimized in terms of particle size and dosage to simultaneously adsorb inhibitory phenolic compounds and enhance methanogenesis. Biochar size 300–150 μm fraction and 6 g/L dosage delivering the best biomethane performance. Batch anaerobic digestion tests and kinetic modeling using first-order and modified Gompertz equations demonstrated that biochar addition increased ultimate methane potential and production rates, while maintaining process stability. An energy balance was developed that accounted for RS chopping, transportation, wastewater heating to mesophilic conditions, heat losses, and biochar production, expressed per unit of volatile solids (VS). The analysis showed that conventional ACoD of PRMWW and RS yielded an energy ratio of 1.03, whereas BC-ACoD improved the energy ratio to 1.14, with total energy outputs of 1107.5 and 1217.5 kWh/Mg VS, respectively. In contrast, mono-digestion of RS and PRMWW alone exhibited energy ratios of 0.34 and 0.21 and negative net energy, highlighting their limited feasibility as standalone options. Overall, the findings confirmed that integrating optimized biochar into ACoD of PRMWW and RS enabled phenol control, higher methane recovery, and a positive net energy gain of 143.51 kWh/Mg VS, supporting decentralized, circular waste-to-energy applications in rice-processing industries.</p>\u0000 </div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147441103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cerium–Impregnated Rice Husk–Derived Catalysts for Fatty Acid Esterification Using Methyl Acetate","authors":"Mariana Albarello,&nbsp;Ana Luísa Seeger Machado,&nbsp;Christian Hulteberg,&nbsp;Heveline Enzweiler,&nbsp;Fernanda de Castilhos","doi":"10.1007/s12155-026-10970-z","DOIUrl":"10.1007/s12155-026-10970-z","url":null,"abstract":"<div>\u0000 \u0000 <p>This study reports the synthesis and characterization of heterogeneous acid catalysts derived from rice husk biochar, modified by sulfonation and Ce(NO₃)₃·6H₂O (cerium (III) nitrate hexahydrate) impregnation, for fatty acid esterification using methyl acetate as a glycerol-free reaction route. The research aims to valorize agricultural residues as renewable and sustainable precursors for solid acid catalysts, reducing the dependence on fossil-based materials and supporting cleaner energy technologies. The sulfonation process effectively introduced Brønsted and Lewis acid sites, whereas cerium incorporation enhanced the structural and acidic properties of the material. Comprehensive physicochemical characterization through XRF, FTIR, BET, and SEM analyses confirmed the successful incorporation of both sulfonic and cerium species and revealed an improvement in surface area, porosity, and active site distribution. Among the synthesized catalysts, the one with 10 wt% Ce exhibited superior catalytic performance, achieving a Fatty Acid Methyl Esters (FAME) content of 85.71 wt% after 6 h of reaction at 240 °C in the esterification of oleic acid. The catalyst also demonstrated good structural stability and reusability over four reaction cycles, with minimal loss of activity. These results highlight the potential of agrowaste–derived materials for developing low–cost and efficient, and reusable acid heterogeneous catalysts, with relevance for glycerol-free FAME production and future biodiesel-related applications.</p>\u0000 </div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12155-026-10970-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Life Cycle Assessment of Biochar: A Bibliometric Analysis of Trends and Future Perspectives","authors":"Betelhem Fetene Admas,&nbsp;Lívia Christina de Araújo Silva Moura,&nbsp;Temesgen Gashaw Tarkegn,&nbsp;Daniel Valadão Silva,&nbsp;Rafael Leandro Fernandes Melo,&nbsp;Frederico Ribeiro do Carmo","doi":"10.1007/s12155-026-10959-8","DOIUrl":"10.1007/s12155-026-10959-8","url":null,"abstract":"<div>\u0000 \u0000 <p>Life Cycle Assessment (LCA) is a vital tool for assessing the environmental impact of biochar throughout its entire life. This study presents a comprehensive bibliometric analysis of global researches on the LCA of biochar conducted between 2015 and 2025, based on 512 publications retrieved from the Web of Science Core Collection. Bibliometric analysis tools, including VOSviewer and Bibliometrix, were applied to map patterns of scientific collaboration, authorship, institutional contributions, and global thematic trends. Results show a consistent growth in scientific output, with the number of articles published in the Journal of Cleaner Production (72), Science of the Total Environment (29), and Renewable &amp; Sustainable Energy Reviews (23). China, the USA, and India are the leading countries in publication number of 493,197 and 149 articles, respectively. Among authors Siming You, Yong Sik Ok, and Wei-Hsin Chen demonstrate strong scientific influence with publication number of 17, 14, and 12, respectively. Keyword and thematic analyses reveal a clear transition from early studies primarily focused on biochar soil amendment toward more advanced themes, including carbon sequestration, carbon footprint, and climate change mitigation. Despite various system boundaries, and impact categories within LCA studies, biochar shows the carbon negativity impact especially in the soil application. The integration of LCA with techno-economic analysis (TEA) is the emerging area that estimates full environmental and economic benefit of waste valorization and carbon credit value of biochar. Overall, this review identifies major research hotspots and emerging trends, offering a comprehensive knowledge map for future researchers in the field.</p>\u0000 </div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147362842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal Liquefaction: Advancing Biomass Conversion for Sustainable Biofuel Production","authors":"Santhosh Kumar Murugesan,&nbsp;Mohan Cigurupadi Ganesan","doi":"10.1007/s12155-026-10968-7","DOIUrl":"10.1007/s12155-026-10968-7","url":null,"abstract":"<p>The fast demise of fossil fuels and increasing adverse environmental impacts resulting from their utilization has intensified the demand for renewable and sustainable energy sources. Hydrothermal liquefaction (HTL) has emerged as a promising thermochemical process for converting wet biomass into high quality bio-oil, offering a sustainable pathway for renewable energy production. This review provides a comprehensive analysis of diverse feedstocks utilized in HTL, highlighting their unique characteristics and implications on bio-oil yield and quality. The operating parameters, such as temperature, pressure, residence time, and biomass to solvent ratio, are discussed in detail, emphasizing their critical role in optimizing the process efficiency and product properties. It highlights the critical role of catalysts, such as metal-based and zeolite catalysts, in enhancing biomass transformation through reactions like deoxygenation, hydrogenation, and cracking. Additionally, this review explores various reactor configurations and novel designs, outlining their distinct advantages based on feedstock properties and operational requirements. Strategies for upgrading and synthesizing advanced bio-oil, such as fast HTL, hydrotreating and co-processing, are discussed as essential steps toward producing drop-in fuels compatible with existing energy infrastructure. This review underscores the advancements and future potential of HTL technology as a cornerstone for sustainable biofuel production and a circular bioeconomy.</p><p>• HTL diverse feedstocks and operating parameters for producing bio-oil are discussed</p><p>• Emphasized the influence of catalysts on biomass transformation</p><p>• Various reactor types provide unique advantages based on feedstock and operation</p><p>• The quality of HTL bio-oil and future synthesis/upgrading</p>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147363143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Economic Potential of Producing Bioethanol From Sweet Potatoes for Tropical Regions","authors":"Chathushka Jayawardena,&nbsp;Chandima Gomes","doi":"10.1007/s12155-026-10972-x","DOIUrl":"10.1007/s12155-026-10972-x","url":null,"abstract":"<div>\u0000 \u0000 <p>This review presents a comprehensive techno-economic evaluation of producing bioethanol from sweet potatoes (<i>Ipomoea batatas</i> (L.) Lam.) in tropical regions, highlighting its agronomic, economic, environmental, and policy implications, and introducing a novel dual-role perspective that examines sweet potato simultaneously as a food and fuel crop. Sweet potato, a high-starch, drought-tolerant crop, demonstrates remarkable adaptability to low-input farming and marginal lands, traits which render it a compelling bioethanol feedstock for tropical countries grappling with food-energy nexus challenges. Drawing on a systematic qualitative literature review, the study quantifies potential ethanol yields of 4,500–10,000 L/ha/year under dual-cropping systems, benchmarked against maize, cassava, and sugarcane. A techno-economic model estimates capital expenditures, operating costs, and revenue streams, incorporating co-products like animal feed and CO₂. Financial indicators, including Levelized Cost of Ethanol ($0.50–$0.75/L), IRR (12–25%), and payback periods (3–6 years), are analysed under yield, cost, and market volatility scenarios. The study further examines GHG reduction potential (40–60% vs. gasoline), efficient land/water use, and strategies to mitigate food-vs-fuel trade-offs through marginal land use and dual-purpose cropping. Social dimensions such as rural employment and gender inclusivity are explored, especially given women’s predominant role in sweet potato cultivation. Policy and market drivers, biofuel mandates, PPPs, and regional trade are evaluated for their enabling roles. The findings advocate for the integration of sweet potato into national bioenergy portfolios as a viable pathway toward SDG-aligned climate mitigation, rural development, and energy security in tropical economies. This research closes a critical knowledge gap and positions sweet potato as a sustainable, underutilised asset in the future of biofuels.</p>\u0000 </div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s12155-026-10972-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147363127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliable Model Development of Density for Pure Biofuels via Data Driven Approaches","authors":"Mahran Al-Zyoud,&nbsp;Magdi E. A. Zaki,&nbsp;Raed Alfilh,&nbsp;Gadug Sudhamsu,&nbsp;Prabhat Kumar Sahu,&nbsp;Murari Devakannan Kamalesh,&nbsp;Sumit Sharma,&nbsp;Sobhi M. Gomha,&nbsp;Nargis Yousafzai","doi":"10.1007/s12155-026-10984-7","DOIUrl":"10.1007/s12155-026-10984-7","url":null,"abstract":"<div><p>Fatty acid methyl esters (FAMEs) are extensively utilized as pure biofuels due to their renewable origin, biodegradability, and favorable environmental performance. In this study, a wide range of machine learning techniques including Decision Trees, Lasso Regression, AdaBoost, Ensemble Learning, k-Nearest Neighbors (KNN), Convolutional Neural Networks (CNN), Multilayer Perceptron Artificial Neural Networks (MLP-ANN), Random Forest, and Support Vector Regression (SVR) were employed to develop accurate predictive models for FAME density. The models were trained using a comprehensive dataset comprising 2924 experimental density measurements collected from the literature, covering wide ranges of temperature, pressure, molecular weight, and elemental composition. Model performance was rigorously evaluated using statistical metrics such as the coefficient of determination (R²), mean squared error (MSE), and absolute average relative error (AARE%). Among the investigated approaches, the Ensemble Learning model achieved the highest predictive accuracy, yielding an R² of 0.982, a low MSE of 27.75, and an AARE% below 0.14%. Sensitivity analysis and SHAP (SHapley Additive exPlanations) evaluation consistently identified temperature as the dominant factor influencing FAME density, followed by pressure, while molecular weight and elemental composition exhibited comparatively weaker effects. The reliability of the dataset was further confirmed through leverage-based outlier detection. Overall, the proposed data-driven framework provides a cost-effective and reliable alternative to experimental density measurements, enabling accurate density estimation of FAME-based biofuels over broad operating conditions.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147363221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Waste Gasification for Hydrogen Production: Regional Challenges, Sustainability Pathways, and Future Research Directions","authors":"Eduardo Sánchez-Ramírez,&nbsp;Maricruz Juarez-García,&nbsp;Brenda Huerta-Rosas,&nbsp;Jesús Núñez-López,&nbsp;Martha Patricia Calderón-Alvarado,&nbsp;Juan Gabriel Segovia-Hernández","doi":"10.1007/s12155-026-10971-y","DOIUrl":"10.1007/s12155-026-10971-y","url":null,"abstract":"<div><p>Waste gasification is a promising route for sustainable hydrogen production, yet its deployment remains highly uneven across regions. This review critically analyzes the technological, economic, environmental, and socio-political constraints governing waste gasification in industrialized and emerging economies, with particular emphasis on feedstock heterogeneity, cost competitiveness, and governance challenges. Key research gaps are identified, including the limited availability of experimental studies on unsegregated wastes, the underutilization of process intensification strategies such as high-gravity and membrane-assisted gasifiers, and the lack of integrated environmental and social life cycle assessments under real-world conditions. Based on these insights, a regionalized deployment roadmap is proposed, distinguishing large-scale gasification systems with integrated CO₂ capture in China, the United States, and Europe from decentralized, modular, and digitally assisted configurations tailored to Latin America and Africa. Sustainability benefits differ markedly by region, with emission reduction and circularity gains in industrialized economies and improvements in energy access, waste management, and social inclusion in emerging regions. Pilot-scale evidence further indicates that biomass–plastic co-gasification can enhance hydrogen yields by up to 90–110% under optimized conditions.</p></div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147341130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advancing Sorghum-Based Bioethanol for the Energy Transition Program in Indonesia: Economic and Environmental Aspects","authors":"Soni Solistia Wirawan,&nbsp;Agus Sugiyono,&nbsp;Ni Putu Dian Nitamiwati,&nbsp;Palupi Tri Widiyanti,&nbsp;Romelan Romelan,&nbsp;Yayan Heryana,&nbsp;Ana Nurhasanah,&nbsp;Ibrahim Ahmad Ibadurrohman,&nbsp;Fadhlullah Ramadhani,&nbsp;Mokhtar Mokhtar,&nbsp;Andrias Rahman Wimada,&nbsp;Maharani Dewi Solikhah","doi":"10.1007/s12155-026-10960-1","DOIUrl":"10.1007/s12155-026-10960-1","url":null,"abstract":"<div>\u0000 \u0000 <p>Sorghum presents promising prospects as an alternative feedstock for bioethanol production, owing to its high sugar content and superior agronomic properties. This study examines the feasibility of sorghum-based bioethanol in supporting the national energy mix target and reducing greenhouse gas emissions. The distribution of areas across 38 provinces in Indonesia related to potential sorghum cultivation was identified using a remote sensing approach, differentiated into four suitability classifications to estimate bioethanol production capacity. The concept of an integrated sorghum processing plant with a capacity of 4 kL per day is adopted, requiring 300 ha of land for cultivation for each bioethanol plant. The results of the study indicate that utilizing the national sorghum potential can significantly contribute to achieving the national biofuel target and reducing greenhouse gas emissions. This study identified 3.334 million ha of land in Indonesia suitable for sorghum cultivation, with a bioethanol production potential of 13.31 million kL per year, equivalent to 36.95% of the national gasoline demand in 2023, the base year of this study. Under the proposed sorghum bioethanol scenario, this alternative fuel could reduce greenhouse gas emissions by up to 25.8 million tons of CO₂eq by 2045 compared to the business-as-usual scenario. The implementation of sorghum-based bioethanol aligns with the national emission reduction program aimed at achieving the net-zero emissions target by 2060. Thus, sorghum can be one of the solutions to support the national energy and environmental targets. This study provides an important foundation for the development of sorghum-based bioethanol in Indonesia.</p>\u0000 </div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147341206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Briquetting Conditions for Groundnut Shells and Maize Stalks Using Response Surface Methodology","authors":"Jimmy Eling,&nbsp;Emmanuel Menya,&nbsp;Michael Robson Atim,&nbsp;David Kilama Okot","doi":"10.1007/s12155-026-10961-0","DOIUrl":"10.1007/s12155-026-10961-0","url":null,"abstract":"<div>\u0000 \u0000 <p>The quality attributes of briquettes depend on feedstock characteristics and process conditions. This study aimed at optimizing compressive strength and specific energy requirement using Response Surface Methodology (RSM). An RSM based on Central Composite Design (CCD), comprising four factorial, four axial, and six center points, was used to generate different sets of experimental conditions. Each condition was replicated three times, yielding a total of 42 experimental runs. Briquetting temperature (40–110 °C) and compression pressure (34–204 MPa) were treated as independent variables in the response modeling. The model terms included constant, linear, interaction, and quadratic components. The optimum briquetting temperature and pressure were 110 °C and 123 MPa for raw groundnut shells and 97 °C and 108 MPa for raw maize stalks. The corresponding optimum specific energy requirement and compressive strength were 22.5 kJ/kg and 21.4 MPa for groundnut shells, and 11.0 kJ/kg and 42.4 MPa for maize stalks. Torrefaction increased the specific energy requirement for briquetting by 42.2% for groundnut shells and 31.8% for maize stalks. Conversely, torrefaction reduced the compressive strength by 74.8% for groundnut shell briquettes and 18.6% for maize stalk briquettes.</p>\u0000 </div>","PeriodicalId":487,"journal":{"name":"BioEnergy Research","volume":"19 1","pages":""},"PeriodicalIF":3.0,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147340116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}