Xiaoxiao Yin , Junyu Tao , Jinglan Wang , Beibei Yan , Guanyi Chen , Zhanjun Cheng
{"title":"Prediction of activation energy of lignocellulosic biomass pyrolysis through thermogravimetry-assisted machine learning","authors":"Xiaoxiao Yin , Junyu Tao , Jinglan Wang , Beibei Yan , Guanyi Chen , Zhanjun Cheng","doi":"10.1016/j.biombioe.2025.107644","DOIUrl":"10.1016/j.biombioe.2025.107644","url":null,"abstract":"<div><div>Activation energy is a crucial indicator to explain the pyrolysis process of lignocellulosic biomass that can be converted into clean fuels and high-value-added chemicals. The present work employs machine learning algorithms to explore the hidden correlations between feedstock characteristics, thermogravimetry performance, reaction kinetic equation, and activation energy, which allows these kinetic parameters to be obtained without the Arrhenius equation. Bayesian optimization improves the Gradient boosting decision tree model performance: MSE of 198.67, <em>R</em><sup>2</sup> of 0.991. Feature importance analysis and partial dependence analysis show that feedstocks with high lignin content and low nitrogen and oxygen content usually have higher activation energy. Meanwhile, the temperature when the mass is reduced to 80% of the initial mass during the thermogravimetry process plays a very important role in activation energy. The results show that the machine learning model can accurately learn the relationship between thermogravimetry curve characteristics and activation energy, so it can accurately predict the activation energy of lignocellulosic biomass pyrolysis. This approach can potentially save time and effort that would otherwise be spent on tedious calculations required by kinetic reaction equations. Additionally, it can provide useful guidance for experimental studies.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"194 ","pages":"Article 107644"},"PeriodicalIF":5.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sustainable valorization of jojoba oilcake: Pressing method-dependent protein stability and functionality for food applications","authors":"Nevetha Ravindran, Sushil Kumar Singh, Poonam Singha","doi":"10.1016/j.biombioe.2025.107660","DOIUrl":"10.1016/j.biombioe.2025.107660","url":null,"abstract":"<div><div>Jojoba (<em>Simmondsia chinensis</em>) is known for its highly versatile oil, which has good therapeutic and cosmetic applications. The residual meal, rich in protein (26–29 %), is unexploited and limited for use in food systems due to the presence of anti-nutritional factors (mainly in the seed coat). This study attempts to upcycle jojoba oil cake to produce alternative proteins by investigating its extractability, and physicochemical, and functional characteristics. Three different extraction methods, namely, hot-pressed, dehulled and hot-pressed, and cold-pressed, were adopted. The results showed a significant impact of the pressing techniques on the properties of jojoba protein. Dehulling resulted in high purity (81.34 %) proteins with enhanced nutritional profile but had a negative effect on the stability (T<sub>d</sub>: 76.9 °C) and functional properties. Hot pressing methods resulted in protein dissociation, denaturation (T<sub>d</sub>: 79.9 °C), and disintegration, leading to the loss of structural integrity, which was evident from the SEM images. Conversely, the cold-pressed proteins exhibited high thermal stability (T<sub>d</sub>: 87.4 °C), bioactivity (73.63 % DPPH free radical scavenging activity), and functional properties despite having comparatively lower purity (61.53 %). The supremacy is attributable to the structural integrity of the proteins, which is preserved due to minimal processing impact. Overall, the findings demonstrated that jojoba proteins derived from cold-pressed oil cake displayed remarkable functional properties, suggesting their potential as a valuable functional ingredient. This enhances the circular bioeconomy through the use of agro-industrial residues in the food industry, resulting in waste reduction and promoting sustainability.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"194 ","pages":"Article 107660"},"PeriodicalIF":5.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marta Navarro , Óscar de la Iglesia , Carlos Téllez , Joaquín Coronas
{"title":"Influence of the delamination of zeolitic imidazolate framework ZIF-7-III on the conversion of sucrose into methyl lactate","authors":"Marta Navarro , Óscar de la Iglesia , Carlos Téllez , Joaquín Coronas","doi":"10.1016/j.biombioe.2025.107662","DOIUrl":"10.1016/j.biombioe.2025.107662","url":null,"abstract":"<div><div>The catalytic conversion of sugars to methyl lactate has been in the spotlight of the scientific community in the last decades. In this context, delaminated materials can provide better catalytic performances than their precursors, since they have a better accessibility to their active sites. In order to improve the yield to methyl lactate (ML), new delaminated material ZIF-7-III_EX was synthesized from the exfoliation of the dense Zn-based zeolitic imidazolate framework ZIF-7-III. Different techniques, namely XRD, SEM, TEM, thermogravimetric analysis and CO<sub>2</sub> adsorption, were carried out to characterize the obtained materials as well as to verify the exfoliation of the precursor. Regarding the catalytic results, as-synthesized ZIF-7 showed a promising yield to ML, 41.2 %, superior to that achieved by ZIF-9 (based on Co instead of Zn). In addition, the delaminated material ZIF-7-III_EX reached a ML yield of 69.1 %, which implies 67.7 % and 97.4 % of improvements with respect to ZIF-7 and to ZIF-7-III, respectively. The reuse of some selected catalyst materials derived from ZIF-7-III was also studied.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"194 ","pages":"Article 107662"},"PeriodicalIF":5.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143177183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Utilizing luffa sponge-derived porous activated carbon as a sustainable environmental bio-mass for renewable energy storage applications","authors":"Brundha Chidambaram , Prabhu Sengodan , Seokwoo Jeon , Werayut Srituravanich","doi":"10.1016/j.biombioe.2025.107667","DOIUrl":"10.1016/j.biombioe.2025.107667","url":null,"abstract":"<div><div>The advancement of sustainable technologies for producing green energy sources is essential, especially for energy storage and conversion methods that preserve ecosystems. A promising approach involves using low-cost, eco-friendly activated carbon derived from bio-waste materials, such as luffa sponge, for energy storage applications. This study details the preparation of activated carbon (LSAC) derived from luffa sponge through hydrothermal treatment followed by KOH activation at 400 °C, 600 °C, and 800 °C to optimize its properties. The biomass-derived carbon structural and morphological properties are analyzed, and these materials are used as electrodes to assess their electrochemical characteristics. According to cyclic voltammetry tests, LSAC-8 demonstrates a specific capacitance of 411.63 F g⁻<sup>1</sup> at a current density of 1 A g⁻<sup>1</sup>, exhibiting much lower electrochemical impedance than the other samples. LSAC-8 also demonstrates low internal resistance (1.25 Ω) and superb cycling stability over 2000 cycles, enhancing the electrochemical performance of biomass resources. Delivering a high energy density of 24.88 Wh kg<sup>−1</sup> at a power density of 1230 W kg<sup>−1</sup> in a PVA/KOH electrolyte, the LSAC-8-based symmetric supercapacitor demonstrates substantial commercial potential for high-efficiency supercapacitor technologies.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"194 ","pages":"Article 107667"},"PeriodicalIF":5.8,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Catalytic hydrothermal liquefaction of wheat straw and chemical profiling of bio-crude oil","authors":"Falguni Pattnaik , Kshanaprava Dhalsamant , Sonil Nanda , Ajay K. Dalai","doi":"10.1016/j.biombioe.2025.107643","DOIUrl":"10.1016/j.biombioe.2025.107643","url":null,"abstract":"<div><div>In this study, a central composite design model was generated under response surface methodologies for the hydrothermal liquefaction of the wheat straw by considering the different process variables such as temperature (270–330 °C), reaction time (20–60 min) and feed concentration (5–15 wt%) to optimize the bio-crude oil yield and generate an experimental model. Moreover, at the optimized conditions, different catalysts such as K<sub>2</sub>CO<sub>3</sub>, Fe, ZrO<sub>2</sub>, Fe-K<sub>2</sub>CO<sub>3</sub> and ZrO<sub>2</sub>-K<sub>2</sub>CO<sub>3</sub> were employed for the hydrothermal liquefaction of wheat straw to maximize the bio-crude oil yield and decrease the oxygen content. Among all catalysts, Fe-K<sub>2</sub>CO<sub>3</sub> delivered the highest bio-crude oil yield of 29 wt% with the lowest oxygen content of 14 wt%. The chromatographic analysis established molecular profiling of bio-crude oil samples, which revealed the presence of different phenolic compounds like phenol, 2-methoxy phenol and catechol including other components such as aldehydes, cyclic ketones, octene, hexadecane and octadecane. Spectroscopic and compositional profiling of bio-crude oil revealed different organic functional groups and aromatic compounds essential for the generation of molecular-level reaction mechanisms and subsequent upgrading of bio-crude oil for transportation fuel and various chemicals.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"194 ","pages":"Article 107643"},"PeriodicalIF":5.8,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143174998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Production of hydrogen-rich syngas from catalytic reforming of biomass gasification tar model compounds coupled with in-situ CO2 capture","authors":"Cui Quan, Shaoxuan Feng, Ningbo Gao","doi":"10.1016/j.biombioe.2024.107569","DOIUrl":"10.1016/j.biombioe.2024.107569","url":null,"abstract":"<div><div>Biomass gasification for hydrogen production has received widespread attention in recent years as a sustainable energy technology. However, the biomass gasification process produces tar. This can seriously affect subsequent gas cleaning and utilization. In this study, toluene was used as a tar model compound. The effects of different catalyst carriers, reforming temperatures, S/C ratio, and <em>in-situ</em> CO<sub>2</sub> capture on the yield of toluene steam reforming were investigated. The results showed that under the same working conditions, the hydrogen yield of the SiC carrier catalyst was much higher than that of the SiO<sub>2</sub> and Al<sub>2</sub>O<sub>3</sub> carriers. This is due to the excellent thermal conductivity and suitable acid-base properties of the SiC carrier. CaO could effectively adsorb CO₂ and increase the hydrogen yield. The hydrogen yield reached 90.63 % with the addition of 0.3 g of CaO, which was 13.7 % higher than that without the addition of CaO. In addition, to investigate the structural changes and chemical state of the catalysts, the differences between the catalysts before and after use were analyzed using a variety of characterization methods. This study provides critical insights into the design of efficient catalysts and processes for overcoming the challenges associated with biomass-derived tar.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"193 ","pages":"Article 107569"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142886924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Use of methanol as a promoter for ammonia combustion","authors":"A. Ruiz-Gutiérrez, I. De Diego, M.U. Alzueta","doi":"10.1016/j.biombioe.2024.107572","DOIUrl":"10.1016/j.biombioe.2024.107572","url":null,"abstract":"<div><div>This work aims to study the oxidation of ammonia and methanol mixtures (NH<sub>3</sub>/CH<sub>3</sub>OH). For this purpose, laboratory experiments were conducted using a quartz flow reactor at atmospheric pressure, in a temperature range of 875–1425 K. The oxygen excess ratio (λ) and the NH<sub>3</sub>/CH<sub>3</sub>OH ratio were modified during the experiments. The experimental results have been simulated with a literature-based kinetic mechanism. The results show that the presence of CH<sub>3</sub>OH and the oxygen excess ratio affect the conversion of NH<sub>3</sub>, shifting its oxidation to lower temperatures as these variables increase. The oxidation of both fuels was slightly boosted with increasing CH<sub>3</sub>OH concentration. The λ study showed that the fuel-lean conditions accelerate NH<sub>3</sub> oxidation at lower temperatures whereas do not have the same effect on CH<sub>3</sub>OH oxidation. The H radical concentration significantly influences fuel consumption, especially in reactions involving CH<sub>3</sub>OH and NH<sub>2</sub>, and it is also key for inhibition processes. CH<sub>3</sub>OH was found to initiate NH<sub>3</sub> reactions, with strong competition for OH radicals between the two fuels. Nevertheless, methanol helps reduce ammonia's oxidation temperature. CH<sub>2</sub>OH was identified as the predominant species following H-abstraction from CH<sub>3</sub>OH. In the NH<sub>3</sub>/CH<sub>3</sub>OH ratio studies, increasing methanol concentration lowered the oxidation temperature of both fuels, with a temperature difference of up to 150 K observed for NH<sub>3</sub>/CH<sub>3</sub>OH ratios from 0.6 to 10. Increasing methanol concentration for a given NH<sub>3</sub> value also shifted the prominence of secondary reaction pathways, further influencing the overall oxidation process.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"193 ","pages":"Article 107572"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142911778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mengtian Huang , Zhuocheng Jin , Hong Ni , Peining Zhang , Huanan Li , Jiashu Liu , Chengcheng Weng , Zhengbing Jiang
{"title":"Secretory expression of xylA under high dissolved oxygen to improve the xylose fermentation efficiency of Saccharomyces cerevisiae","authors":"Mengtian Huang , Zhuocheng Jin , Hong Ni , Peining Zhang , Huanan Li , Jiashu Liu , Chengcheng Weng , Zhengbing Jiang","doi":"10.1016/j.biombioe.2024.107543","DOIUrl":"10.1016/j.biombioe.2024.107543","url":null,"abstract":"<div><div>The isomerization of xylose to xylulose is considered the most promising method for xylose utilization. The xylose isomerase (XI) gene <em>xylA</em> from <em>Orpinomyces</em> sp. ukk1 was expressed intracellularly and extracellularly in modified <em>Saccharomyces cerevisiae</em> strains INV<em>Sc</em>-<em>xylA</em> and INV<em>Sc</em>-SS-<em>xylA</em>, respectively, to enhance the synthesis of bioethanol, which is frequently utilized as a substitute for conventional fossil fuels. Moreover, the xylose transporter gene <em>Xltr1p</em> from <em>Trichoderma reesei</em> was co-expressed with <em>xylA</em> expressed intracellularly for INV<em>Sc</em>-<em>xylA</em>-<em>Xltr1p</em> to further improve xylose utilization in glucose and xylose co-fermentation. INV<em>Sc</em>-SS-<em>xylA</em> in mixed sugars consumed 8.30 g/L xylose, which was approximately 3- and 2-fold higher than these of INV<em>Sc</em>-<em>xylA</em> and INV<em>Sc</em>-<em>xylA</em>-<em>Xltr1p</em>, respectively. This result indicated converting xylose to xylulose prior to absorption was more effective for xylose consumption of <em>S. cerevisiae</em>. Furthermore, high dissolved oxygen (DO) promoted xylose utilization, regardless <em>xylA</em> was expressed extracellularly or intracellularly. INV<em>Sc</em>-SS-<em>xylA</em> had a 1.5-fold higher xylose consumption rate than INV<em>Sc</em>-<em>xylA</em>-<em>Xltr1p</em>. Transcriptome analysis of INV<em>Sc</em>-SS-<em>xylA</em> under different DO levels indicated 967 differentially expressed genes (DEGs) were upregulated and 796 DEGs were downregulated. Most upregulated DEGs were related to TCA cycle, amino acid metabolism and energy metabolism, etc. INV<em>Sc</em>-SS-<em>xylA</em> contributed to sugar-to-ethanol yield reached 0.25 g/g from pretreated bagasse hydrolysates, without detoxifying or washing pretreated biomass. These results demonstrated xylose metabolism can be improved by <em>xylA</em> expressed extracellularly in high DO production of ethanol from mixed sugars and provide useful methodological guidance in industrial ethanol production using undetoxified biomass.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"193 ","pages":"Article 107543"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fidel A. Aguilar-Aguilar , Violeta Y. Mena-Cervantes , Cesar Romero-Hernández , Fabián S. Mederos-Nieto , Alejandro Ramírez- Estada , Raúl Hernández-Altamirano
{"title":"Thermal, structural, and compositional evaluation of coyol shell pretreatments for enhanced lignocellulosic biomass utilization","authors":"Fidel A. Aguilar-Aguilar , Violeta Y. Mena-Cervantes , Cesar Romero-Hernández , Fabián S. Mederos-Nieto , Alejandro Ramírez- Estada , Raúl Hernández-Altamirano","doi":"10.1016/j.biombioe.2024.107518","DOIUrl":"10.1016/j.biombioe.2024.107518","url":null,"abstract":"<div><div>The valorization of coyol shell (<em>Acrocomia aculeata</em>) lignocellulose presents significant potential for biofuel and bioproduct production yet remains underexplored. This study assessed the impact of three pretreatment methods—NaOH, NaOH/Na₂S, and EtOH—on the structural, thermal, and chemical properties of the coyol shell to enhance its utilization in biorefinery processes. Using advanced characterization techniques such as Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), elemental analysis, and scanning electron microscopy (SEM), this research provides a detailed comparative analysis of pretreatment methods on this underutilized biomass. FTIR results revealed significant reductions in hydroxyl (3300 cm⁻<sup>1</sup>) and carbonyl (1735 cm⁻<sup>1</sup>) groups, with EtOH showing the most effective hemicellulose and lignin degradation. TGA analysis indicated an increase in volatile matter content after pretreatments, with EtOH retaining 95.16 %, NaOH 96.09 %, and NaOH/Na₂S 95.97 %, compared to 73.97 % in untreated biomass. Elemental analysis showed an increase in carbon content (C) and a decrease in oxygen-to-carbon (O/C) ratio across all pretreatments, highlighting improved energy density and suitability for biofuel production. SEM analysis confirmed structural disruption, with NaOH/Na₂S yielding the most fragmented and porous morphology, facilitating further biomass processing. The theoretical biochemical methane potential (BMP) demonstrated that NaOH achieved 396 mL CH₄/g VS, significantly higher than untreated biomass at 327 mL CH₄/g VS. This indicates the enhanced accessibility of fermentable components, making pretreated biomass suitable for biogas production. The results establish a foundation for optimizing pretreatment strategies to enhance the valorization of coyol shell in sustainable biorefinery frameworks, contributing to a circular bioeconomy.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"193 ","pages":"Article 107518"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaowei Jin , Wenbin Guo , Tianyu Shi , Jian Yang , Fan Hu , Zhipeng Wang
{"title":"Research on characterization of pellet characteristics of straw and potato residue mixture based on deep learning","authors":"Xiaowei Jin , Wenbin Guo , Tianyu Shi , Jian Yang , Fan Hu , Zhipeng Wang","doi":"10.1016/j.biombioe.2024.107551","DOIUrl":"10.1016/j.biombioe.2024.107551","url":null,"abstract":"<div><div>Compressing straw and potato residues into pellets addresses transportation and storage challenges while promoting sustainable waste management. In this study, a deep learning model was utilized to ascertain the parameters within the microscopic images of the mixed pellets. Moreover, the mechanisms of changes in the molding process of the mixed pellets were analyzed in conjunction with their mechanical properties. Firstly, a cylindrical specimen compressed by an electronic universal testing machine was employed to ascertain mechanical indices, including the relaxation ratio and crushing strength. The ResNet-Unet model was used to identify changes in parameters, such as the presence of solid bridges and cracks, in microscopic images under varying experimental conditions. The findings of the study demonstrate that the model exhibits an accuracy of 92 % and 94 % in identifying solid bridges and cracks, respectively. Secondly, the mechanisms behind the changes in relaxation ratio and crushing strength were subjected to in-depth analysis based on the microscopic images observed by scanning electron microscopy (SEM) under different experimental conditions. The study revealed that the formation of solid bridges during the production of biomass pellets is a dynamic process involving growth, diffusion, and merging with other solid bridges. Additionally, the formation of solid bridges can influence the changes in relaxation ratios and crushing strengths. Meanwhile, the generation of solid bridges was not found to be affected by the feeding amount. It was observed that an appropriate feeding amount could reduce the length of cracks on the pellet surface and improve the quality of the molding.</div></div>","PeriodicalId":253,"journal":{"name":"Biomass & Bioenergy","volume":"193 ","pages":"Article 107551"},"PeriodicalIF":5.8,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142887052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}