Journal of Analytical and Applied Pyrolysis最新文献

{"title":"The effect of different reservoir minerals on in-situ hydrothermal upgrading of heavy oil in simulated stratigraphic environment","authors":"Jingjing Li,&nbsp;Chenglong Cao,&nbsp;Zhi Yang,&nbsp;Guizhong Deng,&nbsp;Dayong Qing,&nbsp;Xiaodong Tang","doi":"10.1016/j.jaap.2025.107314","DOIUrl":"10.1016/j.jaap.2025.107314","url":null,"abstract":"<div><div>In-situ hydrothermal upgrading of heavy oil using nanocatalysts in reservoirs represents a promising future technology for enhanced oil recovery. However, the influence of reservoir minerals on upgrading products remains unclear. This study employed a physical simulation apparatus to investigate the effects of three layered silicate clay minerals (clay, montmorillonite, illite) on hydrothermal upgrading under reservoir conditions with permeability of 2000 (±100) mD, porosity of 25 %, reaction temperature of 240°C, 0.1 wt% nano-Fe₂O₃ catalyst, oil-water ratio of 1:1, and 24-hour duration. Experimental results demonstrate that layered silicate minerals synergistically enhanced the catalytic performance of nano-Fe₂O₃ for heavy oil upgrading. Clay exhibited the most significant upgrading effect, achieving 10.31 % reduction in heavy components with 3.92 % decrease in asphaltene content, followed by montmorillonite (9.69 %) and illite (9.28 %). Mechanistic analysis reveals that clay minerals functioned as effective supports for Fe₂O₃ nanoparticles, preventing aggregation and maintaining catalytic stability. Furthermore, interlayer-adsorbed water molecules decomposed under high temperature to generate active hydrogen species (H⁺), while iron oxide facilitated hydrogen release through Fe²⁺/Fe³ ⁺ redox cycling. These synergistic effects collectively promoted hydrocracking of heavy oil macromolecules and heteroatom (S, N, O) removal. This study elucidates the critical role of layered silicate minerals in nanocatalyst-assisted in-situ heavy oil upgrading, providing theoretical support for improving oil quality and recovery efficiency through mineral-catalyst synergies.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107314"},"PeriodicalIF":6.2,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ca-catalysis mechanisms from coal pyrolysis to high energy density fuel precursors: Multiscale insights via ReaxFF MD and experiment","authors":"Bopan Wang ,&nbsp;Lihong Wei ,&nbsp;Yanan Li ,&nbsp;Tianhua Yang ,&nbsp;Yanlong Li ,&nbsp;Qiang Gan","doi":"10.1016/j.jaap.2025.107305","DOIUrl":"10.1016/j.jaap.2025.107305","url":null,"abstract":"<div><div>The development of coal-based high-energy-density (HED) aviation fuels is critical for advancing diversified energy strategies in the aviation industry. A core scientific challenge lies in the directional regulation of naphthalene (a key HED precursor) generation during coal pyrolysis. This study integrates experimental methods with Reactive Force Field molecular dynamics (ReaxFF MD) simulations, revealing for the first time the detailed reaction pathway of naphthalene formation and the calcium catalytic enhancement mechanism. By tracking carbon skeleton evolution, we construct a quantitative reaction network for naphthalene generation and identified eight distinct pathways, including a previously unreported route involving the cleavage–recombination of monocyclic aromatic C₁₃H₁₈. Experimental results demonstrate that the introduction of calcium significantly accelerates the macromolecular cracking rate, with an increase of up to 75 %; by catalyzing new pathways and promoting naphthol dehydroxylation, the yield of naphthalene derivatives is effectively increased by 56 % under experimental conditions. This study offers critical theoretical guidance and technical support for optimizing coal-based HED fuel precursor production and designing efficient calcium-based catalysts.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107305"},"PeriodicalIF":6.2,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comprehensive insights into polycarbonate (PC) pyrolysis mechanisms: Reaction pathways and formation processes of phenolics, gases, dibenzofuran, xanthone","authors":"Liming Tai ,&nbsp;Yang Long ,&nbsp;Shi Yan ,&nbsp;Yan Zhu ,&nbsp;Jinbao Huang ,&nbsp;Hong Wang ,&nbsp;Jiankai Ou ,&nbsp;Wenjing Duan","doi":"10.1016/j.jaap.2025.107313","DOIUrl":"10.1016/j.jaap.2025.107313","url":null,"abstract":"<div><div>In order to deeply explore the pyrolysis mechanism of polycarbonate (PC) and the evolution of products, in this paper, carbonate dimer was used as a model compound of PC and its degradation processes were comprehensively studied through quantum chemical calculations. The calculations results show that in the initial stage of degradation, the end-carboxyl group of PC is most susceptible to decarboxylation via concerted reaction with an energy barrier of 155.5 kJ/mol, followed by the scission of the C-CH₃ bond of the alkane chain and the C-O bond of the carbonate group, with bond dissociation energies of 301.5 and 344.5 kJ/mol. The involvement of H radical significantly promotes the reactivity in bimolecular reaction system, and the energy required to scission the C-CH₃ bond and the C-O bond was reduced to 121.7 and 153.3 kJ/mol, respectively. The addition of H radicals on the benzene ring observably reduces the activation energy for bridge bond breaking, with energy barriers of 36.1 and 39.0 kJ/mol. The final degradation products mainly include a variety of phenolic compounds (e.g., phenol, bisphenol A, etc.), and gaseous products such as CO₂ and CO. CO₂ is mainly generated through concerted decarboxylation reaction, while CO is formed by the decarbonylation reaction of the radical IM14. The formation of dibenzofuran is mainly achieved through the reaction of H radicals or CH₃ radicals with diphenyl ether, and the evolutionary mechanism of xanthone is proposed.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107313"},"PeriodicalIF":6.2,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"End-group analysis of polycarbonates using evolved gas analysis-time-of-flight mass spectrometry combining principal component analysis and Kendrick mass defect analysis","authors":"Sayaka Nakamura ,&nbsp;Hiroaki Sato ,&nbsp;Takato Ishida ,&nbsp;Hideaki Hagihara ,&nbsp;Hideyuki Shinzawa ,&nbsp;Ryota Watanabe","doi":"10.1016/j.jaap.2025.107311","DOIUrl":"10.1016/j.jaap.2025.107311","url":null,"abstract":"<div><div>This paper introduces a novel method that uses evolved gas analysis with time-of-flight mass spectrometry coupled with field ionization (EGA-FI-TOFMS) to analyze the end-group structures of polycarbonate. To validate the analytical method, polycarbonates featuring two different types of end groups—tert-butylphenol and cumyl phenol—were analyzed. A data mining technique combining principal component analysis (PCA) and Kendrick mass defect (KMD) analysis was applied to the temperature-dependent mass spectra obtained from EGA-FI-TOFMS to extract key mass information related to specific evolved products arising from the end-group structures of the polycarbonate samples. The products derived from the polymer ends were selectively detected during the early stages of pyrolysis because the terminus-derived products resulted from a single cleavage of the polymer chain. The newly developed method, which integrates EGA-FI-TOFMS, PCA, and KMD analysis, provides insights into the end-group structures of polymer materials without requiring prior knowledge. This capability is particularly advantageous for analyzing industrial polymer materials, for which such prior knowledge is often unavailable.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107311"},"PeriodicalIF":6.2,"publicationDate":"2025-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144757838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Changes in the free radical concentration and carbon structure of coke during the coal coking process","authors":"Xinni Zhao ,&nbsp;Hanwen Zhu ,&nbsp;Hengguang Xu ,&nbsp;Lu Tian ,&nbsp;Peng Yu ,&nbsp;Joseph Appiah ,&nbsp;Xiuli Xu ,&nbsp;Jinxiao Dou ,&nbsp;Jianglong Yu","doi":"10.1016/j.jaap.2025.107312","DOIUrl":"10.1016/j.jaap.2025.107312","url":null,"abstract":"<div><div>Free radical concentration and gas release significantly influence coal's coking behavior and cross-linking structure, warranting dedicated research.Matou coking coal (MT) and Yanzhou West gas coal (YZX) were selected for the coking experiments using coke ovens in this study. Herein, the changes in free radical concentration and contents of gas components in the colloidal layers of the MT and YZX coals were analyzed by gas chromatography (GC) and electron spin magnetic resonance spectroscopy (ESR). Results showed that in the formation of the colloidal layer, the cleavage of fatty side chains and oxygen-containing functional groups produces CH₄ and CO₂. When entering the later stage of the formation of the colloidal layer, the active sites on the aromatic clusters begin to bind to each other and amorphous carbon participates in the polycondensation reaction, producing a large amount of H₂. Some of the pyrolysis products undergo secondary pyrolysis reactions,while some aliphatic strutures containing oxygen-containing heterocycles decompose to form CO. The g-value is a characteristic parameter in ESR spectroscopy that measures the interaction between electron spin and the magnetic field, while ΔHₚ₋ₚ represents the peak-to-peak linewidth of the ESR spectrum, serving as an important parameter to measure spectral broadening.The ESR spectrum shows that the stable free radical concentration of coking coal increased in the colloidal layer stage and the condensation and crosslinking reactions between the aromatic structures in the char region exposed the stable free radicals and transformed them into active free radicals. The characteristic parameters (g value and ΔH_p-p) of the ESR spectrum exhibited good regularity in the glial phase, With a correlation between the g value and the full width at half-maximum of the G peak and ΔH_p-p having a good correlation with the relative content of π→π* transitions in the later stage of the glial phase.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107312"},"PeriodicalIF":6.2,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrolysis of different types and sections of end-of-life tyres: Kinetics and experiments to improve product quality","authors":"Alberto Sanchís,&nbsp;María Victoria Navarro,&nbsp;Alberto Veses,&nbsp;Juan Daniel Martínez,&nbsp;María Soledad Callén,&nbsp;José Manuel López,&nbsp;Tomás García,&nbsp;Ramón Murillo","doi":"10.1016/j.jaap.2025.107309","DOIUrl":"10.1016/j.jaap.2025.107309","url":null,"abstract":"<div><div>Pyrolysis contributes to the transition of the tyre industry towards a circular economy model. Tyre rubber is a complex blend of polymers, inorganic additives and grades of carbon black, depending on the tyre type and section. The products of the end-of-life tyres (ELTs) pyrolysis are heavily influenced by the original composition, so separation prior to pyrolysis could be an important step in optimising the recycling process. However, recyclers often ignore the composition of ELTs. This study aims to develop a simple methodology for evaluating the potential resource recovery of ETLs samples from a set of thermogravimetric experiments applying a Distributed Activation Energy Model (DAEM). Pyrolysis experiments were also carried out in a fixed-bed reactor to analyse the composition of the products. Direct linear relations were identified between specific values of the initial mass fraction parameter of the DAEM and the natural and synthetic rubber content, and notably with the limonene content in the pyrolysis oils. A high 12 wt% limonene in the oil product was obtained from the sample with the 83 wt% natural rubber content at 450 ºC. In addition, significant differences in the ash content were observed in the raw recovered carbon black from the tread sections (31 wt%-55 wt%) to the non-tread sections of the ELTs (7 wt%-16 wt%), which had a positive effect on its quality. This work demonstrates that the application of a straightforward methodology on separated types and sections of ELTs can greatly enhance the economic and environmental sustainability of their recycling processes.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107309"},"PeriodicalIF":6.2,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144739411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reaction kinetics and accelerant effects of sulfides in early mature hydrocarbon generation using hydrous pyrolysis","authors":"Tushar Adsul ,&nbsp;Paul C. Hackley ,&nbsp;Javin J. Hatcherian ,&nbsp;Ryan J. McAleer ,&nbsp;Carlin J. Green ,&nbsp;Alan K. Burnham ,&nbsp;Santanu Ghosh ,&nbsp;Josef P. Werne ,&nbsp;Atul Kumar Varma","doi":"10.1016/j.jaap.2025.107307","DOIUrl":"10.1016/j.jaap.2025.107307","url":null,"abstract":"<div><div>Hydrocarbon generation in organic-rich sediments is influenced by the molecular organic composition and relative abundance of associated minerals. Certain mineral-derived elements act as catalysts and reaction intermediaries, facilitating early-stage hydrocarbon formation in potential source rocks. This study investigated the role of sulfur contributed from pyrite as an accelerant in thermal reaction, focusing on its effects on early maturation and consequent hydrocarbon generation from gilsonite (low-sulfur solid petroleum). Hydrous pyrolysis (HP) experiments were conducted on mixtures of gilsonite and pyrite in varying ratios (1:0.1, 1:0.5, 1:1, 1:2, and 1:10 w/w gilsonite:pyrite) at 320, 350, and 370 °C for 72 h. Untreated and thermally altered residues were analyzed using solid bitumen reflectance (BR_o, %), total organic carbon (TOC) content, programmed temperature pyrolysis, scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and X-ray diffraction (XRD) to evaluate the potential accelerant role of pyritic sulfur in hydrocarbon formation. The results show HP residues at 320 and 350 °C with greater pyrite concentrations had higher BR_o, while reflectance values were similar in the 370 °C residues, regardless of pyrite concentration, suggesting enhanced reaction at lower thermal conditions. Increasing pyrite content systematically decreased hydrogen index (HI) values while increasing the transformation ratio (TR) and production index (PI), indicating enhanced conversion of organic matter to hydrocarbons with increasing pyrite concentrations. Gas yields increased with pyrite addition, particularly at 350 °C, confirming secondary cracking effects. However, gas production stabilized or declined at higher pyrite loadings (1:10), suggesting alternative reaction pathways such as coke formation. Our data indicate the presence of pyrite lowers the activation energy for thermal cracking, shifting peak experimental hydrocarbon generation temperatures downward by 20–30 °C, with the most pronounced accelerant effects observed at moderate pyrite concentrations (1:0.5 and 1:1). The thermodynamic framework reveals that pyrite stability is influenced by experimental conditions, with pyrrhotite formation favored in the presence of gilsonite due to reduced oxygen fugacity. Pyrite transformation to pyrrhotite, as observed through XRD, SEM-EDS, and predicted by thermodynamic data, further supports the accelerant role of S, as pyrrhotite exhibits a higher hydrogen transfer potential, promoting early oil generation. These findings highlight the importance of pyrite in modulating hydrocarbon generation pathways in organic-rich systems.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107307"},"PeriodicalIF":6.2,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A dual-stage machine learning framework for comprehensive characterization of waste plastic pyrolysis oils","authors":"Xu Zhang ,&nbsp;Shengji Wu ,&nbsp;Ben Ge ,&nbsp;Qing Zhou ,&nbsp;Bin Yan ,&nbsp;Zezhou Chen","doi":"10.1016/j.jaap.2025.107300","DOIUrl":"10.1016/j.jaap.2025.107300","url":null,"abstract":"<div><div>Pyrolysis is a promising approach to recycling plastic waste by converting it into valuable fuels and chemicals. However, process optimization is hindered by complex interdependencies among critical factors (e.g., plastic composition, pyrolysis temperature, and catalyst acidity) and empirical limitations (e.g., small datasets, nonlinear dependencies, and insufficient mechanistic understanding of composition-specific pathways) in predicting product distributions. To address these challenges, this study proposes a dual-stage machine learning framework for the comprehensive characterization of waste plastic pyrolysis oils, including their yield prediction and detailed compositional analysis. In the first stage, four single models (DT, RF, SVR, and XGB) were employed to predict oil yields, with XGB achieving superior accuracy (<em>R</em>² = 0.959) and SHAP analysis identifying pyrolysis temperature and catalyst acidity as dominant influencing factors. The second stage introduced a stacking-based fusion model to predict detailed oil compositions (alkanes, alkenes, and aromatics), outperforming single models by effectively capturing high-dimensional nonlinearities and feature interactions. The catalyst properties are the most influential for composition, with partial dependence plots delineating optimal conditions (e.g., 530°C for alkanes and 620°C for aromatics) and suggesting acid-catalyzed conversion of alkenes to aromatics. By bridging empirical correlations with mechanistic insights, this framework enables targeted pyrolysis optimization for high-value oil production. The study advances plastic waste valorization through integrated yield and compositional analysis, providing a transformative tool for sustainable resource recovery and circular economy applications.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107300"},"PeriodicalIF":5.8,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A review on current technologies for plastic waste treatment with focus on pyrolysis for energy recovery","authors":"Bhawna Yadav Lamba","doi":"10.1016/j.jaap.2025.107301","DOIUrl":"10.1016/j.jaap.2025.107301","url":null,"abstract":"<div><div>Plastic waste pollution is a growing global concern as the rate of plastic production continues to rise, far exceeding current recycling capabilities. A significant portion of this waste is discarded into the environment, where it poses serious threats to ecosystems and human health due to its non-biodegradable nature. With traditional recycling proving to be insufficient and economically challenging, there is an urgent need to explore more sustainable and efficient methods for plastic waste disposal. This article presents a critical review of various plastic waste management strategies, focusing particularly on pyrolysis, an emerging thermochemical technique that offers promising results. Pyrolysis involves the thermal degradation of plastic waste in the absence of oxygen, converting it into high-calorific-value products such as pyrolysis oil, syngas, and char. These products can be reused as alternative fuels or chemical feedstocks, supporting both energy recovery and resource circularity. Compared to conventional disposal methods like landfilling and incineration, pyrolysis generates fewer toxic emissions and offers higher material recovery efficiency. As plastic consumption and waste generation are expected to increase, pyrolysis provides a viable, scalable, and environmentally friendly alternative for waste reduction. This review emphasizes the role of pyrolysis as a key technology for plastic depolymerization, highlighting its advantages, limitations, and future potential in the context of sustainable waste management. The adoption of pyrolysis, supported by regulatory frameworks, technological advancements, and public awareness, could significantly reduce the environmental impact of plastic waste while contributing to the development of a circular economy and sustainable energy systems.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107301"},"PeriodicalIF":5.8,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dry distillation of pyrolyzed bio-oils: Exploring the evolution mechanism of heat polymerization in algae-derived bio-oils","authors":"Chuan Yuan ,&nbsp;Jiangshan Zhang ,&nbsp;Mao Chen ,&nbsp;Sivakumar Esakkimuthu ,&nbsp;Bin Cao ,&nbsp;Yamin Hu ,&nbsp;Qi Wang ,&nbsp;Shuang Wang ,&nbsp;Anqing Zheng","doi":"10.1016/j.jaap.2025.107302","DOIUrl":"10.1016/j.jaap.2025.107302","url":null,"abstract":"<div><div>This study systematically elucidates the thermal polymerization mechanism of dry distillation residues from algal bio-oil, with a focus on the transformation pathways of functional groups. The thermal polymerization process involves two main stages. First, low-boiling small molecules undergo crosslinking polycondensation to form polyaromatic frameworks, while non-aromatic moieties undergo cyclic polycondensation to enhance the aromaticity of residues. Subsequently, deoxygenation reactions occur, particularly dehydration/demethoxylation of aromatic structures, and furanyl compounds accelerate polymerization by thermally activated ring-opening to generate carbonyl intermediates. For nitrogen-containing species (pyridine, pyrrole, indole, nitriles), heat treatment promotes chain cleavage of long-chain nitriles into short-chain analogs, accompanied by cyclization-aromatization cascade reactions to form pyridine derivatives and methyl-indoles. Critically, thermal polymerization enables nitrogen heterocycles to graft nitrile/alkyl side chains, forming uniquely structured polymeric frameworks. Multi-scale analysis methods reveal that algal bio-oil coordinates synergistic chemical pathways of aromatic condensation, deoxygenation, and nitrogen reorganization under temperature to form residues. These findings highlight the thermal polymerization characteristics of algal bio-oil, providing a theoretical basis for optimizing dry distillation separation of algal bio-oil and subsequent utilization of residues.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"192 ","pages":"Article 107302"},"PeriodicalIF":5.8,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144704015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}