BIORESOURCE TECHNOLOGY
·
2012
·
IF 4.98
Yan Zhao,Yao Fu,Qing-Xiang Guo
In the present study, γ-valerolactone (GVL) is firstly reported to be converted into aromatic hydrocarbons through catalytic pyrolysis . The catalysts and reaction conditions are both critical in maximizing the hydrocarbon selectivity . Four zeolites , i.e. MCM-41, β-zeolite, ZSM-5 and HZSM-5 were tested in this work, among which HZSM-5 (Si/Al = 25) was found to be the most effective catalyst in both reactivity and selectivity. Under the reaction temperature of 500 °C, the highest carbon yield of 56.71% of aromatics was achieved from GVL with HZSM-5 (Si/Al = 25) as catalyst. Moreover, the HZSM-5 catalyst was recycled for five times without significant decrease in product selectivity.
研究领域:
能源与燃料
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2025
·
IF 14.9
Wenluan Xie,Bin Hu,Guanzheng Zhou,Ji Liu,Zhimo Fang,Zhenxi Zhang,Xiaoyan Jiang,Qiang Lu
Lignin pyrolysis leads to the formation of diverse phenolic products that bear structural similarities to natural lignin, and the related mechanism has been widely explored based on the linkage cleavage-involved reactions. However, some unusual pyrolytic products exhibiting significant structure deviations from lignin, such as aldehydes, remain obscure in mechanism due to long-standing neglect of their formation pathways. The present work found the pivotal role of aryl migration, a special radical-mediated rearrangement process, in governing the formation of these atypical products for the first time. Herein, density functional theory calculations, electronic structure analyses, and pyrolysis experiments were combined to investigate rearrangement patterns and prerequisite structural characteristics of aryl migration by employing typical radicals derived from linkages and substituents of lignin as models. The results indicate that the radical with an unpaired electron located on the second atom of the aromatic side chain can undergo three-membered aryl 1,2-migration triggered by exo cyclization with the best superiority, determining the generation of aldehydes, alkenes, and other products through subsequent cleavage reactions. A clear correlation among the initial geometric and electronic structures of lignin, the patterns and types of aryl migration, the energy barriers, and the end products was established. This study contributes to systematically elucidating rearrangement mechanisms and constructing a more comprehensive lignin pyrolysis mechanism network.
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DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Kai Li,Wan-zhao Huang,Shi-guan Yang,Jia-hao Yu,Qi Niu,Li Zhao,Ying Mo,Yu-han Fan,Qiang Lu
This study developed an innovative method for directional degradation and valorization of waste cellulose acetate (CA) through pretreatment followed with catalytic pyrolysis, enabling the efficient and high-value recovery of CA. A synergistic pretreatment with ethanol and NaOH was employed to modify the molecular structure of CA feedstock. Coupled with phosphoric acid-activated carbon (PAC) catalyzed pyrolysis, the pretreatment-dependent alternation in CA’s physicochemical properties and their effects on pyrolysis to prepare levoglucosenone (LGO) were systematically investigated. The results indicated that the ethanol-NaOH synergistic pretreatment selectively removed the acetyl substituents in CA, exposing more cellulose characteristics, and facilitated the swelling of CA. These modifications enhanced the suitability of CA for selective LGO production. In pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments, the highest yield of LGO from pretreated CA reached 17.84 wt%, significantly exceeding the 2.67 wt% yield gained from untreated CA. This study laid a solid foundation for the efficient and high-value recycling of waste CA.
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产品关联
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Yu Hong,Chengrui Xie,Wanru Chen,Xiang Luo,Kaiqi Shi,Tao Wu
In this study, three primary components of algae (lipid, carbohydrate and protein) and one microalgae (spirulina) were pyrolyzed using a thermogravimetric analyser (TGA) under nitrogen and CO 2 atmosphere at four heating rates . It was found that protein decomposed first, followed by carbohydrate and then lipid. The kinetic study revealed that the lowest activation energy for the initiation of the pyrolysis of ovalbumin (protein) is ∼70 kJ/mol. Oil droplet showed higher activation energy of 266.5 kJ/mol during its pyrolysis in the CO 2 atmosphere, which suggests that algal lipid is more difficult to decompose in the CO 2 atmosphere. However, for the pyrolysis of cellulose (carbohydrate), the activation energy (∼310 kJ/mol) is similar under two different gas atmospheres tested. This study showed that CO 2 atmosphere favors the pyrolysis of algae with high protein content and low lipid content, since the existence of CO 2 promotes the cracking of VOCs (volatile organic compounds) as well as the reaction between VOCs and CO 2 .
研究领域:
能源与环境科学
·
生物化学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Yan Zhang,Yaqi Wang,Zhengyu Chen,Quan Shi,Linzhou Zhang
Pyrolysis has emerged as a key approach for converting plastic waste into valuable resources. However, this process is an extremely complex reaction system, and the molecular conversion behavior and pathways have not been fully understood. This study systematically investigated the thermal pyrolysis of polypropylene (PP) over a temperature range of 420–500 °C, and the composition of PP pyrolysis oils was analyzed using Ag + complexation electrospray ionization high-resolution Orbitrap mass spectrometry. The results indicate that the pyrolysis oils are primarily composed of mono-olefins and diolefins at lower temperature and pressure, with a three-carbon repeating unit. Secondary reactions intensified at elevated temperatures and pressure, progressively converting heavy olefins to polycyclic aromatics. The results of mass spectrometry analysis were compared with gas chromatography showing significant advantages, and were in good agreement with the molecular structure information provided by nuclear magnetic resonance hydrogen spectroscopy and Fourier transform infrared spectroscopy. Furthermore, the PP pyrolysis pathways at varying temperatures were proposed showing the full pathway of cracking and aromatization.
研究领域:
环境科学
·
化学工程
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Yixuan Zhang,Geliang Xie,Guoqiang Zhu,Lujiang Xu
This study systematically investigated the influence of urea, an active nitrogen, on the pyrolysis behavior of lignin. Thermogravimetric analysis (TGA) and kinetic analysis were employed to elucidate the synergistic effect of reaction pathway modulation and product distribution optimization between urea and lignin. The results indicated that urea significantly reduced lignin pyrolysis activation energy (E), with a maximum reduction of 254.14 kJ/mol (lignin+50 % urea) and average energy decreasing to 87.28 kJ/mol. Meanwhile, it induced a transition from the nth-order reaction to the geometric contraction. Moreover, urea effectively inhibited the formation of complex phenolic and hydrocarbon substances, elevating the proportion of simple phenols in bio-oil to about 40 % while promoting formation of pyridine-N and pyrrole-N structures in bio-char, which increased the nitrogen content from 2.00 % to 2.71 %. The experiments also found that NH 3 and free radicals derived from urea decomposition could participate in the free-radical reactions of lignin, promoting the cleavage of C-O and C-H bonds and hydrogenation and deoxygenation, thereby achieving the regulation of product selectivity. Urea offers an efficient and feasible technical route for the directional conversion of lignin into high-value chemicals with promising application prospects.
研究领域:
化学工程
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生物化学
·
材料科学
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能源与燃料
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2025
·
IF 7.4
Ya Xue,Ying Li,Fei Zhong,Zhongxiang Bai,Pan Wang,Kui Li,Fan Lei,Zhoukun He,Yang Yang,Wei Feng,Xulin Yang
Traditional benzoxazines are largely constrained by the dependence on non-renewable resources, solvent-based synthesis, and insufficient thermal resistance. This study presents a novel high-performance bio-based benzoxazine containing phthalonitrile (BZPN), synthesized via melt condensation using eugenol, 3-aminophenoxyphthalonitrile, and paraformaldehyde. The chemical formula of BZPN was validated by FTIR, ¹H and ¹³C NMR analyses. The curing of BZPN involves ring-opening polymerization of oxazine group and ring-forming polymerization from phthalonitrile unit, yielding polybenzoxazines and heteroaromatics respectively. Combined TG-DTG, TG-FTIR with TG-MS technique, the three-stage thermal pyrolysis mechanism of BZPN was proposed. The initial decomposition ( T dm1 =395 °C) occurs through the cleavage of C N, C O, and C C bonds in the polybenzoxazine, releasing NH₃, H₂O, CH₄, and CO₂. The second stage ( T dm2 =485 °C) involves the cleavage of C O and C C bonds in the heteroaromatic networks by releasing NH₃, H₂O, CH₄, and CO₂. The final carbonization stage ( T dm3 =615 °C) includes the transformation of highly aromatic compounds into graphite. With the facile solvent-less synthesis method and superior comprehensive properties (compressive strength: >220 MPa, T g : >375 °C, T d5 : >390 °C, and C y : 72 % at 800 °C), bio-based BZPN is a promising high-performance thermosetting resin for advanced industrial and engineering applications.
研究领域:
高分子化学
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材料科学
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有机合成
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热分析
✓ 已验证
产品关联
DOI
高影响因子
Nano Select
·
2021
·Vol. 2
·期 9
·1770-1778
·
IF 0
Xiaoyan Wang,Axel Funke,Ya-Jun Cheng,Fang Song,Shanshan Yin,Suzhe Liang,Xiuxia Zuo,Jie Gao,Peter Müller-Buschbaum,Yonggao Xia
Continuous fast pyrolysis is developed for in situ synthesis of ultra-small metal oxide nanoparticles embedded into three-dimensional macroporous carbon matrix as demonstrated by the TiO 2 /carbon nanohybrid. The TiO 2 nanoparticles with the average size of 4.6 nm ± 0.6 nm are uniformly distributed in the in situ generated macroporous carbon matrix. When evaluated as an anode in a lithium-ion battery, the macroporous TiO 2 /C nanohybrid exhibits a reversible capacity of 483 mAh g –1 after 500 cycles at a current density of 67 mA g –1 , which is 3.6 times higher than that of the TiO 2 /C calcined in a conventional batchwise way. Besides, the capacity retains 93 mAh g –1 at a high current density of 670 mA g –1 . It reveals that the continuous fast pyrolysis is an efficient method to fabricate carbon composition based metal oxides as lithium-ion battery anode materials.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
RSC Sustainability
·
2024
·Vol. 2
·期 12
·3916-3928
·
IF 0
Qinxu Li,Bo Chen,Songyuan Yao,Chao Sang,Lu Lu,Shilong Dong,Hui Cao,Zhihao Si,Peiyong Qin
Polyimide (PI) membranes have shown great advantages in gas separation due to their excellent thermal and chemical stability as well as high separation performance. With the increased demand for PI membranes, their recycling is a challenge for sustainable development. In this work, we systematically studied the pyrolysis behavior and performed kinetic analysis of a Kapton polyimide membrane, which has been suggested to exhibit a high gas separation performance. Results showed that the pyrolysis of the polyimide membrane was divided into three stages revealed by Py-GC/MS, with the main products being CO2, CO, and H2O. To study the pyrolysis kinetics of the polyimide in the main conversion range, the FWO, KAS, and Starink methods were adopted. The average activation energies were found to be 284.6, 286.1, and 286.5 kJ mol−1, respectively. The pyrolysis of the polyimide membrane followed second-order (F2) and third-order (F3) models. Consequently, the pyrolysis technique provides valuable guidance for the recycling of polyimide membranes.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
FUEL
·
2022
·
IF 8.035
Yang Ren,Chengyang Cao,Hongyun Hu,Su Lei,Xiangzhou Yuan,Xian Li,Hong Yao
Polychloroprene (PCP) rubber is mostly mixed in industrial solid waste (ISW) as the main source of chlorine element. Whereas, the products formation and chlorine behavior during the pyrolysis are insufficiently illustrated for this typical chlorinated polymer, which is not conducive to the chlorine regulation of ISW pyrolytic products. In order to investigate the chlorine transformation behavior, the PCP pyrolysis under the influence of a wide range of heating rates (3–600 °C/min) was conducted to explore the chlorine distribution properties as well as its migration mechanism in the present study. Importantly, 30–65 wt% chlorine was found to be migrated to gas and tar, respectively. Compared with PVC , the differences of chlorine distribution between PCP and PVC may be attributed to the easier cyclization with a longer molecular chain. Also, the release temperature of HCl acted as main component determines its availability for the subsequent formation of chlorinated hydrocarbons. In details, the conversion pathway from chlorinated limonene to Cl-aromatic hydrocarbons was confirmed and the reaction was found to be enhanced at higher temperature and heating rate. By analyzing the content of tar components (especially at low heating rate), it was found that the major formation pathway of aromatic hydrocarbons was supposed to be the direct Diels-Alder reaction of monomer rather than the dechlorination of intermediate chlorinated limonene. Our findings discussed the effect mechanism of heating rate and temperature on chlorine behavior during PCP pyrolysis, providing guidance for the chlorine regulation of ISW pyrolytic products.
研究领域:
环境科学
·
聚合物热解
·
废物处理
·
氯化学
·
热转化
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY A
·
2021
·
IF 2.781
Minggao Xu,Baozhong Zhu,Long Zhao,Yunlan Sun,Yang Pan,Jiuzhong Yang
The pyrolysis of chlorobenzene (C6H5Cl) at 760 Torr was studied in the temperature range of 873–1223 K. The pyrolysis products including intermediates and chlorinated aromatics were detected and quantified via synchrotron radiation photoionization mass spectrometry. Furthermore, the photoionization cross sections of chlorobenzene were experimentally measured. On the basis of the experimental results, the decomposition pathways of chlorobenzene were discussed as well as the generation and consumption pathways of the main products. Benzene is the main product of chlorobenzene pyrolysis. Chlorobiphenyl (C12H9Cl), dichlorobiphenyl (C12H8Cl2), and chlorotriphenylene (C18H11Cl) predominated in trace chlorinated aromatic products. Chlorobenzene decomposed initially to form two radicals [chlorophenyl (·C6H4Cl) and phenyl (·C6H5)] and the important intermediate o-benzyne (o-C6H4). The propagation processes of chlorinated aromatics, including polychlorinated naphthalenes and polychlorinated biphenyls, were mainly triggered by chlorobenzene, chlorophenyl, and benzene via the even-numbered-carbon growth mechanism. Besides, the small-molecule products such as acetylene (C2H2), 1,3,5-hexatriyne (C6H2), and diacetylene (C4H2) were formed via the bond cleavage of o-benzyne (o-C6H4).
研究领域:
物理化学
·
燃烧化学
·
环境化学
·
质谱分析
·
反应机理
✓ 已验证
DOI
高影响因子
Processes
·
2025
·Vol. 13
·期 11
·3543
·
IF 2.8
Zhen Zhao,Meng Chen,Lei Wang
This study investigates the torrefaction of polyvinyl chloride (PVC) and cellulose, two major constituents of agricultural waste, with the aim of improving chlorine removal and enhancing the energy quality of the resulting solid products. Thermodynamic simulations using HSC Chemistry 9.0 were first conducted to predict equilibrium compositions, particularly chlorine-containing species. Thermogravimetric analysis (TGA) and coupled TGA-FTIR were employed to monitor mass loss and identify gaseous chlorine compounds. Based on these preliminary results, torrefaction experiments were carried out at temperatures of 250–300 °C and durations of 30–90 min. The results demonstrate a significant synergistic effect between cellulose and PVC during co-torrefaction, achieving 97% chlorine removal under optimal conditions (9:1 cellulose-to-PVC ratio, 250 °C, 30 min). This effective dechlorination helps mitigate Cl-induced corrosion and reduces the risk of dioxin formation in industrial applications, enabling the sustainable upcycling of PVC-contaminated biomass into clean solid fuels. Torrefaction temperature exerted a stronger influence than time on mass loss, yielding approximately 40% solid residue at 300 °C. While both solid and energy yields decreased with increasing temperature and time, the O/C and H/C atomic ratios decreased by 56% and 48%, respectively, indicating a substantial improvement in fuel properties. The observed synergy is attributed to cellulose-derived hydroxyl radicals promoting PVC dehydrochlorination. This process offers a scalable and economically viable pretreatment route for PVC-containing biomass, potentially reducing boiler corrosion and hazardous emissions.
研究领域:
能源工程
·
废物资源化
·
热化学转化
·
环境科学
·
可持续燃料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）