JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2025
·
IF 6.2
Zhi Li,Kai Shen,Min Hu,Miao Liu,Fang Zhou,Ming Li,Qiong Liu,Xiaoxu Wu,Weiwang Chen
Polyimide aerogels (PIAs) have extensive application prospects in numerous fields for their appealing characteristics, including low density, superior thermal stability, high flexibility, and remarkable mechanical properties. However, the thermal safety of polyimide aerogels in practical applications has been neglected, the pyrolysis behaviors and reaction kinetics need to be clarified. In this work, PIAs with different repeat units from 10 to 60 were prepared using the sol-gel method, and the effect of repeat unit on the basic properties, microstructure, and thermal stability of polyimide aerogel was studied. The PIAs with a repeat unit of 40 have the lowest density, thermal conductivity, radial shrinkage, the highest porosity, the largest specific areas, and so on. Furthermore, the pyrolysis process and products of PIA were analyzed by TG-FTIR-MS. The pyrolysis kinetic parameters were calculated by model-free method and the predicted reaction model was chosen by CR and Malek method. The calculated kinetic parameters are in good agreement with the experimental data at different heating rates, which can guide the pyrolysis behavior and thermal safety of polyimide aerogels.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Bo Liang,Jianghuai Hu,Ping Yuan,Chengfeng Li,Renke Li,Yao Liu,Ke Zeng,Gang Yang
Accurately modeling the kinetics of the pyrolysis reaction of phthalonitrile resin was helpful to investigate the pyrolysis mechanisms. To study the pyrolysis kinetics, phthalonitrile resin was measured by thermogravimetric analysis (TGA) at different heating rates in flowing nitrogen. The results indicated that there were two consecutive and overlapping stages in the pyrolysis process. The overlapped peaks were separated by multi-peak fitting method. Two models, namely, Kissinger, Kissinger-Akahira-Sunose (KAS), were employed to calculate activation energy at various stages of pyrolysis process. Kinetic models were determined using the differential method and Coats-Redfern method. Based on the attained kinetic models and activation energy values, the pre-exponential factor values were determined by KAS method. According to the calculated apparent activation energies, the most probable kinetic mechanism functions and pre-exponential factors, the simulated data agreed well with the experimental data.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Sizhao Zhang,Jian Feng,Junzong Feng,Yonggang Jiang,Feng Ding
Although carbon aerogels derived from naturally occurring materials have been developed extensively, a reasonable synthetic approach using cellulose-resource remains unclear. Here, we report a strategy to prepare carbon aerogels originated from cellulose position-selectively oxidized by TEMPO-oxidized process. Contrary to non-TEMPO-oxidized cellulose-derived carbon aerogels (NCCA) with relative loose structure, TEMPO-oxidized cellulose-derived carbon aerogels (TCCA) with tight fibrillar-continuous network are monitored, suggesting the importance of TEMPO-oxidized modification towards creating the architecture of subsequently produced carbon aerogels. TCCA endows a higher BET area despite owning slightly dense bulk density comparing with that of NCCA. The structural texture of TCCA could be maintained in a way in comparison to TEMPO-oxidized cellulose-derived aerogel, due to the integration and aggregation effect by losing the electric double layer repulsion via ionization of the surface carboxyl groups. FTIR and XPS analyses signify the evidence of non-functionalized carbon-skeleton network formation in terms of TCCA. Further, the mechanism concerning the creation of carbon aerogels is also established. These findings not only provide new insights into the production of carbon aerogels but also open up a new opportunity in the field of functional carbon materials.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Xiaoliang Zhang,Yufei Xie,Haobo Wang,Li Wang,Guangyuan Tao,Ronghan Guo,Jun Zhang,Yanli Zhao,Hongbing Ji
Porous materials have received extensive attention due to their superior adsorption properties, but there are few studies on oil adsorption. In this paper, a new self-design high-temperature reactor carried out MCC adsorption experiments, and a complete test system was used to study the adsorption characteristics, pyrolysis kinetics and pyrolysis products. The results of SEM and XRD showed that G 3 H gradually wetted the surface of MCC and the crystallinity increased. In addition, the pyrolysis parameters of MCC-adsorption-G 3 H (MAG) were measured by DSC and STA. The results showed that MCC was pyrolyzed in one step while MAG was in two. Meanwhile, thermodynamic model fitting indicated that the first stage was Fn and the second was Cnm autocatalytic. Notably, the variation of pyrolysis activation energy in the first stage was similar to that of adsorption capacity. Pyrolysis products of G 3 H were measured by Py-GC-MS, and pyrolysis residues of MAG were tested by FTIR. Combined with the volatiles determined by TG-IR, the influence of G 3 H on the pyrolysis characteristics was obtained, and the pyrolysis path of MAG was summarized. The results showed that porous materials can recycle oil and provided a guideline for industrial production.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Zexia Li,Jingwen Yang,Hejun Gao,Jiaxiao Qiao,Wei Qiao,Peng Wang,Jun Zhang,Chengchun Tang,Yanming Xue
Microspheric BN materials have high application potential because they have better fluidity and dispersion ability to endow hexagonal boron nitride (h-BN) ceramics and h-BN/polymer composites with highly desired performance. In this work, a novel synthetic route to the BN microspheres has been developed by means of a controllable pyrolysis of polymerized spherical precursors. The precursor formation mechanism is proposed to be the F-127-induced self-assembling polymerization of a boric acid–melamine–formaldehyde (MF) colloid. It is found that ammonia-annealing of an air-pyrolysis (700 °C) intermediate causes higher BN phase transformation within final BN microspheres with more uniform diameter distribution compared to those of direct ammonia-pyrolysis of spherical precursors at the same temperatures of 1100 and 1500 °C. After ammonia-annealing and ammonia-pyrolyzed treatment at 1100 and 1500 °C, the obtained BN microspheres have a low specific surface area (SSA) property, but replacing part of melamine with dicyandiamide could increase their SSAs to more than 1000 m2/g. We believe that this new microspherical BN preparation with more facile and controllable operation would be well suited for industrialization.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2026
·
IF 7.8
Yi Huang,Yongda Huang,Aijun Li,Yuhang Zheng,Binbin Fu,Nanxi Bie,Hongyun Hu,Xian Li,Hong Yao
The escalating generation of medical waste, characterized by complex composition and high chlorine content, poses severe challenges for its clean treatment. Pyrolysis offers a promising route for thermochemical conversion of medical waste into high-value products, achieving sustainable treatment of medical waste. However, a limited understanding of how pyrolysis parameters influence product formation and chlorine transformation restricts its practical application. This study investigated the influence of temperature (500–700 ℃) and heating rate (60–6000 ℃/min) on medical waste pyrolysis for sustainable high-value products. For product formation, temperature primarily governed bond cleavage and secondary cracking, thereby enhancing syngas production (H 2 , CH 4 , CO) and promoting decomposition of oxygenated polymers and plasticizers. In contrast, heating rate mainly controlled volatile residence time, with rapid heating suppressing secondary reactions, preserving bis(2-ethylhexyl) phthalate and aromatic intermediates in tar. The char structure became more graphitic with increasing temperature and heating rate. For chlorine transformation, increasing temperature facilitated C-Cl bond cleavage, directing the majority of chlorine into the gas phase predominantly as inorganic HCl, a readily removable chlorine species in downstream treatment. Conversely, fast heating redirected chlorine toward condensed phases, mainly fixing it as NH 4 Cl in tar and as metal chlorides (KCl, NaCl) in char. The formation of representative organochlorines, including 3-(chloromethyl)heptane and 1-chloroethylbenzene, was selectively regulated by temperature and heating rate, respectively. Overall, this study establishes a framework for simultaneously optimizing product formation and steering chlorine toward easily removable inorganic species, supporting the sustainable thermochemical treatment of medical waste.
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2020
·
IF 5.627
Yan Zhang,Xiaoyuan Zhang,Chuangchuang Cao,Jiabiao Zou,Tianyu Li,Jiuzhong Yang,Lili Ye,Yuyang Li
This work reports an experimental and kinetic modeling investigation on the flow reactor pyrolysis of iso -butylbenzene and tert -butylbenzene at 0.04 and 1 atm. Pyrolysis products were detected and identified using synchrotron vacuum ultraviolet photoionization mass spectrometry , and their mole fractions versus heating temperature were measured. High-pressure-limit and pressure-dependent rate constants of unimolecular decomposition reactions of iso -butylbenzene were calculated in this work using the same method as the theoretical calculation investigation on similar reactions of n -butylbenzene, sec -butylbenzene and tert -butylbenzene reported by Belisario-Lara et al. [ J. Phys. Chem. A , 122 (2018) 3980–4001]. Furthermore, a pyrolysis model of four butylbenzene isomers was developed from our previous models of n -butylbenzene and sec -butylbenzene and validated by the present experimental data. Modeling analysis was performed to reveal key pathways in fuel decomposition and polycyclic aromatic hydrocarbon (PAH) formation of iso -butylbenzene and tert -butylbenzene. The dominant decomposition reactions of iso -butylbenzene and tert -butylbenzene under pyrolysis conditions are benzylic C C bond dissociation reactions, while the major products in pyrolysis process are produced by β - scission reactions of primary radical products. Fuel-specific pathways are found to strongly affect the formation of PAHs, especially for indene, naphthalene and phenanthrene. Fuel isomeric effects on the pyrolysis of four butylbenzene isomers were also analyzed with special concerns on the fuel decomposition and PAH formation processes. Different sidechain structures result in different distributions of major products, while different formation pathways and concentrations of precursors lead to different formation tendency of typical PAHs.
研究领域:
化学工程
·
燃料化学
✓ 已验证
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 5
·3871-3880
·
IF 4.987
Zhang Liqiang,Li Shanshan,Yang Zhengda,Wang Xinwei,Li Dawei,Lin Riyi
To explore a new way of utilizing lignin and deepen the understanding of mechanism of two-step pyrolysis (TSP) of biomass, the effects of the first step pyrolysis temperature (T1) and residence time (RT1) on TSP of lignin were studied by using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). TSP of lignin was also compared with one-step pyrolysis (OSP) of lignin. The results indicated that higher pyrolysis temperature promoted the break of ether linkage among the structural elements of lignin and the removal of side chains. With T1 increasing, the contents of monophenols (MPs), catechols (CPs), monocyclic aromatic hydrocarbons (MAHs), and polycyclic aromatic hydrocarbons (PAHs) increased in the first step, while the contents of methoxyphenols with double bond in the side-chain (MPBSs) and methoxyphenols with no double bond in the side-chain (MPSs) increased firstly and then decreased. In the second step, with T1 increasing the contents of MPs and CPs increased firstly and then decreased, the contents of MAHs and PAHs increased significantly, and the contents of MPBSs and MPSs decreased. Higher T1 increased the yields of the most identified compounds of the first step, but decreased the yields of MPs, CPs, MPBSs, and MPSs in the second step. RT1 had great effects on the pyrolysis behaviors and product distribution of TSP of lignin, and the content of MAHs and PAHs in the second step increased significantly with RT1 increasing. Compared with OSP, the yields of MAHs and PAHs could increase in the second step. TSP of lignin could improve the selectivity of value-added chemicals remarkably, such as guaiacol, vanillin, acetovanillone in the first step, and the selectivity of benzene, toluene, m-xylene, phenol, o-cresol, and p-cresol in the second step.
研究领域:
生物质能
·
化学工程
·
分析化学
✓ 已验证
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2024
·
IF 5.3
Qilong Fang,Jun Fang,Yi Zhang,Jianguo Zhang,Tianyou Lian,Wei Li,Yuyang Li
Oxymethylene ethers (OMEs) have received great attention due to their carbon-neutral nature and advantageous properties as alternative transportation fuels or fuel additives. Previous studies focused on the combustion of linear OMEs with the chemical formula of CH 3 O(CH 2 O) m CH 3 ( m ≥ 0), while a deep understanding of the combustion of branched OMEs with the chemical formula of CH 3 OCH 3- n (OCH 3 ) n (0 ≤ n ≤ 3) is still absent. In this work, the flow reactor pyrolysis of dimethoxymethane (DMM, n = 1), trimethoxymethane (TMM, n = 2), and tetramethoxymethane (TeMM, n = 3) is investigated using gas chromatography, with special attention given to the multi-sidechain effects on the pyrolysis chemistry. A pyrolysis model of branched OMEs is developed and validated against the new pyrolysis data. Modeling analysis is performed to provide insights into the pyrolysis chemistry of the three branched OMEs and the multi-sidechain effects. Unimolecular decomposition and H-abstraction reactions are found to be two major types of fuel decomposition pathways, with the former dominating TMM decomposition, the latter dominating DMM decomposition, and both contributing almost equally to TeMM decomposition. Sensitivity analysis shows that C O bond dissociation is the most sensitive reaction to fuel decomposition in DMM pyrolysis, while methanol elimination is the most sensitive reaction in TMM and TeMM pyrolysis. Among the three fuels, DMM has the lowest pyrolysis reactivity and produces the least abundant methanol. In contrast, TMM is observed with the highest pyrolysis reactivity and produces the most abundant methanol. Theoretical calculations reveal that TMM and DMM have the lowest and highest energy barriers of methanol elimination reactions, which determines the order of their pyrolysis reactivities and methanol formation trends. As a result, DMM pyrolysis occurs at higher temperature regions where the C O bond dissociation and H-abstraction reactions are preferred, while TMM pyrolysis occurs at lower temperature region where methanol elimination dominates.
研究领域:
能源科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2017
·
IF 5.651
Huiyan Zhang,Shanshan Shao,Mengmeng Luo,Rui Xiao
Catalyst deactivation is the main reason for low petrochemical yield in catalytic fast pyrolysis (CFP) of biomass. ZSM-5 catalysts modified by chemical liquid deposition (CLD) and acid dealumination (AD) were prepared to improve petrochemical yields for CFP of pinewood. The results showed that CLD by SiO 2 led to the coverage of strong acid sites, while AD favored the removal of superficial acid sites. CFP of pinewood showed that the relative area ratio of BTX was boosted by 37.2% and 30.4% over modified ZSM-5 catalysts by CLD and AD, respectively. The yield of indenes and naphthalenes which were important precursors of heavy coke decreased sharply. Considering environmental cost and catalytic performance, CLD seems to be a preferable modification method over ZSM-5 in the catalytic pyrolysis of biomass for petrochemicals.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2020
·
IF 4.748
Wei Luo,Qing Hu,Zhong-yi Fan,Jun Wan,Bin Luo,Zhi-xiang Yan,Sheng-Xiong Huang,Zhi Zhou
Reworked synthetic polymers (RSPs) are industrial raw materials obtained from waste synthetic polymer (WSP) through physical or chemical means. Different reworked synthetic polymers have different pyrolysis characteristics and synergistic reactions during co-pyrolysis process. The effect of reworked polyamide 6 (PA6), thermoplastic elastomer (TPE), black polypropylene (PP1) and green polypropylene (PP2) co-pyrolysis on the yield and quality of pyrolysis products has been conducted. The results show that co-pyrolysis promotes the degradation of RSPs into more gases. Co-pyrolysis improves the light component of liquid oils and reduces the O content, which is beneficial for liquid fuels. Except for TPE + PP2, co-pyrolysis of RSPs increased di-aromatics, poly-aromatics and aromatic compounds. TPE + PP2 and PP1+PP2 produced high aliphatic compounds including the long chain aliphatic compounds without sufficient degradation, which resulted in the contents of over C 20 were high. In the pyrolysis gases , the relative content of H 2 was increased in all mixed RSPs co-pyrolysis, which can be used as clean fuels. The X-ray diffraction (XRD) analysis shown that new components were found and old components disappeared in co-pyrolysis, indicating chemical reaction had occurred between two different types of RSPs.
研究领域:
环境科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY A
·
2018
·
IF 2.836
Yamin Li,Qinghui Meng,Jinglan Wang,Yan Zhang,Chuangchuang Cao,Zhanjun Cheng,Jiuzhong Yang,Fuyi Liu,Lidong Zhang,Yang Pan
The thermal decomposition of furfural is investigated in a flow tube reactor at 30 Torr by synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) at temperatures from 1023 to 1273 K. Over 20 kinds of pyrolysis products, including short-lived radicals, stable oxygen-containing compounds, and hydrocarbons, are identified from the scanning photoionization efficiency (PIE) spectra. Vinylketene (CH2═CH–CH═C═O), which has been shown to be an important primary product, is also directly observed. The possible steps of hydrogen atom addition and hydrogen atom abstraction in the thermal decomposition of furfural are studied by theoretical calculations at the CBS-QB3 level. In addition to unimolecular decomposition, hydrogen atom addition followed by ring opening can lead to the production of vinylketene.
研究领域:
物理化学
·
燃烧化学
·
反应机理
·
质谱分析
·
理论化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）