ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 36
·50500-50509
·
IF 4.223
He Qian,Huang Shengxiong,Luo Wei,Su Yifeng,Xia Mao,Zhou Nan,Zhou Zhi
In-situ catalytic pyrolysis has simple process configuration and low cost. Ex-situ catalytic pyrolysis can optimize the pyrolysis capacity and upgrade catalysis, and the catalytic can be reused. But there have been few studies researched on compare in-situ and ex-situ catalytic pyrolysis of the OS performed in similar reactor with two kinds of catalytic. This paper study the pyrolysis of oily sludge (OS) uses CaO and oily pyrolysis char as catalytic at 700 °C. Through analysis the pyrolysis oil (PO), pyrolysis solid (PS) and pyrolysis gas (PG) during pyrolysis procedure to research the difference between in-situ and ex-situ catalytic pyrolysis. The gas chromatography-mass spectrometry (GC-MS) results show that CaO was conducive to the synthesis of aromatics, which content more than aliphatics and heterocyclics in CaO-i (i: in-situ) and CaO-e (e: ex-situ) groups. However, char greatly inhibits the production of aromatic compounds and promotes the production of aliphatic compounds. Gas chromatography (GC) results present that the char and CaO can greatly increase the content of combustible gas and the content reach to 85.85%, the pyrolysis gas (PG) keep at the highest combustion performance in char-CaO-i group. Meanwhile, compared with uncatalyzed groups, the content of CH 4 and CO increased about 2.05% and 3.93%, respectively. Fourier transform infrared spectroscopy (FT-IR) show that char and CaO reduce the function groups number of pyrolysis solid (PS), and it shows that the pyrolysis reaction is more complete. This research is expecting to provide theory support for catalytic pyrolysis of OS.
研究领域:
环境科学
·
能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2025
·
IF 9.1
Zhen He,Quanwei Lv,Xia Jiang,Yang Su,Guangmei Cao,Xianggang Zhang,Lingling Xie,Haijun Wu
The co-pyrolysis of straw and polyethylene (PE) enhances pyrolysis oil quality by reducing oxygenated compounds and increasing hydrocarbons. However, the synergistic mechanisms between straw's main components (cellulose, hemicellulose, and lignin) and PE are not well understood. This study investigated these interactions, revealing a two-stage reaction: cellulose and hemicellulose dominate the first stage, while PE and lignin dominate the second. Significant synergistic effects were observed at 550 °C during the co-pyrolysis of straw and PE, resulting in at least a 17.84 % increase in alkanes and a decrease in oxygenated compounds. Free radicals from PE facilitated the cleavage of carbonyl bonds and promoted deoxygenation, leading to more hydrocarbons. Hemicellulose inhibited ester conversion (ΔV esters = −3.00 %), while lignin suppressed ketone and alcohol formation (ΔV ketones = −12.14 %, ΔV alcohols = −1.07 %). These findings align with straw-PE co-pyrolysis results, providing new insights into the synergistic mechanisms between lignocellulosic biomass and plastics.
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2012
·
IF 2.487
Xinlai Wei,Qiang Lu,Xianwei Sui,Zhi Wang,Ying Zhang
Water-insoluble pyrolytic cellulose with similar appearance to pyrolytic lignin was found in cellulose fast pyrolysis oil. The influence of pyrolysis temperature on pyrolytic cellulose was studied in a temperature range of 300–600 °C. The yield of the pyrolytic cellulose increased with temperature rising. The pyrolytic cellulose was characterized by various methods. The molecular weight distribution of pyrolytic cellulose was analyzed by gel permeation chromatography (GPC). Four molecular weight ranges were observed, and the M w of the pyrolytic cellulose varied from 3.4 × 10 3 to 1.93 × 10 5 g/mol. According to the elemental analysis (EA), the pyrolytic cellulose possessed higher carbon content and lower oxygen content than cellulose. Thermogravimetric analysis (TGA) indicated that the pyrolytic cellulose underwent thermo-degradation at 127–800 °C and three mass loss peaks were observed. Detected by the pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), the main pyrolysis products of the pyrolytic cellulose included saccharides, ketones, acids, furans and others. Fourier transforms infrared spectroscopy (FTIR) also demonstrated that the pyrolytic cellulose had peaks assigned to C O stretching and glycosidic bond, which agreed well with the Py-GC/MS results. The pyrolytic cellulose could be a mixture of saccharides, ketones, and their derivatives.
研究领域:
生物质能
·
材料化学
✓ 已验证
产品关联
DOI
高影响因子
Waste and Biomass Valorization
·
2016
·Vol. 9
·期 1
·123-130
·
IF 0.915
Cheng Xu,Tang Yijing,Wang Biao,Jiang Jianming
The utilization of waste rice husks for biochar production has received much attention due to the energy concerns and environmental issues. But how to increase the charcoal yield and quality remains a big challenge. In this work, a two-step pyrolysis of rice husks was carried out at atmospheric pressure, consisting of a first low heating rate step followed by a high heating rate step. The effects of operation conditions at each step, including temperature, heating rate and residence time, on changes in charcoal yield and quality based on fixed-carbon yield were investigated. At the first step, switch temperature and heating rate were the predominant factors that influenced charcoal and fixed-carbon yields. The increase of charcoal and fixed-carbon yields at the first step was attributed to the rate-determined decomposition of hemicellulose. Therefore, the switch temperature should be set at those lower than the decomposition temperature of celluloses. However, at the second step, decreasing final pyrolysis temperature and shortening residence time benefited the increase of charcoal yields. Whereas, a maximum value of fixed-carbon yield was observed at the final pyrolysis temperature of 600 °C, which could result from the aromatics formed from cellulose-derived volatiles. Therefore, the switch temperature should be lower than cellulose decomposition temperature in order to reduce the cycle time for biochar production. Moreover, the charcoal and fixed-carbon yields obtained by the optimized two-step pyrolysis were higher than those by one-step pyrolysis.
研究领域:
能源与环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yuan Zeng,Yuanyuan Wang,Linyao Ke,Qiuhao Wu,Xiaojie Tian,Liangliang Fan,Kirk Cobb,Yuhuan Liu,Roger Ruan,Yunpu Wang
The pyrolysis of metal soaps to produce hydrocarbon rich fuel has been studied extensively. However, the combined effects of microwave radiation and metal ion types on hydrocarbon production have not been addressed. In this study, the microwave and conventional pyrolysis experiments were conducted on five metal soaps (Li soap, Na soap, K soap, Ca soap, Mg soap). The results demonstrated that the metal ions at the carboxyl end of the soap enhanced the polarity of the reactants, leading to a rapid increase in temperature under microwave conditions. With the ion radius increasing, the heating rate increased gradually. Compared with conventional pyrolysis, microwave pyrolysis exhibited a more rapid heating rate, a higher degree of carbon chain fracture, and a greater abundance of small olefin compounds, which promoted aromatization reaction and the release of CO, H 2 and CH 4 . In addition, the composition of the pyrolysis products derived from different metal soaps is affected by the characteristics of metal ions. As the radius of metal ions increased, the oxygen content in the liquid products decreased gradually, while the carbon content increased. The strengthening effect of microwave was further analyzed. With the increase in the radius of metal ions, the strengthening effect of microwaves on olefins formation was gradually weakened, while the inhibiting effect on alkanes formation was gradually enhanced. The structure of carboxylate network is affected by the radius of metal ions, which results in the regular change of the strengthening effect of microwave on olefins and other products. This study is highly significant in guiding the pyrolysis of soapstock waste to prepare olefins and alkanes with high efficiency and low energy consumption.
研究领域:
能源化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yuxin Wen,Wenqing Lv,Yilong Xu,Liangyan Ma,Haoquan Hu,Lijun Jin
Pyrolysis is a potential approach to treat post-consumer waste natural rubber (NR), however, unclear pyrolysis mechanism restricts its actual utilization. In this work, thermal degradation of NR was investigated combining dynamical method with pyrolysis on the infrared-heating fixed-bed reactor. Results show that thermal degradation of NR is an apparently exothermic and multistep reaction, tar yield reaches up to 96.59 wt%. Pyrolysis tar mainly consists of cycloolefin with a small quantity of chain olefins and mono-ring aromatic hydrocarbons. High temperature reduces the cycloolefin yield but promotes the generation of mono-ring aromatic hydrocarbons. Tar is mainly composed of dimer (C10) or trimer (C15) of isoprene with different structures. H type in tar is mainly aliphatic hydrogen. Besides, a possible pyrolysis mechanism based on the β bond breakage was proposed. The work can provide a theoretical basis for direct control of high value-added products during NR pyrolysis and achieve high efficiency pyrolysis of NR.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Wu Jian,Chen Zhen,Wang Jun,Wang Yiqun,Jiang Jian,Xiao Weiqiang,Xia Qian,Zhang Jiabao,Zhou Guojun,Zhang Junsong,Liang Miao
Cigar tobacco residues are a special air-cured tobacco material with increasing production in domestic. In this present study, the effect of glycerol addition on the pyrolysis characteristic, kinetic behavior, and release of pyrolytic products was investigated by using thermogravimetry coupled with online FTIR and self-built infrared tubular furnace. The thermal weight loss process of cigar tobacco could be divided into four stages, and the glycerol exhibited significant impact on the pyrolysis process. The stage II corresponding the decomposition of volatile components and hemicellulose shifted to the lower temperature accompanied with an increase of DTG max and weight loss at this stage. The T i , T f , and residues were decreased, while the CPI was increased as for the CT-G sample, indicating an increased reactivity and comprehensive pyrolysis performance. Gauss peak fitting was used to separate the pyrolysis process of different pseudocomponents in the tobacco biomass. Pyrolysis kinetic analysis based on Coats-Redfern method showed that the activation energy for the decomposition of each pseudocomponents decreased after the addition of glycerol. The online FTIR and MS analysis also reflected the interaction between glycerol and biomass through the release of pyrolytic gaseous products. GC–MS was further used to analyze the compositions of pyrolytic products in the trapped particulate matter under different heating rates. High heating rate was beneficial for the sufficient release of pyrolysis products and aroma compounds. The glycerol addition inhibited the generation of alkaloids, phenols, esters, ketones, acids, and heterocyclic compounds, indicating some effect may exist between cigar tobacco and glycerol.
研究领域:
能源科学
·
化学工程
·
烟草科学
✓ 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
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
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2023
·
IF 6
Shi-yu Feng,Kai Li,Ting Huang,Cheng-bo Zhang,An-qing Zheng,Yan-qin Huang,Shi-guan Yang,Qiang Lu
This study presented a novel method for the simultaneous generation of monophenol chemicals and carbon-based CO 2 adsorbent from polycarbonate (PC) by using salt solution-enhanced pyrolysis. The regulatory functions of several factors on the production of 4-isopropenylphenol (IPP) and phenol were investigated using a laboratory-scale pyrolysis reactor , including salt solution type (neutral, acidic, and alkaline), solution concentration, and pyrolysis temperature. The results revealed that the Na 2 CO 3 solution exhibited the best ability to enhance the preparation of IPP and phenol. At Na 2 CO 3 concentration of 1 mol/L and pyrolysis temperature of 600 °C, the optimum yields of IPP and phenol reached 28.83 wt% and 33.77 wt%, respectively. The pyrolysis char (PCSC) obtained under this condition exhibited good CO 2 adsorption behavior with a maximum adsorption capacity of 1.75 mmol/g at 30 °C because of its well-formed porous structure and copious oxygen-containing functional groups.
研究领域:
化学工程
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2021
·
IF 9.642
Jiajun Yu,Bingbing Luo,Yihan Wang,Siyu Wang,Kai Wu,Chao Liu,Sheng Chu,Huiyan Zhang
In this study, a simple and rapid method was proposed to synthesize orthorhombic α-Mo 2 C as catalyst for lignin catalytic pyrolysis. Biomass in-situ pyrolysis products were used as the carbon source and supporter, the carbonization of Mo precursor was realized under rapid heating. Experimental results show that Pine-Mo 2 C catalyst can achieve lignin pyrolysis vapor bond breaking and deoxidation under normal pressure, and the yield of monocyclic aromatic hydrocarbons is 13.26 wt%, of which aromatic hydrocarbons with side chain account for 74%. The side chain aliphatic hydrocarbons of lignin are effectively retained, and hydrogen consumption is minimized. The characterization of catalyst and experiments of guaiacol, 2-phenoxy-1-phenylethanol and 4,4′-biphenol shows that efficient deoxidation is due to targeted attack of catalyst on C-O. Therefore, Pine-Mo 2 C shows excellent activity in promoting direct bond breaking deoxidation of lignin.
研究领域:
化学工程
·
催化
·
可再生能源
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2022
·
IF 8.129
Lei Wang,Mengdi Liang,Yang Fang,Jun Yin,Jungang Jiang,Yifan Zhang,Haiping Yang
Understanding the pyrolysis mechanism of native lignin is essential for improving the conversion efficiency of fast pyrolysis technology. However, due to the complex and various nature of lignin interunit linkages, the pyrolysis mechanism of lignin has not been clearly revealed so far, especially for native lignin. In this work, two types of guaiacyl-dehydrogenation polymers (G-DHPs) were synthesized using two different methods in vitro , namely endwise polymerization (G-DHPs-endwise) and bulk polymerization (G-DHPs-bulk), which were used as native lignin models. The chemical structures of the synthesized G-DHPs along with natural G-lignin ( i.e., milled wood lignin, MWL) were analyzed by using 2D HSQC NMR, and their pyrolysis characteristics were investigated by using a fixed bed reactor . In comparison with G-DHPs-bulk, G-DHPs-endwise had more similar structure and pyrolysis characteristics with that of MWL, which suggested that G-DHPs-endwise was a more suitable model for G-type lignin. Further mechanical study revealed that the pyrolysis of G-DHPs-endwise underwent an end-breaking pathway, by which the branched carbon of the coniferyl alcohol structure ends were cleaved at the early stage to depolymerize into guaiacol . This study can thus enhance the understanding of the thermal depolymerization of native lignin and provide the evidence for revealing pyrolysis mechanism.
研究领域:
化学工程
·
生物质能
·
分析化学
✓ 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）