BIORESOURCE TECHNOLOGY
·
2011
·
IF 4.365
Shurong Wang,Xiujuan Guo,Tao Liang,Yan Zhou,Zhongyang Luo
The mechanism of fast pyrolysis of cellulose has been studied by using an analytical pyrolyzer coupled with a gas chromatography–mass spectrometry set-up (Py-GC/MS). The results showed that the main products comprised pyrans such as levoglucosan and levoglucosenone, furans such as furfural and 5-hydroxymethyl furfural, and linear small molecular chemicals such as acetaldehyde and 1-hydroxy-2-propanone. The compositions of products from fast pyrolysis of cellubiose and glucose were similar to that from cellulose, but with higher furan contents and lower pyran contents. Based on the experimental results, density functional theory (DFT) studies were carried out to deduce the pyrolysis mechanism of cellulose. The results showed the formation of 5-hydroxymethyl furfural from d -glucopyranose unit to be easier than the formation of levoglucosan, in agreement with the experimental results. The deduced mechanism of reaction pathways in cellulose pyrolysis provides insight into the pyrolysis behavior of cellulose and allows modification of previously proposed related mechanisms.
研究领域:
化学工程
·
能源科学
·
计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2018
·Vol. 132
·期 3
·1729-1740
·
IF 2.209
Yuan Jiao-jiao,Tu Jun-ling,Xu Yong-jun,Qin Frank G. F.,Li Bing,Wang Cheng-zhang
Olive leaf extract pretreated by enzymolysis was selected for studying the thermal stability at different heating rates by thermogravimetric coupled with infrared spectroscopy (TG–FTIR) and nonisothermal theoretical analysis, and products analysis by pyrolysis–gas chromatography–mass spectrometry (Py–GC–MS). Results revealed that thermal decomposition of ethyl acetate extract from olive leaf extract pretreated by enzymolysis (EAEEH) consisted of two steps and had a lower thermal stability. The nonisothermal decomposition kinetics mechanism of EAEEH was D3 model (three-dimensional diffusion, Jander equation, the first step) and F3 model (chemical reaction, n = 3, the second step). TG–IR showed –CH 3 , –C=C–, –OH, –C–O were continuously accelerated to produce, and evolved gas were CO 2 , water, CO and CH 4 at the end. In addition, it was found that there were mainly polyphenols with phenolic hydroxyl groups in the pyrolysis products by Py–GC–MS, and it was also explained for the thermal stability results. This will provide a theoretical guidance for thermal application of EAEEH in the safe natural food additives, cosmetic and medicine.
研究领域:
食品科学
·
化学工程
·
植物化学
✓ 已验证
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2021
·Vol. 13
·期 13
·11789-11802
·
IF 4.987
Zhang Liqiang,Liu Jiaojiao,Zhang Zexia,Yang Zhengda,Wang Xinwei,Li Dawei,Lin Riyi
Two-step pyrolysis (TSP) of cellulose, hemicellulose, and lignin; the three-component cross-coupling samples; and the acid-washed walnut shell (AWS) were carried out by a pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) to investigate the effects of components and their proportions on the TSP of biomass. The results showed that different components dominated the formation of different products. Cellulose generated more furans and carbohydrates in both the first (S1) and second steps (S2). Hemicellulose achieved higher selectivity of ketones, acids, and alcohols in S1, and higher selectivity of hydrocarbons in S2. Lignin mainly produced phenols in S1, and hydrocarbons and phenols in S2. The increase of holocellulose (hemicellulose and cellulose) improved the contents of aldehydes, ketones, furans, acids, and alcohols but reduced the content of phenols in S1. In S2, more holocellulose increased the contents of aldehydes, ketones, and acids, but decreased the contents of phenols, hydrocarbons, and alcohols. The generation of carbohydrates was strongly inhibited in S1 by hemicellulose and lignin. More cellulose improved the contents of aldehydes, acids, and furans in S1, and increased the content of ketones but reduced the content of acids in S2. Hemicellulose facilitated the generation of hydrocarbons, but inhabited the produce of carbohydrates in S2. The small amount of the low-content components (protein, alkali and alkaline earth metals, etc.) and the connection structure of the components resulted in the significant difference in the pyrolysis reactions and product distribution of AWS and the mixed sample with corresponding component proportion. Therefore, more influence factors, such as the low-content components, the connection structure of the components, and different pyrolysis conditions, should be considered in the near future to investigate the interactions on the two or more components in TSP.
研究领域:
能源与环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2019
·
IF 3.47
Adel Baimoldina,Konstantinos Papadikis,Elena Yu. Konysheva
The feasibility of α-Fe 2 O 3 catalyst addition in the in-situ catalytic fast pyrolysis of Pinewood was considered with the focus on the variation in its shape: nano-sized non-ideal spheres, nanotubes, hollow nano/microtubes, and octadecahedral crystals. Nano-sized spheres strongly promoted the formation of acetaldehyde, something that was also observed for the octadecahedral crystals. The formation of acids was primarily facilitated through the addition of nanotube catalysts and octadecahedral crystals. Newly formed alicyclic ketonic compounds were promoted through the addition of nano-sized spheres, hollow nano/microtubes, and octadecahedral crystals. The latter two catalysts also showed a moderate selectivity in the formation of furfural. All applied catalysts showed loss of activity, though at different degrees, on the formation of lignin derived phenolic compounds, which can be primarily attributed to favoring the formation of char with simultaneous release of CO 2 . All used α-Fe 2 O 3 catalysts with different shapes maintained their original morphology after the rapid heating with the rate of 20 K/ms followed by catalytic fast pyrolysis at 500 °C, indicating that nanomaterials with targeted dimensions can be applied as catalysts in the catalytic fast pyrolysis of biomass to enhance conversion of undesired oxygenated compounds to higher quality bio-oil and valuable chemicals.
研究领域:
催化
·
生物质能源
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2019
·Vol. 9
·期 10
·849
·
IF 3.444
Zeyu Xue,Zhaoping Zhong,Bo Zhang,Chao Xu
To investigate the catalytic pyrolysis performance of complex metal oxide catalysts for biomass, γ-Al2O3was prepared through the precipitation method, and then ZrO2and γ-Al2O3were blended in the proportion of 2:8 using the co-precipitation method. Next, CeO2was loaded on the surface of the catalyst for further modification. The three catalysts, A, ZA and CZA, were obtained. The specific surface and acidity of the catalysts were characterized by nitrogen adsorption–desorption and NH3-Temperature Programmed Desorption (NH3-TPD) respectively. The catalytic pyrolysis performance of catalysts for bamboo residues was investigated by Pyrolysis gas chromatography mass spectrometry (Py-GC/MS). Chromatograms were analyzed for identification of the pyrolysis products and the relative amounts of each component were calculated. Experimental results indicated that catalyst A had a good catalytic activity for the fast pyrolysis of bamboo residues. The addition of ZrO2and CeO2could continuously enhance the acidity of the catalyst and further promote the pyrolysis of macromolecular compounds and deoxidation of oxygen-containing compounds. Finally, catalyst CZA, obtained by compound modification, could not only dramatically reduce the relative content of phenol, acid and aldehyde and other oxygen-containing compounds, but also achieved the maximum hydrocarbon yield of 23.38%. The catalytic performance of catalyst CZA improved significantly compared with catalyst A.Keywords:biomass;pyrolysis;catalytic cracking;Py-GC/MS;complex metal oxides
研究领域:
能源与燃料化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Shiliang Wu,Dekui Shen,Jun Hu,Huiyan Zhang,Rui Xiao
The pyrolytic characteristics of cellulose, cellobiose and glucose were examined by TG-FTIR combined with Py-GC–MS, in order to gain the effect of β -O-4 glycosidic bond on the pyrolysis process. In TG-FTIR analysis, two mass loss peaks were observed for cellobiose and glucose, indicating dehydration in low temperature stage and consequently intensive cracking of glycosidic bond and fragments for cellobiose. The samples were tested in Py-GC–MS at the temperature of 300, 500 and 900 °C according to their mass loss characteristics from TG-FTIR. Formation of furans from cellobiose, which involved the cracking of β -O-4 glycosidic bond, was prominent over other products, compared to that of cellulose and glucose. Four possible chemical pathways for the cleavage of β -O-4 glycosidic bond have been proposed with regard to the formation of furans and anhydrosugars from cellulose. Besides, another two reaction pathways leading to the formation of levoglucosan were also suggested.
研究领域:
生物质化学
·
热化学转化
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2020
·
IF 3.275
Tao Zhou,Hang Xiao,Weifeng Peng,Bo Liang,Yao Liu,Jiangbo Lv,Jianghuai Hu,Ke Zeng,Gang Yang
The pyrolysis behaviors of l -tyrosine-based phthalonitrile(TPN) resin were investigated by thermogravimetric-Fourier transform infrared spectrometry-mass spectrometry (TG-FTIR-MS) and Pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The small molecules produced during pyrolysis process of TPN resin were tracked in real time by TG-FTIR-MS. The larger molecules ( m / z > 40) from fast pyrolysis at 900 °C of the TPN resin using Py-GC/MS were identified. From TG-FTIR-MS and Py-GC/MS results, the production pathways of pyrolysis products such as CO 2 , CO, NH 3 , benzonitrile and phenol were analyzed. The possible pyrolysis mechanism of TPN resin under non-oxidizing gaseous environment was proposed. The results of this study provide the useful information for designing the molecular structure of l -tyrosine-based polymers which possessing high thermal stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Processes
·
2022
·Vol. 10
·期 10
·1970
·
IF 3.352
Xuan Zhou,Hongling Pan,Shuixiang Xie,Guotao Li,Zhicai Du,Xiang Wang,Yan Luo
The aim of this research is to design and synthesize an efficient catalyst to enhance high value-added products, such as aromatic hydrocarbons and phenols, from the catalytic fast pyrolysis (CFP) of different types of forestry and agricultural residues. All three biomasses (rape straw, wheat straw, and bamboo powder) had no aromatic production via thermal pyrolysis alone; however, the aromatic selectivity and monocyclic aromatic selectivity were largely enhanced using ZSM-5, with suitable silica-alumina ratios and Ni loadings. Specifically, for rape straw, the optimum catalyst was 15 wt.% Ni/ZSM-5 (silica-aluminum ratios = 85), and the selectivity of aromatic hydrocarbons was achieved at 39%, of which 71% were monocyclic aromatic hydrocarbons. For wheat straw, the optimum catalyst was 10 wt.% Ni/ZSM-5 (silica-aluminum ratios = 18), and the selectivity of aromatic hydrocarbons was 67%, of which 55% were monocyclic aromatic hydrocarbons. For bamboo powder, the optimum catalyst was 10 wt.% Ni/ZSM-5 (silica-aluminum ratios = 18), and the selectivity of aromatic hydrocarbons was achieved at 21%, of which 80% were monocyclic aromatic hydrocarbons. Meanwhile, biomass types have significant effects on the pyrolyzed product distribution due to their different components. Cellulose and hemicellulose promoted the production of aromatic hydrocarbons, while lignin enhanced the production of phenols. The promotion of phenol by Ni was better and more efficient than that by the molecular sieve.Keywords:catalytic fast pyrolysis;forestry and agricultural residues;Ni/ZSM-5;aromatic hydrocarbons;phenols;Py-GC/MS
研究领域:
能源与环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Kuan Ding,Zhaoping Zhong,Bo Zhang,Jia Wang,Addy Min,Roger Ruan
Pyrolysis of waste tire with HY, HZSM-5 (HZ) and purified attapulgite (PA) catalysts to produce valuable aromatic hydrocarbons has been carried out in a Pyrolyzer- Gas Chromatograph/Mass Spectrum (Py-GC/MS) reactor. Likewise, d -limonene and polybutadiene rubber (BR), which played important roles in the pyrolysis process of waste tire, has also been pyrolyzed in the Py-GC/MS reactor with these catalysts. Based on the product distribution, the catalytic pyrolysis mechanisms of d -limonene were proposed, while those of BR were extended. With these mechanisms, the catalytic pyrolysis characteristics of waste tire could be explained reasonably. Results showed that HY promoted a dramatic increase of aromatics from pyrolysis of d -limonene and BR, leading to the considerable growth of aromatics in the degraded products of waste tire. The shape selectivity of HZ to mono-cyclic aromatics performed effectively in the pyrolysis of BR, yet it exhibited a weak performance in the pyrolysis of d -limonene. As a result, upon the catalytic pyrolysis of waste tire, HZ was inferior to HY in the aromatization ability. However, the selectivity of HZ to BTXE (benzene, toluene, xylene and ethylbenzene) was superior to that of HY. PA performed a weaker catalytic ability in promoting the production of aromatics during the pyrolysis of d -limonene, BR and waste tire.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Science China-Technological Sciences
·
2023
·Vol. 66
·期 8
·2258-2270
·
IF 4.6
Wang Na,Gu An,Lei Yong
Lacquer is the main raw material of lacquerware, while UV-irradiation is an important factor leading to its aging. In order to investigate the aging behavior of urushi lacquer film under UV-irradiation, and to propose parameters that can be used to evaluate its aging degree, the micro-UV/Py-GC/MS system has been applied in the present work to enrich and identify volatile products released by urushi film during aging on the one hand, and to investigate micro-amount and conventional urushi films with different aging degrees on the other hand, in addition, representative historical samples have also been investigated. Volatile products released by urushi film demonstrate that during UV-irradiation, polysaccharides wrapping urushiol polymer would be first degraded to generate furans and alcohols, and then urushiol polymer would undergo photo-oxidation and break of molecular chain, mainly generating oxidation products including aldehydes, organic acids, and ketones, as well as a small number of alkyl benzenes and hydrocarbons. Py-GC/MS analysis of micro-amount urushi films with different aging degrees indicates that UV-irradiation is more destructive to aliphatic chains in urushiol polymer, but it also can accelerate the polymerization of micro-amount urushi film. Py-GC/MS analysis of conventional urushi films indicates that with the increase of aging degree, the total chromatographic peak area ratio of hydrocarbons to benzene derivatives gradually increases, the peak area ratio of 3-pentadecenyl-catechol to 3-pentadecyl-catechol gradually decreases, and the peak area ratio of aging products of urushiol to 3-pentadecyl-catechol gradually increases. The above parameters were further used to evaluate the aging degree of two urushi-contained samples separately collected from the surface and interior of a carved lacquer panel in the Forbidden City, and evaluation results are in accord with the natural aging law and further verify the reliability of the proposed parameters. Research results of the present work can lay a foundation for the in-depth study of the UV-irradiation aging mechanism of urushi.
研究领域:
材料科学
·
文物保护
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2020
·
IF 3.905
Kai Li,Bo Wang,Dana Bolatibieke,Dong-Hong Nan,Zhen-Xi Zhang,Min-Shu Cui,Qiang Lu
Levoglucosenone (LGO) is a valuable chiral synthon and can be produced from pyrolysis of cellulose and biomass. In the present study, Ni-P-MCM-41 catalysts with various P-to-Ni ratios were prepared and employed for selective production of LGO from biomass. Both analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and lab-scale experiments were conducted to explore the effects of several factors on the formation of LGO, including P-to-Ni ratio in Ni-P-MCM-41, catalyst/sample ratio and pyrolysis temperature. The results revealed that all the Ni-P-MCM-41 catalysts, especially the one with a P-to-Ni ratio of 5, exhibited excellent catalytic capability and selectivity for LGO production. For Py-GC/MS, the maximal LGO yields of 27.34 wt% and 14.30 wt% were achieved from cellulose and pine at 350 °C with catalyst/cellulose ratio of 3 and catalyst/pine ratio of 2, respectively. While in lab-scale experiments, the highest LGO yields from cellulose and pine were 21.37 wt% and 10.71 wt%, with the corresponding selectivity of 78.31% and 53.75%, respectively. The Ni-P-MCM-41 catalyst possessed much better catalytic efficiency on the LGO production than previously reported catalysts, including H 2 SO 4 , H 3 PO 4 , solid superacid, solid phosphoric acid and activated carbon.
研究领域:
化学工程
·
可再生能源
·
催化
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Jun Zhang,Chengyu Li,Jing Gu,Haoran Yuan,Yong Chen
This study aimed to investigate the co-pyrolysis characteristics of strong-acid cation exchange resin (Amberlyst-15, denoted as A15) and cellulose (CE), in which the existing synergistic interaction effects were uncovered. Crucial variables including pyrolytic temperature, A15-to-CE mass ratio and heating rate were taken into consideration. The levoglucosenone (LGO) production from CE and inorganic sulfur-containing species release from functional sulfonic acid groups of A15 were enhanced in a temperature range of below 400 °C. In this regard, the LGO yield achieved approximately 7 wt% at 300 °C with A15-to-CE mass ratio of 1:1. Relatively, elevating the temperature and heating rate accelerated the A15 self-decomposition and small molecule fragments restructuring to give much more monocyclic and polycyclic aromatics. Noticeably, organic sulfur-containing compounds also were produced in an unignorable amount of 8.2% under preset conditions of pyrolytic temperature of 700 °C and heating rate of 20,000 °C/s. The plausible pathway for the co-pyrolysis transformation of A15 and CE was also proposed on the basis of experimental results. The present work will provide a probable and feasible strategy for the high-value utilization of biomass and waste ion-exchange resins, particularly in the aspect of the generation of certain chemicals.
研究领域:
能源与燃料
·
环境科学
·
生物质转化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）