RENEWABLE ENERGY
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2023
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IF 8.7
Meishan Fan,Jun Li,Zhu Liu,Caiqun Li,Hongdan Zhang,Jun Xie,Yong Chen
As green and effective depolymerization processes, CrCl 3 and CrCl 3 -catalyzed ethanol pretreatment were comprehensively investigated to improve cellulose conversion from pretreated residues in poplar in the present study. The influence of pretreatment temperature on delignification , structural characteristics of lignin, and the yield of glucose and ethanol was comparatively analyzed to emphasize the synergy effect of CrCl 3 and ethanol solvent. Particularly, CrCl 3 -catalyzed ethanol pretreatment at 200 °C resulted in the pretreated substrates with >94% removal of hemicellulose and lignin, consequently reaching 88.88% and 56.11% yields of glucose and ethanol, respectively. Lignin's structural change was observed by Gel permeation chromatography and 2D nuclear magnetic resonance spectroscopy and its relationship with the efficiency of enzymatic hydrolysis and fermentation was determined. Results indicated that the increased pretreatment temperature enhanced the lignin depolymerization with smaller molecular weight , fewer β-O-4 linkages, and higher S/G ratio, especially in CrCl 3 -catalyzed ethanol pretreatment, which was positively associated with poplar cellulose conversion. In addition to offering a comprehensive illustration of the sugar/ethanol generation during CrCl 3 -catalyzed organosolv pretreatment, this work also provided theoretical support for biofuel and biochemical production from poplar.
研究领域:
生物化学
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可再生资源与环境科学
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DOI
高影响因子
FUEL
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2025
·
IF 7.5
Bingying Ni,Xiaoyu Pei,Weihua Chen,Meishan Fan,Jun Xie
As a green and efficient pretreatment method, CrCl 3 -catalyzed ethanol pretreatment was employed to depolymerize poplar at various reaction times (5, 10, 20, 30, 50, and 70 min) and temperatures (160, 170, 180, 190, and 200°C) to effectively remove lignin and hemicellulose, thus improving the subsequent enzymatic saccharification efficiency of cellulose. The maximum lignin and hemicellulose removal yields of 94.51 % and 94.78 %, respectively, were achieved when pretreated at 200°C for 20 min. Furthermore, The CrCl 3 -ethanol pretreatment was found to have low dissolution activation energies (18.03 kJ/mol for lignin and 24.15 kJ/mol for hemicellulose) through pseudo-first-order kinetic modeling with ’potential solubility’ integration, demonstrating an energy-efficient synergistic effect conducive to reaction progression. Finally, combining density functional theory (DFT) from the molecular level clarified that hydrogen bonding and conjugated effect of CrCl 3 –ethanol solution and lignin-hemicellulose co-caused high efficiency separation of lignin and hemicellulose. This study integrated kinetic modeling and quantum chemical analysis to unravel the hydrogen-bond-mediated deconstruction mechanism, significantly advancing sustainable biorefinery strategies for efficient biomass valorization.
研究领域:
生物质转化
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绿色化学
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催化化学
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可再生能源
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分子生物学
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反应动力学
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量子化学计算
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2015
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IF 2.79
Jingying Pan,Jie Fu,Xiuyang Lu
A systematic study on microwave-assisted oxidative degradation of lignin model compounds, such as 2-phenoxy-1-phenylethanol, vanillyl alcohol, and 4-hydroxybenzyl alcohol, was performed by evaluating the catalytic activity of 14 types of metal salts. The acidity of each metal salt solution for the oxidative degradation of 2-phenoxy-1-phenylethanol, vanillyl alcohol, and 4-hydroxybenzyl alcohol under the microwave irradiation and conventional heating conditions was measured and compared. The results showed that CrCl3 and MnCl2 were the most effective for the degradation of the lignin model compounds. The acidity of metal salt is in favor of the catalytic activity for the degradation of 2-phenoxy-1-phenylethanol, vanillyl alcohol, and 4-hydroxybenzyl alcohol, and microwave irradiation is able to accelerate the degradation rate in a large scale. The possible mechanisms for the degradation of 2-phenoxy-1-phenylethanol, vanillyl alcohol, and 4-hydroxybenzyl alcohol are proposed on the basis of the product distributions.
研究领域:
化学工程
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环境科学
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产品关联
DOI
高影响因子
GREEN CHEMISTRY
·
2015
·Vol. 17
·期 8
·4206-4216
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IF 8.02
Jinxia Zhou,Zhi Xia,Tingyu Huang,Peifang Yan,Wenjuan Xu,Zhanwei Xu,Jianji Wang,Z. Conrad Zhang
Increasing the glucose loading in the 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid containing a dissolved CrCl3 catalyst system led to excessive formation of humins and a serious decrease in the 5-hydroxymethylfurfural (5-HMF) yield. A biphasic system containing glycol dimethyl ether (GDE) as the extraction phase, and [BMIM]Cl/CrCl3/glucose in combination with a partitioned amount of GDE and an appropriate amount of water as the reaction phase was found to be highly efficient for the reaction; CrCl3 catalyzed the formation of 5-HMF in 64.5 mol% yield from a very high glucose concentration (80 wt% with respect to the ionic liquid) at 108 °C. This 5-HMF yield in the [BMIM]Cl–GDE–H2O ternary biphasic system nearly doubled that obtained in the single [BMIM]Cl/CrCl3/glucose reaction phase. Importantly, the GDE phase contained about 56% of the generated 5-HMF without detectable contamination by the ionic liquid or carbohydrates. GDE served multiple functions: as a hydrogen-bond acceptor, it exhibited excellent extraction performance for 5-HMF; due to its low boiling point and suitable solubility saturation point in the ionic liquid, a sustained GDE bubbling phenomenon in the ionic liquid phase was observed that promoted the rate of inter-phase mass-transfer of 5-HMF in reactions; and GDE mediated the [BMIM]Cl phase to a reduced viscosity. In addition, an appropriate amount of water in the ternary system promoted the extraction efficiency of 5-HMF and also lowered the viscosity of [BMIM]Cl/glucose. The ionic liquid–organics–water ternary biphasic system has been demonstrated for high 5-HMF productivity and separation efficiency.
研究领域:
化学工程
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生物化学
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2013
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IF 2.853
Fan Yang,Jie Fu,Jing Mo,Xiuyang Lu
The mixed-acid systems of four Lewis acids (FeCl3, CrCl3, ZnCl2, and CuCl2) combining three Brønsted acids (H2SO4, HCl, and H3PO4) were evaluated for the decomposition of glucose to produce levulinic acid (LA). The CrCl3–H3PO4 system had a strong synergic catalytic activity for the decomposition of glucose to LA. The effects of the ratio of CrCl3 and H3PO4 on glucose, fructose, and 5-hydroxymethylfurfural (5-HMF) decompositions were investigated. The mixed-acid system showed the strongest synergic catalytic activity for glucose, fructose, and 5-HMF decompositions when the ratio of CrCl3 in the CrCl3–H3PO4 system was 0.4–0.5. To probe the synergic catalysis mechanism of the CrCl3–H3PO4 system, the synergic catalytic activities of CrCl3–phosphates (KH2PO4, K2HPO4, and K3PO4) systems on glucose decomposition were also evaluated. The possible synergic catalysis mechanisms were proposed. This study provides insights for the synergic catalysis mechanism of hexose conversion to yield LA.
研究领域:
化学工程
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可再生能源
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催化科学
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DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2016
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IF 4.917
Riyang Shu,Qi Zhang,Longlong Ma,Ying Xu,Pengru Chen,Chenguang Wang,Tiejun Wang
The aim of this study is to explore the reaction mediums and conditions for producing high yield of valuable monomers from concentrated sulfuric acid hydrolyzed lignin. The solvent, temperature and time effects on the hydrogenolysis of hydrolyzed lignin were investigated under the catalysis of Pd/C and CrCl 3 . Supercritical methanol exhibits the best depolymerization performance, because of its unique diffusion, dissolution and acid-base properties. Afterwards, the influence of reaction temperature and time on depolymerization, repolymerization and coking during hydrogenolysis was examined in methanol. The high temperature is found to favor the depolymerization, with the β-O-4 linkages cleaved significantly. However, the repolymerization is promoted simultaneously, and a high amount of β-β groups form. These reactions are in constant competition with each other and the repolymerization is preferred at excessive high temperature, producing bulk char residues, that is coking. This study will provide a beneficial reference for the maximization of lignin waste valorization.
研究领域:
化学工程
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生物质转化
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可再生资源利用
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产品关联
DOI
PubMed
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2025
·
IF 1.7
Guo Lirong,Yang Xiaodie,Shao Huijuan,Zhang Xuzhi,Wang Yating,Jiang Tao
We have investigated the effect of different impurities (CO, CO 2 , CS 2 , CH 3 OH, H 2 O, C 4 H 4 S) on the silicon-bridged diphosphine(PNSiP)/CrCl 3 (C 4 H 8 O) 3 /modified methylaluminoxane ethylene tri-/tetramerization system. The results showed that the addition of trace impurities has a certain inhibitory effect on catalytic activity. The influence of impurities on the catalytic activity of the catalyst system was as follows: CO > CO 2 > CS 2 > CH 3 OH > H 2 O > C 4 H 4 S. CO showed the most significant inhibitory effect in reducing activity from 1.75 × 10 6 g/(mol Cr h) to 0.74 × 10 6 g/(mol Cr h) at an addition of 0.2 ppm. Through the analysis of nuclear magnetic resonance (NMR) and ultraviolet–visible spectrophotometry (UV–vis), we found that carbon monoxide mainly inactivates the catalytic system by coordinating with chromium active sites, while methanol and water reduce the catalytic activity by destroying the structure of modified methylaluminoxane. Furthermore, we also proposed a possible reaction path between carbon monoxide and the chromium active center. Graphical abstract
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Riyang Shu,Ying Xu,Longlong Ma,Qi Zhang,Chao Wang,Ying Chen
Many effective methods have been proposed to achieve lignin depolymerization, while controllable product distribution is still hard to realize. Herein, an efficient lignin hydrogenolysis process with controllable product distribution was put forward using Pd/C catalyst cooperated with metal chloride. Results showed that lignin produced a high amount of guaiacols in the presence of ZnCl 2 , while a high amount of phenols in the presence of CrCl 3 . Guaiacylglycerol-β-guaiacyl ether was used as the model compound to carry out the mechanistic investigation. A synergetic catalysis effect between Pd/C and metal chloride was exhibited in this process. And the Lewis acidity was an important factor to determine the product distribution. With the synergetic catalysis of Pd/C and metal chloride, the dissociation energy of β-O-4 bond was reduced significantly, which made the cleavage easier to realize. The phenolic monomer product of guaiacols was produced in the initial stage. Then CrCl 3 catalyst with strong Lewis acidity could further promote the occurrence of demethoxylation and alkylation, converting the guaiacols into phenols. This work figures out the mechanism of product control in the hydrogenolysis process and displays a clear potential for the controllable valorization of lignin.
研究领域:
化学工程
·
催化
·
可再生能源
·
有机化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）