INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Huiqi Jin,Haiqiang Shi,Wenchao Jia,Yanning Sun,Xueru Sheng,Yanzhu Guo,Haiming Li,Haidong Sun
The molecular weight is one of the most important factors influencing the utilization of industrial lignin obtained from chemical pulping process. In this paper, a facile operative green solvent system was successfully developed for molecular weight-controllable fractionation of industrial alkali lignin (IAL) at room temperature. The results showed that through adjusting the ratio of water, ethanol and γ-Valerolactone (GVL), the industrial lignin was fractionated into six levels with molecular weight stepwise controllable from low to high. The fractionation is a physical process according to FTIR and 2D-HSQC NMR analysis, and the chemical structure of lignin has not changed. Additionally, the polydispersity of fractionated lignin with higher molecular weight tends to be narrower. The content of hydroxyl and carboxyl group is higher for the fractionated lignin with lower molecular weight, which would be beneficial for the chemical reactivity in the down-stream application.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2019
·
IF 4.191
Qilin Zhang,Chao Wang,Jianzhen Mao,Shri Ramaswamy,Xueming Zhang,Feng Xu
A bifunctional solid organocatalyst, sulfamic acid, was evaluated to produce furfural from xylose and different biomass in an environmentally friendly system comprising Gamma-Valerolactone (GVL) and water. The highest yield (70.19%) of furfural was achieved in a 90% solution of GVL in water containing 10 mol% of sulfamic acid at 190 °C for 15 min from xylose. The potential mechanism of sulfamic acid efficiently catalyzing xylose isomerization and dehydration is presented for the first time. It is hypothesized that another sulfamic acid form, the zwitterionic unit (H 3 N + SO 3 − ) is crucial in efficiently catalyzing isomerization reaction due to its electron-rich sulfonate being superior in attacking the hydrogen atom on C1 leading to the xylose tautomerization to xylulose, a shorter route to furfural, and finally, the NH 2 SO 3 H with strong acidity also promotes the xylulose dehydration to furfural. The above system was evaluated using various biomass species including corncob, Miscanthus × giganteus , the hull and shell of Camellia oleifera (tea) fruit and Aleurites fordii HemsL. (tung) fruit. Almost all these biomass showed excellent furfural yields (over 70%), with tung shell providing the best yield of 92.19% at 200 °C and reaction time of 30 min.
研究领域:
化学工程
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催化
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生物化工
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可再生能源
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2019
·Vol. 22
·期 2
·532-539
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IF 9.405
Qixuan Lin,Shouwei Liao,Libo Li,Weiying Li,Fengxia Yue,Feng Peng,Junli Ren
In this study, experiments and molecular dynamics simulations were combined to get insights into the role of solvent during the process of xylose conversion under catalyst-free conditions. Solvents used for furfural production were comparatively discussed, including traditional and emerging biomass-derived solvents – water, dimethyl sulfoxide (DMSO), dimethyl formamide (DMF), isopropanol (ISO), γ-butyrolactone (GBL) and γ-valerolactone (GVL). The degradation behavior of solvents, the solubility and α/β ratio of xylose, the distribution of the solvent around xylose/furfural and the hydrogen bonding between them were also studied. The results showed that in pure solvents, the different hydrogen bonding between xylose and the solvent resulted in different products. Water was a favourable solvent for xylose to form furfural among these pure solvents because less formic acid was produced from xylose in water under catalyst-free conditions. Furfural could be produced in mixed solvents if there was more water around xylose, which was similar to the case in pure water. Otherwise, the situation in mixed solvents was similar to that in the corresponding pure organic solvents. GBL and GVL, as green solvents, had weaker affinities with xylose than DMSO, DMF and ISO, but were intensively attracted by furfural, thus they could provide protective shells for furfural, which played a positive role during the production of furfural. The highest furfural yield of 46.4% was achieved in GBL–H2O at 180 °C – 150 min in the absence of catalysts.
研究领域:
化学工程
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生物质转化
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分子动力学模拟
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绿色化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2017
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IF 3.181
Luxin Zhang,Guoyun Xi,Kun Yu,Han Yu,Xiaochang Wang
With the aim to enhance the efficiency of the furfural production from lignocellulosic biomass, different catalysts, such as montmorillonite, heteropolyacids, silicoaluminophosphates, and modified beta zeolites, were studied for catalysis of the conversion of biomass–derived carbohydrates and raw biomass into furfural in lactone solvents. Interestingly, we obtained atypical results showing that modified beta zeolites convert glucose and cellulose into furfural as the predominant product. Furfural formation from corncob, sugarcane bagasse, xylose/glucose mixtures, and xylan/cellulose mixtures were also studied. Al–beta was found to display high activity for the conversion of corncob and bagasse in γ-valerolactone (GVL), giving furfural yields of up to 51.1% and 40.9% (molar yields based on both cellulose and xylan content), respectively. The catalytic route proposed in this paper showed a great potential for co–converting hemicellulose and cellulose in the furfural production from lignocelluloses.
研究领域:
化学工程
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催化
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生物化工
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Science Advances
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2022
·Vol. 8
·期 40
·
IF 14.957
Xiaofei Zhang,Caoyu Yang,Pengfei An,Chengqian Cui,Yumiao Ma,Haitao Liu,Hui Wang,Xiaoying Yan,Guodong Li,Zhiyong Tang
Numerous efforts are being made toward constructing artificial nanopockets inside heterogeneous catalysts to implement challenging reactions that are difficult to occur on traditional heterogeneous catalysts. Here, the enzyme-mimetic nanopockets are fabricated inside the typical UiO-66 by coordinating zirconium nodes with terephthalate (BDC) ligands and monocarboxylate modulators including formic acid (FC), acetic acid (AC), or trifluoroacetic acid (TFA). When used in transfer hydrogenation of alkyl levulinates with isopropanol toward γ-valerolactone (GVL), these modulators endow zirconium sites with enhanced activity and selectivity and good stability. The catalytic activity of UiO-66FC is ~30 times that of UiO-66, also outperforming the state-of-the-art heterogeneous catalysts. Distinct from general consensus on electron-withdrawing or electron-donating effect on the altered activity of metal centers, this improvement mainly originates from the conformational change of modulators in the nanopocket to assist forming the rate-determining six-membered ring intermediate at zirconium sites, which are stabilized by van der Waals force interactions.
研究领域:
催化
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纳米技术
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）