PROCESS BIOCHEMISTRY
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2019
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IF 2.883
Xiaohui Di,Yu Zhang,Junying Fu,Qiang Yu,Zhongming Wang,Zhenhong Yuan
High value-added utilization of biomass-based platform chemicals has attracted increasing attention in recent years. The present study addresses the upgrading of levulinic acid (LA), an important biomass-based platform chemical, to methyl levulinate via a green and efficient enzymatic approach. Various lipases were assessed, with Novozym ® 435 displaying the best results for the esterification of LA. Subsequently, the effect of reaction medium on Novozym ® 435 catalyzed esterification was also studied. Compared with other reaction media, 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF 6 ]) showed the greatest enhancement in yield by suppressing hydrolysis activity. The catalysts reusability was also improved by protection from [bmim][PF 6 ] with 43.2% activity remained after 5 cycles, compared to that of 19.1% in 2-Me THF. Reaction temperature exerted an unusual double-peak relationship over methyl levulinate yield because Novozym ® 435 can simultaneously catalyze the esterification of LA and hydrolysis of methyl levulinate, each of which has a different optimal reaction temperature: ca. 30 °C and ca. 40 °C, respectively. When the molar ratio of LA/methanol, and the volume ratio of methanol/[bmim][PF 6 ] were 1:5 and 1:3, respectively, methyl levulinate was obtained in 93% yield at 30 °C after 24 h with 10 mg/mL catalytic loading.
研究领域:
生物化学
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绿色化学
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DOI
高影响因子
Biomass Conversion and Biorefinery
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2021
·Vol. 13
·期 4
·2933-2946
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IF 4.987
Zhao Sibo,Wang Zihua,Chang Chun,Li Pan,Xu Guizhuan,Pang Shusheng
A two-stage alcoholysis was developed for improved conversion of furfural residue (FR) into levulinic acid (LA) and methyl levulinate (ML). Mixed acids including 0.01 M of H 2 SO 4 and Al 2 (SO 4 ) 3 and methanol/water (50/50 v/v%) were identified as the suitable catalyst and reaction medium. The optimum alcoholysis conditions were 198 °C and 1.5 h for the 1st stage and then 163 °C and 1.3 h for the 2nd stage, and the maximum total yield of LA and ML can reach 25.64%. The reaction kinetics and possible conversion pathways for ML and LA production were proposed. On the basis, HCOOH/H 2 O 2 pretreatment was screened for the pretreatment of FR, which increased the cellulose content of FR from 40.01 to 71.91%. The maximum total yield of LA and ML from pretreated FR was 44.96% under the optimum conditions of 195 °C and 1.9 h for the 1st stage and then 166 °C and 1.1 h for the 2nd stage, which was 16.09% higher than that of isothermal alcoholysis. The reusability tests showed that the Al 2 (SO 4 ) 3 was stable and can be reused at least 5 times. This study developed a new method for high-value utilization of FR and cleaner production of LA and ML.
研究领域:
化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2018
·Vol. 94
·期 1
·167-177
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IF 2.587
Xuejuan Cao,Junnan Wei,Huai Liu,Xinyue Lv,Xing Tang,Xianhai Zeng,Yong Sun,Tingzhou Lei,Shijie Liu,Lu Lin
BACKGROUND γ-Valerolactone (GVL) is a versatile biomass-derived platform molecule that could serve as a building block to produce chemicals, materials and fuels, but the production of GVL from biomass via a cost-competitive method is challenging. In this contribution, a robust Cu─Mg oxide was prepared as an efficient bifunctional catalyst for both H 2 production by MeOH reforming and hydrogenation of methyl levulinate (ML) to GVL in MeOH medium. RESULTS Cu 0.87 Mg 0.13 O x prepared by a urea hydrolysis method offered a GVL yield up to 90.6% at 220°C in 4 h without external hydrogen. This catalyst could be reused for at least seven consecutive cycles without loss of its activity. Notably, Cu 0.87 Mg 0.13 O x also provided nearly 70% GVL yield in methanolysis products of cellulose in the presence of humins. Characterization of the catalyst indicates that the incorporation of MgO greatly facilitates the stabilization of Cu + species that possess a better catalytic performance in ML hydrogenation compared with metallic Cu. CONCLUSION This robust Cu 0.87 Mg 0.13 O x could greatly contribute to develop a highly facile and desirable two-step strategy for GVL production from cellulose, through the integration of ML production by methanolysis of cellulose, H 2 formation by MeOH reforming and ML hydrogenation in MeOH medium. © 2018 Society of Chemical Industry
研究领域:
化学工程
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可再生资源化学
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DOI
高影响因子
RENEWABLE ENERGY
·
2020
·
IF 6.274
Han Chen,Qiong Xu,Du Zhang,Wenzhu Liu,Xianxiang Liu,Dulin Yin
A series of mesoporous nickel catalysts with different molar ratios of citric acid and nickel nitrate were synthesized via a simple two-step method by solid-state grinding and in-situ reduction; these catalysts were further employed for the catalytic transfer hydrogenation of levulinate esters to γ-valerolactone (GVL) with 2-propanol as the hydrogen donor. The effects of C 6 H 8 O 7 /Ni molar ratios , catalyst dosage, reaction temperature and time on the catalytic performance were investigated. An excellent GVL selectivity of 99.1% and an ethyl levulinate (EL) conversion of 100% could be achieved at 180 °C in 6 h over Ni-1.0 catalyst with a 1.0:1 M ratio of C 6 H 8 O 7 /Ni. The characterization results showed that the Ni-1.0 catalyst was composed of mesoporous metallic Ni bulk and a surface Ni–NiO composite, and the acid sites of NiO played a synergistic catalytic role in producing GVL from EL. The superior mesoporous structure and large surface area of Ni-1.0 increased the atomic utilization rate of nickel metallic active centers. Moreover, Ni-1.0 catalyst could be easily separated and reused ten times, with an EL conversion above 95% remaining in each recycle. This work provids a highly efficient and environmentally friendly catalytic procedure for the conversion of biomass into GVL, a fuel additive compound.
研究领域:
化学工程
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可再生资源与环境科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2018
·
IF 4.521
Zhenzhen Lin,Mengting Luo,Yindi Zhang,Xiaoxue Wu,Yanghe Fu,Fumin Zhang,Weidong Zhu
Heterogeneous catalytic conversion of biomass-derived methyl levulinate (ML) to γ-valerolactone (GVL) is highly attractive as a sustainable route to mitigating the dependence on nonrenewable fossil resources. However, this route is limited by its low selectivity toward GVL and severe reaction conditions. Here, we present a synergistic catalytic process that offers exclusive GVL selectivity with complete ML conversion under mild conditions (80 °C, 0.5 MPa of H 2 pressure). This is achieved over a dual-functionalized catalyst of Ru nanoparticles (Ru-NPs) and Brønsted acid SO 3 H groups in a Cr-based metal-organic framework (MIL-101). The Ru-NPs served as metal sites for the hydrogenation of ML to methyl-3-hydroxyvalerate (MHV) and the acidic SO 3 H moieties promoted the cyclization of MHV to generate GVL via lactonization. In contrast, GVL production was significantly suppressed over the physically mixed congener (2.0 wt% Ru/MIL-101 + MIL-101-SO 3 H). This result demonstrates an unrivalled advantage of the dual integration of metal/acid sites in a single MOF crystal, and the relative amount of sulfonic acid groups in the catalyst can exert significant influence on the overall catalytic performances. The activation energies for the hydrogenation and lactonization steps with the developed catalyst were 29.5 and 42.1 kJ/mol, respectively, which are much lower than those observed with the traditional 5.0 wt% Ru/AC catalyst.
研究领域:
化学工程
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催化科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
·
IF 6.216
Hao Chen,Houhang Ruan,Xilei Lu,Jie Fu,Timothy Langrish,Xiuyang Lu
In the present study, an economic and environmentally friendly bi-functional catalyst, Zr-SBA-15, has been prepared to develop a single-step process for synthesis of methyl levulinate (MLA) directly from furfural (FAL) in near-critical methanol without added H 2 . The presence of Zr in SBA-15, the structure of the Zr-SBA-15 catalyst, and its physical properties have been determined by X-ray diffraction (XRD), N 2 adsorption and desorption (N 2 -BET) and transmission electron microscopy (TEM). The Zr-SBA-15 catalyst has high activity for the production of MLA and good reusability. A possible reaction pathway containing two possible reaction pathways during this single-step synthesis of MLA has been proposed: the FAL has been transformed to β-Methoxy-2-furanethanol (MFE) and 2-Furfuryl methyl ether first, which then have been converted to MLA, and the conversion of FAL to MFE has been much easier and faster than that to 2-FME, which may be the major reaction pathway. The SBA-15 has given high activity for the conversion of FAL to MFE, and the incorporation of Zr has converted the MFE to MLA efficiently. The reaction of FAL to MFE to MLA has been found to be the dominant reaction. Finally, the catalyst has shown good reusability for at least five times without any reduction in the catalytic activity.
研究领域:
催化化学
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可再生化学
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产品关联
DOI
高影响因子
BIORESOURCE TECHNOLOGY
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2021
·
IF 9.642
Wenran Gao,Gang Wu,Xun Zhu,Muhammad Asif Akhtar,Guiying Lin,Xun Hu,Yong Huang,Shu Zhang,Hong Zhang
The conversion of cellulose to platform chemicals has attracted much attention because of its renewability. This work proposed an earth-abundant cobalt disulfide as a heterogeneous catalyst for methyl levulinate production from cellulose. The highest yield of methyl levulinate reached 61 mol% under the tested conditions of 200 °C, 2 MPa initial pressure, 0.45 catalyst/cellulose mass ratio, and 3 h reaction time. The XRD and TEM analyses demonstrated the crystal facet (111) of cobalt disulfide as a robust active site, which was in good agreement with the highest acidity of the crystal facet (111) calculated by the work functions. The XPS characterization showed that the main chemical valence of cobalt disulfide responsible for the methyl levulinate production was the surface Co 2+ species. This study is valuable for the development of a recoverable catalyst for the cellulose to methyl levulinate process.
研究领域:
化学工程
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催化
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可再生能源
✓ 已验证
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2018
·Vol. 2
·期 5
·1035-1047
·
IF 0
Junfeng Feng,Jianchun Jiang,Chung-yun Hse,Zhongzhi Yang,Kui Wang,Jun Ye,Junming Xu
Selective catalytic conversion of biomass waste for producing methyl levulinate (MLA) via directional microwave-assisted liquefaction was investigated. The goal of the study was to develop a directional liquefaction process using dielectric heating with microwave energy. The methanolysis of biomass into methyl levulinate was studied in the presence of several acid catalysts. The C6 sugar substrates in biomass were successfully converted into methyl levulinate under the optimized conditions (180 °C, 40 min) with a yield of 29.39 wt%. 5-Hydroxymethyl furfural, glucose, fructose, cellobiose, corn starch, and microcrystalline cellulose were selected as models for directional microwave-assisted liquefaction. Therefore, the possible reaction pathway of biomass to methyl levulinate could be investigated. The selective catalytic conversion of biomass was found to be highly efficient for the generation of MLA (reaching a maximum yield of approximately 30 wt%), higher than the levulinic acid yield (14 wt%) in aqueous solution under the same reaction conditions. The results suggested that directional microwave-assisted liquefaction is an effective method that can produce a high value-added fuel additive (methyl levulinate) from lignocellulosic biomass under designated reaction processes.
研究领域:
能源与环境科学
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化学工程
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生物质能
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产品关联
DOI
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
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2021
·Vol. 102
·期 7
·2826-2834
·
IF 3.639
Sibo Zhao,Xuezheng Huang,Zhenli Yan,Chun Chang,Guizhuan Xu,Chaojun Du,Youzhou Jiao,Zhiyong Chen
BACKGROUND Environmental concerns and the diminishing availability of unrenewable resources have spurred research into the use of agricultural waste as a feedstock for industrial applications. Efficient conversion of wheat straw into biobased chemicals is an important way to realize the potential value of renewable agricultural biomass. This study investigated one-pot conversion of wheat straw into two notable platform chemicals, levulinic acid (LA) and methyl levulinate (ML). RESULTS A mixed acid catalyst system, including 1% H 2 SO 4 and 0.015 mol L –1 Al 2 (SO 4 ) 3 , was an efficient catalyst for the conversion of wheat straw due to the combination of Brønsted acid and Lewis acid. A ratio of wheat straw to methanol of 5 g/50 mL was identified as the preferred solid/liquid ratio, and a methanol/H 2 O medium with 25% water content aided the simultaneous production of LA and ML from wheat straw. Under optimum conditions, the maximum total yield of LA and ML reached 23.01% at 220 °C and 3 h. The kinetics of biobased chemical formation and the reaction pathways in methanol/water were investigated. CONCLUSION The presence of water in the methanol/H 2 O medium affected the distribution of products and promoted hydrolysis reactions. The methanol/H 2 O medium not only inhibited the side reactions but also promoted the degradation of wheat straw and increased the total yield of LA and ML. This study provides a feasible method for the conversion of wheat straw to prepare biobased chemicals. © 2021 Society of Chemical Industry.
研究领域:
生物化学
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可再生资源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Kai Sun,Yuewen Shao,Cong Ming,Mengjiao Fan,Huailin Fan,Lijun Zhang,Shu Zhang,Yi Wang,Guozhu Chen,Xun Hu
Impregnation is a traditional method for preparing heterogeneous catalysts, which typically includes impregnation, calcination and reduction steps. In this study, catalyst preparation was combined with its use in catalytic hydrogenation for avoiding ex-situ catalyst-synthesis. Specifically, Cu/MgO were prepared by simply mixing CuSO 4 , MgO and the reactant to be hydrogenated such as levulinic acid (LA) or ethyl levulinate (EL) in ethanol with hydrogen. Heating of the mixture to 160 °C could obtain both synthesized Cu/MgO and hydrogenation product of gamma-valerolactone (GVL) (highest yield: 99.9%). The formation of Cu/MgO catalyst proceeded via the steps of fixing Cu 2+ by reacting with the basic sites of MgO to form Cu(OH) 2 . The metastable Cu(OH) 2 decomposed to form CuO that was reduced to Cu for catalyzing conversion of LA/EL to GVL. Such a method is very simple and applicable to prepare varied types of Cu-based catalyst by changing copper salts and supports of varied alkalinity.
研究领域:
催化
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化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
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2022
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IF 13.7
Anon Bunrit,Teera Butburee,Meijiang Liu,Zhipeng Huang,Keerati Meeporn,Chaiyasit Phawa,Jian Zhang,Sanchai Kuboon,Huifang Liu,Kajornsak Faungnawakij,Feng Wang
Herein, we developed photo–thermo-dual catalytic strategies for the production of γ-valerolactone (GVL) from levulinic acid (LA) and its ester using platinum-loaded TiO2 as a dual-functional catalyst. Both catalytic systems were evaluated under mild reaction conditions. In the photocatalysis system, a base plays crucial roles in the conversion of LA and EL to GVL. The control experiments reveal that plausible mechanistic pathways of both systems proceed via the hydrogenation of the ketone group of LA to the corresponding alcohol as a major intermediate followed by a subsequent cyclization step to GVL. This dual-functional catalyst provides alternative strategies for the conversion of LA and its ester into GVL, which could pave the way for biomass utilization in a more effective and practical manner.
研究领域:
催化
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生物质转化
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化学工程
·
可持续化学
✓ 已验证
DOI
高影响因子
BIOMASS & BIOENERGY
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2025
·
IF 5.8
Chun Chang,Xin Liu,Shuo Zang,Kai Fu,Zhen Ma,Xiaoyang Zheng,Huijuan Tian,Zhining Li
Xylose residue (XR), a waste product from the xylose industry, is currently primarily used for incineration, animal feed, and cultivation substrates, representing a significant waste of resources. Due to its rich cellulose content, this study demonstrates the valorization of XR into methyl/ethyl levulinate (ML/EL) under high-solid conditions catalyzed by sulfate, through an integrated approach combining experimental and DFT investigations. Under the same optimized conditions (catalyst loading: 6 g/200 mL, 180 °C, 2 h), an increase in the solid content of XR from 15 % to 30 % in methanol, catalyzed by CuSO 4 , enhanced the ML concentration by 58 % (46.73 → 74.06 g/L), though at the expense of a 20 % yield reduction (24.89 → 19.84 wt%). Analogous trends were observed in ethanol systems catalyzed by Al 2 (SO 4 ) 3 under identical conditions (EL: concentration +60 % (26.0 → 41.59 g/L), yield −19 % (22.96 → 18.64 wt%)). DFT simulations revealed that Brønsted-Lewis acid synergy (e.g., Cu(CH 3 OH) 2 + , Al(CH 3 OH) 4 3+ , and Fe(CH 3 OH) 3 3+ ) governed catalytic performance. The Brønsted-to-Lewis acidity hierarchy (Al 3+ > Fe 3+ > Cu 2+ ) correlated with metal electronegativity but was predominantly modulated by ligand electron transfer. Fukui function analysis highlighted distinct electronic behaviors of H + and Cu 2+ , enabling cooperative catalysis that shifted the rate-limiting step from initial dehydration (39.87 and 39.13 kcal/mol) to glucoside-fructoside isomerization (33.87 and 35.87 kcal/mol). These insights underscore the superiority of bifunctional catalysts in reducing energy barriers and optimizing reaction pathways. By integrating process intensification with acid-site engineering, this work establishes a strategy to reconcile yield-concentration trade-offs in high-solid biomass conversion, offering a scalable route for sustainable levulinate production.
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产品关联
DOI
高影响因子
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