BIORESOURCE TECHNOLOGY
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2012
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IF 4.98
Chun Chang,Guizhuan Xu,Xiaoxian Jiang
The production of ethyl levulinate from wheat straw by direct conversion in ethanol media was investigated. Response surface methodology (RSM) was applied to optimize the effects of processing parameters, and the regression analysis was performed on the data obtained. A close agreement between the experimental results and the model predictions was achieved. The optimal conditions for ethyl levulinate production from wheat straw were acid concentration 2.5%, reaction temperature 183 °C, mass ratio of liquid to solid 19.8 and reaction time 36 min. Under the optimum conditions, the yield of ethyl levulinate 17.91% was obtained, representing a theoretical yield of 51.0%. The results suggest that wheat straw can be used as potential raw materials for the production of ethyl levulinate by direct conversion in ethanol media.
研究领域:
生物化学
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可再生资源利用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2017
·
IF 4.357
Jie Liu,Xue-Qian Wang,Bei-Bei Yang,Chun-Ling Liu,Chun-Li Xu,Wen-Sheng Dong
Tin-exchanged montmorillonite catalysts were prepared by an ion exchange method and examined as solid acid catalysts . The synthesized catalysts were characterized by X-ray fluorescence spectroscopy, inductively coupled plasma optical emission spectroscopy , N 2 adsorption–desorption analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, NH 3 temperature-programmed desorption analysis, and pyridine adsorption Fourier transform infrared spectroscopy. Subsequently, the catalysts were examined for use in the conversion of glucose into methyl levulinate in methanol. A high yield of methyl levulinate of 59.7% was obtained upon conversion of 0.3 g glucose in 24 g methanol over 0.15 g catalyst at 220 °C under 2 MPa N 2 for 6 h. The recyclability of the catalyst was also examined, and the conversions of glucose and methanol remained mostly unchanged under repeated usage of the catalyst in five catalytic runs; in contrast, the yield of methyl levulinate decreased slightly. The excellent catalytic performance of the tin-exchanged montmorillonite catalyst was attributed to a combination of the presence of a large amount of acidic sites and balanced amounts of Lewis and Brønsted acid sites on the catalyst.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 17
·9152-9160
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IF 2.936
Youliang Cen,Shanhui Zhu,Jing Guo,Jiachun Chai,Weiyong Jiao,Jianguo Wang,Weibin Fan
A highly active and selective cobalt catalyst was developed for the hydrogenation of biomass-derived ethyl levulinate (EL) to γ-valerolactone (GVL), ethyl 4-hydroxypentanoate (EHP), 1,4-pentanediol (1,4-PDO) and 2-methyltetrahydrofuran (2-MTHF), which are considered to be value-added chemicals and important biofuels. The effects of reaction time, reaction temperature, catalyst amount and solvent on its catalytic performance were investigated. In addition, the reaction pathway was studied as well. It was found that the selectivity of GVL, 1,4-PDO and 2-MTHF on Co/ZrO2 can be easily tuned by changing reaction conditions, and can reach as high as 94%, 78% and 77%, respectively. The product selectivity is also significantly affected by the catalyst support. With SBA-15 as the support, the selectivity of EHP can reach 90%. Moreover, Co/ZrO2 gave an extraordinarily high GVL productivity of 1.50 mol gmetal−1 h−1 and displayed excellent stability and reusability. Interestingly, coke has a positive effect on the enhancement of GVL yield. AL dimers and trimers were identified as the coke species in the hydrogenation of EL. As far as we know, this is the first work conducting the flexible transformation of EL on cobalt catalysts.
研究领域:
催化化学
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可再生资源化学
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能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
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2019
·
IF 2.584
Chen Liang,Yan Wang,Yangdong Hu,Lianying Wu,Weitao Zhang
Butyl levulinate (BL) is a versatile chemical utilized widely in food and chemical industries, the production of which by using cellulose in biomass resources is of great significance to its sustainable development. Traditional synthesis processes for n-butyl levulinate are confronted with various problems such as high cost of raw materials, difficulty in separating products, etc. In this paper, a novel process for the preparation of BL from cellulose is proposed. The process is composed of five main unit operations including fed-batch hydrolysis, decolorization, extraction, esterification and purification. A 171.63 g/L concentration of the intermediate levulinic acid was obtained at the fifth feeding through the fed-batch hydrolysis process. The resin-activated carbon secondary decolorization method was adopted to remove the soluble humin byproducts with an accumulative decolorization rate of 89%. In the extraction process, the product BL was chosen as the extractant to avoid the introduction of new impurities. After purification, the purity of the final product BL reaches up to 98 wt %. The proposed technique allows for cost-effective and eco-friendly production of BL from biomass resources.
研究领域:
生物化学工程
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可再生资源利用
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
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2021
·Vol. 11
·期 15
·5062-5076
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IF 6.119
Na Ji,Xinyong Diao,Zhihao Yu,Zhenyu Liu,Sinan Jiang,Xuebin Lu,Chunfeng Song,Qingling Liu,Degang Ma,Caixia Liu
The hydrogenation of levulinate esters to γ-valerolactone (GVL) is an important step in the transformation of biomass into biofuels. It is attractive to develop new efficient systems for the catalytic transfer hydrogenation (CTH) of levulinate esters to value-added GVL. In this work, a series of MoS2-based supported catalysts were prepared via an impregnation method for the CTH of biomass-derived ethyl levulinate (EL) to GVL. By comprehensive characterization and catalytic measurements, we found that the CTH activity of EL to GVL is closely related to the MoS2 morphology and acid distribution on the support. Among the catalysts with different supports, the AC support with abundant Lewis acid sites and large surface area facilitated the high dispersion of low stacked MoS2 slabs, and the MoS2-acid synergistic catalysis contributed to the superior activity and selectivity. The conversion of EL and the selectivity of GVL reached 97.2% and 91.2% under optimized conditions over the MoS2/AC catalyst (230 °C, 1 MPa H2, 1.5 h), respectively. We also conducted reaction kinetic experiments to reveal the relationship between the active site of the MoS2/AC catalyst and its catalytic performance, and the plausible reaction pathway and mechanism over MoS2/AC was proposed. The catalytic performance gradually declined during recycling tests due to the oxidation of MoS2 and can be easily recovered by resulfuration.
研究领域:
化学工程
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生物质能
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
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2017
·Vol. 12
·期 4
·527-535
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IF 0.836
Guizhuan Xu,Binglin Chen,Zhangbin Zheng,Kai Li,Hongge Tao
5-Ethoxymethylfurfural (EMF) and ethyl levulinate (EL) have been considered as the new promising biofuels. A comparative study was conducted for the direct conversion of carbohydrates into EMF and EL in different medium containing ethanol. The distribution and formation kinetics of EL, EMF, 5-hydroxymethylfurfural (HMF) and levulinic acid (LA) in pure ethanol and ethanol/organic solvent medium were compared, and the results showed that the addition of n-hexane can improve the accumulation of EMF. When the volume ratio of ethanol to n-hexane was 6:4, 66.29% of EMF yield can be obtained from fructose at 120°C and 180 min. The total yield of the EMF and EL can reach to 83.71%, increased by 5.73% compared with that in pure ethanol medium. Moreover, water addition can suppress the etherification of HMF to EMF and promote the rehydration of HMF to LA in the process. On the basis, a putative reaction pathway for the conversion of carbohydrates in ethanol/n-hexane medium was proposed. © 2017 Curtin University of Technology and John Wiley & Sons, Ltd.
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
RSC Advances
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2016
·Vol. 6
·期 76
·72744-72749
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IF 3.289
Fei Xia,Zhongtian Du,Junxia Liu,Yangyang Ma,Jie Xu
Recently, obtaining value-added chemicals from biomass resources has attracted considerable attention. Levulinic acid is one of the most important biomass platform compounds, which could be obtained from carbohydrate biomass. In this work, levulinic acid was selectively converted into C4 product, including succinic anhydride, via catalytic oxidation with a manganese catalyst in acetic anhydride. Moreover, an unexpected product of maleic anhydride was obtained, which greatly differs from that of levulinate ester. The pathway for formation of maleic anhydride was studied by monitoring and confirming intermediates α-angelica lactone and its derivative 2-methyl-5-oxotetrahydro-2-furanyl acetate. Based on the obtained mechanistic information, the different behaviour between the oxidative cleavage of levulinic acid and levulinate ester was further discussed.
研究领域:
化学工程
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可再生资源化学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Chemistry & Engineering
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2023
·Vol. 8
·期 11
·2738-2745
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IF 3.9
Haoran Yuan,Chengyu Li,Rui Shan,Jun Zhang,Yong Chen
A series of antibiotic residue derived solid acids were developed for the selective transformation of bio-based furfuryl alcohol into ethyl levulinate. KOH modification and chlorosulfonic acid decoration of gentamicin residue derived carbon materials played a crucial role in ethyl levulinate production. Various characterization methods were employed for unveiling the structural information regarding porous characteristics and functional groups, such as FT-IR, N2 adsorption–desorption, SEM, etc. The yields of 2-(ethoxymethyl)furan and ethyl levulinate were particularly associated with the acid density of gentamicin residue derived solid acids. Gratifyingly, a maximum ethyl levulinate yield of 84.5% was achieved at 160 °C after 1.5 h. The recovery and reutilization of the catalyst in successive reactions demonstrated that gentamicin residue derived solid acids maintained good activity and stability even after four cycles. The present research thus highlights a novel direction for high-value utilization of antibiotic residues as well as the synthesis of platform chemicals over organic waste derived catalytic materials.
研究领域:
化学工程
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催化
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材料科学
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环境科学
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生物化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
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2022
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IF 8.035
Yishuang Wang,Jingjing Shi,Xiangsong Chen,Mingqiang Chen,Jun Wang,Jianming Yao
Cellulose conversion for ethyl levulinate (CCEL) production is a potential technology for obtaining liquid fuels. Combined the inherent characteristics of cellulose with “homogeneous reaction-heterogeneous separation” feature of heteropoly acids (HPAs), HPAs catalyzed CCEL under ethanol medium were investigated. Various characterizations confirmed HSiW had appropriate Brønsted and Lewis acid sites. Therefore, HSiW achieved the highest cellulose conversion (95.25 %) and ethyl levulinate (EL) yield (77.05 %), and EL selectivity reached to 75.15 % under optimized reaction conditions. Additionally, the reaction pathways of CCEL were proposed and the reactions of fructose dehydrated into hydroxymethylfurfural (HMF) and further alcoholysis into EL were improved by HPAs. The successfully established kinetic model of CCEL indicated the activation energies of cellulose conversion into HMF (26.90 kJ·mol −1 ) and HMF alcoholysis for EL (24.22 kJ·mol −1 ) were significantly lower than those of them transformed to humins (99.19 and 53.68 kJ·mol −1 ), suggesting HPAs catalysis could effectively inhibit humus generation.
研究领域:
生物化学
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可再生能源
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Mengzhu Li,Junnan Wei,Guihua Yan,Huai Liu,Xing Tang,Yong Sun,Xianhai Zeng,Tingzhou Lei,Lu Lin
Biomass-derived ethyl levulinate (EL) is currently deemed as a promising fuel bioadditive to improve (bio)diesel combustion performance without the sacrifice of its octane number . In this contribution, a range of Zr–Al bimetallic catalysts were prepared for the cascade conversion of furfural to EL by the integration of transfer hydrogenation and ethanolysis in ethanol. The ratio of Lewis to Brønsted acid sites (L/B) could be tuned by the ratio of Al 2 O 3 to ZrO 2 over SBA-15 support. Among these catalysts, Zr–Al/SBA-15(30:10) with appropriate L/B ratio of 2.25 exhibited an outstanding catalytic performance to give a furfural (FF) conversion up to 92.8% with a EL selectivity as high as 71.4% at 453 K in 3 h.
研究领域:
催化化学
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可再生资源利用
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生物质能
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Shijie Wang,Yihang Chen,Yu Jia,Chen Wang,Guizhuan Xu,Youzhou Jiao,Chao He,Chun Chang,Qianhui Guo
An effective catalytic strategy for the conversion of glucose to 5-ethoxymethylfurfural (EMF) catalyzed by ultrastable Y zeolite (USY) in a co-solvent system was developed. Effects of co-solvent and reaction conditions were first investigated. Tetrahydrofuran (THF) with low dipolarity/polarizability (π*) was screened as the appropriate co-solvent, and a higher EMF yield of 41.46% was obtained as the ratio of ethanol to THF was 7:3. The macroscopic reaction kinetic study indicated that THF can protect EMF from easy degradation to EL. Moreover, the reusability and the characterization of USY verified the feasibility of USY as an efficient solid acid catalyst. In this study, density functional theory (DFT) calculations for the catalytic mechanism and solvent effect at the molecular scale were performed for the first time. The extra-framework aluminum species (EFAL), in which Al 3+ played an essential role in the reaction as the preferred EFAL species, and THF can reduce the energy barrier of USY-catalyzed glucose isomerization . Meanwhile, the inhibitory effect of THF on EMF alcoholysis was explored via the frontier molecular orbital theory. The results showed that THF increased the LUMO energy of EMF compared with ethanol and γ-valerolactone, which decreased its susceptibility to nucleophilic attack and reduced the adverse alcoholysis of EMF and humins formation. This study provided an enlightening reference for the efficient synthesis of EMF from carbohydrates catalyzed by solid acid catalyst under solvent effect.
研究领域:
化学工程
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催化化学
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计算化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Rui Kang,Dayi Guo,Xinyi Luo,Hui Pan
Catalytic hydrogenation of ethyl levulinate (EL) to 1,4-pentanediol (1, 4-PDO) could provide a potential approach to obtain valuable chemicals from renewable biomass. In this study, a CuZr/CoOx catalyst was developed based on a structural topotactic transformation process of layered double hydroxides. The prepared CuZr/CoOx catalysts possess a double functionality of metal-acid sites and showed superior catalytic activity in the production of 1, 4-PDO from cascade conversion of EL. A complete EL conversion (100 %) and 93.1 % 1, 4-PDO yield were obtained under optimized conditions over catalyst CuZr/CoOx-400. The co-existence of Cu 0 and Cu + on the surface of catalyst CuZr/CoOx was confirmed by XRD and XAES characterizations. In addition, the XPS results suggested a strong interaction between Co and Cu, which would effectively stabilize the Cu + species in the catalyst. The Cu 0 was believed to activate hydrogen, while the Cu + could promote the adsorption of carbonyl group of the substrate thus facilitating the hydrogenolysis. The introducing of Zr in the catalyst greatly improved the dispersion of Cu species and increased the abundance of the acid sites as revealed by the TEM and NH 3 -TPD analysis. Catalyst CuZr/CoOx-400 also exhibited highly catalytic activity after five reaction cycles. Together with the low cost of the non-precious metals, the CuZr/CoOx catalysts demonstrate a potential for the scaled-up application in the biomass refinery process.
研究领域:
催化化学
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生物质能
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可再生资源
✓ 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）