JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2019
·Vol. 95
·期 3
·798-805
·
IF 2.659
Dan Luo,Shengnan Liu,Wang Yin,Shuqian Xia
BACKGROUND Fast pyrolysis of lignocellulosics has provided an abundant sugar source for production of value-added chemicals, and levoglucosan is the most representative sugar in pyrolysis liquid (bio oil). This paper explored the potential for producing methyl lactate from levoglucosan by employing the mixed catalysts of zeolite tin beta (Sn-Beta) and zeolite hydrogen beta (H-Beta). RESULTS Under the optimal conditions (at 200 °C and mixed catalysts with H-Beta:Sn-Beta ratio of 1:5), the yield of methyl lactate obtained from levoglucosan conversion was as high as 35%. And the yield was comparable to that of methyl lactate obtained from glucose conversion under the similar conditions (at 200 °C and pure Sn-Beta). In order to investigate the reason, a contrasting experiment with glucose as substrate also was carried out with the mixed catalysts. The results indicated that during the levoglucosan conversion process, ‘the methanolysis of levoglucosan’ was likely to compete with ‘the dehydration of glucose’ for the Brønsted acid sites of H-Beta. In addition, the catalytic functions of H-Beta and Sn-Beta, and the reaction pathway were deeply investigated through tracking and comparing the conversion of levoglucosan over mixed H-Beta/Sn-Beta and over pure Sn-Beta catalysts, respectively. CONCLUSION The appropriately lower ratio of H-Beta:Sn-Beta and relatively higher temperature were favorable for the reaction. H-Beta containing Brønsted acid could remarkably accelerate the conversion of levoglucosan and methyl-glucosides to glucose. Sn-Beta containing Lewis acid mainly promoted the retro-aldol condensation of glucose and formation of methyl lactate. © 2019 Society of Chemical Industry
研究领域:
化学工程
·
生物质能
·
催化化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Miao Wang,Shuai Zhang,Xiangjun Liu,Yayun Ma,Junqi Wang
A comprehensive study of alkali and alkaline earth metal (AAEM) salts including two different anions (Cl - and CH 3 COO - ) in the catalytic pyrolysis of cellulose to produce levoglucosan (LG), bio-oil, and biochar were investigated. At the same time, the catalytic pyrolysis mechanism was also speculated. The thermogravimetric analyzer (TGA) and lab-scale fixed-bed reactor system were used to determine the thermal degradation process and the pyrolysis products of LG, bio-oil, and biochar. The optimized pyrolysis parameters were obtained by using Box-Behnken design-response surface method. According to the results, AAEM salts significantly boosted the yield of biochar, as well as greatly cut down the output of LG and bio-oil. The rank of effect on LG yield was as follows: CaCl 2 , MgCl 2 > CH 3 COOK, CH 3 COONa > (CH 3 COO) 2 Mg, (CH 3 COO) 2 Ca > KCl, NaCl. Moreover, the addition of AAEM salts considerably dropped the activation energy E of cellulose pyrolysis as well as prompted microcrystalline cellulose pyrolysis under lower temperatures. This study was pivotal in deducing the pathway of cellulose pyrolysis, thereby offering critical insights to hasten the progress of biomass utilization.
研究领域:
能源与燃料
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Bioresources and Bioprocessing
·
2024
·Vol. 11
·期 1
·1-10
·
IF 4.3
Wang Cong,Chang Dongdong,Zhang Qi,Yu Zhisheng
Lignocellulose pretreated using pyrolysis can yield clean energy (such as bioethanol) via microbial fermentation, which can significantly contribute to waste recycling, environmental protection, and energy security. However, the acids, aldehydes, and phenols present in bio-oil with inhibitory effects on microorganisms compromise the downstream utilization and conversion of lignocellulosic pyrolysates. In this study, we constructed a microbial electrolysis cell system for bio-oil detoxification and efficient ethanol production using evolved Escherichia coli to overcome the bioethanol production and utilization challenges highlighted in previous studies. In electrically treated bio-oil media, the E. coli-H strain exhibited significantly higher levoglucosan consumption and ethanol production capacities compared with the control. In undetoxified bio-oil media containing 1.0% (w/v) levoglucosan, E. coli-H produced 0.54 g ethanol/g levoglucosan, reaching 94% of the theoretical yield. Our findings will contribute to developing a practical method for bioethanol production from lignocellulosic substrates, and provide a scientific basis and technical demonstration for its industrialized application.
研究领域:
生物技术
·
环境科学
·
生物能源
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Ji Liu,Hao Fu,Bin Hu,Wan-yu Fu,Kai Li,Li Zhao,Bing Zhang,Qiang Lu
Catalytic fast pyrolysis of biomass/cellulose is a promising way for the production of levoglucosenone (LGO) and other value-added anhydrosugars. Herein, ammonium dihydrogen phosphate (NH 4 H 2 PO 4 ) modified mesoporous niobium pentoxide (P-Nb 2 O 5 ) was first applied to selectively produce LGO. The catalyst had a stable amorphous mesoporous structure with abundant activity species (Nb-O-Nb, Nb-O-P, P-OH, and PO 4 3- ), which affected the dehydration and depolymerization reactions of cellulose to alter the competing relationship between levoglucosan (LG) and LGO. Micro-scale pyrolysis experiments demonstrated that the yield of LGO reached 19.6 wt% under the optimized condition (P loading of 50 wt%, pyrolysis temperature of 400 °C, and catalyst-to-cellulose mass ratio of 7). In lab-scale experiments, the highest yield of LGO attained 16.5 wt%, and the catalytic activity could maintain over 80% after five recycles. Overall, the P-Nb 2 O 5 has been proven to be a promising catalyst to produce LGO from cellulose.
研究领域:
催化
·
化学工程
·
可再生能源
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Bin Hu,An-shuai Cheng,Yang Li,Yao-bing Huang,Ji Liu,Bing Zhang,Kai Li,Li Zhao,Ti-peng Wang,Qiang Lu
Selective preparation of value-added products via fast pyrolysis is a sustainable way for biomass utilization. We developed a novel strategy, oxalic acid-assisted fast pyrolysis (OAFP) of cellulose, which achieved the selective production of a promising anhydrosugar, 1,4:3,6-dianhydro-α- d -glucopyranose (DGP), for the first time. Effects of temperature and the mass ratio of cellulose-to-oxalic acid (Cell/OA) in their solid mixture were explored. The yield of DGP could be up to 14.0 wt% (based on cellulose) at 400 °C and the Cell/OA mass ratio of 1:9 with a lab-scale setup, about 200 times higher than that from fast pyrolysis of pure cellulose. According to the experiments and density functional theory (DFT) calculations, it was OA rather than its pyrolysis vapors (mainly formic acid) that played the predominant role in the selective generation of DGP, where OA acted as a reactant and a catalyst-like material at the same time. The formation of DGP competed with that of levoglucosan (LG), the most typical product in the fast pyrolysis of pure cellulose, and a small amount of DGP came from the secondary conversion of LG. The esterification of free hydroxyl at C3 or C6 position with OA determined the selective generation of DGP by promoting the formation of the C1 = C2 bond and the 3,6-acetal ring, and the generation of the 1,6-acetal ring was inhibited correspondingly which led to the decrease of LG. In addition, the OAFP process also showed the potential for poly-generation of value-added chemicals, syngas, and char.
研究领域:
化学工程
·
生物质转化
·
催化
·
可持续化学
·
材料科学
✓ 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）