INDUSTRIAL CROPS AND PRODUCTS
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2022
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IF 6.449
Guangchuan Tang,Xin Huang,Anbang Xu,Zhongqing Yang,Changlei Qin,Jingyu Ran
Pyrolysis of cellulose produces substantial anhydrosugars, particularly levoglucosan (LGA), as the main product. In this study, liquid-phase continuous conversion of LGA was carried out over SO 3 H functionalized resin for the production of levogluosenone (LGO), which is a bio-renewable platform for fine and commodity chemicals. Factors including solvent, reaction temperature, catalyst dosage, initial LGA concentration and total flow rate were investigated on the influence of LGO yield, which was obtained with the highest yield of 38.4 % at 94.8 % LGA conversion at the optimized conditions. In addition, a stable catalytic performance without losing LGO yield was observed for 10 h long test. The use of glucose as substrate led to a decrease of LGO yield to 33.5 %, nevertheless, the use of bio-oil, derived from cellulose pyrolysis, as the substrate promoted LGO yield to 55.4 % due to the presence of other anhydrosugars. Density functional density calculations revealed that the free energy barrier was significantly decreased to 168 kJ/mol with the SO 3 H functionalized resin compared to that of 258 kJ/mol without catalyst.
研究领域:
生物化学
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可再生资源与环境工程
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产品关联
DOI
高影响因子
ENERGY & FUELS
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2017
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IF 3.091
Bin Hu,Qiang Lu,Xiao-yan Jiang,Xiao-chen Dong,Min-shu Cui,Chang-qing Dong,Yong-ping Yang
Fast pyrolysis of glucose/cellulose will produce abundant 1,6-anhydro-β-d-glucopyranose (known as levoglucosan, LG) as the predominant anhydrosugar product, together with certain amounts of other anhydrosugars, mainly including 1,6-anhydro-β-d-glucofuranose (AGF), 1,4:3,6-dianhydro-α-d-glucopyranose (DGP), 1,5-anhydro-4-deoxy-d-glycero-hex-1-en-3-ulose (APP), 1-hydroxy-3,6-dioxabicyclo[3.2.1]octan-2-one (LAC). The formation mechanisms of the latter four anhydrosugar products are not well-known at present. Substantiated by analytical pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) experiments, quantum chemistry calculations are employed to give a deep insight into their formation mechanisms in this study. The anomeric effect of glucopyranose has a distinct effect to their formation. DGP is mainly derived from α-d-glucopyranose which plays a vital role in the formation of 1,4-acetal ring. On the contrary, APP and LAC can merely derive from β-d-glucopyranose due to the dehydration at 1-OH + 2-H site. APP is important but not necessary to form LAC, and their formation pathways also compete with each other. Moreover, AGF is not influenced by the anomeric effect of the two anomers, because its formation relies on the acyclic d-glucose.
研究领域:
生物化学
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分析化学
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DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
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2023
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IF 5.9
Anfu Hu,Qian Xia,Jun Wang,Tan Li,Kaige Wang,Jian Wu,Guojun Zhou,Jian Jiang
The effect of alkali and alkali earth metals on pyrolysis behavior of tobacco was revealed in this paper. Four alkali and alkali earth metal ions (Na + , K + , Ca 2+ , and Mg 2+ ) were used to impregnate acid-washed tobacco. The addition of alkali and alkali earth metal ions in acid-washed tobacco increases the relative content of ketones, acids, nitrogen containing compounds, and esters, while inhibit the formation of anhydro sugars and aldehydes. The generation of solid residues is enhanced by the presence of alkali and alkali earth metal ions and the increase of K + concentration. The addition of 0.5 mmol K + /g can increase the yield of solid residues from 13.7 wt% to 20.2 wt%. The increase of K + concentration promotes the conversion of anhydro sugars to ketones. The effect of hot water-wash, acid-wash, and acid-infuse, which can control the concentration of alkali and alkali earth metal ions in the tobacco, on the product distribution of tobacco pyrolysis were also discussed. Acid-wash method and hot water-wash method promote the production of carbohydrate derivatives and inhibit the generation of nitrogen-containing products. After nitric acid-wash and hot water-wash pretreatment , the relative content of nitrogen-containing products decreased from 52.1% to 6.2% and 4.3%, respectively. Compared with inorganic acid-wash pretreatment method, organic acid-wash pretreatment method has weaker inhibition on nitrogen-containing products. Organic acid-wash pretreatment method promoted the formation of aromatics and aldehydes. Prewash methods facilitate the thermal decomposition of tobacco. The results from this study suggests that feedstock pretreatment could be used as a strategy of controlling aroma compounds formation from tobacco.
研究领域:
化学工程
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环境科学
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材料科学
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农业工程
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DOI
高影响因子
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