Effects of lignin species and catalyst addition on pyrolysis products

被引：0
|
作者：
Ma Z. [1 ]
Wang J. [1 ]
Huang M. [1 ]
Cai W. [1 ]
Xu J. [1 ]
Yang Y. [2 ]
机构：
[1] School of Engineering, Zhejiang Provincial Collaborative Innovation Center for Bamboo Resources and High-Efficiency Utilization, Zhejiang A&F University, Hangzhou
[2] School of Humanities and Law, Zhejiang A&F University, Hangzhou
来源：
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | 2020年 / 36卷 / 01期
关键词：
BTX; Catalytic fast pyrolysis; Lignin; Zeolite;
D O I：
10.11975/j.issn.1002-6819.2020.01.033
中图分类号：
学科分类号：
摘要：
Benzene, toluene, and xylene (BTX), are value-added aromatic platform chemicals that have been widely used in the synthetic resin, rubber, dye, agrochemical, and pharmaceutical industries. Owing to the natural aromatic structure, lignin has a great potential to serve as starting material for the production of BTX by catalytic fast pyrolysis (CFP) process. In this work, four types of lignin isolated from palm kernel shell with different severities, namely milled wood lignin (MWL), alkali lignin (AL), Klason lignin (KL), and organosolv ethanol lignin (OEL) were used in lignin CFP process. First, the characteristics of zeolite catalyst (HZSM-5 with Si/Al ratio of 25) were analyzed by X-ray diffraction (XRD), automatic specific surface area and pore size distribution analyzer (BET) and automatic chemical adsorption instrument (NH3-TPD), etc. Then, the effects of lignin types and lignin/catalyst ratios (1:1,1:2,1:3, and 1:5) on the product distribution during lignin catalytic fast pyrolysis process were investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TGA-FTIR) and pyrolyzer coupled with gas chromatography/mass spectrometer (Py-GC/MS). Results were showed as followed: 1) Based on the structural characterization analysis of the catalyst, the crystal form of HZSM-5 was dense hexagonal crystal structure. The dominant pore size distribution in HZSM-5 was microporous, and the content of weak acid in HZSM-5 was higher than strong acid. 2) Based on the ultimate analysis of four types of lignin, MWL has the highest content of C and H elements (62.96 % and 7.24 % respectively)and highest effective hydrogen/carbon ratio of 0.67, while AL had lowest effective hydrogen/carbon ratio of 0.29 and highest O content of 44.25%, indicating that AL contains more oxygen-containing functional groups and β-O-4 linkages. 3) Based on the TGA-FTIR analysis, due to the larger weight-average molecular weight (Mw) and polydispersity coefficient (PDI), MWL had widest temperature range of weight loss and maximum number of weight loss peaks. But the AL residual carbon rate is the lowest, indicating that AL has the worst thermal stability and the volatiles in the AL are more converted into pyrolysis gases and liquid products. Among the four types of lignin, the release amount of small molecular weight components (H2O, CH4, CO2 and CO) showed an increase tendency with the increase of lignin/catalyst ratio. 4) Based on the Py-GC/MS analysis, the bio-oil of lignin CFP was mainly composed of S-typed phenols, G-typed phenols, P-typed phenols, C-typed phenols, and aromatics. With the increase of lignin/catalyst ratio, the content of total phenols was gradually decreased, and it was converted into aromatics by a series of deoxygenation reactions, such as the decarboxylation reaction, the decarbonylation reaction, and the breakage of ether bond. Among the four types of lignin, the highest value of effective hydrogen-carbon ratio was obtained in MWL (0.69), which made MWL a more favorable starting material for the production of BTX. MWL had the highest content of aromatics during CFP process because of its highest effective hydrogen/carbon ratio. The contents of benzene, xylene, and toluene of MWL CFP process reached their maximum values of 4.51×107, 1.26×108, and 8.58×107, when the lignin/catalyst ratios were 1:5,1:3, and 1:3, respectively. The results of this work could provide basic data for the production of high value-added chemicals (BTX) from lignin by CFP. © 2020, Editorial Department of the Transactions of the Chinese Society of Agricultural Engineering. All right reserved.
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页码：274 / 282
页数：8
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共 37 条
  • [1] Fan M.H., Deng S.M., Wang T.J., Et al., Production of BTX through catalytic depolymerization of lignin, Chinese Journal of Chemical Physics, 27, 2, pp. 221-226, (2014)
  • [2] Dai H., Outlook of aromatics production technology, Petroleum Processing and Petrochemicals, 44, 1, pp. 1-10, (2013)
  • [3] Ma Z., Wang J., Li C., Et al., New sight on the lignin torrefaction pretreatment: Relevance between the evolution of chemical structure and the properties of torrefied gaseous, liquid, and solid products, Bioresource Technology, 288, (2019)
  • [4] Ma Z., Wang J., Zhou H., Et al., Relationship of thermal degradation behavior and chemical structure of lignin isolated from palm kernel shell under different process severities, Fuel Processing Technology, 181, pp. 142-156, (2018)
  • [5] Chen D., Gao A., Cen K., Et al., Investigation of biomass torrefaction based on three major components: Hemicellulose, cellulose, and lignin, Energy Conversion and Management, 169, pp. 228-237, (2018)
  • [6] Jia Q., Zhu L., Fan M., Et al., Catalytic pyrolysis of lignin for directional production of p-Xylene over metal oxides-modified HZSM-5 catalysts, Chin. J. Org. Chem, 38, 8, pp. 2101-2108, (2018)
  • [7] Wang S., Lin H., Ru B., Et al., Comparison of the pyrolysis behavior of pyrolytic lignin and milled wood lignin by using TG-FTIR analysis, Journal of Analytical and Applied Pyrolysis, 108, pp. 78-85, (2014)
  • [8] Ma Z., Chen D., Gu J., Et al., Determination of pyrolysis characteristics and kinetics of palm kernel shell using TGA-FTIR and model-free integral methods, Energy Conversion and Management, 89, pp. 251-259, (2015)
  • [9] Liu Q., Wang S., Zheng Y., Et al., Mechanism study of wood lignin pyrolysis by using TG-FTIR analysis, Journal of Analytical and Applied Pyrolysis, 82, 1, pp. 170-177, (2008)
  • [10] Ma Z., Wang J., Yang Y., Et al., Comparison of the thermal degradation behaviors and kinetics of palm oil waste under nitrogen and air atmosphere in TGA-FTIR with a complementary use of model-free and model-fitting approaches, Journal of Analytical and Applied Pyrolysis, 134, pp. 12-24, (2018)
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