Effect of acid washing and torrefaction on pyrolysis products of biomass

doi:10.16085/j.issn.1000-6613.2017.02.015

Abstract

Abstract: Rice husk was selected as the raw material in this study. After combined acid washing and torrefaction pretreatment,the products from pyrolsis of raw and pretreated samples were analyzed. This study investigated the effect of acid washing and torrefaction pretreatment on pyrolysis products of biomass. It was found that alkali and alkaline earth metals were significantly removed by the combining pretreatment with acid washing and torrefaction. With the increase of C and the decrease of O and H,high heat value was increased,and the fuel characteristics were enhanced. It was found that higher bio-oil yield and lower char yield was obtained by light bio-oil washing pretreatment,and with the increase of the temperature of torrefaction,the bio-oil yield decreased,but the char yield increased. The results of gas products indicated that the relative content of combustible components was increased. For bio-oil,pretreatment resulted in a reduction of water content,but along with significant increase of pH and HHVs. The production of sugars was increased in bio-oil,while acids,ketones and furans were reduced. Pretreatment also developed the pore structure of char,specific surface area was increased,and the content of silica in rice husk ash was increased up to 98.91%. A new system on the comprehensive utilization of rice husk was proposed based on the current results.

Key words: acid washing, torrefaction, pyrolysis

摘要： 选用稻壳为原料，进行酸洗-烘焙联合预处理后，于550℃下热解，详细分析了固、液、气热解三相产物，考察酸洗-烘焙联合预处理对稻壳热解产物特性的影响。结果表明联合预处理移除了生物质中大部分碱金属和碱土金属，并且C元素含量增加，H和O元素含量逐渐减小，高位热值增加，因此样品的燃料特性得到了提高；酸洗后，热解生物油收益率显著提高，并随着烘焙温度的升高减小，生物焦则相反；热解产物中，不可凝气中可燃成分含量增加；生物油含水率减少，但是，pH和高位热值明显增加，化学成分中糖类产量增加，酸类、酮类和呋喃类产量减少，生物焦孔隙结构得到发展，比表面积增加，稻壳灰中二氧化硅的相对含量增加，达到98.91%。根据上述实验结果，提出了一种新的稻壳资源综合利用系统。

关键词: 酸洗, 烘焙, 热解

CLC Number:

CHEN Tao, ZHANG Shuping, LI Wan, XIONG Yuanquan. Effect of acid washing and torrefaction on pyrolysis products of biomass[J]. Chemical Industry and Engineering Progree, 2017, 36(02): 506-512.

陈涛, 张书平, 李弯, 熊源泉. 酸洗-烘焙预处理对生物质热解产物的影响[J]. 化工进展, 2017, 36(02): 506-512.

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