摘要
为了获得生物质在闪速加热条件下的热解挥发特性,引入一套层流炉系统进行实验研究。可变工况参数包括反应加热温度从800K至950K变化,热解停留时间从0.108～0.224s变化。实验材料是粉碎的玉米秸秆,粒径0.117～0.173mm,不作为变量考虑。利用等离子体加热技术,可以保证层流炉内部温度稳定保持在恒定设置数值。工作气体为氩气,流量1.5～2.5m3/h。热解残炭由一个水冷收集器(冷激器)收集,并且利用旋风分离器与气流分离。利用灰分示踪法确定玉米秸秆粉末热解的挥发程度。引入Arrhenius形式的一级挥发反应模型分析实验数据,得到了相应的热化学动力学参数。结果表明,闪速加热热解与慢速热解存在明显不同,与加热速率无关。闪速加热挥发特性对于研究生物质液化机理有重要意义。
The pyrolysis of pulverized corn stalk has been studied in a laminar entrained flow furnace with the aim of determining the devolatilization characteristics of biomass particles at flash heating rate. Variables investigated were reaction temperature between 800 K and 950 K and residence time between 0 .108 s and 0.224 s. Pulverized corn stalk particle size, ranging between 0.117 and 0.173 mm, was not controlled as a variable in this study. Plasma jet flow was used as the heating source to achieve a stable and controllable high temperature gas flow for the flash pyrolysis of biomass in the furnace. Argon was used as the working gas with flow rate ranging from (1.5) to 2.5 m^3/h. The solid product of pyrolysis (char) collected by a water-cooled collecting tube (quench unit) and a cyclone collector was used for determining the volatilized fraction of the biomass being pyrolyzed via the ash content in the solid as a tracer. Based on the experimental results, an Arrhenius form first order reaction kinetic model of biomass pyrolysis in the furnace was introduced and relevant kinetic parameters of corn stalk pyrolysis were determined. The results show that the devolatilization characteristics of fast pyrolysis differs from that of slow pyrolysis. The studies on biomass devolatilization characteristics at flash heating rates are very important in the investigations of biomass pyrolysis liquefaction mechanism.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2004年第6期246-250,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家863计划资助项目(2001AA514030
2003AA514030)
国家自然科学基金资助(50376031)
教育部高等学校骨干教师资助项目
关键词
生物质能
热裂解
闪速加热
层流炉
挥发特性
biomass energy
pyrolysis
flash heating
laminar flow reactor
devolatilization characteristics
