基于TG-FTIR的生物质催化热解试验研究

运用热重－傅里叶红外光谱联用技术(TG-FTIR)，以麦秸为研究对象，探讨催化与非催化条件下生物质的热解挥发分析出特性，分析研究热解温度、催化剂种类对生物质热解主要析出产物的影响。通过热重TG和DTG曲线，获得了相关热解特性参数及动力学参数。结果表明，添加NiO和CaO存在两个失重峰，并促进麦秸热解反应进行，降低表观活化能，其中NiO对提高热解析出产率作用更显著。通过红外光谱对热解产物实时测量的分析表明，CO与CO2的析出与失重峰基本一致，而CH4的析出滞后于前两者。添加NiO和CaO有利于减少热解产物中的CO2的浓度，促进挥发分产物CO、CH4的生成。其中CaO更有利于生物质在温度800℃以下的热解性能改善，而NiO在800℃以上具有更好的催化作用。

TG-FTIR study on catalytic pyrolysis of biomass

Pyrolysis characteristics and kinetics of wheat straw were investigated using a thermogravimetric analyzer coupled with Fourier transform infrared analyzer (TG-FTIR) under catalytic and non catalytic conditions. The effects of pyrolysis temperature and catalyst on composition of volatile products were discussed. The pyrolysis parameters were obtained based on TG and DTG curves. The composition of pyrolysis products was on line analyzed by FT-IR. The results show that two thermogravimetric peaks appear on DTG curves using nickel oxide and calcium oxide as catalyst, but only one peak appears without the catalysts. Thus the biomass pyrolysis characteristics can be improved under catalytic condition. Nickel oxide has more remarkable effect on increasing biomass pyrolysis yields, picking up volatile releasing rate, and decreasing apparent activation energy. CO and CO2 release peak is consistent with the maximal weight loss rate in DTG. CH4 is formed later than CO and CO2. In addition, using nickel oxide and calcium oxide as catalyst CO and CH4 yields increase, whereas CO2 yield decreases. While temperature is below 800℃, calcium oxide is more helpful to improve fuel gas composition during pyrolysis. When the temperature is above 800℃, nickel oxide has better catalytic effect.