木屑水蒸气气化热重分析及合成气释放特性

Thermal gravimetric analysis and syngas releasing characteristics of sawdust steam gasification

试验研究了木屑在水蒸气气氛下的热失重行为及气化过程中合成气释放特性。首先采用TG-DTA对木屑样品进行了水蒸气气氛下的热重行为分析,结果表明,木屑气化过程可以分为挥发分释放和半焦气化两个阶段,分别可由二级反应动力学和三维扩散Ginstling-Broushtein方程描述,对应的表观活化能分别为87.014kJ/mol和103.35 kJ/mol。此外,在自制的固定床气化反应装置上,研究了生物质气化过程中挥发分释放和半焦气化阶段合成气释放特性。另外,半焦水蒸气气化阶段对气体中合成气含量和H2/CO起到决定性作用,通过合理调控半焦气化阶段反应条件,可以得到合适化学当量比的生物质合成气。

The thermal behavior of pine sawdust in steam atmosphere and syngas releasing proper- ties during gasification process were studied. First, the thermal gravimetric analysis of sawdust was taken by TG-DTA, and sawdust pyrolysis behavior in steam atmosphere showed that gasification process could be divided into two stages,devolatilization and char gasification,which could be de- scribed by the Second-order reaction and Ginstling-Brounshtein equation respectively. The corre- sponding apparent activation energies were 87.014 kJ/mol and 103.35 kJ/mol. In addition,the syngas releasing behavior of devolatilization and char gasification stage of pine sawdust gasification was ex- amined in a self-made fixed-bed reactor.The results showed that char gasification stage plays a key role in the syngas content and HJCO value. Through reasonable regulation and control of the reac- tion condition of char gasification stage, the preferable stoichiometric ratio could be adjusted for desired synthesis products.