生物质在流化床中的空气-水蒸气气化研究

以流化床为反应器，对生物质的空气-水蒸气气化特性进行了研究。考察了一些主要参变量，如温度 (700 ℃～900 ℃)、水蒸气/生物质比(0～4.04)、空气当量比(0.19～0.27)以及生物质粒度(0.2 mm～0.9 mm)等对气化结果的影响。在实验研究的条件范围内，生物质产气率在1.43 m3/kg～2.57 m3/kg范围内变化，产气的低热值在6 741 kJ/m3～9 143 kJ/m3范围内变化。实验结果表明：较高的气化温度有利于氢的产生；但气化温度过高会使气体热值下降；与常规的空气气化相比，水蒸气的加入使生物质气化产气率显著提高，但水蒸气加入量过多使气化温度下降，产气率和产气热值降低；生物质颗粒粒度的大小对产气组分的分布和产气率均有影响，较小颗粒的生物质会产生较多的CH4、CO和较少的CO2。

AN EXPERIMENTAL RESEARCH ON BIOMASS AIR-STEAM GASIFICATION IN A FLUIDIZED BED

The characteristics of biomass air-steam gasification in a fluidized bed were analyzed in this paper through a series of experiments. The effects of reactor temperature (700℃～900℃), steam to biomass ratio (0～4.04), equivalence ratio (0.19～0.27) and biomass particle size (0.2mm～0.9mm) on gas composition, gas yield, steam decomposition, lower heat value (LHV) of fuel gas were investigated. Under the experimental conditions examined, the fuel gas yield ranges between 1.43 Nm3/kg and 2.57 Nm3/kg biomass and the LHV of fuel gas ranges between 6741kJ/m3 and 9143 kJ/m3. The results show that higher temperature contributes to more hydrogen production, but lower LHV. Compared with biomass air gasification, the introduction of steam improves gas quality. But excessive steam will lower gasification temperature and degrade fuel gas quality. The biomass particle size also has influence on gas composition and gas yield. The smaller particle yields more CH4 and CO, but less CO2.