两段式固定床富氧－水蒸气气化实验研究

以玉米芯颗粒为原料在两段式固定床气化装置上进行了气化实验，考察了当量比ER、富氧浓度OC和水蒸气配比S/B对气化温度、气化气组分、低位热值、气体产率、气化效率和碳转化率等参数的影响，并比较了两段式固定床与传统下吸式固定床的气化特性。实验结果表明,当量比为0.27时H₂的体积分数、CO的体积分数和气化效率达到最大值；增加富氧浓度能优化气化效果，但富氧浓度大于90%后，燃气质量和气化效率均提高不大；增加S/B能提高H₂的体积分数，但同时会降低CO的体积分数、气体热值、气化效率；当S/B为0.6时，氢气的体积分数达最高值33.3%，H₂/CO比为1.32；相比于传统固定床，两段式固定床气化可明显提高气化温度、氢气的体积分数、碳转化率和气化效率，降低焦油含量。

Experimental study on biomass steam-oxygen enriched air gasification in a two-stage fixed bed gasifier

The experiments on the gasification of corncob chips with steam-oxygen enriched air was carried out in an atmospheric two-stage fixed bed gasifier. The effects of equivalence ratio (ER), oxygen concentration (OC) and steam to biomass ratio (S/B) on the gasification temperature, gas compositions, lower heating value, gas yield, carbon conversion and cold gas efficiency were investigated, and the gasification characteristics between conventional downdraft fixed bed and two-stage fixed bed was compared. The results show that under the operating conditions of ER=0.27, H₂ content, CO content and cold gas efficiency reach their maximums; Enhancing oxygen concentration can optimize the gasification performance, but it is less to further improve the fuel gas quality as the OC exceeds 90%. By increasing S/B, the H₂ content, CO₂ content and gas yield are increased, but the CO content, cold gas efficiency and carbon conversion are decreased. H₂ content reachs maximum of 33.3% at the S/B of 0.6, while H₂/CO ratio reachs 1.32. Compared with conventional downdraft fixed bed, the two-stage fixed bed has a higher gasification temperature, H₂ content, carbon conversion, cold gas efficiency and a lower tar content.