摘要
基于生物质气化技术,采用下吸式气化炉为反应器,以高温水蒸气作为气化剂,选取温度和S/B(水蒸气流量与生物质气化量比)作为影响因素,炉体温度的变化范围700~950℃,S/B取值范围0.3~1.0,对产品气的组分变化规律进行分析,探讨了炉内的气化反应特性。试验结果表明,下吸式气化炉碳层内的水蒸气气化反应及焦油裂解反应对制取富氢燃气有重要作用,H2和CO的产率随温度的升高而增加,在温度增加到一定值后,H2体积分数达到峰值,继续升高温度导致H2的体积分数有所下降。S/B的增加有利于产品气中的H2含量的提升,但吸热反应造成炉内床体的反应温度下降,抑制H2体积分数的增加。在本试验条件下,H2的体积分数最大达到47.67%,对应的工况S/B为1.0.温度为900℃。
Experimental results are presented on the gasification of pine sawdust pellets using high temperature steam as the gasification agent. Downdraft gasifier was adopted as reactor, the reactor temperature was varied from 700℃ to 950℃ , and steam to biomass ratio (S/B) was changed from 0.3 to 1.0. Based on biomass gasification technology, the gasification characteristics of pine sawdust pellets were deeply discussed. In addition, numerical computation using Gibbs free energy minimization was applied and compared with the experimental results. The results show that hydrogen-rich gas could be effectively produced by high temperature steam in downdraft gasifier, and the carbon layer played an important role in preparation of hydrogen-rich gas, in which steam reforming reaction and tar cracking were taken place. H2 and CO yields would rise at higher temperature, and H2 volume fraction would reach the peak when reactor temperature raised some value, H2 fraction would decline if the temperature was continued to raise. The increase of S/B could develop H2 content of product gas, temperature of material bed would be dropped by some endothermic reactions, and the increase of H2 volume fraction was restrained. In the test, the peak value of H2 volume fraction was 47.67% with S/B of 1.0 and temperature of 900℃. These results also provide the operating law for downdraft gasifier with high temperature steam.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2015年第11期208-213,共6页
Transactions of the Chinese Society for Agricultural Machinery
基金
内蒙古自然科学基金资助项目(2015MS0106)
内蒙古科技创新引导奖励计划资助项目(01850401)
关键词
松木屑成型颗粒
高温蒸汽气化
富氢气体
下吸式气化炉
Pine sawdust pellets High temperature steam gasification Hydrogen-rich gas Downdraft fixed bed gasifier