基于铁矿石载氧体25kW_(th)串行流化床生物质化学链气化实验研究

Experimental study on chemical looping gasfication of biomass with hematite base on 25kW_(th) fluidized beds

设计并建立了25kW_(th)串行流化床生物质气化反应器,基于此反应器,以赤铁矿石作为载氧体,开展生物质化学链气化实验研究,考察气化反应器温度、S/B、载氧体添加比例对生物质气化特性的影响。当赤铁矿占床料比例高于40%时,该气化装置的气化反应器温度保持平稳,铁矿石载氧体的再生及传热性能优良。燃料反应器出口烟气的成分为H_2、CO_2、CO、CH_4和少量的C_2H_4。随着气化反应器温度升高,气化反应器出口烟气中CO、CH_4和C_2H_4体积分数逐渐降低,相应的CO_2体积分数逐渐升高。随着S/B由0.6升高到1.4,气化反应器出口烟气中H_2和CO_2体积分数逐渐升高,CO、CH_4和C_2H_4体积分数逐渐降低。另外,载氧体添加比例增加,生物质气化反应器出口烟气中CO、H_2、CH_4和C_2H_4体积分数呈减小的趋势,而CO_2体积分数显著增加。

A 25 kWthinterconnected fluidized beds prototype was designed and constructed firstly.Based on this prototype,biomass gasification using iron ore as an oxygen carrier was investigated.Effects of temperature,ratio of steam to biomass（S/B）,additive proportion of oxygen carrier on the biomass gasification were experimentally performed.The experimental results showed that the main compositions in the exit gas of the gasification reactor were H2,CO2,CO and a little CH4 and C2H4.With the increase of gasification temperature,the exit concentrations of CO,CH4 and C2H4gradually decreased,and CO2 concentration increased.With the increase of S/Bfrom 0.6to 1.4,more CH4 and C2H4 were converted to CO and H2,leading to a decrease of CH4 and C2H4 concentration in the syngas.The CO concentration in the gasification reactor decreased with the increase of S/B,but the CO2 and H2concentrations demonstratedopposite trends.when the addition of the amount of oxygen carrier became larger.It led to a lower CO and H2 formation and a higher CO2 production in the syngas.