基于铁矿石载氧体的生物质化学链气化机理研究

Mechanism study of biomass chemical looping gasification based on iron ore as oxygen carrier

在单批次进料小型流化床上,以稻壳为生物质燃料,研究了床料、气化温度、水蒸气体积分数以及载氧体载氧量与生物质含碳量的摩尔比(O/C)对生物质化学链气化反应特性的影响,并考察了铁矿石的长期交替氧化还原过程中的反应特性,分析了在小型流化床,水蒸气气氛气化条件下,铁矿石载氧体在反应过程中主要的反应以及反应后的铁矿石的床料变化。研究表明:在载氧体条件下,生物质的碳转化率显著增大,随着反应温度的升高,合成气中的H_2和CO的体积分数也相应升高。在温度不变情况下,随着水蒸气比例的升高,CO_2和H_2的体积分数显著上升。伴随着O/C摩尔比的升高,CO和H_2均显著下降。因此,在不同的反应条件下,铁矿石在生物质化学链气化过程中对反应速度、合成气比例等均有明显的作用,对研究生物质的综合利用具有一定的意义。

The effects of oxygen carrier, gasification temperature, steam concentration, molar ratio of lattice oxygen to carbon （O/C） and multiple cycleson gasification characterization were investigated in a single fluidized bed. The iron ore demonstrated stable reaction character during multiple cycles. Under the steam condition, the main reactions of iron ore occur in the process of the gasification and the change of the bed material was analyzed. The results show that, under the condition of oxygen carrier, the biomass carbon conversion rate increases significantly with an increase in reaction temperature; H2 and CO concentration in the syngas also increases accordingly. Under the condition of same temperature, with an increase in steam proportion, the concentration of CO2 and H2 also increases . With an O/C ratio increases, CO and Hz reduce significantly. Therefore, under different reaction conditions, iron ore shows significant effects on the reaction rate and the concentration of CO2 and H2 in the biomass chemical looping gasification, and it is of certain significance for the biomass comprehensive utilization.