双流化床生物质气化及CO2捕获的模拟

摘要

用Aspen Plus建立了双流化床气化和燃烧模型,对生物质在双流化床中气化及CaO吸收合成气中的CO2过程进行了模拟研究；探讨不同反应条件:气化温度、蒸汽与生物质的质量配比(S/B)以及CaO循环量与生物质的质量配比(Ca/B)对合成气成分的影响,为该类型工业反应器的研发提供了理论依据.模拟分析结果表明:气化温度低于700℃时,CaO能很好地吸收气化过程中产生的CO2并促进平衡反应向产氢方向进行;在温度为650℃及CaO作用下,S/B在0.6～1.7内对合成气成分的影响不大；CaO的加入能够有效地改善合成气的组成,合成气中氢气浓度能达到95％以上,氢气产量达到52 mol/kg.%An Aspen model was built to simulate the gasification and combustion processes in the dual fluidized beds. The processes of biomass gasification and CO2 adsorption by CaO were stud-ied.The effects of gasification temperature, biomass ratio to steam (S/B), CaO to biomass ratio (Ca/B) on the syngas composition were discussed. Simulation results indicated that CaO can effectively capture the CO2 in the syngas and shift the thermodynamics balance to hydrogen production direction when the gasification temperature was below 700 X.. Steam to biomass ratio (0.6-1.7) has very little influences on the syn-gas composition under the gasification temperature of 650 ℃ and with the existence of CaO. The addition and circulation of CaO can effectively improve the syngas composition. The hydrogen concentration in the syngas can reach up to 95% and hydrogen production rate reach 52 mol/kg.