生物质化学链气化多联产工艺热力学分析

Thermodynamic Analysis of Polygeneration Process based on Biomass Chemical Looping Gasification

为提高生物质的利用效率,提出了生物质化学链气化氢-电-甲醇多联产工艺,采用CaO吸附强化Fe2O3生物质化学链气化过程,生产高纯度氢气和适用于甲醇合成的高氢碳比合成气。选用木屑作为生物质,利用Aspen Plus软件进行过程模拟和热力学分析,以合成气的氢碳比(H/C)、系统氢气效率、净电效率、甲醇效率和总效率作为评价指标,讨论了水蒸气与生物质质量比(S/B)、氧载体与生物质质量比(MCa/B、MFe/B)和气化压力(pCLG)对系统性能的影响。结果表明:在S/B=0.4、MCa/B=1、MFe/B=0.5和pCLG=0.8 MPa时,系统性能最优,合成气的H/C为2.09,甲醇效率为41.28%,总效率为59.34%。

To improve the utilization efficiency of biomass,a hydrogen-power-methanol polygeneration process based on biomass chemical looping gasification was proposed.The integrated sorption enhanced biomass chemical looping gasification and water splitting process was employed to produce hydrogen and hydrogen-rich syngas using iron oxide(Fe2O3) as an oxygen carrier and calcium oxide(CaO) as a carbon dioxide(CO2) adsorbent.Wood chips were selected as biomass,and process simulation and thermodynamic analysis were carried out using Aspen Plus software.The effect of operation parameters on system performances were investigated,including the ratios of steam to biomass(S/B) and oxygen carrier to biomass(MCa/B,MFe/B) and gasification pressure(pCLG).The evaluation index included the hydrogen to carbon ratio(H/C) of syngas,hydrogen efficiency,net power efficiency,methanol efficiency and total energy efficiency.The system parameters were optimized with the highest energy efficiency.The results showed that H/C of 2.09 for syngas,methanol efficiency of 41.28% and total energy efficiency of 59.34% were obtained under the optimized condition(S/B=0.4,MCa/B=1,MFe/B=0.5 and pCLG=0.8 MPa).