Thermodynamic analysis of integrated sorption-enhanced staged-gasification of biomass and in-situ CO2 utilization by methane reforming process based on calcium looping
Chunxiao Zhang, Yingjie Li, Zhiwei Chu, Yi Fang
Abstract
Sorption-enhanced H 2 production using CaO promotes H 2 generation by capturing CO 2 in the form of CaCO 3 . Coupling methane reforming of CaCO 3 in sorption-enhanced H 2 production combines CaO regeneration with in-situ CO 2 utilization. This integrated concept is expected to achieve high H 2 production with CO 2 capture and in-situ conversion into syngas. To evaluate the overall performance of the integrated sorption-enhanced staged-gasification of biomass and in-situ CO 2 utilization by methane reforming process, the thermodynamic simulation was performed using Aspen Plus. The parameter optimization of the integrated process was carried out. The performance of the integrated process was also compared with two other processes, such as the serial sorption-enhanced staged-gasification and methane reforming process and the standalone sorption-enhanced staged-gasification process. The results exhibit that integrated methane reforming enhances H 2 production from sorption-enhanced staged-gasification, because it can lower the CaO regeneration temperature and enhance the CO 2 capture capacity. The integrated process produces a total gas product with H 2 /CO around 2, which is suitable for direct Fischer-Tropsch synthesis. Compared with the serial sorption-enhanced staged-gasification and methane reforming process, the integrated process results in 73.5% less CO 2 emission and 135% more CO 2 utilization. Moreover, the integrated process exhibits the higher energy conversion and exergy efficiencies than two other processes, which are as high as 74.5% and 68.6%, respectively. This work shows that the integrated process has technical and environmental potential for the utilization of biomass and CH 4 to produce H 2 and syngas with CO 2 capture and in-situ utilization.