Modeling and Evaluation of Biomass-Based Chemical Looping Gasification-Integrated Power Generation Cycles with Focus on Energy and Exergy Analyses and Solar Energy Application

A biomass-based chemical looping gasification-integrated power generation cycle model that combines biomass chemical looping gasification (BCLG) and an integrated gasification combined cycle (IGCC) was established using Aspen Plus software. The reliability of the proposed model was verified according to the experimental data. The exergy balance of the BCLG process was analyzed in detail, and the exergy efficiency of the chemical looping gasification process of pine sawdust, rice stalk, and corn stalk was compared. The influence of the main operating conditions, such as the gasification temperature, oxygen-to-biomass ratio (lambda), and steam-to-biomass ratio (S/B), on BCLG progress was investigated when the whole system was researched at the steady state. The results indicate that the optimal operating conditions were a gasification temperature of 850 degrees C, a lambda of 0.1, and an S/B of 0.4, the heat balance could be maintained, and the system could achieve higher energy efficiency and exergy efficiency, which were 44.74 and 40.37%, respectively. In addition, the BCLG-IGCC system coupled solar energy under two frameworks was studied and analyzed. Solar energy was used to provide the heat for the compressed air for the gas turbine or produce additional steam to supply the low-pressure steam turbine for power generation. Among the above two, using solar energy to heat compressed air for the gas turbine was a better way to use solar energy.