Thermodynamic, energy level and economic evaluation of biomass chemical looping gasification multi-generation system with phase-change separation carbon capture and storage

Abstract

Biomass chemical looping gasification (BCLG) could enable cleaner biomass utilization and provide advantages for carbon capture and storage (CCS) of the syngas. This work investigates a novel multi-generation system that combines the BCLG system, water gas shift (WGS) system, CCS system with phase-change separation (PCS) technology, and organic Rankine flash cycle (ORFC). The high-quality steam from the BCLG system is used to regenerate biphasic solution, medium-temperature liquids generate electricity, and low-quality liquids supply domestic hot water. Based on the energy, exergy, and economic analysis, the proposed system is compared with the reference system. Then, the key components of high energy consumption and exergy destruction are analyzed using the energy utilization diagram (EUD) method based on the emergy evaluation. Finally, the sensitivity analysis is performed. The energy efficiency of the proposed system is 57.51% and 11.51% higher than the reference system. The levelized cost of energy and the payback period of the multi-generation system are 24.2 $/MWh and 6.61 years, respectively. The EUD results show that the heat absorption of pyrolysis and gasification for the FR is 7.4 MW lower than that of the traditional gasification. Due to the high energy level of the oxygen carrier, the exergy destruction of the FR is highest (56.1 MW). For the CCS-PCS system, the total energy demand for heating the biphasic solution is 45.4% lower than that of the traditional CCS system. The levelized cost of energy and payback period decreases and then increases with the increase of the FR temperature.