Macroscopic model-based design and techno-economic assessment of a 300 MWth in-situ gasification chemical looping combustion plant for power generation and CO2 capture

The in-situ gasification chemical looping combustion (iG-CLC) is a potential combustion technology for solid fuels that facilitates CO2 separation process. In this study, A 300 MWth iG-CLC unit has been designed for combustion of bituminous coal with ilmenite oxygen carrier, and integrated with a subcritical steam cycle for power generation. The reactor system was modeled by employing mass and energy balances as well as a macroscopic model for fuel reactor that has been adapted for fluid dynamics of large-scale circulating fluidized beds. The developed model was used to predict CO2 capture efficiency and analyze the effect of key operating parameters of the unit, namely, composition of fluidizing gas, reactor temperature, solid inventory and particle size. Achieving the CO2 capture efficiency of 85% with a carbon stripper efficiency of 98% leads to a net thermal efficiency of 37.94% and a levelized cost of electricity (LCOE) about 98.082 $/MWh. Use of a higher-efficiency carbon stripper or more reactive fuels is recommended to obtain greater capture rates more economically. Nonetheless, at 90% CO2 capture efficiency, the designed iG-CLC plant has 3.74% higher net thermal efficiency and 4.827 $/MWh lower LCOE than the conventional post-combustionCO(2) capture technology integrated with a coal-fired power plant.

Automated summary

A 300 MWth iG-CLC unit was designed for solid fuel combustion and CO2 separation process. The study analyzed the impact of operating parameters on the unit's performance and found that controlling gas composition, reactor temperature, solid inventory, and particle size can lead to high CO2 capture efficiency and power generation.