System simulation and experimental verification: Biomass-based integrated gasification combined cycle (BIGCC) coupling with chemical looping gasification (CLG) for power generation

Abstract

Biomass-based integrated gasification combined cycle (BIGCC) is a power generation technology to convert biomass fuel to electricity. In view of biomass gasification characteristic, chemical looping gasification (CLG) is an innovative biomass utilization technology. Due to the presence of metal oxygen carrier materials in CLG process, syngas yield can be increased and tar catalytic cracking is occurred. In this paper, a new system integrating BIGCC with CLG is designed for power generation and the simulation of the whole process, including biomass gasification, gas cleaning, heat recovery steam generator (HRSG) and gas/steam turbine, are carried out with Aspen Plus software. At first, in order to ensure the model accuracy, the experiments in a 25 kWth reactor of interconnected fluidized beds are conducted and the experiment results are compared with the simulated results from the designed model. It is verified that the designed biomass gasification model, especially kinetic model and equilibrium model, is accurate with the change of gasification temperature and steam-to-biomass (S/B) ratio, which enhances the reliability of the whole CLG-BIGCC system. The CLG-BIGCC system exhibits a better plant performance, where power efficiency is higher than the ones in the existing BIGCC demonstration plants. The sensitivity analysis on the CLG-BIGCC system is also discussed. Results indicate that optimal gasification temperature is 860 °C and most suitable S/B ratio was 1.0. Besides, five optimization schemes about CLG-BIGCC with nitrogen reinjection are proposed and investigated.