Techno-economic investigation of a chemical looping combustion based power plant

Abstract

Among the well-known state-of-the-art technologies for CO₂ capture, Chemical Looping Combustion (CLC) stands out for its potential to capture CO₂ efficiently from a fuel power plant. CLC involves the combustion of carbonaceous fuel such as coal-derived syngas or natural gas via a redox chemical reaction with a solid oxygen carrier circulating between two fluidised beds. Avoided NO_x emissions, high CO₂ capture and thermal efficiency are the key concepts that make worth the investigation of this technology. One of the main issues about CLC might concern the impact of the solid metal oxides price and lifetime on the Levelised Cost Of the Electricity (LCOE). A natural gas fired power plant embedding a CLC unit is presented in this work. Detailed fluidised bed models are implemented in Aspen Plus software. Kinetics and hydrodynamics are taken into account to evaluate their effect on the total solid inventory required for full fuel conversion. The models are incorporated into a power plant and a detailed economic evaluation is undertaken by varying two relevant parameters: fuel price and lifetime of the solid particles. The effect of these parameters on the LCOE is investigated and a comparison between CLC and a post-combustion technology employing amines (e.g. monoethanolamine, MEA) is presented. It is shown that the CLC power plant under study leads to a lower LCOE compared to the current MEA post-combustion solution.