Technoeconomic Analysis of a Fixed Bed System for Single/Two–Stage Chemical Looping Combustion

Abstract

Chemical looping combustion (CLC) is a promising carbon capture technology allowing integration with high-efficiency Brayton cycles for energy production and yielding a concentrated CO2 stream without requiring air separation units. Recently, dynamically operated fixed bed reactors have been proposed and investigated for CLC. This study deals with the technoeconomic assessment of a CLC process performed in packed beds. Following a previously published work on the topic, two different configurations are considered: one relying on a single oxygen carrier (Cu/CuO based) and the other on two in–series oxygen carriers (Cu/CuO based first, Ni/NiO based later). For both configurations, relevant process schemes are devised to obtain continuous power generation. Despite slightly larger capital costs, two-stage CLC performs better in terms of efficiency, levelized cost of electricity, and avoided CO2 costs. Fuel price and high–temperature valves costs are identified as the main variables influencing the economic performance. The use of two in–parallel packed bed reactors (2.0 m length, 0.7 m internal diameter) enables a power output of 386 kWe, a net electric efficiency of 37.2%, a levelized cost of electricity of 91 € MWhe−1, and avoided CO2 costs of 55 € tonCO2−1 with respect to a reference pulverized coal power plant.