Supercritical CO₂ cycle for coal-fired power plant based on calcium looping combustion

Calcium looping combustion (CaLC), which comprises an indirectly-heated calciner, is characterised with lower energy intensity and economic penalties compared to that of mature CO₂ capture technologies. As CaLC is a standalone power boiler, integration of advanced power cycles can lead to further improvement in net efficiency and reduction in the cost of electricity. Therefore, this study aimed to propose routes for the integration of the supercritical CO₂ cycle (sCO₂) with CaLC and to evaluate their benefits with respect to the conventional steam cycle. Such processes were modelled in Aspen Plus™. Moreover, the effect of the operating conditions on the techno-economic performance of the considered cases was evaluated. This study has shown that implementation of the optimised recompression sCO₂ cycle with a clean gas cooler resulted in the net efficiency and break-even price of electricity of 37.3%_HHV and 75.13 €/MWh, respectively. These are 0.7%_HHV points lower and 26% higher, respectively, than that of the conventional coal-fired power plant without CO₂ capture. Such performance, however, is superior to retrofits of coal-fired power plants with mature CO₂ capture technologies as well as CaLC with a conventional steam cycle, proving the benefits of linking CaLC with advanced power cycles.