Development of multimode gas-fired combined-cycle chemical-looping combustion-based power plant layouts.

Operation of power plants with carbon dioxide capture and sequestration (CCS) and without carbon dioxide capture and storage modes and energy penalty or energy utilization in such operations is of great significance. This work reports on two gas-fired pressurized chemical-looping combustion (CLC) power plant layouts with two inbuilt modes of flue gas exit, namely, one with carbon dioxide capture mode and the second mode is letting flue gas (consists of carbon dioxide and water) without capturing carbon dioxide. Without CCS mode, the higher thermal efficiencies of 54.06 and 52.63% are obtained for natural gas and syngas, respectively. In carbon capture mode, a net thermal efficiency of 52.13% is obtained with natural gas and 48.78% with syngas. The operating pressure of the air reactor is taken to be 13 bar for realistic operational considerations, and that of the fuel reactor is 11.5 bar. Two power plant layouts were developed based on combined-cycle chemical-looping combustion (CC CLC) for natural gas and syngas fuels. A single layout is developed for two fuels with a possible retrofit for dual fuel operation. The CLC power plants can be operated with two modes of flue gas exit options, and these operational options make them higher thermal efficient power plants.