COMPARATIVE EVALUATION OF OXY-COAL POWER GENERATION SYSTEMS

A systematic evaluation of design alternatives for oxy-coal power generating plant with carbon dioxide capture and storage (CCS) capability is presented. This study is performed along with the retrofitting attempt of the existing 125MWe coal firing power station of Young-Dong (YD) station of Korea South-East Electric Power Company. Evaluation cases are selected for comparison, namely the base case of original plant, a case of retrofitted boiler with existing steam-power generation block, a case of optimized oxy-PC power plant. Comparative evaluation is based on the system of individual blocks, including air-gas block, water-steam side block, air separation unit (ASU) and carbon dioxide process unit (CPU) blocks. A system of independent blocks as well as a system of cross-linked blocks is considered. Thermodynamic analysis included the thermal efficiency to power generation, the exergy analysis based on the second law and sensitivity analysis to impurities in the system including the purity of oxygen, air ingress into the oxygen-combustor, and unwanted gaseous components of nitrogen, argon and oxygen in ASU and CPU.