Performance evaluation of an oxy-coal-fired power generation system : thermodynamic evaluation of power cycle

Abstract

Power generation systems based on the oxy-coal combustion with carbon dioxide capture and storage (CCS) capability are being proposed and discussed lately. Although a large number of lab scale studies for oxy-coal power plant have been made, studies of pilot scale or commercial scale power plant are not enough. Only a few publicized demonstration projects for oxy-coal power plant are introduced recently. The proposed systems are evolving and various alternatives are to be comparatively evaluated. This paper presents a proposed approach for performance evaluation of a commercial 100MWe class power plant, which is currently being considered for ‘retrofitting’ for the demonstration of the concept. The system is configurated based on design-operating conditions and proper assumptions. System components to be included in the discussion are listed. Part division and methods are suggested as an approach for system configuration and for verifying main variables. Evaluation criteria in terms of performance are summarized based on the system heat and mass balance and simple performance parameters, such as the fuel to power efficiency and brief introduction of the second law analysis. Also gas composition is identified for additional analysis to impurities in the system including the purity of oxygen and unwanted gaseous components of nitrogen, argon and oxygen in air separation unit and $CO_2$ processing unit. Cases are selected for comparative evaluation, based on the site-specific requirements. With limited information available, preliminary evaluation is attempted for the cases.