Analysis and optimization of CO_2 capture in an existing coal-fired power plant in China

摘要

Retrofitting existing power plants for CO_2 capture poses numerous constraints. The layout of the original process and the structure of the existing equipment cause various special problems in the design process as well as influence system performance. In view of these, this paper carries out process simulations, characteristic analysis, and system integration of CO_2 capture based on an existing typical coal-fired power plant in China with supercritical parameters. The main constraints encountered in decarburized retrofitting of the existing power plants using monoethanolamine solution are analyzed. In addition, several special system integration schemes for CO_2 capture in an existing 600 MW power generation unit are put forward. The results reveals that, due to the constraints in the layout of the original process and the structure of the existing equipment, efficiency penalty of CO_2 capture in an existing power plant will be as high as 13.73%-points, higher than a newly redesigned power plant by 3.70%-points. And through special system integrations, the efficiency of such retrofitting existing power plant can increase by 4.15%-points. The research of this paper may provide feasible technology solutions for the decarburized retrofitting of existing power plants and promote CCS (CO_2 capture and storage) technologies into application.