Characteristics and economic evaluation of CO2‐capturing power generation systems using solar thermal energy and gasified coal

Abstract

AbstractThis paper describes the evaluation results of CO2‐capturing power generation systems which use solar thermal energy and gasified coal as the input energy. The following two power generation systems have been proposed and evaluated from the characteristic and economic points of view: a CO2‐capturing hybrid power generation system (proposed system I), and a CO2‐capturing three‐stage heat‐utilizing power generation system (proposed system II). In evaluation, a conventional integrated coal‐gasification combined cycle power generation system (IGCC system) is adopted as the reference system. The proposed systems are assumed to be constructed in Albuquerque, U.S. and Osaka, Japan. The net coal‐to‐electricity efficiency has been estimated to be 51.0% for the proposed system I, and to be 40.1% for the proposed system II on higher heating value basis, whereas the efficiency of the conventional system is estimated to decrease from 43.7% to 32.7% when the CO2 generated is captured. Taking the IGCC system without CO2 capture as the reference system, the cost of CO2 emission reduction of the proposed systems I and II in Albuquerque are estimated to be 22,100–23,800 yen/t‐C and 21,800–23,000 yen/t‐C, respectively, and that in Osaka to be 37,000–38,700 yen/t‐C and 23,300–24,500 yen/t‐C, respectively. It has been shown that these are lower than the cost of CO2 emission reduction of the IGCC system with CO2 capture by 43,800–48,400 yen/t‐C. © 2001 Scripta Technica, Electr Eng Jpn, 138(1): 1–13, 2002