Research On Coal-fired Power Plant With CO₂ Capture By Integrating MCFC System

Nowadays, with the rapid development of technologies, people’s demand of energy becomes higher, and the environmental pollutions become much more serious. The carbon dioxide emission problem which is the main cause of the greenhouse effect has caused all countries’attention. It’s the most efficient way to reduce CO2 emissions of conventional power generation technologies as it’s the main source. In this paper the coal-fired power plant with CO2 capture by integrating molten carbonate fuel cell (MCFC) system is proposed based on the coal-fired power plant without CO2 capture. With the Aspen Plus software, the model of hybrid systems are established and the key parameters such as efficiency and CO2 capture rate are studied. The hybrid systems can be used to solve the problems of CO2 emissions with guaranteeing the high efficiency.Firstly, this paper introduced the Aspen Plus software and the model of MCFC was established and simulated based on the reaction and mathematics principles with it. The coal-fired power plant with CO2 capture by integrating MCFC system was introduced. By comparing with the coal-fired power plant without CO2 capture benchmark system and analyzing key parameters, the results show that the hybrid system has obvious advantages on system efficiency and CO2 capture rate.Secondly, this paper introduced the operating principle of oxygen ion transfer membrane (OTM) and proposed two different hybrid systems with CO2 capture by integrating MCFC and OTM. One hybrid system is the coal-fired power plant substituting low-pressure heaters with CO2 capture by integrating MCFC system and OTM. The feed water of boiler was heated by the high temperature exhaust gas of MCFC in heat exchangers which were used to replace low-pressure heaters. The other hybrid system is the coal-fired power plant reheating the intermediate pressure turbine steam with CO2 capture by integrating MCFC system and OTM. One part of intermediate pressure turbine steam was reheated by the high temperature gas of MCFC and produced power in the additional low-pressure turbine. The results of two different hybrid systems were compared with the benchmark system, and the influence of key parameters to hybrid systems were analyzed. The hybrid systems have obvious advantages on efficiency and cascade utilization of energy.Achievements in this paper will provide the theoretical basis on the coal-fired power plant by integrating MCFC system designing and the valuable reference for CO2 capture of coal-fired power plant with low energy consumption.