With reference to existing coal fired power plants, two main options for CO{sub}2 capture are viable: post-combustion separation or atmospheric oxy-combustion. Post combustion separation in conventional plants can be very costly because of the relatively dilute concentration of CO{sub}2 in the flue gas. However it presents the advantage that can be easily integrated into existing facilities without relevant modifications. One option to reduce the cost of gas separation is to increase CO{sub}2 concentration in the flue gases by eliminating nitrogen before combustion and by recycling part of the flue gases. Such a scheme is known as oxy-combustion with flue gas recirculation. For future coal-fired plants an alternative technology for CO{sub}2 separation seems to be the pressurized oxy-coal combustion based on the innovative process named ISOTHERM PWR [1]. Among the advantages of the process for CO{sub}2 capture, there are the availability of a pressurized CO{sub}2 stream at boiler's outlet section and the absence of air. This strongly reduces energy penalties associated with CO{sub}2 conditioning imposed by transport requirements. In this paper, starting from a brief description of such a process, the basic design of a 48 MW Pilot -^sPlant, based on this technology, is presented and the related technical choices are discussed.
展开▼
