Multi-functional heat pumps integration in power plants for CO2 capture and sequestration

Amine absorption is a common method for CO2 removal from flue gas of a power plant. The heat of regeneration, which is usually provided by steam extracted from the power cycle, reduces the power plant efficiency. In this paper, seven configurations of heat pumps integrated with CO2 capture plant of a natural gas combined cycle (NGCC) power plant were evaluated using HYSYS software. The heat pump provides the regeneration heat as well as processes heating and cooling. Forty-one working fluids were investigated, and the most promising ones were R-141b and NH3, with as much as 3.1% savings in the efficiency. When the heat pump cooling and heating capacities were to be considered in the efficiency calculations, the enhancement in efficiency becomes as high as 13.6%.