Post-combustion CO2 capture applied to a state-of-the-art coal-fired power plant—The influence of dynamic process conditions

Abstract

A dynamic model of the amine-based CO2-capture process is presented and applied to investigate the transient behavior of the absorption system during and after load changes in Nordjyllandsværket, a state-of-the-art coal-fired power plant with a thermal efficiency of 47.5%. Two scenarios of flexible operation in the power plant are investigated: part-load and peak load operation. Simulations of the load-variation scenarios show that implementation of active control strategies improves capture system performance with respect to capture efficiency and the heat requirement. The reboiler duty can be decreased considerably during part load operation compared to a case where no control strategy is applied. Integration of the capture process with the power plant results in an efficiency decrease of around 9 percentage points at full load and in the range of 8–12 percentage points during 60% part load operation, depending on if a process controller is used or not. Energy requirement for CO2 compression is not included in these numbers. In addition, the response time of the absorption system is significantly decreased in the cases where a process control strategy is implemented, both for part load and peak load operation.