Open-loop step responses for the MEA post-combustion capture process: Experimental results from the Esbjerg pilot plant

Abstract

Abstract Amine based post-combustion capture is seen as one promising technology for future coal fired power plants with CO2 capture. The coupled absorption/desorption system to remove the CO2 from the flue gas is highly integrated with the power plant and the downstream CO2 compression, transportation and storage. With increasing portion of alternative energy forms like e.g. wind power, the demand on modern coal-fired power plants to provide regulating net power is increasing, leading to frequent and fast load changes during operation. To make the implementation of CCS to these plants technically and economically feasible, the capture process has to be able to follow these fast load changes without restraining the overall plant performance. To investigate the transient behavior of the individual plant components, as well as the overall dynamic performance of the capture unit, step response tests have been performed at a 1 ton CO2/hour pilot plant for the amine-based post-combustion process within the EU project CESAR. The purpose of the tests was to gain knowledge about possible problems or bottlenecks during a dynamic operation where the plant is going from one operation point to another. Three operation parameters were changed stepwise and the response of the entire system was monitored. In this paper the results of the tests are shown and the response of the system is analyzed. In general, no unexpected observations were made and no bottlenecks were found during the step response tests performed. The overall system acts like a buffer for any perturbation at the inlet, which is a wanted effect considering the future downstream compression unit. The average time for the entire system to reach the new steady state operating conditions after the perturbation was between 1 h 15 min and 1 h 45 min. However the interaction of the coupled absorber/desorber system led to fluctuations in the system, when all parameters have been changed simultaneously.