Comparative analysis of the efficiency penalty in power plants of different amine-based solvents for CO2 capture

Abstract

Amine solvents are one of the main options for post-combustion CO2 capture applications. The main drawback of the carbon capture processes is the required energy to regenerate the solvent once it has reacted with the CO2. When applied to a power plant, the energy requirement has an important impact on the net efficiency of the overall system. Several solvents, i.e., monoethanolamine (MEA), diethanolamine (DEA), methyl diethanolamine (MDEA), and many others have been proposed to overcome this drawback. Regeneration temperature and heat duty reduction are considered to be the significant objectives. Moreover, enhancement of the amine’s concentration and its working capacity without the impact on the other variables are important. In this work, different types of amines with a wide range of heat duty and regeneration temperatures under the same set of assumptions are calculated and compared. The effect of both variables on the energy penalty caused by carbon capture is measured. A review of amines and their effects on the net efficiency of the overall system (power plant, chemical absorption, CO2 compression) are conducted and analyzed. As expected, the impact of heat duty is greater than the modification of regeneration temperature. The effect of reducing 1 GJ/ton CO2 in the heat duty is similar to the effect of reducing the regeneration temperature from 40 °C to 25 °C.