Carbon dioxide removal from flue gas using hybrid solvent absorption

Abstract

Normally, flue gas released into the atmosphere from most industries, including the petrochemical industry, contains approximately 80 % N2, 15 % CO2, and 5 % O2. The flue gas produced by the combustion of fossil fuels, which is composed of CO2, is therefore considered to cause the greenhouse effect. To reduce greenhouse gas emission, the liquid solvent absorption process, the most important commercial technology for CO2 removal, can be efficiently applied. The widely used solvent is monoethanolamine (MEA). Sterically hindered amines and diamines have also been introduced because of their advantages in high absorption capacity and high degradation resistance. Hence, the aim of this work was to investigate hybrid solvents blended between MEA and other amine additives. The experimental results showed that the MEA aqueous solvent with MEA concentration of 30 wt.% provided the maximum CO2 removal efficiency, as well as high CO2 absorption rate and CO2 loading capacity. When MEA was blended with a suitable amine additive at an appropriate blending ratio, both the absorption rate and CO2 loading capacity tended to increase.