Reaction of acid gases with mixtures of amines

Detailed thermodynamic and kinetic models are presented in this paper which were developed for acid gas reactions with mixtures of amines. The models permit the extension of the nonequilibrium-stage approach in the simulation of gas treating plants using solvent blends. The prediction of these models indicate a potentially great improvement in sour gas treating processes. The mixing concept enables one to obtain the individual advantages of each amine for absorption as well as desorption without the disadvantages of either. In the absorber, the MEA in the blend at the top of the column serves to remove residual CO2 from the gas while throughout the rest of the column MDEA does a bulk removal job. The use of blended amines to treat natural, refinery and synthesis gases brings about a considerable improvement in absorption and a great savings in energy requirements.