Today among the new processes included are the use of sterically hindered amines for H2S and CO2 absorption.
MDEA is a tertiary amine which is widly used in recent designs. Less capital cost, less operating cost, and ease of operation are the main factors.
However, the old plants which were designed based on other amines could be changed to MDEA based solvents. These are solvents which contains MDEA as base solvents plus other amines in mixture. The reason for that depends to the treated gas requirment.
Such a work has been done and the results are published in Oil & Gas Journal Nov.2000 pp.60-61.
The result of that work has been reported satisfactory.