Q&A - AMINE CIRCULATION

Amine Circulation

Lee:

Mr. Lieberman, which is a better amine – MEA, DEA, or MDEA – for use in a refinery?

Norm:

MEA, without good reclaimer operation, in a plant with an FCU, is going to promote H₂ assisted stress corrosion cracking. MDEA is used in concentrations of 45%, and hence tends to foam. In practice, I have found using 30 – 35 wt.% DEA is optimum – but occasional reclaiming to reduce heat stable salt accumulation is still required. If you have a sulfur plant tail gas scrubber, then a selective solvent, that rejects CO₂ absorption, such as MDEA may be necessary.