1 reply to this topic

[ishams]

Hi there, I am new in this forum. Well, as a start, I would like somebody to help me on the gas treating process. My case is for MDEA solvent type at 68 bar@75 DegC. The question is what will be the effects that may occur if the absorber column is operated at lower pressure ~60 bar. Thank you in advance.

[Zauberberg]

Lower absorber pressure shifts reaction equilibrium towards lower solubility of acid gases, so you'll need higher solvent circulation rate in order to maintain sweet gas quality. This also means you have to account for higher MDEA regeneration requirements, chemical and water make-up rate, and the pumping cost.

There is a generic-type chart for all chemical solvents where you can observe how solvent equilibrium loading increases with acid gas partial pressure, up to the point where increasing system pressure is not any more beneficial in terms of amine circulation rate reduction. From that point, use of physical or combined solvents starts to be much more attractive. However a caution is required, because we don't know acid gas removal requirements in your case, preferred selectivity of CO2/H2S etc.

If you can get a book "Gas purification" by Kohl & Nielsen, you'll find there many precious information and references.

Best regards,