2 replies to this topic

[aanita]

In a gas sweetening plant using MDEA solvent, I want to know the Regenarator optimum top and bottom temperature, Reflux ratio, Reboiler heat load. Also H2S content in regenerated amine( lean amine) in corrosion point of view. Is there any thumb rule so that I can have a quick calculations. MDEA is 45 % on weight basis, a rich amine loading of 0.6 mol/mol and a lean amine loading is 0.004 mol/mol are currnetly maintaining.
Currently our H2S in lean amine is ~ 70 to 85 ppm. We want to maintain ~ 100 ppm on corrosion point of view.
Your helps are more appreciated.

Regards.

[rosa]

aanita,

In Campbell book you can find some rules of thum in this regard.Just FYI in our gas plant gas flow per train is 500 MMSCFD IN sweetening unit with MDEA solent .top regenerator temp is 106 °C and bottem temp(reboiler temp) is 127°C.with 9-11 m3/h reflux ratio.The maximum h2s loading of lean should be less than 86 ppmw.but actually in our sweetening unit it is around 15 ppmw.

cheers!
rosa

[aanita]

And what about corrosion rate in the piping system.
I agree 115 ppm H2S is no problem. What should be the lowest H2S content in
lean amine, H2S in amine will form a ironsulfide protective layer in the piping to
prevent further corrosion. Even in our plant ( 500 MMSCFD gas flow), H2S in lean amine is 145~ 165 ppm without any considerable corrosion rate. However reflux ratio and steam in reboiler is still not matching.

Regards.