We have been experiencing intermittent DMDS formation across our LPG amine contactor in FCCU gas plant the DMDS this ends up inhibiting downstream units. Anyone else seen this?
Typically we see 0-2ppm DMDS in the feed to the LPG amine contactor it increases then to 10-20ppm on the outlet with a drop in the methyl mercaptan which is close to the stoichiometric ratio. This is the first aqueous system that the LPG contacts and all the precursors are present except for oxygen (well as far as we can detect). We have changed the amine make up water to condensate and insured the nitrogen blankets on the amine surge drums are working. We just can’t nail down the cause as its intermittent it affects our selective hydrogenation unit and increases the ASO make from the alkylation unit.
If anyone else has experienced this would be willing to share information.
The original message is posted by Gareth Richardson from MurphyOil at