DMC-1MA process for oil treatment for hydrogen sulfide

The most efficient and energy-conserving process for treating oil with high hydrogen sulfide content is liquid-phase oxidation using aqueous-ammonia solutions of IVKAZ catalyst following reactions:

H2 S + NH4OH → NH4SH + H2O

NH4SH + 0,5 O2 → S° + NH4OH


2 NH4RS + 0,5 O2 → RSSR + 2 NH4OH

Hydrogen sulfide is oxidized to elemental sulfur and C1-C2 mercaptans (methyl- and ethyl mercaptans) are oxidized to disulfides. The process is carried out at a pressure of 4-10 bar and a temperature of 30-60 0С. Consumption of the catalyst complex solution is ~ 1-2 l/t of feed.

The aqueous ammonia solution of catalyst complex (CC) is prepared in vessel V-1. The stabilized oil is sent with pumps via mixer M-1 to oxidation reactor R-1. Compressed air from a compressor and the CC are supplied with dosing pump PD-1 to mixer M-1. The CC and process air consumption are set proportionally to oil consumption and to sulfur compounds content in the oil. The mixture of the oil and the CC, containing the dissolved air, enters reactor R-1.

Then the mixture of the oil and the CC, containing the dissolved spent air, is sent to settling separator V-2. At a pressure decrease in V-2 the separated spent air with admixed light hydrocarbon gases is sent to a flare. The treated oil is sent with pump to oil tanks. The separated CC is returned from V-2 as a recycle into the oxidation reactor.

The DМС-1МА process was tested successfully in 2012 on “Nurlatneft” plant of PJS “Тatneft”. The plant capacity is 150 m3/hr. Hydrogen sulfide content in the feed is 350-530 ppm, while in the treated oil it is below 10 ppm.

The DMC-1MA process flow diagram