Is used for demercaptanization of kerosene and diesel distillates, total sulfur content in which does not exceed a norm. DMD-1 process allows decrease mercaptan sulfur content in kerosene below 20 ррm. The process consists in mercaptan oxidation with air oxygen to disulfides over homogeneous IVKAZ catalyst applied to activated carbon./p>
Feedstock (kerosene and diesel fuel) is heated in heat exchanger Н-1 to a temperature of 50–80 оС and enters reactor R-1. Before the reactor inlet an estimated quantity of air is injected into the feedstock via efficient distributor. Oxidation of mercaptans proceeds in the reactor at a temperature of 60–80 оС and a pressure of 0.5–1.5 MPa over the catalyst following a reaction:/p>
2 RSH + 0.5 O2 RSSR + H2O
The demercaptanized feedstock together with the spent air is discharged from the reactor bottom and sent via air cooler С-1 to settler V-1 to be settled from reaction water, then to salt filter V-2 for moisture removal and to adsorber А-1 for removal of resinous substances traces. The dissolved air (5–10 % of oxygen and 90–95 % of nitrogen) is separated at pressure reduction in storage tanks of finished products./p>
The DMD-1 process for aviation kerosene treatment was commissioned on Kuibyshev refinery (capacity of the plant is 310 000 t/yr) and Ukhta refinery (capacity of the plant is 50 000 t/yr).
DMD-1 process flow diagram