Abstract: A process for petroleum refining to obtain petroleum products having a reduced content of sulphur, oxygen-and nitrogen-containing compounds which comprises introducing into the petroleum during distillation volatile and nonvolatile carbonyl compounds of transition metals selected from the group consisting of Cr, V, Mo, W, Mn, Re, Fe, Co, Ni in amounts of from 0.02 to 0.2% by weight of the petroleum at a temperature ranging from 150.degree. to 350.degree. C under a pressure of from 1 to 7 atm abs. and distilling the petroleum into the desired products.Gasoline and kerosene resulting from such processing have a 5 to 10 times reduced content of mercaptan sulphur and 2 to 10 times reduced total sulphur content, as well as a reduced content of gums.