A technology for the demercaptanization of light hydrocarbon fractions and liquefied petroleum gas with 25% aqueous ammonia is proposed. One advantage of this method for the demercaptanization of oil fractions over conventional processes such as Merox is the absence of a stage of oxidative catalytic recovery of spent caustic and highly toxic sulfur caustic wastewater. Spent (saturated with sulfur compounds) aqueous ammonia is recovered at the same plant for the distillation of sulfur ammonia wastewater in which aqueous ammonia is produced.

Results of laboratory studies of the extraction of light mercaptans (methyl, ethyl, and propyl mercaptans) from hydrocarbons mixtures with a 25% aqueous solution of ammonia (caustic ammonia) are presented and discussed. It is shown that aqueous ammonia can in principle be used for controlled demercaptanization of light hydrocarbon fractions and liquefied hydrocarbon gases containing hydrogen sulfide and lower mercaptans. The advantage of this demercaptanization method over the conventional processes of alkali treatment is that there is no stage of oxidative catalytic regeneration of a spent alkali and there are no its highly toxic wastes, sulfurousalkaline waste waters. The regeneration of a spent (saturated with sulfurous compounds) aqueous ammonia can be comparatively easily performed by its heating (boiling), which leads to a hydrolytic decomposition of ammonium sulfides and mercaptides to release their constituent gases: hydrogen sulfide, mercaptans, and ammonia. Ammonia is recycled into the process as freshly prepared (regenerated) caustic ammonia.

Processes of methyl and ethyl mercaptan extraction from solutions simulating oil-refinery sulfide alkali waste waters have been studied by distilling argon in the air and atmosphere. In the latter case, the amount of ethyl mercaptan extracted from alkaline solution reaches 94%.

There were presented sources of origin, the amount and composition of sulfur-ammonium wastewater (SAWW) of a modern oil refinery. The necessary local treatment of SAWW is considered as an opportunity of obtain secondary feedstock – hydrogen sulfide and ammonia. Here is discussed, developed and implemented in industry technology of treatment SAWW, that based on the method of rectification and allowing to separate from waste water by separate product streams hydrogen sulfide and ammonia. There was demonstrated that discussed technology in comparison with the simple single-column process of treatment is more ecologically friendly and allowing to create wasteless flow processes.