Preparation of high pure naphthenic acids

A new industrialized process giving high pure naphthenic acids refining from crude naphthenic acids has been proposed in this paper.The title process giving naphthenic acids with higher acid value involves treating crude naphthenic acids with caustic soda,removing water,the neutral oils and the materials that are not formed into the acid salts.The naphthenic salt mixture is then acidified to recover the naphthenic acids which is then distilled undeer reduced pressure.The acid content of finished product can reach 98% and the rare of recovery of acid number beyond 90%.That factors such as temperature, vacuum were studied on the production equipment of 500 t/a commercial scale, and its economic evaluation was briefly investigated.The technology was applied in seven domestic units.The economic and social effectiveness have been attained significantly.1fig.,6tabs.,6refs.