Refining Process - Hydrorefining

Hydrorefining is under the working of hydrogen pressure and catalyst, to remove hydrogen sulfide, water and ammonia which transformed by oxygen, nitrogen and sulfur etc harmful impurities in the oil.

At the same time, make the olefin and diolefin get saturated by hydrogenation and make aromatic get saturated by hydrogenation then to improve the quality of oil products. 

Sometimes, hydrorefining refers to the refin and modification of light oil, and hydrotreating refers to refin and desulphurization of heavy oil.