Improvements relating to the preparation of catalysts for the refining of lubricating oils and to the use of such catalysts in such refining

摘要

In the preparation of catalyst compositions activated calcined alumina is impregnated with a non-alkaline solution of ferric nitrate, dried and calcined, and thereafter further impregnated with an ammoniacal solution of ammonium molybdate, dried and calcined. The further impregnation may be effected with a solution which additionally contains cobalt nitrate, or after impregnating with ammoniacal ammonium molybdate solution, drying and calcining, the alumina may be treated with a separate solution of cobalt nitrate followed by drying and calcining. Preferably the activated alumina is g -alumina. The final composition of impregnants on alumina may be 3-20% molybdena, 4-20% ferric oxide and 1-12% cobalt oxide. The source of alumina is preferably hydrargillite which has been calcined at above 500 DEG C. to produce an alumina having a surface area of 250 square metres/gram, pores of 30 , and pore volume of 35 cubic metres/gram. The catalyst may be used in refining lubricating oil, e.g. by contacting the oil in the presence of hydrogen and at a temperature below 340 DEG C. with a catalyst as prepared above. Prior to its contact with oil the catalyst may be activated by contact in the presence of hydrogen with a sulphur-containing mineral oil at a temperature of at least 300 DEG C. for at least 24 hours. Suitable catalytic refining conditions are:-catalyst/oil contact temperature 150 DEG -340 DEG C., hydrogen pressure 5-70 atmospheres, hydrogen feed rate 3-150 vols. per vol. of oil treated and space velocity from 0,5-6,0 vols. of oil per vol. of catalyst. Examples are given.