Continuous hydrogenation of methyl ricinoleate using Ni/AL[subscript 2]O[subscript 3] catalyst

Abstract

The continuous hydrogenation of methyl ricinoleate, which prepared by transesterification of castor oil with methanol, using in-house continuous tubular reactor was investigated. The nickel on alumina support catalyst was used at different percents of nickel per support such as 10%, 15% and 20%. The operating conditions, including reaction temperature and hydrogen pressure were studied. It was found that the best efficient catalyst to produce methyl 12-hydroxystearate was 15% nickel on alumina. The suitable conditions were at reaction temperature 120 ℃, hydrogen/nitrogen pressure 20 psig. The product obtained under this condition had iodine value 1.18 and melting point 49 ℃, consisting of 7.69% methyl stearate and 92.04% methyl 12-hydroxystearate. Meanwhile, methyl oleate and methyl linoleate were completely hydrogenated. The continuous hydrogenation in a tubular reactor using 15% nickel catalyst provided the highest amount of methyl 12-hydroxystearate in the hydrogenated products compared with other catalysts under optimum conditions.