| The fatty acid butyl ester was respectively synthesized by the esterification of oleic acid with butanol and the transesterification of rapeseed oil with butanol catalyzed by amino sulfonic acid. The fatty acid butyl ester product was analyzed by GC and its structure was characterized by FT-IR. The effects of molar ratio of butanol to oil (oleic acid or rapeseed oil), catalyst dosage, reaction temperature and reaction time on the conversion rates of oleic acid and rapeseed oil were investigated. The results showed that the optimal esterification conditions were obtained as follows: molar ratio of butanol to oleic acid 3∶1, catalyst dosage 0.8% (based on the mass of oleic acid), reaction temperature 110℃and reaction time 1.5 h. Under these conditions, the conversion rate of oleic acid and the yield of fatty acid butyl ester reached 88.6% and 83.5%, respectively. The optimal transesterification conditions were obtained as follows: molar ratio of butanol to rapeseed oil 10∶1, catalyst dosage 1.0% (based on the mass of rapeseed oil), reaction temperature 115℃ and reaction time 2.0 h. Under the optimal conditions, the conversion rate of rapeseed oil and the yield of fatty acid butyl ester achieved 85.6% and 80.1%, respectively. |
