STM Article Repository

A comparative study was conducted to estimate biodiesel productivity of five varieties of castor beans: Ricinus communis zanzibariensis {white black} (castor 1), Ricinus communis sanguineus (castor 2), Ricinus communis carmencita (castor 3), Ricinus communis zanzibariensis {dark black} (castor 4) and Ricinus communis {black Tanzania}(castor 5). The castor beans were preheated to a temperature between 22 and 33 ° C and then pressed with a manual hydraulic press, under 170 bars. The oil obtained was subjected to the transesterification reaction with methanol (99.98% pure) in a proportion of 5: 1 in the presence of sodium hydroxide as a catalyst (10,672g) for 02 hours at temperature between 60 and 70 °C. Purification was performed by reacting the methyl ester formed with heated water (55 °C) and acetic acid. The density, the kinematic viscosity at 21 ° C and the proportion of residual soap were determined later. The results for five castor varieties showed that the oil yields varied from 24 to 26.96 %; the volume of methyl ester was higher with castor 4 and lower with castor 5 but there was no significant difference in the biodiesel yields. Castor 2 has the best yield of biodiesel (93.5%), followed by castor 5 (92.5%), castor 3 (91%), castor 1 (90.75 %) and castor 4 (90%). Therefore castor oil 2 has a better potential for biodiesel production.