Kinetics of Base Catalysed Trans-Esterification of Jatropha Oil using Potassium Hydroxide Extract from Ripe Plantain Peels.

摘要

Obtaining kinetic data such as the rate constant, reaction order and hence the rate law is key to a good design of reactors in which chemical reactions take place, predicting the mechanisms, rates and extent of these reactions. Temperature and concentration are the most critical of the reaction conditions for homogeneous reactions. Hence the kinetic study of the trans-esterification of jatropha oil in a batch reactor using ethanol in the presence of potassium hydroxide extracted from ripe plantain peels as the base catalyst was carried out. And from the study, it was discovered that as the temperature was raised from 75 to 83 oC, conversion of jatropha oil increased progressively within the time of 1 to 4 hrs. In 1 hr, the conversion value (0.352 mole) at 75 oC, doubled with just 8 oC rise in temperature (at 83 oC) to 0.752 mole. Conversion at 83 oC in 4 hrs recorded the highest value of 0.972 moles. The rate laws (−rA=1.083CA and−rA=CA) at 75 and 83 oC respectively agree with the pseudo first order assumption made that the trans-esterification of crude jatropha oil to its biodiesel was a first order reaction with respect to crude jatropha oil while keeping the ethyl alcohol in large excess