Biodiesel Production Using Double-Promoted Catalyst CaO/KI/γ-Al2O3 in Batch Reactor with Refluxed Methanol

Abstract

A benign process for biodiesel production has been developed using heterogeneous gamma-alumina base as catalyst. This study was conducted using double-promoted catalyst CaO/KI/gamma-Al2O3 to improve the activity of catalyst and this research was the first one which employs that kind of catalyst for biodiesel production. The preparation of the catalyst was conducted by precipitation and impregnation methods. The effects of reaction temperature, reaction time, and the ratio of oil to methanol on the yield of biodiesel were studied. The reactions were carried out in a batch-type reactor system which consists of three-neck glass flask with 1000-ml capacity equipped with reflux condenser and hot plate stirrer. Results showed that CaO/KI/gamma-Al2O3 catalyst effectively increased the biodiesel yield about 1.5 times than that the single-promoted catalyst. The optimum condition for the production of biodiesel is as follows: the reaction temperature is 65 degrees C, the reaction time is 5 h, and the ratio of oil to methanol is 1:42. Under this optimum condition, the highest biodiesel yield of 95 % was obtained.