PEMBUATAN BIODIESEL DARI MINYAK JELANTAH MELALUI PROSES ESTERIFIKASI DENGAN BANTUAN KATALIS ALUMINA TERSULFONASI UNTUK PENURUNAN KADAR ASAM LEMAK BEBAS

Abstract

ABSTRACT

Esterification of Free Fatty Acid (FFA) in cooking oil has been done in a biodiesel production by sulfonated alumina catalyst. Esterification carried out with the addition of sulfonated alumina catalyst variation of 1%, 3%, and 5%   (w/v), the volume ratio of methanol/oil was 0,9; 1,2; and 1,5 (v/v) at 60⁰C with variation of time 1, 3, and 5 hours. Free Fatty Acid (FFA) result was analyzed using NaOH titration. As the comparison of t,he solid catalyst cultivation performence was also carried out by esterification of homogeneous sulfuric acid liquid catalyst. The esterification of cooking oil continued to transesterification stage which has the lowest FFA at 60⁰C for 1 hour with the addition of 1% NaOH, and the volume ration of methanol/oil was 1,5 (v/v). The optimum condition of cooking oil esterification with initial FFA content was 7,20 riched at the volume ratio of  methanol/oil 1,5 (v/v), catalyst concentration 1% (w/v) for 1 hour of reaction. FFA conversion at the optimum condition was 90% with the final content of FFA was 0,72. By the same of optimum condition as using the cultivation of solid catalyst, the FFA content carried out from esterification using homogeneous sulfuric acid liquid catalyst was 90,42% with the final content of FFA was 0,69. The outcome of biodiesel from transesterification was in the form of a clear yellow liquid and the yield was 85%.

Key word: sulfonated alumina, cooking oil FFA, esterification, transesterification, biodiesel.