TRANSESTERIFIKASI IN SITU BIJI JARAK: PENGARUH KADAR AIR DAN UKURAN PARTIKEL BAHAN TERHADAP RENDEMEN DAN KUALITAS BIODIESEL In Situ Transesterification of Jatropha Seeds: Effect of Moisture Content and Particle Size on Yield and Quality of Biodiesel

Abstract

The objective of this study was to investigate in situ transesterification process allowing to realize directly biodiesel production from jatropha seeds. The influence of moisture content (0.5, 2, 3 and 4 %) and particle size (10, 20 and 35 mesh) of jatropha seeds was examined to determine the best performance of the biodiesel production yield and its quality. Generally, the moisture content and particle size of jatropha seeds affected biodiesel production yield. An increase of biodiesel production yield was observed as moisture content and particle size of jatropha seeds were decreased. Highest biodiesel production yield (71 %) was obtained under seed moisture content of 0.5 % and particle size of 35 mesh. Effect of the moisture content and particle size of jatropha seeds on biodiesel quality was less important. In all experiments tested, the biodiesel quality was very good. The acid value was below 0.3 mg KOH/g of biodiesel, water and sediment content was very poor ( 210 mg KOH/g of biodiesel). In addition, quality of biodiesel produced under optimum process condition was in accord with Indonesian Biodiesel Standard. Keyword: Transesterification, in situ, jatropha seed, biodiesel ABSTRAK Kegiatan penelitian ini bertujuan untuk mempelajari proses produksi biodiesel secara langsung dari biji jarak melalui proses transesterifikasi in situ. Parameter kondisi proses yang dipelajari adalah pengaruh kadar air (0,5, 2, 3 dan 4 %) dan ukuran partikel bahan (10, 20 dan 35 mesh) terhadap rendemen biodiesel dan kualitasnya. Kadar air dan ukuran partikel bahan berpengaruh nyata terhadap rendemen biodiesel. Semakin kecil kadar air dan ukuran partikel bahan, rendemen biodiesel dan efektifitas proses transesterifikasi in situ biji jarak semakin meningkat. Rendemen biodiesel tertinggi (71 %) dihasilkan dari perlakuan kadar air dan ukuran partikel bahan 0,5 % dan 35 mesh. Biodiesel yang dihasilkan dari proses transesterifikasi in situ biji jarak mempunyai bilangan asam, viskositas, air dan sedimen yang relatif rendah, yaitu 0,27 mg KOH/g biodiesel, 210 mg KOH/g biodiesel. Ukuran partikel bahan tidak berpengaruh nyata terhadap bilangan penyabunan dan ester biodiesel, sedangkan kadar air bahan menunjukkan pengaruh yang nyata. Kata kunci: Transesterifikasi, in situ, biji jarak, biodiesel