Indo. J. Chem., 2012, 12 (3), 255 - 260 Budy Rahmat et al. 255 * Corresponding author. Tel/Fax : +62- 265 323531/325812 Email address : budy_unsil@yahoo.com EFFECT OF GLYCEROL SEPARATION ON PALM OIL TRANSESTERIFICATION Budy Rahmat 1,* , Imas Siti Setiasih 2 , and Roni Kastaman 2 1 Department of Agrotechnology, University of Siliwangi, Jl. Siliwangi No. 24 Tasikmalaya, West Java Indonesia 2 Department of Agroindustry, University of Padjadjaran, Jl. Dipatiukur No. 35 Bandung, West Java Indonesia Received June 27, 2012; Accepted November 29, 2012 ABSTRACT This research was aimed to study the effect of glycerol separation on palm oil transesterification. Objectives of this study were to suppress the use of excess methanol and shorten the processing time. This research consisted of: design-build reactor, the effect of the glycerol separation on the transesterification reaction, characterization of biodiesel, and mass balance analysis. The reactor was designed by integrating circulate stirrer pump, static mixer, and sprayer that will bring out the intense reaction in the outer tank reactor. The experiment in this research was the treatment of decreasing the quantity of methanol to 5:1 molar ratio and reducing of processing time to 20 min, which was arranged in a completely randomized factorial design. The result showed that, (i) the stirring system was effectively worked outside the reactor tank, and in its reactor tank occurred glycerol separation during the process; (ii) the rate of glycerol during the process followed the inverse regression equation of Ŷ = 66.44-351.17 X -1 ; (iii) the decrease in the level of methanol to 5:1 molar ratio and the reduction of processing time to 20 min in this engineering did not influence the biodiesel yield and quality that met the SNI 04-7182-2006 standard. Keywords: glycerol separation; biodiesel; palm oil; transesterification ABSTRAK Penelitian ini bermaksud untuk mengetahui pengaruh pemisahan gliserol pada transesterifikasi minyak sawit. Tujuan dari penelitian ini adalah untuk menekan penggunaan metanol berlebih dan mempersingkat waktu proses. Penelitian ini terdiri dari: rancang-bangun reaktor, efek pemisahan gliserol pada reaksi transesterifikasi, karakterisasi biodiesel, dan analisis neraca massa. Reaktor didesain dengan mengintegrasikan pompa pengaduk sirkulasi, mixer statis, dan sprayer yang akan membawa keluar reaksi intens dalam reaktor tangki luar. Percobaan dalam penelitian ini adalah perlakuan penurunan jumlah metanol sampai rasio molar 5:1 dan mengurangi waktu pengolahan untuk 20 menit, yang disusun dalam rancangan acak lengkap faktorial. Hasil penelitian menunjukkan bahwa, (i) sistem pengadukan itu bekerja efektif di luar tangki reaktor, sedangkan di dalam tangki reaktor terjadi pemisahan gliserol selama proses; (ii) tingkat gliserol selama proses mengikuti persamaan regresi invers Ŷ = 66,44-351,17 X -1 , (iii) penurunan tingkat metanol sampai 5:1 rasio molar dan pengurangan waktu proses sampai 20 menit dalam rekayasa ini tidak mempengaruhi hasil biodiesel dan kualitas yang memenuhi persyaratan SNI 04-7182-2006. Kata Kunci: pemisahan gliserol; biodiesel; minyak sawit; transesterifikasi INTRODUCTION Biodiesel could be synthesized from oil and methanol via transesterification reaction. Catalytic preparation of biodiesel has the problem on the production cost, which is particularly related on the properties of methanol and vegetable oil that are not miscible, thus the reaction need the strong and long stirring. Besides, the reaction is reversible and the yield is determined by the quantity of methanol as reactant [1]. Development on biodiesel production is aimed to give maximum conversion. The optimization of transesterification could be done by applying the open system [2-3] with two options of (1) employing the excess methanol and the cost will increase as the consequence and (2) immediately removing one of the products. Glycerol as the by product is usually separated after the reaction complete, event decantated at few hours before separation [4]. This action is conducted as the glycerol could be a reactant on the back reaction if the methanol is not employed in excess amount. In this research, the strategy to optimize the transesterification reaction was to gradually separate glycerol during the process. According to Law of Mass Action, removing of glycerol from the reaction system could compensate the excess methanol and increase the reaction rate. The aim of the research was to study