<![CDATA[Non-alcoholic route biodiesel synthesis using suspended Candida rugosa lipaseBiodiesel synthesis using biocatalyst can improve the disadvantage of alkali catalyst. Biocatalysts are not homogeneously mixed, so its separation is easy and it is also able to direct the reaction specifically without any unwanted side reactions. However, the application of biocatalysts in alcoholic environment degrades the biocatalyst quickly, and its stability suffers. To solve this problem, this research proposes to perform biodiesel synthesis through a non-alcohol route so that the activity and stability of the biocatalyst can be preserved. The biocatalyst used was Candida rugosa lipase in suspended form. Methyl acetate which served as alkyl group source was reacted with triglycerides from palm oil. The reaction was performed in a batch reactor, and HPLC was used to analyze reactants and product concentrations. Research results indicated that more than 86% of fatty acid chains from the palm oil triglycerides were converted to biodiesel at a biocatalyst concentration of 4 %-wt of the substrate, oil:alkyl molar ratio of 1:12, and reaction period of 50 hours. Furthermore, the kinetic data obtained using suspended enzyme, were also shown by concentration profile of tri-, di-, monoglycerides and biodiesel versus time in 50 hours reaction time.Keywords: biodiesel synthesis, interesterification, Candida rugosa lipase, non-alcohol route, triglycerideAbstrakSintesis biodiesel menggunakan biokatalis mampu memperbaiki kelemahan katalis alkali, yaitu tidak bercampur homogen, sehingga pemisahannya mudah dan mampu mengarahkan reaksi secara spesifik tanpa adanya reaksi samping yang tidak diinginkan. Namun penggunaan biokatalis di lingkungan beralkohol menyebabkan biokatalis terdeaktivasi secara cepat dan stabilitasnya menjadi buruk. Untuk menyelesaikan masalah tersebut, dalam riset ini diusulkan melakukan sintesis biodiesel melalui rute non-alkohol agar aktivitas dan stabilitas biokatalis tetap tinggi. Biokatalis yang digunakan adalah Candida rugosa lipase dalam bentuk tersuspensi. Metil asetat sebagai pensuplai gugus alkil direaksikan dengan trigliserida dari minyak kelapa sawit. Reaksi dilakukan dalam reaktor batch dan HPLC digunakan untuk menganalisa reaktan dan produk. Hasil penelitian menunjukkan bahwa lebih dari 86% rantai asam lemak dari trigliserida minyak kelapa sawit berhasil di konversikan menjadi biodiesel pada kondisi konsentrasi biokatalis sebesar 4 %-wt substrat, rasio mol minyak:alkil sebesar 1:12 selama 50 jam reaksi. Selanjutnya, data kinetika menggunakan enzim tersuspensi juga ditunjukkan melalui profil konsentrasi tri-, di-, mono, dan biodiesel terhadap waktu selama 50 jam.Kata Kunci: sintesis biodiesel, interesterifikasi, Candida rugosa lipase, rute non-alkohol, trigliserida]]>
