LAPORAN HIBAH PENELITIAN STRATEGIS NASIONAL TAHUN ANGGARAN 2010
PENGEMBANGAN TEKNOLOGI BARU PRODUKSI BIOETANOL DARI NIRA SIWALAN (Borassus flabellifer) MENGGUNAKAN FLOCCULENT Saccharomyces cerevisiae
Agustin Krisna Wardani, STP, MSi, PhD Ir. Aji Sutrisno , MSi, PhD Dr. Ir. Bambang Susilo, M.Agr.
Dibiayai Oleh Direktorat Jenderal Pendidikan Tinggi, Kementerian Pendidikan Nasional sesuai dengan Surat Perjanjian Penugasan Dalam Rangka Pelaksanaan Hibah Penelitian Strategis Nasional Tahun Anggaran 2010 Nomor : 522/SP2H/PP/DP2M/VII/2010, tanggal 24 Juli 2010
UNIVERSITAS BRAWIJAYA NOVEMBER 2010
RINGKASAN
Untuk mencapai proses produksi etanol yang ekonomis pada proses hulu (upstream processing) maka bahan baku nira siwalan digunakan sebagai medium fermentasi. Selanjutnya penggunaan strain flocculent S. cerevisiae sebagai penghasil etanol ditujukan guna mereduksi biaya produksi pada proses hilir (downstream processing) karena strain ini memiliki kemampuan berflokulasi setelah proses fermentasi. Sehingga tahap pemisahan etanol dari media fermentasi yang membutuhkan biaya tinggi tidak diperlukan lagi. Optimasi fermentasi pada penelitian ini dilakukan untuk meningkatkan produktifitas produksi etanol, yaitu dengan penambahan berbagai konsentrasi inokulum dan konsentrasi urea sebagai sumber N. Selanjutnya Response surface methodology (RSM) dengan Central Composite Design (CCD) digunakan untuk mempelajari pengaruh kombinasi komponen (konsentrasi inokulum dan urea) terhadap produktifitas etanol. Hasil kajian menggunakan metode RSM (Response Surface Methodology) menunjukkan bahwa kondisi optimum dalam menghasilkan etanol tertinggi dicapai pada kondisi konsentrasi inokulum sebesar 16,41% dan konsentrasi urea sebagai sumber nitrogen sebesar 0.31%. Kadar etanol yang dihasilkan dari titik optimum ini adalah sebesar 7,826%. Hasil verifikasi prediksi model menunjukkan konsentrasi etanol sebesar 7,705%. Sedangkan yield etanol yang dihasilkan pada proses optimasi ini adalah sebesar 0,42 dengan efisiensi sebesar 82%
SUMMARY
Response surface methodology (RSM) was employed to study the effects of two parameters (inoculum concentration and urea concentration) on the production of ethanol from siwalan juice in flask cultures by flocculating Saccharomyces cerevisiae strain. An experiment was designed by setting two parameters at three levels: X1 = inoculum concentration (10, 15, 20%); X2 = urea concentration (0.2, 0.3, 0.4%). A central composite design (CCD) was chosen to explain the combined effects of two parameters and to design the minimum number of experiments. The statistical analysis of the results showed, in the range studied, the inoculum and urea concentration had an effects on the ethanol production. The model predicted that maximum ethanol production was achieved at inoculum concentration of 16,41% and 0,31% of urea. Maximum ethanol production of 7,826% was achieved under the optimized condition. This values was in good agreement with experimental values, thus confirming the reliability of our empirical model in optimizing ethanol production by flocculating Saccharomyces cerevisiae. Yield and efficiency of ethanol production was 0,42 and 82%, respectively.
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