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Drying is a reduction of the moisture in a material to improve the quality of the material. In a sugar factory, bagasse is a by-product that is used as fuel in a boiler. This bagasse has a high moisture content, so it still needs to be dried. In this study, the drying was carried out by using a microwave where the bagasse was chopped about 3 cm and the sample for each experiment was 150 g. The power used is 50, 60, 70, 80, 90 and 100% of the maximum power of 900 W. The sample weight is measured every minute and drying is considered complete when the mass has not changed. This study was aimed to determine the kinetics of drying and effective diffusion, on the drying of bagasse by microwave. The results showed that the rational model is the most suitable mathematical model of drying kinetics with the general form MR = (a + bx) / (1 + cx + dx 2 ). This equation has the smallest R 2 value of 0.99926 and the largest RMSE value is 0.008874. The effective diffusion is in the range of 1.044 x 10 -7 to 2.009 x 10 -7 (m 2 /s). The activation energy value E a is 4.789 W/g. The smallest SMER is in the range of 0.3229 -0.4756 kg/kWh. SEC value is in the range of 3.10 to 2.10 kWh/kg. The geater the power used, the geater the D eff , SMER, MER, while the SEC will be smaller.

Ginger torch (Etlingera elatior Jack) is an herbaceous plant that is used as a flavoring, deodorizing, anti-oxidant, and antimicrobial. The fresh ginger torch has a high moisture content, so that it can't be stored for a long time because it will rot quickly. Drying is needed to preserve the ginger torch so that it can last longer. The research was aimed to determine the mathematical model, effective moisture diffusion, and activation energy for drying the leaves of Etlingera elatior Jack on a rotary dryer. The method used in this research was an experiment with three times repeated then followed by data analysis with curve expert 2.3.0 and MS-excel software. This research was performed by using a rotary dryer at temperatures of 60 o C, 70 o C, 80 o C, and 90 o C. The ginger torch was chopped about 1 cm, with a mass of 400 grams for each sample. Measurement of moisture content was carried out every 20 minutes. The results showed that the most suitable drying model was the Rational model with the general form of 𝑀𝑅 = (𝑎 + 𝑏𝑡)/(1 + 𝑏𝑡 + 𝑑𝑡 2 ). The effective diffusion was 8.528 -16.690 x 10 -8 m 2 /s, and the activation energy was 48.01 -50.67 kJ//mol.

Di dalam penggunaan berbagai sumber daya alam yang utama, pemakaian bahan bakar minyak bumi pada mesin diesel terus bertambah secara signifikan sehingga ketersediaan dari bahan bakar minyak tersebut yang bersifat non renewable dikhawatirkan. Pemanfaatan biodiesel dari minyak nabati saat ini sangat popular sebagaimana kebijakan pemerintah Indonesia saat ini telah diberlakukan untuk mengurangi kelangkaan bahan bakar minyak. Kulit pisang yang seringkali menjadi sampah rumah tangga dipertimbangkan dapat dijadikan minyak nabati sehingga minyak nabati tersebut dapat dicampur dengan minyak diesel untuk menghasilkan biodiesel. Di dalam penelitian ini, minyak nabati kulit pisang dicampur dengan minyak diesel dengan menggunakan kenaikan 5% minyak nabati tersebut. Biodiesel B10 dan B15 dari minyak nabati kulit pisang tersebut harus memenuhi spesifikasi Direktorat Jenderal Minyak dan Gas PERTAMINA untuk digunakan secara luas sebagai biodiesel alternatif untuk mesin diesel. Hasil uji kinerja dari mesin diesel menunjukkan bahwa biodiesel B15 dapat digunakan untuk mesin diesel