PRARANCANGAN PABRIK ETANOL DARI GAPLEK DENGAN KAPASITAS 50.000 TON/TAHUN

Ethanol, which is also known as ethyl alcohol, is the most widely used alcohol in daily life. Ethanol is mostly used as a solvent for chemical. In the history for its usage, ethanol has long been used as fuel. Opportunities for development of ethanol in Indonesia is quite large, considering that ethanol usage as fuel for vehicles has increased lately. The ethanol from dried cassava plant is planned to operate 330 days/year and 24 hours/day with capacity 50,000 ton/year. The product obtained is ethanol with 99.5% purity. This plant will be built in Pacitan, East Java, because the place of the main raw material, which is dried cassava (gaplek), is located near there. Ethanol is made by hydrolyzing dried cassava with alpha amylase enzyme for two hours in the first reactor to form oligosaccharide. Oligosaccharide formed is then hydrolyzed further with gluco amylase enzyme to form glucose for 15 hours in the second reactor. Glucose obtained in this hydrolysis is fermented with Saccharomyces cerevicae for 24 hours to obtain ethanol. The fermentation product that contained a plenty of water and another substrate then purified using distillation process to obtain 65% purity then purified further using pervaporation membrane to obtain ethanol with 99.5% purity. The plant is built in 6.9 acres area and employs 355 employees. This plant requires 22,250 kg/hour dried cassava as the raw material. This plant demands 39,197.6572 kg/hour steam, 58,241.0867 kg/hour water, and 5,858.18 kVA electricity from generator. From calculation of economic evaluation results, fixed capital required is $35,680,127.76 + Rp 182,276,551,548.61 and working capital required is $9,847,935.26 + Rp 45,551,024,045.14. At 100% production rate, obtained ROI before tax of 33.09%, ROI after tax of 16.54%, POT before tax of 2.32 years, POT after tax of 3.77 years, with BEP at 41.58%, SDP at 19.01%, and 18.91% for DCFRR. Based on consideration of the economic evaluation results, this ethanol plant with capacity 50000 ton/year is worth to be studied further