Bioethanol Production from Organic Fraction Makassar City Waste

Abstract

Petroleum reserves are increasingly depleted due to the increasing use of fuel oil, therefore it is necessary to find alternative energy. Waste problems are an important issue in urban environments in line with population growth and increased development activities, especially in Makassar City, so simultaneous waste management is needed. This study has 6 stages, namely: raw material preparation, raw material fractionation, holocellulose content analysis, acid hydrolysis, fermentation, and bioethanol yield analysis. The raw materials are divided into 3 fractions, namely fraction I waste which has starch content, fraction II waste which has more holocellulose content and fraction III waste which has more lignocellulose content. After dividing the waste fractions, the holocellulose content is then analyzed. The hydrolysis process using dilute sulfuric acid is carried out in two stages: the first stage at a temperature of 190oC and the second stage at 210oC. The next process is fermentation using Saccharomyces cerevisiae yeast for three days. The fermented liquid is analyzed for its alcohol content by density testing. The characterization results of Makassar City waste are fraction I (vegetables and fruits) contains the least holocellulose, which is 15.39% while fraction II (bamboo, grass, newspaper, paper, wood, and mango leaves) contains the most holocellulose, which is 71.8%. The results of hydrolysis carried out in two stages showed that fraction III had the highest sugar content, which was 8.84%. In 100 grams of fraction III sample that was hydrolyzed and fermented, 1330 ml of liquid containing 4.82% alcohol was produced.