Bioethanol production from coconut coir by using ammonia and enzymatic hydrolysis

Bioethanol is one source of energy that can be obtained from cellulose fermentation. Coconut coir as agricultural waste has high cellulose content that high potential as a bioethanol source. Coconut coir has 34.57 % of cellulose, 8.36 % of hemicellulose, and 34.97 % of lignin. This study purposed to convert coconut coir into bioethanol by using delignification, ammonia-enzyme hydrolysis, and fermentation. The delignification process used 5 % sulfuric acid, then involved ammonia and enzyme for hydrolysis process with various concentrations (1,3 and 5) % v/w and fermented with various time (5,7 and 9) days. From this study, using 5 % of sulfuric acid can be decreased 20.88 % of lignin content and the highest glucose content by using 5 % of enzyme 24.83 %. Enzyme hydrolysis has produced higher glucose content than ammonia hydrolysis, which was only 18.88% of glucose content, using a similar concentration,. It showed that enzymatic hydrolysis was more effective than ammonia hydrolysis. The fermentation process in this study used 1%(w/w) of Saccharomyces cerevisiae, pH 5 with room temperature (25-30 degrees Celsius), and NPK as nutrition. The samples were fermented with various fermentation times, and the highest bioethanol content was produced within five days of fermentation. In 5 days of fermentation, the sample treated by enzyme hydrolysis had 12.19 % higher than the sample treated by the ammonia hydrolysis process. The sample treated with ammonia hydrolysis only produced 11.53 % of bioethanol content and the sample treated with enzymatic hydrolysis produced 13.13 % of bioethanol content. In 5 days of fermentation, the yeast converted glucose into bioethanol effectively. Because after five days, the Saccharomyces cerevisiae growth rate and amount of nutrition supply have decreased.