Efektivitas Variasi Konsentrasi HCl Pada Proses Hidrolisis Onggok Singkong Dalam Pembuatan Bioetanol Generasi Kedua

Abstract

Declining fossil energy reserves and increasing greenhouse gas emissions are driving the development of second-generation bioethanol based on lignocellulosic biomass. Cassava onggok, solid waste from the tapioca industry, has the potential to be utilized as a fermentation substrate due to its high starch and cellulose content. This study aims to assess the effect of variations in hydrochloric acid (HCl) concentration on acid hydrolysis efficiency, soluble sugar content, bioethanol content, and bioethanol yield from cassava onggok. The research process includes pretreatment, hydrolysis with HCl at concentrations of 0.1 N, 0.2 N, and 0.3 N, fermentation using Saccharomyces cerevisiae yeast, and determination of distilled bioethanol content based on the conversion of bioethanol density produced (referring to the table Densities of Aqueous Organic Solution: Ethy Alcohol). The results showed that the increase in HCl concentration was directly proportional to the increase in sugar content (%Brix), bioethanol content, and yield. HCl concentration of 0.3 N produced the highest values: soluble sugar 8.0 %Brix, bioethanol 11.5%, and yield 22.12%. This research confirms the importance of optimizing the hydrolysis stage to increase the conversion efficiency of lignocellulose into bioethanol. The utilization of cassava onggok not only supports the transition to renewable energy, but also helps reduce agro-industrial waste in cassava growing areas such as Lampung Province.