The Design of Bioethanol Production Equipment as Renewable Energy from Coconut Water Waste through Fermentation and Distillation

Abstract

The limitations of fossil fuels and their environmental impact in the form of greenhouse gas emissions have encouraged the development of renewable energy sources. Bioethanol is a promising alternative because of its renewable nature, high octane value, and potential to reduce carbon emissions. Indonesia, as the world's largest coconut producer, generates abundant coconut water waste, which still contains fermentable sugar but is often discarded. This study aims to design and evaluate a laboratory-scale bioethanol production prototype that integrates a fermenter and distillation unit with waste coconut water as raw material. Fermentation was carried out using Saccharomyces cerevisiae with variations in yeast mass (50, 75, and 100 g/L) and fermentation time (3, 5, and 7 days). The ethanol concentration of the fermentation product ranged from 7 to 10%, while the distillation process increased the concentration to 24% under optimal conditions (100 g/L yeast, 7 days). The prototype, consisting of a stainless-steel fermenter, electric heating distiller, and Liebig condenser, demonstrated effective and integrated performance. The results of this study confirm the potential of coconut water waste as a bioethanol substrate and demonstrate the feasibility of a simple prototype for the development of a small-scale renewable energy system based on agro-industrial waste. However, further purification stages, such as fractional distillation or molecular dehydration, are still needed to meet bioethanol fuel standards.