Production of Bioethanol from Seed Media of Kelengkeng Fruits (Dimocarpus longan) using Acid Hydrolysis Method and Its Purification using Distillation Method

Daniel Alfarado (Chemistry Edcuation Laboratory, Faculty Teaching and Education, Sriwijaya University, South Sumatera, Indonesia)
Gierrald Abduch (Water Quality Laboratory, PERUMDAM Tirta Pinang, Rangkui Regency, Pangkalpinang, Bangka-Belitung, Indonesia)
Yesi Hikmahtika (SMAN 1 Bakam, Bangka Regency, Bangka-Belitung, Indonesia)
Annisa Nur Jannah (SMAN 25 Palembang, Kertapati Regency, Palembang, South Sumatera, Indonesia)

IJFAC (Indonesian Journal of Fundamental and Applied Chemistry)
Vol 11, No 2 (2026): June 2026

This research was conducted to determine the level of ethanol production from longan seed media waste with parameters of seed media weight and acid concentration. Bioethanol production is carried out by means of fermentation in media that has been added with inoculum Saccharomyces cerevisiae, yielding bioethanol that was then purified through simple methods. Quantitative analysis of ethanol content using a spectrophotometer with potassium dichromate reagent and all analyzes were repeated three times. The results of the study showed that the best variations in the concentration of hydrolyzed acid and seed weight of the media were found at a concentration of 4% (ethanol yield: 2.942%) and media seed weight of 5 grams (ethanol yield: 1.838%), respectively. The concentration of ethanol in the produced distillate is still relatively low, ranging from 1.75% to 2.89% (v/v), and its purity decreases as the total fermentation volume increases.Keywords: Dimocarpus longan, bioethanol, acid hydrolysis, saccharomyces cerevisae, destilation purification