The Hydrolysis of Cow’s Rumen and Rice Straw Mixture using Sulfuric Acid and The Fermentation of Its Hydrolysate in Bioethanol Production

¹ Research Centre for Sustainable Production System and Life Cycle Assessment, National Research and Innovation Agency, Indonesia
² Chemical Engineering Department, Engineering Faculty, Universitas Negeri Semarang
³ Research Center for Behavioral and Circular Economics, National Research and Innovation Agency, Indonesia

^* Corresponding author: Megawati@mail.unnes.ac.id

Abstract

This study aims to investigate the effect of cow’s rumen and rice straw ratio on hydrolysis as well as sulfuric acid concentration, temperature, and time were also examined. The fermentation was also carried out, with the main focus on the effect of the yeast concentration. The more straw in the material, the higher the glucose. In the rumen and straw ratio of 40:60 and 80:20%, 0.3 M sulfuric acid, 90 oC, and 60 minutes, the glucose was 10.60 and 5.87 g/L. Hydrolysis at 90 was better than 80 oC. In the rumen and straw mixture of 40:60%, 0.6 M sulfuric acid, and 75 minutes, the glucose was 18.47 and 15.11 g/L. The catalyst concentration of 0.6 was also better than 0.3 M, in which the glucose could reach 17.32 and 8.46 g/L at a rumen and straw ratio of 0:100, 90 oC, and 45 minutes. Glucose in the hydrolysate could be fermented well. The higher the yeast concentration, the higher the ethanol content, respectively 1.22, 1.35, and 1.52% in 72 hours at yeast concentrations of 9, 15, and 20 g/L. Ethanol rose sharply within 24 hours and after 72 hours it continued to rise even though it started to slow down at 60 hours.