Pre-Hydrolysis of Sugarcane Straw (Saccharum officinarum L.) Using Oxalic Acid and Aspergillus niger Crude Extract

• Main Author: Dwi Sulistyo, Yonatan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/42757
• Institution: Institut Teknologi Bandung

Sugarcane straw as one of lgnocelluloce biomass resources has not been utilized optimally in Indonesia. This biomass is frequently left in the field and burnt after the harvest period. Lignocellulose is potentially utilized as a substrate to produce other products, such as xylitol. The main substrate to produce xylitol is hemicellulose, which is bound in the lignocellulose together with lignin and cellulose. A pretreatment like pre-hydrolysis should be conducted to remove and dissolve hemicellulose into a solution. It has been discovered that dilute acid is a good agent for high temperature pre-hydrolysis in industries, while dilute organic acid could produce toxic compounds (furfural and hydroxymethyl furfural (HMF)) only a few or nearly undetected. Therefore, this research aims to investigate the effect of oxalic acid and Aspergillus niger crude medium extract for the pre-hydrolysis of sugarcane straw. Various temperatures (130, 160, and 190 oC) are used to evaluate the best treatment compared to control (H2SO4, 3% (w/w), 130 oC). The results revealed that Aspergillus niger could produce oxalic acid with the highest concentration 1,84 g/100 mL. The crude medium extract after cultivation could increase the accessibility of lignocellulose as the effect of hemicellulose and lignin hydrolysis. The best result of hemicellulose hydrolysis was observed at 190 oC with the final hemicellulose mass 1,27 ± 0,0225 g. This result was lower compared to oxalic acid pre-hydrolysis at 160 oC (1,39 ± 0,0582 g), but remain higher than control (0,31 ± 0,0648 g). The hydrolyzate from crude medium extract pre-hydrolysis had lower toxicity compared to others because no toxic compunds (furfural and HMF) were detected. This result shows that the hydrolizate is relatively safe to be used in further fermentation process.