High-pressure pretreatment of rice straw for optimizing the fermentable sugar yield

Rice straw has proved to be a prospective source of renewable energy owing to high polysaccharic content and abundant availability. On hydrolyzing rice straw, fermentable sugars could be produced. In this research, organosolv was used to pretreat rice straw in high-pressure autoclave reactor under multiple conditions for removal of lignin and release of trapped polysaccharides. Rice straw composition was evaluated in accordance with the rules of the National Renewable Energy Laboratory.
The temperature ranged from 130, 140 and 150 degrees Centigrade and time varied as 20, 30 and 40 minutes. Temperature and time have significantly impacted the quantity of sugar and lignin. Sugar yield at 140 degrees Centigrade and 30 minutes was discovered to be maximum. In this condition of pretreatment, it was observed that nearly all hemicellulose was solubilized, about 75% of lignin was removed and over 80% of cellulose was released. Removal of lignin promotes the release of cellulose from the matrix of biomass. Overall, this research demonstrated the potential for a high-pressure reactor to effectively remove lignin, enhancing fermentable sugar output
Reference:
National Renewable Energy Laboratory (NREL), Chemical analysis and testing laboratory analytical procedures. NREL, Golden, CO, USA