Design of a selective solid acid catalyst for the optimization of glucose production from Oryza sativa straw

Abstract

A selective, green and fast method for the production of glucose from rice (Oryza sativa) straw is demonstrated. Aq. ammonia based pretreatment techniques played a crucial role in the removal of lignin and xylan from rice straw which in-turn accelerated glucan hydrolysis and improved the selectivity of glucose production. The cellulose isolated from rice straw is further hydrolyzed to glucose using a solid acid catalyst (activated carbon supported phosphotungstic acid, ∼40 wt% HPW/AC). Microwave irradiation of cellulose from rice straw for a short duration of 5 min at 100 °C yielded 11.2 wt% glucose relative to 8 wt% glucose produced from a hydrothermal hydrolysis process (3 h, 150 °C) with a substrate to catalyst wt/wt ratio of 1. Thus an effective biomass pretreatment (aq. ammonia–dil. H₂SO₄) method and an accelerated selective biomass hydrolysis process is developed.