Pretreatment of Switchgrass for Production of Glucose via Sulfonic Acid-Impregnated Activated Carbon

Abstract

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.