INTEGRATION OF ACID-ENZYME HYDROLYSIS OF LIGNOCELLULOSIC BIOMASS TO FERMENTABLE SUGARS

摘要

Although many previous studies determined dilute acid pretreatment conditions that maximize xylose yields from pretreatment or glucose yields from subsequent enzymatic hydrolysis of the pretreated cellulose, this paper emphasizes the use of different conditions to realize the highest total fermentable sugar yields from both stages. The acid pretreatment tests were performed under the conditions of acid concentration at 0.05%, 0.25%, 0.50%, 1.0% and the temperature in the range of 160 to 180. The maximum yield for just xylose in acid pretreatment occurred at 170 with the acid concentration of 0.25%. However, the total fermentable sugar yields from the two stages occurred at the pretreatment conditions of temperature 180 and acid concentration 0.25%. The results show that the conditions for the highest xylose yield in pretreatment step did not give the highest glucose yield in enzymatic hydrolysis step nor total fermentable sugars yield from both stages. Therefore, the effects of dilute acid hydrolysis conditions on the following enzymatic hydrolysis yields were investigated.