Keywords: barley straw, microwave irradiation, alkaline pretreatment, sugar concentration, total sugar yield, lignocellulose, microwave pretreatment
Microwave and microwave–alkali effect on barley straw for total sugar yield
Lignocellulose is the most remarkable plant material resource for obtaining energy; however, its utility is restrained by its recalcitrant structure. Therefore, it is necessary to apply a convenient pretreatment method to increase the sugar yield. Microwave pretreatment method assists to break down hard lignin structure for improved degradation of cellulose and releasing of sugar. The objectives of this study are to investigate microwave and microwave–alkali pretreatment efficiency of barley straw before enzymatic hydrolysis. In both pretreatment methods, remarkable findings were obtained as sugar concentration. The maximum reducing total sugar concentration of 354.1 mg/L was achieved after ten minutes of pretreatment time in 30 mL of 3% NaOH solution (w/v) at microwave power of 200 W. The evaluations of scanning electron microscopy (SEM) images were carried out within pretreatment of barley straw as well. The results suggest that microwave and microwave–alkali pretreatment can increase total sugar concentration.