Pretreatment of sugarcane bagasse by ultrasound energy and dilute acid

In order to improve the efficiency of conversion of lignocellulosic materials to simple sugars in an environmentally friendly manner, the efficiency of ultrasonic pretreatment, as an alternative pretreatment method to conventional ones, was studied. Ultrasound waves with their mechanical features on degradation of organic network and effect on the chemical reactions can be used as the new method for pretreatment of lignocellulosic material. The influences of enzyme, particle size, acid concentration, power of ultrasound, and time of irradiation of ultrasound on releasing the simple sugars were investigated. The optimal conditions of pretreatment were obtained by using Taguchi method. The results indicate that the sequence of influential factors is enzyme, particle size, acid concentration, duration of ultrasonication, and power of ultrasound. Under optimal conditions (using enzyme, particle size < 0.18 mm, acid concentration (v/v) 3%, ultrasound power 120 W and 180 s ultrasound time) the sugars' yield was 26.01 (g/L) which was 94.49% of the expected theoretical result. This suggests that ultrasound‐acid pretreatment of sugar cane bagasse can be used as an effective method for pretreatment though at this stage much more information is required.