Investigating the impact of ultrasound and combination of alkali/ultrasound as an effective pre-treatment on sugarcane bagasse for ethanol production

The aim of this work was to develop and optimize process parameters in ultrasound and sono-assisted alkali pretreatment process of sugarcane bagasse prior to hydrolysis and bioethanol fermentation processes. Following the optimization of ultrasound time and temperature, the influence of concentration of NaOH solution was examined. The optimal condition in ultrasound (35 kHz) pretreatment was achieved at 5 min and 65 oC. Ultrasound pretreatment of bagasse prior to hydrolysis step resulted in increased sugar concentration from 3.62 g/l (control, 25oC) to 5.78 g/l (65oC, 5 min). The maximum glucan conversion of 50.7% was achieved following sono-assisted alkali pretreatment (NaOH concentrations 3%). The micro-morphology and cellulose crystallinity for native and pretreated bagasse were investigated by Scanning electron microscopy (SEM) and X-ray diffraction, respectively. The maximum bioethanol production, in fermentation process using Saccharomyces cerevisiae, of 0.43 g/g glucose was achieved at sono-assisted alkali 3% pretreatment. The findings indicate that sono-assisted alkali pretreated bagasse can be used as a potential feed stock in bioethanol production.

کلیدواژه ها:

Sugarcane bagasse ، Sono- assisted alkali pretreatment ، Enzymatic hydrolysis ، Bioethanol ، Lignocellulose structure