Studies on different pretreatments of sugarcane bagasse have been widely reported. such as physical- , ultrasonic- , steam explosion- , acid- , IL- , , and , alkaline- and urea- pretreatments. However, little was reported on the combination of dilute acid- and IL-pretreatments on lignocelluloses for their efficient conversion to sugars.
Prof. FANG Zhen and his team of Xishuangbanna Tropical Botanical Garden (XTBG) conducted a study with a purpose to get high glucose yield from sugarcane bagasse by enzymatic hydrolysis, while other C5 sugars are also recovered and utilized. Sugarcane bagasse was firstly pretreated by dilute sulfuric acid to remove hemicellulose as sugars by hydrolysis, and the fermentability of the hydrolysates was evaluated by the production of 2,3-butanediol with Klebsiella oxytoca. The remained cellulose in the solid residue was further pretreated by IL [AMIM]Cl to destroy its crystallinity for glucose by subsequent enzymatic saccharification.
In the study, dilute sulfuric acid-pretreatment could remove most of hemicellulose for fermentation and subsequent IL-pretreatment significantly decreased cellulose crystallinity. The pretreatments with both dilute acid and IL resulted in remarkably higher glucose yield (95.5%) as compared with the yields of 19.3% for untreated bagasse, 46.1% for only acid- and 40.8% for IL-pretreated samples in enzymatic saccharification.
The strategy seems a promising route to achieve high yield of sugars from both hemicellulose and cellulose for the fermentation to value-added products.
The study entitled “Combination of dilute acid and ionic liquid pretreatments of sugarcane bagasse for glucose by enzymatic hydrolysis” has been published online in Process Biochemistry.