Preliminary detoxification of dilute ammonia pretreated energycane enzymatic hydrolysate by activated charcoal for syrup production

This study investigated the detoxification of dilute ammonia pretreated energycane enzymatic hydrolysate using activated charcoal.  Energycane bagasse (non-commercial variety HO 02-113) was pretreated with ammonium hydroxide (28% v/v solution) and water at a ratio of 1:0.5:8 at 160 °C for 1h. Pretreated energycane bagasse was then hydrolyzed with commercially available enzymes. By-products such as formic acid, acetic acid, lactic acid, citric acid, furfural and HMF were formed during enzymatic hydrolysis. These compounds can inhibit processes such as fermentation and syrup production. Detoxification procedures were carried out to recover and/or remove the by-products and retain the sugars. Activated charcoal reduced the concentrations of formic acid, acetic acid, lactic acid, citric acid, furfural and HMF by more than 60%. These results strongly suggest that using activated charcoal can significantly reduce the amount of inhibitors without a noticeable loss of fermentable sugars.