PRODUCTION OF REDUCING SUGARS FROM SUGARCANE BAGASSE BY SUBCRITICAL STREAM HYDROLYSIS

Author (s) : Dr.V.K.Evanjalene & Dr. R. Subbaiya

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Abstract :
Lignocellulosic biomass remains promising renewable feedstocks for the production of biofuels due to its abundance and ecofriendly nature. Sugarcane bagasse containing holocellulose of 62.93 wt% (40.15 wt% cellulose and 22.78 wt% hemicellulose) and lignin of 20.81 wt% is a potential feedstock for bioenergy creation  and was used for the production of reducing sugars using subcritical water (SCW) treatment in a batch reactor system. The effect of process parameters such as temperature (140-220 °C) and reaction time (5-40 min) on the release of total reducing sugar (TRS) was investigated. The production of TRS was increased with temperature from 140-180°C and thereafter decreased. Maximum TRS of 274.29 mg/g was obtained at 180°C and 30 min. The formation of sugar inhibitors (5-HMF or Furfural) gradually increase with an increase in the temperature. Maximum total inhibitors (TI) produced was 50.86 mg/g at 220°C and 40 min hydrolysis time, which includes 46.29 mg/g of 5-HMF and 4.57 mg/g of furfural. The crystallinity index (CI) of the SCW treated bagasse sample obtained in X-ray diffraction analysis was found to be increased with reaction temperature indicating disruption of lignin structure and release of pentose sugars thereby exposing the crystalline structure of cellulose, but further increase in temperature decreased the CI abruptly due to the conversion of cellulose to glucose. The percentage of CI was 54.03% and 63.32% at 140 and 160°C. At 180°C the CI % decreased to 59.96% which further decreased to 34.77% at 220°C thereby altering the biomass to relatively amorphous.

Keywords : subcritical water, bagasse, hydrolysis, sugarcane bagasse, reducing sugars, Inhibitors, Crystallinity.

Conference Date : 30/08/2019

Pages : 264

Paper ID : 19255