Catalytic synthesis of 5-hydroxymethyl furfural from sorghum syrup derived fructose

Abstract

5-Hydroxymethyl furfural (HMF) is regarded as a very important platform chemical with versatile application. Sucrose derived from sorghum syrup was successfully explored for the synthesis of HMF. The current study employed a chemo-catalytic approach for the conversion of hexose component of sorghum syrup to HMF. The main objective of this study was to catalytically hydrolyse the sucrose in the sorghum syrup to glucose and fructose and subsequently dehydrate the hexoses to yield HMF. Seralite SRC120 (cationic resin) was used as a heterogeneous solid acid catalyst and the reaction was conducted in water. A statistical Box-Behnken design was employed for the optimization of the reaction parameters. RSM experiments indicated a maximum of 65 % HMF yield using 0.5 % (v/v) syrup loading and 1.25 % (w/v) catalyst loading with reaction time of 1 h. Glucose remained unconsumed during the reaction. The unreacted glucose (from hydrolysed sucrose) was used as a major carbon source for microbial cell enrichment that can possibly lead to the complete utilization of carbohydrates from the sorghum plant.