Persulfate based pretreatment to enhance the enzymatic digestibility of rice straw

Abstract

Oxidation induced by potassium persulfate was evaluated as an economic substitute for the Fenton-like reaction for the purpose of rice straw pretreatment in terms of temperature (80-140°C), potassium persulfate concentration (5-100mM) and process time (0.5-3h), an optimal pretreatment condition was identified: 120°C for 2 h with 75mM potassium persulfate concentration and yielded 91% enzymatic digestibility using 25.2FPU/g of biomass. Crystallinity index, SEM and SEM-EDS analyses revealed that biomass was indeed disrupted and components like silica were exposed. All this suggested that this persulfate-based pretreatment method, which is distinctively advantageous in terms of effectiveness and economics, can indeed be a competitive option.

Keywords: Enzymatic hydrolysis; Oxidative pretreatment; Rice straw; Structural features.