Hydroxyl Radical-Aided Thermal Pretreatment of Algal Biomass for Enhanced Biodegradability

A team led by Le Gao of the Chinese Academy of Sciences investigated a novel hydroxyl radical-aided approach for pretreating algal biomass. In this process, hydroxyl radicals were used in combination with heating to alter the crystalline structure and hydrogen bonds of cellulose in the algal biomass. FeSO₄ and H₂O₂ were also used to initiate the formation of hydroxyl radicals. This method released trapped polysaccharides in algal cell walls and converts them into fermentable sugars. The optimal pretreatment conditions were also identified using a central composite design.

The method increased the amount of glucose released from the algal biomass, enhancing algal biomass digestibility. The new pretreatment requires low concentration of chemical solvents and milder temperature conditions, which can prevent the toxic and corrosive effects. This could be useful for biochemical conversion of algal biomass to fuels and chemicals.