Promoted Production of Lactic Acid from Glucose by Calcium Hydroxide in the Presence of Hydrogen

Graphical Ca(OH) 2 shows an excellent activity for the production of lactic acid from glucose in the presence of H 2 . Under the condition, H 2 can also inhibit the decomposition of lactic acid. Strong alkalinity of the catalyst facilitates the occurrences of the intermediates such as dihydroxyacetone or glyceraldehydes, and then improves glucose conversion to lactic acid. Catalytic conversion of glucose to lactic acid is a green promising strategy for the effective utilization of biomass-derived carbohydrates to generate valuable chemicals. The generation of lactic acid would also be distinguishing in different reaction atmospheres. In this work, we firstly investigated the decomposition of lactic acid and glucose transformation to lactic acid in H 2 . No obvious decomposition of lactic acid was observed in H 2 . The activity testing results showed that glucose could be completely converted over the selected hydroxides, while the formation of lactic acid was closely related to the alkalinity of hydroxide. The yield of lactic acid was remarkably obtained to be 87 % over Ca(OH) 2 at 220 °C for 3 h. Stronger alkalinity of the catalyst would facilitate glucose isomerization to fructose, and then easily be transformed into dihydroxyacetone or glyceraldehyde intermediates through reverse aldol condensation, which is beneficial to the generation of lactic acid.