Hydrothermal Conversion of Glycerin into Lactic Acid by a Continuous-Flow Reactor

Using a self-established laboratory scale continuous-flow reactor, the experimental research on continuous hydrothermal conversion of glycerin into lactic acid was made, to lay a foundation for quantity production of lactic acid from glycerin. The optimal operation condition for producing lactic acid in the continuous-flow reactor, and a ~60% lactic acid yield was achieved. Bad mixing of the reactants as well as a large surface area of the inner wall of the reactor tube decreased significantly the lactic acid yields, especially with a long residence time under a high concentration of alkali. The continuous-flow reactor was modified by substituting the 1/8’’ tube with a 1/4’’ tube and equipping a mixing device, and was tested to perform as well as the one with a 1/8’’ tube. The research results would help design and establish a more high-efficient continuous-flow reactor for hydrothermal conversion of glycerin into lactic acid.