The invention relates to the technical field of
lactic acid preparation and particularly relates to a method for preparing
lactic acid through catalyzing
glycerol by a supported catalyst. According to the method, the selectivity of
lactic acid can reach 70-90%, and the conversion ratio of
glycerol can reach 72-100%. The method is characterized in that reaction is carried out
on glycerol which serves as a
raw material in a high-
pressure reactor under anaerobic and alkali source provided alkaline conditions in the presence of supported
copper oxide which serves as a catalyst, thereby obtaining lactic acid, wherein a support of the supported
copper oxide catalyst contains
metal oxides, including MgO, ZrO2, TiO2, CeO2 and ZnO,
activated charcoal or hydroxyapatite; the supported
copper oxide catalyst is easy to prepare, low in cost and relatively long in service life. The method has the advantages that the
reaction temperature and reaction pressure are low, the catalyst activity is high, the selectivity is good, the
reaction rate is high, and the process flow is safe and environmental-friendly and the like, so that the industrial prospect is good.