Condensed Phase Catalytic Hydrogenation of Lactic Acid to Propylene Glycol




Propylene glycol is a nontoxic chemical used in polymers production, as a nontoxic antifreeze, and in food, drink, cosmetic, and pharmaceutical applications. Propylene glycol is currently made commercially by high pressure and high temperature hydrolysis of propylene oxide.


Description of Technology


Michigan State University’s invention provides a low-cost method of producing propylene glycol from lactic acid. The process produces high yields of propylene glycol from crude or unrefined lactic acid under reaction conditions with high selectivity and low byproduct formation. This invention represents an improvement in catalyst and conversion conditions that has potential to replace traditional petroleum-derived routes to propylene glycol with a lower cost, more environmentally friendly process.


Key Benefits

  • The reaction is carried out in aqueous phase with free lactic acid. There is no need to convert lactic acid to the alkyl lactate ester and essentially no organic solvents are required.
  • With ruthenium as the catalyst, the reaction can be carried out at much lower hydrogen pressures.


Patent Status


U.S. patent 6,403,884




Dennis Miller, Zhigang Zhang, james Jackson


Tech ID




Patent Information:


For Information, Contact:

Thomas Herlache
Assistant Director
Michigan State University