Disclosed is a process for hydrogenating 3-hydroxypropionic acid, or
esters thereof, or mixtures of the acid and the ester, in a liquid phase,
in the presence of a ruthenium catalyst, alone, or in combination with at
least one or more additional metal catalyst wherein the metal is
molybdenum, tungsten, titanium, zirconium, niobium, vanadium, chromium,
or mixtures of the metals.