NOVELTY - A catalytic process for hydrogenating glycerol for the production of lower alcohols by glycerol conversion which is a one-step catalytic process, which is independent or does not require the external addition of hydrogen gas, involves: subjecting a water, methanol and glycerol reaction mixture to heating under inert nitrogen system pressure over a metal heterogeneous catalyst and setting the reaction mixture in amounts to induce or to control catalytic hydrogenation.    USE - For hydrogenating glycerol for the production of lower alcohols (selected from 1,2-propanediol, 1-propanol or 2-propanol) by glycerol conversion which is a one-step catalytic process (all claimed); for converting the byproduct stream of biodiesel production into valuable chemical products.    ADVANTAGE - The method provides a glycerol conversion of greater than or equal to 85%, with a combined selectivity of lower alcohols of greater than or equal to 45%, particularly of which at least 39% is 1,2-propanediol and with yield of 34.8 in the former case of 45%. The method produces 1,2-propanediol in a greater than or equal to 30% yield. The method is one-step catalytic method, and uses metal heterogeneous catalyst without external addition of hydrogen gas under inert nitrogen system pressure. The method effectively uses the crude glycerol stream avoiding separation steps after transesterification. The method runs the hydrogenation reaction of glycerol under inert system pressure excluding the external addition of hydrogen gas. The reaction in liquid phase eliminates the need of heat of vaporization of oxygenate feedstocks. The one step method does not require external hydrogen addition to hydrogenate glycerol, takes advantage of the methanol contamination and water, which are already components of the crude glycerol stream after transesterification, to produce the needed hydrogen, where the needed hydrogen mainly forms from methanol and water and limits the sacrifice of glycerol substrate, requires no use of homogeneous additives, uses the same conditions, catalyst and reactor, proceeds in liquid phase and in milder conditions; and uses crude glycerol stream avoiding separation steps. The method minimizes undesirable decomposition reactions and carbon monoxide formation.