The present work studies the influence of the temperature (200-240 degrees C), pressure (38-50 bar), glycerol concentration (10-50 wt.%) and mass of catalyst/ glycerol mass flow rate ratio (W/m(glycerol) = 10-40 gcatalyst min/g glycerol) during the aqueous phase reforming (APR) of a glycerol solution obtained from the production of biodiesel. The operating conditions exerted a statistically significant influence on the reforming results. Specifically, the global glycerol conversion and the carbon converted into gas and liquid products varied as follows: 4-100%, 1-80% and 16-93%, respectively. The gas phase was made up of H2 (8-55 vol.%), CO2 (34-66 vol.%), CO (0-4 vol.%) and CH4 (6-45 vol.%). The liquid phase consisted of a mixture of alcohols (monohydric: methanol and ethanol; and polyhydric: 1,2-propanediol, 1,2-ethanediol, 2,3-butanediol), aldehydes (acetaldehyde), ketones (C3-ketones: acetone and 2-propanone1-hydroxy; C4-ketones: 2-butanone-3-hydroxy and 2-butanone-1-hydroxy; and cyclic ketones), carboxylic acids (acetic and propionic acids) and esters (1,2,3-propanetriol-monoacetate), together with unreacted glycerol and water. The relative amount (free of water and un-reacted glycerol) of these compounds in the liquid phase was as follows: monohydric alcohols: 4-47%, polyhydric-alcohols: 14-68%, aldehydes: 0-5%, C3-ketones: 2-33%, C4-ketones: 0-10%, ciclo-ketones: 0-6%, carboxylic acids: 2-43%, and esters: 0-46%. This process turned out to be highly customisable for the valorisation of crude glycerol for the production of either gaseous or liquid products. Gas production is favoured at a low pressure (39 bar), high temperature (238 degrees C), high W/m(glycerol) ratio (38 g catalyst min/g glycerol) and employing a 15 wt.% glycerol solution. A high pressure (45 bar), medium temperature (216 degrees C), medium W/m(glycerol) ratio (22 g catalyst min/g glycerol) and the feeding of a 16 wt.% glycerol solution favours the production of liquid products. (C) 2015 Elsevier Ltd. All rights reserved.