Processes and reactor systems are provided for the conversion of oxygenated hydrocarbons to paraffins useful as liquid fuels. The process involves the conversion of water soluble oxygenated hydrocarbons to oxygenates, such as alcohols, furans, ketones, aldehydes, carboxylic acids, diols, triols, and/or other polyols, followed by the subsequent conversion of the oxygenates to paraffins by dehydration and alkylation. The oxygenated hydrocarbons may originate from any source, but are preferably derived from biomass.