<p>A process for the production of a fuel composition comprising hydrocarbons derived from carboxylic acids and/or carboxylic acid esters, which process comprises feeding hydrogen and a hydrocarbon-containing stream to a first reactor to reduce levels of olefins and/or heteroatom-containing compounds in the hydrocarbon-containing stream, and feeding the so-treated hydrocarbon-containing stream to a second reactor together with hydrogen and a carboxylic acid and/or ester to produce a second hydrocarbon-containing stream in which at least some of the hydrocarbons are derived from the carboxylic acid and/or ester.</p>
