Gas to liquids (GTL) is a refinery process to convert natural gas or other gaseous hydrocarbons into longer-chain hydrocarbons, such as gasoline or diesel fuel. Methane-rich gases are converted into liquid synthetic fuels either via direct conversion using non-catalytic processes that convert methane to methanol in one step or via syngas as an intermediate, such as in the Fischer Tropsch, Mobil and syngas to gasoline plus processes. Using gas-to-liquids processes, refineries can convert some of their gaseous waste products (flare gas) into valuable fuel oils, which can be sold as is or blended only with diesel fuel.