PetroSA's GTL refinery at Mossel Bay uses unique gas-to-liquids (GTL) technology, part of it under license from SASOL.
GTL is a refinery process that converts natural gas or other gaseous hydrocarbons into longer-chain hydrocarbons such as gasoline or diesel fuel. The process converts methane-rich gases into liquid synthetic fuels by direct conversion or, in PetroSA's case, by using synthetic gas (syngas) as an intermediate through the Fisher Tropsch process.
This series of conversions starts with the reforming of methane (natural gas) to carbon dioxide, carbon monoxide, hydrogen and water. The carbon monoxide to hydrogen (H2) ratio is adjusted using the water gas shift reaction and the removal of excess carbon dioxide in an aqueous solution of alkanolamine .
The synthesis gas (syngas) is then chemically reacted over an iron or cobalt catalyst to produce liquid hydrocarbons and other byproducts.
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