Patent ID: 8338495

Claim:
A method of producing hydrocarbon oils from natural gas containing methane as a main component, comprising steps of: producing a synthesis gas containing hydrogen and carbon monoxide as main components by reacting the natural gas with at least one of steam and carbon dioxide in a tubular reformer filled with a reforming catalyst; producing Fischer-Tropsch oil by subjecting the produced synthesis gas to a Fischer-Tropsch reaction to form a reaction product, and separating a gaseous product from the reaction product; and upgrading the produced Fischer-Tropsch oil by subjecting it to hydrotreatment and distillation to produce the hydrocarbon oils, wherein the produced Fischer-Tropsch oil is allowed to pass through a coil in a convection section of the tubular reformer to recover excess heat generated in the synthesis gas producing step and use it as heat for at least one of hydrotreatment and distillation in the upgrading step.