Patent ID: 7989509

Claim:
A process for producing higher molecular weight hydrocarbon compounds and/or oxygenates from a hydrocarbon gas comprising methane, said process comprising: generating an initial synthesis gas (“syngas”) stream comprising carbon monoxide and hydrogen in a two-stage process by reaction of hydrocarbon gas comprising methane, steam and oxygen; generating oxygen in an air separation plant having an air compressor driven by a gas turbine; combusting a fuel gas in exhaust from the gas turbine in a fired heater to provide at least a portion of a heat duty for preheating feed streams to synthesis gas production units; catalytically converting synthesis gas to at least one of hydrocarbons or oxygenates in a process unit, at least a portion of the initial syngas stream is provided as feed gas to the process unit; separating off-gas from the syngas conversion process, the off-gas including unreacted syngas from the syngas feed stream, inerts, reaction products, CO 2 and water vapour; generating additional synthesis gas in a catalytic steam/hydrocarbon reformer using the off-gas, a first part of the off-gas is used to provide at least a portion of the fuel gas for the reformer heating, and a second portion is used to provide at least a portion of the feed to the catalytic reformer mixed with steam; combining the additional syngas with the initial syngas to form a feed for the syngas catalytic conversion process; adding the combustion gas exiting the off-gas catalytic reformer furnace to the hot combustion gas used for process heating in the gas turbine exhaust fired heater; and adding the reformed synthesis gas stream leaving the off-gas catalytic reformer furnace to the initial syngas stream up-stream of a waste heat boiler producing high pressure steam for synthesis gas generation.