摘要 |
Synthesis gas having a stoichiometric composition desirable for subsequent conversion into methanol or Fischer-Tropsch products from a substantially sulphur-free gaseous hydrocarbon feedstock is produced by the steps of: (I) feeding substantially sulphur-free hydrocarbon-containing gas 7, steam from boiler 18 and carbon dioxide 10 to a single primary reforming zone 8 comprised of an exchanger reactor containing a steam reforming catalyst under reforming conditions wherein hydrocarbon gas is partially reformed to produce a primary reformer effluent 11, (II) feeding substantially sulphur-free hydrocarbon-containing gas 13, oxygen-containing gas 15, steam from boiler 18, carbon dioxide 9 and primary reformer effluent 11 to a secondary reformer 12 containing reforming catalyst under reforming conditions wherein hydrocarbon gas is reformed to produce a secondary reformer effluent, (III) passing secondary reformer effluent 16 from step (II) to the primary reforming zone as indirect heating medium for the exchange reactor, (IV) removing the secondary reforming effluent 17 from the primary reforming zone. Preferably carbon dioxide is removed wholly or partially from the secondary reformer effluent and recycled in a further step, step (V), as feed to steps (I) and (II) of the process. <IMAGE> |