Patent ID: 7632476

Claim:
A method of recovering carbon dioxide from synthesis gas stream generated within a facility having a synthesis gas reactor, a water-gas shift reactor and a steam generation system for generating steam for the synthesis gas reactor and for export, said method comprising: extracting a synthesis gas stream from the facility after the synthesis gas stream has passed through at least one process heat exchanger of the steam generation system wherein at least one process heat exchanger being located downstream of the water-gas shift reactor and the synthesis gas stream upon extraction from the facility having an initial steam content that is at or near dew point; exchanging heat from at least part of a steam stream to the synthesis gas stream, after extraction from the facility, to increase temperature of the synthesis gas stream while simultaneously adding steam to the synthesis gas stream such that a heated synthesis gas stream is produced that has a final steam content that is in a superheated state; introducing the heated synthesis gas stream to an absorption system having an absorption zone utilizing a solvent for absorbing the carbon dioxide contained within the heated synthesis gas stream, thereby to produce a rich liquid containing the carbon dioxide and a treated synthesis gas stream having a lower content of the carbon dioxide than said synthesis gas stream and a regeneration zone operatively associated with the absorption zone for receiving solvent after having absorbed carbon dioxide and disengaging the carbon dioxide from the solvent, thereby to regenerate the solvent and for returning the solvent after having been regenerated to the absorption zone; transferring heat from the heated synthesis gas stream to the regeneration zone for promoting the disengagement of the carbon dioxide from the rich liquid; recovering a carbon dioxide stream composed of the carbon dioxide separated from the rich liquid; and the flow rate of the steam stream being controlled so that between about 40 percent and about 90 percent of the carbon dioxide contained in the synthesis gas stream is recovered in the carbon dioxide stream.