Post-combustion CO2 capture with heat recovery and integration
AssigneeSaipem S.P.A.
InventorsSylvain Lefebvre, Ferrere Clerveaux
Life of this patent
Estimating the term…
Abstract
CO2 capture processes and systems can be improved by recovering thermal energy from particular streams for reuse in the stripping stage. Thermal energy can be recovered from the overhead gas stream of a stripper operated under vacuum pressure conditions, and thermal energy can also be recovered from a flue gas. A heat transfer circuit can be implemented for recovering thermal energy by indirect heat transfer from the overhead gas stream, a flue gas stream, and/or other streams to a heat transfer fluid. The heat transfer circuit can include multiple heat recovery loops arranged in parallel and the heated fluid can be supplied through a reboiler of the stripper to heat the solution in the reboiler.
Claims14
A CO2 capture process for capturing CO2 from flue gas generated by a host facility, the process comprising:
- in an absorption stage, directly contacting a flue gas stream with an absorption solution comprising water, potassium carbonate, and a biocatalyst that is free in solution and represented by a carbonic anhydrase to absorb CO2 and form a CO2-rich solution and a CO2 depleted gas;
- in a stripping stage, subjecting the CO2-rich solution to vacuum pressure conditions and temperature conditions below 100° C. to cause the release of CO2 from the CO2-rich solution to form a regenerated solution and an overhead gas stream comprising CO2 and steam;
- recycling the regenerated solution back into the absorption stage as at least part of the absorption solution;
- subjecting the overhead gas stream to heat recovery, comprising:
- compressing the overhead gas stream or a gas stream derived therefrom to increase a temperature thereof and produce a compressed gas stream;
- transferring heat from the compressed gas stream to a heat transfer fluid to form a heated fluid, the transferring comprising condensing water contained in the compressed gas stream;
- and
- transferring heat from the heated fluid to the stripping stage,
- wherein the transferring heat from the compressed gas stream to the heat transfer fluid and/or the transferring heat from the heated fluid to the stripping stage is performed by indirect heat exchange;
- removing the condensed water from the compressed gas stream;
- recycling the condensed water back into the regenerated solution to produce an aqueous regenerated solution;
- feeding a first portion of the aqueous regenerated solution back into the absorption solution for said recycling the regenerated solution;
- heating a second portion of the aqueous regenerated solution to generate a vaporized regeneration solution;
- and
- recycling the vaporized regeneration solution into the stripping stage.
Dependencies are inferred from the claim text.