FIELD: carbon capture.
SUBSTANCE: invention relates to improved CO2 capture methods and systems, as well as heat integration systems and methods for heat recovery and reuse in a CO2 capture operation. The method for capturing CO2 from flue gas produced by a receiving facility includes an absorption step by directly contacting the flue gas stream with an absorption solution containing water and a carbamate-free absorbent to produce a solution rich in carbon dioxide and depleted in CO2 gas. At the stripping stage, exposure of the enriched solution to reduced pressure and temperature conditions below 100°C causes the release of carbon dioxide and the formation of a regenerated solution and an overhead gas stream containing CO2 and steam. The regenerated solution is recycled back to the absorption stage in the form of at least a portion of the absorption solution. The effect of heat recovery on an overhead gas stream includes compressing an overhead gas stream or a gas stream derived from it with an increase in its temperature and obtaining a compressed gas stream, transferring heat from the compressed gas stream to a heat transfer fluid to form a heated fluid, and transferring heat from the heated fluid to stripping stage.
EFFECT: use of low-grade waste heat streams, having a lower energy quality than steam, in order to meet the need for thermal energy for the operation of the reboiler and a significant reduction in energy consumption of the CO2 capture plant at the receiving enterprise.
58 cl, 10 dwg, 3 tbl, 5 ex
