CO2 CAPTURE VIA AMINE-CO2 PRODUCT PHASE SEPARATION

摘要

Systems and methods are provided for performing CO2 sorption and regeneration processes that can take advantage of phase changes between solutions of amine-CO2 reaction products and precipitate slurries, where the slurry particles can include solid precipitates formed based on the amine-CO2 reaction products. An amine solution can be used to capture CO2 from a gas phase stream. During this initial capture process, the amine-CO2 reaction product can remain in solution. The solution containing the amine-CO2 reaction product can then be exposed to a set of conditions which result in precipitation of a portion of the amine-CO2 reaction product to form a slurry. The precipitate slurry can be passed into one or more release stages where the conditions for the slurry are altered to allow for release of the CO2.

主权项

1. A method for separating carbon dioxide from a gas stream, comprising:
contacting a gas stream containing CO2 in a sorption zone with a sorption solution comprising an amine, the sorption solution having a total amine concentration of at least about 2.0 M, at a temperature of at least 10° C. to sorb at least a portion of the CO2 into the sorption solution and form a rich stream of the sorbed in the sorption solution comprising one or more amine-CO2 reaction products dissolved in the solution; passing the rich stream from the sorption zone to a second zone and precipitating at least a portion of the amine-CO2 reaction products to form a precipitate slurry; separating the precipitate slurry to form a portion enriched in precipitate solids and a first recycle stream, the first recycle stream comprising a majority of the solvent from the precipitate slurry; and passing the portion enriched in precipitate solids to one or more regeneration zones and desorbing the sorbed CO2 as gas to form a second recycle stream, the second recycle portion containing a lower concentration of CO2 than the rich stream and containing an increased concentration of amine relative to the rich stream, wherein the sorption solution comprises at least a portion of the first recycle stream and at least a portion of the second recycle stream.