Gas separation process
First Claim
1. A process for restoring the ability of an alkaline earth metal oxide to react with CO2, wherein the alkaline earth metal oxide is used in a cyclic process, wherein the alkaline earth metal oxide is reacted with CO2 to form an alkaline earth metal carbonate and the alkaline earth metal carbonate is calcined to regenerate the alkaline earth metal oxide, the process comprising the steps of:
- (a) contacting the alkaline earth metal oxide with water to form an alkaline earth metal hydroxide;
(b) heating the alkaline earth metal hydroxide in a first gas stream, wherein the first gas stream comprises CO2, to a temperature higher than the normal decomposition temperature for the alkaline earth metal hydroxide; and
(c) dehydrating the alkaline earth metal hydroxide to regenerate the alkaline earth metal oxide.
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Accused Products
Abstract
A process for the separation of carbon dioxide from gas mixtures is disclosed in which a metal oxide sorbent, which is used to capture and release carbon dioxide, is recycled. The process incorporates the regeneration of the carbon dioxide capture capacity of the metal oxide to maintain a high capture capacity over many cycles. The regeneration involves hydrating the metal oxide and then heating the resulting metal hydroxide under a gas atmosphere that is effective to suppress the dehydration of the hydroxide so that dehydration occurs at an elevated temperature. The regeneration may also be used independently from the carbon dioxide separation process to produce, from a metal hydroxide, a metal oxide having an enhanced resistance to attrition and fragmentation.
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Citations
19 Claims
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1. A process for restoring the ability of an alkaline earth metal oxide to react with CO2, wherein the alkaline earth metal oxide is used in a cyclic process, wherein the alkaline earth metal oxide is reacted with CO2 to form an alkaline earth metal carbonate and the alkaline earth metal carbonate is calcined to regenerate the alkaline earth metal oxide, the process comprising the steps of:
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(a) contacting the alkaline earth metal oxide with water to form an alkaline earth metal hydroxide; (b) heating the alkaline earth metal hydroxide in a first gas stream, wherein the first gas stream comprises CO2, to a temperature higher than the normal decomposition temperature for the alkaline earth metal hydroxide; and (c) dehydrating the alkaline earth metal hydroxide to regenerate the alkaline earth metal oxide. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification