Materials and process for reversible adsorption of carbon dioxide

Abstract

A solid material is disclosed for reversibly adsorbing carbon dioxide. The material comprises a porous carrier material. Deposited on the carrier material is a salt that is capable of reacting with carbon dioxide. Optionally the solid material further contains a particulate, water-insoluble inorganic material.

The material can be used in a process for recovering carbon dioxide from a carbon dioxide containing gas mixture. The gas mixture can be atmospheric air. The process comprises a temperature swing between an adsorption temperature T₁ and a desorption temperature T₂. The difference between T₂ and T₁ is less than 200 ° C.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The invention relates generally to the reversible adsorption of carbon dioxide from a gas mixture, and more particularly to the reversible adsorption of carbon dioxide from ambient air.[0003]2. Description of the Related Art[0004]Carbon dioxide has been identified as a major contributor to climate change. Significant efforts are being made towards the development of adsorbent materials that adsorb carbon dioxide from gas mixtures, such as flue gases, that are relatively carbon dioxide rich. The focus is on adsorbent materials that irreversibly capture the carbon dioxide, for example calcium oxide. By sequestering the captured carbon dioxide in, for example, landfills or abandoned mines in the form of calcium carbonate, the amount of carbon dioxide in the atmosphere is effectively reduced.[0005]In principle capture of carbon dioxide in the form of calcium carbonate is a reversible process, in that carbon dioxide can be r...

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Benefits of technology

[0010]Another aspect of the invention comprises a process for recovering carbon dioxide from a carbon dioxide containing gas mixture comprising (a) at a first temperature T1, contacting the carbon dioxide containing gas mixture with a solid material capable of reversibly adsorbing carbon dioxide; and (b) desorbing at least part of the adsorbed carbon dioxide from the solid material at a temperature T2, such that T2>T1 and ΔT, defined, as T2 minus T1 is less than 200° C.

Problems solved by technology

However, the decomposition of calcium carbonate requires very high temperatures, in excess of 900° C. For the purpose of carbon dioxide sequestration its capture in calcium carbonate can be considered irreversible in that no captured carbon dioxide can be expected to be released during storage.

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