Carbon dioxide recovery from low concentration sources
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
InventorYudong Chen
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Abstract
A system and method of purifying gaseous carbon dioxide from a gaseous mixture obtained at low pressure from a flue gas by passing the gaseous mixture through a vacuum swing adsorption unit and then a gas purification unit to produce carbon dioxide having a purity of approximately 97% by volume or more.
Claims14
A method of purifying gaseous carbon dioxide from a gaseous mixture comprising 5% to 25% by volume carbon dioxide, said method comprising
- (a) obtaining a gaseous mixture from a flue gas at a low pressure of 1 to 5 atmospheres absolute;
- (b) flowing the gaseous mixture into an adsorbent bed of a vacuum swing adsorption unit having one or more adsorbent beds in which carbon dioxide is adsorbed;
- (c) using a vacuum pump to draw a carbon dioxide-rich stream from the adsorbent beds;
- (d) directing the carbon dioxide-rich stream through a compressor to produce a compressed carbon dioxide-rich stream;
- (e) flowing the compressed carbon dioxide-rich stream into a gas purification unit to produce a carbon dioxide product and a carbon dioxide-lean stream, the gas purification unit comprising at least one gas separation membrane;
- and
- (f) returning the carbon dioxide-lean stream to the vacuum swing adsorption unit.
A carbon dioxide purification system for recovering carbon dioxide from low pressure gaseous mixtures having low concentrations of carbon dioxide comprising:
- a gaseous mixture obtained from a flue gas, wherein the gaseous mixture contains approximately 5% by volume to approximately 25% by volume carbon dioxide at a pressure of approximately 1 to approximately 5 absolute atmospheres;
- a vacuum swing adsorption unit adapted to receive the gaseous mixture having one or more adsorbent beds in which carbon dioxide is preferentially adsorbed and a vacuum pump adapted to withdraw a carbon dioxide-rich stream from the adsorbent beds;
- a gas purification unit adapted to receive the carbon dioxide-rich stream from the vacuum pump and separate the carbon dioxide-rich stream into a carbon dioxide product and a carbon dioxide-lean stream from the carbon dioxide-rich stream, the gas purification unit comprising at least one gas separation membrane;
- and
- a conduit fluidly communicating between the gas purification unit and the vacuum swing adsorption unit being adapted to direct a portion of the carbon dioxide-lean stream to the vacuum swing adsorption unit.
Dependencies are inferred from the claim text.