COMBINED CO2 CAPTURE AND CONVERSION METHOD AND SYSTEM

摘要

Systems and methods are described that utilize mixed conductive membranes in conjunction with solid oxide electrolysis in a single unit operation. The mixed conductive membranes of the systems are high-flux electrochemical separation membranes that can selectively and efficiently capture CO2 from a source gas, e.g., a flue gas or fuel gas, by transporting the CO2 across the membrane in the form of carbonate ions followed by oxidation of the carbonate-ions at the second side of the membrane to reform CO2 in a capture stream. The solid oxide electrolysis can be immediately downstream of the capture system to convert the CO2 into CO and H2O into H2, for example thereby forming syngas thereby capturing CO2 and converting it to a more useful form.

主权项

1. A method for selective capture and conversion of carbon dioxide from a gaseous stream comprising:
contacting a feed stream with a mixed carbonate ion conducting membrane, the mixed carbonate ion conducting membrane having a first side and a second opposite side, the feed stream contacting the first side, the feed stream including carbon dioxide, the carbon dioxide being reduced to form carbonate ion upon contact between the feed stream and the first side, the carbonate ion migrating across the mixed carbonate ion conducting membrane to the second side; contacting the second side of the mixed carbonate ion conducting membrane with a capture gas stream, the carbonate ion being oxidized at the second side of the mixed carbonate ion conducting membrane to form carbon dioxide, the carbon dioxide being collected by the capture gas stream; immediately downstream of the second side of the mixed carbonate ion conducting membrane, contacting the capture gas stream with an electrode of a solid oxide electrolysis cell, the capture gas stream containing the carbon dioxide and steam, the carbon dioxide and steam of the capture gas stream being reduced at the electrode to form carbon monoxide and hydrogen and oxide ion, the oxide ion migrating across an electrolyte of the solid oxide electrolysis cell.