Method for combining desalination and osmotic power with carbon dioxide capture

Abstract

Carbon Dioxide capture processes utilizing ammonia, or ammonia in water as the capture fluid for carbon dioxide generate concentrated solutions of ammonium carbonate species in water, which are subsequently decomposed to capture the carbon dioxide and recycle the ammonia. Forward osmosis processes utilize ammonium carbonate species as draw solutions to pull water from saline solutions such as seawater in the ammonium carbonate solution. The ammonium carbonate solution is then heated to decompose the ammonium carbonate to ammonia and CO2 which are both reused, while a portion of the aqueous stream is recovered as pure water. Combination of carbon capture process with an integrated forward osmosis process provide great economies over standalone operations. Furthermore, the very high concentrations of ammonium carbonate provide a further opportunity to include osmotic power recovery cycles with the integrated forward osmosis and carbon capture process.