Patent EP-2105191-A1 (EP)
Inventor: ROST MIKE
IPC: C01B32/50
Filed: 2008-03-27
Abstract: The method comprises burning a fossil fuel in a combustion process (1) to produce carbon dioxide-containing exhaust gas (2), contacting the carbon dioxide-containing exhaust gas with an absorption medium in an absorption process (4) during a first process stage to absorb carbon dioxide by the absorption medium such that a partially loaded absorption medium and an exhaust gas are formed, which is partially free from carbon dioxide, and delivering the carbon dioxide from the loaded absorption medium (7) in a desorption process (5) during the first process stage. The method comprises burning a fossil fuel in a combustion process (1) to produce carbon dioxide-containing exhaust gas (2), contacting the carbon dioxide-containing exhaust gas with an absorption medium in an absorption process (4) during a first process stage to absorb carbon dioxide by the absorption medium such that a partially loaded absorption medium and an exhaust gas are formed, which is partially free from carbon dioxide, delivering the carbon dioxide from the loaded absorption medium (7) in a desorption process (5) during the first process stage to form a partially regenerated absorption medium, removing the partially regenerated absorption medium in the desorption process during the first process stage and recirculating in the absorption process. The partially regenerated absorption medium is combined with the partially loaded absorption medium to develop a mixed absorption medium. The carbon dioxide is absorbed by the mixed absorption medium to form a loaded absorption medium and a purified exhaust gas are formed, which is free from carbon dioxide to a large extent. The partially regenerated absorption medium is removed from a process stage of the desorption process, and the partially loaded absorption medium is removed from a process stage of the absorption process. The concentration of carbon dioxide of the mixed absorption medium is adjusted by a supply ratio between the partially regenerated absorption medium and the partially loaded absorption medium. The carbon dioxide is delivered from the loaded absorption medium in the desorption process to form a gas-vapor mixture from the gaseous carbon dioxide and vaporous absorption medium, and is delivered from the partially regenerated absorption medium in the desorption process in a second process stage to form a regenerated absorption medium and the gas-vapor mixture. The partially regenerated absorption medium is removed from the desorption process in several process stages with different concentrations of carbon dioxide and is recirculated in the absorption process. The concentration of carbon dioxide of the recirculated partially regenerated absorption medium is adjusted by the combination of partially regenerated absorption medium with different concentrations of carbon dioxide. The partially regenerated absorption medium is supplied to the absorption process in a stage, at which the concentration of carbon dioxide of the partially regenerated absorption medium is equal or less than the concentration of the partially loaded absorption medium. The carbon dioxide is thermally driven in the desorption process. The absorption medium is a liquid such as fluid, gas, aerosol or suspension. A vaporizable solvent is used as fluid and is a solution made of water and amine derivatives. The heat energy is supplied to the desorption process through vapor. The vapor is guided with the absorption medium into a heat exchanger in a heat exchanging process. The heat in a first preheating processes is removed from the partially regenerated absorption medium, and is delivered to the loaded absorption medium. The heat in a second preheating processes is removed from the regenerated absorption medium, and is delivered to the loaded absorption medium. The partially regenerated absorption medium is recirculated to the absorption process over a pumping process. The separated carbon dioxide is compressed in a compression process to develop a compressed or liquefied carbon dioxide, which is stored. An independent claim is included for a fossil fuel-powered power plant.