Method and device for producing calcium

摘要

The method comprises exposing limestone or other carbonates at high temperature, produced through combustion of fuel with oxidation agent and then calcinating to a product, which is subsequently cooled through contact with a cooling medium. The carbonate is supplied to a first oven area (2) containing a calcination zone (6). The fuel and a gas are burned with oxygen content of 90 vol.% and the carbon dioxide-rich exhaust gas emerging during the combustion and calcination is partially recirculated as recycled gas in the oven area. The method comprises exposing limestone or other carbonates at high temperature, produced through combustion of fuel with oxidation agent and then calcinating to a product, which is subsequently cooled through contact with a cooling medium. The carbonate is supplied to a first oven area (2) containing a calcination zone (6). The fuel and a gas are burned with oxygen content of 90 vol.% and the carbon dioxide-rich exhaust gas emerging during the combustion and calcination is partially recirculated as recycled gas in the oven area. The calcined product is subsequently transported over a lock arrangement (17) in a second oven area (3) containing a cooling zone (19). The atmosphere of the oven area is separated from the atmosphere of first oven area in flow-tight manner and the cooling of the calcined product is carried out in the cooling zone through thermal contact with the cooling medium. The cooling medium of the oven area passes in a direction opposite to the conveying direction of the calcined product and is supplied to a cooling device after passing through the second oven area. The cooled cooling medium is partially supplied again to the second oven area for cooling the product. The cooling medium kicks after passing through the second oven area in heat exchange with the recycled gas of the first oven area. Air, inert gas such as nitrogen or noble gas or a gas mixture existing predominantly out of inert gases is used as cooling medium. The carbon dioxide contained in the first oven area is partially separated and supplied to sequestration. A carbon source is used as fuel in the first oven area and oxygen or oxygen-rich gas is used as oxidation agent. An independent claim is included for a device for burning limestone or other carbonates.