Carbon dioxide circulation method, useful for producing cement clinker and electrical energy, comprises superheating a carbon dioxide flow in a boiler unit/exchanger, and contacting the overheated carbon dioxide flow with calcium carbonate

摘要

The carbon dioxide circulation method comprises: superheating a carbon dioxide flow at 1200-1400[deg] C in a boiler unit/exchanger (SCO2), contacting the overheated carbon dioxide flow with calcium carbonate, and providing thermal energy necessary to the decomposition of calcium carbonate into calcium oxide and carbon dioxide at a temperature of 900[deg] C; separating calcium oxide and carbon dioxide followed by cooling 400-900[deg] C of carbon dioxide by heat exchange with a flow of air at a room temperature; and de-dusting the resulting carbon dioxide flow in a high-output filter. The carbon dioxide circulation method comprises: superheating a carbon dioxide flow at 1200-1400[deg] C in a boiler unit/exchanger (SCO2), contacting the overheated carbon dioxide flow with calcium carbonate, and providing thermal energy necessary to the decomposition of calcium carbonate into calcium oxide and carbon dioxide at a temperature of 900[deg] C; separating calcium oxide and carbon dioxide followed by cooling 400-900[deg] C of carbon dioxide by heat exchange with a flow of air at a room temperature; and de-dusting the resulting carbon dioxide flow in a high-output filter. The resulting carbon dioxide flow is partly given in circulation or partly extracted from the cycle, then cooled at 120-180[deg] C and sent to storage or to another use. The superheating step is carried out by a combustion air preheated at 450-600[deg] C in an exchanger and the recovery of the significant heat of gases from an oven for cement clinker. The combustion air is an air coming from the separating phase. A part of the carbon dioxide flow coming from the de-dusting phase corresponds to the quantity of carbon dioxide produced by the decomposition of calcium carbonate. An independent claim is included for an apparatus for production of cement clinker.