Method for producing cement with separation of CO₂

摘要

A plant for producing cement clinker from calcium carbonate-containing raw meal. A preheating stage preheats the raw meal, which preheating stage is heated by exhaust gases from a following sintering stage. A stage is provided for deacidification and sintering of the raw meal. A cooling stage for the sintered meal is of at least two-stage design and has a gas separation stage for separating exhaust gases from the deacidification and sintering stage which is routed in a first gas circuit from the cement clinker cooling gas. A gas/gas heat exchanger is arranged downstream of the preheating stage in the gas flow direction, through which heat exchanger heat from the combined exhaust gases which leave the preheating stage is transferred into a gas, extracted from the gas for cooling the cement clinker, routed in a second gas circuit, for drying the raw meal in a preceding grinding stage.

主权项

1. A plant for producing cement clinker, the plant comprising:
a grinding stage to grind calcium carbonate-containing initial material into calcium carbonate-containing raw meal; a deacidifying stage to deacidify the raw meal and generate exhaust gases; a sintering stage to sinter the raw meal into cement clinker and generate exhaust gases; a combining stage to combine the exhaust gases from the sintering stage with the exhaust gases from the deacidifying stage in a first open gas circuit; a preheating stage to preheat the raw meal prior to deacidifying by the combined exhaust gases from the sintering stage and the deacidifying stage; a cooling stage to cool the cement clinker from the sintering stage, the cement clinker being cooled by circulation air in a separate second open gas circuit, wherein the circulation air becomes heated and is delivered to the grinding stage; a transferring stage to transfer heat from the combined exhaust gases from the preheating stage in the first open gas circuit to the circulation air from the grinding stage in the second open gas circuit without mixing the gases between the first and second gas circuits, such that the combined exhaust gases are cooled, and simultaneously the circulation air is reheated by the heat transfer; a combining stage, after the heat transfer, to combine the reheated circulation air with the circulation air heated in the cooling stage such that the combined circulation air is introduced into the grinding stage to dry the raw meal; a first separating stage to separate a fraction of the combined exhaust gases from the first open gas circuit, a quantity fraction of the separated fraction of the combined exhaust gases corresponding to a fraction which is newly added to the first open gas circuit in the first open gas circuit as a result of combustion and deacidification; and a second separating stage to separate a fraction of the circulation air from the second open gas circuit, a quantity fraction of the separated fraction of the circulation air corresponding to a fraction which is newly added to the second open gas circuit in the second open gas circuit as a result of atmospheric air intake at the cooling stage.