Method and facility for recovering CO2 gas in cement manufacturing facility

A facility for recovering CO2 gas generated in a cement manufacturing plant, the facility comprising:

• an extraction line, in which pre-calcination cement material is extracted from a first preheater;
• a mixer/calciner, into which the pre-calcination cement material extracted from the extraction line is introduced;
• a superheating furnace, in which partially-calcined cement material fed from the mixer/calciner is superheated to at least a calcination temperature of the pre-calcination cement material to give a calcined cement material;
• a circulation line, in which the cement material superheated in the superheating furnace is returned to the mixer/calciner, and in which the partially-calcined cement material in the mixer/calciner is sent to the superheating furnace;
• a return line, in which a part of the calcined cement material is returned to a first preheater or a cement kiln;
• and
• a CO2 gas exhaust pipe, in which CO2 gas generated in the mixer/calciner is recovered,
• wherein the cement manufacturing plant comprises the first preheater, in which the pre-calcination cement material is preheated, and the cement kiln, in which the pre-calcination cement material preheated by the first preheater is burned,
• wherein the facility is one in which CO2 gas generated in the cement manufacturing plant is recovered;
• and
• a second preheater, provided independently of the first preheater, in which a second pre-calcination cement material is preheated;
• and
• a transfer pipe, in which the second pre-calcination cement material preheated by the second preheater is fed to the mixer/calciner,
• wherein the CO2 gas exhaust pipe extended from the mixer/calciner is introduced into the second preheater as a heat source of the second preheater.

A method for recovering CO2 gas generated in a cement manufacturing plant, the method comprising,

• after calcining a pre-calcination cement material in a mixer/calciner, the inside of which mixer/calciner is maintained at at least a calcination temperature of the pre-calcination cement material by feeding the pre-calcination cement material extracted from a first preheater to the mixer/calciner and by introducing a part of a high-temperature cement clinker discharged from a cement kiln into the mixer/calciner, to give a calcined cement material,
• returning at least the calcined cement material to the first preheater or the cement kiln;
• recovering CO2 gas generated in the mixer/calciner,
• separating the calcined cement material, calcined in the mixer/calciner, and the cement clinker from each other, to give a separate cement material;
• and
• returning the separated cement material to the first preheater or the cement kiln,
• wherein the cement manufacturing plant is one in which the pre-calcination cement material is preheated by the first preheater, to give preheated cement material, and in which cement clinker is then manufactured by feeding and burning the preheated cement material in the cement kiln having a high-temperature atmosphere.

A method for recovering CO2 gas generated in a cement manufacturing plant, the method comprising,

• after calcining a pre-calcination cement material in a mixer/calciner, the inside of which mixer/calciner is maintained at at least a calcination temperature of the pre-calcination cement material by feeding the pre-calcination cement material extracted from a first preheater to the mixer/calciner and by introducing a part of a high-temperature cement clinker discharged from a cement kiln into the mixer/calciner, to give a calcined cement material,
• returning at least the calcined cement material to the first preheater or the cement kiln;
• recovering CO2 gas generated in the mixer/calciner,
• feeding the pre-calcination cement material extracted from the first preheater and a second pre-calcination cement material preheated to a temperature below a calcination temperature of the second pre-calcination cement material in a second preheater, provided independently of the first preheater, to the mixer/calciner;
• recovering CO2 gas generated in the mixer/calciner after employing the CO2 gas as a heat source of the second preheater;
• separating the calcined cement material, calcined in the mixer/calciner, and the cement clinker are separated from each other, to give a separated cement material;
• and
• returning the separated cement material to the first preheater or the cement kiln,
• wherein the cement manufacturing plant is one in which the pre-calcination cement material is preheated by the first preheater, to give preheated cement material, and in which cement clinker is then manufactured by feeding and burning the preheated cement material in the cement kiln having a high-temperature atmosphere.

A facility for recovering CO2 gas generated in a cement manufacturing plant, the facility comprising:

• an extraction line, in which pre-calcination cement material from a first preheater is extracted;
• a mixer/calciner, into which the pre-calcination cement material extracted from the extraction line and a portion of high-temperature cement clinker extracted from a cement kiln is introduced and calcined;
• a separation unit, in which calcined cement material, calcined in the mixer/calciner, is separated from the cement clinker;
• a return line, in which separated cement material, separated by the separation unit, is returned to a first preheater or the cement kiln;
• and
• a CO2 exhaust gas line, in which CO2 gas generated in the mixer/calciner is recovered,
• wherein the cement manufacturing plant comprises the first preheater for preheating the pre-calcination cement material, and the cement kiln for manufacturing cement clinker by burning the pre-calcination cement material preheated by the first preheater, and
• wherein the facility is one in which CO2 gas generated in the cement manufacturing plant is recovered.

A facility for recovering CO2 gas generated in a cement manufacturing plant, comprising:

• an extraction line, in which pre-calcination cement material is extracted from a first preheater;
• a mixer/calciner, into which the pre-calcination cement material extracted from the extraction line and a portion of high-temperature cement clinker extracted from a cement kiln, is introduced and calcined;
• a return line in which calcined cement material calcined in the mixer/calciner and the cement clinker are returned to a first preheater or the cement kiln;
• a CO2 exhaust gas line with which CO2 gas generated in the mixer/calciner is recovered,
• a second preheater, provided independently of the first preheater, in which a second pre-calcination cement material is preheated;
• and
• a transfer pipe, which feeds to the mixer/calciner, the second pre-calcination cement material preheated by the second preheater,
• wherein the CO2 exhaust gas line extended from the mixer/calciner is introduced into the second preheater as a heat source of the second preheater,
• wherein the cement manufacturing plant comprises the first preheater for preheating the pre-calcination cement material, and the cement kiln in which cement clinker is manufactured by burning the cement pre-calcination material preheated by the first preheater, and
• wherein the facility is one in which CO2 gas generated in the cement manufacturing plant is recovered.

A method for recovering CO2 gas generated in a cement manufacturing plant, the method comprising:

• after calcining a pre-calcination cement material extracted from a preheater by indirectly heating the pre-calcination cement material and a second pre-calcination cement material preheated to a temperature below a calcination temperature of the second pre-calcination cement material in a second preheater, provided independently of the preheater and comprising a plurality of stages of cyclones, to at least the calcination temperature of the second pre-calcination cement material in the externally heated calciner so as to be calcined to give a calcined cement material,
• separating the calcined cement material and the CO2 gas generated in calcination at a time of calcination from each other by the cyclones, to give separated cement material;
• returning the separated cement material to the preheater or a cement kiln;
• and
• recovering the CO2 gas after employing the CO2 gas as a heat source of the second preheater,
• wherein the cement manufacturing plant is one in which the pre-calcination cement material is preheated by the preheater and is then fed and burned in the cement kiln having a high temperature atmosphere,
• wherein the pre-calcination cement material comprises limestone, SiO2, Al2O3 and Fe2O3.

A facility for recovering CO2 gas generated in a cement manufacturing plant, the facility comprising:

• a first extraction line, in which pre-calcination cement material is extracted from the preheater;
• an externally heated calciner comprising the first extraction line introduced therein, in which the pre-calcination cement material is calcined by indirectly heating the pre-calcination cement material to at least a calcining temperature thereof, to give a calcined cement material;
• a solid-gas separation unit provided on an outlet side of the externally heated calciner, in which the calcined cement material and CO2 gas sent from the first extraction line are separated from each other;
• a return line, in which cement material separated by the solid-gas separation unit is returned to the preheater or a cement kiln;
• and
• a CO2 gas recovery line, in which the CO2 gas separated by the solid-gas separation unit is recovered,
• wherein the cement manufacturing plant comprises the preheater in which the pre-calcination cement material is preheated, and the cement kiln in which the pre-calcination cement material preheated by the preheater is burned,
• wherein the facility is one in which CO2 gas generated in the cement manufacturing plant is recovered;
• a second preheater provided independently of the preheater and comprising a plurality of stages of cyclones, in which a second pre-calcination cement material is preheated;
• a second extraction line, in which the second pre-calcination cement material preheated by the second preheater is extracted;
• and
• a circulation line connected between a discharge side of the externally heated calciner and a lower stage cyclone of the second preheater, and branched from an exhaust line of an upper stage cyclone so as to be connected to an inlet side of the externally heated calciner,
• wherein the solid-gas separation unit is the lower stage cyclone of the second preheater, and the first extraction line and the second extraction line are connected to the circulation line on an upstream side of the externally heated calciner.