Method and facility for recovering CO2 gas in cement manufacturing facility

Patent metadata

Field	Value
Publication number	US-9446984-B2
Application number	US-201314074750-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	May 7, 2008
Publication date	Sep 20, 2016
Grant date	Sep 20, 2016

Abstract

To provide a method and facility for enabling CO 2 gas generated in a cement manufacturing facility to be separated and recovered at a high concentration. To this end, according to the present invention, the calcination of a cement material and the recovery of CO 2 gas generated in a calciner are performed by one of the following steps of: [1] superheating the cement material before calcination to at least the calcination temperature thereof in a superheating furnace and then mixing the superheated cement material with a new cement material before calcination in a mixer/calciner; [2] mixing, in the mixer/calciner, the cement material before calcination with a part of high-temperature cement clinker discharged from a cement kiln; and [3] using an externally heated calciner.

First claim

The invention claimed is:

1. A method for recovering CO 2 gas generated in a cement manufacturing plant, which comprises a first preheater, a superheating furnace, a mixer/calciner, a cement kiln, and a clinker cooler
the method comprising:
pre-heating a precalcination cement material in the first pre-heater;
supplying the precalcination cement material, which comprises limestone, SiO 2 , Al 2 O 3 and Fe 2 O 3 , to the mixer/calciner;
heating cement material, calcined by the mixer/calciner, at or above a calcination temperature in a superheating furnace by combustion in a burner with combustion air, wherein the combustion air is supplied from the clinker cooler and the combustion air enhances combustion in the superheating furnace;
introducing the cement material to the mixer/calciner, wherein a temperature in the inside of the mixer/calciner is maintained at or above the calcination temperature to calcine the precalcination cement material to yield calcined cement material and that also generates CO 2 gas that is recovered,
supplying a part of the calcined cement material to the superheating furnace, and
supplying a remaining part of the calcined cement material to the cement kiln.

2. A method for recovering CO 2 gas generated in a cement manufacturing plant, which comprises a first preheater, a superheating furnace, a mixer/calciner, a cement kiln, and a clinker cooler,
the method comprising:
supplying the precalcination cement material, which has been extracted from the first preheater, to a mixer/calciner,
introducing a part of a high-temperature cement clinker from a cement kiln into the mixer/calciner, so that after the precalcination cement material is calcined, a temperature in the inside of the mixer/calciner is maintained at the calcination temperature or above,
returning the cement clinker and the calcined cement material to the first preheater or the cement kiln, without separating the cement clinker and the calcined cement material from each other;
separating the cement clinker and the cement material from the CO 2 gas generated in the mixer/caliner,
recovering CO 2 gas generated in the mixer/calciner,
wherein in the cement manufacturing plant, the pre-calcination cement material is preheated by the first preheater, to provide preheated cement material and the cement clinker is then manufactured by feeding and burning the preheated cement material in the cement kiln having a high-temperature atmosphere, wherein the pre-calcination cement material comprises limestone, SiO 2 , AlO 3 and Fe 2 O 3 ,
wherein the cement material before calcination extracted from the first preheater and the other cement material preheated to a temperature below the calcination temperature in a second preheater provided independently of the first preheater are fed to the mixer/calciner, and wherein CO 2 gas generated in the mixer/calciner is recovered after being used as a heat source of the second preheater.

3. The method for recovering CO 2 gas generated in the cement manufacturing facility according to claim 2 , wherein the cement material calcined in the mixer/calciner and the cement clinker are returned to the first preheater or the cement kiln.

4. A method for recovering CO 2 gas generated in a cement manufacturing facility, which comprises a preheater, an externally heated calciner, a cement kiln, and a clinker cooler,
the method comprising
preheating a cement material in an externally heated calciner by indirect heat to at least a calcination temperature by combustion in a burner with combustion air, wherein the combustion air is supplied from the clinker cooler via an air feed pipe and the combustion air enhances combustion in the externally heated calciner;
feeding the preheated cement material to the externally heated calciner to calcine the cement material thereby yielding calcined cement material and generating CO 2 gas;
separating the calcined cement material and the CO 2 gas;
returning the separated cement material to the preheater or the cement kiln,
recovering the CO 2 gas.

5. A method for recovering CO 2 gas generated in a cement manufacturing plant, which comprises a first preheater, a superheating furnace, a mixer/calciner, and a cement kiln,
the method comprising:
pre-heating a precalcination cement material in the first pre-heater;
supplying the precalcination cement material, which comprises limestone, SiO 2 , Al 2 O 3 and Fe 2 O 3 , to the mixer/calciner;
heating cement material at or above a calcination temperature in a superheating furnace;
introducing the cement material to the mixer/calciner, wherein a temperature in the inside of the mixer/calciner is maintained at or above the calcination temperature to calcine the precalcination cement material to yield calcined cement material and that also generates CO 2 gas that is recovered,
supplying a part of the calcined cement material to the superheating furnace, and
supplying a remaining part of the calcined cement material to the cement kiln thereby generating exhaust gas, wherein all or a portion of the exhaust gas from the cement kiln is fed to the superheating furnace and fed again to the first preheater.

6. A method for recovering CO 2 gas generated in a cement manufacturing facility, which comprises a preheater, an externally heated calciner and a cement kiln,
the method comprising
preheating a cement material in an externally heated calciner by indirect heat to at least a calcination temperature by combustion in a burner;
feeding the preheated cement material to the externally heated calciner to calcine the cement material thereby yielding calcined cement material and generating CO 2 gas and exhaust gas;
separating the calcined cement material and the CO 2 gas;
returning the separated cement material to the preheater or the cement kiln; and
recovering the CO 2 gas,
wherein all or a portion of the exhaust gas from the cement kiln is fed into the externally heated calciner and fed again to the preheater.

7. The method for recovering CO 2 gas generated in a cement manufacturing plant according to claim 1 , wherein all or a portion of exhaust gas generated in the cement kiln is fed to the superheating furnace and fed again to the first preheater.

8. The method for recovering CO 2 gas generated in a cement manufacturing plant according to claim 4 , wherein all or a portion of exhaust gas generated in the cement kiln is fed to the externally heated calciner and fed again to the preheater.

Assignees

• Mitsubishi Materials Corp

Inventors

• Shima Hirokazu
• Motohashi Eiichi
• Wang Junzhu
• Takayama Yoshinori

Classifications

• C04B7/367 Primary

  Avoiding or minimising carbon dioxide emissions · CPC title

• Y02P40/18

  Carbon capture and storage [CCS] · CPC title

• F27B7/2041

  consisting of at least two strings of cyclones with two different admissions of raw material · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• C04B7/44

  Burning; Melting · CPC title