Flue gas treatment apparatus and flue gas treatment method

Patent metadata

Field	Value
Publication number	US-9573095-B2
Application number	US-201314434330-A
Country	US
Kind code	B2
Filing date	Nov 28, 2013
Priority date	Dec 26, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A flue gas treatment apparatus for removing sulfur contents contained in combustion flue gas, includes a treatment agent feeder to feed a treatment agent into a flue through which the combustion flue gas flows, a cooler to cool the combustion flue gas to which the treatment agent has been fed and condense SO 3 components in the combustion flue gas, an electric dust collection apparatus provided in the flue, a desulfurization apparatus based on a lime-gypsum process, and a circulation line for feeding a portion of the dust particles recovered by the electric dust collection apparatus into the flue that is provided on an upstream side of the cooler in the direction of flow of the flue gas for circulated use thereof as the treatment agent.

First claim

The invention claimed is:

1. A flue gas treatment apparatus for removing sulfur contents contained in combustion flue gas, comprising:
treatment agent feeding means for feeding a treatment agent into a flue through which the combustion flue gas flows;
temperature decreasing means for cooling the combustion flue gas to which the treatment agent has been fed to condense SO 3 components in the combustion flue gas;
an electric dust collection apparatus provided in a flue arranged on a downstream side of the temperature decreasing means in a direction of flow of flue gas;
a desulfurization apparatus based on a lime-gypsum process, provided downstream of the electric dust collection apparatus in a direction of flow of the flue gas; and
circulation means for feeding a portion of dust particles recovered by the electric dust collection apparatus into a flue arranged upstream of the temperature decreasing means in the direction of flow of the flue gas for circulated use of the portion of the dust particles as the treatment agent; and
control means for controlling an amount of the dust particles to be disposed of, an amount of the dust particles to be circulated for reuse, and an amount of the treatment agent to be additionally fed so as to satisfy, at a timing (t), the following expressions (I):
D ( t )= Z ( t )× Y /( X 0 +Y )× K 1 ( t )

R (SO 3 )( t )= Z ( t )− D ( t )

X (SO 3 )( t )= X 0 −R (SO 3 )( t )  (I)

wherein D(t) denotes an amount of the dust particles to be disposed of, of the dust particles recovered by the electric dust collection apparatus, Z(t) denotes the total amount of the dust particles recovered by the electric dust collection apparatus, X 0 denotes an amount of the treatment agent to be fed before circulation is started, Y denotes an amount of SO 3 to be removed from the combustion flue gas, R(SO 3 )(t) denotes an amount of the dust particles to be circulated by the circulation means for reuse, X(SO 3 )(t) denotes an amount of the treatment agent to be additionally fed, and K 1 (t) denotes a correction amount of the dust particles to be disposed of.

2. The flue gas treatment apparatus according to claim 1 , wherein the treatment agent is selected from the group consisting of calcium carbonate, activated carbon, ash, and gypsum.

3. The flue gas treatment apparatus according to claim 1 , reusing means for feeding another portion of the dust particles recovered by the electric dust collection apparatus to the desulfurization apparatus.

4. The flue gas treatment apparatus according to claim 3 , wherein the treatment agent is calcium carbonate or activated carbon.

5. A flue gas treatment apparatus for removing sulfur contents contained in combustion flue gas, comprising:
treatment agent feeding means for feeding a treatment agent into a flue through which the combustion flue gas flows;
temperature decreasing means for cooling the combustion flue gas to which the treatment agent has been fed to condense SO 3 components in the combustion flue gas;
an electric dust collection apparatus provided in a flue arranged on a downstream side of the temperature decreasing means in a direction of flow of flue gas;
a desulfurization apparatus based on a lime-gypsum process, provided downstream of the electric dust collection apparatus in a direction of flow of the flue gas;
circulation means for feeding a portion of dust particles recovered by the electric dust collection apparatus into a flue arranged upstream of the temperature decreasing means in the direction of flow of the flue gas for circulated use of the portion of the dust particles as the treatment agent;
reusing means for feeding another portion of the dust particles recovered by the electric dust collection apparatus to the desulfurization apparatus; and
control means for controlling the amount of the dust particles to be disposed of, the amount of the dust particles to be circulated for reuse, the amount of the treatment agent to be additionally fed, the amount of the dust particles to be reused in the desulfurization apparatus, and the amount of a desulfurization agent to be additionally fed to the desulfurization apparatus so as to satisfy, at a timing (t), the following expressions (II):
D ( t )= Z ( t )× Y /( X 0 +Y )× K 2 ( t )

R (SO 2 )( t )= F
R (SO 3 )( t )= Z ( t )− D ( t )− R (SO 2 )( t )

X (SO 2 )( t )= R (SO 2 )( t )× Y /( X 0 +Y )× K 2 ( t )

X (SO 3 )( t )= X 0 −R (SO 3 )( t )  (II)

wherein D(t) denotes an amount of the dust particles to be disposed of after the dust particles have been recovered by the electric dust collection apparatus, Z(t) denotes the total amount of the dust particles that have been recovered by the electric dust collection apparatus, X 0 denotes an amount of the treatment agent to be fed before circulation is started, Y denotes an amount of SO 3 to be removed from the combustion flue gas, R(SO 3 )(t) denotes an amount of the dust particles to be circulated by the circulation means for reuse, X(SO 3 )(t) denotes an amount of the treatment agent to be additionally fed, K(t) denotes a correction amount of the dust particles to be disposed of, R(SO 2 )(t) denotes an amount of the dust particles to be reused in the desulfurization apparatus, F denotes an amount required in the desulfurization apparatus, and X(SO 2 )(t) denotes an amount of a desulfurization agent to be additionally fed to the desulfurization apparatus.

6. The flue gas treatment apparatus according to claim 5 , wherein the treatment agent is calcium carbonate or activated carbon.

7. A flue gas treatment method for removing sulfur contents contained in combustion flue gas, the method comprising:
feeding a treatment agent into a flue through which the combustion flue gas flows;
cooling the combustion flue gas to which the treatment agent has been fed by using temperature decreasing means;
removing dust from the cooled combustion flue gas by using an electric dust collection apparatus; and
treating the combustion flue gas from which the dust has been removed, by using a desulfurization apparatus based on a lime-gypsum process,
wherein a portion of the dust particles recovered by the electric dust collection apparatus is fed into a flue arranged on an upstream side of the temperature decreasing means for circulated use of the portion of the dust particles as the treatment agent; and
wherein an amount of the dust particles to be disposed of, an amount of the dust particles to be circulated for reuse, and an amount of the treatment agent to be additionally fed are controlled so as to satisfy, at a timing (t), the following expressions (I):
D ( t )= Z ( t )× Y /( X 0 +Y )× K 1 ( t )

R (SO 3 )( t )= Z ( t )− D ( t )

X (SO 3 )( t )= X 0 −R (SO 3 )( t )  (I)

wherein D(t) denotes an amount of the dust particles to be disposed of, of the recovered dust particles, Z(t) denotes the total amount of the dust particles that have been recovered by the electric dust collection apparatus, X 0 denotes an amount of the treatment agent to be fed before circulation is started, Y denotes an amount of SO 3 to be removed from the combustion flue gas, R(SO 3 )(t) denotes an amount of the dust particles to be circulated for reuse, X(SO 3 )(t) denotes an amount of the treatment agent to be additionally fed, and K 1 (t) denotes a correction amount of the dust particles to be disposed of.

8. The flue gas treatment method according to claim 7 , wherein the treatment agent is selected from the group consisting of calcium carbonate, activated carbon, ash, and gypsum.

9. The combustion flue gas treatment method according to claim 7 , further comprising reusing another porti

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Yoshimoto Takashi
• Kagawa Seiji
• Fukuda Toshihiro
• Sasaki Ryozo

Classifications

• B01D2253/102

  Carbon · CPC title

• B01D53/96

  Regeneration, reactivation or recycling of reactants · CPC title

• B01D53/346

  Controlling the process · CPC title

• B01D53/508 Primary

  by treating the gases with solids · CPC title

• B01D53/50

  Sulfur oxides (B01D53/60 takes precedence) · CPC title