CN114307520A

CN114307520A - Flue gas desulfurization device and activated carbon desulfurization method

Info

Publication number: CN114307520A
Application number: CN202210083998.0A
Authority: CN
Inventors: 孙震; 薛冬梅; 顾时雨; 王星浩
Original assignee: China India Hengsheng Beijing Trading Co ltd
Current assignee: China India Hengsheng Beijing Trading Co ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2022-04-12

Abstract

The invention discloses a flue gas desulfurization device and an active carbon desulfurization method. The discharge chamber of the first-stage adsorption column is divided into an upper discharge chamber and a lower discharge chamber. The device comprises a first-stage adsorption column, a second-stage adsorption column and an active carbon desorption tower which are connected in series. The discharge chamber of the first stage adsorption column is divided into an upper discharge chamber, an average discharge chamber and a lower discharge chamber. The flue gas desulfurization method using the device comprises a desulfurization stage and an activated carbon adsorption stage.

Description

Flue gas desulfurization device and activated carbon desulfurization method

Technical Field

The invention discloses a flue gas desulfurization device and an activated carbon desulfurization method, and particularly relates to a power plant waste gas treatment method for adsorption desulfurization by using activated carbon.

Background

For industrial flue gas, especially flue gas discharged by sintering plants and coal-fired power plants in the steel industry, the ideal situation is to use a desulfurization and denitrification device and technology to purify the flue gas, wherein the desulfurization and denitrification device comprises an adsorption column with activated carbon and a desorption column. In a desulfurization and denitrification apparatus including an activated carbon adsorption column for adsorbing pollutants including sulfur oxides, nitrogen oxides and dioxins and a desorption column (or regeneration column) for thermal regeneration of activated carbon.

The desulfurization technique using activated carbon shows some advantages and can simultaneously denitrate, remove dioxin and remove dust without forming wastewater and waste, thus being a promising method for purifying exhaust gas. The activated carbon can be regenerated at high temperature, and pollutants such as sulfur oxides, nitrogen oxides, dioxin and the like adsorbed on the activated carbon at the temperature of more than 350 ℃ can be quickly desorbed or decomposed (sulfur dioxide desorption, nitrogen oxides and dioxin decomposition). As the temperature increases, the regeneration rate of the activated carbon further increases, thereby shortening the regeneration time.

Disclosure of Invention

The invention aims to provide a flue gas desulfurization device and an active carbon desulfurization method. Activated carbon is added to the adsorption column through the top of the column and moves downward by gravity and a drain at the bottom of the column. And conveying the activated carbon from the desorption column to the adsorption column through an activated carbon conveyor, discharging the saturated activated carbon after adsorbing the pollutants from the bottom of the adsorption column, and conveying the discharged activated carbon to the desorption column by using the activated carbon conveyor so as to regenerate the activated carbon.

In the adsorption column, a part of SO2 in the exhaust gas is adsorbed by the activated carbon, and another part of SO2, namely SO2 on the surface of the activated carbon, is oxidized and adsorbed to form sulfuric acid according to the following formula: 2SO2+ O2+2H2O =2H2SO 4.

The function of the desorption column is to release SO2 adsorbed by the activated carbon, and the dioxin can be decomposed by more than 80 percent when the temperature in the desorption column is higher than 400 ℃ and the dioxin stays in the column for a certain time. After cooling, the activated carbon can be reused. The released SO2 can be used for producing sulfuric acid and the like, and the desorbed activated carbon is conveyed to the adsorption column through the conveying device SO as to be used for adsorbing SO2, NOx and the like again.

Drawings

FIG. 1 is a schematic diagram of a system and process for desulfurization.

Fig. 2 is a schematic view of a process of desulfurization according to a first embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 2, fig. 1 is a schematic diagram of a desulfurization process and apparatus, including a first stage adsorption column (T1) and an activated carbon regeneration column (or desorption column) (T3). The first-stage (T1) adsorption column comprises a main body (1), a hopper (2) positioned at the upper part of the first-stage (T1) adsorption column, an air inlet chamber (3), a pipeline for conveying original waste gas, a first exhaust pipe (L1), an exhaust valve (4) in a lower storage bin of the adsorption tower, an exhaust valve (5) at the bottom of an activated carbon layer, a porous plate (6) and steam chambers (a and b). The flue gas chamber is divided into an upper flue gas chamber (a) and a lower flue gas chamber (b), a second exhaust gas conduit (L2) for discharging cleaned flue gas from the upper exhaust plenum (a) communicates with the exhaust pipe, and a third exhaust gas conduit (L3) communicates with the exhaust pipe for discharging exhaust gas from the lower flue gas chamber (b) back to the upper part of the intake chamber (3), where the exhaust gas is joined or connected to the original conduit of the exhaust gas supply, i.e. the first exhaust gas conduit (L1).

The desorption column for activated carbon (T3) has a heating zone in the upper part, a buffer zone in the middle part and a cooling zone in the lower part, while a line for the input of heated gas (L1A) and a line for the output of heated gas (L1B); connected to the lower and upper sides of the upper heating zone of the column, a cooling gas inlet line (L2 a) and a cooling gas outlet line (L2 b) connected to the lower and upper sides of the cooling zone at the bottom of the column, respectively, and an acid gas delivery line (L3A), which is connected to the sulfuric acid production system on the side where a buffer zone is left in the middle of the desorber (T3). Preferably, the branch pipe (L3 a ') for the heating gas is away from the starting end (or front end) of the acid gas supply pipe (L3 a), and the other end of the heating gas pipe (L3 a ') is connected to the pipe (L1 a) for supplying the heating gas or to the heating gas outlet pipe (L1 b), and the branch pipe (L3 a ') for the heating gas is used as a branch pipe from the heating gas inlet pipe (L1 a) or as a branch pipe from the pipe water to discharge the heating gas (L1 b).

Claims

1. A flue gas desulfurization device and an activated carbon desulfurization method comprise a flue gas desulfurization and denitrification device and comprise: the adsorption device comprises a first-stage adsorption column (T1) and an active carbon regeneration column (T3) (or a desorption column), wherein the first-stage adsorption column (T1) comprises a main body (1), a feed hopper (2) positioned at the upper part of the first-stage adsorption column (T1), a gas input chamber (3), a waste gas input first pipeline (L1), an inlet leading to a gas inlet chamber (3), an exhaust valve (4) in the lower feed hopper of the adsorption column, an exhaust valve (5) at the lower part of an active carbon layer, a porous plate (6) and a flue gas chamber; the steam chamber is divided into an upper steam chamber (a) and a lower steam chamber (b), a second duct (L2) for exhaust gases being connected to the exhaust duct, a third duct (L3) for flue gases, adapted to exhaust flue gases from the lower flue gas chamber (b), return to the upstream region of the flue gas chamber (3) for gas entry, and join or connect to the first flue gas duct (L1).

2. The flue gas desulfurization device and the activated carbon desulfurization method according to claim 1, characterized in that: the adsorption column (T1) of the first stage is provided with at least one layer of activated carbon; wherein the adsorption column (T1) of the first stage has two layers of activated carbon or a plurality of layers of activated carbon (A, B, C), and the two layers or the plurality of layers of activated carbon are separated by a porous plate.

3. The flue gas desulfurization device and the activated carbon desulfurization method according to claim 1, characterized in that: the vapor chamber of the first-stage adsorption column (T1) was divided into an upper gas discharge chamber (a) and a lower gas discharge chamber (b), and a second exhaust gas duct (L2) having a capability of discharging clean exhaust gas from the upper gas discharge chamber (a) was reported as an exhaust gas duct, a third duct (L3) for exhausting air, which communicates the exhaust chamber (3') from the lower steam chamber (b), the steam chamber of the first stage adsorption column (T1) is divided into an upper steam chamber (a), an average steam chamber (c) and a lower steam chamber (b) in order to allow the gas to enter the second stage or second stage adsorption column (T2), and a second exhaust pipe (L2) is provided to exhaust the purified gas from the upper flue gas chamber (a), and is communicated with an exhaust pipe, a third exhaust pipe (L3) is communicated with the exhaust pipe, and is communicated with an exhaust gas chamber (3') exhausted by a lower flue gas chamber (b) and enters the gas of the adsorption column (T2);

and a fifth exhaust pipeline (L5) which is communicated with the second exhaust pipeline (L2) and the third exhaust pipeline (L3) through a switch valve (10) by utilizing the exhaust gas exhausted from the middle steam chamber (c).

4. A desulphurisation device according to claim 3 wherein the fourth conduit (L4) for the exhaust gases is configured to remove the exhaust gas stream from the vapour chamber (9) of the second stage sorbent column (T2), which converges or connects to the second conduit (L2) for the exhaust gases and then leads to the exhaust gas duct.

5. The flue gas desulfurization device and the activated carbon desulfurization method according to claim 1, characterized in that: wherein the adsorption column (T1) of the first stage and the adsorption column (T2) of the second stage have at least one layer of activated carbon or the adsorption column (T1) of the first stage and the adsorption column (T2) of the second stage respectively have the same or different design sizes.

6. The flue gas desulfurization device and the activated carbon desulfurization method according to claim 1, characterized in that: wherein the adsorption column (T1) of the first stage and the adsorption column (T2) of the second stage have two or more layers of activated carbon (A, B, C), respectively, and the adsorption column (T1) of the first stage and the adsorption column (T2) of the second stage have the same or different design sizes by separating porous plates.

7. The flue gas desulfurization apparatus and the activated carbon desulfurization method according to claims 1 to 6, characterized in that: the at least one adsorption column of the first stage (T1) and the adsorption column of the second stage (T2) may be adjacently disposed.

8. The flue gas desulfurization device and the activated carbon desulfurization method according to claim 1, characterized in that: each steam chamber of the first-stage parallel adsorption column is divided into two chambers, namely an upper chamber and a lower chamber (a and b), or is divided into three chambers, namely an upper chamber, a middle chamber and a lower chamber (a, b and c); if the first-stage adsorption column (T1) of the double column symmetry type has two or more first-stage parallel adsorption columns, the vapor chamber of the parallel symmetrical double column used as the first-stage adsorption column is divided into two chambers, an upper chamber and a lower chamber (a, b), or is divided into three chambers, an upper chamber, a middle chamber and a lower chamber (a, b, c), respectively, and more preferably, the pipes for discharging the exhaust gas from the chambers located at the same level outside the different adsorption columns may be combined or connected with each other.

9. The flue gas desulfurization device and the activated carbon desulfurization method according to claim 1, characterized in that: wherein the desorption tower (T3) of the activated carbon is provided with a heating zone at the upper part, a buffer zone at the middle part and a cooling zone at the lower part; when a pipe (L1 a) for inputting heated gas and a pipe (L1 b) for outputting heated gas are connected to the lower side and the upper side of the heating zone in the upper part of the tower, respectively, a pipe (L2 a) for cooling gas inlet and a pipe (L2 b) for cooling gas outlet are connected to the lower part and the upper part of the lower part of the tower and the cooling zone, respectively, and a pipe (L3 a) for transporting acid gas, leaving one side of the buffer zone in the middle of the desorption tower (T3), connected to the sulfuric acid production system.