CN-122006589-A - Selective catalytic denitration pyrolysis device for coupling carbon capture

CN122006589ACN 122006589 ACN122006589 ACN 122006589ACN-122006589-A

Abstract

The invention discloses a coupling carbon capture selective catalytic denitration pyrolysis device which comprises a shell, a pyrolysis cylinder, a carbon capture cylinder and a heating cylinder, wherein the shell is a rectangular shell, a separation cavity is formed in the top of the shell, an air collection cavity is formed in the bottom of the shell, a first end of the pyrolysis cylinder stretches into the shell from the top of the shell and is communicated with the air collection cavity, the pyrolysis cylinder is arranged in the center of the shell and is used for pyrolyzing ammonium carbamate powder and conveying pyrolysis gas of carbon dioxide and ammonia generated by pyrolysis into the air collection cavity, and a slaked lime water inlet is used for conveying slaked lime water into the carbon capture cylinder so as to adsorb carbon dioxide in the pyrolysis gas entering the carbon capture cylinder from the air collection cavity. Compared with the ammonia preparation by urea, the ammonia preparation efficiency is improved by 5.4% -24.8%, the average ammonia preparation efficiency is improved by 15.60%, the ammonia preparation energy consumption is reduced by 30.6% -40.6%, and meanwhile, the denitration efficiency of the generated mixed gas entering the flue gas selective catalytic denitration reactor can be improved by 2.8% -4.2%.

Inventors

LI YUZHE
Bao Diefan
LIU LIANBO
LU DAYONG
ZHONG LI
SUN ZHONGHAO
LI WEI
RU YU

Assignees

北京华能长江环保科技研究院有限公司
华能巢湖发电有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260226

Claims (10)

1. A coupled carbon capture selective catalytic denitration pyrolysis device, comprising: the shell is a rectangular shell, a separation cavity is formed in the top of the shell, an air collection cavity is formed in the bottom of the shell, the shell is provided with a slaked lime water inlet and a mixed gas outlet which are communicated with the separation cavity, and the shell is also provided with a slaked lime water outlet and a solid outlet which are communicated with the air collection cavity; The first end of the pyrolysis cylinder stretches into the shell from the top of the shell and is communicated with the gas collection cavity, the second end of the pyrolysis cylinder is provided with a discharging opening, the pyrolysis cylinder is arranged at the center of the shell and is used for pyrolyzing ammonium carbamate powder and conveying pyrolysis gas of carbon dioxide and ammonia generated by pyrolysis into the gas collection cavity; The carbon capture cylinder is arranged in the shell and is positioned at four corners of the shell, the top end and the bottom end of the carbon capture cylinder are respectively communicated with the separation cavity and the gas collection cavity, the slaked lime water inlet is used for conveying the slaked lime water into the carbon capture cylinder so as to adsorb carbon dioxide in pyrolysis gas entering the carbon capture cylinder from the gas collection cavity, and the adsorbed pyrolysis gas is discharged through the gas mixture outlet; And the heating cylinder is arranged in the shell and positioned between two adjacent carbon trapping cylinders and is used for heating the pyrolysis cylinder to carry out pyrolysis.
2. The selective catalytic denitration pyrolysis device coupled with carbon capture according to claim 1 wherein the pyrolysis cartridge, the carbon capture cartridge, and the heating cartridge are square and equal in side length, and the pyrolysis cartridge, the carbon capture cartridge, and the heating cartridge are arranged in a matrix.
3. The coupled carbon-trap selective catalytic denitration pyrolysis device of claim 2, wherein the ratio of the height of the housing to the square cross-section side length is (5.0-6.0): 1.0.
4. The coupled carbon-trap selective catalytic denitration pyrolysis device of claim 1, wherein the pyrolysis cartridge and the carbon-trap cartridge have the same height and a height ratio to the separation chamber and the gas collection chamber is (5.0-6.0): 1.0 (1.5-2.0).
5. The selective catalytic denitration pyrolysis device coupled with carbon capture according to claim 1, wherein pyrolysis gas and the slaked lime water solution absorbed in the gas collection cavity are contacted and separated for 3s-5s.
6. The coupled carbon-trap selective catalytic denitration pyrolysis device of claim 1, wherein a residence time of pyrolysis gas in the carbon-trap cartridge is between 5s and 12s.
7. The coupled carbon-trap selective catalytic denitration pyrolysis device of claim 1, wherein the residence time of ammonium carbamate powder in the pyrolysis drum is 8s to 10s.
8. The coupled carbon-trapping selective catalytic denitration pyrolysis device of claim 1, further comprising a heating rod and a heat accumulator, wherein the heating rod is disposed in the heating cylinder and coaxially disposed with the heating cylinder, an annular cavity is defined between the heating rod and the heating cylinder, and the heat accumulator is filled in the annular cavity.
9. The coupled carbon capture selective catalytic denitration pyrolysis device of claim 1, wherein the slaked lime water outlet is in communication with the slaked lime water inlet through a circulation pump.
10. The coupled carbon-trap selective catalytic denitration pyrolysis device of claim 1, further comprising a separator plate disposed at a bottom end port of the heating cartridge.

Description

Selective catalytic denitration pyrolysis device for coupling carbon capture Technical Field The invention relates to the technical field of flue gas denitration of coal-fired power plants, in particular to a selective catalytic denitration pyrolysis device for coupling carbon capture. Background In the SCR flue gas denitration process, the selection of a reducing agent is important. The most commonly used flue gas denitration reducing agent at present is urea. Urea ammonia production technology is relatively mature and high in safety, but needs to be performed under high-temperature conditions, which results in high energy consumption cost of the denitration system. In addition, carbon dioxide in mixed gas (comprising air, carbon dioxide, ammonia and the like) generated in the traditional urea thermal decomposition process directly enters a flue gas denitration system after untreated, and can be adsorbed on the surface of a catalyst in a competitive manner with reactants, especially in a high-concentration carbon dioxide environment, so that denitration efficiency can be reduced. In the related art, aiming at the limitations of the existing urea ammonia production technology, an intermediate product ammonium carbamate in urea production is provided as a main denitration agent component, and the method has the advantage of cost. However, ammonium carbamate is easy to agglomerate in the process of being applied to flue gas selective catalytic denitration, so that the problems of pipeline blockage, difficult decomposition and the like are caused. Disclosure of Invention The present invention aims to solve at least one of the technical problems in the related art to some extent. For this reason, the embodiment of the invention provides a selective catalytic denitration pyrolysis device coupled with carbon trapping. The selective catalytic denitration pyrolysis device for coupling carbon capture comprises a shell, a pyrolysis cylinder, a carbon capture cylinder and a heating cylinder, wherein the shell is a rectangular shell, a separation cavity is arranged at the top of the shell, an air collecting cavity is arranged at the bottom of the shell, a slaked lime water inlet and a mixed gas outlet are arranged in the shell, the slaked lime water inlet and the solid outlet are communicated with the air collecting cavity, a first end of the pyrolysis cylinder stretches into the shell from the top of the shell and is communicated with the air collecting cavity, a second end of the pyrolysis cylinder is provided with a blanking port, the pyrolysis cylinder is arranged at the central position of the shell and is used for pyrolyzing ammonium carbamate powder and conveying pyrolysis gas of carbon dioxide and ammonia gas generated by pyrolysis into the air collecting cavity, the carbon capture cylinder is arranged in the shell and is positioned at four corners of the shell, the top end and the bottom of the carbon capture cylinder are respectively communicated with the separation cavity and the air collecting cavity, the slaked lime water inlet is used for conveying raw lime water into the shell and is communicated with the air collecting cavity, the second end of the pyrolysis cylinder is provided with a blanking port, the pyrolysis cylinder is arranged at the central position of the shell, the pyrolysis cylinder is used for absorbing and the carbon dioxide gas is discharged from the two adjacent to the pyrolysis cylinder, and the heating cylinder is arranged in the air collecting cavity is heated, and is arranged in the air collecting cavity and is heated between the two adjacent cylinder and is used for collecting and discharged. In some embodiments, the pyrolysis cartridge, the carbon capture cartridge, and the heating cartridge are square and equal in side length, and the pyrolysis cartridge, the carbon capture cartridge, and the heating cartridge are in a matrix arrangement. In some embodiments, the ratio of the height of the housing to the square cross-section side length is (5.0-6.0): 1.0. In some embodiments, the pyrolysis drum and the carbon capture drum are the same height and the ratio of the height to the separation chamber and the gas collection chamber is (5.0-6.0) 1.0 (1.5-2.0). In some embodiments, the contact separation time of the pyrolysis gas and the slaked lime water solution absorbed in the gas collection cavity is 3s-5s. In some embodiments, the residence time of the pyrolysis gas within the carbon capture cylinder is between 5s and 12s. In some embodiments, the residence time of the ammonium carbamate powder in the pyrolysis drum is 8s to 10s. In some embodiments, the selective catalytic denitration pyrolysis device coupled with carbon capture according to the embodiments of the present invention further includes a heating rod and a heat accumulator, the heating rod is disposed in the heating cylinder and is disposed coaxially with the heating cylinder, an annular cavity is defined between the heat