Method for regenerating SCR denitration catalyst assisted by microwaves and device therefor

Patent metadata

Field	Value
Publication number	US-9533259-B2
Application number	US-201315028373-A
Country	US
Kind code	B2
Filing date	Oct 9, 2013
Priority date	Oct 9, 2013
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

Disclosed is a method for regenerating a SCR denitration catalyst assisted by microwaves. The method comprises: (1) a poisoned SCR denitration catalyst is immersed in deionized water, and the SCR denitration catalyst is cleaned by a bubbling method; (2) the SCR denitration catalyst is transferred to a container containing a pore-expanding solution for a soaking treatment; (3) the SCR denitration catalyst is transferred to a microwave device and treated for 1-10 minutes; (4) the SCR denitration catalyst is transferred to a container with an activating liquid and impregnated for 1-4 hours; (5) the SCR denitration catalyst is dried with microwaves for 1-20 minutes; and (6) the SCR denitration catalyst is calcined under conditions of 500-600° C. for 4-7 hours. The present invention has readily available raw materials, is simple and energy-saving in device and process, and is suitable for industrial scale regeneration. The catalyst treated by the method of the present invention has the advantages of loose pore channels, obviously optimized pore structures, significantly improved catalyst surface conditions, high activity, and good economic benefits.

First claim

The invention claimed is:

1. A method for regenerating a selective catalytic reduction (SCR) denitration catalyst assisted by microwaves, comprising:
(1) immersing a poisoned SCR denitration catalyst in deionized water, and cleaning the SCR denitration catalyst by a bubbling method for 10-30 minutes;
(2) transferring the SCR denitration catalyst from step (1) to a container containing a pore-expanding solution and conducting a soaking treatment for 10-30 minutes;
(3) transferring the SCR denitration catalyst from step (2) to a microwave device and treating the SCR denitration catalyst by microwave for 1-10 minutes;
(4) transferring the SCR denitration catalyst from step (3) to a container with an activating liquid and impregnating the SCR denitration catalyst for 1-4 hours;
(5) transferring the SCR denitration catalyst from step (4) to a microwave device and drying the SCR denitration catalyst for 1-20 minutes;
(6) transferring the SCR denitration catalyst from step (5) to a calcining device and calcining the SCR denitration catalyst under conditions of 500-600° C. for 4-7 hours.

2. The method according to claim 1 , wherein the pore-expanding solution is an aqueous solution of a solvent with a loss tangent greater than 0.174.

3. The method according to claim 2 , wherein the aqueous solution volume concentration of the solvent is 1-9% when the loss tangent of the solvent is greater than 1.3, and the aqueous solution volume concentration of the solvent is 10-90% when the loss tangent of the solvent is less than 1.3.

4. The method according to claim 2 , wherein the solvent with the loss tangent greater than 0.174 is selected from ethylene glycol aqueous solution, ethanol aqueous solution, dimethyl sulfoxide aqueous solution, methanol aqueous solution or acetic acid aqueous solution.

5. The method according to claim 4 , wherein concentration of the ethylene glycol aqueous solution, ethanol aqueous solution, dimethyl sulfoxide aqueous solution, methanol aqueous solution and acetic acid aqueous solution is 1-9%, 10-90%, 1-9%, 10-90% and 10-50%, respectively.

6. The method according to claim 1 , wherein the activating liquid is vanadate solution, tungstate solution or a mixture of vanadate solution and tungstate solution, in which the molar concentration of vanadium and tungsten is 0.01-0.4 mol/L and 0.1-2 mol/L, respectively.

7. The method according to claim 1 , wherein the bubbling in step (1) is pulse bubbling and the air source of bubbling is compressed air.

8. The method according to claim 1 , wherein the microwave power density and frequency in step (3) and (5) are 20-100 kW/m 3 and 2450 MHz, respectively.

9. A device for the method in claim 1 , wherein the device comprises following units in a serial connection: a bubbling cleaning unit, a pore-expanding impregnating unit, a first microwave treatment unit, an activating liquid impregnating unit, a second microwave treatment unit and a calcining unit; as well as manipulators transferring SCR denitration catalyst between adjacent units.

10. The device according to claim 9 , wherein the bubbling cleaning unit comprises a bubbling cleaning pool, a bubbler, an air compressor pump, a liftable and lowerable transmission belt, a deionized water supply pipe and a waste liquid discharge pipe, wherein the bubbler is positioned at bottom of the bubbling cleaning pool and connected with the air compressor pump; the liftable and lowerable transmission belt is mounted in the bubbling cleaning pool; the deionized water supply pipe is connected to a top of the bubbling cleaning pool; and the waste liquid discharge pipe is connected to a bottom of the bubbling cleaning pool;
the pore-expanding impregnating unit comprises a pore-expanding solution impregnating pool, a liftable and lowerable transmission belt, a pore-expanding solution supply pipe and a waste liquid discharge pipe, wherein the liftable and lowerable transmission belt is mounted in the pore-expanding solution impregnating pool; the pore-expanding solution supply pipe is connected to a top of the pore-expanding solution impregnating pool; and the waste liquid discharge pipe is connected to a bottom of the pore-expanding solution impregnating pool;
both the first microwave treatment unit and the second microwave treatment unit comprise a liftable and lowerable microwave oven with a conveyor belt at the bottom;
the activating liquid impregnating unit comprises an activating liquid impregnating pool, an activating liquid supply pipe, a liftable and lowerable transmission belt and a waste liquid discharge pipe, wherein the liftable and lowerable transmission belt is mounted in the activating liquid impregnating pool; the activating liquid supply pipe is connected to a top of the activating liquid impregnating pool; and the waste liquid discharge pipe is connected to a bottom of the activating liquid impregnating pool;
the calcining unit comprises a calcinator.

11. The method according to claim 3 , wherein the solvent with the loss tangent greater than 0.174 is selected from ethylene glycol aqueous solution, ethanol aqueous solution, dimethyl sulfoxide aqueous solution, methanol aqueous solution or acetic acid aqueous solution.

12. The method according to claim 2 , wherein the activating liquid is vanadate solution, tungstate solution or a mixture of vanadate solution and tungstate solution, in which the molar concentration of vanadium and tungsten is 0.01-0.4 mol/L and 0.1-2 mol/L, respectively.

13. The method according to claim 2 , wherein the bubbling in step (1) is pulse bubbling and the air source of bubbling is compressed air.

14. The method according to claim 2 , wherein the microwave power density and frequency in step (3) and (5) are 20-100 kW/m 3 and 2450 MHz, respectively.

15. The method according to claim 3 , wherein the activating liquid is vanadate solution, tungstate solution or a mixture of vanadate solution and tungstate solution, in which the molar concentration of vanadium and tungsten is 0.01-0.4 mol/L and 0.1-2 mol/L, respectively.

16. The method according to claim 3 , wherein the bubbling in step (1) is pulse bubbling and the air source of bubbling is compressed air.

17. The method according to claim 3 , wherein the microwave power density and frequency in step (3) and (5) are 20-100 kW/m 3 and 2450 MHz, respectively.

Assignees

• Univ Zhejiang

Inventors

• Gao Xiang
• Luo Zhongyang
• Cen Kefa
• Ni Mingjiang
• Song Hao
• Wu Weihong
• Yu Hongmin
• Shi Zhenglun
• Zhou Jinsong
• Fang Mengxiang
• Yu Chunjiang
• Wang Shurong
• Cheng Lemin
• Wang Qinhui

Classifications

• B01J23/92

  of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 · CPC title

• B01D2257/40

  Nitrogen compounds · CPC title

• B01J23/30

  Tungsten · CPC title

• B01J38/485

  Impregnating or reimpregnating with, or deposition of metal compounds or catalytically active elements · CPC title

• B01D53/8625

  Nitrogen oxides · CPC title