Method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas

Patent metadata

Field	Value
Publication number	US-10357742-B2
Application number	US-201715408600-A
Country	US
Kind code	B2
Filing date	Jan 18, 2017
Priority date	Sep 1, 2015
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

The present invention relates to a method for inhibiting the formation of dioxin-like compounds in solid waste incineration flue gases, belonging to the field of cleaning of solid waste incineration flue gases. In accordance with the present invention, when incineration flue gases cool down to 500˜450° C., the flue gases are introduced into an inhibition reactor where copper chlorides in flue gas particulates mix and react with inhibitors to convert into copper metaphosphate so as to inactivate the copper chlorides which can catalyze the formation of dioxin-like compounds and control dioxin-like compound pollutants in incineration flue gases at the source. Compared with the prior art, the invention can effectively control the main formation ways of dioxin-like compounds in solid waste incineration flue gases by optimizing inhibitors and reaction conditions. The method of the invention does not affect the residual heat utilization of solid waste incineration flue gases, so solid waste incineration has a better resource utilization effect. The ammonium dihydrogen phosphate inhibitor used in the invention has the advantages of high inhibition efficiency, strong operability, low cost and environment protection, providing the technology with good application feasibility.

First claim

What is claimed is:

1. A method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas comprising:
cooling solid waste incineration flue gas down to 500˜450° C.; uniformly mixing an inhibitor with water in a mass ratio of 1:4 to form a pulp, and atomizing and spraying the pulp into an inhibition reactor in a pulse mode at a flow rate of 10˜15 g/Nm 3 via inhibitor nozzles; and introducing the solid waste incineration flue gas into the inhibition reactor where copper chloride in particulates of the solid waste incineration flue gas mixes and reacts with the inhibitor to be converted into copper metaphosphate,
wherein the inhibitor contains ammonium dihydrogen phosphate,
the solid waste incineration flue gas is fed to an inlet nozzle at the bottom of the inhibitor inhibition reactor, and the solid waste incineration flue gas flows through the inhibitor inhibition reactor from bottom to top of the inhibitor inhibition reactor.

2. The method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas as claimed in claim 1 , wherein the inhibition reactor includes layered ceramic honeycomb packing therein,
each layer of the layered ceramic honeycomb packing has a thickness of 50˜100 mm, a hole opening ratio of 75˜85%, and a height spacing of 600˜800 mm,
the inhibitor is sprayed into the inhibition reactor via inhibitor nozzles in a wall of the inhibition reactor between two layers of the layered ceramic honeycomb packing, and,
the solid waste incineration flue gas has a retention time of 1.5˜2.5 s in the inhibition reactor.

3. The method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas as claimed in claim 2 , wherein the inhibition reactor is cylindrical with a height-to-diameter ratio of 4.5:1˜5.5:1.

4. The method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas as claimed in claim 2 , wherein holes of each layer of the layered ceramic honeycomb packing holes have a plane shape of regular quadrangle or hexagon with a side length being 50˜100 mm.

5. The method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas as claimed in claim 2 , wherein the inhibition reactor wall is provided with pressure steam nozzles to blow off ash deposits on a surface of the layered ceramic honeycomb packing.

6. The method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas as claimed in claim 2 , wherein a gas flow distribution plate is arranged near an inlet of the inhibition reactor and is configured to uniformly distribute the solid waste incineration flue gas.

7. The method of inhibiting formation of dioxins and dioxin-like compounds in solid waste incineration flue gas as claimed in claim 5 , wherein the pressure steam nozzles are in a wall of the inhibition reactor between two layers of the layered ceramic honeycomb packing.

Assignees

• Univ Tongji

Inventors

• He Pinjing
• Zhang Hua
• Wang Sijia
• Shao Liming
• Lyu Fan

Classifications

• B01D53/78 Primary

  with gas-liquid contact · CPC title

• B01D2251/206

  Ammonium compounds · CPC title

• B01D2257/204

  Inorganic halogen compounds · CPC title

• B01D2251/61

  Phosphates · CPC title

• B01D2258/0291

  from waste incineration plants · CPC title