System and method for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud

Patent metadata

Field	Value
Publication number	US-10843131-B2
Application number	US-201916705361-A
Country	US
Kind code	B2
Filing date	Dec 6, 2019
Priority date	Dec 6, 2018
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

The present invention relates to a system and method for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud, and belongs to the recycling and environmental protection technology field. The system includes a desulfurization spray tower, an ozone generator, a denitration spray tower, a slurry mixing tank, a slurry storage tank, a vacuum filter, an ammonia water neutralization tank, an aluminum hydroxide precipitation tank, an ammonia water tank, an aluminum hydroxide storage tank, a filter press, an ammonia distillation tower, a dephlegmator, a cooler, a concentrated ammonia water storage tank, a gypsum precipitation tank, and an anaerobic biochemical pool. In the present invention, red mud slurry is used for desulfurization and denitrification treatment of flue gas to remove SO2 and NO in the flue gas, so that SO2 and NO in the flue gas reach an emission standard.

First claim

What is claimed is:

1. A system for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud, comprising a desulfurization spray tower, an ozone generator, a denitration spray tower, a slurry mixing tank, a slurry storage tank, a vacuum filter, an ammonia water neutralization tank, an aluminum hydroxide precipitation tank, an ammonia water tank, an aluminum hydroxide storage tank, a filter press, an ammonia distillation tower, a dephlegmator, a cooler, a concentrated ammonia water storage tank, a gypsum precipitation tank, and an anaerobic biochemical pool, wherein
an air blower is arranged at a flue gas inlet end at the bottom of the desulfurization spray tower; a liquid outlet end at the bottom of the desulfurization spray tower is communicated with a spray nozzle communication pipeline at the top of the desulfurization spray tower through a circulation pipeline I; a circulating pump I is arranged on the circulation pipeline I; a flue gas outlet end at a top end of the desulfurization spray tower is communicated with a flue gas inlet end of the denitration spray tower through a flue gas conveying pipeline I; an ozone outlet end of the ozone generator is communicated with the flue gas conveying pipeline I through an ozone conveying pipeline; a liquid inlet at the bottom of the desulfurization spray tower is communicated with a liquid outlet at the bottom of the denitration spray tower through a slurry pipeline I; a liquid discharge port at the bottom of the desulfurization spray tower is communicated with a liquid inlet of the slurry storage tank through a slurry pipeline II; a liquid outlet of the slurry storage tank is communicated with a liquid inlet of the vacuum filter through a slurry pipeline IV; a slurry pump is arranged on the slurry pipeline IV; a liquid outlet of the vacuum filter is communicated with a liquid inlet of the ammonia water neutralization tank through a liquid conveying pipeline I; a liquid outlet of the ammonia water neutralization tank is communicated with a liquid inlet of the aluminum hydroxide precipitation tank through a liquid conveying pipeline II; a liquid outlet end at the top of the aluminum hydroxide precipitation tank is communicated with a liquid inlet of the ammonia water tank through a liquid conveying pipeline III; a slurry outlet at the bottom of the aluminum hydroxide precipitation tank is communicated with a feed port of the aluminum hydroxide storage tank through an aluminum hydroxide slurry conveying pipeline; the aluminum hydroxide storage tank is communicated with the filter press through a screw filter pump; a liquid outlet of the filter press is communicated with a liquid inlet of the ammonia water tank through a liquid conveying pipeline IV; a liquid outlet of the ammonia water tank is communicated with the dephlegmator through a liquid conveying pipeline V; an ammonia pump is arranged on the liquid conveying pipeline V; a liquid outlet of the dephlegmator is communicated with a liquid inlet at the top of the ammonia distillation tower through the slurry pipeline IV; a gas outlet at the top of the ammonia distillation tower is communicated with a gas inlet of the dephlegmator through a flue gas conveying pipeline II; a gas outlet of the dephlegmator is communicated with an air inlet end of the through a flue gas conveying pipeline III; the cooler is communicated with concentrated ammonia water through a slurry pipeline V; the concentrated ammonia water is communicated with the ammonia water neutralization tank through a slurry pipeline VI; a bottom part of the ammonia distillation tower is communicated with the gypsum precipitation tank through a slurry pipeline VII; an outlet of the gypsum precipitation tank is communicated with the anaerobic biochemical pool through a slurry pipeline VIII; and a slurry outlet of the anaerobic biochemical pool is communicated with a feed end of the slurry mixing tank through a slurry pipeline IX; and
a liquid outlet end at the bottom of the denitration spray tower is communicated with a spray nozzle communication pipeline at the top of the denitration spray tower through a circulation pipeline II; a circulating pump II is arranged on the circulation pipeline II; a liquid inlet at the bottom of the denitration spray tower is communicated with a liquid discharge port of the slurry mixing tank through a slurry pipeline III; and a feed pump is arranged on the slurry pipeline III.

2. The system for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud according to claim 1 , wherein each of the circulation pipeline I, the circulation pipeline II, the flue gas conveying pipeline I, the flue gas conveying pipeline II, the flue gas conveying pipeline III, the ozone conveying pipeline, the slurry pipeline I, the slurry pipeline II, the slurry pipeline III, the slurry pipeline IV, the slurry pipeline V, the slurry pipeline VI, the slurry pipeline VII, the slurry pipeline VIII, the slurry pipeline IX, the liquid conveying pipeline I, the liquid conveying pipeline II, the liquid conveying pipeline III, the liquid conveying pipeline IV, the liquid conveying pipeline V, and the aluminum hydroxide slurry conveying pipeline is provided with a valve.

3. A method for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud, wherein the system for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud according to claim 1 is used, and specific steps of the method are as follows:
(1) adding red mud into the slurry mixing tank and conducting slurry mixing on the red mud and backwater obtained through biochemical treatment in the anaerobic biochemical pool to obtain red mud slurry, and adding the red mud slurry into the denitration spray tower through the feed pump on the slurry pipeline III, conveying the red mud slurry to the spray pipeline at a top end of the denitration spray tower through the circulating pump II on the circulation pipeline II, and conveying the red mud slurry to the bottom of the desulfurization spray tower through the slurry pipeline I;
(2) conveying the red mud slurry at the bottom of the desulfurization spray tower to the spray pipeline at a top end of the desulfurization spray tower through the circulating pump I on the circulation pipeline I, introducing flue gas into the desulfurization spray tower through the air blower for conducting gas-liquid countercurrent contact desulfurization treatment with the red mud slurry to obtain desulfurized flue gas and slurry A, conveying the slurry A to the spray pipeline at the top end of the desulfurization spray tower through the circulating pump I on the circulation pipeline I to replace the red mud slurry, and conveying the desulfurized flue gas to the denitration spray tower through the flue gas conveying pipeline I;
(3) conveying ozone generated by the ozone generator to the flue gas conveying pipeline I through the ozone conveying pipeline and allowing the ozone to enter the denitration spray tower along with the desulfurized flue gas, conducting gas-liquid countercurrent contact denitrification treatment on the desulfurized flue gas, the ozone, and the red mud slurry to obtain desulfurized and denitrified flue gas and slurry B, conveying the slurry B to the spray pipeline at a top end of the denitration spray tower through the circulating pump II on the circulation pipeline II to replace the red mud slurry, conveying the slurry B to the bottom of the desulfurization spray tower through the slurry pipeline I to replace the red mud slurry, and emptying the desulfurized and denitrified flue gas;
(4) adding the slurry A obtained through circulation treatment in step (2) into the slurry storage tank through the slurry pipeline II, conveying the slurry in the slurry storage tank

Assignees

• Univ Kunming Science & Technology
• Pingxiang Huaxing Env Prot Eng Tech Co Ltd

Inventors

• Ning Ping
• Yin Liangtao
• Zhang Qiulin
• Jia Lijuan
• Yin Zaifei
• Li Bo
• Li Shaoming
• Li Bin

Classifications

• Y02P20/10

  Process efficiency · CPC title

• C01F11/464

  Sulfates of Ca from gases containing sulfur oxides · CPC title

• C01F11/38

  Preparation with nitric acid or nitrogen oxides · CPC title

• C01F7/66

  Nitrates, with or without other cations besides aluminium · CPC title

• C01F5/00

  Compounds of magnesium · CPC title