CN103657400A

CN103657400A - Integrated engineering system for purifying flue gas by LSCO (low-temperature selectivity catalytic oxygen)

Info

Publication number: CN103657400A
Application number: CN201210364328.2A
Authority: CN
Inventors: 张继惟
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-09-24
Filing date: 2012-09-24
Publication date: 2014-03-26

Abstract

The invention relates to a special gas humidifying, mixing and injecting system, a catalyst tower, special catalysts and an absorption tower for absorbing SO2, NOx and Hg particles in flue gas simultaneously. Effective ammonium sulfate and ammonium nitrate can be generated in a tower in which ammonia hydroxide is taken as an absorbent. Compared with the prior art, such as an SCR (Selective Catalytic Reduction) method, the system has the following beneficial effects: (1) the temperature greater than 200 DEG C is not required when the system operates within a conventional kiln flue gas temperature range (60-150 DEG C), so that the existing boiler structure is not required to be transformed, and only the flue channel part needs to be transformed; (2) byproducts are ammonium sulfate and ammonium nitrate fertilizers, and are not required to be converted into N2 by reduction, so that the system has considerable running benefit; (3) the system is long in service life, good in reliability, low in investment, and high in NOx removing efficiency; (4) an oxidant is generally compressed air, and expensive high-value oxidants such as hydrogen peroxide and ozone are not required.

Description

The engineering of integrating system of LSCO (cryogenic selective Catalytic Oxygen method) purifying smoke

Technical field

The present invention relates to field of Environment Protection, be specifically related to the purification techniques system of flue gas

Background technology

At present, at Chinese denitration technology, be SCR and SNCR method, major defect is:

(1) need to, through row transformation on complete boiler, need to destroy original boiler;

(2) need under hot conditions, work, SCR method: 280～420 ℃, SNCR method: 930～1093 ℃, system and material are had higher requirements;

(3) in SCR catalyst, contain highly toxic V2O5 and easily cause secondary pollution, need to spend the micro-useless processing of large price;

(4) work under bad environment, easily failure, the life-span is short, and catalyst General Life is 16000h left and right only;

(5) operating cost is high: owing to adopting selective catalytic reduction method need to spend a large amount of ammonia as reducing agent, and the NO in reduction flue gas _xfor N ₂discharge;

(6) need comparatively accurate control and purging system, investment is large.

Summary of the invention

The object of the invention is the defect for existing SCR method, in principle, from the SCR of SCR method and transfer selective catalytic oxidation path to, with cheap compressed air, be primary oxidant, thereby overcome the defect of SCR method:

(1) serviceability temperature is 60～150 ℃, does not need 280 ℃ of high-temperature flue gas conditions of >, thereby does not need to transform original boiler.

(2) accessory substance is sulfate, nitrate, with ammonia absorption, generates sulphur ammonium, and ammonium nitrate chemical fertilizer has better operation income;

(3) desulphurization denitration is used same set of absorption tower, can further reduce particle concentration and remove the Toxics such as Hg;

(4) catalyst good reliability, the life-span is long, does not need expensive control and purging system;

(5) one-time investment is little.

Can be widely used in boiler and Industrial Stoves as field gas cleanings such as (sintering furnace, cement kiln, glass furnaces).

Technical scheme of the present invention is:

The engineering of integrating system of this LSCO cryogenic selective catalytic oxidation purifying smoke is by gas mixer, SCO catalytic oxidation tower, integrated desulfurization, denitration absorption tower and corresponding supply system, as compressed air, after ammoniacal liquor and other absorbent storing supply system forms 1 dedusting of flue gas Self-duster and the mist being formed by compressed air 3 and promoter gas 4 of ejection in gas mixer 2 be mixed into static mixer 5 and further mix after in catalytic oxidation tower 6, the NO under catalyst 7 acts in flue gas is oxidized to NO ₂with other NO _xwith flue gas, enter in bubbling absorption column 8 and the absorption liquid raw corresponding nitrate of 10 reaction and nitrite, the simultaneously SO in flue gas ₂also be absorbed in the lump, simultaneously absorbed also have solid particulate matter and other material as Hg etc., and the flue gas after purification enters chimney 12 through demister 9 by air-introduced machine 11 and discharges.

Accompanying drawing 1, does not comprise the technical scheme of the chemical fertilizer production system after ammonia absorption.

Accompanying drawing explanation

Fig. 1 is system architecture schematic diagram of the present invention, wherein:

1---deduster, 2---gas mixer, 3---air compressor (station), 4---promoter vaporizer, 5---flue gas static mixer, 6---SCO catalytic oxidation tower, 7---catalyst, 8---integrated absorption tower, 9---demister, 10---absorption liquid, 11---air-introduced machine, 12---chimney, 13---valve, 14---flue gas.

The specific embodiment

Claims

1. use process for selective catalytic oxidation to remove a water-fast NO in flue gas, the compressed air that makes it to pass into after humidification under catalyst condition is oxidized, and generates water-soluble NO ₂with high oxynitride, comprising: compressed air and humidifying method, gas jet-mixing system, and with cyclone mode mixed flue gas, through mixing grid 5, enter the special catalytic reactor that oxidation catalyst 7 is housed 6, the NO oxidation by air in flue gas, and other materials are as SO ₂oxidized hardly, it is characterized in that: the compressed air after humidification sprays in flue by a kind of spraying system after gas mixer and flue gas 14 mixes, and the NO in catalytic reactor and in flue gas plays selective catalytic oxidation reaction and generates water-soluble NO _xthereby, in absorption tower 8, be cleaned removal.

2. according to above-mentioned (1) described system, it is characterized by: use the compressed air after humidification, if desired (as low SO ₂environment) can increase part ozone, at high concentration CO ₂under condition, through special mixed flow and catalyst condition, the NO in oxidation kiln gas becomes the NO that can be absorbed by water, alkaline solution ₂and NO _x.