CN109173665A - A kind of method of CFB boiler denitration - Google Patents
A kind of method of CFB boiler denitration Download PDFInfo
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- CN109173665A CN109173665A CN201811033540.4A CN201811033540A CN109173665A CN 109173665 A CN109173665 A CN 109173665A CN 201811033540 A CN201811033540 A CN 201811033540A CN 109173665 A CN109173665 A CN 109173665A
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- boiler
- ammonium hydroxide
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- ammonia
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/77—Liquid phase processes
- B01D53/78—Liquid phase processes with gas-liquid contact
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
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- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
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- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Treating Waste Gases (AREA)
Abstract
The present invention relates to field Denitration in Boiler methods, more particularly to a kind of method of CFB boiler denitration comprising following steps: (1) opening spray gun atomization compressed air hand-operated valve, gun inlets ammonia water pipeline hand-operated valve, ammonium hydroxide pump discharge hand-operated valve and return valve, dilution water (desalted water) pump discharge valve and return valve；(2) start aqua ammonia pump, adjust return valve and control its pressure in (0.4-0.6) MPa；(3) starting dilution fresh water pump, adjusts return valve, controls its pressure in (0.4-0.6) MPa；It is adjusted according to ammonia concn control for 10%；(4) hand-operated valve of distributor to separate unit boiler is opened, ammonium hydroxide enters the spray gun of each boiler, sprays into boiler；(5) according to ammonium hydroxide flow and concentration difference ammonium hydroxide and clear water flow, and the content of flue gas nitrogen oxide is combined to be adjusted, until subject to emission compliance.The present invention monitors the NOx content in tail gas on-line using equipment advantage, and by realizing automation interlocked control NH3 the amount of injection, guarantees NOx and NH3 reaction density, it is ensured that tail gas qualified discharge.
Description
Technical field
The present invention relates to CFB boiler method of denitration.
Background technique
With rapid changepl. never-ending changes and improvements with living environment with the development of economy, people more pay close attention to environmental protection, Environmental
Protection is increasingly paid attention to, and in chemical industry, SO2 and NOx in boiler in outlet tail gas are the emphasis of country's concern, and pass
The burning boiler steam generating device of system is undesirable to NOx treatment effect, to guarantee 2 × 45t/ of Xiangyang Longmang Titanium Industry Co., Ltd.
H CFB boiler tail gas qualified discharge generates the principle of NOx according to live boiler fired coal and main component is analyzed, and
In conjunction with actual conditions to three kinds of current low NOx combusting technology, SCR gas denitrifying technology, SNCR gas denitrifying technology denitration works
Skill is investigated and compares, and selects to determine boiler exhaust gas treatment process of the SNCR gas denitrifying technology as our company, but the skill
Art has strict control to temperature in burner hearth of NH3 and NOx and concentration, if control is improper will to cause secondary pollution, on solving
Problem is stated, the efficiency for maximizing raising boiler exhaust gas NOx processing studies it.
SNCR selective non-catalytic reduction refers to without using catalyst, and reduction is sprayed into burner hearth or flue
Agent, the NOx in flue gas be directly reduced to a kind of technique of nitrogen and water currently common SNCR technology be reducing agent (such as
Ammonia ammonium hydroxide urea liquid) region that temperature is 800-1100 DEG C is sprayed into, reducing agent rapid thermal decomposition is simultaneously abundant in flue gas
Diffusion simultaneously selectively carries out react with the NOx in flue gas generation N2 and H2O, in the process reducing agent substantially not with
O2 reaction in flue gas.SNCR denitration efficiency highest can achieve 80% or more
Summary of the invention
To solve temperature and concentration control improper by caused by secondary pollution of the NH3 and NOx in burner hearth in SNCR technology,
The efficiency for improving boiler exhaust gas NOx processing is maximized, the present invention provides a kind of methods of CFB denitration:
(1) spray gun atomization compressed air hand-operated valve, gun inlets ammonia water pipeline hand-operated valve, ammonium hydroxide pump discharge hand-operated valve are opened and is returned
Flow valve, dilution water (desalted water) pump discharge valve and return valve；
(2) start aqua ammonia pump, adjust return valve and control its pressure in (0.4-0.6) MPa；
(3) starting dilution fresh water pump, adjusts return valve, controls its pressure in (0.4-0.6) MPa；It is according to ammonia concn control
10% is adjusted；
(4) hand-operated valve of distributor to separate unit boiler is opened, ammonium hydroxide enters the spray gun of each boiler, sprays into boiler；
(5) according to ammonium hydroxide flow and concentration difference ammonium hydroxide and clear water flow, and the content of flue gas nitrogen oxide is combined to be adjusted,
Subject to emission compliance
Preferably: the adjusting in denitrating system operational process should be carried out according to the data of on-line monitoring, should in time, accurately adjust ammonia
Water avoids nitrogen oxides from fluctuating；
Preferably, boiler temperature control is at 960-980 DEG C；
Preferably, the control of horizontal flue temperature is at 800-840 DEG C；
Preferably, the dosage of ammonium hydroxide are as follows: 150-650kg/h；
Preferably, the dosage of desalted water are as follows: 100-650 kg/h.
SNCR is the flue gas preference temperature in burner hearth or recirculating fluidized bed separator in the case where not using catalyst
Place uniformly sprays into the amino reductives such as ammonia or urea, and reducing agent decomposes rapidly in furnace, and production N2 is reacted with the NOX in flue gas
And water, to achieve the purpose that denitration, SNCR reaction controlling is carried out in the very narrow corresponding burner hearth position of flue-gas temperature range.
The process flow of SNCR flue gas denitrification system are as follows: granular urea is sent into urea dissolving tank, and is dissolved in and removing in tank
In salt water, become the urea liquid of 40-50%, it is according to boiler operatiopn operating condition and DS NOx Est amount that urea is molten by on-line dilution system
Liquid is diluted to required concentration, spraying system is sent into after urea liquid is distributed and measured by metering distribution system, by spraying
It penetrates system and sprays into separator inlet flue, to drop low NOX emission.
In SNCR deamination technique, main chemical reaction are as follows:
(1) use ammonia or ammonium hydroxide as reducing agent: NH3+NOx → N2+H2O
(2) it is reducing agent with urea liquid:
CO(NH2)2→CO+2NH2
CO+NOx→N2+CO2
NH2+NOx→N2+H2O
(3) when the temperature is excessively high, ammonia is oxidized to NOx:
NH3+O2→NOx+H2O
There are many factors impacted to SNCR denitration efficiency, mainly has: under reaction temperature reducing agent type suitable temperature
Residence time reducing agent mixes with flue gas O2 and CO in the initial NOx concentration level flue gas of degree NH3/NOx molar ratio
Concentration etc. is generally acknowledged that the window temperature of SNCR denitration technology reaction is 800-1100 DEG C, if reaction temperature is too low, reaction rate
It can decrease, redox reaction cannot fully occur in time, cause denitration efficiency to reduce, while not participating in going back for reaction
Former agent enters rear portion equipment with flue gas, is ultimately discharged into atmosphere.But reaction temperature can not be excessively high, when temperature is higher than certain temperature
When, reducing agent can be aoxidized by the O2 in flue gas and generate NOx, and NOx concentration is caused to go up not down
Ammonia agent type is mainly three kinds of liquefied ammonia ammonium hydroxide urea, respectively has advantage and disadvantage injection liquefied ammonia to be easy to mix well with flue gas,
But the storage and use of liquefied ammonia all have certain risk, and a danger source injection urea is increased for enterprise more
Safety, and be readily transported and store, but when being sprayed, uniformity is relatively poor, influences reaction efficiency, amount of ammonia slip
Height is easy to generate highly viscous dust stratification, results in blockage to equipment and corrodes the advantage and disadvantage of injection ammonium hydroxide then between liquefied ammonia and urea
Between
Residence time refer to reducing agent spray into after to denitration reaction completion must be completed within this time total time it is following
Step: decomposition (as also with urea) reducing agent of the evaporation reducing agent of water mixes with flue gas reducing agent and the generation oxygen of NOx
Changing the reduction reaction residence time is the necessary condition for guaranteeing denitration efficiency, and residence time deficiency will result directly in denitration efficiency
Decline
The length of residence time depends on being proved with the sectional dimension of flue gas flow rate and flue gas circulation passage according to correlation test:
The flow rate effect reaction time of flue gas, excessively high flue gas flow rate can reduce the residence time, to reduce denitration efficiency;And cigarette
Although the too low denitration reaction that is conducive to of gas velocity sufficiently carries out, in boiler tail, the problems such as being easy to produce dust stratification of flue
So suitable flue gas flow rate is selected in the case where flue cross section product ought not be changed to control the residence time and be very important root
Show according to correlation test, the residence time, general warranty was between 0.7s-1.0s
The utility model has the advantages that
1, the NOx content in tail gas is monitored on-line using equipment advantage, and by realizing automation interlocked control NH3 spray
The amount of penetrating guarantees NOx and NH3 reaction density, it is ensured that tail gas qualified discharge；
2, the burner hearth reaction temperature for controlling NH3 and NOx, before both guaranteeing coal-fired full combustion thermal efficiency maximum utilizationization
It puts, in turn ensures that NH3 reacts optimum temperature with NOx, it is ensured that the optimization treatment effeciency of NOx；
3,150mg/Nm3 is reduced to by 350mg/Nm3 according to discharge capacity outside NOx in coal-fired boiler tail gas, then according to year production 120,000
Ton titanium dioxide calculates, then 206 tons/year of year emission reduction NOx.
Specific embodiment
The present invention is described in detail below.
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to embodiments, to the present invention
It is further elaborated.It should be appreciated that described herein, specific examples are only used to explain the present invention, is not used to limit
The fixed present invention.
A kind of method of CFB denitration:
(1) spray gun atomization compressed air hand-operated valve, gun inlets ammonia water pipeline hand-operated valve, ammonium hydroxide pump discharge hand-operated valve are opened and is returned
Flow valve, dilution water (desalted water) pump discharge valve and return valve；
(2) start aqua ammonia pump, adjust return valve and control its pressure in (0.4-0.6) MPa；
(3) starting dilution fresh water pump, adjusts return valve, controls its pressure in (0.4-0.6) MPa；It is according to ammonia concn control
10% is adjusted；
(4) hand-operated valve of distributor to separate unit boiler is opened, ammonium hydroxide enters the spray gun of each boiler, sprays into boiler；
(5) according to ammonium hydroxide flow and concentration difference ammonium hydroxide and clear water flow, and the content of flue gas nitrogen oxide is combined to be adjusted,
Subject to emission compliance
In the above process, boiler temperature is controlled at 978 DEG C；Horizontal flue temperature is controlled at 822 DEG C；The dosage of ammonium hydroxide are as follows:
166kg/h；The dosage of desalted water are as follows: 166 kg/h, it is 100mg/m3 that monitoring, which obtains amount of NOx, and original NOx content is
350mg/m3 reduces ratio 70%.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Made any modifications, equivalent replacements, and improvements etc., should all be included in the protection scope of the present invention within mind and principle.
Claims (6)
1. a kind of method of CFB boiler denitration, which comprises the following steps:
(1) spray gun atomization compressed air hand-operated valve, gun inlets ammonia water pipeline hand-operated valve, ammonium hydroxide pump discharge hand-operated valve are opened and is returned
Flow valve, dilution water (desalted water) pump discharge valve and return valve；
(2) start aqua ammonia pump, adjust return valve and control its pressure in (0.4-0.6) MPa；
(3) starting dilution fresh water pump, adjusts return valve, controls its pressure in (0.4-0.6) MPa；It is according to ammonia concn control
10% is adjusted；
(4) hand-operated valve of distributor to separate unit boiler is opened, ammonium hydroxide enters the spray gun of each boiler, sprays into boiler；
(5) according to ammonium hydroxide flow and concentration difference ammonium hydroxide and clear water flow, and the content of flue gas nitrogen oxide is combined to be adjusted,
To emission compliance.
2. a kind of method of CFB boiler denitration according to claim 1, it is characterised in that in denitrating system operational process
Adjusting should be carried out according to the data of on-line monitoring, should in time, accurately adjust ammonia vol, avoid nitrogen oxides from fluctuating.
3. a kind of method of CFB boiler denitration according to claim 1, it is characterised in that boiler temperature is controlled in 960-
980℃。
4. a kind of method of CFB boiler denitration according to claim 1, it is characterised in that the control of horizontal flue temperature exists
800-840℃。
5. a kind of method of CFB boiler denitration according to claim 1, it is characterised in that the dosage of ammonium hydroxide are as follows: 150-
650kg/h。
6. a kind of method of CFB boiler denitration according to claim 1, it is characterised in that the dosage of desalted water are as follows: 100-
650 kg/h。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811033540.4A CN109173665A (en) | 2018-09-05 | 2018-09-05 | A kind of method of CFB boiler denitration |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811033540.4A CN109173665A (en) | 2018-09-05 | 2018-09-05 | A kind of method of CFB boiler denitration |
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| Publication Number | Publication Date |
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| CN109173665A true CN109173665A (en) | 2019-01-11 |
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| CN201811033540.4A Pending CN109173665A (en) | 2018-09-05 | 2018-09-05 | A kind of method of CFB boiler denitration |
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102179171A (en) * | 2011-03-28 | 2011-09-14 | 浙江大学 | Multi-stage themolysis coupled denitration method using front flow field uniformizing device and device thereof |
| CN104001420A (en) * | 2014-06-09 | 2014-08-27 | 盐城工学院 | Flue gas SNCR (selective non-catalytic reduction) denitration control device and method |
| CN105169919A (en) * | 2015-10-09 | 2015-12-23 | 索通发展股份有限公司 | Flue gas denitration device for carbon pot calciner and denitration technology of flue gas denitration device |
| CN207361825U (en) * | 2017-09-30 | 2018-05-15 | 浦湘生物能源股份有限公司 | A kind of high-concentration ammonia nitrogenous wastewater cooperates with the system administered with flue gas of refuse burning NOx pollutants |
-
2018
- 2018-09-05 CN CN201811033540.4A patent/CN109173665A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102179171A (en) * | 2011-03-28 | 2011-09-14 | 浙江大学 | Multi-stage themolysis coupled denitration method using front flow field uniformizing device and device thereof |
| CN104001420A (en) * | 2014-06-09 | 2014-08-27 | 盐城工学院 | Flue gas SNCR (selective non-catalytic reduction) denitration control device and method |
| CN105169919A (en) * | 2015-10-09 | 2015-12-23 | 索通发展股份有限公司 | Flue gas denitration device for carbon pot calciner and denitration technology of flue gas denitration device |
| CN207361825U (en) * | 2017-09-30 | 2018-05-15 | 浦湘生物能源股份有限公司 | A kind of high-concentration ammonia nitrogenous wastewater cooperates with the system administered with flue gas of refuse burning NOx pollutants |
Non-Patent Citations (1)
| Title |
|---|
| 郑志侠主编: "《水泥行业污染物综合控制技术》", 30 July 2015, 中国环境出版社 * |
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| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 441500 No.1 Bianhe Road, Chengguan Town, Nanzhang County, Xiangyang City, Hubei Province Applicant after: Longbai Xiangyang Titanium Industry Co.,Ltd. Address before: 441500 No.1 Bianhe Road, Chengguan Town, Nanzhang County, Xiangyang City, Hubei Province Applicant before: XIANGYANG LOMON TITANIUM INDUSTRY Co.,Ltd. |
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| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190111 |
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| RJ01 | Rejection of invention patent application after publication |