CN104930525A - Method and for purifying exhaust gas - Google Patents

Method and for purifying exhaust gas Download PDF

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Publication number
CN104930525A
CN104930525A CN201410105933.7A CN201410105933A CN104930525A CN 104930525 A CN104930525 A CN 104930525A CN 201410105933 A CN201410105933 A CN 201410105933A CN 104930525 A CN104930525 A CN 104930525A
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regenerator
catalyst
combustion chamber
waste gas
purifying
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克里斯蒂安·穆勒德
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Chemisch Thermische Prozesstechnik GmbH
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Chemisch Thermische Prozesstechnik GmbH
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Priority to CN201410105933.7A priority Critical patent/CN104930525A/en
Publication of CN104930525A publication Critical patent/CN104930525A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/06—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases
    • F23G7/07—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals of waste gases or noxious gases, e.g. exhaust gases in which combustion takes place in the presence of catalytic material
    • 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
    • B01D53/38—Removing components of undefined structure
    • B01D53/44—Organic components
    • 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
    • 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
    • B01D53/62—Carbon oxides
    • 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
    • B01D53/86—Catalytic processes
    • B01D53/90—Injecting reactants
    • 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
    • B01D53/96—Regeneration, reactivation or recycling of reactants
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
    • Y02C20/00—Capture or disposal of greenhouse gases
    • Y02C20/10—Capture or disposal of greenhouse gases of nitrous oxide (N2O)
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/30—Improvements relating to adipic acid or caprolactam production

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Sustainable Development (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

In order to purify exhaust gas containing nitrogen oxide combined with CO, VOC or nitrous oxide, especially exhaust gas generated during the production of cement clinker, nitric acid, adipic acid, fertilizer and uranium trioxide, a regeneration-type post-heat burning system equipped with at least two regenerators (A, B) is employed and the CO, VOC and nitrous oxide are purified thermally in a combustor (1) under the temperature from 800 DEG C to 1000 DEG C through the system. The thermal recovery of oxynitride is achieved through the adding of a hydronitrogen SCR catalyst (6), wherein the purified exhaust gas is removed out at a proper position from the corresponding two regenerators (A, B) under the temperature of about 300 DEG C. and is guided in a fixed flowing direction through the hydronitrogen SCR catalyst (6) and then fed back to the remaining sections (A', B') of the two regenerators (A, B).

Description

For the method and apparatus of exhaust gas purification
Technical field
The present invention's preamble according to claim 1 relates to a kind of method.The invention still further relates to the purposes for the device and this device implementing the method.
Background technology
The combination of the hot afterburner combustion system of known regenerative and SCR (SCR) from DE19905733B4.In this approach, SCR catalyst material is disposed on recuperative heat exchanger material separately, thus when achieving the thorough catalysis denitrogenation with high thermal efficiency when regenerator entrance adds reducing agent.But this method does not allow Simultaneous purification organic component, because the temperature above catalyst is not enough to thermal oxide organic pollution.
The process of purifying exhaust gases of known a kind of preamble according to claim 1 from EP472605B1, wherein regenerator is vertically divided into three parts (Fig. 4).First, waste gas flows through the bottom low temperature section of regenerator, and then by the SCR catalyst at center, wherein ammonia is absorbed from waste gas.Subsequently, waste gas is heated to 800 DEG C at the upper pyrometer section of regenerator, and organic substance is burnt by heat in adjacent combustion chamber.Then the waste gas of prepurification flow through second high-temp regenerator in such a way, and by heat delivery to its heat storage.Subsequently, at the temperature of about 430 to 230 DEG C, nitrogen oxide (NO x) be reduced on catalyst layer with absorbed ammonia.
A shortcoming of the method is that it causes in the flowing direction, the Temperature Distribution height fluctuation above SCR catalyst, and as in a heat exchanger, it also still changes with circulation timei.For the reason that technique is relevant, can not operate on it throughout its whole volume under the optimum temperature of SCR catalyst.In addition, the permanent change of temperature means the high mechanical stress to SCR catalyst.
Further shortcoming is, if NO xbe reduced into nitrogen (N 2) then heat release.At high NO xwhen concentration, the heat of single release just limits maximum NO xentrance concentration, because if not SCR catalyst is aging by standing by the overheated Rapid Thermal caused.When the Temperature Distribution must considered equally in SCR catalyst length and fluctuation thereof, maximum NO xentrance concentration significantly reduces.
Further major defect is, in the already known processes with three regenerators, if use the material evenly extruded or the obvious more expensive ceramic honeycomb heat exchanger scribbling SCR-catalytically active coatings (washcoat) of corrugated SCR catalyst replacement be made up of the material of flexible relative, then for structural reason, each regenerator has at least three screens to be necessary.
In addition, the catalyst of sufficient amount must in each regenerator, be provided, therefore compared with single SCR system, when system has two regenerators, the quantity of catalyst will double, and when system has three regenerators, the quantity of catalyst wants three times.
Summary of the invention
Therefore on the one hand, the object of the invention is to utilize in regenerative thermal process from the thermal oxide of organic component and carbon monoxide (CO) or after-combustion and/or nitrous oxide (N 2o) thermal reduction becomes nitrogen (N 2) whole energy containing amount – if possible, without any need for external energy Gong Gei – mode be react by improving the temperature that produces, and use the latter to carry out denitrogenation by means of SCR, and on the other hand, when not needing under the optimum working temperature being provided in SCR catalyst when supplying separately energy throughout the possibility that its whole volume operates on it.
According to the present invention, this is that method realizes by being feature with claim 1.In claim 2 to 9, preferred embodiment of the process according to the invention is described.Relate to and being launched further by the measure of claim 11 to 14 according to the claim 10 of the preferred embodiment of the inventive method for implementing.Claim 15 relates to the preferable use according to device of the present invention.
According to the present invention, what in hot afterburner combustion system, purifying contained the oxidation of used atmosphere oxygen can the compound of hot purifying and nitrogen oxide and/or during hot purifying, form the waste gas of compound of nitrogen oxide.Oxidable can the compound (especially) of hot purifying be VOC (VOC), carbon monoxide, ammonia and nitrous oxide, wherein ammonia (NH 3) be reduced into nitrogen (N 2), NO xand water, and wherein nitrous oxide (N 2o) N is reduced into 2and O 2and be oxidized to NO x.Except nitrous oxide, during hot purifying, can thermosetting nitrogen oxide higher than (like in burner flame) at the temperature of 1100 DEG C or the organic compounds containing nitrogen (especially) by means of such as amine, nitrile or cyanide, therefore do not need to use catalyst.
Afterburner combustion system has at least two and is filled with heat storage and the regenerator being connected to common combustion chamber.Want the waste gas of purifying by the unstrpped gas entrance regenerator being alternately supplied to its heat storage and being preheated, and from combustion chamber, hot purification of exhaust gas out exports regenerator to clean air, reacts for the heating of its heat storage and nitrogen oxide and the nitrogen SCR by means of reducing agent.
No matter unstrpped gas temperature, in order to reach the temperature needed for SCR reaction, do not need to consume extra energy.
According to the present invention, at least two regenerators of afterburner combustion system are divided into two parts in the flowing direction separately, i.e. first section carrying combustion chamber of regenerator and second section towards combustion chamber of regenerator.Described at least two regenerators have common SCR catalyst, wherein in a combustion chamber hot purifying waste gas in clean air outlet regenerator the section adjacent with combustion chamber in cool after reach SCR react needed for the temperature of about 300 DEG C, and mix with reducing agent, be fed into common catalyst for the formation of clean air.
Its heat delivery is exported the heat storage carrying the second section of combustion chamber of regenerator to clean air by the unstrpped gas obtained by means of SCR catalyst, and is then directed into outside.
According to method of the present invention (there is the advantage by the constant flow of SCR catalyst at optimum catalyst temperature), also likely use the SCR catalyst extruded, such as, based on vanadic anhydride (V 2o 5), tungstic acid (WO 3) and/or titanium dioxide (TiO 2) catalyst, the resistance of these catalyst to mechanical stress and variations in temperature is very little, but on the other hand, these catalyst are more cheap.
No matter the quantity of regenerator, only can implement according to method of the present invention by a SCR catalyst, always it is in a same direction through-flow, not rely on the circulation of hot afterburner combustion system.
In order to reach the temperature needed for SCR reaction, SCR reaction does not need to consume extra energy, because the waste gas in clean air outlet regenerator can be moved out of at the section towards combustion chamber, thus is in suitable position.Select the position that this is suitable, the waste gas of purifying in the combustion chamber of preferred at least 800 DEG C of temperature is cooled by this way after the section adjacent with combustion chamber flowing through clean air outlet regenerator, be conditioned to make the temperature needed for SCR reaction, wherein this temperature is preferably 200 to 400 DEG C, particularly 250 to 350 DEG C, and be particularly preferably 280 to 320 DEG C.
In order to ensure the selective of SCR catalyst with reduce the aging of SCR catalyst to greatest extent, but also prevent SO 2be oxidized to SO 3, the operating temperature window so determined must be selected.
By reducing agent is supplied in combustion chamber, the nitrogen oxide in combustion chamber can heat means (not therefore being means of catalysis) by pre-denitrogenation, mode is by they are reduced into nitrogen.
For the nitrogen oxide in reduction combustion chamber, be preferably used as the nitrogen-hydrogen compound of the aqueous solution.Ammonia, urea or carbamic acid can such as be used as nitrogen-hydrogen compound.
In order to reduce the reaction temperature in combustion chamber needed for hot denitrogenation, additive can be added in nitrogen-hydrogen compound, the such as organic compound of such as alcohol.In order to the aqueous solution best distribution in a combustion chamber of nitrogen-hydrogen compound, two fluid tips or ultrasonic atomizer can be set, there is constant or pulsation pump precompression separately.
By supply reducing agent in combustion chamber, about 50% of the nitrogen oxide carrying capacity of usual unstrpped gas is removed; Hot NO in a combustion chamber xammonia effusion possible between reduction period is used as extra reducing agent by adjacent SCR catalyst, so according to the present invention, reduces while there is not emission intensity and reducing agent demand between the SCR stage of reaction.As reducing agent, the reducing agent containing VOC also can be made to get involved combustion chamber, such as, from the waste water of photograph industry or chemical industry, it also contains the organic solvent of a great deal of except ammonia.
For SCR reaction, using the aqueous solution or in a gaseous form via single-stage or double-stage hybrid device the nitrogen-hydrogen compound (such as ammonia) as reducing agent is supplied to clean air outlet regenerator direct in the upstream of SCR catalyst towards the second section of combustion chamber.
The heat storage of the hot afterburner combustion system of regenerative is preferably made up of the prismatic ceramic heat storage body extruded, and this prismatic ceramic heat storage body extruded has multiple gas flow path passage extended in the direction of the air flow, such as, described in EP472605B1.SCR catalyst also can by make with SCR catalyst material and this prismatic ceramic heat storage body extruded with the gas flow path passage extended in the direction of the air flow is formed.
Before mixing with reducing agent, the waste gas of hot purifying preferably flows through ceramic bed in bulk, and object is in order to its temperature of homogenizing before waste gas enters SCR catalyst.Ceramic filling material is made up of the ceramic mouldings being preferably saddle type or annular.Its reducing agent added that distributes in the cross section of SCR catalyst, and the same temperature fluctuation reducing SCR catalyst porch.
According to the present invention, waste gas is so in the circulating cycle by the unstrpped gas entrance regenerator being alternately supplied at least one its heat storage and being preheated.The waste gas of purifying is fed into combustion chamber in such a way, and described combustion chamber has the high temperature more than 800 DEG C, particularly 850 to 1000 DEG C.At these elevated temperatures, VOC is burnt by the aerial oxygen in waste gas, and/or nitrous oxide is thermally transformed by the reproducing beam into nitrogen.When flowing through the section towards combustion chamber of clean air outlet regenerator, the heat produced is transported to this section.By from two parts clean air outlet regenerator towards combustion gas in the section of combustion chamber, likely in all circulations, guide waste gas via SCR catalyst in a same direction.After flow distribution and temperature homogenisation, supply the waste gas that mixes with reducing agent in the circulating cycle by ceramic bed in bulk to the SCR catalyst under the optimum working temperature of about 300 DEG C.Clean air, (and) waste gas that is therefore also purified by means of SCR catalyst by the section of carrying combustion chamber of remaining heat delivery to two parts clean air outlet regenerator, make to react by SCR the heat produced and also can be utilized.
If implement thermal reduction without reducing agent, such as, at the temperature of 800 to 850 DEG C, the waste gas time of staying is in a combustion chamber preferably 0.5 to 3 second, particularly 0.7 to 1.5 second.Comparatively speaking, when using reducing agent to carry out hot SNCR reduction, under the chamber temperature more than 850 DEG C, particularly 900 to 950 DEG C, the time of staying is preferably 1 to 4 second, particularly 1.5 to 2 seconds.When nitrous oxide is thermal decomposited, under the chamber temperature of preferably 900 to 1000 DEG C, particularly 950 to 970 DEG C, the time of staying is preferably 1 to 3 second, particularly 1.5 to 2 seconds.
In order to remove the residual gas contained in unstrpped gas entrance regenerator, preferably before the direction of waste gas streams changes, use the clean air from other two parts regenerator that each unstrpped gas entrance regenerator is purged a circulation.About VOC or carbon monoxide, the purification efficiency being greater than 99.5% can be realized.
When higher exhaust flow speed, provide multiple regenerators constructed according to the invention to replacing two or three regenerators.This makes likely the size of single regenerator to be limited in transportable scale.In addition, the alternately thermal stress load of SCR catalyst is reduced by the order route of regenerator.Compared with having the system of three regenerators, the alternately load of SCR catalyst is such as only 50% of the system situation with five regenerators, and is only 33% of the system situation with seven regenerators.
In the device for implementing according to method of the present invention, at least two regenerators being connected to co-fire room are preferably arranged to parallel to each other.They have two separately, and to be preferably arranged in the vertical direction stacked on top of each other and be filled with the section of heat storage.Fixture (mounting) side direction had at least two regenerators are common SCR catalyst is attached to described section.
For catalyst being connected to lower curtate and the upper curtate of at least two regenerators, fixture has stop valve, is preferably poppet valve, their arrangement make stream by or walk around (namely not passing through) SCR catalyst.
The present invention is applicable to the waste gas that can form the compound of nitrogen oxide during the compound of hot purifying and nitrogen oxide and/or the hot purifying in the combustion chamber of hot afterburner combustion system that purifying contains aerial oxygen oxidation in available waste gas usually.
Therefore, purifying is specially adapted to by the waste gas produced clinker, nitric acid, adipic acid and fertilizer and produce according to method of the present invention and device according to the present invention.In addition, be applicable to purifying by the waste gas produced orange oxide and produce according to method of the present invention and/or device according to the present invention, described orange oxide obtains by heating ammonium diuranate (uranium concentrate) in oxygen atmosphere.
About having the device that five are with the regenerator purging options, the circular order route of the stop valve of regenerator (namely illustrate route map) is described in following table by way of example, wherein the numbering of stop valve and Fig. 3 of accompanying drawing corresponding, and regenerator is correspondingly expressed as A to E." 0 " represents the stop valve of closing, and " 1 " represents the stop valve opened.
Embodiment 1
(production clinker)
Producing clinker is a kind of power consumption (energy-intensive) process, and why Here it is is used for preheated raw meal by the waste gas streams of rotary kiln, to utilize used heat as much as possible during described process.In modern cement plant, also utilize the used heat of clinker cooler.However, about 100.000Nm 3the waste air flow of/h has the temperature of 130 to 200 DEG C, which reflects the demand of the heat energy to cement plant, and Here it is why secondary fuel and the soil that excavates with high hydrocarbon content will be processed together with raw material.Due to evaporation and partial thermal decomposition, the carbon monoxide of hydrocarbon (VOC) and formation in addition and NO xcan not find the mode that they enter the hot rotary kiln with reverse waste gas streams, but major part is directly transported in waste gas.System according to the present invention guarantees pollutant that is reliable and this wide scope of purifying efficiently, and makes it possible in quality and quantitatively use relatively large secondary raw material and secondary fuel, and does not have any negative effect to environment.
The waste gas of the clinker kiln in interconnected operation
Volume flow 200.000Nm 3/ h
Temperature 150 DEG C
VOC600mg/Nm 3dry, based on 10%O2
CO5000mg/Nm 3dry, based on 10%O2
NO x800mg/Nm 3dry, based on 10%O2
Dust 2 – 5mg/Nm 3, after fabric filtration
Adopt according to system of the present invention (the covert form of 5-bed), the energy content of waste gas is utilized with the form of pollutant, so as in autothermal operation purifying VOC, CO and NO x.
For this purpose, recuperative heat exchanger is used to by heating by the exhaust gases to temperature >800 DEG C, consequently discharges enough energy by the oxidation of CO and VOC, to maintain this temperature.
The purifying of CO and TOC is 99.5%.
The waste gas of downstream (entrance SCR catalyst) side of combustion chamber
Temperature 320 DEG C
CO25mg/Nm 3
TOC3mg/Nm 3
NO X820mg/Nm 3
The waste gas through cleaning of downstream (chimney) side of SCR catalyst
Temperature 200 DEG C
CO30mg/Nm 3
TOC5mg/Nm 3
NO X150mg/Nm 3
NH35mg/Nm 3
Reducing agent is 65kg/h NH at the consumption in SCR stage 3(100%).Its so low reason is, the NO of existence 2become NO by method thermal transition according to the present invention equally, and the waste gas short time is heated to the temperature (NO of >800 DEG C relatively xbalance on NO side), be then cool rapidly on an equal basis.
Therefore, also can be observed economically for this application according to the standard limited value of TA Luft (technological guidance of air quality control).
Embodiment 2
(production ammonia)
For the chemicals producing fertilizer and such as ammonium nitrate, caprolactam, adipic acid, dinitrotoluene (DNT) and nitrobenzene, bringing into use the nitric acid produced by ammonia.Greenhouse gases nitrous oxide (N is discharged as accessory substance 2o), it has up to CO 2the global warming up trend of 320 times, although therefore investment and running cost height also regularly to carry out catalytic purification, because due to CO 2the reason of licensing, also likely partly compensates these costs at present.
Method according to the present invention makes it possible to remove nitrous oxide, VOC and NO with remarkable lower cost simultaneously x.
In order to produce the ammonium nitrate of 560 tons/day, need the ammonia of 7700kg/h.70.000Nm 3the corresponding tail gas of/h contains 3g/Nm 3n 2o.If use catalyst to carry out purifying N 2o, then due to the reason (1 to 3 production cycle) of catalyst rapid contamination, purification efficiency is starkly lower than 90%, and totle drilling cost is significantly higher.
Adopt according to system of the present invention, nitrous oxide is thermal decomposited into N 2(purifying of >95%).By <14 % by mole of N 2the nitrogen oxide that the side reaction of O produces and the SCR reactor by means of entirety and being included in together with the nitrogen oxide in waste gas is purified, and waste gas is without the need to by heating second time.For this reason, compared with the covert form of pure catalysis, running cost can be reduced to the amount of below half.
Meanwhile, adopt according to method of the present invention, environmental pollution (VOC and NO x) reduce by 95% (being only the half discharge of the pure covert form of catalysis).In addition, nitrogen oxide is reduced, and the discharge of methane that described method may exist obtains purifying and use in energy.
By make SCR and hot SNCR, (and) on-catalytic denitrogenation therefore combines, and can reach high purification efficiency.The twice that reducing agent consumption due to thermal reduction is approximately SCR situation is high, if therefore SCR catalyst is fresh, then SCR catalyst can be mainly used in NO xreduction.In SCR catalyst aging or part pollute, in order to keep clean air concentration low and stable, hot denitrogenation can be adopted in addition.
Detailed description of the invention
According to Fig. 1, the hot after-burner of regenerative has two are connected to burner 2 or electric heater unit regenerator A and B by means of co-fire room 1.Temperature is that in the combustion chamber 1 of such as 900 DEG C, waste gas is by hot purifying wherein.
Regenerator A and B is divided into two parts in the flowing direction separately.That is their each freedom are carried the lower curtate A ' of combustion chamber 1 and B ' respectively and are formed towards the upper curtate A ' ' of combustion chamber 1 and B ' ' respectively.Section A ', A ' ', B ' and B ' ' are filled with heat storage 3 separately.
Two section A ', A ' ' and B ', the B ' ' of each regenerator A and B are connected to each other by means of pipeline 4 and 5 respectively, are eachly provided with stop valve V-5A and V-5B.
Two regenerator A and B have common SCR catalyst 6.
For this purpose, upper curtate A ' ' is connected to pipeline 7 in their lower end via stop valve V-6A and V-6B with B ' ', and lower curtate A ' and B ' is connected to pipeline 8 in their upper end via stop valve V-4A and V-5B.
Supply the waste gas of hot purifying in combustion chamber 1 respectively via upper pipeline 7 according to the switching of stop valve V-6A and V-6B, upper pipeline 7 is connected to the room 9 with the grid being such as with nozzle 11, nozzle 11, for supplying the nitrogen-hydrogen compound as reducing agent, reduces for adopting the SCR of catalyst 6.
Nozzle 11 is arranged in the room 9 of blender 12 upstream of such as deflection plate form.Pipeline 13 extends to the upper end of the room 14 wherein arranging SCR catalyst 6 from blender 12.
Extending into the ceramic filling material 15 arranging between the position of 14 and catalyst 6 and be made up of such as saddle at pipeline 13, its objective is the temperature entering the waste gas of catalyst 6 for mixing reducing agent and the waste gas of hot purifying in combustion chamber 1 and homogenizing extraly.
To be respectively supplied to the lower curtate A ' of regenerator A and B and the upper end of B ' that are switched to " clean air outlet " pattern from room 14 via pipeline 8 by the clean air that produces after SCR catalyst 6.
Unstrpped gas is supplied via unstrpped gas pipeline 17 by fan 16, and two regenerator A and B are connected to unstrpped gas pipeline 17 by means of stop valve V-1A and V-1B, namely respectively in the lower end of lower curtate A ' and B '.
Clean air is discharged into outside via clean air pipeline 18 and chimney 19.For this purpose, clean air pipeline is connected to the lower curtate A ' of two reactor A and B and the lower end of B ' by means of stop valve V-2A and V-2B.
In combustion chamber 1, nozzle 20,21 are separately positioned on above two regenerator A and B, wherein said nozzle supply nitrogen-hydrogen compound as reducing agent so that at least in part by pre-for the nitrogen oxide in combustion chamber denitrogenation, namely with heat but be not that the mode of catalysis is carried out.
Start the nozzle be arranged in above unstrpped gas tower or nozzle sets in each case, to maximize the time of staying of non-catalytic reduction.
Regenerator A and B is alternately operated, namely as unstrpped gas entrance regenerator operation or as clean air outlet regenerator operation, the former heat storage 3 is preheated, so that heating enters the unstrpped gas of combustion chamber 1, and clean air from the latter out, the heat storage simultaneously its heat being transported to respectively regenerator A and B is used for next circulation.
That is, when regenerator A forms unstrpped gas entrance regenerator and regenerator B forms clean air outlet regenerator, stop valve V-1A and stop valve V-2B is opened, and stop valve V-2A and V-1B is closed.In addition, the stop valve V-5A connecting two section A ' and A ' ' of regenerator A via pipeline 4 is opened, and stop valve V-4A and V-6A regenerator A being connected to SCR catalyst 6 is closed.
Be to be formed in this circulation in the regenerator B of clean air outlet regenerator, the stop valve V-5B connecting two section B ' ' and B ' via pipeline 5 is in this case closed, and stop valve V-6B and V-4B is opened, make after its partial heat is transported to the heat storage 3 of section B ' ' and after adding nitrogen-hydrogen compound by means of nozzle 11, from section B ' ' out and mixed in static mixer 12 and 15 respectively by the waste gas of hot prepurification and heating combustion chamber 1, and used the SCR reaction purification of catalyst 6, lower curtate B ' is entered via pipeline 8, so that by the heat storage 3 in its heat heating lower curtate B '.
Relative to the height of lower curtate B ', select the height of the upper curtate B ' ' of regenerator B, the temperature that the waste gas being supplied to catalyst 6 from section B ' ' is had is such as 250 to 350 DEG C, particularly 280 to 320 DEG C, and this is best to SCR reaction.
In a word, select the total height of regenerator, make clean air such as to pass into unstrpped gas pipeline 18 than the temperature of high 30 to 60 DEG C of unstrpped gas temperature and by chimney 19 directed outwards.Identical situation is applicable to the section A ' of regenerator A and the height of A ' ' and is applicable to all other parallel regeneration devices.
When forming unstrpped gas entrance regenerator at next cycle period regenerator B and regenerator A forms clean air outlet regenerator, valve V-1A, V-2B, V-5A, V-6B and V-4B are closed, and valve V-2A, V-4A, V-6A and V-5B are opened.
In Fig. 2 a and Fig. 2 b, (Fig. 2 a) exports regenerator (Fig. 2 b) with clean air to be shown as unstrpped gas entrance regenerator respectively according to the regenerator A of Fig. 1.In fig. 2 a, the unstrpped gas entered is illustrated by arrow P 1, and unstrpped gas is out indicated by the arrow P 2 in Fig. 2 b.
Can see from Fig. 2 a and 2b, catalyst 6, packing material 15, for supplying the nozzle 11 of nitrogen-hydrogen compound and being arranged in the fixture 22 in regenerator A side direction with stop valve V-4A, V-5A and V-6A of poppet valve formal construction.
Stop valve V-1A and V-2A respectively on unstrpped gas pipeline 17 and clean air pipeline 18 is configured to the form of poppet valve equally.
Second regenerator B (Fig. 1) is arranged in after regenerator A, therefore can't see in Fig. 2 a and 2b.This layout is also applicable to the regenerator existed in addition.
Comparison diagram 1, the lower curtate A ' of regenerator A and the lower curtate B ' that can't see in Fig. 2 a and 2b has the pipeline 23 of band stop valve V-3A separately in their lower end, for taking out remaining unstrpped gas, remaining unstrpped gas is moved out from above by the cleaning exhaust gas from combustion chamber, and feeds back to unstrpped gas as the tributary of about 5 to 10% subsequently.Before at every turn after regenerator being used as unstrpped gas entrance regenerator with used as clean air regenerator, it is purged.
According to Fig. 2 a and 2b, between two section A ' and A ' ', regenerator A has makes the deflection of the waste gas streams between section A ' and A ' ' enter the such deflection plate of fixture 22 or deflecting element 24.
It is common upper collection pipeline 25 and common collective low pipeline 26 that fixture 22 has two regenerator A and B, the former is used for the waste gas of purifying hot in combustion chamber 1 to be supplied to catalyst 6 from upper curtate A ' ' and B ' ' respectively, the latter is used for the clean air of catalyst 6 purifying, and it is supplied to respective lower curtate A ' and the B ' of regenerator A and B respectively.
Upper pipeline 25 in fixture 22 and be provided as the independent space 27 of each regenerator A, B between lower pipeline 26, the unstrpped gas of corresponding regenerator A, B and clean air flow into wherein, and catalyst 6 is spaced from by means of wall 28.
When regenerator A (or B) forms unstrpped gas entrance regenerator according to Fig. 2 a, the poppet valve V-5A (and the poppet valve V-5B of the regenerator B correspondingly do not shown in Fig. 2 a and 2b) of regenerator A is opened, and poppet valve V-6A and V-4A (and correspondingly V-6B and V-4B) closes collection conduit 25 and 26.
But, when regenerator A (or B) forms clean air outlet regenerator, according to Fig. 2 b, poppet valve V-4A and V-6A (and poppet valve V-4B and V-6B of regenerator B) of regenerator A is opened, and poppet valve V-5A (and correspondingly V-5B) is closed.
Have five regenerator A to E according to the device of Fig. 3, they are all construct by the mode identical with regenerator A with B according to Fig. 1 and Fig. 2 a with 2b.That is, preferred in the vertical direction all regenerator A to E disposed adjacent one another have the section A ' being filled with heat storage 3, A ' ', B ', B ' ' ... and common combustion chamber 1 and common catalyst 6.
Preferably, catalyst 6 is disposed in the sidepiece fixture being attached according to Fig. 2 a and 2b side direction and constructing.
The section A ' of each regenerator A to E, A ' ', B ', B ' ' ... can be connected to each other by means of stop valve V-5A to V-5E.Section A ', A ' ', B ', B ' ' ... can be connected to each other via the catalyst 6 in fixture 22 by means of stop valve V-6A to V-6E and V-4A to V-4E.
Schematically Fig. 3 is shown according to the upper collection pipeline 25 of Fig. 2 a and 2b and collective low pipeline 26.
In each case, a pair of regenerator A to E is switched to " unstrpped gas entrance " pattern, by another of regenerator A to E to being switched to " clean air outlet " pattern, and the 5th regenerator A to E is provided for purging.
For this purpose, by the lower curtate A ' of regenerator A to E with them, B ' ... lower end be connected to V-3E to purge pipeline 26 via stop valve V-3A (see Fig. 2 a and 2b), the unstrpped gas of evicting from from regenerator A to E is supplied to the unstrpped gas pipeline 17 of fan 16 upstream together with the clean air of the purifying from combustion chamber 1.
In the table of description, the cycling figure of the device according to Fig. 3 with five regenerator A to E is illustrated above.
Accompanying drawing explanation
Below with reference to accompanying drawings, in more detail the present invention is described by way of example, wherein:
Fig. 1 display is with the schematic diagram of the exhaust gas purification device of two reactors;
Fig. 2 a and 2b schematically shows the cross section exporting the regenerator of regenerator respectively as unstrpped gas entrance regenerator and clean air separately; And
Fig. 3 display is with the schematic diagram of the exhaust gas purification device of five makers.

Claims (17)

1. the method for a purification of exhaust gas, the compound that can form nitrogen oxide during the compound of hot purifying and nitrogen oxide and/or the hot purifying in afterburner combustion system that the described waste gas oxygen contained in available described waste gas carries out being oxidized, described afterburner combustion system has at least two and is filled with heat storage (3) and the regenerator (A being connected to common combustion chamber (1), B ... .), wherein described waste gas is alternately supplied to unstrpped gas entrance regenerator (A or B), its heat storage (3) is preheated, and be fed into clean air outlet regenerator (B or A) from described combustion chamber (1) hot purification of exhaust gas out, optionally nitrogen is catalysed and reduced into by means of reducing agent for the heating of its heat storage (3) and described nitrogen oxide, it is characterized in that, at least two regenerator (A, B ...) be divided into two parts separately in the flowing direction, namely described regenerator (A ', A ' ', B ', B ' ') carry described combustion chamber (1) and the section towards described combustion chamber (1), and described at least two regenerator (A, B ... ..) there is the co-catalysis agent (6) for described SCR, wherein the described clean air adjacent with described combustion chamber (1) is being cooled to export regenerator (A, B ...) section (A ' ', B ' ') in the temperature needed for SCR and after mixing with described reducing agent, in described combustion chamber (1), the waste gas of hot purifying is fed into described common catalyst (6), for the formation of clean air, heat delivery is exported regenerator (A to the described clean air carrying described combustion chamber (1) at it by described clean air, B ...) section (A ', B ') heat storage (3) after be directed into outside.
2. method according to claim 1, it is characterized in that, the waste gas of purifying contain as oxidable can the VOC of compound of hot purifying, carbon monoxide, ammonia and/or nitrous oxide and as forming the ammonia of the compound of nitrogen oxide, nitrous oxide and/or nitrogenous VOC during described hot purifying.
3. method according to claim 1, is characterized in that, the temperature needed for described SCR is 200 to 400 DEG C.
4., according to the method one of aforementioned claim Suo Shu, it is characterized in that, can by reducing agent being fed to the pre-denitrogenation of nitrogen oxide heat that is that make existence in the middle of described combustion chamber (1) or that formed in described combustion chamber (1).
5. according to the method one of aforementioned claim Suo Shu, it is characterized in that, the temperature in combustion chamber (1) is at least 800 DEG C, and is at least 900 DEG C when hot denitrogenation.
6. according to the method one of aforementioned claim Suo Shu, it is characterized in that, after mixing with described reducing agent, the waste gas of described hot purifying preferably flows through ceramic filling material (15), for entering its temperature of described catalyst (6) front homogenizing at described waste gas.
7. according to the method one of aforementioned claim Suo Shu, it is characterized in that, nitrogen-hydrogen compound is used for the reduction of nitrogen oxide in described combustion chamber (1) and/or utilizes catalyst (6) to be reduced into nitrogen.
8. according to the method one of aforementioned claim Suo Shu, it is characterized in that, the time of staying of described waste gas in described combustion chamber (1) is 0.3 to 1 second, and is 1 to 4 second when hot denitrogenation.
9. according to the method one of aforementioned claim Suo Shu, it is characterized in that, other regenerator (A to E) is set for flow to described clean air outlet regenerator at clean air before, purges described unstrpped gas entrance regenerator (A to E) with it.
10. for implementing the device according to the method one of aforementioned claim Suo Shu, it is characterized in that afterburner combustion system has the regenerator (A of co-fire room (1) with at least two, B), they have separately be arranged to stacked on top of each other and be filled with heat storage (3) two sections (A ', A ' '; B ', B ' '), and be attached to it with common fixture (22) side direction of the catalyst (6) for SCR, wherein said fixture (22) have for described catalyst (6) is connected to described lower curtate (A ', B ') and the stop valve (V-4A of described upper curtate (A ' ' and B ' '), V-5A, V-6A; V-4B, V-5B, V-6B), be wherein with or without the flowing by described catalyst (6).
11. devices according to claim 10, it is characterized in that, described fixture (22) has described at least two regenerator (A, B) for common upper collection pipeline (25) with to described at least two regenerator (A, B) be common collective low pipeline (26), the former is for being supplied to described catalyst (6) by the waste gas of described hot purifying, the latter is used for the clean air of described catalyst (6) purifying, space (27) is arranged in each regenerator (A, B) between described upper pipeline (25) and described lower pipeline (26), wherein said stop valve (V-4A, V-5A, V-6A) (V-4B, V-5B, V-6B) for described upper collection pipeline (25) is connected to described collective low pipeline (26) via described catalyst (6), or for by described regenerator (A, lower curtate B) (A ', B ') via described space (27) be connected thereto section (A ' ', B ' ').
12. devices according to claim 11, is characterized in that, are arranged in described upper collection pipeline (25) for the nozzle (11) for adopting the SCR of described catalyst (6) to supply described reducing agent.
13., according to claim 10 to the device one of 12 described, is characterized in that, described catalyst (6) arranges ceramic filling material (15), for waste gas described in homogenizing temperature and the latter is mixed with described reducing agent.
14. according to claim 10 to the device one of 13 described, it is characterized in that, multipair regenerator (A to E) is set, they have separately be arranged to stacked on top of each other and be filled with heat storage (3) two sections (A ', A ' ', B ', B ' '), and be attached to it with common fixture (22) side direction of the catalyst (6) for SCR, wherein said fixture (22) comprise for via described catalyst (6) described upper collection pipeline (25) is connected to described collective low pipeline (26) or by the described lower curtate of described regenerator (A to E) (A ', B ') be connected to described upper curtate (A ' ', B ' ', ) stop valve (V-4A to V-4E, V-5A to V-5E, V-6A to V-6E).
15. according to claim 10 to one of 14 the purposes of device, for purifying by the waste gas produced clinker, nitric acid, adipic acid, fertilizer and orange oxide and produce.
The method of 16. 1 kinds of purification of exhaust gas, described method comprises any combination of arbitrary technical characteristic in claim 1-10 or technical characteristic.
17. for implementing the device according to the method one of claim 1-10 Suo Shu, and described device comprises any combination of arbitrary technical characteristic in claim 11-15 or technical characteristic.
CN201410105933.7A 2014-03-20 2014-03-20 Method and for purifying exhaust gas Pending CN104930525A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106642165A (en) * 2017-01-23 2017-05-10 中石化炼化工程（集团）股份有限公司 Processing method for volatile organic compounds of refinery plant
CN108057343A (en) * 2016-11-07 2018-05-22 浙江奇彩环境科技股份有限公司 A kind of heat accumulating type selective reduction denitration device and denitrating technique
CN109028108A (en) * 2017-01-26 2018-12-18 化学热处理技术股份有限公司 Technique and device for waste gas purification
CN110538570A (en) * 2019-09-30 2019-12-06 河南神马尼龙化工有限责任公司 System and method for co-processing N2O and VOC in waste gas in caprolactam production

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108057343A (en) * 2016-11-07 2018-05-22 浙江奇彩环境科技股份有限公司 A kind of heat accumulating type selective reduction denitration device and denitrating technique
CN106642165A (en) * 2017-01-23 2017-05-10 中石化炼化工程（集团）股份有限公司 Processing method for volatile organic compounds of refinery plant
CN109028108A (en) * 2017-01-26 2018-12-18 化学热处理技术股份有限公司 Technique and device for waste gas purification
CN110538570A (en) * 2019-09-30 2019-12-06 河南神马尼龙化工有限责任公司 System and method for co-processing N2O and VOC in waste gas in caprolactam production
CN110538570B (en) * 2019-09-30 2024-03-22 河南神马尼龙化工有限责任公司 N in caprolactam production waste gas 2 O and VOC co-processing system and method

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