CN102671688A - Ozone decomposition composite catalyst and preparation method thereof - Google Patents
Ozone decomposition composite catalyst and preparation method thereof Download PDFInfo
- Publication number
- CN102671688A CN102671688A CN2012101431369A CN201210143136A CN102671688A CN 102671688 A CN102671688 A CN 102671688A CN 2012101431369 A CN2012101431369 A CN 2012101431369A CN 201210143136 A CN201210143136 A CN 201210143136A CN 102671688 A CN102671688 A CN 102671688A
- Authority
- CN
- China
- Prior art keywords
- quartz sand
- zeolite
- composite catalyst
- preparation
- iron
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
Landscapes
- Catalysts (AREA)
Abstract
The invention discloses an ozone decomposition composite catalyst and a preparation method thereof. The composite catalyst is prepared by mixing iron modified zeolite and iron modified quartz sand in a mass ratio of 1:4-4:1. The preparation method of the composite catalyst comprises the following steps: modifying zeolite with nano hydroxyl iron oxide to prepare iron modified zeolite, modifying quartz sand with iron ions in an alkalifying mode to prepare the iron modified quartz sand, and proportionally mixing the modified zeolite and the modified quartz sand to obtain the composite catalyst disclosed by the invention. The composite catalyst not only can display the heating of quartz sand to enhance the thermal decomposition action on O3, but also can display the adsorptive decomposition effect of the modified zeolite, and thus, has the advantages of high decomposition rate, high safety, no self consumption, long service life, no harmful substance generation and the like.
Description
Technical field
The present invention relates to the ozone decomposition catalyst technical field, particularly a kind of ozone decomposes composite catalyst and preparation method thereof.
Background technology
Ozone (O
3) significant to life on earth, ozone layer can absorb the ultraviolet ray below the sunlight medium wavelength 306.3nm, is umbrella human and that life on earth is depended on for existence, protects it to exempt from the intensive ultraviolet injury.Yet near-earth O
3Pollute and indoor O
3But can produce serious harm to the human body and the ecosystem.Research shows, works as O
3When concentration surpasses 0.05ppm, health is worked the mischief, when surpassing 0.1ppm, directly breathing and the motion function to human body impacts.O
3Can cause people's neurotoxic, dizziness headache, eyesight descend, are losing one's memory.Indoor O
3The chemical reaction that takes place with different organic substances and product be complicacy very, and product comprises carcinogen such as formaldehyde, methacrylaldehyde etc., pungent such as carbonyl, dicarbapentaborane, acids etc., and free radical, the organic aerosol of secondary etc.Excessive concentrations near-earth O
3There is toxic action in the plant growth, influences its growth and crop yield.O
3Be to have corrosive gas, can quicken the degraded and the aged deterioration of multiple macromolecular material, multiple metal and inorganic material are also had strong corrosiveness, the estimated amount of damage that causes the thus whole world reaches multi-million dollar every year.This shows O
3Influence to environment is so big.Therefore, near-earth and indoor O
3The harm that is caused must cause people's great attention.
Abroad for O
3Healthy mechanism research and control technology research start from the eighties in last century; Except having made up perfect monitor network; Importantly work out corresponding electric equipment products monitoring standard, wherein in the UL867 standard (electrostatic air cleaner), stipulated the O of air purifier specially
3Concentration control detection method.The NIKKI of Japan and the ingelhard company of the U.S. are the companies that produces catalyst specially, at O
3Have multinomial patent and company standard in the catalytic purification filter product.The airmpro radiator coating of the VOlVO motor corporation exploitation of Sweden is specifically designed to environment O
3Eliminate.The International Olympic Committee also contrasts the O of Games-time
3Concentration has been carried out clear and definite regulation, as environment O
3When concentration was higher than 0.080ppm, most strenuous exercises athletics event must not be held.NAS and national project institute have also set up special mechanism for this reason, strengthen O
3The research of pollution problem.
Domestic for near-earth O
3With indoor O
3The research of polluting is started late, but in recent years along with to O
3The attention of contamination hazard is specifically designed to low concentration O
3The product of catalytic purification increases day by day, for example is used for the O of electrostatic air cleaner
3Filter, the O on duplicator, the laser printer
3Filter, central air-conditioning VMC O
3Products such as filter increase gradually, and still, domestic still do not have this series products core component a---O
3The examination criteria of filter.Domestic examination criteria that at present can reference is UL867 " electrostatic air cleaner ", but the complete machine that only is suitable for electrostatic air cleaner detects.
The control approach of current ozone pollution and the problem of existence:
Present main O
3Decomposition method has dilution method, washing method (soup absorption process), thermal decomposition method, electromagenetic wave radiation decomposition method, active carbon adsorption, catalytic decomposition method etc.
Dilution method contains O with the dilution of the fresh air in the ventilating system
3Tail gas.But directly reach discharging tail gas 1.46 * 10
-9MolL
-1O
3The required thinner ratio of Security Target is very high.So this method is only at residue O
3Further utilize, guarantee suitable atmospheric dilution, connect the exhaust chimney and be only practicable afterwards such as 8～10.Advantage is that operating cost is low, and equipment is simple; Subject matter is that noise is excessive, and effect is general.
Washing method.Water washs tail gas in spray column, removes O wherein
3Shortcoming is that equipment is huge, and effect is general.
Thermal decomposition method.O
3More stable in air than in water, O under the room temperature
34～16hr does not wait in the half-life of gas phase.O in the air
3Thermal decomposition promptly begin as far back as 30 ℃, remarkable in the time of 40～50 ℃.O in 200 ℃ of next minutes
3Decompose when approximately being 70%, 230 ℃ 92%～95%.At 270 ℃ or when above, 1～2s reaches 100% and decomposes in the reaction time.Therefore thermal decomposition method is the current contained O of tail gas that is used to eliminate
3Most popular technology, main technique have the single channel resistance heated, heat, heat and three kinds of modes of overheated burning through heat exchange.But current thermal decomposition method needs energy to supply with, and equipment is more complicated also.
Active carbon adsorption.Destroy O on the combustible support through being adsorbed on
3, be actually O
3Through the up flow type filter of active carbon filtering layer is housed, when burning consumes carbon at a slow speed, O
3Obtain decomposing.Absorption/decomposition is to utilize silica gel, molecular sieve to O
3Absorption set characteristic, make O
3Decompose, but after several times regeneration, the O of adsorbent
3Decomposability is lowered.Though active carbon has the ability of strong adsorption, catalytic decomposition, research shows O
3Part mechanism is presented as that activated carbon surface and constituent are oxidized in the decomposable process, and the essence of reaction is O
3To the smoulder process of active carbon, its life-span and validity are difficult to guarantee, can produce multiple accessory substance simultaneously
The catalytic decomposition method.Present most of catalyst all is palladium, manganese and nickel metal oxide, sometimes catalyst cupport on carrier, catalyst based like supported palladium on alumina particles.O
3Catalytic decomposition can make O
3Decompose sooner than with active carbon the time, but also exist catalyst to poison easily, service time is short, price is high, production process produces problems such as pollution.
Find that through analyzing these above-mentioned methods respectively have pluses and minuses at present, wherein the catalytic decomposition method is for O
3The decomposition effect best, so whether we can find a kind of better decomposition O through further research
3Catalyst?
Suitable catalyst should be a kind of existing extremely strong adsorption capacity, can enrichment O
3, strong catalytic decomposition O is arranged again
3Ability, and homeostasis is difficult for the material of loss.According to such principle, can select for use sorbing materials such as zeolite as catalyst.
Zeolite is one type and has the cage type of rule or the silicon aluminate crystal of pore passage structure, has unique pore passage structure and very big specific area, and effects such as stronger adsorbing separation, ion-exchange, catalysis are arranged.But with zeolite not treated directly be used for decomposing contain O
3Waste gas, its capacity of decomposition is relatively poor.
Decompose O by activated carbon catalysis
3Gas can be known, O
3Decomposition under the thermic condition is unusual the key link, decomposes O if in catalyst, select a kind of specific heat capacity material little, quick heating should be able to bring into play the catalysis thermic better
3Effect.Specific heat capacity table through looking into common material finds that the about 0.8kJ/kg of the specific heat capacity of quartz sand ℃, it is fast relatively to heat up; And the main component of quartz sand is SiO
2, with O
3Do not react stable in properties.Just the specific area of quartz sand is little, is inappropriate for and makes adsorbent.
Summary of the invention
The present invention is the problem that exists in the above-mentioned prior art in order to solve, and the preparation method who provides a kind of novel ozone to decompose composite catalyst and this composite catalyst.This composite catalyst is to be raw material with zeolite and quartz sand, and through making after the iron modification.This composite catalyst can be brought into play quartz sand intensification pyrogenicity, improves thermic and decomposes O
3Effect, can bring into play modified zeolite absorption decomposition again.
The present invention is that hardening agent is carried on the zeolite with the nano-hydroxy iron oxide, constitutes to possess the catalyst that adsorbs capacity of decomposition more by force, and combines O
3Decomposition mechanism and expansion result of study have confirmed that to divide analgesic be thermal source, are warming up to 60～75 ℃ decomposition approach.Composite catalyst is by the alkalization modified quartz sand of iron ion, and nano-hydroxy iron oxide modified zeolite constitutes, and forms O
3Multi-angle capacities of decomposition such as adsorption and enrichment, catalytic decomposition, thermic decomposition.
The present invention realizes through following technical scheme:
A kind of ozone decomposes composite catalyst, is to be that 1:4～4:1 mixed preparing forms by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion by mass ratio.
Zeolite is carried out iron modification (being specially the modification of nano-hydroxy iron oxide), can make zeolite O
3Stronger absorption, capacity of decomposition are arranged, can decompose O thereby zeolite is become
3Catalyst.Simultaneously quartz sand has been carried out iron modification (it is alkalization modified to be specially iron ion), can try hard to improve quartz sand O
3The selective absorption capacity of decomposition, at last itself and modified zeolite are used jointly, thereby form O
3The composite catalyst of multi-angle capacities of decomposition such as adsorption and enrichment, catalytic decomposition, thermic decomposition.
Further, this composite catalyst is to be formed for the 1:1 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.Through experimental verification, when nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion are 1:1 when mixing by mass ratio, the composite catalyst that makes is to O
3Assimilation effect best.
A kind of ozone decomposes the preparation method of composite catalyst; Comprise the preparation of nano-hydroxy iron oxide modified zeolite and the preparation of the alkalization modified quartz sand of iron ion; Wherein, the preparation method of nano-hydroxy iron oxide modified zeolite comprises the steps: (1), is 1.2molL with concentration
-1Iron salt solutions stir, adding concentration in the whipping process is 0.1molL
-1NaOH solution, make pH value of solution reach 2.0～2.5, form the nanocrystal of ferriferous oxide this moment, and stablely be distributed in (ferric hydroxide colloid) in the colloidal dispersion, promptly contain ferrum collosol; (2), zeolite being put into the pH value with solid-liquid mass ratio 1:3 is rare HNO of 5
3In the solution, behind vibration 30min, slowly add the ferrum collosol that contains that makes in the step (1), making zeolite and the volume ratio that contains ferrum collosol is 1:1, keeps vibration 1hr, last centrifugal taking-up zeolite; (3), centrifugal after the zeolite that takes out in the step (2) cleaned at least 3 times with pure water, and behind 110 ℃ of oven dryings, place 400 ℃ of Muffle furnace roasting 2hr again, make nano-hydroxy iron oxide modified zeolite at last; The quartz sand that the preparation method of the alkalization modified quartz sand of iron ion comprises the steps: (1), get after the cleaning places container, and adds pure water, and addition is the 4:5 adding by pure water and quartz sand mass ratio, and then adding concentration again is 2.0molL
-1NaOH solution, addition is that 1:10 adds by NaOH solution and pure water volume ratio; (2), after stirring 1hr under 50 ℃ of conditions of water-bath, dropwise adding concentration is 2.0molL
-1Iron salt solutions, up to system pH=8～9, vibration is taken out quartz sand behind the 30min, after rinsed with deionized water, in 110 ℃ of oven dryings, cooling, makes the alkalization modified quartz sand of iron ion at last.
Described in background technology, active carbon is decomposing O
3The time, active carbon is oxidized, constitutes oxidisability and decomposes, its life-span and validity are difficult to guarantee, can produce multiple accessory substance simultaneously and cause second environmental pollution.Thereby suitable catalyst should be a kind of existing strong adsorption capacity, can enrichment O
3, catalytic decomposition O that again can be strong
3, the material of loss does not take place in and homeostasis.
Therefore, selected for use chromatographic aluminium oxide, lime, kaolin, silica gel, zeolite etc. (removing carbon containing) adsorbent commonly used to O
3Do experiment, though find that these materials are to eliminating O
3Have certain effect; Through the result that under the same terms tail gas measured but compared with active carbon, also have very big gap, do not reach the requirement in the imagination, lime, kaolin play dust too easily; And the composition that aluminium oxide is promptly arranged in the zeolite also has the composition of silica gel; And price is all lower than them, and stable, granularity is moderate, the therefore final raw material of selecting zeolite as composite catalyst of the present invention.But the catalytic effect of zeolite does not reach the requirement in the imagination, and is as shown in Figure 6.
Therefore, need carry out certain modification, with the carrier of zeolite as modified absorbing material to zeolite.Zeolite molecules formula Am [(AlO
2) x (SiO
2) y] n (H
2O), (wherein: A is cations such as Ca, Na, K, Ba, Sr, and m is the cation number; N is a water molecule number, and x is the Al atomicity, and y is the Si atomicity; (y/x) usually between 1～5, (x+y) be tetrahedral number in the unit cell), be one type and have the cage type of rule or the silicon aluminate crystal of pore passage structure; Have unique pore passage structure and big specific area, effects such as stronger adsorbing separation, ion-exchange, catalysis are arranged, be widely used in fields such as water treatment and chemical industry.
O
3A high electron density oxygen atom in the resonant structure of molecule shows strong elecrtonegativity; Al
3+, Fe
3+Deng cation, between them stronger binding ability should be arranged with high electric charge.Bulanin etc. (1995) are through Fourier infrared spectrum method research O
3Absorption, and proof O
3Be decomposed to form elemental oxygen on lewis acid surfaces such as aluminium oxide, iron oxide.Therefore, can select slaines such as iron, aluminium in principle as modifier, but because of containing aluminium oxide in the zeolite, and the form of iron oxide is more stable, the oxide or the load of iron ion form of therefore selecting iron for use, and effect can be better, also more economical.
But because the heat transfer and the particle of zeolite is less than normal, will produce gas through not smooth, local temperature is higher, conducts heat problem such as to be not good at.If select in the catalyst that specific heat capacity is less, quick heating and material that can pay(useful) load iron should be able to bring into play the effect that the catalysis thermic decomposes better.Therefore, find through the specific heat capacity table of looking into common material, the about 0.80J/ of the specific heat capacity of quartz sand (kg ℃), less in non-metal solid, and the main component of quartz sand is SiO
2, with O
3Do not react, stable in properties, the quartz sand adsorption rate behind the load iron can increase by 10 times.If the surface area of not load quartz sand is less, whole adsorption effect will reduce.For this reason, quartz sand has been carried out the modification of iron ion alkalescence, can improve it O
3The selective absorption capacity of decomposition.
Confirm through experimental result, by load zeolite and the composite catalyst that quartz sand is formed of ferriferous oxide to O
3Decomposition efficiency all significantly improve.
Further, described iron salt solutions is FeCl
3Solution, Fe (NO
3)
3Solution or Fe
2(SO
4)
3Solution.
In the preparation process of the alkalization modified quartz sand of said iron ion, the granularity of the quartz sand of use is 0.8～1.2mm, and porosity is 0.41.
Composite catalyst of the present invention is formulated with nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand mixed together of iron ion, has both brought into play quartz sand intensification pyrogenicity, improves thermic and decomposes O
3Effect, brought into play modified zeolite absorption decomposition again.In addition, composite catalyst of the present invention also has the resolution ratio height, and security is good, and self does not consume, long service life, and do not produce advantages such as harmful substance.
Below be the experiment relevant, need to prove that following experiment only plays the illustrative effect to the present invention, the present invention is not done any qualification with the present invention:
1, the analysis of activated carbon catalysis ozone decomposition
1.1 materials and methods
1.1.1 material and instrument
Ozone generator, source of the gas are source of oxygen.
Infrared radiation thermometer.
Chromatography of ions Metrohm 820IC, Switzerland; Elemental analyser Vario EL III (these two Instrument measurings are measured for entrusting).
Decompose post, filling department divides caliber 18mm, the about 75mm of catalyst packing height; Three catalyst decomposes are handled post and are connected in series loading catalyst 12g in every pillar.
Paniculate coal activated carbon (active carbon Co., Ltd of Shanxi Xinhua) is removed surface powder with water washing, and dry under 110 ℃ condition the washing back; The basic parameter of active carbon, specific area 897m
2G
-1, micropore volume 0.43 cm
3G
-1, carbon tetrachloride adsorptive value>=54%, iodine number 850～1100mgg
-1, the about 2.0～2.5mm of particle diameter, porosity 42%, intensity>=90%, ash content 5～18%.
Zeolite is the artificial particulate zeolites of SILVER REAGENT.
Quartz sand: granularity is 0.8-1.2mm, porosity 0.41.
It is pure that reagent such as NaOH, iron chloride is analysis.
1.1.2 method
1.1.2.1 catalytic decomposition ozone approach
Catalytic decomposition O
3Adopt three grades of decomposition post series connection, each decomposes between the post and connects with the silicone tube that can disassemble, and valve, flow device, device for absorbing tail gas etc. are set.Decompose testing arrangement connection sketch map and see Fig. 1.Three grades of decomposition posts all adopt glass tube, can peg graft, and are convenient in the observational study decomposition posts at different levels catalyst to O
3Decomposition effect and correlated characteristic, like CO
2Deng release and the catalyst heating phenomenon of gas in tail gas etc.
O
3Generator is selected the generator of source of oxygen capable of using as source of the gas for use.Wherein the oxygen flow as source of the gas is 1.2～2.5Lmin
-1, flow is controlled by flowmeter, keeps stable in the test relatively.Decomposing experiment beginning back O
3Producing method for determination of amount is that every 15min is with O
3After the KI solution absorption, use iodometric determination, get its mean value after the calculating, as O in the experimentation
3Generating capacity (but decompose continuously in the experiment only test beginning and the O when finishing
3Generating capacity, and get its mean value as O in the experimentation
3Generating capacity).Tail gas after catalytic decomposition gets into the absorption bottle that KI solution is housed, and utilizes KI solution absorption, detection, adds behind the starch as no change color (becoming blue), then shows O
3Decomposition efficiency reaches 100%; Otherwise with the O in the iodometric determination absorption liquid
3Content.
1.1.2.2 variations in temperature
The mensuration of variations in temperature is according to decomposing testing process; Mark a site as the thermometric site at a distance from 1.5cm with first resolution process post is every during contact catalyst along airflow direction from beginning; Get 5 sites such as Fig. 2 altogether; Orientate site a, site b, site c, site d, site e successively as, use the infrared radiation thermometer thermometric at interval, operation continuously, mensuration 60min or longer time according to certain hour.Require infrared radiation thermometer apart from site 2cm during thermometric, vertical direction is measured in the site.
1.1.2.3 CO
2Generation is measured
Catalyst packed into decompose in the post,, weigh at 110 ℃ of oven dry 1hr.Open O after connecting device by Fig. 1
3Generator, timing, tail gas is by 400mL 0.01molL
-1The NaOH solution absorption, change absorption liquid behind the certain hour, in absorption liquid, pipette the 5ml sample to the 50ml colorimetric cylinder, be diluted to scale, to be measured.
CO
2Generation is measured by TOC analyzer (Tianjin, island), and contrasts the wherein difference of TC and IC, confirm whether to exist in the absorption liquid other forms of can absorbed carbonaceous material.
Before the experiment and after the experiment end, the resolution process post that will fill catalyst is respectively weighed with 110 ℃ of oven dry 1hr, calculates the active carbon loss amount.
1.1.2.4 ion chromatography
O
3Decomposable process is the same, with 0.01molL
-1NaOH be absorption liquid, absorb the tail gas of different decomposition time period; Take off behind the absorption bottle with 1molL
-1HCl regulates about pH to 7, with ion chromatography anion-content wherein.
1.2 result of study and discussion
1.2.1 catalytic decomposition efficient
Connect and decompose testing arrangement such as Fig. 1, handle the O of post through the catalytic decomposition of having filled active carbon
3Air flow rate is 1.4～1.6Lmin
-1, O
3Amount 7.8～9.8 mgmin
-1, through three grades of resolution process posts.After operating steadily, break off the pipeline after one-level is handled post, will feed the tail gas absorption bottle, measure wherein O through the residual gas behind the one-level processing post
3Residual volume is 0.38～0.43 mgmin
-1After measuring the decomposition situation, system is connected like Fig. 1 again, after operating steadily, break off series connection two stage treatment post, will feed the tail gas absorption bottle, measure and obtain O through the residual gas behind the one-level processing post
3Residual volume is 0.01～0.02 mgmin
-1Decompose still fully inadequately, the corresponding time of staying of this moment is about about 0.6～0.7Sec.After measuring the decomposition situation, system is connected like Fig. 1 again, after operating steadily, the O of tail gas behind the mensuration series connection tertiary treatment post
3Residual volume has been reduced to 0 mgmin
-1Continue the operation decomposer, absorb three grades of tail gas behind the series connection resolution process post with liquor kalii iodide, move 3～7hr continuously, KI solution nondiscolouring in the absorption bottle utilizes O in the iodometric titrationiodimetry titration test absorption liquid
3Content, the result shows O
3Residual is 0, O
3Resolution ratio reaches 100%, and said determination genus accumulative total absorbs the result.This experimental provision and wherein used O under these conditions are described
3Distintegrant decomposes respond well and stable.
1.2.2 the resolution process column temperature changes
In catalytic decomposition process, the temperature of resolution process post raises gradually.Through measuring, find to heat up and mainly concentrate on first order resolution process post in system's running, and temperature rising rapid speed in the preceding 15min, keep higher temperature afterwards, change very little in time.As shown in Figure 3, reaction begins to 15min, and each site temperature of first order resolution process post all raises rapidly, and the intensification order is basically: site a>site b>site c>site d>site e.The intensification foreground concentrates between site a, the site b, and wherein first order resolution process column temperature is up to about 65 ℃.Before and after site a, the site b should be to contain O
3O when gas contacts with distintegrant
3The position that content is the highest.Variations in temperature reduces afterwards, and the mensuration temperature on the corresponding site tends towards stability.All the other two-stage resolution process column temperature slightly improve between 27.9～30.1 ℃ than room temperature, remain unchanged basically.
Heat up and mainly to occur in O when contacting with distintegrant
3Near the higher position of content, these positions and near O
3Decomposed rapidly, make follow-up distintegrant contact O
3Concentration descend, along with contact O
3The minimizing of dosage, decomposition reaction (2O
3==3O
2) the speed reduction, liberated heat reduces, and the difference of the intensification phenomenon of follow-up location site d and site e is not obvious, at this moment O
3Concentration also become very little.
1.2.3 mass loss of resolution process post and active carbon constituent analysis
I have measured CO in resolution process post reaction front and back mass change, the decomposed tail gas absorption liquid
2Generation and anionic output.
The quality of activated carbon of measuring in three grades of resolution process posts changes.The result shows, the active carbon in three grades of resolution process posts behind cartalytic decomposition effect after a while all has certain quality to reduce, like Fig. 4.In conjunction with before 15min variations in temperature and to three grades of resolution process posts decomposition efficiency explanation O step by step
3Decomposition reaction mainly occur in the first order resolution process post, explanation simultaneously is depleted as the activity of such catalysts charcoal.
Be used for catalytic decomposition O
3Active carbon be coal mass active carbon, it is carried out elementary analysis.Through determination of elemental analysis, without decomposing O
3Active carbon in the mass fraction of C be 81.23%, be essential element; Wherein also have 5.31% N and 9.72% O, other are lower like S, Fe, Ca, P, K equal size.
TOC and ion chromatography result confirm, contain CO in the tail gas absorption liquid really
2And NO
3 -The two productive rate is the highest when being initial decomposition, and the back is along with descend running time gradually; Show O
3With activated carbon substrate reaction having taken place, has caused the variation of active carbon structure and the minimizing of quality, and produced NO
xHarmful substance like Fig. 5, causes secondary pollution to environment.
Heat produces oxidation and the O that mainly comes from C in the system
3Self decomposes.Incipient stage, the oxidized heat release of active carbon is simultaneously with O
3Self decomposes heat release, and the resolution process column temperature raises fast.Intensification causes O
3Self decomposition ratio increases, and the whole thermal discharge of system descends.Work as O
3Self decompose with active carbon by O
3Form certain proportion between the oxidation, the two reaches stability, and temperature is basicly stable, no longer obviously rises.When variation of temperature tends towards stability gradually, CO
2Generation speed descend simultaneously, show that active carbon structural element oxidation rate descends; And to keep same O
3Resolution ratio, then O
3Self thermic disassemble to start and wave main effect.
Active carbon has been carried out detailed research to be drawn to draw a conclusion:
(1) decomposition mechanism is divided into three parts: one of which is activated carbon catalysis O
3Be decomposed into O
2, active carbon is brought into play the effect of catalyst therein, and mechanism mainly is that the strong adsorption ability of active carbon causes local location O
3Enrichment, decomposition; Its two active carbons and O
3React, destroyed activated carbon surface structure and group, cause the decline of activated carbon catalysis decomposability; It three is O
3The heat that discharges when being decomposed to form oxygen, carbon dioxide and accessory substance with above-mentioned two kinds of mechanism causes the decomposition region temperature to raise, and further promotes O
3Decompose.
(2) O
3Oxidation Decomposition all be accompanied by variation of temperature with self decomposable process, temperature can be used as O
3An easy and important indication parameter that decomposes.Decompose near the strong space-time site of Shaoxing opera, variations in temperature is also remarkable more.
(3) activated carbon catalysis decomposes O
3Be an exothermic process, thermal discharge and O
3Concentration, catalyst property, air flow rate, speed, structure of reactor etc. are relevant.Under certain conditions, the temperature that heat release causes presents certain spatial and temporal distributions, can also be used for the design of resolution process device through usefulness and security, the stability etc. of this rule research catalyst.
(4) activated carbon catalysis decomposes O
3Produced CO in the process again
2Reach nitrogen oxide etc., caused the loss and the second environmental pollution of catalyst.
2, iron modified zeolite (being nano-hydroxy iron oxide modified zeolite, down together) decomposes O
3Compliance test result
Get 60g and be filled in the glass tube that caliber is 18mm O through the zeolite of iron modification
3Flow is 8～15mgmin
-1, gas flow 1.5 Lmin
-1, time of staying 0.96s, tail gas detects residue O with the KI absorption liquid
3Amount, system moves 5hr, O continuously
3Decomposition efficiency reaches more than 99.5%.With unmodified zeolite filling, resolution ratio is between 85～92% equally.
Get the glass tube that bore is 30mm, with zeolite after the modification and all fillings respectively of unmodified zeolite, tail gas detects O with the titration of KI absorption liquid
3Content, O
3Flow, contain O
3Gas flow, the time of staying, system operation time, decomposition O
3Effect is seen table 1:
Table 1 catalytic decomposition post decomposes O
3Effect
| Catalyst | O 3 mg·min -1 | Flow Lmin -1 | Time of staying s | Running time hr | Resolution ratio % |
| Zeolite | 4.5～7.9 | 1.6 | 1.6 | 3 | 91.7 |
| Modified zeolite | 5.7～9.2 | 1.6 | 1.6 | 5 | 100 |
| Modified zeolite | 4.7～8.2 | 1.6 | 1.6 | 5 | 100 |
| Zeolite | 6.9～9.7 | 2.8 | 0.9 | 3 | 87 |
| Modified zeolite | 7.2～8.7 | 2.8 | 0.9 | 3 | 99.4 |
| Modified zeolite | 6.3～9.5 | 2.8 | 0.9 | 2 | 99.3 |
The decomposer overall operation time that modified zeolite is loaded surpasses 25hr, and effect is still stable, decomposes O
3Efficient is being kept between 99～100%.Through tail gas is carried out alkali lye (0.01molL
-1NaOH) absorb, absorption liquid is carried out the chromatography of ions anion analysis, do not detect anion such as nitrate anion, nitrite anions, sulfate radical, chlorion, fluorine ion, phosphate radical.Zeolite was to O after this example showed modification
3Capacity of decomposition obviously strengthens, and does not see to produce pernicious gas pollutant, stable performance.
3, composite catalyst of the present invention decomposes O
3Compliance test result
With the iron modified zeolite and the iron modification quartz sand of drying (is the alkalization modified quartz sand of iron ion; Down with) be respectively that 1:4,1:2,1:1,2:1,4:1 are mixed and made into four kinds of different composite catalysts and are filled in the resolution process post packed height 80mm with the mass ratio.
Contrast two types of catalyst of independent iron modified zeolite and composite catalyst to O
3Catalytic decomposition efficient.Exhaust flow is 1.6～1.8Lmin
-1, O
3Content 5～6.5mgm
-3In glass tube (caliber 18mm, long 330mm) resolution process device, load composite catalyst and iron modified zeolite respectively, more than the loading height 200mm.Tail gas detects O to tail gas with the titration of KI absorption liquid through the resolution process device
3Content, clearance is always 100%.Tail gas is carried out alkali lye (0.01molL
-1NaOH) absorb, absorption liquid is carried out the chromatography of ions anion analysis, do not detect anion such as nitrate anion, nitrite anions, sulfate radical, chlorion, fluorine ion, phosphate radical.Install the O behind the different proportion mixed catalyst additional
3Decomposition efficiency, as shown in Figure 6.(explain: improving throughput and be equivalent to the corresponding minimizing time of staying, is exactly to reduce in the reaction time, and decrease in efficiency is a nature, reasonably)
So can be known by Fig. 6 result, when iron modified zeolite and iron modification quartz sand proportioning were 1:1, resolution ratio can reach 99.8%, and absorption efficiency is best, and therefore, the best proportioning of this composite catalyst is 1:1, and the proportioning of 1:1 is used for following experiment.
Monitoring along variations in temperature in the journey pipe shown in following table 2, table 3, table 4:
Table 2 is filled the resolution process device of unmodified zeolite along journey and time variations in temperature
The resolution process device of the filling-modified zeolite of table 3 is along journey and time variations in temperature
Table 4 is filled the resolution process device of composite catalyst along journey and time variations in temperature
Site a～e be respectively by inlet end play 1,3,5,7, the 10cm place.
Early-stage Study shows, O
3Decomposable process is accompanied by variations in temperature, and the space-time site that variations in temperature is big more is neighbouring to be exactly to decompose the most violent space-time site.Contrast unmodified zeolite and modified zeolite decomposition O according to space-time site variations in temperature
3Catalytic capability (table 2, table 3) visible, unmodified zeolite variations in temperature is comparatively slow, and position range is bigger, still after tens minutes, reaches 38 ℃ at the 7cm place; The zeolite range of temperature mainly concentrates on before the 5cm place after the modification, and heats up rapidly.In conjunction with decomposition and absorption liquid O in early stage
3Determination data shows that modified zeolite decomposes O
3Usefulness significantly improve.
The two decomposes O contrast modified zeolite and composite catalyst
3Catalytic capability (table 3, table 4) visible; The part that significantly heats up in the resolution process post that composite catalyst is filled mainly was before 5cm; And the intensification of 5cm place is still very obvious in the resolution process post that modified zeolite is filled, and shows that composite catalyst is than modified zeolite catalytic decomposition O
3Ability is strong.In addition, the resolution process post maximum temperature that composite catalyst is filled is high than modified zeolite, be respectively 72.8 ℃ and 67.9 ℃, and environment temperature is respectively 25.1 ℃ and 25.8 ℃, shows that composite catalyst catalytic decomposition ability is strong.
Description of drawings
Fig. 1 is the Experimental equipment of activated carbon catalysis ozone decomposition.
Fig. 2 is the site signature on the resolution process post.
Fig. 3 is CO
2Produce speed and temperature change in time and space relation.
Fig. 4 is a quality of activated carbon variation diagram in the resolution process post.
Fig. 5 be NOx output over time.
Fig. 6 is that different catalysts is to O
3Resolution ratio figure.
Among the figure: 1-oxygenerator, 2-ozone generator, 3-flow controller, 4-catalytic decomposition one-level, 5-catalytic decomposition secondary, three grades of 6-catalytic decomposition, 7-absorption liquid, alpha-position point a, b-site b, c-site c, d-site d, e-site e.
The specific embodiment
Below in conjunction with specific embodiment the present invention is done description further:
A kind of ozone decomposes composite catalyst, is to be formed for the 1:4 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.
This ozone decomposes the preparation method of composite catalyst; Comprise the preparation of nano-hydroxy iron oxide modified zeolite and the preparation of the alkalization modified quartz sand of iron ion; Wherein, the preparation method of nano-hydroxy iron oxide modified zeolite comprises the steps: (1), is 1.2molL with concentration
-1FeCl
3Solution stirring, adding concentration in the whipping process is 0.1molL
-1NaOH solution, make pH value of solution reach 2.0～2.5, form the nanocrystal of ferriferous oxide this moment, and stable being distributed in the colloidal dispersion, promptly contain ferrum collosol; (2), zeolite being put into the pH value with solid-liquid mass ratio 1:3 is rare HNO of 5
3In the solution, behind vibration 30min, slowly add the ferrum collosol that contains that makes in the step (1), making zeolite and the volume ratio that contains ferrum collosol is 1:1, keeps vibration 1hr, last centrifugal taking-up zeolite; (3), centrifugal after the zeolite that takes out in the step (2) cleaned at least 3 times with pure water, and behind 110 ℃ of oven dryings, place 400 ℃ of Muffle furnace roasting 2hr again, make nano-hydroxy iron oxide modified zeolite at last; The preparation method of the alkalization modified quartz sand of iron ion comprises the steps: (1), gets granularity is that 1.1mm, porosity are 0.41 quartz sand; Cleaning is placed in the container; And the adding pure water, addition is that 4:5 adds by pure water and quartz sand mass ratio, then adding concentration again is 2.0molL
-1NaOH solution, addition is that 1:10 adds by NaOH solution and pure water volume ratio; (2), after stirring 1hr under 50 ℃ of conditions of water-bath, dropwise adding concentration is 2.0molL
-1FeCl
3Solution up to system pH=8～9, takes out quartz sand behind the vibration 30min, after rinsed with deionized water, in 110 ℃ of oven dryings, cooling, makes the alkalization modified quartz sand of iron ion at last.
A kind of ozone decomposes composite catalyst, is to be formed for the 1:2 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.
The preparation method that this ozone decomposes composite catalyst is identical with the preparation method among the embodiment 1, and difference is: employed iron salt solutions is Fe
2(SO
4)
3Solution, employed quartz sand size are 0.9mm.
A kind of ozone decomposes composite catalyst, is to be formed for the 1:1 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.
The preparation method that this ozone decomposes composite catalyst is identical with the preparation method among the embodiment 1, and difference is: employed quartz sand size is 1.0mm.
Embodiment 4
A kind of ozone decomposes composite catalyst, is to be formed for the 2:1 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.
The preparation method that this ozone decomposes composite catalyst is identical with the preparation method among the embodiment 1, and difference is: employed iron salt solutions is Fe (NO
3)
3Solution, employed quartz sand size are 0.8mm.
Embodiment 5
A kind of ozone decomposes composite catalyst, is to be formed for the 4:1 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.
The preparation method that this ozone decomposes composite catalyst is identical with the preparation method among the embodiment 1, and difference is: employed iron salt solutions is Fe (NO
3)
3Solution, employed quartz sand size are 1.2mm.
Claims (5)
1. an ozone decomposes composite catalyst, it is characterized in that: this composite catalyst is to be that 1:4～4:1 mixed preparing forms by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion by mass ratio.
2. a kind of ozone according to claim 1 decomposes composite catalyst, and it is characterized in that: this composite catalyst is to be formed for the 1:1 mixed preparing by mass ratio by nano-hydroxy iron oxide modified zeolite and the alkalization modified quartz sand of iron ion.
3. an ozone decomposes the preparation method of composite catalyst; It is characterized in that: comprise the preparation of nano-hydroxy iron oxide modified zeolite and the preparation of the alkalization modified quartz sand of iron ion; Wherein, the preparation method of nano-hydroxy iron oxide modified zeolite comprises the steps: (1), is 1.2molL with concentration
-1Iron salt solutions stir, adding concentration in the whipping process is 0.1molL
-1NaOH solution, make pH value of solution reach 2.0～2.5, form the nanocrystal of ferriferous oxide this moment, and stable being distributed in the colloidal dispersion, promptly contain ferrum collosol; (2), zeolite being put into the pH value with solid-liquid mass ratio 1:3 is rare HNO of 5
3In the solution, behind vibration 30min, slowly add the ferrum collosol that contains that makes in the step (1), making zeolite and the volume ratio that contains ferrum collosol is 1:1, keeps vibration 1hr, last centrifugal taking-up zeolite; (3), centrifugal after the zeolite that takes out in the step (2) cleaned at least 3 times with pure water, and behind 110 ℃ of oven dryings, place 400 ℃ of Muffle furnace roasting 2hr again, make nano-hydroxy iron oxide modified zeolite at last; The quartz sand that the preparation method of the alkalization modified quartz sand of iron ion comprises the steps: (1), get after the cleaning places container, and adds pure water, and addition is the 4:5 adding by pure water and quartz sand mass ratio, and then adding concentration again is 2.0molL
-1NaOH solution, addition is that 1:10 adds by NaOH solution and pure water volume ratio; (2), after stirring 1hr under 50 ℃ of conditions of water-bath, dropwise adding concentration is 2.0molL
-1Iron salt solutions, up to system pH=8～9, vibration is taken out quartz sand behind the 30min, after rinsed with deionized water, in 110 ℃ of oven dryings, cooling, makes the alkalization modified quartz sand of iron ion at last.
4. a kind of ozone according to claim 3 decomposes the preparation method of composite catalyst, and it is characterized in that: described iron salt solutions is FeCl
3Solution, Fe (NO
3)
3Solution or Fe
2(SO
4)
3Solution.
5. according to the preparation method of claim 3 or 4 described a kind of ozone decomposition composite catalysts, it is characterized in that: in the preparation process of the alkalization modified quartz sand of said iron ion, the granularity of the quartz sand of use is 0.8～1.2mm, and porosity is 0.41.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210143136.9A CN102671688B (en) | 2012-05-10 | 2012-05-10 | Ozone decomposition composite catalyst and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210143136.9A CN102671688B (en) | 2012-05-10 | 2012-05-10 | Ozone decomposition composite catalyst and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102671688A true CN102671688A (en) | 2012-09-19 |
| CN102671688B CN102671688B (en) | 2014-12-17 |
Family
ID=46804628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210143136.9A Expired - Fee Related CN102671688B (en) | 2012-05-10 | 2012-05-10 | Ozone decomposition composite catalyst and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102671688B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1465427A (en) * | 2002-07-02 | 2004-01-07 | 中国科学院生态环境研究中心 | Catalyzing method for eliminating O3 and simutaneously eliminating O3 and CO |
| CN102557062A (en) * | 2012-01-15 | 2012-07-11 | 山西大学 | Modified zeolite for degrading ozone-containing waste gas and preparation method for modified zeolite |
-
2012
- 2012-05-10 CN CN201210143136.9A patent/CN102671688B/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1465427A (en) * | 2002-07-02 | 2004-01-07 | 中国科学院生态环境研究中心 | Catalyzing method for eliminating O3 and simutaneously eliminating O3 and CO |
| CN102557062A (en) * | 2012-01-15 | 2012-07-11 | 山西大学 | Modified zeolite for degrading ozone-containing waste gas and preparation method for modified zeolite |
Non-Patent Citations (1)
| Title |
|---|
| SEIICHIRO IMAMURA ETAL.: "《Decomposition of ozone on a silver catalyst》", 《IND. ENG. CHEM. RES.》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102671688B (en) | 2014-12-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Valdés et al. | Role of surface hydroxyl groups of acid-treated natural zeolite on the heterogeneous catalytic ozonation of methylene blue contaminated waters | |
| Zhang et al. | Removal of ammonium from aqueous solutions using zeolite synthesized from fly ash by a fusion method | |
| Qing | Study on the adsorption of lanthanum (III) from aqueous solution by bamboo charcoal | |
| US7479230B2 (en) | Process for reduction of inorganic contaminants from waste streams | |
| CN105541009B (en) | A kind of processing method of anionic azo dyes waste water | |
| Shalaby et al. | Rice husk templated water treatment sludge as low cost dye and metal adsorbent | |
| Inglezakis et al. | Effects of pretreatment on physical and ion exchange properties of natural clinoptilolite | |
| CN103482624B (en) | Preparation method for active carbon with photocatalysis function | |
| Wu et al. | Enhanced removal of ammonium from the aqueous solution using a high-gravity rotating packed bed loaded with clinoptilolite | |
| Mi et al. | Enhanced adsorption of orange II using cationic surfactant modified biochar pyrolyzed from cornstalk | |
| Chen et al. | Fabricating efficient porous sorbents to capture organophosphorus pesticide in solution | |
| Kurkumin et al. | Boron removal from aqueous solution using curcumin-impregnated activated carbon | |
| Liu et al. | Treatment of an industrial chemical waste‐water using a granular activated carbon adsorption‐microwave regeneration process | |
| Al-Harahsheh et al. | Sulfur dioxide removal using natural zeolitic tuff | |
| Shen et al. | Preparation and ion exchange properties of egg-shell glass beads with different surface morphologies | |
| CN105944658B (en) | Preparation method of granular cesium removal inorganic ion adsorbent, product and application | |
| Cheng et al. | Removal of simulated radionuclide Ce (III) from aqueous solution by as-synthesized chrysotile nanotubes | |
| Hamadneh et al. | Comparison of Jordanian and standard diatomaceous earth as an adsorbent for removal of Sm (III) and Nd (III) from aqueous solution | |
| Manirajah et al. | Evaluation of low cost-activated carbon produced from waste tyres pyrolysis for removal of 2-chlorophenol | |
| CN112108117B (en) | Preparation method and testing device for simultaneously removing multiple radioactive metal carbon-based composite materials | |
| CN108993533B (en) | Preparation method of toluene low-temperature combustion catalyst and toluene low-temperature combustion catalyst | |
| CN102671688B (en) | Ozone decomposition composite catalyst and preparation method thereof | |
| CN109289508A (en) | A kind of preparation method of high hydrophobicity zeolitic material | |
| Mačala et al. | Clinoptilolite as a mineral usable for cleaning of exhaust gases | |
| Fungaro | Surfactant-modified zeolites from coal fly and bottom Ashes as adsorbents for removal of crystal violet from aqueous solution |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20141217 Termination date: 20180510 |