CN107159684A - Domestic garbage incineration flyash and discarded SCR catalyst coprocessing system and method - Google Patents

Abstract

The invention provides a co-processing system for domestic waste incineration fly ash and waste SCR catalyst, including an ozone generating device and a fly ash catalytic oxidation device, etc. The fly ash catalytic oxidation device is provided with a gas inlet, a fly ash inlet, a gas outlet and a fly ash The waste SCR catalytic oxidation device is provided with an air inlet and an air outlet. The gas inlet is connected to the ozone generator, the gas outlet is connected to the air inlet of the waste SCR catalytic oxidation device, and the fly ash outlet is connected to the fly ash collection device. A spiral blade and a fly ash heating device are respectively arranged in the inner chamber of the ash catalytic oxidation device, a catalyst assembly is arranged in the waste SCR catalytic oxidation device, and an exhaust gas heating device is arranged in the inner chamber of the waste SCR catalytic oxidation device. The invention also simultaneously provides a method for synergistic treatment of domestic waste incineration fly ash and waste SCR catalyst by using the above treatment system.

Description

System and method for co-processing domestic waste incineration fly ash and waste SCR catalyst

technical field

The invention belongs to the technical field of environmental protection, and mainly relates to a system and method for synergistic treatment of domestic waste incineration fly ash and waste SCR catalyst.

Background technique

At present, domestic waste disposal has become a major social problem. The annual output of municipal solid waste in the country exceeds 150 million tons, and the harmless treatment rate is only about 54%, which poses a great threat to the ecological environment and people's health. Due to the fast speed of domestic waste incineration, small footprint, and significant reduction and harmless effects, it has been widely used in medium and large cities in my country where urban land is generally in short supply and pressure on domestic waste disposal is high. However, the residue after domestic waste incineration-fly ash usually contains toxic and harmful pollutants such as dioxins and heavy metals. Key factor.

There are many sources of dioxins, among which waste incineration is an important source of dioxin emissions. Emissions from Europe, the United States, and Japan show that incineration sources account for a high proportion of dioxin emissions. Japan's dioxin emissions from incineration sources still accounted for 63% of the total emissions in 2004. According to the experimental data published in China, the dioxin emissions from domestic waste incineration are estimated. Assuming that the incinerator runs for 330 days a year, the flue gas production rate of domestic waste incineration is 5500Nm ³ /t, the fly ash production rate is 3%, and the smoke production rate is 3%. Dioxin in the air reaches the national standard of 1.0ng(I-TEQ)/m ³ , and dioxin in the fly ash is 2.0ng(I-TEQ)/g, then it can be calculated that the current domestic waste incineration in China is discharged into the atmosphere The total amount of dioxins is about 54.45g(I-TEQ)/a, and the total amount of dioxins discharged through fly ash is about 594.0g(I-TEQ)/a, which is equivalent to 10 times the amount of flue gas emissions many. Therefore, the treatment and disposal of dioxins in incineration fly ash is particularly important.

The dioxins generated in the waste incineration process are mainly concentrated in the flue gas and fly ash. The control technologies for dioxins in the flue gas include: (1) activated carbon adsorption and high-efficiency dust removal. The huge specific surface area and good adsorption of activated carbon can not only adsorb gaseous and solid dioxins. At present, the flue gas purification system usually injects activated carbon powder into the front pipe of the dust collector to absorb flue gas dioxins, which are captured by the dust collector downstream. However, the essence of activated carbon adsorption technology is to capture and separate dioxins and transfer them to the solid phase (fly ash, activated carbon). The activated carbon that has adsorbed dioxins must be further treated harmlessly. The amount has no reduction effect. (2) Selective catalytic reduction (SCR). SCR is widely used in coal-fired power plants to redox _NOx in flue gas. At present, SCR is installed in some waste incineration facilities. Studies have shown that SCR can decompose dioxin while denitrifying, and the decomposition products are CO ₂ , H ₂ O and HCl. (3) Advanced oxidation. Studies have shown that photocatalytic oxidation is effective for the degradation of dioxins in the gaseous state, and the degradation rate of the total amount and toxic equivalent is above 50%. Plasma oxidation has attracted widespread attention because of its strong oxidation ability and good degradation effect. Among the above flue gas control technologies, the first two are relatively mature and have been commercially applied, while the latter two are still in the experimental stage. The first activated carbon adsorption plus bag dust removal technology only captures and separates dioxins, and has no effect on reducing the total amount of dioxins; the latter three technologies are gas-phase in-situ dioxin degradation technologies, but each has its own Disadvantages: In SCR technology, catalyst poisoning is the key to affecting its stable operation; ultraviolet light technology has low removal efficiency due to energy efficiency, and it is possible to transform into practical application technology only by further improving reaction efficiency through other methods; and plasma Oxidation technology must further improve the stability of the reactor and reduce its equipment and operating costs before it can be put into commercial promotion.

The control techniques for dioxins in fly ash include: (1) high temperature melting method. The high temperature environment is used to completely decompose and destroy the dioxins in the fly ash, so as to achieve the purpose of reducing dioxins. The higher the melting temperature, the higher the decomposition rate, while the decomposition rate in an oxidizing atmosphere is higher than that in an inert atmosphere. (2) Low temperature heat treatment. It refers to the method of degrading dioxins in fly ash through hydrogenation/dechlorination and decomposition in a relatively low temperature area with a processing temperature of 300-600 ° C and maintaining a certain processing time in an inert atmosphere or an oxidizing atmosphere. (3) Supercritical water and hydrothermal degradation. Hydrothermal degradation technology is similar to supercritical water oxidation technology. When water is used as the medium, supercritical water can be obtained when the temperature is >374°C and the pressure is >22.1MPa. In this state, there is no gas-liquid interface mass transfer resistance, which improves The reaction efficiency achieves complete oxidation, while the hydrothermal state is in a subcritical state, and the temperature and pressure of water are lower than the above critical value. In this state, the solubility of organic matter in water, [H ⁺ ], [OH ^- ] increases significantly, and can occur A reaction that cannot proceed at room temperature. (4) Alkali chemical decomposition method. The chemical decomposition method, also known as the BCD method, is suitable for the harmless treatment of soil contaminated by dioxin-like compounds. (5) Plasma method. Plasma is divided into thermal plasma and non-thermal plasma according to its properties. Thermal plasma is high-temperature plasma, which generates a high temperature of 1400°C through high-temperature plasma to melt waste incineration fly ash. This method has a very high degradation rate for dioxins, usually above 99.9%. (6) Photolysis method. Under the irradiation of ultraviolet light, the benzene ring of dioxin molecules can be dechlorinated to carry out photodegradation treatment. (7) Biodegradation method. Dioxins are highly resistant to microbial degradation, and only 5% of microbial strains in nature can decompose dioxins. (8) Mechanochemical method. It refers to the treatment method that applies mechanical energy to condensed matter such as solid and liquid by means of shearing, friction, impact, extrusion, etc., and induces changes in its structure and physical and chemical properties. The above are the technologies for the degradation of dioxins in fly ash. Compared with the flue gas treatment technologies, the technologies for the treatment of dioxins in solid phase media are more abundant, but among them, only those that can be applied on a large scale are: high temperature melting technology, Low-temperature heat treatment and alkali chemical decomposition are three technologies. Among them, the high-temperature melting technology can decompose dioxins in fly ash and solidify the heavy metals contained in it at the same time, which has excellent treatment effect. However, this technology consumes a lot of energy, and the equipment costs are expensive; low-temperature heat treatment technology generally has a degradation rate of more than 90% for fly ash dioxins, and its equipment investment and operating costs are relatively low. It has been put into industrial use in some waste incineration plants in Japan and Germany. Application: Alkali chemical decomposition is mainly used in the harmless treatment of soil, and the removal rate of dioxin can reach more than 90%, but the process is cumbersome, and NaHCO ₃ and organic solvents need to be added as additives in the intermediate process. Several other degradation technologies are still difficult to put into industrial application due to their own shortcomings.

The SCR catalyst is a conventional catalyst whose basic composition is V2O5-WO3-TiO2. It is generally believed that when the catalytic activity of the SCR catalyst drops to 80% of its original value, it can be considered that the catalyst has been deactivated and becomes a waste SCR catalyst. At present, there are two main ways to deal with waste SCR catalysts: (1) directly discard as hazardous waste, accounting for about 70% of the total catalyst; (2) recycle after pretreatment, such as washing-drying-crushing, and reprocessing Back to the new catalyst preparation, this accounted for about 30% of the total catalyst. The utilization efficiency of the SCR catalyst is low.

Therefore, it is necessary to improve the prior art.

Contents of the invention

The technical problem to be solved by the present invention is to provide an efficient system and method for co-processing domestic waste incineration fly ash and waste SCR catalyst.

In order to solve the above technical problems, the present invention provides a co-processing system for domestic waste incineration fly ash and waste SCR catalyst, including fly ash feeding device, ozone generating device, fly ash catalytic oxidation device, waste SCR catalytic oxidation device and fly ash collection device; the fly ash catalytic oxidation device is provided with a gas inlet, a fly ash inlet, a gas outlet and a fly ash outlet; the waste SCR catalytic oxidation device is provided with an air inlet and an air outlet; the gas inlet and the ozone generator The device is connected, the gas outlet is connected with the air inlet of the waste SCR catalytic oxidation device, and the fly ash outlet is connected with the fly ash collection device;

The inner cavity of the fly ash catalytic oxidation device is respectively provided with a spiral blade and a fly ash heating device;

The fly ash feeding device includes an ash hopper and a fly ash quantitative feeder communicated with the discharge port of the ash hopper; the fly ash quantitative feeder communicates with the fly ash inlet;

The waste SCR catalytic oxidation device is provided with at least one catalyst assembly, and the catalyst assembly is connected to the inner wall of the waste SCR catalytic oxidation device; an exhaust gas heating device is provided in the inner cavity of the waste SCR catalytic oxidation device.

As an improvement to the co-processing system of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the air outlet of the waste SCR catalytic oxidation device is provided with an induced draft fan.

As a further improvement to the co-processing system of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the waste SCR catalytic oxidation device is provided with an openable and closable opening that cooperates with the catalyst assembly, and the catalyst assembly is inserted or pulled out from the opening.

As a further improvement to the co-processing system of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the catalyst assembly is composed of a catalyst layer composed of waste SCR catalyst and porous stainless steel plates arranged on both sides of the catalyst layer, and the thickness of the catalyst layer is 5 ~ 10mm, and the pore diameter of the porous stainless steel plate is 0.3-0.4mm; the waste SCR catalyst is a particle with a particle diameter of 0.5-1mm.

The present invention also provides a co-processing method for domestic waste incineration fly ash and waste SCR catalyst, comprising the following steps:

The fly ash is added to the fly ash quantitative supplier through the ash hopper, and the fly ash quantitative supplier feeds the fly ash to the fly ash catalytic oxidation device through the fly ash inlet; at the same time, the ozone generator generates ozone, and the ozone enters the fly ash catalytic oxidation from the gas inlet device;

Fly ash and ozone are stirred and mixed by spiral blades in the fly ash catalytic oxidation device, and at the same time slowly move to the gas outlet and fly ash outlet. During this process, the dioxins contained in the fly ash are degraded into CO ₂ by catalytic oxidation of ozone. , H ₂ O and HCl, or decomposed into gaseous low-molecular-weight and low-toxic organic substances;

The fly ash treated by the fly ash catalytic oxidation device enters the fly ash collection device through the fly ash outlet, and the exhaust gas treated by the fly ash catalytic oxidation device enters the waste SCR catalytic oxidation device through the gas outlet and the air inlet, and the gaseous organic matter in the exhaust gas is discarded In the SCR catalytic oxidation device, after the catalytic oxidation of the catalyst layer, it is finally degraded into harmless CO ₂ and H ₂ O, and the treated clean gas is discharged from the gas outlet under the action of the induced draft fan.

As an improvement to the co-processing method of domestic waste incineration fly ash and waste SCR catalyst in the present invention: the fly ash treated by the fly ash catalytic oxidation device in the fly ash collection device is then solidified and stabilized, so as to remove the processed fly ash contained heavy metals.

As a further improvement to the co-processing method of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the residence time of fly ash in the fly ash catalytic oxidation device is greater than 1min, and the ratio of the amount of ozone and fly ash added in the fly ash catalytic oxidation device is 0.1 ~0.5g ozone/kg fly ash.

As a further improvement to the co-processing method of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the fly ash heating device is used to heat fly ash and ozone in the fly ash catalytic oxidation device, and the heating temperature is 50-90°C.

As a further improvement to the co-processing method of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the waste gas heating device is used to heat the waste gas in the waste SCR catalytic oxidation device, the heating temperature is 90-200 °C, and the gas air in the waste SCR catalytic oxidation device is The speed is 5000～10000/h.

As a further improvement to the co-processing method of domestic waste incineration fly ash and waste SCR catalyst of the present invention: the solidification and stabilization treatment is cement solidification, lime solidification or chemical stabilization.

The technical advantage of the present invention is:

1. The system and method for synergistic treatment of domestic waste incineration fly ash and waste SCR catalyst of the present invention utilizes the catalytic performance of fly ash itself, combined with ozone oxidation, to degrade dioxin-like organic substances in domestic waste incineration fly ash into harmless or Low-toxic substances, and then use the catalytic oxidation performance of the SCR catalyst to deeply oxidize the low-toxic substances that are not completely degraded at the front end, and finally solve the problem of dioxin pollution in fly ash;

2. Using the waste SCR catalyst as the catalyst for the advanced treatment of exhaust gas realizes the reuse of the SCR catalyst and improves the utilization efficiency of the SCR catalyst;

3. Utilize the catalytic properties of the metal substances contained in the fly ash itself, combined with the auxiliary effect of ozone, to efficiently decompose the dioxin in the fly ash on site, and provide a new solution for incineration fly ash treatment.

Description of drawings

The specific implementation manners of the present invention will be described in further detail below in conjunction with the accompanying drawings.

Fig. 1 is a schematic structural diagram of a co-processing system for domestic waste incineration fly ash and waste SCR catalyst;

Fig. 2 is the graph of the ozone addition rate and dioxin degradation rate of fly ash catalytic oxidation device 3;

Fig. 3 is a graph showing the reaction temperature and dioxin degradation rate of the fly ash catalytic oxidation device 3.

detailed description

The present invention will be further described below in conjunction with specific examples, but the protection scope of the present invention is not limited thereto.

Embodiment 1, the co-processing system of domestic waste incineration fly ash and waste SCR catalyst, as shown in Figure 1-3, includes an ozone generator 2, a fly ash feeding device 1, a fly ash catalytic oxidation device 3, and a fly ash collection device 5 and waste SCR catalytic oxidation device 4 . The fly ash catalytic oxidation device 3 is provided with a gas inlet 32 , a fly ash inlet 31 , a gas outlet 33 and a fly ash outlet 34 , and the waste SCR catalytic oxidation device 4 is provided with an air inlet 41 and an air outlet 42 . The gas inlet 32 communicates with the ozone generator 2, the fly ash inlet 31 communicates with the fly ash feeding device 1, the gas outlet 33 communicates with the air inlet 41 of the waste SCR catalytic oxidation device 4, and the fly ash outlet 34 communicates with the fly ash collecting device 5 connected.

A helical blade 35 is arranged in the inner cavity of the fly ash catalytic oxidation device 3, and the helical blade 35 is driven by a self-contained motor, so that the fly ash and ozone slowly move from the fly ash inlet 31 to the fly ash outlet 34 under stirring; the fly ash The inner wall of the catalytic oxidation device 3 is equipped with a fly ash heating device 36. The fly ash heating device 36 is an electric heating layer with a heating temperature of 50-90°C. The fly ash heating device 36 can heat the fly ash in the fly ash catalytic oxidation device 3. Ash, enhanced catalytic oxidation. Since ozone decomposes rapidly after exceeding 100° C., the temperature of the fly ash heating device 36 is controlled below 90° C. to ensure that ozone will not be decomposed rapidly.

The fly ash feeding device 1 includes an ash hopper 11 and a fly ash quantitative feeder 12 communicated with the discharge port of the ash hopper 11, the fly ash quantitative feeder 12 includes a storage bin and a weighing device arranged below the storage bin, The weighing device weighs the fly ash in the storage bin. A discharge valve is provided under the storage bin. The storage bin communicates with the ash hopper 11 , and the discharge valve communicates with the fly ash inlet 31 . The fly ash enters the fly ash quantitative feeder 12 through the ash hopper 11 , and the fly ash quantitative feeder 12 controls the amount of fly ash added to the fly ash catalytic oxidation device 3 .

The waste SCR catalytic oxidation device 4 is provided with at least one catalyst assembly 43, the catalyst assembly 43 includes a catalyst layer composed of waste SCR catalyst, the thickness of the catalyst layer is 5-10mm, and the two sides of the catalyst layer are porous stainless steel plates with a diameter of 0.3-0.4mm ; The waste SCR catalyst is a particle with a particle size of 0.5-1 mm, and its components include V ₂ O ₅ , WO ₃ and TiO ₂ . The granular waste SCR catalyst is broken from the waste block waste SCR catalyst. The waste SCR catalyst refers to the SCR catalyst that has been replaced after the SCR catalyst has been used for a long time, its catalytic activity has decreased, and the denitrification effect cannot be achieved. That is, when the catalytic activity of the SCR catalyst drops to 80% of the original, it can be considered that the catalyst has been deactivated and becomes a waste SCR catalyst). The catalyst assembly 43 adopts a drawer type. The catalyst assembly 43 is connected to the inner wall of the waste SCR catalytic oxidation device 4. The waste SCR catalytic oxidation device 4 is provided with an opening that can be opened and closed for use with the catalyst assembly 43. The catalyst assembly 43 can be used from The opening is inserted or pulled out, and when the catalyst assembly 43 needs to be replaced, the present invention stops adding fly ash and ozone, and takes out the catalyst assembly 43 after opening the opening; the opening is in a closed state during normal operation, and gas will not leak out from the opening. The waste SCR catalytic oxidation device 4 is provided with an exhaust gas heating device 44 , which is a heating layer with a heating temperature of 90-200° C., which can assist catalytic oxidation of the exhaust gas in the waste SCR catalytic oxidation device 4 . The air outlet 42 of the waste SCR catalytic oxidation device 4 is provided with an induced draft fan 45, which can discharge the processed gas from the air outlet 42, and the gas space velocity in the catalyst assembly 43 of the waste gas SCR catalytic oxidation device 4 is controlled at 5000 ~10000/h.

The use process of the present invention is:

The fly ash is added into the fly ash quantitative feeder 12 through the ash hopper 11, and the fly ash is added to the fly ash catalytic oxidation device 3 through the fly ash inlet 31 controlled by the fly ash quantitative feeder 12; at the same time, the ozone generator 2 generates ozone, and the ozone Enter the fly ash catalytic oxidation device 3 from the gas inlet 32; the ratio of the amount of ozone and fly ash added is 0.1 to 0.5g ozone/kg fly ash;

Fly ash and ozone are stirred and mixed by the spiral blade 35 in the fly ash catalytic oxidation device 3 and simultaneously pushed to the gas outlet 33 and the fly ash outlet 34. During this process, the fly ash heating device 36 heats to assist catalytic oxidation (heating temperature is 50-90 °C), the gas space velocity in the waste SCR catalytic oxidation device 4 is 5000-10000/h. The dioxin-like organic substances contained in fly ash (mostly) are degraded into CO ₂ , H ₂ O and HCl, etc. by ozone catalytic oxidation, or decomposed into gaseous low-molecular-weight and low-toxic organic substances (there are also a small part of dioxins without Catalytic oxidation or decomposition, that is, the treatment efficiency of dioxin has not reached 100%.); the residence time of fly ash in the fly ash catalytic oxidation device 3 is greater than 1min, so that the dioxin in fly ash can be catalyzed and oxidized as much as possible. At this time, ozone is also converted into oxygen.

The fly ash processed by the fly ash catalytic oxidation device 3 enters the fly ash collection device 5 through the fly ash outlet 34, and then undergoes solidification and stabilization treatment to remove the heavy metal substances contained in the fly ash; the fly ash catalytic oxidation device 3 processes The final exhaust gas enters the waste SCR catalytic oxidation device 4 through the gas outlet 33 and the air inlet 41, and the exhaust gas heating device 44 assists in catalytic oxidation (the heating temperature is 90-200°C, and the catalytic activity of the catalyst assembly 43 is activated after exceeding 90°C. The degradation effect is ideal, so after the temperature of the waste SCR catalytic oxidation device 4 exceeds 90°C, no dioxin and other gaseous organic pollutants are detected in the gas outlet 42). Due to the catalytic oxidation assisted by the reaction temperature in the fly ash catalytic oxidation device 3, some dioxin-like organic substances are decomposed into gaseous low-molecular-weight and low-toxic organic substances, so the exhaust gas from the gas outlet 33 contains other gaseous organic substances. At this time, the gaseous organic substances are It is a gaseous low-molecular-weight and low-toxic organic substance. These gaseous organic substances enter the waste SCR catalytic oxidation device 4 along with the exhaust gas, and are catalyzed and oxidized by the catalyst layer of the catalyst assembly 43, and finally degraded into harmless CO ₂ and H ₂ O. It is discharged from the air outlet 42 under the action. After the spent SCR catalyst is further used for a period of time, its catalytic oxidation performance will decrease, and then the catalyst assembly 43 can be recycled or regenerated.

The regeneration of the catalyst assembly 43 is a conventional technique, including ultrasonic water washing with an organic polymer cleaning agent.

The curing and stabilization treatment can adopt conventional cement curing method, lime curing method or chemical stabilization method.

1. Cement curing method

The curing treatment is to use the curing agent to mix with the waste incineration fly ash to form a solidified body, thereby reducing the dissolution of heavy metals. Cement is the most common solidifying agent for hazardous waste, so cement is often used in engineering to solidify incineration fly ash. After the fly ash is mixed into the cement matrix, under certain conditions, after a series of physical and chemical actions, the mobility of pollutants in the waste cement matrix system is reduced (such as forming many metal oxides). Sometimes, some auxiliary materials are added to enhance the reaction process, and finally the granular material becomes a bonded concrete block. A large amount of waste is thus stabilized by solidification. The research results of the stabilization treatment of waste incineration fly ash show that no matter the fly ash pre-treatment processes such as washing and crushing are used, it is difficult for the blocks after treatment to achieve high strength. In addition, when studying the leaching of heavy metals in fly ash, it was found that due to the influence of chloride ions in fly ash, ions such as iron, copper, and zinc in solidified blocks were easily leached, resulting in excessive pollutants.

2. Lime solidification method

Lime solidification refers to the solidification or stabilization of hazardous waste using substances with Pozzolanic Reaction (Pozzolanic Re. Under a suitable catalytic environment, carry out the Posolite reaction, and absorb the heavy metal components in the waste into the colloidal crystals produced. The structural strength of lime solidified is not as good as that of cement solidified, so it is rarely used alone. In addition, there are asphalt curing, plastic material curing technology, self-cementing curing, large-scale rubber encapsulation, etc., but due to technical and economic limitations, they are rarely used in the treatment of domestic waste incineration fly ash.

3. Drug stabilization method

Chemical stabilization technology is mainly used to deal with heavy metal waste. At present, a variety of heavy metal stabilization technologies have been developed, such as pH control technology, oxidation, reduction potential control technology, precipitation technology, adsorption technology and ion exchange technology. This type of technology is currently less used in the stabilization of waste incineration fly ash, but it is a development direction. In particular, drug stabilization has the advantages of simple process, good stabilization effect, and low cost compared with other stabilization methods.

Experiment 1. The fly ash (with a dioxin content of about 150ng/g) taken from a waste incineration power plant was processed according to the method described in Example 1. The various process parameters were as follows: the feed rate of fly ash was 10g/min, ozone The addition amount is 0.3g/h, the reaction temperature of the fly ash catalytic oxidation device 3 is controlled at 90°C, and the residence time of the fly ash in the fly ash catalytic oxidation device 3 is about 2 minutes. The heating temperature of the waste SCR catalytic oxidation device 4 is 90°C, and the gas space velocity is 8000h ^-1 . The performance data of the fly ash and gas after treatment are: the dioxin content in the fly ash discharged from the fly ash outlet 34 of the fly ash catalytic oxidation device 3 is 20ng/g, and the dioxin removal rate reaches 87%; and the waste SCR No dioxin and other gaseous organic pollutants were detected in the gas discharged from the gas outlet 42 of the catalytic oxidation device 4 .

Comparative example 1, remove the ozone generator 2 in Experiment 1, that is, the reaction process does not pass through the ozone, but only passes through the air. The reaction process is carried out by thermal catalytic reaction; the rest is the same as Experiment 1.

The device was tested as in Experiment 1, and the performance data after processing were as follows: the dioxin content in the fly ash discharged from the fly ash outlet 34 of the fly ash catalytic oxidation device 3 was 92ng/g, and the dioxin removal rate was only 39%; but no dioxin was detected in the gas discharged from the gas outlet 42 of the waste SCR catalytic oxidation device 4 .

Comparative example 2. The discarded SCR catalytic oxidation device 4 in Experiment 1 was removed, and only the fly ash catalytic oxidation device 3 was used to treat incineration fly ash; the rest was the same as Experiment 1.

This device is tested as in Experiment 1, and the performance data after processing are: the dioxin content in the fly ash discharged from the fly ash outlet 34 of the fly ash catalytic oxidation device 3 is 20ng/g, and the dioxin removal rate is 87 %; Although no dioxin was detected in the gas discharged from the gas outlet 33, other gaseous organic pollutants were detected, with an approximate concentration of 30ng/g.

Comparative Example 3. Change the amount of ozone added in Experiment 1 to 0.1 and 0.5g/h respectively; the rest are the same as Experiment 1.

This device is detected as experiment 1, and the performance data after processing are: the dioxin content in the fly ash discharged from the fly ash outlet 34 of the fly ash catalytic oxidation device 3 is 65ng/g and 8ng/g, and the dioxin The removal rates were 57% and 95%, and no dioxin and other gaseous organic pollutants were detected in the gas discharged from the gas outlet 42 of the waste SCR catalytic oxidation device 4 . This shows that the addition of ozone has an important impact on the removal of dioxins. With the increase of the amount of ozone added, the removal effect of dioxins increases. But because ozone itself is also a pollutant, too much ozone is likely to cause secondary pollution, so the amount of ozone added should be controlled at 0.1-0.5ng/g (fly ash).

Comparative Example 4. The heating temperature of the fly ash catalytic oxidation device 3 in Experiment 1 was changed to 50°C and 150°C respectively. The rest are the same as Experiment 1.

This device is detected as Experiment 1, and the performance data after processing are: the dioxin content in the fly ash discharged from the fly ash outlet 34 of the fly ash catalytic oxidation device 3 is 38ng/g and 56ng/g, and the dioxin content is 56ng/g. The removal rates were 75% and 63%, but no dioxin and other gaseous organic pollutants were detected in the gas discharged from the gas outlet 42 of the waste SCR catalytic oxidation device 4 . This shows that the reaction temperature of the fly ash catalytic oxidation device 3 has an impact on the removal of dioxins. The heating temperature of about 90°C in Experiment 1 is the most suitable. The lower the temperature, the lower the catalytic activity, and the higher the temperature, the lower the activity of ozone. .

Comparative Example 5. Change the heating temperature of the waste SCR catalytic oxidation device 4 in Experiment 1 to 50°C and 150°C respectively, and the rest are the same as Experiment 1.

The device was tested as in Experiment 1, and the performance data after treatment were as follows: the dioxin content in the fly ash discharged from the fly ash outlet 34 of the fly ash catalytic oxidation device 3 was 20ng/g, and the dioxin removal rate was 20ng/g. 87%; at 50°C, no dioxin was detected in the gas discharged from the gas outlet 42 of the discarded SCR catalytic oxidation device 4, but other gaseous organic pollutants were detected, about 20ng/g; discarded at 150°C No dioxin and other gaseous organic pollutants were detected in the gas discharged from the gas outlet 42 of the SCR catalytic oxidation device 4 .

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the embodiments of the invention.

Claims (10)

1. domestic garbage incineration flyash and discarded SCR catalyst coprocessing system, it is characterised in that：Including flying dust feed arrangement (1), ozone generating-device (2), flying dust catalytic oxidizing equipment (3), discarded SCR catalytic oxidizing equipments (4) and ash collecting device (5)；Gas feed (32), flying dust import (31), gas vent (33) are provided with the flying dust catalytic oxidizing equipment (3) and is flown Ash outlet (34)；Air inlet (41) and gas outlet (42) are provided with the discarded SCR catalytic oxidizing equipments (4)；The gas Import (32) is connected with ozone generating-device (2), gas vent (33) and the air inlet of discarded SCR catalytic oxidizing equipments (4) (41) connect, flying dust outlet (34) is connected with ash collecting device (5)；

Helical blade (35) and flying dust heater (36) are respectively arranged with flying dust catalytic oxidizing equipment (3) inner chamber；

The flying dust feed arrangement (1) includes ash bucket (11) and the flying dust measured quantity dispensing device connected with the discharging opening of ash bucket (11) (12)；The flying dust measured quantity dispensing device (12) connects with flying dust import (31)；

Be provided with least one catalyst assembly (43) in the discarded SCR catalytic oxidizing equipments (4), catalyst assembly (43) with The inwall connection of discarded SCR catalytic oxidizing equipments (4)；Waste gas is provided with discarded SCR catalytic oxidizing equipments (4) inner chamber to add Thermal (44).

2. domestic garbage incineration flyash according to claim 1 and discarded SCR catalyst coprocessing system, its feature exist In：Air-introduced machine (45) is provided with the gas outlet (42) of the discarded SCR catalytic oxidizing equipments (4).

3. domestic garbage incineration flyash according to claim 2 and discarded SCR catalyst coprocessing system, its feature exist In：Be provided with the discarded SCR catalytic oxidizing equipments (4) with catalyst assembly (43) use cooperatively can open and close open Mouthful, catalyst assembly (43) is inserted or pull out from opening.

4. domestic garbage incineration flyash according to claim 3 and discarded SCR catalyst coprocessing system, its feature exist In：The catalyst assembly (43) is by discarding the catalyst layer and be arranged on the porous of catalyst layer both sides that SCR catalyst is constituted Stainless steel plate is constituted, and catalyst layer thickness is 5~10mm, and the aperture of porous stainless steel plate is 0.3~0.4mm；Discarded SCR catalysis Agent is 0.5~1mm of particle diameter particle.

5. the domestic garbage incineration flyash and discarded SCR that are carried out using the processing system as described in Claims 1 to 4 is any are catalyzed Agent cooperative processing method, it is characterised in that comprise the following steps：

Flying dust is added in flying dust measured quantity dispensing device (12) by ash bucket (11), and flying dust measured quantity dispensing device (12) passes through flying dust import (31) flying dust is added to flying dust catalytic oxidizing equipment (3)；Meanwhile, ozone generating-device (2) produces ozone, and ozone is from gas feed (32) flying dust catalytic oxidizing equipment (3) is entered；

Flying dust and ozone are simultaneously slow to gas vent by helical blade (35) stirring mixing in flying dust catalytic oxidizing equipment (3) (33) moved with flying dust outlet (34), contained dioxin organic matters are dropped by catalytic ozonation in flying dust in the process Solution is into CO₂、H₂O and HCl, or it is decomposed into gaseous low molecule amount low toxicity organic matter；

Flying dust after flying dust catalytic oxidizing equipment (3) processing exports (34) by flying dust and enters ash collecting device (5), and flying dust is urged Change the waste gas after oxidation unit (3) processing and discarded SCR catalytic oxidizing equipments are entered through air inlet (41) by gas vent (33) (4), the gaseous organic substance in waste gas is in discarded SCR catalytic oxidizing equipments (4), by catalyst layer catalysed oxidn, most Harmless CO is degraded to afterwards₂And H₂O, the clean gas after processing is discharged in the presence of air-introduced machine (45) from gas outlet (42).

6. domestic garbage incineration flyash according to claim 5 and discarded SCR catalyst cooperative processing method, its feature exist In：Carried out again at solidification and stabilization after flying dust in ash collecting device (5) after flying dust catalytic oxidizing equipment (3) processing Reason, so as to remove heavy metal classes material contained in the flying dust after processing.

7. domestic garbage incineration flyash and discarded SCR catalyst cooperative processing method according to claim 5 or 6, it is special Levy and be：Residence time of the flying dust in flying dust catalytic oxidizing equipment (3) is more than smelly in 1min, flying dust catalytic oxidizing equipment (3) The addition ratio of oxygen and flying dust is 0.1~0.5g ozone/kg flying dusts.

8. domestic garbage incineration flyash according to claim 7 and discarded SCR catalyst cooperative processing method, its feature exist In：Flying dust heater (36) is used to heat the flying dust and ozone in flying dust catalytic oxidizing equipment (3), and heating-up temperature is 50~90 ℃。

9. domestic garbage incineration flyash according to claim 8 and discarded SCR catalyst cooperative processing method, its feature exist In：Waste gas heater (44) is used to heat the waste gas in discarded SCR catalytic oxidizing equipments (4), and heating-up temperature is 90~200 DEG C, it is 5000~10000/h to discard gas space velocity in SCR catalytic oxidizing equipments (4).

10. domestic garbage incineration flyash according to claim 9 and discarded SCR catalyst cooperative processing method, its feature It is：Solidification and stabilization is processed as cement solidification method, lime solidification or chemical stabilization method.