CN107051033A - A kind of organic waste gas treatment system and processing method - Google Patents

Abstract

The invention discloses a treatment system and method for organic waste gas, which comprises a dust collector, an adsorber, a burner and an oxygen source. The attached outlet is connected to the inlet of the burner, the outlet of the burner is connected to the desorption inlet of the adsorber, and the oxygen source is connected to the inlet of the burner; wherein, the burner is sequentially provided with a mixing chamber, a gas uniform distributor and a combustion chamber from bottom to top The mixing chamber is provided with an organic waste gas pipeline and an oxygen pipeline; the combustion chamber is filled with a non-uniform honeycomb structure, and the non-uniform honeycomb structure includes a lower layer, a middle layer and an upper layer, wherein the middle layer is a combustion zone, and the apertures of the lower layer and the upper layer Smaller than the pore size of the middle layer; from bottom to top, the pore size and porosity of the middle layer increase. It can solve the problems of high equipment requirements, easy secondary pollution, low heat utilization rate of combustion flue gas and the like existing in the organic waste gas treatment method in the prior art.

Description

A kind of organic waste gas treatment system and treatment method

technical field

The invention belongs to the field of organic waste gas pollution control, and in particular relates to an organic waste gas treatment system and treatment method.

Background technique

At present, the methods for treating industrial organic waste gas at home and abroad mainly include adsorption method, combustion method and biological purification method; the adsorption method is suitable for the treatment of organic waste gas with large discharge volume and low concentration, and the combustion method is suitable for the treatment of organic waste gas with high concentration and no recovery value , The biological purification method is suitable for the treatment of low-concentration and toxic organic waste gas. In the actual industrial organic waste gas treatment, it is necessary to use a combination of various technologies to improve the efficiency of waste gas treatment according to the characteristics of different organic waste gases. For low-concentration, high-volume, and non-recyclable organic waste gas produced in petrochemical, coating, printing, packaging and other industries, it is usually treated by adsorption concentration combustion method.

The traditional adsorption concentration combustion method uses the high-temperature flue gas after combustion to heat the cold air through a heat exchanger, and the temperature of the cold air rises after absorbing heat, which is used for desorption and regeneration of activated carbon; Rust, corrosion, and desorbed organic waste gas spontaneously ignites, posing safety hazards. In addition, in the combustion process, there are mainly high-temperature incineration method and catalytic combustion method; high-temperature incineration method requires high quality equipment due to high combustion temperature, and it is easy to generate NO _x at high temperature, which is easy to cause secondary pollution. Although the catalytic combustion method has a low combustion temperature, the equipment is complicated, and impurities often appear in the organic waste gas, and the catalyst is easily poisoned and sintered, which increases the operating cost. In addition, the large amount of CO ₂ gas produced by the combustion method will also cause the greenhouse effect.

To sum up, the organic waste gas treatment methods in the prior art have problems such as high equipment requirements, easy to produce secondary pollution, and low heat utilization rate of combustion flue gas, and there is still no effective solution.

Contents of the invention

In view of the above-mentioned problems existing in the prior art, the object of the present invention is to provide an organic waste gas treatment system and treatment method. The organic waste gas treatment system can process medium and low concentration organic waste gas, and has a large range of processing air volume and high processing efficiency. Stable performance, no secondary pollution, simple equipment, energy saving and environmental protection.

To achieve the above object, the technical solution provided by the invention is:

An organic waste gas treatment system, including a dust collector, an adsorber, a burner and an oxygen source, the inlet of the dust remover is connected to the source of organic waste gas, the outlet of the dust remover is connected to the adsorption inlet of the adsorber, and the desorption outlet of the adsorber is connected to the inlet of the burner , the outlet of the burner is connected to the desorption inlet of the adsorber, and the oxygen source is connected to the inlet of the burner;

Wherein, the burner is sequentially provided with a mixing chamber, a gas uniform distributor and a combustion chamber from bottom to top; the mixing chamber is provided with an organic waste gas pipeline and an oxygen pipeline;

The combustion chamber is filled with a heterogeneous honeycomb structure porous medium, and the heterogeneous honeycomb structure porous medium includes a lower layer, a middle layer and an upper layer, wherein the middle layer is a combustion zone, and the apertures of the lower layer and the upper layer are smaller than the apertures of the middle layer; from bottom to top, The pore size and porosity of the middle layer increase;

A heating wire igniter is arranged at the junction of the lower layer and the middle layer.

The organic waste gas after adsorption and enrichment is mixed with CO ₂ for desorption and then passed into the burner for combustion. It shortens the burning time, speeds up the combustion speed, improves the efficiency and safety of organic waste gas treatment, reduces the generation of nitrogen oxides, and avoids secondary pollution.

The small-diameter porous medium placed on the gas uniform distributor in the burner absorbs the heat from the combustion zone for heat storage, preheats the mixed gas, and at the same time transfers part of the heat to the outside through the gas uniform distributor with good thermal conductivity. Prevent the occurrence of flashback; the small-pore porous media placed at the outlet of the burner can prevent the flame from drifting to the outside world. The middle section adopts a large-diameter porous medium with increasing porosity and pore diameter, so that the volatile organic compounds of different components in the mixed gas can be stably burned and decomposed at different positions of the porous medium material. The burner reduces the volume of the equipment, has a large load adjustment range, further reduces secondary pollution, improves the combustion rate, and makes the combustion of organic waste gas safer and more stable.

Due to the existence of porous media materials, the heat generated by the combustion of organic waste gas can be quickly transferred out, the peak temperature of combustion can be reduced, the temperature distribution near the combustion flame surface can be uniform, and the generation of NO _X can be reduced; through the heat storage function of the porous media itself, it can be predicted Heat organic waste gas, improve combustion efficiency, and recover high-temperature flue gas waste heat, which is used for desorption of zeolite molecular sieve runner; organic waste gas has turbulence effect in the pores of porous media, strengthens the mixing and dispersion effect of gas, and improves the combustion and decomposition of organic waste gas Speed; the porous media burner has a large load adjustment range, which can effectively adapt to the fluctuation of the concentration of organic waste gas components, and prevent flame fluctuations or even flameout.

The combustion hot air in the burner enters the adsorber for desorption. Since the hot air has a high temperature, no heat exchanger is needed, which reduces the volume of the equipment and improves the heat utilization rate of the system. At the same time, the main component in the hot air is carbon dioxide and does not contain oxygen. When hot air is used as the desorption medium, no oxygen is introduced during the desorption process, which avoids safety hazards such as equipment oxidation, adsorption material ignition, and organic waste gas spontaneous combustion.

Further, the dust collector is a bag filter. The bag filter can remove the particles and viscous components in the exhaust gas, prevent the surface of the adsorption material from clogging, prolong the service life of the adsorption material, and then adsorb it in the adsorber, and the purified gas is emptied through the induced draft fan.

Further, the adsorber is a zeolite molecular sieve wheel. The adsorber can realize desorption and adsorption processes simultaneously, and realizes continuous work.

Further, the combustion chamber is provided with at least two secondary oxygen pipes, one end of the secondary oxygen pipe is inserted at different heights in the middle layer of the non-uniform honeycomb structure through the casing of the combustion chamber, and the other end extends out of the casing of the combustion chamber Connect to oxygen source.

The secondary oxygen pipe is inserted into different heights of the porous medium in the middle layer, and the step-by-step oxygen supply is adopted for step-by-step mixing. The unburned organic waste gas is mixed with the secondary oxygen step by step to form a step-by-step combustion, which is conducive to enhancing gas disturbance. The axial distance of combustion is lengthened, the combustion space is expanded, and the combustion temperature of the combustion chamber is controlled, thereby enhancing combustion stability and combustion efficiency.

Furthermore, the oxygen source is an air separator, and the oxygen outlet of the air separator is connected with the air inlet of the burner and the secondary oxygen pipe.

The air separator can separate the oxygen in the air to provide oxygen for the combustion in the combustion chamber.

Furthermore, the nitrogen outlet of the air separator is connected with the nitrogen cylinder. At the same time, the air separator can prepare relatively pure nitrogen, and the nitrogen can be collected by the nitrogen bottle, which can be used in places such as transportation protective gas and reaction protective gas.

Further, the organic waste gas treatment system further includes a condenser, the condenser is connected to the outlet of the burner, and the gas outlet of the condenser is connected to the CO ₂ compressor.

The combustion hot air of the burner contains a lot of water, the condenser can cool part of the combustion hot air, the moisture in the hot air is condensed into condensed water, and the condensed water is discharged or recovered; the carbon dioxide obtained after condensation can be compressed by a _CO2 compressor For storage, the collected carbon dioxide can be used in other production sites, avoiding the pollution of the environment caused by the emission of carbon dioxide.

Further, the inlet end of the burner is connected with a first flame arrester, and the outlet end is connected with a second flame arrester. Flame arresters can prevent external flames from escaping into the pipeline and prevent flames from spreading between equipment and pipelines.

Further, a mixing chamber is connected between the first flame arrester and the adsorber, and the oxygen source is connected to the mixing chamber.

Organic gas and oxygen are mixed in the mixing chamber, which is more conducive to subsequent combustion.

Further, from bottom to top, the average pore diameter of the middle layer of the heterogeneous honeycomb structure varies from 2.5 to 5mm, and the porosity varies from 80 to 90%.

Further, the pore diameter of the upper layer and the lower layer of the heterogeneous honeycomb structure is 0.5-1mm, and the porosity is 70-80%.

The burner with this structure can enhance the combustion stability and combustion efficiency of organic waste gas, and enhance the combustion adaptability to fluctuations in the composition and concentration of organic waste gas.

Further, the mixing chamber is filled with alumina pellets, so that the organic waste gas and oxygen generate turbulence in the pores of the alumina pellets, so that they are fully mixed, and at the same time, the desorbed organic waste gas and _CO have a certain temperature. The thermal storage characteristics of alumina pellets can make the temperature of oxygen and organic waste gas uniform.

Furthermore, the particle size of the alumina pellets is between 10-30mm, and the formed porosity ranges between 30%-50%.

Further, the inner diameter of the mixing chamber increases from bottom to top. The flow rate of the mixed gas can be reduced, which is beneficial to improve the stability of the combustion of the organic waste gas.

The installation of oxygen pipelines and secondary oxygen pipes is beneficial to reduce the ignition point of organic waste gas, promote ignition and combustion, increase gas disturbance in the later stage of combustion, control the temperature distribution in the combustion chamber, enhance the burner load adjustment range, and reduce the formation of nitrogen oxides. Improve the combustion efficiency and combustion stability of organic waste gas.

Furthermore, gas flow regulating valves are respectively set on the oxygen pipeline and the secondary oxygen pipeline, and by adjusting the flow ratio of the primary oxygen and the secondary oxygen, the length of the combustion flame can be changed and the combustion stability can be controlled.

A method for treating organic waste gas, comprising the steps of:

The organic waste gas enters the dust collector and enters the adsorber for adsorption after dust removal. The purified gas is discharged. After the adsorber is saturated, the desorption medium is passed into the adsorber for desorption; the mixed gas obtained by desorption is mixed with oxygen and passed through Part of the hot air obtained by combustion is passed into the adsorber as an adsorption medium for desorption, and the other hot air enters the condenser to condense, the water obtained by condensation is recovered, and the carbon dioxide obtained by condensation is compressed and stored.

Further, in this treatment method, an induced draft fan is used to provide power.

The beneficial effects of the present invention are:

1) Introducing oxygen-enriched combustion technology into the treatment of organic waste gas can reduce the ignition point of organic waste gas, reduce the burning time, speed up the combustion speed, improve the efficiency and safety of organic waste gas treatment, reduce the generation of NOx, and prevent secondary pollution .

2) The burner adopts a porous medium burner, which reduces the volume of the equipment, has a large load adjustment range, reduces secondary pollution, improves the combustion rate, widens the combustion high temperature area, and makes the combustion of organic waste gas safer and more stable.

3) Using part of the flue gas generated by oxygen-enriched combustion to desorb the zeolite molecular sieve runner, the equipment is simple and the heat utilization rate is high, which avoids safety hazards such as equipment oxidation, adsorption material ignition and organic waste gas spontaneous combustion.

4) Condensing and compressing the flue gas produced by oxygen-enriched combustion to separate high-purity CO ₂ and capture CO ₂ , which has environmental protection significance.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application, and do not constitute improper limitations to the present application.

Fig. 1 is a schematic structural diagram of the organic waste gas treatment system of the present invention.

Among them, 1. Bag filter, 2. Adsorber, 3. Induced fan, 4. Desorption fan, 5. Flow regulating valve Ⅰ, 6 Mixing chamber, 7. The first flame arrester, 8. Burner, 9. Second flame arrester, 10. Condenser, 11. _CO2 compressor, 12. _CO2 storage tank, 13. Air separator, 14. Flow regulating valve Ⅱ, 15. Gas cylinder, 16. Flow regulating valve Ⅲ, 17 .Flow regulating valve Ⅳ.

detailed description

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

As shown in Figure 1, an organic waste gas treatment system and treatment method, the treatment method mainly includes the organic waste gas adsorption process, the _CO2 recycling desorption process, the organic waste gas oxygen-enriched combustion process, and the _CO2 recovery process; the device includes a bag filter 1, adsorption/desorption device 2, flame arrester 7, burner 8, air separator 13, condenser 10, CO ₂ compressor 11, CO ₂ storage tank 12.

The organic waste gas treatment method refers to that the organic waste gas is dedusted through the bag filter 1 , and then passed into the adsorber 2 for adsorption, and the purified gas is evacuated through the induced draft fan 3 . After the organic waste gas is adsorbed and saturated, the high-temperature _CO2 gas after combustion is partially introduced into the adsorber 2 through the flame arrester II9 for desorption operation, and the desorbed and concentrated organic waste gas and _CO2 gas pass through the desorption fan 4 together Enter the intake pipe of the burner 8, and set the gas flow regulating valve I5 in the intake pipe to adjust the flow of the mixed gas, and then pass it into the gas mixing chamber 6. Separation of high-purity _O2 and _N2 by air separator 13, high-purity _N2 can be used as transport protection gas or compressed gas cylinder 15 for industrial sale, high-purity _O2 leads to another intake pipe of burner 8 In the middle of the pipeline, a gas flow regulating valve II14 is set in the middle of the pipeline to regulate the flow, and then pass into the mixing chamber 6. After O ₂ is fully mixed with CO ₂ and organic waste gas, it passes through the first flame arrester 7 and then enters the burner 8. At the same time, the flow regulating valves 16 and 17 are adjusted to supply oxygen step by step and mix with the organic waste gas step by step. A gradual oxygen-enriched combustion is formed. Part of the combusted flue gas is introduced into the adsorber 2 for desorption after passing through the second flame arrester 9, and part of the flue gas is passed into the condenser 10 for gas-liquid separation, and the condensed water is discharged through the pipeline to obtain pure _CO2 . Go to the CO ₂ compressor 11 for compression, and the obtained CO ₂ liquid is passed into the CO ₂ storage tank 12 for sequestration.

The adsorber 2 is selected to use a zeolite molecular sieve runner, which can realize desorption and adsorption processes simultaneously and work continuously.

The burner 8 is a porous media burner, and a first flame arrester 7 and a second flame arrester 9 are respectively installed at the inlet end of the burner and the flue gas outlet end. The burner is provided with a mixing chamber, a gas uniform distributor and a combustion chamber in sequence from bottom to top; the mixing chamber is provided with an organic waste gas pipeline and an oxygen pipeline, and the mixing chamber is filled with alumina pellets; the combustion chamber is filled with a non-uniform honeycomb structure , the non-uniform honeycomb structure includes a lower layer, a middle layer and an upper layer, wherein the middle layer is the combustion zone, and the apertures of the lower layer and the upper layer are smaller than that of the middle layer; from bottom to top, the aperture and porosity of the middle layer increase; the junction of the lower layer and the middle layer is set There is a heating wire igniter.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (10)

1. An organic waste gas treatment system, characterized in that: it comprises a dust remover, an adsorber, a burner and an oxygen source, the inlet of the dust remover is connected to the organic waste gas source, the outlet of the dust remover is connected to the adsorption inlet of the adsorber, and the adsorber desorbs The outlet is connected to the inlet of the burner, the outlet of the burner is connected to the desorption inlet of the adsorber, and the oxygen source is connected to the inlet of the burner; Wherein, the burner is sequentially provided with a mixing chamber, a gas uniform distributor and a combustion chamber from bottom to top; the mixing chamber is provided with an organic waste gas pipeline and an oxygen pipeline; The combustion chamber is filled with a heterogeneous honeycomb structure porous medium, and the heterogeneous honeycomb structure porous medium includes a lower layer, a middle layer and an upper layer, wherein the middle layer is a combustion zone, and the apertures of the lower layer and the upper layer are smaller than the apertures of the middle layer; from bottom to top, The pore size and porosity of the middle layer increase; A heating wire igniter is arranged at the junction of the lower layer and the middle layer. 2. The organic waste gas treatment system according to claim 1, characterized in that: the adsorber is a zeolite molecular sieve runner. 3. The organic waste gas treatment system according to claim 1, characterized in that: at least two secondary oxygen pipes are arranged in the combustion chamber, and one end of the secondary oxygen pipe is inserted into the non-uniform honeycomb structure through the casing of the combustion chamber At different heights in the middle layer, the other end extends out of the shell of the combustion chamber. 4. The organic waste gas treatment system according to claim 3, wherein the oxygen source is an air separator, and the oxygen outlet of the air separator is connected to the inlet of the burner. 5. The organic waste gas treatment system according to claim 1, characterized in that: the organic waste gas treatment system further comprises a condenser, the condenser is connected to the outlet of the burner, and the gas outlet of the condenser is connected to the storage tank. 6. The organic waste gas treatment system according to claim 1, characterized in that: the inlet end of the burner is connected with a first flame arrester, and the outlet end is connected with a second flame arrester. 7. The organic waste gas treatment system according to claim 6, wherein a mixing chamber is connected between the first flame arrester and the adsorber, and the oxygen source is connected to the mixing chamber. 8. The organic waste gas treatment system according to claim 1, characterized in that: from bottom to top, the average pore diameter of the middle layer of the heterogeneous honeycomb structure porous medium varies from 2.5 mm to 5 mm, and the range of porosity varies from 80 mm to 90%. 9. The organic waste gas treatment system according to claim 1, characterized in that: the pore diameter of the upper layer and the lower layer of the heterogeneous honeycomb structure porous medium is 0.5-1mm, and the porosity is 70-80%. 10. A treatment method for organic waste gas, characterized in that: comprising the steps of: The organic waste gas enters the dust collector and enters the adsorber for adsorption after dust removal. The purified gas is discharged. After the adsorber is saturated, the desorption medium is passed into the adsorber for desorption; the mixed gas obtained by desorption is mixed with oxygen and passed through Part of the hot air obtained by combustion is passed into the adsorber as an adsorption medium for desorption, and the other hot air enters the condenser to condense, the water obtained by condensation is recovered, and the carbon dioxide obtained by condensation is compressed and stored.