An adsorption treatment system for organic waste gas containing polar components

Abstract

The present invention relates to an adsorption treatment system for organic waste gas containing polar components, which comprises: a non-polar component adsorption bed, a water vapor adsorption bed and a polar component adsorption bed; wherein, the non-polar component adsorption bed is filled with granular or honeycomb activated carbon; the water vapor adsorption bed is filled with spherical molecular sieves; the polar component adsorption bed is filled with ZSM molecular sieves modified with nickel or molybdenum metals; the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are arranged in sequence according to the flow direction of the organic waste gas, so that the non-polar components in the organic waste gas are first adsorbed and fixed by the non-polar component adsorption bed, then hygroscopically dried by the water vapor adsorption bed, and finally the polar components in the organic waste gas are adsorbed and fixed by the polar component adsorption bed. When the adsorption treatment system provided by the present invention is used to treat organic waste gas containing polar components with a large air volume and low concentration, it can achieve efficient and stable adsorption of polar small molecular substances and meet emission standards.

Description

Technical Field

[0001] The invention relates to the technical field of industrial waste gas treatment, and in particular to an adsorption treatment system and method for organic waste gas containing polar components. Background Art

[0002] A large amount of organic waste gas emitted in industrial production is the precursor of PM2.5 and O3. The aerosol generated by its photochemical reaction is also an important component of PM10. The existence of volatile organic compounds (VOCs) seriously affects human health and environmental pollution. Countries have successively promulgated relevant laws on air pollution prevention and control to control VOCs emissions. Various parts of my country have also formulated strict emission restriction measures. VOCs prevention and control has received widespread attention from all walks of life, and treatment methods have also been continuously studied and practiced. Widely used VOCs treatment terminal technologies include destruction technology and recovery technology. For the treatment of large air volume and low concentration VOCs, whether it is destruction technology or recovery technology, adsorption and concentration are the key pretreatment processes. Among them, the adsorption and concentration effect is the key to determining whether the technology can be successfully applied. The adsorption method is a method of separating and enriching VOCs from the gas phase using adsorption materials with a large specific surface area. The adsorption performance of the adsorbent is the core of the adsorption technology. Activated carbon is widely available, low cost, has a rich multi-level pore structure and a large specific surface area, and has a good adsorption effect on most VOCs such as benzene, esters and ketones. It is currently a commonly used adsorption material in industry.

[0003] However, when polar components such as methanol and methyl chloride exist in the organic waste gas, the non-polar surface of activated carbon has a weak ability to adsorb polar molecules, so it can only be used in small air volume occasions. It is difficult to achieve standard emissions for large air volume and low concentration of organic waste gas containing polar components. For this reason, relevant researchers have proposed some solutions. For example, Zhang Ming and others proposed a utility model patent scheme CN205613245U, which involves a chemical organic waste gas treatment device, which uses activated carbon as an adsorbent, but can only be used in small air volume locations such as the breathing valve on the top of the storage tank. Wang Fengwei and others proposed a utility model patent scheme CN208449008U, which involves a combined organic waste gas purification and recovery device, which uses a combination of spray washing, biological purification, activated carbon adsorption and photocatalysis to remove short-chain polar organic molecules. It involves many processes, and the process and control are too complicated. In 2021, Gao Xiaoyang et al. filed an invention patent application CN202111471440.1, which involves a polar organic waste gas adsorbent, and uses a modified silicon-aluminum molecular sieve to solve the adsorption problem of polar small molecules. However, when polar components, non-polar components and water vapor coexist in organic waste gas, the non-polar components and water vapor will have an adverse effect on the polar component adsorbent, resulting in the system's unsatisfactory adsorption of polar small molecules. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an adsorption treatment system for organic waste gas containing polar components, which is a reasonable adsorption treatment system specially established for organic waste gas containing polar components with large air volume and low concentration. When treating organic waste gas containing polar components with large air volume and low concentration, it can achieve efficient and stable adsorption of polar small molecular substances and meet emission standards.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, the present invention provides an adsorption treatment system for organic waste gas containing polar components, comprising: a non-polar component adsorption bed, a water vapor adsorption bed and a polar component adsorption bed; wherein the non-polar component adsorption bed is filled with granular or honeycomb activated carbon; the water vapor adsorption bed is filled with spherical molecular sieves; and the polar component adsorption bed is filled with ZSM molecular sieves modified with nickel or molybdenum metals;

[0009] The non-polar component adsorption bed, water vapor adsorption bed and polar component adsorption bed are arranged in sequence according to the flow direction of the organic waste gas, so that the non-polar components in the organic waste gas are first adsorbed and fixed by the non-polar component adsorption bed, and then absorbed and dried by the water vapor adsorption bed, and finally the polar components in the organic waste gas are adsorbed and fixed by the polar component adsorption bed.

[0010] According to a preferred embodiment of the present invention, the spherical molecular sieve in the water vapor adsorption bed is one of spherical 3A, 4A, 5A, and 13X molecular sieves; the ZSM series molecular sieve in the polar component adsorption bed is any one of ZSM-4, ZSM-5, ZSM-12 and ZSM-20.

[0011] Experiments have found that nickel or molybdenum modified ZSM molecular sieves have a particularly significant adsorption effect on polar small molecular organic matter, such as methanol, with an adsorption rate of at least 99.0%.

[0012] According to a preferred embodiment of the present invention, the modification method of the nickel or molybdenum metal-modified ZSM molecular sieve includes an impregnation method and a solid phase method; the impregnation method is to impregnate the ZSM molecular sieve into a nickel or molybdenum water-soluble salt, then separate the molecular sieve, and perform oxygen roasting to obtain the nickel or molybdenum metal-modified ZSM molecular sieve; the solid phase method is to ball-mill the nickel or molybdenum oxide or metal salt, and then mix and roast it with the molecular sieve to obtain the nickel or molybdenum metal-modified ZSM molecular sieve. The molybdenum water-soluble salt can use ammonium molybdate, and the nickel water-soluble salt can use nickel acetate, nickel chloride, nickel nitrate, etc.

[0013] According to a preferred embodiment of the present invention, the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are respectively provided with a first end and a second end; the first end of the non-polar component adsorption bed is connected to the organic waste gas, and the second end is connected to the first end of the water vapor adsorption bed; the second end of the water vapor adsorption bed is connected to the first end of the polar component adsorption bed; the second end of the polar component adsorption bed is connected to a fan, and the fan is connected to a chimney.

[0014] According to a preferred embodiment of the present invention, a first adsorption air inlet valve is provided at the first end of the non-polar component adsorption bed, and organic waste gas is connected through the first adsorption air inlet valve; at least one connecting valve is provided between the second end of the non-polar component adsorption bed and the first end of the water vapor adsorption bed; at least one connecting valve is provided between the second end of the water vapor adsorption bed and the first end of the polar component adsorption bed; and at least one connecting valve is provided between the second end of the polar component adsorption bed and the fan.

[0015] According to a preferred embodiment of the present invention, the first end of the non-polar component adsorption bed is provided with a first adsorption air inlet valve, and the second end is provided with a first adsorption air outlet valve; the first end of the water vapor adsorption bed is provided with a second adsorption air inlet valve, and the second end is provided with a second adsorption air outlet valve; the first end of the polar component adsorption bed is provided with a third adsorption air inlet valve, and the second end is provided with a third adsorption air outlet valve; the first end of the non-polar component adsorption bed is connected to the organic waste gas through the first adsorption air inlet valve, and the second end is connected to the first end of the water vapor adsorption bed through the first adsorption air outlet valve and the second adsorption air inlet valve; the second end of the water vapor adsorption bed is connected to the first end of the polar component adsorption bed through the second adsorption air outlet valve and the third adsorption air inlet valve; the second end of the polar component adsorption bed is connected to the fan through the third adsorption air outlet valve.

[0016] According to a preferred embodiment of the present invention, the flow space velocity of the organic waste gas in the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed is 5000-10000h -1 .

[0017] According to a preferred embodiment of the present invention, the adsorption treatment system also includes a desorption system; the desorption system includes a desorption medium supply end and a desorption gas treatment end; the adsorption medium supply end is connected to one end (preferably but not limited to the second end) of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed through pipelines and independent control valves, respectively, and the desorption gas treatment end is connected to the other end (preferably but not limited to the first end) of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed through pipelines and independent control valves, respectively.

[0018] According to a preferred embodiment of the present invention, the desorption gas processing end is connected to a burner, which combines the waste gas eluted from the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed for combustion treatment and produces tail gas; the desorption medium supply end is connected to the tail gas discharge port of the burner to obtain an elution medium with a certain initial temperature (combustion tail gas of 250-280°C), and the desorption medium supply end is also connected to a nitrogen gas source; the combustion tail gas and nitrogen gas source connected to the desorption medium supply end can be switched.

[0019] Preferably, the flow space velocity of the combustion tail gas / nitrogen in the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed is 500-1000h -1 .

[0020] According to a preferred embodiment of the present invention, the desorption medium supply end is connected to a main pipeline, and a flame arrester is provided on the main pipeline near the desorption medium supply end; the main pipeline is connected to the second ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed respectively through a plurality of branch pipes and independent control valves provided on each branch pipe; wherein a cooler is provided on the branch pipe connected to the non-polar component adsorption bed. Preferably, the cooler is an air cooler, which cools the combustion exhaust gas at 250-280°C to 80-120°C, so as to avoid the excessive temperature of the non-polar component adsorption bed, which may cause oxidation or even combustion of the activated carbon loaded therein.

[0021] According to a preferred embodiment of the present invention, the chimney and the desorption gas processing end are both provided with a gas composition detector; the gas composition detector is connected to a control center, and the control center signals control the adsorption inlet valves and the adsorption outlet valves connected to both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed, as well as the valves of the desorption system;

[0022] When the adsorption treatment system starts working, the control center controls the adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed to be connected, and the valves of the desorption system are closed; at this time, the organic waste gas flows through the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed in sequence, and the tail gas enters the chimney; when the gas composition detector installed in the chimney monitors that the tail gas does not meet the standard, it means that at least one of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed is saturated and needs to be desorbed. At this time, the control center controls The adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are closed, and the valves of the desorption system are connected. The desorption medium supply end supplies gas with a relatively high initial temperature to the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed for elution treatment. The eluted gas enters the burner of the desorption gas treatment end for combustion and generates combustion tail gas. When the gas component detector in the desorption gas treatment end detects that the VOC concentration is lower than the preset value (such as the VOC concentration is less than 50 mg / m 3 ), indicating that the elution of each adsorption bed is completed. At this time, the control center controls the desorption medium supply end to switch to a nitrogen gas source, and uses the nitrogen gas source to purge and cool the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed to room temperature. Then, the valves of the desorption system are controlled to be closed, and at the same time, the adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are connected, and the organic waste gas adsorption treatment is carried out again.

[0023] According to a preferred embodiment of the present invention, the non-polar component adsorption bed, water vapor adsorption bed and polar component adsorption bed are also provided with temperature control devices respectively to ensure that the organic waste gas (non-polar component, water and polar component) is at the most favorable adsorption temperature during the adsorption process, preferably 30-50°C.

[0024] Among them, the control center can not only control the connection or closing state of each valve, but also adjust the valve opening and the fan working power according to the gas composition monitored in real time by the gas composition detector to adjust the air velocity of the airflow; at the same time, the control center can also adjust the adsorption temperature of each adsorption bed according to the gas composition monitored in real time by the gas composition detector, so that each adsorption bed can have the most suitable air velocity and gas residence time, and the most suitable adsorption temperature, so that the VOC in the organic waste gas can be adsorbed and fixed to the greatest extent, achieving enrichment and concentration, which is convenient for centralized combustion / catalytic combustion treatment.

[0025] According to a preferred embodiment of the present invention, the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed can be in the form of a tower body or a tank body, which is completely closed, the adsorption medium is evenly filled inside, and the two ends are respectively provided with pipeline connection parts. Preferably, the upper end of the tower body or the tank body is the first end, and the lower end is the second end; in this way, the adsorption process can be realized as adsorption from top to bottom in each adsorption bed body, and the desorption process is elution from bottom to top.

[0026] According to a preferred embodiment of the present invention, the number of the non-polar component adsorption beds, water vapor adsorption beds and polar component adsorption beds is 2 or more groups, and the control center controls the 2 or more groups of non-polar component adsorption beds, water vapor adsorption beds and polar component adsorption beds to alternately perform adsorption and desorption (regeneration) to achieve a relay-type continuous adsorption operation of organic waste gas.

[0027] In a second aspect, the present invention provides an adsorption treatment method for organic waste gas containing polar components, which is implemented by using the adsorption treatment system described in any of the above embodiments.

[0028] (III) Beneficial effects

[0029] The beneficial effects of the present invention are:

[0030] The present invention mainly aims at establishing a reasonable adsorption treatment system for large-volume, low-concentration organic waste gas containing polar components. According to the adsorption treatment system and method for organic waste gas containing polar components, non-polar components, water vapor and polar components are treated separately using different adsorbent beds (filled with adsorbents of different properties). Before the organic waste gas enters the polar component adsorption bed, most of the non-polar components and water vapor are removed in advance using appropriate adsorption materials, which greatly improves the treatment efficiency and effect of the organic waste gas (especially the polar components), and can ensure that the polar components that are difficult to remove by conventional means meet the emission standards.

[0031] Furthermore, the present invention also includes a desorption system. When the tail gas produced by the adsorption bed is monitored to be substandard (still containing excessive non-polar, water or polar small molecule VOC), it indicates that the adsorption bed has reached a saturated state and needs to be regenerated. At this time, the adsorption mode is switched to the desorption mode, that is: the adsorption inlet valve and outlet valve at both ends of each adsorption bed are closed, the valves and (catalytic) burners of the desorption system are opened, and a desorption medium (tail gas generated by the burner) with a certain initial temperature is introduced into each adsorption bed from the desorption medium supply end to achieve the effect of desorbing VOC in each adsorption bed (heating, evaporation and drying for the water vapor adsorption bed), and the generated desorption gas is uniformly collected to the burner at the desorption gas treatment end for catalytic combustion, so as to achieve the effect of degrading VOC and making the organic waste gas containing polar components harmless. The tail gas generated by the combustion at the desorption gas treatment end is introduced into the desorption medium supply end for use as a desorption medium, and the initial temperature can reach 250-280°C, saving the energy required for the cold medium to heat up and desorb (desorption requires a higher temperature). To control production safety, a flame arrester is installed near the desorption medium supply end. To prevent the desorption medium from entering the non-polar component adsorption bed (activated carbon) at too high a temperature, which may lead to oxidation of the activated carbon, a cooler (such as an air cooler, which exchanges with air to cool down) is installed between the desorption medium and the non-polar component adsorption bed to reduce the desorption medium temperature to 80-120°C.

[0032] Furthermore, the present invention is provided with a control center and a gas composition detector arranged near the chimney and near the desorption gas processing end. The control center is communicatively connected with the gas composition detector. The control center is also communicatively connected with each valve of the system, the temperature control device of each adsorption bed, the fan, the burner, the induced draft speed (the speed of introducing exhaust gas) at the desorption gas supply end, the nitrogen and exhaust gas switching valve at the desorption gas supply end, etc., and can automatically switch the adsorption mode and the desorption mode according to the degree of adsorption treatment and the degree of desorption treatment, automatically adjust and control the air velocity in the adsorption and desorption modes, the adsorption / desorption temperature of each adsorption bed, and automatically switch the nitrogen gas source when necessary to cool and purge each adsorption bed that has completed desorption, so as to prepare for the adsorption operation again.

[0033] In the present invention, the adsorption material of the adsorption bed can be flexibly filled according to the composition of the organic waste gas, thereby improving the adaptability of the system; when multiple groups of non-polar component adsorption beds, water adsorption beds and polar component adsorption beds are operated in parallel, the desorption gas treatment ends of the multiple groups of adsorption beds can be connected to the same burner, and different groups of adsorption beds can be alternately adsorbed and desorbed and regenerated, thereby realizing the relay-type continuous adsorption, fixed enrichment and combustion operations of the organic waste gas, improving the treatment efficiency of the organic waste gas, and avoiding equipment damage caused by repeated start and stop of the burner. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1It is a schematic diagram of the adsorption treatment system of organic waste gas containing polar components of the present invention.

[0035] Figure 2 It is a control relationship diagram of the adsorption treatment system of organic waste gas containing polar components of the present invention. Description of the drawings:

[0037] Symbols 8-13 represent valves in the adsorption mode, which are: first adsorption inlet valve 8, first adsorption outlet valve 9, second adsorption inlet valve 10, second adsorption outlet valve 11, third adsorption inlet valve 12, third adsorption outlet valve 13; symbols 14-19 represent valves in the desorption mode.

[0038] 4 is a fan, 5 is a chimney, 6 is a flame arrester, 7 is an air cooler, 20 is a gas composition detector at the desorption gas processing end, 21 is a gas composition detector for the exhaust gas entering the chimney, 22 is a control center, 23 is a desorption medium supply end, 231 is a catalytic combustion exhaust gas input end, 232 is a nitrogen gas source input end, 24 is a desorption gas processing end, and 241 is a catalytic burner. DETAILED DESCRIPTION

[0039] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0040] like Figure 1 As shown, it is a schematic diagram of an adsorption treatment system for organic waste gas according to a preferred embodiment of the present invention, wherein the system comprises a non-polar component adsorption bed 1, a water vapor adsorption bed 2 and a polar component adsorption bed 3, a fan 4, a chimney 5, a flame arrester 6, an air cooler 7, a valve group 8-13 of the adsorption system and a valve group 14-19 of the desorption system, a desorption medium supply end 23, an adsorption gas treatment end 24, a gas composition detector 20 (21) and a control center 22, and other components, as well as a plurality of pipelines. The pipelines include: a connecting pipeline between the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3, a connecting pipeline between the desorption medium supply end 23 and each adsorption bed, a connecting pipeline between each adsorption bed and the adsorption gas treatment end 24, an exhaust pipeline from the adsorption gas treatment end 24 to the desorption medium supply end 23, and a pipeline for organic waste gas to enter the non-polar component adsorption bed 1.

[0041] The adsorbent material used in the non-polar component adsorption bed 1 is one of granular or honeycomb activated carbon, and the adsorbent material used in the water vapor adsorption bed 2 is one of spherical 3A, 4A, 5A, and 13X molecular sieves with a diameter of 2-5 mm. The adsorbent material used in the polar component adsorption bed 3 is one of ZSM-4, ZSM-5, ZSM-12, and ZSM-20 modified with nickel or molybdenum metal.

[0042] The modification methods of the ZSM molecular sieve modified by nickel or molybdenum metal include an impregnation method and a solid phase method; the impregnation method is to impregnate the ZSM molecular sieve into a nickel or molybdenum water-soluble salt, then separate the molecular sieve, and perform oxygen roasting to obtain the nickel or molybdenum metal-modified ZSM molecular sieve; the solid phase method is to ball-mill the oxide or metal salt of nickel or molybdenum, and then mix and roast it with the molecular sieve to obtain the nickel or molybdenum metal-modified ZSM molecular sieve. The molybdenum water-soluble salt can use ammonium molybdate, and the nickel water-soluble salt can use nickel acetate, nickel chloride, nickel nitrate, etc. The nickel or molybdenum metal-modified ZSM molecular sieve can also be a commercial product.

[0043] The method for treating organic waste gas containing polar components using the above-mentioned adsorption treatment system includes two processes: adsorption and desorption. When the adsorption process begins, close each valve in the desorption valve group 14-19 in the desorption pipeline, open each valve in the adsorption valve group 8-13 in the adsorption pipeline, and -1 At an air velocity of , the organic waste gas containing polar components is passed through the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3, the fan 4 and the chimney 5 in sequence. It is discharged after being tested to meet the standards. If it does not meet the standards after testing, it means that the adsorption bed is saturated with adsorption and needs to be transferred to the desorption process. During the adsorption process, the temperature of the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 is controlled not to exceed 50°C. Among them, a gas composition detector 21 can be set in the chimney 5 or before entering the chimney 5. The gas composition detector 21 is used to monitor in real time whether the exhaust gas entering the chimney 5 meets the requirements. The gas composition detector 21 is connected to the control center 22 for communication. In addition, the temperature control device outside or inside the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 enables each adsorption bed to adsorb the corresponding components of the organic waste gas under a favorable temperature environment.

[0044] When the standard is not met after detection, the adsorption treatment system enters the desorption mode (desorption and regeneration of the adsorption bed), closes each valve in the adsorption valve group 8-13 in the adsorption pipeline, opens each valve in the desorption valve group 14-19 in the desorption pipeline, introduces 250-280°C catalytic combustion exhaust gas as the desorption medium, and enters the polar component adsorption bed 3 and the water vapor adsorption bed 2 from the bottom after passing through the flame arrester 6 (the adsorbent in the water vapor adsorption bed 2 is dried with hot desorption medium), and the other catalytic combustion exhaust gas is cooled to 80-120°C by the air cooler 7 and enters the non-polar component adsorption bed 1 from the bottom; the concentrated gas flowing out from the top of the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 is combined and sent to the catalytic burner 241 for further combustion treatment. A gas composition detector 20 is provided in front of the catalytic burner 241 to detect the total VOC concentration in the desorbed concentrated gas. When the VOC concentration is less than 50mg / m 3, it indicates that the adsorption bed regeneration is completed, the desorption operation is stopped, and the catalytic combustion tail gas input end 231 is switched to the nitrogen input 232 at room temperature. The non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 are purged and cooled to room temperature by introducing nitrogen into the adsorption bed. After reaching room temperature, they can quickly adapt to the next round of adsorption operation mode. Among them, the desorption medium supplied by the desorption medium supply end 23 comes from the combustion tail gas generated by the burner 241 of the desorption gas treatment end 24 to burn the concentrated VOC. It has a certain initial temperature and can be directly used as a desorption medium. Of course, the heat generated by the burner 241 can also be used to heat the external inert gas source to desorb the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3. Among them, the air velocity through the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 is 500-1000h -1 .

[0045] like Figure 2 As shown, the control center 22 can be communicated with the gas composition detector 20 arranged near the desorption gas processing end and the gas composition detector 21 arranged in the chimney 5. The control center is also communicated with the valves of the adsorption valve group 8-13, the valves of the desorption valve group 14-19, the external or internal temperature control devices of the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3, the drive circuit of the fan 4, the burner 241, the induced draft machine at the desorption gas supply end, the nitrogen and tail gas switching valve at the desorption gas supply end, etc., and can automatically switch the adsorption mode and the desorption mode according to the degree of adsorption treatment and the degree of desorption treatment, automatically adjust and control the air velocity in the adsorption and desorption modes, the adsorption / desorption temperature of the adsorption bed, and automatically switch the nitrogen gas source when necessary to cool and purge each desorption-completed adsorption bed to prepare for the next adsorption operation.

[0046] After adopting the above technical scheme, the beneficial effects of the present invention are as follows: since the adsorption treatment system and method for organic waste gas containing polar components respectively treats non-polar components, water vapor and polar components with different adsorbents, the treatment efficiency and effect are greatly improved, and the polar components that are difficult to remove by conventional means can be guaranteed to meet the emission standards; the catalytic combustion tail gas is used as the desorption medium, which saves the energy required for the desorption of cold medium by heating (the medium that requires a higher temperature for desorption); the adsorption materials of each adsorption bed can be flexibly filled according to the composition of the organic waste gas, thereby improving the adaptability of the system; when multiple sets of non-polar component adsorption beds, water adsorption beds and polar component adsorption beds are operated in parallel, the desorption gas treatment ends of the multiple groups of adsorption beds can be connected to the same burner, and different groups of adsorption beds can be alternately adsorbed and desorbed and regenerated, realizing the relay-type continuous adsorption, fixed enrichment and combustion operations of the organic waste gas, improving the treatment efficiency of the organic waste gas, and avoiding equipment damage caused by repeated start and stop of the burner.

[0047] The following is an example of a specific application of the organic waste gas adsorption treatment system of the present invention.

[0048] Example 1

[0049] This embodiment provides an adsorption treatment system for organic waste gas containing polar components, which is composed of a non-polar component adsorption bed 1, a water vapor adsorption bed 2, a polar component adsorption bed 3, a fan 4, a chimney 5, a flame arrester 6, an air cooler 7, an adsorption valve group 8-13 and a desorption valve group 14-19, and an adsorption pipeline, a desorption pipeline and a nitrogen purge pipeline connected to the above equipment. Among them, the adsorption material used in the non-polar component adsorption bed 1 is granular activated carbon, the adsorption material used in the water vapor adsorption bed 2 is a spherical 3A molecular sieve with a diameter of 2 mm, and the adsorption material used in the polar component adsorption bed 3 is nickel-modified ZSM-5.

[0050] Embodiment 2-5

[0051] In Examples 2-5, except that the adsorption materials used in the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 are different, the rest are the same as in Example 1, as shown in Table 1.

[0052] Table 1 Description of processing system embodiment

[0053] Non-polar component adsorption bed Water vapor adsorption bed Polar component adsorption bed Example 2 Granular activated carbon 2mm 3A molecular sieve Molybdenum metal modified ZSM-4 Example 3 Honeycomb activated carbon 3mm 4A molecular sieve Nickel metal modified ZSM-12 Example 4 Honeycomb activated carbon 4mm 5A molecular sieve Molybdenum metal modified ZSM-5 Example 5 Honeycomb activated carbon 5mm 13X molecular sieve Nickel metal modified ZSM-20

[0054] Example 6

[0055] The simulated organic waste gas contains ethyl acetate (non-polar component) 1000 mg / m 3 , water vapor 850mg / m 3 , methanol (polar component) 1000mg / m 3 The above organic waste gas was treated by adsorption using the device in Example 1. The valves in the desorption valve group 14-19 in the desorption pipeline were closed, and the valves in the adsorption valve group 8-13 in the adsorption pipeline were opened. -1 At an air velocity of 1.5 s, the organic waste gas containing polar components was passed through the non-polar component adsorption bed 1, the water vapor adsorption bed 2, the polar component adsorption bed 3, the fan 4 and the chimney 5 in sequence. After adsorption for 1 hour, the concentration of the non-polar component at the outlet was measured to be 4 mg / m 3 , the concentration of polar components is 7mg / m 3 , the total VOC concentration is 11mg / m 3 , meeting emission requirements.

[0056] When the desorption process occurs, close each valve in the adsorption valve group 8-13 in the adsorption pipeline, open each valve in the desorption valve group 14-19 in the desorption pipeline, introduce 250°C catalytic combustion exhaust gas as the desorption medium, and enter the polar component adsorption bed 3 and the water vapor adsorption bed 2 from the bottom after passing through the flame arrester 6. Another stream of catalytic combustion exhaust gas is cooled to 80°C by the air cooler 7 and enters the non-polar component adsorption bed 1 from the bottom; the concentrated gas flowing out from the top of the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 is combined and sent to the catalytic combustion device for further combustion treatment. The air velocity of the desorption medium passing through the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 is 500h -1 After 5 hours, the total VOC concentration in the concentrated gas is less than 50 mg / m 3 After desorption is completed, the catalytic combustion tail gas is switched to room temperature nitrogen, so that the temperature of the non-polar component adsorption bed 1, the water vapor adsorption bed 2 and the polar component adsorption bed 3 drops to room temperature to facilitate the next adsorption process.

[0057] Examples 7-10

[0058] In Examples 7-10, the adsorption system in Examples 2-5 was used, the composition of the organic waste gas was the same as that in Example 6, and the specific conditions of adsorption and desorption were changed. The results are shown in Table 2.

[0059]

[0060] As shown in the table above, after 1 hour of adsorption, the total VOC concentration at the outlet was measured to be 13-20 mg / m 3 , which can meet the emission requirements. It can be seen from Examples 6-10 that the present invention is a reasonable adsorption treatment system for large-volume and low-concentration organic waste gas containing polar components. When treating large-volume and low-concentration organic waste gas containing polar components, it can achieve efficient adsorption of polar small molecular substances and stable emission that meets the standards.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adsorption treatment system for organic waste gas containing polar components, characterized in that: It includes: A non-polar component adsorption bed, a water vapor adsorption bed and a polar component adsorption bed; wherein the non-polar component adsorption bed is filled with granular or honeycomb activated carbon; the water vapor adsorption bed is filled with spherical molecular sieves; and the polar component adsorption bed is filled with ZSM molecular sieves modified with nickel or molybdenum metals; The non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are arranged in sequence according to the flow direction of the organic waste gas, so that the non-polar component in the organic waste gas is first adsorbed and fixed by the non-polar component adsorption bed, then is dehumidified and dried by the water vapor adsorption bed, and finally the polar component in the organic waste gas is adsorbed and fixed by the polar component adsorption bed; The non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are respectively provided with a first end and a second end; the first end of the non-polar component adsorption bed is connected to the organic waste gas, and the second end is connected to the first end of the water vapor adsorption bed; the second end of the water vapor adsorption bed is connected to the first end of the polar component adsorption bed; the second end of the polar component adsorption bed is connected to a fan, and the fan is connected to a chimney; The adsorption treatment system also includes a desorption system; the desorption system includes a desorption medium supply end and a desorption gas treatment end; the desorption medium supply end is connected to one end of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed through pipelines and independent control valves, respectively, and the desorption gas treatment end is connected to the other ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed through pipelines and independent control valves, respectively; The desorption gas treatment end is connected to a burner, which combines the waste gas eluted from the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed for combustion treatment and produces tail gas; the desorption medium supply end is connected to the tail gas discharge port of the burner to obtain the elution medium with a certain initial temperature, and the desorption medium supply end is also connected to a nitrogen gas source; the combustion tail gas and the nitrogen gas source connected to the desorption medium supply end can be switched; The desorption medium supply end is connected to a main pipeline, and a flame arrester is provided on the main pipeline near the desorption medium supply end; the main pipeline is connected to the second ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed respectively through a plurality of branch pipes and independent control valves provided on each branch pipe; wherein the branch pipe connected to the non-polar component adsorption bed is A cooler is provided to reduce the temperature of the combustion tail gas before passing it into the non-polar component adsorption bed; The chimney and the desorption gas processing end are both provided with a gas composition detector; the gas composition detector is connected to a control center, and the control center signals control the adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed, as well as the valves of the desorption system.

2. The adsorption treatment system according to claim 1, characterized in that: The spherical molecular sieve in the water vapor adsorption bed is one of spherical 3A, 4A, 5A, and 13X molecular sieves; the ZSM series molecular sieve in the polar component adsorption bed is any one of ZSM-4, ZSM-5, ZSM-12 and ZSM-20.

3. The adsorption treatment system according to claim 1, characterized in that: The first end of the non-polar component adsorption bed is provided with a first adsorption air inlet valve, and the second end is provided with a first adsorption air outlet valve; the first end of the water vapor adsorption bed is provided with a second adsorption air inlet valve, and the second end is provided with a second adsorption air outlet valve; the first end of the polar component adsorption bed is provided with a third adsorption air inlet valve, and the second end is provided with a third adsorption air outlet valve; the first end of the non-polar component adsorption bed is connected to the organic waste gas through the first adsorption air inlet valve, and the second end is connected to the first end of the water vapor adsorption bed through the first adsorption air outlet valve and the second adsorption air inlet valve; the second end of the water vapor adsorption bed is connected to the first end of the polar component adsorption bed through the second adsorption air outlet valve and the third adsorption air inlet valve; the second end of the polar component adsorption bed is connected to the fan through the third adsorption air outlet valve.

4. The adsorption treatment system according to claim 1, characterized in that: When the adsorption treatment system starts working, the control center controls the adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed to be connected, and the valves of the desorption system are closed; at this time, the organic waste gas flows through the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed in sequence, and the tail gas enters the chimney; When a gas composition detector installed in the chimney detects that the tail gas does not meet the standard, it means that at least one of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed is saturated with adsorption and needs to be desorbed. At this time, the control center controls the adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed to be closed, and at the same time, the valves of the desorption system are connected, and the gas with a relatively high initial temperature is supplied from the desorption medium supply end to the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed for elution treatment. The eluted gas enters the burner at the desorption gas treatment end for combustion and generates combustion tail gas; When the gas composition detector in the desorption gas treatment end detects that the VOC concentration is lower than the preset value, it means that the elution of each adsorption bed is completed. At this time, the control center controls the desorption medium supply end to switch to a nitrogen gas source, and uses the nitrogen gas source to purge and cool the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed to room temperature, and then controls the valves of the desorption system to close. At the same time, the adsorption inlet valves and the adsorption outlet valves at both ends of the non-polar component adsorption bed, the water vapor adsorption bed and the polar component adsorption bed are connected, and the adsorption treatment of the organic waste gas is carried out again.

5. The adsorption treatment system according to claim 4, characterized in that: The non-polar component adsorption bed, water vapor adsorption bed and polar component adsorption bed are also respectively provided with temperature control devices to ensure that the organic waste gas is at the most favorable adsorption temperature during the adsorption process; the control center can adjust the opening of each valve, the working power of the fan, and the adsorption temperature of the non-polar component adsorption bed, water vapor adsorption bed and polar component adsorption bed.

6. The adsorption treatment system according to claim 1, characterized in that: The number of the non-polar component adsorption beds, water vapor adsorption beds and polar component adsorption beds is 2 or more groups, and the control center controls the 2 or more groups of non-polar component adsorption beds, water vapor adsorption beds and polar component adsorption beds to alternately perform adsorption and desorption, thereby realizing a relay-type continuous adsorption operation for organic waste gas.

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