VOC catalytic fuel waste gas treatment method

Abstract

The invention discloses a VOC (volatile organic compound) catalytic fuel waste gas treatment method in the technical field of waste gas treatment, which comprises the following steps: S100, pretreating waste gas, controlling the temperature and humidity of the waste gas, and removing particulate matters in the waste gas; and S200, adsorbing and concentrating the pretreated waste gas through an adsorbent. By combining adsorption concentration and combustion catalysis, the waste gas treatment efficiency is improved, and the VOC waste gas can be quickly decomposed into harmless CO2 and H2O. Hot air is used for desorption and combustion catalysis, energy consumption is reduced, high-temperature gas is cooled through the tubular heat exchanger, and the energy utilization efficiency is further improved. Through strict detection and split-flow treatment, it is ensured that the discharged tail gas reaches the emission standard, and the risk of secondary pollution is reduced. Through secondary adsorption and secondary heating desorption regeneration, VOC waste gases with different concentrations and types can be treated, and the flexibility and applicability of the method are improved.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas treatment, in particular to a method for treating VOC catalytic fuel waste gas. Background Art

[0002] VOC refers to volatile organic compounds. According to the definition of the World Health Organization, if the boiling point is between 50℃ and 250℃ at normal pressure of 101.32kPa, it exists in the form of gas at room temperature; but the definition in the environmental sense refers to a class of active volatile organic compounds, that is, the class of volatile organic compounds that can cause harm. The structure of VOC determines that they can quickly turn into a gas state at room temperature. This class of compounds includes a variety of components, such as formaldehyde, benzene, propylene, etc., which are widely present in daily life and industrial production such as chemical products, building materials, detergents, and automobile exhaust. Although VOCs play an important role in certain products and processes, their volatile nature also brings potential environmental and health problems. The volatilization of VOCs can cause air pollution, participate in the formation of ozone and fine particulate matter, and may have adverse effects on human health, such as respiratory problems and exposure to harmful substances.

[0003] Traditional VOC waste gas treatment methods include direct combustion, condensation recovery, absorption and adsorption, but these methods often have problems such as high energy consumption, low treatment efficiency or secondary pollution. In order to overcome these shortcomings, it is necessary to develop an efficient, energy-saving and environmentally friendly VOC catalytic fuel waste gas treatment method. Summary of the invention

[0004] The object of the present invention is to provide a VOC catalytic fuel exhaust gas treatment method to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for treating VOC catalytic fuel exhaust gas, comprising the following steps:

[0006] S100: pre-treat the exhaust gas, control the temperature and humidity of the exhaust gas, and remove particulate matter in the exhaust gas;

[0007] S200: Adsorbing and concentrating the pre-treated waste gas through an adsorbent;

[0008] S300: using hot air to burn and catalyze the adsorbed exhaust gas, and detecting and diverting the catalyzed exhaust gas. If the exhaust gas meets the emission standard, it will enter step S600. If the exhaust gas does not meet the emission standard, it will enter step S400.

[0009] S400: secondary adsorption and concentration of waste gas that does not meet the emission standards after desorption by adsorbent;

[0010] S500: performing secondary heating, desorption and regeneration of the waste gas after secondary adsorption, and performing combustion catalysis;

[0011] S600: After the desorption and regeneration, the high-temperature gas is cooled through a tube-in-tube heat exchanger and then tested. It is then discharged after meeting the emission standards.

[0012] As a further solution of the present invention: in the step S100, particulate matter in the exhaust gas is removed by a dry filter and a cyclone plate tower, and the temperature of the exhaust gas is controlled at 40° C. and the humidity is controlled at 65%-80%.

[0013] As a further solution of the present invention: in the step S200, a multi-unit combined filtering layered adsorption bed is used, wherein the adsorption bed uses honeycomb activated carbon as an adsorbent to adsorb the exhaust gas.

[0014] As a further solution of the present invention: in the step S300, when the adsorbent is fully adsorbed, the gas is heated to 80°C by an electric heater, and desorption is performed by high-temperature gas. The high-concentration organic waste gas after desorption is preheated to 250°C and burned through a catalytic bed. After combustion, the waste gas is decomposed into CO2 and H2O.

[0015] As a further solution of the present invention: in step S400, the adsorbent is replaced with crushed activated carbon to perform secondary adsorption on the exhaust gas.

[0016] As a further solution of the present invention: in the step S500, the waste gas after the secondary adsorption is heated for the second time, and the secondary desorption and combustion reaction are completed.

[0017] As a further solution of the present invention: in the step S600, the high temperature gas after catalysis is cooled down, and the exhaust gas is tested after cooling down, and is discharged into the atmosphere after meeting the emission standards.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: In the present invention, the efficiency of waste gas treatment is improved by combining adsorption concentration and combustion catalysis, and VOC waste gas can be quickly decomposed into harmless CO2 and H2O. The use of hot air for desorption and combustion catalysis reduces energy consumption, and the high-temperature gas is cooled by a tube-in-tube heat exchanger, further improving energy efficiency. After strict testing and diversion treatment, it is ensured that the exhaust gas meets the emission standards and reduces the risk of secondary pollution. Through secondary adsorption and secondary heating desorption regeneration, VOC waste gas of different concentrations and types can be treated, which improves the flexibility and applicability of the method. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a schematic flow chart of a VOC catalytic fuel waste gas treatment method of the present invention. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0022] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected or set, or detachably connected or set, or integrally connected or set. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] See also Figure 1 ,

[0025] Embodiment 1:

[0026] Scenario: VOC waste gas treatment in a chemical plant

[0027] Processing flow:

[0028] Exhaust gas pretreatment: Use a dry filter to initially remove large particles in the exhaust gas, and then use a cyclone plate tower to further remove fine particles. At the same time, the exhaust gas temperature is controlled at 40°C and the humidity is 70%.

[0029] Adsorption concentration: A multi-unit combined filtering and layered adsorption bed containing honeycomb activated carbon is used as an adsorbent to adsorb the pretreated exhaust gas to concentrate VOCs.

[0030] Combustion catalysis: When the adsorption bed is saturated, the gas is heated to 80°C by an electric heater for desorption. The high-concentration organic waste gas after desorption is preheated to 250°C and then sent to the catalytic bed for combustion, decomposing into CO2 and H2O. The waste gas after combustion is tested, and if it meets the standard, it will proceed to the next step.

[0031] The exhaust gas is tested through the detection probe and the three-way pipe. If it meets the emission standards, it will enter the emission step for discharge. If it does not meet the emission standards, secondary adsorption will be carried out.

[0032] Emission treatment: The exhaust gas that meets the standards is cooled to an appropriate temperature through a tube-in-tube heat exchanger, and then tested again to ensure that it meets the standards before being discharged into the atmosphere. If the test fails to meet the standards, it will enter the secondary adsorption concentration process.

[0033] Results: The VOCs concentration in the waste gas after treatment by this process was significantly reduced, meeting environmental emission standards.

[0034] Summary: Pretreatment stage: The exhaust gas is pretreated through a dry filter and a cyclone plate tower to remove particulate matter in the exhaust gas, while the temperature of the exhaust gas is controlled at 40°C and the humidity is controlled at 65%-80%.

[0035] Adsorption and concentration stage: a multi-unit combined filtering and layered adsorption bed is used, in which honeycomb activated carbon is used as an adsorbent to adsorb and concentrate the pre-treated exhaust gas.

[0036] Combustion catalysis stage: When the adsorbent is fully adsorbed, the gas is heated to 80°C by an electric heater for desorption. The high-concentration organic waste gas after desorption is preheated to 250°C and then passed through a catalytic bed for combustion catalysis, decomposing into CO2 and H2O.

[0037] Detection and diversion stage: The exhaust gas after catalysis is tested. If it meets the emission standards, it proceeds to the next step; if it does not meet the emission standards, the adsorbent is replaced with crushed activated carbon for secondary adsorption and concentration.

[0038] Secondary heating, desorption and regeneration stage: The exhaust gas after secondary adsorption is subjected to secondary heating, desorption and regeneration treatment, and then passes through the catalytic bed for combustion catalysis again.

[0039] Cooling and emission stage: After desorption and regeneration, the high-temperature gas is cooled through a shell-and-tube heat exchanger. After cooling, the exhaust gas is tested again to ensure that it meets the emission standards before being discharged.

[0040] Through the description of the above embodiments, the specific operation steps and advantages of the VOC catalytic fuel exhaust gas treatment method of the present invention can be clearly seen.

[0041] Embodiment 2

[0042] Scenario: VOC waste gas treatment in automobile paint shop

[0043] Processing flow:

[0044] Exhaust gas pretreatment: A wet filter is used to remove oil mist and particulate matter in the exhaust gas, while the exhaust gas temperature is controlled at 38°C and the humidity is 68%.

[0045] Adsorption and concentration: Use activated carbon fiber as an adsorbent to efficiently adsorb and concentrate the pre-treated exhaust gas.

[0046] Combustion catalysis: After adsorption saturation, it is desorbed by hot air. The desorbed exhaust gas is preheated to 240°C and sent to the catalytic combustion device for combustion decomposition.

[0047] Secondary treatment and emission: The waste gas after combustion is subjected to secondary testing. If it does not meet the standard, secondary adsorption and combustion treatment are carried out until it meets the standard. The waste gas that meets the standard is discharged after cooling treatment.

[0048] Result: The VOC exhaust gas in the paint shop was effectively treated and the air quality was significantly improved.

[0049] Embodiment 3

[0050] Scenario: VOC waste gas treatment in printing plants

[0051] Processing flow:

[0052] Exhaust gas pretreatment: Use bag filter to remove large particles in the exhaust gas, and then use cyclone dust collector to further remove fine particles, while controlling the exhaust gas temperature at 42℃ and humidity at 75%.

[0053] Adsorption and concentration: A multi-layer adsorption bed containing granular activated carbon is used as an adsorbent to deeply adsorb and concentrate the pre-treated exhaust gas.

[0054] Combustion catalysis: When the adsorption bed is saturated with adsorption, a hot air blower is used to heat the gas to 85°C for desorption. The desorbed exhaust gas is preheated to 255°C and then sent to the catalytic bed for combustion and decomposition.

[0055] Purification and emission: The exhaust gas after combustion is cooled by a tube-in-tube heat exchanger and then further purified by a wet desulfurization and dust removal device to ensure that the exhaust gas meets the emission standards.

[0056] Result: The VOC waste gas of the printing factory was effectively controlled, reducing the pollution to the surrounding environment.

[0057] Pretreatment: Remove particulate matter from the exhaust gas through dry filters and cyclone plate towers, and control the temperature and humidity of the exhaust gas within an appropriate range.

[0058] Adsorption and concentration: A multi-unit combined filtering and layered adsorption bed is used, and honeycomb activated carbon is used to adsorb and concentrate the pre-treated exhaust gas to increase the concentration of VOC in the exhaust gas.

[0059] Combustion catalysis: When the adsorbent is fully adsorbed, the gas is heated to a suitable temperature by an electric heater for desorption. The high-concentration organic waste gas after desorption is preheated and then passed through a catalytic bed for combustion catalysis to decompose into CO2 and H2O.

[0060] Detection and diversion: The exhaust gas after catalysis is tested. If it meets the emission standards, it will directly enter the cooling and emission stage. If it does not meet the standards, it will undergo secondary adsorption and secondary heating and desorption regeneration treatment.

[0061] Cooling emission: After desorption and regeneration, the high-temperature gas is cooled by a shell-and-tube heat exchanger. After cooling, the exhaust gas is tested again to ensure that it meets the emission standards before being discharged.

[0062] When using this method to treat VOC catalytic fuel exhaust gas, the following problems may be encountered:

[0063] Complexity of exhaust gas composition:

[0064] Exhaust gas may contain a variety of different VOCs components, and the concentration and proportion may change over time, making treatment more difficult.

[0065] It is necessary to select appropriate adsorbents, catalysts and treatment processes for VOCs with different components.

[0066] Processing efficiency and stability:

[0067] The saturation and regeneration efficiency of the adsorbent and catalyst directly affect the treatment efficiency.

[0068] The stability of equipment and processes is critical to long-term operation, and any failure may lead to processing interruption or loss of efficiency.

[0069] High temperature and corrosive environment:

[0070] Some VOCs waste gases may be hot or corrosive, which places higher demands on the selection of equipment and materials.

[0071] Special precautions are required to ensure the safety of equipment and personnel.

[0072] The solution is as follows:

[0073] Complexity of exhaust gas composition:

[0074] Conduct detailed exhaust gas composition analysis to understand the types, concentrations and proportions of VOCs in the exhaust gas.

[0075] According to the analysis results, select appropriate treatment technology and equipment, such as adsorption, catalytic combustion, biological method, etc.

[0076] For waste gas containing multiple components, combined treatment technology can be considered to improve treatment efficiency.

[0077] Processing efficiency and stability:

[0078] Select high-quality adsorbents, catalysts and equipment to ensure good performance and stability.

[0079] Regularly monitor and maintain equipment and processes to identify and resolve problems in a timely manner.

[0080] Optimize processing parameters such as temperature, pressure, flow rate, etc. to improve processing efficiency.

[0081] High temperature and corrosive environment:

[0082] Select high temperature resistant and corrosion resistant materials and equipment, such as stainless steel, titanium alloy, etc.

[0083] Carry out insulation and anti-corrosion treatment on equipment and pipelines to extend their service life.

[0084] Strengthen safety monitoring and protection measures to ensure the safety of equipment and personnel.

[0085] Summarize:

[0086] S100: Exhaust gas pretreatment

[0087] Equipment: Use a combination of dry filter and cyclone plate tower.

[0088] Operation: The exhaust gas is introduced into a dry filter to remove larger particles, and then further removed through a cyclone plate tower to remove fine particles. At the same time, the temperature and humidity of the exhaust gas are adjusted to stabilize the temperature of the exhaust gas at 40°C and the humidity is maintained between 65% and 80%.

[0089] S200: Exhaust gas adsorption concentration

[0090] Equipment: It adopts a multi-unit combined filtering and layered adsorption bed, and the adsorption bed is filled with honeycomb activated carbon.

[0091] Operation: The pretreated waste gas is sent to the adsorption bed for efficient adsorption by honeycomb activated carbon to concentrate the VOCs in the waste gas.

[0092] S300: Combustion catalysis and detection split

[0093] Equipment: Electric heater and catalytic bed.

[0094] Operation: When the adsorbent is fully adsorbed, close the air inlet valve, start the electric heater to heat the gas in the adsorption bed to 80°C for desorption, and preheat the desorbed high-concentration organic waste gas to 250°C before sending it to the catalytic bed for combustion catalysis. The waste gas is decomposed into CO2 and H2O. After the exhaust gas is burned, if it meets the emission standard, it will directly enter the S600 step; if it does not meet the standard, it will enter the S400 step.

[0095] S400: Secondary adsorption concentration

[0096] Equipment: Replace the adsorption bed with crushed activated carbon.

[0097] Operation: The waste gas that does not meet the standards in step S300 is sent to an adsorption bed containing crushed activated carbon for secondary adsorption to further concentrate VOCs.

[0098] S500: Secondary heating desorption and combustion catalysis

[0099] Equipment: Again, electric heaters and catalytic beds are used.

[0100] Operation: The waste gas after secondary adsorption is heated and desorbed for the second time, and the desorbed waste gas is sent to the catalytic bed again for combustion catalysis to ensure that the VOCs in the waste gas are completely decomposed.

[0101] S600: Cooling and Emissions

[0102] Equipment: Shell and tube heat exchanger.

[0103] Operation: The high-temperature gas after catalysis is cooled through a tube-in-tube heat exchanger. After it drops to a temperature suitable for emission, it is tested again to ensure that the exhaust gas meets the emission standards before being discharged.

[0104] The working principle of the present invention is: This VOC catalytic fuel waste gas treatment method is based on the principle of adsorption-catalytic combustion. First, the particulate matter in the waste gas is removed by pretreatment, and the temperature and humidity of the waste gas are adjusted to ensure the stability of the subsequent treatment process. Then, the adsorption capacity of activated carbon is used to efficiently adsorb and concentrate the VOCs in the waste gas. When the adsorbent reaches saturation, the concentrated VOCs are released by heating and desorption, and preheated to a suitable temperature for catalytic combustion to decompose the VOCs into harmless CO2 and H2O. If the waste gas still does not meet the emission standards after the first catalytic combustion, secondary adsorption concentration and secondary catalytic combustion are carried out to ensure complete purification of the waste gas. Finally, the treated waste gas is cooled and discharged after meeting the emission standards.

[0105] During the entire treatment process, precise temperature control and catalytic combustion technology are used to achieve efficient removal and purification of VOCs, reducing the pollution of waste gas to the environment. At the same time, through the recycling of adsorbents, the treatment cost is reduced and the treatment efficiency is improved.

[0106] It should be noted that, in this article, the terms "comprise", "include" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0107] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A method for treating VOC catalytic fuel exhaust gas, characterized in that: The steps include: S100: pre-treat the exhaust gas, control the temperature and humidity of the exhaust gas, and remove particulate matter in the exhaust gas; S200: Adsorbing and concentrating the pre-treated waste gas through an adsorbent; S300: using hot air to burn and catalyze the adsorbed exhaust gas, and detecting and diverting the catalyzed exhaust gas. If the exhaust gas meets the emission standard, it will enter step S600. If the exhaust gas does not meet the emission standard, it will enter step S400. S400: secondary adsorption and concentration of waste gas that does not meet the emission standards after desorption through adsorbent; S500: performing secondary heating, desorption and regeneration of the waste gas after secondary adsorption, and performing combustion catalysis; S600: After the desorption and regeneration, the high-temperature gas is cooled through a tube-in-tube heat exchanger and then tested. It is then discharged after meeting the emission standards.

2. A VOC catalytic fuel exhaust gas treatment method according to claim 1, characterized in that: In the step S100, particulate matter in the exhaust gas is removed by a dry filter and a cyclone plate tower, and the temperature of the exhaust gas is controlled at 40° C. and the humidity is controlled at 65%-80%.

3. A VOC catalytic fuel exhaust gas treatment method according to claim 1, characterized in that: In the step S200, a multi-unit combined filtering layered adsorption bed is used, wherein the adsorption bed uses honeycomb activated carbon as an adsorbent to adsorb the exhaust gas.

4. A VOC catalytic fuel exhaust gas treatment method according to claim 1, characterized in that: In the step S300, when the adsorbent is fully adsorbed, the gas is heated to 80°C by an electric heater, and desorption is performed by high-temperature gas. The high-concentration organic waste gas after desorption is preheated to 250°C and burned in a catalytic bed. After combustion, the waste gas is decomposed into CO2 and H2O.

5. A VOC catalytic fuel exhaust gas treatment method according to claim 1, characterized in that: In the step S400, the adsorbent is replaced with crushed activated carbon to perform secondary adsorption on the exhaust gas.

6. A VOC catalytic fuel exhaust gas treatment method according to claim 1, characterized in that: In the step S500, the waste gas after the secondary adsorption is heated for the second time, and the secondary desorption and combustion reactions are completed.

7. A VOC catalytic fuel exhaust gas treatment method according to claim 1, characterized in that: In the step S600, the high temperature gas after catalysis is cooled down, and the exhaust gas is tested after cooling down, and discharged into the atmosphere after meeting the emission standards.

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