Dual-adsorption catalytic combustion VOCs exhaust treatment system

Abstract

The utility model discloses a double adsorption formula catalytic combustion VOCS waste gas treatment system, including the filter for the VOCS waste gas and carrying out filtration separation to it still including two activated carbon adsorption box, two zeolite molecular sieve adsorption box, a catalytic combustion furnace and an electric control box, the utility model utilizes the filter to the big particle in the flue gas and carries out physical interception to part water vapor, utilizes activated carbon adsorption box to adsorb the nonpolar or macromolecular VOCS in the flue gas again, utilizes zeolite molecular sieve adsorption box to adsorb the polar or small molecule VOCS in the flue gas finally, and utilizes catalytic combustion furnace to carry out desorption treatment to activated carbon adsorption box and zeolite molecular sieve adsorption box in time, and activated carbon adsorption box and zeolite molecular sieve adsorption box set up two sets respectively to guarantee the uninterrupted operation of flue gas treatment, help to improve the treatment efficiency of waste gas and give consideration to the construction cost, is suitable for the waste gas treatment use of small and medium scale enterprise.

Description

Technical Field

[0001] This utility model relates to the technical field of equipment for industrial waste gas treatment, and in particular to a dual-adsorption catalytic combustion VOCs waste gas treatment system. Background Technology

[0002] VOCs (volatile organic compounds) are widely present in industrial emissions, transportation, and daily life. In particular, VOCs emitted from industries such as coating, printing, petroleum, chemical, and pharmaceutical manufacturing have relatively complex compositions and contain substances such as benzene, hydrocarbons, alcohols, and alkanes. They are not only harmful to the environment and human health, but may also participate in photochemical reactions to form ozone (O3) and fine particulate matter (PM2.5). Therefore, they are a key target for air pollution control and need to be purified before being released into the atmosphere.

[0003] In VOCs treatment processes, desorption is required after the adsorption unit becomes saturated. However, traditional VOCs treatment systems have few treatment units, necessitating the shutdown of the system's air intake before desorption and catalytic combustion. This results in intermittent and unpredictable waste gas treatment, hindering continuous processing and contributing to low efficiency. Using two separate systems to alternately address these issues further exacerbates the cost of waste gas treatment. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a dual adsorption catalytic combustion VOCs waste gas treatment system that can continuously treat waste gas, which helps to improve treatment efficiency and takes into account the investment and construction costs.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is: a dual-adsorption catalytic combustion VOCs waste gas treatment system, including a filter for receiving and separating VOCs waste gas, two activated carbon adsorption boxes, two zeolite molecular sieve adsorption boxes, a catalytic combustion furnace, and an electrical control box. The inlet ends of the two activated carbon adsorption boxes are connected in parallel to the outlet end of the filter. The two activated carbon adsorption boxes are respectively provided with a preliminary desorbed gas output end and a preliminary purified gas output end. The inlet ends of the two zeolite molecular sieve adsorption boxes are respectively connected in parallel to the two preliminary purified gas output ends. At the output end, the two zeolite molecular sieve adsorption boxes are respectively provided with a secondary desorption gas output end and a secondary purification gas output end. The primary desorption gas output end and the secondary desorption gas output end are respectively connected to the catalytic combustion furnace. The secondary purification gas output end and the gas outlet of the catalytic combustion furnace are respectively connected to the external atmospheric environment. Each activated carbon adsorption box and each zeolite molecular sieve adsorption box are also provided with a desorption gas inlet. The desorption gas inlet is connected to a high-temperature desorption gas source, and the high-temperature heat energy of the high-temperature desorption gas source comes from the catalytic combustion furnace.

[0006] As a preferred technical solution, the system also includes a base, wherein the filter, the two activated carbon adsorption boxes, the two zeolite molecular sieve adsorption boxes, the catalytic combustion furnace, and the electrical control box are linearly and sequentially fixed on the base.

[0007] As a preferred technical solution, a centralized exhaust pipe is also included, wherein the two secondary purified gas output ends and the gas outlet end of the catalytic combustion furnace are respectively connected to the centralized exhaust pipe, and the purified gas is discharged into the atmospheric environment through the centralized exhaust pipe.

[0008] As a preferred technical solution, each of the secondary purified gas output terminals is connected to a purified gas collection pipe, the purified gas collection pipe is connected to the centralized exhaust pipe, and a purified gas collection fan is installed on the purified gas collection pipe, the purified gas collection fan is connected to the electrical control box.

[0009] As a preferred technical solution, the catalytic combustion furnace is connected to the activated carbon adsorption box and the zeolite molecular sieve adsorption box through a high-temperature gas supply pipeline and a desorption gas recovery pipeline, respectively, and a desorption purification gas fan is installed on the high-temperature gas supply pipeline, and the desorption purification gas fan is connected to the electrical control box.

[0010] As a preferred technical solution, a maintenance ladder is also fixedly installed on one side of the centralized exhaust pipe.

[0011] As a preferred technical solution, each of the activated carbon adsorption boxes and each of the zeolite molecular sieve adsorption boxes is equipped with a solenoid valve at its inlet and outlet. Each of the activated carbon adsorption boxes and each of the zeolite molecular sieve adsorption boxes is also equipped with a gas detection sensor for detecting gas composition at its purified gas outlet. The solenoid valves and each of the gas detection sensors are connected to the electrical control box.

[0012] As a preferred technical solution, the desorption temperature of the activated carbon adsorption box is 120-150℃.

[0013] As an improvement to the above technical solution, the combustion temperature of the catalytic combustion furnace is 300-400℃.

[0014] Due to the adoption of the above technical solution, this utility model has the following beneficial effects: First, a filter is used to physically intercept large particulate matter and some water vapor in the flue gas; then, an activated carbon adsorption box is used to adsorb non-polar or large molecular VOCs in the flue gas; finally, a zeolite molecular sieve adsorption box is used to adsorb polar or small molecular VOCs in the flue gas; and a catalytic combustion furnace is used to desorb the activated carbon adsorption box and the zeolite molecular sieve adsorption box in a timely manner. Two sets of activated carbon adsorption boxes and zeolite molecular sieve adsorption boxes are set up respectively, so as to ensure uninterrupted flue gas treatment, which helps to improve the treatment efficiency of waste gas while taking into account the investment and construction costs, and is suitable for waste gas treatment of small and medium-sized enterprises. Attached Figure Description

[0015] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the present invention. Wherein:

[0016] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model;

[0017] Figure 2 This is a front view diagram of an embodiment of the present utility model;

[0018] Figure 3 This is a top view schematic diagram of an embodiment of the present utility model;

[0019] Figure 4 This is a schematic diagram of the exhaust gas flow direction in an embodiment of this utility model;

[0020] In the diagram: 1-Filter; 2-Activated carbon adsorption box; 3-Zeolite molecular sieve adsorption box; 4-Catalytic combustion furnace; 5-Electrical control box; 6-Base; 7-Central exhaust pipe; 8-Maintenance ladder; 9-Clean gas collection pipeline; 10-Clean gas collection fan; 11-High temperature gas supply pipeline; 12-Desorbed gas recovery pipeline; 13-Desorbed clean gas fan. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the following detailed description, only certain exemplary embodiments of the present invention are described by way of illustration. Undoubtedly, those skilled in the art will recognize that various modifications can be made to the described embodiments without departing from the spirit and scope of the present invention. Therefore, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

[0022] like Figures 1 to 4As shown, the dual-adsorption catalytic combustion VOCs waste gas treatment system is specifically designed for the efficient treatment of VOCs waste gas. It includes a filter 1 for receiving and separating the VOCs waste gas. Filter 1 is a dry filter and is the first stage of the waste gas treatment system. Specifically, it can be configured as a three-stage progressive filtration system: G4→F5→F7. The G4 stage filter is a coarse filter, typically made of non-woven fabric, metal mesh, or synthetic fibers, capable of intercepting large particles of dust, paint mist, and fibers in the waste gas, achieving a capture rate of over 90% for particles ≥5μm. The F5 stage filter is a medium-efficiency filter, made of glass fiber or electrostatic cotton, further removing fine dust and oil mist from the waste gas, thus preventing clogging of the micropores in subsequent adsorption facilities, achieving a capture rate of 40-60% for particles ≥1μm. The F7 stage filter is a high-to-medium efficiency filter, made of high-density glass fiber or meltblown fabric, achieving a capture rate of 80-90% for particles ≥0.5μm. The above three-stage combination can achieve a filtration efficiency of over 90%, filtering out most of the particulate matter in the flue gas through physical interception and absorbing some moisture to protect the normal operation of downstream equipment.

[0023] This embodiment also includes two activated carbon adsorption boxes 2, two zeolite molecular sieve adsorption boxes 3, a catalytic combustion furnace 4, and an electrical control box 5. The filter 1, the two activated carbon adsorption boxes 2, the two zeolite molecular sieve adsorption boxes 3, the catalytic combustion furnace 4, and the electrical control box 5 are linearly and sequentially fixed on the base 6 to achieve centralized installation of the equipment and a neat and orderly layout. The activated carbon adsorption boxes 2 and the zeolite molecular sieve adsorption boxes 3 form a two-stage dual adsorption mode.

[0024] The system comprises two activated carbon adsorption boxes 2, each containing honeycomb activated carbon. These boxes alternate in their waste gas treatment process, with one in an adsorption state and the other in a desorption state, enhancing the system's capacity and enabling continuous waste gas treatment. The activated carbon adsorption boxes 2 are primarily used to remove non-polar or large molecular VOCs such as benzene and toluene. Through a combination of physical and chemical processes, pollutants are adsorbed and fixed onto the surface of the activated carbon, effectively purifying the waste gas. The desorption process utilizes hot air at a temperature of 120–150°C. The high-concentration waste gas after desorption is then sent to the catalytic combustion furnace 4 for further treatment, ultimately achieving environmentally friendly emissions. Simultaneously, the hot air from the combustion process in the catalytic combustion furnace 4 is recycled and reused for desorption in both the activated carbon adsorption boxes 2 and the zeolite molecular sieve adsorption box 3, achieving energy-saving operation.

[0025] The zeolite molecular sieve adsorption box 3 contains a zeolite molecular sieve, which has excellent adsorption performance and environmental protection characteristics. It works alternately with the activated carbon adsorption box 2. The zeolite molecular sieve inside is mainly used to supplement the adsorption of polar and small molecule VOCs such as ethyl acetate, acetone, and aldehydes, further improving the air purification effect. It works synergistically with activated carbon to remove harmful substances from waste gas. After long-term operation, the zeolite molecular sieve can be periodically regenerated at high temperatures, resulting in a long service life and helping to reduce operating costs.

[0026] The efficient operation of the catalytic combustion furnace 4 relies on precise reaction temperature control. In this embodiment, the combustion temperature of the catalytic combustion furnace 4 is 300–400°C. This temperature range ensures complete combustion of organic matter. The high temperature of the exhaust gas after combustion allows for heat recovery through heat exchange, which can be used for preheating the inlet gas of the catalytic combustion furnace 4, heating the high-temperature gas used for desorption in the activated carbon adsorption box 2 and the zeolite molecular sieve adsorption box 3, etc., to maximize energy utilization and minimize heat emissions. Therefore, utilizing the waste heat from the combustion exhaust gas of the catalytic combustion furnace 4 to preheat the air or gas entering the furnace not only improves energy efficiency but also helps reduce the overall system's energy consumption and operating costs. To ensure the safety of the catalytic combustion process, the catalytic combustion furnace 4 is also equipped with several conventional safety facilities, including explosion-proof valves, flame arresters, and temperature / concentration interlock alarm devices, to prevent fire or explosion risks due to abnormal conditions and ensure the safety of equipment and personnel. In addition, the catalytic combustion furnace 4 can use a platinum-palladium metal catalyst, which has high catalytic activity and can effectively promote the oxidation reaction of VOCs with oxygen to ultimately produce harmless carbon dioxide and water.

[0027] Specifically, the inlet ends of the two activated carbon adsorption boxes 2 are connected in parallel to the outlet end of the filter 1. Each of the two activated carbon adsorption boxes 2 is provided with a preliminary desorption gas output end and a preliminary purification gas output end. The inlet ends of the two zeolite molecular sieve adsorption boxes 3 are connected in parallel to the two preliminary purification gas output ends. Each of the two zeolite molecular sieve adsorption boxes 3 is provided with a secondary desorption gas output end and a secondary purification gas output end. The preliminary desorption gas output end and the secondary desorption gas output end are respectively connected to the catalytic combustion furnace 4. The secondary purification gas output end and the outlet end of the catalytic combustion furnace 4 are respectively connected to the external atmospheric environment. All connections are achieved through pipelines. Each activated carbon adsorption box 2 and each zeolite molecular sieve adsorption box 3 is also provided with a desorption inlet. The desorption inlet is connected to a high-temperature desorption gas source, and the high-temperature heat energy of the high-temperature desorption gas source comes from the catalytic combustion furnace 4.

[0028] Each activated carbon adsorption box 2 and each zeolite molecular sieve adsorption box 3 is equipped with a solenoid valve at its inlet and outlet. Each activated carbon adsorption box 2 and each zeolite molecular sieve adsorption box 3 is also equipped with a gas detection sensor at its purified gas outlet for detecting gas composition. The solenoid valves and the gas detection sensors are connected to the electrical control box 5. Each box and the catalytic combustion furnace 4 are also equipped with conventionally installed temperature sensors, pressure sensors, safety valves, etc., to ensure the safe operation of the system. The electrical control box 5, through the cooperation of the sensors, comprehensively detects temperature changes and key parameter changes in various important components of the system to ensure the stable, efficient, and safe operation of the catalytic combustion furnace 4 for combustion catalysis, heat exchange, and heat storage. Based on the detection data from the gas detection sensors, the electrical control box 5 controls the corresponding solenoid valve switching actions to adjust the gas flow path and complete the alternating switching between the two activated carbon adsorption boxes 2 and the two zeolite molecular sieve adsorption boxes 3.

[0029] In this embodiment, a centralized exhaust pipe 7 is provided on the outer side of the base 6. The two secondary purified gas output ends and the gas outlet of the catalytic combustion furnace 4 are respectively connected to the centralized exhaust pipe 7, and the purified gas is discharged into the atmosphere through the centralized exhaust pipe 7. A maintenance ladder 8 is also fixedly installed on one side of the centralized exhaust pipe 7 to facilitate access for maintenance operations.

[0030] Each of the secondary purified gas output terminals is connected to a purified gas collection pipe 9, which is connected to the centralized exhaust pipe 7. A purified gas collection fan 10 is installed on the purified gas collection pipe 9 and connected to the electrical control box 5. Under the action of the purified gas collection fan 10, the purified gas after system treatment is rapidly discharged. The catalytic combustion furnace 4 is connected to the activated carbon adsorption box 2 and the zeolite molecular sieve adsorption box 3 through a high-temperature gas supply pipe 11 and a desorption gas recovery pipe 12, respectively. A desorption purified gas fan 13 is installed on the high-temperature gas supply pipe 11 and connected to the electrical control box 5. Since the desorption purified gas fan 13 is used to deliver high-temperature desorbed gas to each box, it is required to withstand high temperatures.

[0031] This embodiment has the following advantages:

[0032] 1. The combination of activated carbon and zeolite molecular sieves can cover both polar and non-polar VOCs, providing a wide coverage and making it particularly suitable for treating complex flue gas, with a removal rate of over 95%.

[0033] 2. The catalytic combustion furnace described above can completely decompose organic matter, so that the emission concentration can be stably reduced to <30mg / m³.

[0034] 3. The activated carbon adsorption box and the zeolite molecular sieve adsorption box can form a dual desorption mode at high and low temperatures, which extends the service life. The heat generated during the desorption process can be recovered and reused, resulting in low operating and maintenance costs.

[0035] 4. The ratio of activated carbon to zeolite molecules can be adjusted according to the composition characteristics of the waste gas, thereby controlling operating costs. It is highly flexible and more economical and practical.

[0036] The description of this utility model is given for illustrative and descriptive purposes only, and is not intended to be exhaustive or to limit the utility model to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the utility model, and to enable those skilled in the art to understand the utility model and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A dual-adsorption catalytic combustion VOCs waste gas treatment system, comprising a filter for receiving and separating VOCs waste gas, characterized in that: It also includes two activated carbon adsorption boxes, two zeolite molecular sieve adsorption boxes, a catalytic combustion furnace, and an electrical control box. The inlet ends of the two activated carbon adsorption boxes are connected in parallel to the outlet end of the filter. The two activated carbon adsorption boxes are respectively provided with a preliminary desorption gas output end and a preliminary purification gas output end. The inlet ends of the two zeolite molecular sieve adsorption boxes are respectively connected in parallel to the two preliminary purification gas output ends. The two zeolite molecular sieve adsorption boxes are respectively provided with a secondary desorption gas output end and a secondary purification gas output end. The preliminary desorption gas output end and the secondary desorption gas output end are respectively connected to the catalytic combustion furnace. The secondary purification gas output end and the outlet end of the catalytic combustion furnace are respectively connected to the external atmospheric environment. Each activated carbon adsorption box and each zeolite molecular sieve adsorption box are also provided with a desorption gas inlet. The desorption gas inlet is connected to a high-temperature desorption gas source, and the high-temperature heat energy of the high-temperature desorption gas source comes from the catalytic combustion furnace.

2. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 1, characterized in that: It also includes a base, and the filter, the two activated carbon adsorption boxes, the two zeolite molecular sieve adsorption boxes, the catalytic combustion furnace and the electrical control box are linearly and sequentially fixed on the base.

3. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 1, characterized in that: It also includes a centralized exhaust pipe, through which the two secondary purified gas output ends and the gas outlet end of the catalytic combustion furnace are respectively connected to the centralized exhaust pipe, and the purified gas is discharged into the atmospheric environment.

4. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 3, characterized in that: Each of the secondary purified gas output terminals is connected to a purified gas collection pipe, which is connected to the centralized exhaust pipe. A purified gas collection fan is installed on the purified gas collection pipe and is connected to the electrical control box.

5. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 1, characterized in that: The catalytic combustion furnace is connected to the activated carbon adsorption box and the zeolite molecular sieve adsorption box through a high-temperature gas supply pipeline and a desorption gas recovery pipeline, respectively. A desorption purification gas fan is installed on the high-temperature gas supply pipeline, and the desorption purification gas fan is connected to the electrical control box.

6. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 3, characterized in that: A maintenance ladder is also fixedly installed on one side of the centralized exhaust pipe.

7. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 1, characterized in that: Each activated carbon adsorption box and each zeolite molecular sieve adsorption box is equipped with a solenoid valve at its inlet and outlet. Each activated carbon adsorption box and each zeolite molecular sieve adsorption box is also equipped with a gas detection sensor for detecting gas composition at its purified gas outlet. The solenoid valve and each gas detection sensor are connected to the electrical control box.

8. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 1, characterized in that: The desorption temperature of the activated carbon adsorption box is 120–150°C.

9. The dual-adsorption catalytic combustion VOCs waste gas treatment system as described in claim 1, characterized in that: The combustion temperature of the catalytic combustion furnace is 300-400℃.

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