Device for testing catalytic oxidation performance of vocs

Abstract

This invention relates to the field of catalytic oxidation performance testing technology, and discloses a VOCs catalytic oxidation performance testing device including a gas preparation system, a fixed-bed reactor, a heating system, and a gas chromatograph. The fixed-bed reactor includes at least three sets of reaction tubes, and the heating system is a furnace, with all three sets of reaction tubes located inside the furnace. Each reaction tube includes an outer pipe, an inner pipe, and two connecting flanges. An annular channel is formed between the outer and inner pipes, and the annular channel is connected to the gas preparation system via the connecting flanges. The three independent reaction tubes of this invention support simultaneous or stepwise testing, and a single experiment can complete the comparative analysis of three catalysts, ensuring the consistency of experimental conditions. Furthermore, the leak-proof components (copper outer and inner barriers) combined with the side-pull plate lifting structure innovate the catalyst recovery method from the traditional inverted method to a lifting method, effectively improving the recovery efficiency.

Description

Technical Field

[0001] This invention relates to the field of catalytic oxidation performance testing technology, specifically to a device for testing the catalytic oxidation performance of VOCs. Background Technology

[0002] Catalytic oxidation technology not only effectively avoids secondary pollution at low temperatures and has a short residence time (approximately 0.25 s), but also boasts high purification efficiency. In industrial applications, this technology requires less investment, has a wide range of applications, and is simple to operate. Therefore, it enjoys a very high market share in both domestic and international VOCs treatment technology markets, making it the most efficient and environmentally friendly VOCs treatment technology. In the laboratory, the catalytic performance of the catalyst is evaluated using a fixed-bed microreactor coupled with gas chromatography, with quantitative analysis of reactants and products in the inlet and outlet gases using a gas chromatography-FID detector. The core of this reaction device is the reaction tube within the entire catalytic unit.

[0003] Due to the small inner diameter of the reactor and the presence of a thermocouple in the middle, this device is only suitable for evaluating the performance of small quantities of powdered catalysts, or for testing by pressing the powder into smaller particles. It is difficult to meet the requirements for testing and evaluating the performance of larger particles or larger blocks of catalysts. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a VOCs catalytic oxidation performance testing device, mainly to solve the problem that existing reactors are not convenient for testing catalysts in different states.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A VOCs catalytic oxidation performance testing device includes a gas preparation system, a fixed-bed reactor, a heating system, and a gas chromatograph;

[0007] The fixed-bed reactor includes at least three sets of reaction tubes, and the heating system is a heating furnace, with all three sets of reaction tubes located inside the heating furnace.

[0008] The reaction tube includes:

[0009] The system consists of an outer pipe, an inner pipe, and two connecting flanges. The outer pipe and the inner pipe form an annular channel, which is connected to the gas preparation system via the connecting flanges.

[0010] A base and a top support, wherein a catalyst-containing chamber is formed between the base and the top support;

[0011] A support ring is fixedly installed on the inner circumference of the outer pipe to support the bottom support.

[0012] A heat-conducting part is disposed between the bottom support part and the top support part;

[0013] A thermocouple, wherein the thermocouple is disposed in an inner pipe and the end of the thermocouple is inserted into the space of the receiving chamber.

[0014] As a further embodiment of the present invention,

[0015] The bottom support is made of quartz wool;

[0016] The top support is made of quartz wool.

[0017] The heat-conducting part is quartz sand, which is laid on the upper surface of the lower quartz wool.

[0018] As a further embodiment of the present invention,

[0019] The bottom support is a lower mesh plate, and a lower baffle that abuts against the support ring is fixedly installed at the bottom of the lower mesh plate. A cavity for accommodating quartz wool is formed between the lower baffle and the lower mesh plate.

[0020] The top support is a mesh plate, and an upper cover is fixedly installed on the top of the mesh plate. The upper cover is composed of at least four sets of arc-shaped pieces, with a gap between two adjacent arc-shaped pieces. The arc-shaped pieces and the mesh plate form a cavity for accommodating quartz wool.

[0021] Both the lower mesh plate and the upper mesh plate are provided with through holes for internal pipe clearance;

[0022] The heat-conducting part is a metal heat-conducting component, preferably copper.

[0023] As a further embodiment of the present invention, the metal heat-conducting component comprises multiple sets of heat-conducting rods, which are arranged in a circumferential array along the axis of the lower mesh plate.

[0024] As a further embodiment of the present invention, the metal heat-conducting component is a plurality of heat-conducting arc plates, and the plurality of heat-conducting arc plates are arranged in a circumferential array around the axis of the lower mesh plate.

[0025] As a further embodiment of the present invention, the lower mesh plate is provided with a leak-proof component, the leak-proof component comprising:

[0026] An outer perimeter is fixedly installed on the outer ring of the lower mesh plate, and the top of the outer perimeter abuts against the outer ring of the mesh plate.

[0027] The inner enclosure is fixedly installed in the through hole of the lower mesh plate, and the top of the inner enclosure abuts against the through hole of the upper mesh plate.

[0028] The outer perimeter, inner perimeter, mesh plate, and lower mesh plate form a leak-proof chamber that blocks the catalyst.

[0029] As a further embodiment of the present invention, the outer perimeter, inner perimeter, mesh plate and lower mesh plate are all made of thermally conductive material, namely copper.

[0030] As a further embodiment of the present invention, side pull plates are welded to both sides of the top of the outer perimeter, and clearance openings are provided on both sides of the mesh plate to allow the side pull plates to be positioned.

[0031] As a further embodiment of the present invention, each of the opposite ends of the two side pull plates is provided with a lifting protrusion, and the top of the side pull plate abuts against the inner wall of the connecting flange.

[0032] As a further embodiment of the present invention, the gas preparation system includes an air tank for providing air and a mixing tank for preparing gas, water, toluene, acetone and gas, and a mixing tank for mixing gas, all connected by pipelines. Mass flow meters are installed between the pipelines for preparing gas, water, toluene and acetone and the air tank. An inlet electric valve is installed between the mixing tank and the three sets of reaction tubes. An outlet electric valve is installed between the gas chromatograph and the three sets of reaction tubes.

[0033] Compared with existing technologies, this invention provides a VOCs catalytic oxidation performance testing device with the following advantages: the three independent reaction tubes of this invention support simultaneous or stepwise testing, and a single experiment can complete the comparative analysis of three catalysts, ensuring the consistency of experimental conditions; in addition, the combination of leak-proof components (copper outer and inner baffles) and side-pull plate lifting structure not only improves the uniformity of catalyst heating, but also innovates the catalyst recovery method from the traditional inverted method to the lifting method, effectively improving the recovery efficiency; at the same time, the heat-conducting part formed by copper heat-conducting rods or arc plates achieves uniform heat distribution. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the VOCs catalytic oxidation performance testing device proposed in this invention;

[0035] Figure 2 The VOCs catalytic oxidation performance testing device proposed in this invention Figure 1 A magnified view of a portion of the image;

[0036] Figure 3 This is a schematic cross-sectional view of the reaction tube structure of the VOCs catalytic oxidation performance testing device proposed in this invention;

[0037] Figure 4 This is a schematic diagram of the upper and lower mesh plates of the VOCs catalytic oxidation performance testing device proposed in this invention;

[0038] Figure 5 This is a schematic diagram of the heat-conducting rod structure of the VOCs catalytic oxidation performance testing device proposed in this invention;

[0039] Figure 6 The VOCs catalytic oxidation performance testing device proposed in this invention Figure 5 A schematic diagram of the exploded structure;

[0040] Figure 7 This is a schematic diagram of the thermally conductive arc plate structure of the VOCs catalytic oxidation performance testing device proposed in this invention;

[0041] Figure 8 This is a schematic diagram of the outer ring and inner enclosure structure of the VOCs catalytic oxidation performance testing device proposed in this invention;

[0042] Figure 9 The VOCs catalytic oxidation performance testing device proposed in this invention Figure 8 A schematic diagram of the explosion structure.

[0043] In the diagram: 1. Reaction tube; 2. Inner pipe; 3. Upper quartz wool; 4. Catalyst; 5. Quartz sand; 6. Lower quartz wool; 7. Support ring; 8. Thermocouple;

[0044] 101. External pipe; 102. Connecting flange; 301. Mesh plate; 30101. Upper baffle; 30102. Circumvention opening; 501. Heat-conducting rod; 502. Heat-conducting arc plate; 601. Lower mesh plate; 60101. Lower baffle; 60102. Outer baffle; 60103. Inner baffle; 60104. Side pull plate; 60105. Lifting protrusion. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0046] The component designations used in this document, such as "first" and "second," are merely for distinguishing the described objects and do not have any sequential or technical meaning. The terms "connection" and "linkage" used in this invention, unless otherwise specified, include both direct and indirect connections (linkages). It should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing the invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] Please see Figures 1-9 As shown, the VOCs catalytic oxidation performance testing device includes a gas preparation system, a fixed-bed reactor, a heating system, and a gas chromatograph.

[0049] The gas preparation system includes an air tank for supplying air and a mixing tank for preparing water, toluene, acetone, and gas through pipelines. Mass flow meters are installed between the pipelines for preparing water, toluene, and acetone and the air tank. The mass flow meters are used to monitor and control the output flow of the air tank in real time. The fixed-bed reactor includes at least three sets of reaction tubes 1. The heating system is a heating furnace, and all three sets of reaction tubes 1 are located inside the heating furnace. The heating furnace can heat the three sets of reaction tubes 1. An inlet electric valve is installed between the mixing tank and the three sets of reaction tubes 1. An outlet electric valve is installed between the gas chromatograph and the three sets of reaction tubes 1. Through the cooperation of the inlet and outlet electric valves, the three sets of reaction tubes 1 can be used for different tests.

[0050] Test 1: Catalyst 4 was tested simultaneously in three sets of reaction tubes 1;

[0051] Test 2: Catalyst 4 was tested in each of the three reaction tubes 1.

[0052] Specifically, a schematic diagram of the entire testing setup is shown below. Figure 1 As shown. The catalytic oxidation performance of catalyst 4 for toluene was tested in a fixed-bed microreactor at atmospheric pressure. Reaction tube 1 (e.g.) Figure 2 (As shown) It includes an outer pipe 101, an inner pipe 2, two connecting flanges 102 and a thermocouple 8. The inner pipe 2 is equipped with a thermocouple 8. The heating process is carried out by heating furnace to a specified temperature. At this time, the temperature of the catalyst bed 4 is displayed by thermocouple 8, and then the tail gas is detected by gas chromatograph.

[0053] In this process, the inlet and outlet electric valves of the three sets of reaction tubes 1 work together to meet different catalyst 4 detection requirements. For example, test one can complete a comparative experiment of catalyst 4 testing with different particle sizes.

[0054] The system consists of an outer pipe 101, an inner pipe 2, and two connecting flanges 102. An annular channel is formed between the outer pipe 101 and the inner pipe 2. This annular channel is connected to the gas preparation system via the connecting flanges 102 (which have venting grooves that connect to both the annular channel and the outer pipe). The system also includes a bottom support and a top support. The bottom support is made of lower quartz wool 6, and the top support is made of upper quartz wool 3. A chamber for containing the catalyst 4 is formed between the bottom and top supports. A heat-conducting part, made of quartz sand 5, is located between the bottom and top supports. This heat-conducting part is laid on the upper surface of the lower quartz wool 6. The use of quartz sand 5 in the heat-conducting part not only increases the heat transfer area but also allows for a more uniform distribution of heat within the heating range of the catalyst 4, preventing local overheating or overcooling and thus improving the catalytic oxidation performance and reaction stability of the catalyst 4. Meanwhile, the quartz sand 5 also has good chemical and thermal stability, and can maintain stable performance under high temperature and harsh chemical environment, providing reliable support for the catalyst 4; the support ring 7 is fixedly installed on the inner circumference of the reaction tube 1 to support the bottom support; the thermocouple 8 is installed in the inner pipe 2, and the end of the thermocouple 8 is inserted into the space of the accommodating chamber.

[0055] Specifically, during installation, the outer pipe 101, the inner pipe 2, and the bottom connecting flange 102 are installed first. Then, the thermocouple 8 is inserted into the inner pipe 2. At this time, the upper quartz wool 3 is installed between the outer pipe 101 and the inner pipe 2 until it contacts the support ring 7. At this time, the upper quartz wool 3 is in a loose and taut state, which not only provides support and positioning for the support ring 7, but also allows the upper quartz wool 3 to be installed under the action of friction between itself and the inner wall of the outer pipe 101.

[0056] Then, a layer of quartz sand 5 is laid on the upper quartz wool 3 of the support ring 7, and then the catalyst 4 is laid on the quartz sand 5. At this time, the upper quartz wool 3 is inserted to complete the pressing and sealing of the catalyst 4.

[0057] During the experiment, when the catalyst 4 is in powder form, the upper quartz wool 3 can effectively support the powdered catalyst 4.

[0058] The end of thermocouple 8 extends into the space located at the center of catalyst 4, enabling effective and accurate detection of the temperature of catalyst 4.

[0059] However, after the experiment was completed, during the recovery of catalyst 4, since catalyst 4 and quartz sand 5 were in a mixed state, they were not easy to separate, which increased the difficulty of recovery. Therefore, catalyst 4 was supported by the upper mesh plate 301 and the lower mesh plate 601. Both the lower mesh plate 601 and the upper mesh plate 301 were provided with through holes to avoid the internal pipe 2.

[0060] Specifically, a lower baffle 60101 is fixedly installed at the bottom of the lower mesh plate 601, which abuts against the support ring 7. A chamber for accommodating quartz wool is formed between the lower baffle 60101 and the lower mesh plate 601. The quartz wool in this position can be selected according to the actual state of the catalyst 4 to be tested. If powdered catalyst 4 is selected, quartz wool is still needed to assist the mesh plate 301 and the lower mesh plate 601 for support. If granular catalyst 4 is selected, and the diameter of the granular catalyst 4 is larger than the mesh diameter of the mesh plate 301 and the lower mesh plate 601, then quartz wool can be omitted.

[0061] A top cover 30101 is fixedly installed on the top of the mesh plate 301. The top cover 30101 is composed of at least four sets of arc-shaped pieces, with a gap between two adjacent arc-shaped pieces. The arc-shaped pieces and the mesh plate 301 form a chamber for accommodating quartz wool. Specifically, after the mesh plate 301 seals the catalyst 4, quartz wool is inserted between the four sets of arc-shaped pieces in the top cover 30101. The powdered catalyst 4 is sealed by the quartz wool, and the gap between two adjacent arc-shaped pieces allows part of the quartz wool to contact the inner wall of the outer pipe 101, thereby assisting in the frictional locking of the mesh plate 301.

[0062] The heat-conducting part is a metal heat-conducting component, which is a plurality of heat-conducting rods 501 or heat-conducting arc plates 502. The plurality of heat-conducting rods 501 and heat-conducting arc plates 502 are distributed in a circumferential array below the axis of the mesh plate 601; furthermore, the metal heat-conducting component is preferably copper.

[0063] Specifically, copper has excellent thermal conductivity, which can quickly and evenly transfer heat, ensuring that heat can be effectively conducted to the area where catalyst 4 is located during the VOCs catalytic oxidation performance test, so that catalyst 4 is in a suitable reaction temperature environment, thereby improving the accuracy and stability of the test.

[0064] Multiple sets of heat-conducting rods 501 or heat-conducting arc plates 502 are installed in a circumferential array to ensure that heat is evenly distributed in the surrounding space, avoiding local overheating or overcooling, and further ensuring the uniformity of reaction conditions within the testing device.

[0065] After the catalyst 4 is effectively supported by the lower screen plate 601 and the upper screen plate 301, there is a gap between the lower screen plate 601 and the upper screen plate 301. Therefore, when taking out the catalyst 4, it is necessary to tilt the reaction tube 1 and pour out the catalyst 4, which is a cumbersome operation.

[0066] Therefore, a leak-proof component is provided on the lower mesh plate 601, including an outer perimeter baffle 60102 and an inner perimeter baffle 60103. The outer perimeter baffle 60102 is fixedly installed on the outer ring of the lower mesh plate 601, and the top of the outer perimeter baffle 60102 abuts against the outer ring of the upper mesh plate 301. The inner perimeter baffle 60103 is fixedly installed in the through hole of the lower mesh plate 601, and the top of the inner perimeter baffle 60103 abuts against the through hole of the upper mesh plate 301. Side pull plates 60104 are welded on both sides of the top of the outer perimeter baffle 60102. The upper mesh plate 301 has clearance openings 30102 on both sides to allow the side pull plates 60104 to be positioned. The ends of the opposite sides of the two side pull plates 60104 are provided with lifting protrusions 60105. The top of the side pull plates 60104 abuts against the inner wall of the connecting flange 102.

[0067] Specifically, the outer perimeter baffle 60102, the inner perimeter baffle 60103, the mesh plate 301, and the lower mesh plate 601 form a leak-proof chamber to block the catalyst 4. Therefore, during installation, the catalyst 4 is installed in the leak-proof chamber. After assembling the mesh plate 301, it is installed to the top of the outer pipe 101 through the connecting flange 102, so that the connecting flange 102 presses and blocks the side pull plate 60104, thereby locking the position of the lower mesh plate 601 and the outer perimeter baffle 60102.

[0068] When removing catalyst 4 after testing, simply open the connecting flange 102 and then pull up the side pull plate 60104. At this time, catalyst 4 will be pulled out together with the outer perimeter 60102, the inner perimeter 60103 and the lower mesh plate 601, thus completing the quick removal of catalyst 4.

[0069] It should be noted that the outer baffle 60102, the inner baffle 60103, the mesh plate 301 and the lower mesh plate 601 are all made of thermally conductive material, namely copper. Because copper is used as the thermally conductive material, heat can be quickly and evenly conducted throughout the entire device during the test, making the ambient temperature of the catalyst 4 more stable and consistent.

[0070] This not only helps to improve the efficiency of VOCs catalytic oxidation reaction, but also ensures the stability of the reaction process, reduces the local reaction differences that may be caused by uneven temperature, and thus improves the accuracy and reliability of test results.

[0071] Meanwhile, copper has excellent corrosion resistance, which can resist the erosion of various chemicals during long-term use, extend the service life of the device, and reduce maintenance costs.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A VOCs catalytic oxidation performance testing device, characterized in that, Includes a gas preparation system, a fixed-bed reactor, a heating system, and a gas chromatograph; The fixed-bed reactor includes at least three sets of reaction tubes (1), and the heating system is a heating furnace, with all three sets of reaction tubes (1) located inside the heating furnace; The reaction tube (1) includes: An outer pipe (101), an inner pipe (2) and two connecting flanges (102) are provided. An annular channel is formed between the outer pipe (101) and the inner pipe (2), and the annular channel is connected to the gas preparation system through the connecting flanges (102). A bottom support and a top support, wherein a cavity for receiving the catalyst (4) is formed between the bottom support and the top support; Support ring (7), which is fixedly installed on the inner circumference of the outer pipe (101) to support the bottom support; A heat-conducting part is disposed between the bottom support part and the top support part; Thermocouple (8) is located inside the inner pipe (2), and the end of the thermocouple (8) is inserted into the space of the receiving chamber.

2. The VOCs catalytic oxidation performance testing device according to claim 1, characterized in that, The bottom support is made of lower quartz wool (6). The top support is made of upper quartz wool (3); The heat-conducting part is quartz sand (5), which is laid on the upper surface of the lower quartz wool (6).

3. The VOCs catalytic oxidation performance testing device according to claim 1, characterized in that, The bottom support is a lower mesh plate (601), and a lower baffle (60101) that abuts against the support ring (7) is fixedly installed on the bottom of the lower mesh plate (601). A cavity for accommodating quartz wool is formed between the lower baffle (60101) and the lower mesh plate (601). The top support is a mesh plate (301), and an upper cover (30101) is fixedly installed on the top of the mesh plate (301). The upper cover (30101) is composed of at least four sets of arc-shaped pieces, with a gap between two adjacent arc-shaped pieces. The arc-shaped pieces and the mesh plate (301) form a cavity for accommodating quartz wool. Both the lower mesh plate (601) and the upper mesh plate (301) are provided with through holes to avoid the internal pipe (2); The heat-conducting part is a metal heat-conducting component, and the material of the metal heat-conducting component is copper.

4. The VOCs catalytic oxidation performance testing device according to claim 3, characterized in that, The metal heat-conducting component consists of multiple sets of heat-conducting rods (501), all of which are arranged in a circumferential array around the axis of the lower mesh plate (601).

5. The VOCs catalytic oxidation performance testing device according to claim 3, characterized in that, The metal heat-conducting component consists of multiple sets of heat-conducting arc plates (502), which are arranged in a circumferential array around the axis of the lower mesh plate (601).

6. The VOCs catalytic oxidation performance testing device according to claim 4 or 5, characterized in that, The lower mesh plate (601) is provided with a leak-proof component, which includes: The outer perimeter (60102) is fixedly installed on the outer ring of the lower mesh plate (601), and the top of the outer perimeter (60102) abuts against the outer ring of the upper mesh plate (301); Inner enclosure (60103), the inner enclosure (60103) is fixedly installed in the through hole of the lower mesh plate (601), and the top of the inner enclosure (60103) abuts against the through hole of the upper mesh plate (301); The outer perimeter (60102), inner perimeter (60103), mesh plate (301), and lower mesh plate (601) form a leak-proof chamber that blocks the catalyst (4).

7. The VOCs catalytic oxidation performance testing device according to claim 6, characterized in that, The outer perimeter (60102), inner perimeter (60103), mesh plate (301), and lower mesh plate (601) are all made of thermally conductive material, which is copper.

8. The VOCs catalytic oxidation performance testing device according to claim 6, characterized in that, The outer perimeter (60102) has side pull plates (60104) welded to both sides of its top, and the mesh plate (301) has clearance openings (30102) on both sides to allow the side pull plates (60104) to be positioned.

9. The VOCs catalytic oxidation performance testing device according to claim 8, characterized in that, The two side pull plates (60104) are provided with lifting protrusions (60105) at the ends of their opposite faces, and the top of the side pull plates (60104) abuts against the inner wall of the connecting flange (102).

10. The VOCs catalytic oxidation performance testing device according to claim 8, characterized in that, The gas preparation system includes an air tank for supplying air and a mixing tank for preparing water, toluene, acetone and gas through pipelines. Mass flow meters are installed between the pipelines for preparing water, toluene and acetone and the air tank. An electric inlet valve is installed between the mixing tank and the three sets of reaction tubes (1). An electric outlet valve is installed between the gas chromatograph and the three sets of reaction tubes (1).

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