A skid-mounted gas purification device for catalytic degradation of toluene

Abstract

The utility model relates to the field of toluene catalytic degradation, specifically relates to a kind of pry dress formula catalytic degradation toluene's gas purification device, including pry dress base, cover is equipped with the cover body in pry dress base upper, and the function unit integrated in pry dress base and located in cover body, the function unit includes: gas path control and gas mixing unit, for adjusting and mixing toluene waste gas and co-reaction gas;Catalytic reaction unit, with the gas path control and gas mixing unit communication, it is filled with CTO catalyst in, for catalytic degradation toluene under 245~350 ℃.The utility model is suitable for the dispersion scene of smaller air volume, such as workshop, printing and dyeing workshop and small industrial emission source etc., compared with the mode such as heat accumulation combustion treatment toluene, pry dress formula purification device and its application can reach the characteristics of high purification efficiency, low energy consumption, no secondary pollution, high safety, it is convenient to use in the flexible movement between multiple scenes, high cost performance.

Description

Technical Field

[0001] This utility model relates to the field of toluene catalytic degradation, specifically to a skid-mounted gas purification device for catalytic degradation of toluene. Background Technology

[0002] With the development of industrial manufacturing, such as coating, printing, chemical and pharmaceutical synthesis, the emission of volatile organic compounds (VOCs) continues to increase. Toluene, as a typical aromatic hydrocarbon VOC solvent or chemical, is characterized by its high stability and difficulty in degradation. It not only irritates the human respiratory and nervous systems, but long-term exposure may also lead to chronic poisoning. Furthermore, it is a significant precursor to ozone pollution and PM2.5, posing a dual threat to the ecological environment and human health. Currently, the mainstream VOC treatment technologies in many related industries mainly include adsorption, absorption, and regenerative thermal oxidizer (RTO). Among these, adsorption and absorption methods, such as the application of a hydrophobic ionic liquid-embedded hypercrosslinked polymer and its preparation method in CN119978401A for the selective adsorption of toluene vapor, rely on the physical adsorption of VOCs by adsorbents such as activated carbon. However, adsorbents are easily saturated, requiring frequent regeneration or replacement, posing a risk of secondary pollution. Moreover, the treatment efficiency drops sharply for high concentrations of toluene, and material regeneration consumes a lot of energy.

[0003] Absorption methods separate VOCs by dissolving them in solvents, as illustrated in CN115888331A, which describes a VOCs absorbent, its preparation method, application, and regeneration method. However, these methods consume large amounts of solvent, have high regeneration costs, and exhibit poor selectivity for low-polarity VOCs like toluene, making it difficult to meet long-term stable purification requirements. Furthermore, absorbent regeneration requires distillation for reheating, increasing energy consumption, and the components are prone to oxidation and deterioration, necessitating replacement every few months, resulting in high annual maintenance costs.

[0004] Regenerative Thermal Oxidizer (RTO) technology introduces VOCs into a high-temperature (800-1200℃) combustion chamber for oxidation and decomposition, utilizing a heat storage medium to recover heat from the flue gas and achieve energy savings. However, RTOs have inherent drawbacks: First, the equipment is bulky, requiring large heat storage and combustion chambers, making it only suitable for large-scale centralized VOC treatment scenarios and unable to meet the purification needs of small, scattered scenarios, such as printing workshops. Second, the process is energy-intensive, requiring continuous fuel replenishment during high-temperature combustion, while also incurring significant heat losses; especially for low-concentration toluene, the heat consumption far exceeds the energy released by VOC oxidation, resulting in high operating costs. Third, there are significant safety risks; toluene can undergo incomplete combustion at high temperatures, producing CO or other toxic byproducts, and the high-temperature state of the heat storage medium can easily cause fire hazards. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a skid-mounted gas purification device for the catalytic degradation of toluene. Compared to devices and methods such as regenerative thermal oxidizers (RTO) for treating toluene, this skid-mounted purification device and its application offer advantages such as high purification efficiency, low energy consumption, no secondary pollution, high safety, flexible mobility across various scenarios, and high cost-effectiveness; ultimately, it achieves highly efficient catalytic purification of toluene waste gas. This invention achieves its purpose as follows: A skid-mounted gas purification device for the catalytic degradation of toluene includes a skid-mounted base, a cover over the skid-mounted base, and a functional unit integrated into the skid-mounted base and located within the cover. The functional unit includes: Gas path control and mixing unit, used to regulate and mix toluene waste gas and co-reaction gas; A catalytic reaction unit, connected to the gas path control and mixing unit, is filled with a CTO catalyst for catalytic degradation of toluene at 245–350°C. A circuit and temperature control unit is used to power the device and control the reaction temperature of the catalytic reaction unit; A bypass pipeline unit is connected in parallel between the inlet and outlet of the catalytic reaction unit to guide gas flow in abnormal situations. The exhaust pipe unit is connected to the catalytic reaction unit and is used to discharge the exhaust gas after the reaction.

[0006] The skid-mounted base is made of lightweight aluminum alloy, stainless steel, or carbon steel with a rust-proof coating. It has multiple lockable casters at the bottom. The cover is a detachable aluminum alloy cover with ventilation holes on the top and left side. The rear side has an inspection opening and a sealing cover that matches the inspection opening.

[0007] The gas path control and mixing unit includes a toluene waste gas inlet pipe, a co-reaction gas inlet pipe, flow meters and regulating valves respectively installed on the toluene waste gas inlet pipe and the co-reaction gas inlet pipe, and a gas mixing pipe located downstream of the two inlet pipes to ensure that the toluene waste gas and the co-reaction gas are fully mixed.

[0008] The catalytic reaction unit includes a catalytic reaction tube, a heating element and an insulation layer fitted outside the catalytic reaction tube, and a CTO catalyst filling layer filled inside the catalytic reaction tube.

[0009] The bypass valve of the bypass pipeline unit is an electromagnetic control valve, which is electrically connected to the circuit and temperature control unit. When the reaction temperature of the catalytic reaction unit is abnormal, the circuit and temperature control unit sends a control signal to the electromagnetic control valve, causing the electromagnetic control valve to open automatically and realize gas bypass flow.

[0010] The exhaust pipe unit includes an exhaust pipe body, a branch pipe, and a vent pipe; one end of the branch pipe is connected to the exhaust pipe body, and the other end is provided with an exhaust gas sampling interface; the vent pipe is connected to one end of the catalytic reaction unit outlet through the exhaust pipe body, and exhaust gas sampling is achieved through the branch pipe, while exhaust gas from the catalytic reaction is vented through the vent pipe.

[0011] The circuit includes a power module that provides operating power; a temperature sensing element installed on the outer wall of the catalytic reaction tube, with its detection end corresponding to the middle area of ​​the catalyst packing layer, for detecting temperature; a temperature controller connected to the temperature sensing element for receiving temperature signals and outputting control commands; and a heating element located outside the catalytic reaction tube, whose on / off state is controlled by the output command of the temperature controller to maintain the reaction temperature between 245 and 350°C. The circuit and temperature control unit also include a timing control element, which, in conjunction with the temperature controller, controls the on / off state of the electromagnetic control switch.

[0012] The catalytic material of the CTO catalyst filling layer is any one of the following: alumina-supported platinum-based CTO catalyst, promoter-supported silver-based CTO catalyst, or non-precious metal-based CTO catalyst composed of transition metal oxides.

[0013] The treatment of toluene waste gas includes the following unit steps: DB1: Waste gas mixing and blending. The toluene waste gas to be treated is introduced into the gas path control and mixing unit of the device and mixed with the co-reaction gas, such as dry air. The mixing ratio is adjusted by the flow meter and regulating valve to make the toluene concentration in the mixed waste gas uniform and stable at about 300-3000 PPM. DB2: Gas space velocity setting. The gas space velocity of the mixed waste gas in the device is set to 3000-150000 L / kg / h through the flow meter and regulating valve to match the gas space velocity requirements of the catalytic reaction unit. DB3: Catalytic unit temperature control, the circuit and temperature control unit of the start-up device are used to coordinate the on and off of the heating element; the temperature inside the catalytic reaction unit is detected in real time by the temperature sensing element, and the electromagnetic control switch is controlled by the temperature controller in combination with the timing control element to drive the heating element to gradually raise the temperature of the catalytic reaction unit from room temperature to 245-350°C, and maintain a constant temperature in this temperature range, such as 280°C. DB4: Catalytic degradation of toluene. The mixed waste gas with the set space velocity in step DB2 is introduced into the catalytic reaction unit so that the mixed waste gas can fully contact the catalyst packing layer in the unit and achieve full catalytic degradation of toluene at the given reaction temperature. DB5: Exhaust gas analysis and venting pipeline. The exhaust gas after catalytic degradation enters the exhaust pipeline unit, and the residual concentration of toluene in the exhaust gas is monitored in real time to calculate the degradation rate. The toluene degradation rate is monitored in real time through the detection module. Generally, when the degradation rate is ≥85%, it is considered to be relatively complete degradation. It is directly vented through the venting main pipe.

[0014] In step DB1, the toluene concentration in the mixed waste gas is adjusted to 300-3000 PPM; In step DB2, the gas space velocity is set to 3000-150000 L / kg / h; In step DB3, the temperature of the catalytic reaction unit is controlled at 245–350℃; when the reaction temperature is 270–280℃, the catalytic degradation rate of toluene is ≥90%; when the catalytic reaction temperature is 290–330℃, the degradation rate of toluene is ≥95%; the energy consumption of the whole process is significantly reduced compared with the energy consumption of traditional regenerative thermal oxidizer (RTO) technology and equipment. The non-noble metal-based CTO catalyst, composed of manganese-copper-based transition metal oxides, used in the catalyst filling layer is prepared by the following steps: Precursor mixing: Potassium permanganate and copper acetate are mixed evenly in a dry powder mixer, wherein the molar ratio of Mn:Cu is 2:1 to 10:1; Self-propagating reaction: The homogeneous mixture is spread evenly on a glass plate and ignited with an electronic igniter. After a few seconds of reaction, crude manganese-copper based catalyst is obtained. Impurity removal and drying: The crude manganese copper-based catalyst is washed with water and filtered to obtain the filter cake of the manganese copper-based catalyst precursor. The filter cake is then dried in an oven at 100°C for 12 hours to obtain a non-precious metal-based CTO catalyst composed of manganese copper-based transition metal oxides for the catalytic degradation of toluene.

[0015] Based on extensive design, device fabrication, catalytic application, and optimization practices, this invention provides a skid-mounted device system through a compact layout of circuit control and temperature control units, a skid-mounted base, universal control, a cover mounted on the skid-mounted base, and functional units integrated into the skid-mounted base and located within the cover: a gas path control and mixing unit, a catalytic reaction unit, a bypass pipeline unit, and a catalytic exhaust gas unit. This system achieves integrated and flexibly mobile high-efficiency application. Simultaneously, the precise regulation of the gas path control and mixing unit, combined with the uniform heating and airflow distribution of the catalytic reaction tube, ensures a stable purification process for the efficient catalytic degradation of toluene. The bypass pipeline unit's complementary switching between the gas path and exhaust pipeline units enhances safety and reliability in multiple ways. Ultimately, through structural design and functional synergy, this device fills the gaps or deficiencies in technology and equipment for decentralized, small-volume toluene purification scenarios. Compared to traditional regenerative thermal oxidizer (RTO) devices for toluene degradation, the skid-mounted device designed and manufactured in this work offers advantages in degradation efficiency, energy consumption, skid-mounted structure, integrated and reduced volume, and safety.

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the gas mixing tube. Figure 3 This is a schematic diagram of the catalytic reaction tube. Figure 4 This is a schematic diagram of the circuit control and temperature control of the temperature control module; 1 is the skid-mounted base; 2 is the enclosure; 4 is the gas path control and mixing unit; 5 is the catalytic reaction unit; 6 is the circuit and temperature control unit; 7 is the bypass pipeline unit; 8 is the exhaust pipeline unit; 14 is the toluene exhaust gas inlet pipe; 15 is the co-reactant gas inlet pipe; 16 is the gas flow meter; 17 is the regulating valve; 18 is the gas mixing pipe; 19 is the catalytic reaction pipe; 20 is the heating and insulation layer; 21 is the CTO catalyst filling layer; 22 is the bypass valve; 23 is the exhaust pipeline body; 24 is the branch pipe; 25 is the main vent pipe; 26 is the exhaust gas sampling interface; 27 is the power module; 28 is the temperature sensing element; 29 is the temperature controller; 30 is the heating element; 31 is the timing control element; 32 is the electromagnetic control switch. Detailed Implementation

[0018] Referring to the accompanying drawings, the specific embodiments of this utility model will be described in detail.

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] See Figures 1-4 An embodiment of a skid-mounted gas purification device for catalytic degradation of toluene includes a skid-mounted base 1, a cover 2 mounted above the skid-mounted base 1, and functional units integrated into the skid-mounted base 1 and located within the cover 2. The base can be made of Q235 carbon steel and has dimensions of 1m × 0.8m × 0.9m. The functional units include a gas path control and mixing unit 4, a catalytic reaction unit 5, a circuit and temperature control unit 6, a bypass pipeline unit 7, and an exhaust pipeline unit 8, wherein: Gas path control and mixing unit 4 is used to regulate and mix toluene waste gas and co-reaction gas; The catalytic reaction unit 5 is connected to the gas path control and mixing unit 4, and is filled with a CTO catalyst for catalytic oxidation (combustion) for catalytic degradation of toluene at 245-350°C. The circuit and temperature control unit 6 is used to power the device and control the reaction temperature of the catalytic reaction unit 5. Bypass pipeline unit 7 is connected in parallel between the inlet and outlet of the catalytic reaction unit 5 and is used to guide gas in abnormal situations; The exhaust pipe unit 8 is connected to the catalytic reaction unit 5 and is used to discharge the exhaust gas after the reaction.

[0021] The skid-mounted design integrates multiple unit system devices onto a single base, forming an independent module that facilitates design, manufacturing, transportation, and installation. The skid-mounted base 1 can be equipped with multiple wheels or lifting points, allowing for easy movement to multiple work locations, suitable for temporary operations, multi-location operations, or situations requiring rapid deployment. In this embodiment, the cover 2 is made of aluminum alloy or 304 stainless steel, and is a detachable aluminum alloy metal cover. Ventilation holes are provided on the top and left side walls, and an inspection opening and matching sealing cover are provided on the rear. An operation panel is located on the front of the cover 2, and an inspection door is located on the rear, which is fixedly connected to the cover 2 with bolts. At least four locking casters are evenly distributed at the bottom of the skid-mounted base 1. Each caster includes a mounting base bolted to the base, a wheel bracket rotatably connected to the mounting base via a vertical pivot, and a rubber roller rotatably mounted on the bottom of the wheel bracket. A manual locking lever is provided on the side of the wheel bracket; pressing it engages the outer surface of the rubber roller to restrict rotation, while releasing it disengages the lock, facilitating flexible device movement.

[0022] In some embodiments, the catalytic reaction unit 5 includes a catalytic reaction tube 19, a heating element and an insulation layer 20 sleeved outside the reaction tube 19, and a CTO catalyst filling layer 21 filled inside the catalytic reaction tube 19. The catalytic reaction tube is provided with a CTO catalyst filling layer 21, and CTO catalyst support layers are provided upstream and downstream of the CTO catalyst filling layer 21.

[0023] Integrating heating with the catalytic reaction eliminates the need for separate preheating or catalytic chambers. Its compact structure makes it suitable for dispersed environments with low airflow, such as workshops, dyeing plants, and small industrial emission sources. Compared to regenerative combustion methods for toluene treatment, this skid-mounted purification device and its applications offer advantages such as high purification efficiency, low energy consumption, high safety, and flexible mobility across various scenarios. The heating element encasing the catalytic reaction tube ensures relatively uniform radial heating, preventing insufficient catalytic oxidation of the raw materials due to localized low temperatures or deactivation of the CTO catalyst due to excessively high temperatures. The CTO catalyst support layer both fixes the CTO catalyst particles and evenly distributes the airflow, ensuring uniform passage of exhaust gas through the CTO catalyst filling layer 21. This prevents insufficient contact time or carbon buildup caused by excessively fast or slow localized airflow. The heating element directly heats the CTO catalyst filling layer 21, resulting in low heat loss. The multi-layered structure provides insulation, reducing environmental heat dissipation, shortening start-up heating time, and requiring only minor supplemental heating to maintain a reaction temperature of 245–350℃ during stable operation. The catalytic reaction tube integrates a CTO catalyst filling layer 21 and a support layer, realizing the integration of heating, catalysis and gas path constraint, overcoming the problems of large size and low thermal efficiency of traditional devices.

[0024] In some embodiments, the gas path control and mixing unit 4 includes a toluene waste gas inlet pipe 14, a co-reactant gas inlet pipe 15, flow meters 16 and regulating valves 17 respectively installed on the toluene waste gas inlet pipe 14 and the co-reactant gas inlet pipe 15, and a mixing pipe 18 located downstream of the two pipes. The mixing pipe 18 can be filled with glass beads to ensure that the toluene waste gas and the co-reactant gas are fully mixed. With two independently controlled gas inlets, the toluene waste gas enters through the toluene waste gas inlet pipe 14, and the co-reactant gas / combustion air enters through the co-reactant gas inlet pipe 15. After being combined through a three-way valve, they enter the mixing pipe 18 for pre-mixing and then enter the catalytic reaction pipe 19. This avoids problems such as CTO catalyst activity decay, uneven mixing, or incomplete oxidation of toluene due to insufficient local oxygen concentration caused by the inability to adjust the inlet gas concentration. With the help of the regulating valves 17 and flow meters 16 on the two pipes, the ratio of co-reactant gas can be adjusted as needed to stabilize the toluene concentration within the optimal activity range of the CTO catalyst, thereby solving the problems of poor adaptability to concentration fluctuations and unstable degradation rate in traditional devices.

[0025] In some embodiments, the bypass valve of the bypass pipeline unit 7 is a bypass valve 22, which can be an electromagnetic control valve and electrically connected to the circuit and temperature control unit 6. When the catalytic reaction unit 5 experiences abnormal temperature, abnormal pressure, or a decrease in CTO catalyst activity, the circuit and temperature control unit 6 sends a signal to the bypass valve 22 to automatically open the bypass pipeline and achieve gas diversion. The exhaust gas can be switched to the bypass pipeline and temporarily introduced into a backup treatment unit such as an adsorption or detection device. At the same time, it facilitates the detection and monitoring of the mixing effect and the toluene concentration before catalysis. When a sudden increase in toluene concentration, excessive tail gas, or excessively high reaction temperature is detected, the gas path switching of the bypass pipeline can be quickly opened, and the high-concentration exhaust gas can be diverted to the bypass pipeline through a three-way valve to reduce the load on the catalytic reaction tube 19, avoid local overheating of the reactor caused by a sudden increase in oxidation exothermic heat, prevent CTO catalyst deactivation, provide active overheat protection for the device, and solve the problems of lack of risk control measures and poor safety in traditional RTO devices.

[0026] In some embodiments, the exhaust pipe unit 8 includes an exhaust pipe body 23, a branch pipe 24, and a vent pipe 25; one end of the branch pipe 24 is connected to the exhaust pipe body 23, and the other end is provided with an exhaust gas sampling interface 26; the vent pipe 25 is connected to one end of the outlet of the catalytic reaction unit 5 through the exhaust pipe body 23, and exhaust gas sampling is realized through the branch pipe 24, and exhaust gas from the catalytic reaction is vented through the vent pipe 25.

[0027] The two exhaust paths can be adapted to direct exhaust emission, exhaust detection, or emergency exhaust emission scenarios, and can also be connected to an adsorption module or detection device for further use in waste heat recovery scenarios. When the exhaust gas emitted from the catalytic converter 19 does not meet the standards, or when it is necessary to reduce the load on the catalytic converter 19, one of the exhaust pipes can be connected to avoid direct external emission. By immediately switching to the other exhaust pipe, the problem of unit shutdown caused by failure of the traditional single exhaust channel can be avoided. At the same time, the coordination of upstream and downstream valves can realize independent control of the bypass pipeline exhaust and the exhaust of the catalytic converter 19, further improving the flexibility and operational stability of the unit's gas path control.

[0028] In some embodiments, the circuit and temperature control unit 6 includes a power module 27, a temperature sensing element 28, a temperature regulator 29, and a heating element 30, and the functions of each component are as follows: The power module 27 provides operating power; the temperature sensing element 28 is installed on the outer wall of the catalytic reaction tube 19, and its detection end corresponds to the middle area of ​​the catalyst filling layer 21, for detecting temperature; the temperature controller 29 is connected to the temperature sensing element 28, for receiving temperature signals and outputting control commands; the heating element 30 is disposed outside the catalytic reaction tube 19, and its on / off state is controlled by the output command of the temperature controller 29 to maintain the reaction temperature at 245-350°C. The circuit and temperature control unit 6 also includes a timing control element 31, which is used by the temperature controller 29 in conjunction with the timing control element 31 to control the on / off state of the electromagnetic control switch 32.

[0029] This invention also provides a method for applying the skid-mounted gas purification device for catalytic degradation of toluene as described in any of the above embodiments.

[0030] Example 1

[0031] (1) Waste gas mixing and preparation: The toluene waste gas to be treated is introduced into the gas path control and mixing unit 4 of the device and mixed with the co-reaction gas, such as dry air. The mixing ratio is adjusted by the flow meter 16 and the regulating valve 17 to control the inlet flow rate of toluene waste gas to 900L / h and the inlet flow rate of air to 3600L / h (the total gas flow rate is maintained at 4500L / h) so that the toluene concentration in the mixed waste gas is stabilized at 500PPM. (2) Gas space velocity setting: The total gas space velocity of the mixed waste gas in the device is set to 30000 L / kg / h by the coordinated control of the flow meter 16 and the regulating valve 17, combined with the filling amount of 150 ml (150 g) of Mn:Cu=10:1 manganese copper-based catalyst in the catalytic reaction unit 5, in order to meet the reaction requirements of the catalytic reaction unit 5. (3) Temperature control of catalytic unit: The circuit and temperature control unit 6 of the opening device are used to control the on and off of the heating element (30) in a coordinated manner. The temperature inside the catalytic reaction unit 5 is detected in real time by the temperature sensing element 28. The temperature controller 29, combined with the timing control element 31, controls the on and off of the electromagnetic control switch 32, driving the heating element 30 to gradually raise the temperature of the catalytic reaction unit 5 from room temperature to 300°C at a heating rate of 5°C / min, and maintaining the catalytic reaction temperature at 300°C. (4) Catalytic degradation of toluene: The mixed waste gas with the space velocity set in step (2) is introduced into the catalytic reaction unit 5 so that the mixed waste gas and the catalyst filling layer 21 in the unit are in full contact at the given reaction temperature of 280-320℃; after the catalytic degradation reaction occurs, the toluene is fully catalytically degraded. (5) Exhaust gas analysis and venting: The degraded exhaust gas enters the exhaust pipeline unit 8. The remaining toluene concentration is monitored in real time by the detection module in the unit, and the toluene degradation rate is calculated. The sampling interface is used to detect once every hour. The monitoring results show that the toluene degradation rate is ≥92% at 300℃, the inlet concentration is 500PPM, and the outlet concentration meets the standard, which meets the emission requirements of degradation rate ≥85%-90%. The exhaust gas is directly vented through the venting main pipe 25. The total energy consumption of the whole process is reduced by more than 30-45% compared with the traditional RTO technology. (6) Adjustment of reaction temperature and verification of the effect of catalytic degradation of toluene: Repeat steps (3) to (5), adjust the temperature of catalytic reaction unit 5 to 320℃ and maintain it, while keeping other conditions unchanged. The detection module shows that the toluene degradation rate is ≥96% and the outlet concentration meets the standard. It runs continuously for 36 hours, and records data once every 6 hours. The catalytic degradation rate is stable. The heating element operates stably without fluctuation.

[0032] Example 2

[0033] (1) Waste gas mixing and adjustment: The toluene waste gas to be treated is introduced into the gas path control and mixing unit 4 of the device and mixed with the co-reaction gas, such as dry air. The mixing ratio is adjusted by the flow meter 16 and the regulating valve 17 to control the inlet flow rate of toluene waste gas to 900L / h and the inlet flow rate of air to 3600L / h, and the total gas flow rate is maintained at 4500L / h, so that the toluene concentration in the mixed waste gas is stabilized at 500PPM. (2) Gas space velocity setting: The gas space velocity of the mixed waste gas in the device is set to 30000 L / kg / h by the coordinated control of the flow meter 16 and the regulating valve 17, combined with the filling amount of 150 ml of Mn:Cu=7.5:1 manganese copper-based catalyst in the catalytic reaction unit 5, in order to meet the reaction requirements of the catalytic reaction unit 5. (3) Temperature control of the catalytic unit: The circuit and temperature control unit 6 of the device are turned on. The temperature of the catalytic reaction unit 5 is detected in real time by the temperature sensing element 28. The temperature controller 29, combined with the timing control element 31, controls the on and off of the electromagnetic control switch 32, and drives the heating element 30 to gradually raise the temperature of the catalytic reaction unit 5 from room temperature to 300°C at a heating rate of 5°C / min, and stabilize it at 300°C. (4) Catalytic degradation of toluene: The mixed waste gas with the space velocity set in step (2) is introduced into the catalytic reaction unit 5 so that the mixed waste gas can fully contact the catalyst filling layer 21 in the unit and a catalytic reaction occurs to achieve catalytic degradation of toluene; (5) Exhaust gas analysis and venting: The degraded exhaust gas enters the exhaust pipe unit 8, and the toluene degradation rate is monitored in real time by the detection module in the unit. The monitoring results show that the toluene degradation rate is ≥90% at 300℃ and the outlet concentration is ≤50PPM, which meets the emission requirements of degradation rate ≥85-90%. The exhaust gas is directly vented through the venting main pipe 25. The temperature at which the degradation rate of 90% is reached is 65℃ lower than that of pure MnO2 catalyst (requiring 365℃). The catalytic degradation performance is stable after 72 hours of continuous operation. (6) Temperature adjustment and degradation effect verification: Repeat steps (3) to (5), first adjust the temperature of the catalytic reaction unit 5 to 330℃ and keep it stable, while keeping the other conditions unchanged. The detection module shows that the toluene degradation rate is ≥97% and the outlet concentration is ≤15PPM.

[0034] Example 3

[0035] (1) Waste gas mixing and adjustment: The toluene waste gas to be treated is introduced into the gas path control and mixing unit 4 of the device and mixed with the co-reaction gas, such as dry air. The mixing ratio is adjusted by the flow meter 16 and the regulating valve 17 to control the inlet flow rate of toluene waste gas to 900L / h and the inlet flow rate of air to 3600L / h, and the total gas flow rate is maintained at 4500L / h, so that the toluene concentration in the mixed waste gas is stabilized at 500PPM. (2) Gas space velocity setting: The gas space velocity of the mixed waste gas in the device is set to 30000 L / kg / h by the coordinated control of the flow meter 16 and the regulating valve 17, combined with the filling amount of 150 ml of Mn:Cu=9.5:1 manganese copper-based catalyst in the catalytic reaction unit 5, in order to meet the reaction requirements of the catalytic reaction unit 5. (3) Temperature control of catalytic unit: The circuit and temperature control unit 6 of the device are turned on. The temperature in the catalytic reaction unit 5 is detected in real time by the temperature sensing element 28. The temperature controller 29, combined with the timing control element 31, controls the on and off of the electromagnetic control switch 32, drives the heating element 30 to gradually raise the temperature of the catalytic reaction unit 5 from room temperature to 260°C, and maintains the reaction temperature at 260°C. (4) Catalytic degradation of toluene: The mixed waste gas with the space velocity set in step (2) is introduced into the catalytic reaction unit 5 so that the mixed waste gas can fully contact the catalyst filling layer 21 in the unit to carry out a catalytic reaction and achieve toluene degradation. (5) Exhaust gas analysis and exhaust: The degraded exhaust gas enters the exhaust pipe unit 8, and the toluene degradation rate is monitored in real time by the detection module in the unit. The monitoring results show that the catalytic toluene degradation rate is ≥78% at 260℃ and the outlet concentration is ≤110PPM. (6) Temperature adjustment and degradation effect verification: Repeat steps (3) to (5), adjust the temperature of the catalytic reaction unit 5 to 320℃ and maintain it, while keeping the other conditions unchanged. The detection module shows that the toluene degradation rate is ≥95% and the outlet concentration is ≤25PPM.

[0036] Example 4

[0037] (1) Waste gas mixing and adjustment: The toluene waste gas to be treated is introduced into the gas path control and mixing unit 4 of the device and mixed with the co-reaction gas, such as dry air. The mixing ratio is adjusted by the flow meter 16 and the regulating valve 17 to control the inlet flow rate of toluene waste gas to 900L / h and the inlet flow rate of air to 3600L / h, and the total gas flow rate is maintained at 4500L / h, so that the toluene concentration in the mixed waste gas is stabilized at 500PPM. (2) Gas space velocity setting: The gas space velocity of the mixed waste gas in the device is set to 30000 L / kg / h by the coordinated control of the flow meter 16 and the regulating valve 17, combined with the filling amount of 150 ml of Mn:Cu=8.5:1 manganese copper-based catalyst in the catalytic reaction unit 5, in order to meet the reaction requirements of the catalytic reaction unit 5. (3) Temperature control of catalytic unit: The circuit and temperature control unit 6 of the device are turned on. The temperature of the catalytic reaction unit 5 is detected in real time by the temperature sensing element 28. The temperature controller 29, combined with the timing control element 31, controls the on and off of the electromagnetic control switch 32, and drives the heating element 30 to gradually raise the temperature of the catalytic reaction unit 5 from room temperature to 270°C and maintain it at the reaction temperature of 270°C. (4) Catalytic degradation of toluene: The mixed waste gas with the space velocity set in step (2) is introduced into the catalytic reaction unit 5 so that the mixed waste gas can fully contact the catalyst filling layer 21 in the unit to carry out a catalytic reaction and achieve toluene degradation. (5) Exhaust gas analysis and venting: The degraded exhaust gas enters the exhaust pipeline unit 8. The toluene degradation rate is monitored in real time by the detection module in the unit. The monitoring results show that when the reaction is at 270℃, the toluene degradation rate is ≥82%, the outlet concentration is ≤90PPM, and there is no significant decay after 48 hours of continuous operation. The exhaust gas is directly vented through the venting main pipe 25. (6) Temperature adjustment and degradation effect verification: Repeat steps (3) to (5), adjust the temperature of the catalytic reaction unit 5 to 330℃ and keep it, while keeping the other conditions unchanged. The detection module shows that the toluene degradation rate is ≥96% and the outlet concentration is ≤20PPM. Stable operation was observed.

[0038] Example 5

[0039] (1) Waste gas mixing and adjustment: The toluene waste gas to be treated is introduced into the gas path control and mixing unit 4 of the device and mixed with the co-reaction gas, such as dry air. The mixing ratio is adjusted by the flow meter 16 and the regulating valve 17 to control the inlet flow rate of toluene waste gas to 450L / h and the inlet flow rate of air to 1800L / h, and the total gas flow rate is maintained at 2250L / h. The toluene concentration in the mixed waste gas is stabilized at 1000PPM. (2) Gas space velocity setting: The gas space velocity of the mixed waste gas in the device is set to 30000 L / kg / h by the coordinated control of the flow meter 16 and the regulating valve 17, combined with the 75 ml of Pt / Al2O3 precious metal catalyst filling amount in the catalytic reaction unit 5, to ensure that the airflow and the catalyst are in full contact. (3) Temperature control of the catalytic unit: The circuit and temperature control unit 6 of the device are turned on, and the temperature inside the catalytic reaction unit 5 is detected in real time by the temperature sensing element 28. The temperature controller 29, combined with the timing control element 31, controls the on and off of the electromagnetic control switch 32, and drives the heating element 30 to gradually raise the temperature of the catalytic reaction unit 5 from room temperature to 270°C or 320°C at a heating rate of 5°C / min, and maintains the reaction temperature at 270°C or 320°C. (4) Catalytic degradation of toluene: The mixed waste gas with the space velocity set in step (2) is introduced into the catalytic reaction unit 5 so that the mixed waste gas is in full contact with the catalyst filling layer 21 in the unit and a catalytic degradation reaction occurs at 310℃ to achieve full degradation of toluene. (5) Exhaust gas analysis and venting: The degraded exhaust gas enters the exhaust pipe unit 8, and the toluene degradation rate is monitored in real time by the detection module in the unit. The monitoring results show that at a reaction temperature of 320℃, the inlet concentration is 1000PPM, the toluene degradation rate during the catalytic degradation reaction is 98.5%, and the outlet concentration is 15PPM; at a reaction temperature of 270℃, the toluene catalytic degradation rate is ≥85%, the inlet concentration is 1000PPM, and the outlet concentration is ≤150PPM; the exhaust gas is vented through the venting main pipe 25. (6) Cost analysis: Although the noble metal-based Pt / Al2O3 catalyst has high degradation efficiency, it has the problems of high price and high cost. According to cost accounting, the cost and price of Pt / Al2O3 catalyst are significantly higher than those of manganese-copper-based catalyst. In terms of comprehensive operating cost analysis, including regeneration energy consumption and catalyst cost, the noble metal platinum-based catalyst is significantly higher than that of manganese-copper-based catalyst.

[0040] (ii) Traditional Regenerative Thermal Oxidation (RTO) Unit Comparison Example 1: Traditional RTO units use concrete foundations and are immovable. The main body includes dual regenerator chambers, a combustion chamber, an induced draft fan, and a chimney. The core components are a natural gas burner, a ceramic regenerator, and a PLC control system with temperature sensors. During operation, toluene waste gas is directly introduced into the RTO unit. Because the RTO requires a high concentration of VOCs to maintain combustion, the actual toluene concentration needs to be increased to over 5000 PPM, hence the additional toluene concentration unit. The temperature inside the combustion chamber is maintained at 850-900℃ by the natural gas burner, and the regenerator chamber switching cycle is 300 seconds to achieve heat recovery. Continuous operation results show that the toluene concentration in the exhaust gas is 120-180 PPM, with an initial concentration of 5000 PPM and an average toluene degradation rate of 97.0%. However, it relies on high-concentration intake gas. In terms of energy consumption, natural gas is consumed during the heating phase, and natural gas and induced draft fan energy are consumed during the stable operation phase. The operating cost is calculated based on natural gas, electricity, and the cost of replacing the ceramic heat storage body, resulting in a high total operating cost. In terms of safety, the local temperature of the combustion chamber exceeded 950℃ twice during operation, requiring the intake gas to be shut down for cooling. There was also a blockage of the heat storage body once, which caused a sudden increase in pressure and required shutdown for cleaning. There is also a risk of incomplete combustion producing CO, with a CO concentration of 50-80 PPM detected in the exhaust gas. In terms of spatial adaptability, the total area of ​​the device is 15㎡, and it needs to be fixedly installed outdoors or in a large workshop. It cannot be moved, and a safety distance of more than 3m must be reserved.

[0041] (III) Traditional Adsorption Method Device Comparative Example 2: The traditional adsorption device consists of a fixed carbon steel cabinet containing two adsorption towers, a desorption fan, and an electrically heated desorption unit. The core components are granular activated carbon and a solenoid valve assembly controlling the adsorption / desorption switching. During operation, toluene waste gas is directly introduced into the adsorption tower without dilution. After 4 hours of adsorption, the system switches to the other tower for adsorption, and desorption occurs in the saturated tower at a temperature of 120°C for 2 hours. Continuous long-term operation results show that the toluene degradation rate is 90%–92% in the initial adsorption stage (0–2h) and drops to 70%–75% in the later adsorption stage (2–4h). The average toluene degradation rate during operation is 81.5%. The degradation rate fluctuates greatly due to the partial saturation or failure of activated carbon adsorption. In terms of energy consumption, only the desorption fan needs to be on standby during the adsorption stage, while the energy consumption during the desorption stage is relatively large. The energy consumption of heating + fan is calculated based on electricity costs. Activated carbon needs to be replaced every 30 days, which is costly. In terms of safety, the desorption stage is prone to spontaneous combustion of activated carbon, requiring strict standardized operation. The generated desorption concentrated waste gas requires secondary treatment. If an RTO combustion device is used, additional costs will be incurred. In terms of space adaptability, the device occupies an area of ​​3–5 square meters, requires fixed installation, and space must be reserved for desorption waste gas treatment.

[0042] From the comparison of the evaluation indicators of the comparative examples and the embodiments, the device of this utility model has several advantages: 1) In terms of device size, the traditional RTO is 15㎡ and fixed installation, and the traditional adsorption method is 3-5㎡ and fixed installation; the skid-mounted integrated device of this utility model has a volume of about 1m³, and the skid-mounted type can be moved flexibly. 2) In terms of total energy consumption, the traditional regenerative thermal combustion RTO device has a reaction temperature of 800-950°C and high energy consumption; the traditional adsorption method has moderate energy consumption, but is prone to saturation and secondary pollution; for the same processing capacity, compared with the field cases of the above two methods, the total energy consumption of the skid-mounted device for catalytic degradation of toluene (CTO) of this utility model is significantly reduced, and the overall advantages are great. 3) Regarding the degradation rate of toluene waste gas, although the traditional RTO reaches 97.0%, it relies on high-concentration concentrated intake gas. The traditional adsorption method has an average degradation rate of only 81.5% and fluctuates greatly, and requires frequent regeneration or replacement. The toluene degradation rate of this utility model's catalytic oxidation (catalytic combustion, CTO) is 95%-99%, and it is stable. 4) In terms of safety, compared with traditional RTOs which have the risk of high temperature and the generation of toxic CO byproducts, and traditional adsorption methods which have the risk of desorption and spontaneous combustion and require secondary treatment; this utility model can completely degrade toluene at only 280-350°C through the efficient action of the catalyst, and provides a temperature-linked bypass design, with no safety hazards. 5) In terms of adaptability to applicable scenarios, compared with traditional RTOs which are suitable for centralized scenarios with large air volumes and traditional adsorption methods which are suitable for temporary scenarios with limited budgets, this utility model is suitable for small and scattered application scenarios with high demand, such as spray painting workshops, printing and dyeing workshops and small industrial emission sources.

[0043] In summary, this invention addresses the technical shortcomings of traditional regenerative thermal oxidizers (RTO) devices through a structural design that features precise gas path control, integrated core catalytic reaction units, and a flexible exhaust system. This results in a skid-mounted catalytic degradation device for toluene, offering advantages such as high efficiency, flexibility, low energy consumption, and high safety. Furthermore, in actual operation, it achieves a synergistic improvement in structural compactness, purification stability, energy economy, and operational reliability. Specifically, this skid-mounted catalytic degradation device for toluene not only boasts significant advantages such as small footprint and flexible mobility, adapting to the needs of decentralized catalytic degradation of toluene across multiple industries, but also has significantly lower operating costs than traditional RTOs and adsorption methods, demonstrating clear comprehensive advantages and high safety. Therefore, this invention is particularly suitable for decentralized scenarios such as painting workshops, dyeing workshops, and small industrial emission sources. Compared to regenerative thermal oxidizers for toluene treatment, this skid-mounted purification device and its application offer advantages such as high purification efficiency, low energy consumption, no secondary pollution, high safety, and ease of flexible movement and use across multiple scenarios.

[0044] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of this utility model. Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations of this utility model fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A skid-mounted gas purification device for the catalytic degradation of toluene, characterized in that: It includes a skid-mounted base (1), a cover (2) covering the skid-mounted base (1), and a functional unit integrated into the skid-mounted base (1) and located within the cover (2), the functional unit including: Gas path control and mixing unit (4) is used to regulate and mix toluene waste gas and co-reaction gas; The catalytic reaction unit (5) is connected to the gas path control and mixing unit (4) and is filled with CTO catalyst for catalytic degradation of toluene at 245-350°C. A circuit and temperature control unit (6) is used to power the device and control the reaction temperature of the catalytic reaction unit (5); A bypass pipeline unit (7) is connected in parallel between the inlet and outlet of the catalytic reaction unit (5) to guide gas in abnormal conditions; The exhaust pipe unit (8) is connected to the catalytic reaction unit (5) and is used to discharge the exhaust gas after the reaction. This device is suitable for the treatment of small-scale toluene waste gas emissions. The toluene concentration in the treated waste gas can be adjusted to 300-3000 PPM, and the gas space velocity is 3000-150000 L / kg / h. When the reaction temperature is 270-280℃, the toluene catalytic degradation rate is ≥90%; when the catalytic reaction temperature is 290-330℃, the toluene degradation rate is ≥95%.

2. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 1, characterized in that: The skid-mounted base (1) is made of lightweight aluminum alloy, stainless steel, or carbon steel with anti-rust coating. It has multiple lockable casters at the bottom. The cover (2) is a detachable aluminum alloy cover. The top and left side of the cover (2) are provided with ventilation and heat dissipation holes. The rear back is provided with an inspection opening and a sealing cover plate that matches the inspection opening.

3. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 1, characterized in that: The gas path control and mixing unit (4) includes a toluene waste gas inlet pipe (14), a co-reaction gas inlet pipe (15), a flow meter (16) and a regulating valve (17) respectively installed on the toluene waste gas inlet pipe (14) and the co-reaction gas inlet pipe (15), and a gas mixing pipe (18) located downstream of the two inlet pipes, which is used to ensure that the toluene waste gas and the co-reaction gas are fully mixed.

4. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 1, characterized in that: The catalytic reaction unit (5) includes a catalytic reaction tube (19), a heating element and a heat insulation layer (20) fitted outside the catalytic reaction tube (19), and a CTO catalyst filling layer (21) filled inside the catalytic reaction tube (19).

5. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 1, characterized in that: The bypass valve of the bypass pipeline unit (7) is an electromagnetic control valve (22), which is electrically connected to the circuit and temperature control unit (6). When the reaction temperature of the catalytic reaction unit (5) is abnormal, the circuit and temperature control unit (6) sends a control signal to the electromagnetic control valve (22) to automatically open the electromagnetic control valve (22) and realize gas bypass flow.

6. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 1, characterized in that: The exhaust pipe unit (8) includes an exhaust pipe body (23), a branch pipe (24), and a vent pipe (25); one end of the branch pipe (24) is connected to the exhaust pipe body (23), and the other end is provided with an exhaust gas sampling interface (26); the vent pipe (25) is connected to one end of the outlet of the catalytic reaction unit (5) through the exhaust pipe body (23), exhaust gas sampling is achieved through the branch pipe (24), and exhaust gas from the catalytic reaction is vented through the vent pipe (25).

7. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 1, characterized in that: The circuit and temperature control unit (6) includes: a power module (27) for providing working power; a temperature sensing element (28) installed on the outer wall of the catalytic reaction tube (19), with its detection end corresponding to the middle area of ​​the catalyst filling layer (21) for detecting temperature; a temperature controller (29) connected to the temperature sensing element (28) for receiving temperature signals and outputting control commands; and a heating element (30) located outside the catalytic reaction tube (19), whose on / off state is controlled by the output command of the temperature controller (29) to maintain the reaction temperature at 245-350°C. The circuit and temperature control unit (6) also includes a timing control element (31), which is used by the temperature controller (29) in conjunction with the timing control element (31) to control the on / off state of the electromagnetic control switch (32).

8. The skid-mounted gas purification device for catalytic degradation of toluene according to claim 4, characterized in that: The catalytic material of the CTO catalyst filling layer (21) is any one of the following: alumina-supported platinum-based CTO catalyst, promoter-supported silver-based CTO catalyst, or non-precious metal-based CTO catalyst composed of transition metal oxides.

Images