Optimized structure and operation method of high-boiling-point VOCS adsorption fixed bed

Abstract

The invention discloses an optimized structure of a high-boiling-point VOCs (volatile organic compounds) adsorption fixed bed and an operation method of the high-boiling-point VOCs adsorption fixed bed. The high-boiling-point VOCs adsorption fixed bed is formed by three gradient composite adsorbent layers (a pretreatment layer, a main adsorption layer and a deep adsorption layer), a multi-dimensional airflow distribution device (a guide plate group, a porous splitter plate and a conical guide groove) and an intelligent regeneration control unit (hot nitrogen circulation, vacuum desorption and machine learning). The problems that a traditional fixed bed is low in adsorption capacity, short in penetration time, high in regeneration energy consumption and short in service life are solved. The adsorption capacity of the device to high-boiling-point VOCs (such as naphthalene and anthraquinone) reaches 25%-30%, the penetration time is prolonged to 180-240 minutes, the regeneration energy consumption is smaller than or equal to 120 kWh / period, the service life of an adsorbent is prolonged to 18-24 months, and the device is suitable for deep treatment of high-boiling-point VOCs waste gas in the industries of petrochemical engineering, printing and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of volatile organic compounds (VOCs) pollution treatment, in particular to an optimized structure of a high-boiling-point VOCs adsorption fixed bed and an operation method thereof. BACKGROUND

[0002] High-boiling-point VOCs exist widely in waste gas of petrochemical refining, coal chemical industry, printing and coating, pharmaceutical and electronic chemical manufacturing industries, etc. The high-boiling-point VOCs have a large molecular diameter (≥0.6 nm), strong polarity, high adsorption heat (≥40 kJ / mol), and are prone to chemical adsorption or polymerization reaction with adsorbents, which causes problems such as low adsorption efficiency (adsorption capacity <10%) of traditional fixed-bed adsorption materials (such as ordinary activated carbon, molecular sieve), short breakthrough time (<60 minutes), high regeneration energy consumption (≥200 kWh / cycle), large pressure drop (>2000 Pa) and short service life (<6 months) of the high-boiling-point VOCs, which seriously restricts the efficient treatment of high-boiling-point VOCs waste gas.

[0003] Specifically, the prior art has the following problems:

[0004] 1. Insufficient adsorption selectivity: the pore size distribution of a single adsorbent (such as activated carbon) does not match the size of high-boiling-point VOCs molecules, and large molecules of VOCs are prone to penetrate the bed, resulting in a decrease in purification efficiency;

[0005] 2. Large bed pressure drop: high-boiling-point VOCs molecules have large diffusion resistance, and the airflow in the fixed bed is unevenly distributed (such as excessively high flow rate in the corner area), which intensifies the pressure drop due to local vortex flow;

[0006] 3. High regeneration energy consumption: traditional hot air regeneration requires high temperature (≥200℃) and long time blowing (≥4 hours), and the mixture of air and VOCs is prone to cause combustion and explosion risk, and the energy consumption accounts for more than 40% of the operating cost;

[0007] 4. Short service life of adsorbent: high-boiling-point VOCs are prone to irreversible adsorption (such as π-π stacking of naphthalene on the surface of activated carbon) with active sites on the surface of adsorbents, or catalytic decomposition to produce carbon deposition, which causes rapid deactivation of the adsorbent;

[0008] 5. Low degree of intelligentization: the traditional device relies on manual experience to set the adsorption-desorption cycle, and cannot dynamically adjust according to real-time working conditions (such as VOCs concentration fluctuation and humidity change), which is prone to cause energy waste or breakthrough risk.

[0009] Therefore, it is urgent to develop a high-boiling-point VOCs adsorption fixed bed with optimized structure, efficient adsorption, energy-saving regeneration, long service life and intelligence. SUMMARY

[0010] In view of the deficiencies of the prior art, the present application provides an optimized structure and operation method of a high-boiling-point VOCs adsorption fixed bed, which realizes efficient adsorption (adsorption capacity >= 25%) of high-boiling-point VOCs, long breakthrough time (>= 180 minutes), low regeneration energy consumption (<= 120 kWh / period), low pressure drop (<= 1200 Pa) and long service life (>= 18 months) through gradient design of a composite adsorbent layer, multi-dimensional airflow distribution optimization, intelligent regeneration control and long service life guarantee technology, and is suitable for deep treatment of high-boiling-point VOCs waste gas in petrochemical, printing and other industries.

[0011] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0012] An optimized structure of a high-boiling-point VOCs adsorption fixed bed, comprising a bed body shell, a composite adsorbent layer, an airflow distribution device, a regeneration unit and an intelligent control system;

[0013] I. Composite adsorbent layer: a three-layer gradient composite structure is adopted, and the pretreatment layer, the main adsorption layer and the deep adsorption layer are sequentially arranged from the gas inlet end to the gas outlet end, and the material, thickness and particle size parameters of each layer are as follows:

[0014] 1. Pretreatment layer (first layer): thickness 150-250 mm, filled with granular amino-modified activated carbon (iodine value >= 900 mg / g, specific surface area >= 1200 m 2 / g, amino grafting rate 6%-10%) with a particle size of 2-5 mm, used for adsorbing small molecule interferents (such as water vapor, methanol, ethanol) and adjusting the bed humidity (outlet humidity <= 50% RH);

[0015] 2. Main adsorption layer (second layer): thickness 400-600 mm, filled with strip-shaped modified ZSM-5 molecular sieve (silicon aluminum ratio 4-6, pore size 0.8-1.2 nm) with a particle size of 1-3 mm, and 20%-25% metal organic framework (MOFs, such as ZIF-8 or MIL-101) is loaded on the surface, so as to enhance the chemical adsorption stability of high-boiling-point VOCs through the micropore confinement effect of MOFs;

[0016] 3. Deep adsorption layer (third layer): thickness 200-300 mm, filled with porous cross-linked polystyrene resin (specific surface area >= 800 m 2 / g, pore volume >= 1.2 cm 3 / g) with a particle size of 0.5-1 mm, used for capturing escaped low-concentration high-boiling-point VOCs (outlet concentration <= 5 mg / m 3 ).

[0017] II. Airflow distribution device: arranged at the top of the bed body, comprising a set of flow guide plates, a multi-hole distribution plate and a conical flow guide groove, and the specific structure is as follows:

[0018] 1. Deflector set: composed of 4-6 arc-shaped plates (inclination angle 35°-50°, opening rate 45%-55%) evenly distributed along the cross section of the bed body, which evenly disperses the incoming gas to the cross-sectional area of the bed body and eliminates the "jet flow" phenomenon at the gas inlet end;

[0019] 2. Multi-hole distribution plate: located at the bottom of the composite adsorbent layer, with an opening rate of 65%-75% and a hole diameter of 8-12 mm, and uniformly distributed conical protrusions (height 5-10 mm) on the plate surface, cooperating with the conical flow guide groove (inclination angle 70°-80°) at the bottom of the bed body to guide the airflow to flow uniformly along the axial direction of the bed layer and eliminate the airflow dead zone at the bottom;

[0020] 3. Three to five vertical flow guide holes (diameter 10-15 mm, spacing 200-300 mm) are provided on the side wall of the bed body to balance the radial pressure difference of the bed layer and ensure uniformity of airflow distribution (deviation ≤±5%).

[0021] Three, Regeneration unit: integrated into the side of the bed body, including a hot nitrogen gas circulation pipeline, a vacuum desorption module, and a temperature-pressure linkage control system, with the following specific structure:

[0022] 1. Hot nitrogen gas circulation pipeline: connected to the top (gas inlet) and bottom (gas outlet) of the bed body, with a built-in spiral coil electric heater (heating power 10-20 kW, heating range 300-450℃), a gas flow meter (accuracy ±0.5%), and a high-temperature resistant stop valve (temperature resistance ≥400℃);

[0023] 2. Vacuum desorption module: including a rotary vane vacuum pump (suction speed 150-250 L / s), a condenser (condensation temperature -30℃, heat exchange area 5-8 m 2 ), and an oil-water separator (separation accuracy ≤1 μm) for low-energy deep desorption;

[0024] 3. Temperature-pressure linkage control system: composed of thermocouples (accuracy ±1℃, spacing 100-200 mm) and pressure sensors (accuracy ±0.1 kPa, spacing 150-250 mm) inside the bed layer, which real-time feedback temperature (T) and pressure drop (ΔP) data to the PLC controller.

[0025] Four, Intelligent control system: based on an industrial-grade PLC controller, integrating adsorption-desorption cycle optimization module, regeneration parameter self-learning module, and fault warning module, with the following specific functions:

[0026] 1. Adsorption-desorption cycle optimization module: Based on the inlet VOCs concentration (C_in), humidity (RH), and bed residual adsorption capacity (Q_residual), the optimal adsorption time (t_opt) is dynamically calculated, the formula is: t_opt = (Q_total x η) / (C_in x Q_in), where Q_total is the total adsorption capacity of the adsorbent, η is the safety factor (0.8-0.9), Q_in is the exhaust gas flow;

[0027] 2. Regeneration parameter self-learning module: Through machine learning algorithm (such as random forest) analysis of historical cycle data (C_in, RH, T, ΔP, regeneration energy consumption), optimization of heat nitrogen temperature (T_heat), flow (Q_heat) and vacuum desorption time (t_vacuum);

[0028] 3. Fault warning module: Set threshold (such as ΔP > 1200 Pa, T > 450℃, C_out sudden increase of 20%), trigger sound and light alarm and automatically switch to safety mode (such as reduce exhaust gas flow, pause adsorption).

[0029] An optimized structure and operation method of a high-boiling-point VOCs adsorption fixed bed, the operation method includes an adsorption stage, a desorption stage, and an intelligent control process, the specific steps are as follows:

[0030] S1, adsorption stage:

[0031] 1. Exhaust gas pretreatment: After the exhaust gas is treated by cyclone dust removal (efficiency ≥ 99%) and condensation demisting (dew point temperature ≤ 10℃), the humidity is reduced to below 60% RH, and the bed body top is entered;

[0032] 2. Uniform air distribution: The exhaust gas passes through the guide plate group and the multi-hole distribution plate, and the flow rate is controlled at 0.15-0.25 m / s (empty bed flow rate), and is uniformly entered into the pretreatment layer;

[0033] 3. Graded adsorption: Pretreatment layer: adsorb water vapor (removal rate ≥ 80%), methanol (removal rate ≥ 90%) and ethanol (removal rate ≥ 95%), outlet humidity ≤ 50% RH; Main adsorption layer: high-boiling-point VOCs (such as naphthalene, anthraquinone) are chemically adsorbed by MOFs micropore confinement effect, adsorption capacity ≥ 25% (by mass); Deep adsorption layer: capture escaped low-concentration VOCs (such as naphthalene with a concentration <100 mg / m 3 ); 3 ;

[0034] 4. Dynamic termination of adsorption: When the intelligent control system calculates t_opt (such as 150 minutes) or the bed pressure drop ΔP > 1200 Pa (real-time monitoring), the inlet valve is automatically closed, and the desorption stage is started.

[0035] S2, desorption stage:

[0036] 1. Primary hot nitrogen regeneration: Turn on the hot nitrogen circulation pipeline and pass in 350-400°C hot nitrogen (flow rate is 1.2-1.5 times that of the adsorption stage), reverse blowing from the bottom of the bed body, lasting for 45-60 minutes, to remove physically adsorbed VOCs (desorption rate ≥ 90%);

[0037] 2. Deep vacuum desorption: Switch to the vacuum desorption module, and vacuum pump to -30 kPa while passing in 200-250°C hot nitrogen (pulse injection, once every 3 minutes, 15 seconds each time), to desorb residual high-boiling VOCs (such as phenanthrene, phthalate ester), desorption rate ≥ 95%;

[0038] 3. Cooling: Turn off the hot nitrogen and pass in normal temperature nitrogen (flow rate is 1 times that of the adsorption stage) to replace the bed, and wait until the temperature drops to below 40°C before standby.

[0039] S3. Intelligent control process:

[0040] 1. Data acquisition: Real-time acquisition of inlet VOCs concentration (PID online monitor), humidity (capacitive humidity sensor), bed temperature (K-type thermocouple), pressure drop (diffused silicon pressure sensor), and regeneration energy consumption (electricity meter);

[0041] 2. Cycle optimization: Machine learning model trained based on historical data, to predict the optimal adsorption time (t_opt) of the next cycle, error ≤ ±5 minutes;

[0042] 3. Parameter self-adjustment: According to real-time T and ΔP data, dynamically adjust the hot nitrogen temperature (such as T < 350°C, increase heating power) and flow rate (such as ΔP > 1000 Pa, increase flow rate by 10%);

[0043] 4. Fault handling: When ΔP > 1200 Pa or T > 450°C, trigger the safety interlock, turn off the heater, stop the waste gas inlet, and start emergency nitrogen purging (flow rate is 1.5 times normal), until the fault is eliminated.

[0044] Advantages

[0045] Compared with the prior art, the advantages of the present application are:

[0046] 1. Adsorption capacity is significantly improved: The adsorption capacity of three-layer gradient composite adsorbent for high-boiling VOCs (such as naphthalene) is 25%-30% (mass ratio), which is 3-4 times higher than that of single activated carbon;

[0047] 2. Breakthrough time is greatly extended: Through airflow distribution optimization and pretreatment layer humidity control, the breakthrough time is extended from 30-60 minutes of the traditional method to 180-240 minutes;

[0048] 3. Significant reduction in energy consumption: The combination of hot nitrogen circulation and vacuum desorption process, the energy consumption of regeneration is less than or equal to 120 kWh / cycle, which is reduced by more than 50% compared with traditional hot air regeneration;

[0049] 4. Significant reduction in pressure drop: The combination of porous shunt plate and flow guide plate group makes the bed pressure drop less than or equal to 1200 Pa (0.25 m / s of empty bed flow rate), which is reduced by 40%-50% compared with traditional fixed bed;

[0050] 5. Prolonged service life of adsorbent: The modified adsorbent has strong resistance to poisoning (naphthalene residual amount <2%), and the replacement cycle is extended to 18-24 months;

[0051] 6. High degree of intelligence: Cycle optimization and parameter self-adjustment based on machine learning, dynamic energy-saving operation, and more than 20% improvement in energy utilization. BRIEF DESCRIPTION OF DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0053] Figure 1 Stereoscopic structure of the optimized structure of the high-boiling-point VOCs adsorption fixed bed Figure One ;

[0054] Figure 2 Stereoscopic structure of the optimized structure of the high-boiling-point VOCs adsorption fixed bed Figure Two ;

[0055] Figure 3 Internal structure diagram of the optimized structure of the high-boiling-point VOCs adsorption fixed bed

[0056] Figure 4 Partial structure diagram of the composite adsorbent layer and the gas flow distribution device

[0057] Markings in the figure: 1-bed body shell; 2-composite adsorbent layer; 21-preprocessing layer; 22-main adsorption layer; 23-depth adsorption layer; 3-gas flow distribution device; 31-flow guide plate group; 32-porous shunt plate; 33-conical flow guide groove; 4-regeneration unit; 41-hot nitrogen circulation pipeline; 42-vacuum desorption module; 5-intelligent control system; 6-waste gas inlet; 7-purified gas outlet; 8-regeneration gas inlet; 9-regeneration gas outlet. DETAILED DESCRIPTION

[0058] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0059] Example 1: Application of the present application in treating high-boiling VOCs in a petrochemical refinery

[0060] In the waste gas of a 2 million tons / year catalytic cracking unit of a petrochemical enterprise, the main pollutants are naphthalene (concentration 800 mg / m 3 ), anthraquinone (concentration 200 mg / m 3 ) and a small amount of phthalate (concentration 50 mg / m 3 ), with an initial humidity of 75% RH, and the air volume to be treated is 30000 m 3 / h. The present application is used for treatment, and the specific implementation steps are as follows:

[0061] 1. Device deployment and parameter setting

[0062] The size of the bed body shell 1 is: 8 m long x 2.5 m wide x 4 m high (effective volume 80 m 3 );

[0063] The composite adsorbent layer 2 is: a pretreatment layer 21 (200 mm thick, particle size 3-5 mm of amino-modified activated carbon), a main adsorption layer 22 (500 mm thick, particle size 1-3 mm of modified ZSM-5 molecular sieve loaded with 22% ZIF-8), and a deep adsorption layer 23 (250 mm thick, particle size 0.5-1 mm of crosslinked polystyrene resin);

[0064] The gas flow distribution device 3 is: a set of flow guide plates 31 (5 arc-shaped plates, opening rate 50%), a multi-hole flow distribution plate 32 (opening rate 70%, hole diameter 10 mm), and a conical flow guide groove 33 (inclination angle 75°);

[0065] The regeneration unit 4 is: a hot nitrogen gas circulation pipeline 41 (spiral coil electric heater power 15 kW), and a vacuum desorption module 42 (rotary vane vacuum pump 200 L / s, condenser -30℃);

[0066] The intelligent control system 5 is: a PLC controller (Siemens S7-1200), an integrated PID online monitor (precision ±2%), a capacitive humidity sensor (precision ±3% RH), a K-type thermocouple (precision ±1℃), and a diffused silicon pressure sensor (precision ±0.1 kPa).

[0067] 2. Adsorption stage operation

[0068] The exhaust gas enters the top of the bed body after cyclone dust removal (efficiency 99.5%) and condensation demisting (dew point temperature 8℃), and the empty bed flow rate is 0.2 m / s;

[0069] The PID online monitor shows that the inlet naphthalene concentration is 780 mg / m 3 , anthracene 195 mg / m 3 , phthalate 48 mg / m 3 , and the humidity is 73% RH;

[0070] After adsorption by the pretreatment layer 21, the humidity is reduced to 48% RH, and the removal rates of methanol (none) and ethanol (none) meet the standards;

[0071] During the adsorption process of the main adsorption layer 22, ZIF-8 microporous confinement effect captures naphthalene molecules (adsorption capacity 28%), and anthracene is adsorbed by the molecular sieve polar site;

[0072] The deep adsorption layer 23 captures low-concentration naphthalene (concentration <50 mg / m 3 ) that escapes, and the outlet concentration is stable at ≤4 mg / m 3 ;

[0073] After 165 minutes of operation, the intelligent control system 5 calculates t_opt = 160 minutes (theoretical value) and triggers the desorption program.

[0074] 3. Desorption stage operation

[0075] Primary hot nitrogen regeneration: 380℃ hot nitrogen (flow rate 18000 m 3 / h) is introduced, and reverse sweeping is performed for 50 minutes, the bed layer temperature is raised to 390℃, and the naphthalene desorption rate is 92%;

[0076] Deep vacuum desorption: switch to a vacuum pump (pumping speed 200 L / s), vacuum degree -30 kPa, 220℃ hot nitrogen pulse injection (once every 3 minutes, 15 seconds each time), for 25 minutes, naphthalene desorption rate 96% (total desorption rate 98%);

[0077] Cooling: normal temperature nitrogen (flow rate 15000 m 3 / h) is introduced for 30 minutes, the bed layer temperature is reduced to 38℃, and it is ready for use.

[0078] 4. Operation effect verification

[0079] Purification efficiency: the outlet naphthalene concentration is stable at <2 mg / m 3 (removal rate >99.75%), anthracene <0.5 mg / m 3 (removal rate >99.7%), and phthalate <0.2 mg / m 3 (removal rate >99.6%);

[0080] Penetration time: 172 min (design value 180 min) for 5 cycles of continuous operation;

[0081] Energy consumption for regeneration: 105 kWh per desorption (210 kWh for traditional hot air regeneration);

[0082] Service life of adsorbent: After 18 months of operation, the pretreatment layer 21 activated carbon amino grafting rate decreased by only 1.2%, the main adsorption layer 22 ZIF-8 load decreased by 3%, and the deep adsorption layer 23 resin pore volume decreased by 2%, still meeting the purification requirements.

[0083] Example 2: Application of the present application to the treatment of high-boiling VOCs in a printing workshop

[0084] A printing enterprise uses solvent-based ink (containing phenanthrene and sucralose), and the concentration of phenanthrene in the exhaust gas is 500 mg / m 3 , the concentration of sucralose is 150 mg / m 3 , the humidity is 80% RH, and the air volume is 20000 m 3 / h. The key parameters and effects after treatment with the device of the present application are as follows:

[0085] Composite adsorbent layer 2: pretreatment layer 21 (180 mm thick, particle size 2-4 mm amino-modified activated carbon), main adsorption layer 22 (450 mm thick, particle size 1-2 mm modified ZSM-5 molecular sieve loaded with 20% MIL-101), deep adsorption layer 23 (220 mm thick, particle size 0.6-0.8 mm crosslinked polystyrene resin);

[0086] Adsorption stage: empty bed flow rate 0.18 m / s, pretreatment layer 21 humidity reduced to 45% RH, main adsorption layer 22 phenanthrene adsorption capacity 26%, sucralose specifically adsorbed by MOFs due to strong polarity (adsorption capacity 30%);

[0087] Desorption stage: primary hot nitrogen temperature 360℃, flow rate 12000 m 3 / h, purging for 45 minutes; vacuum desorption vacuum degree -25 kPa, 200℃ hot nitrogen gas pulse injection, desorption time 20 minutes;

[0088] Operation effect: outlet phenanthrene concentration <1 mg / m 3 , sucralose <0.3 mg / m 3 , penetration time average 195 min, regeneration energy consumption 98 kWh / cycle, adsorbent service life 20 months.

[0089] The above is only a preferred embodiment of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An optimized structure of high-boiling-point VOCs adsorption fixed bed, comprising a bed body shell, a composite adsorbent layer, a gas flow distribution device, a regeneration unit and an intelligent control system; characterized in that the composite adsorbent layer is a three-layer gradient composite structure, and the pre-treatment layer, the main adsorption layer and the deep adsorption layer are sequentially arranged from the gas inlet end to the gas outlet end; the gas flow distribution device comprises a set of guide plates, a porous shunt plate and a conical guide groove; the regeneration unit integrates a hot nitrogen gas circulation pipeline and a vacuum desorption module; the intelligent control system is based on a PLC controller and integrates an adsorption-desorption cycle optimization module, a regeneration parameter self-learning module and a fault early warning module.

2. The optimized structure of high boiling point VOCs adsorption fixed bed according to claim 1, characterized in that, The pretreatment layer has a thickness of 150-250 mm and is filled with granular amino-modified activated carbon having a particle size of 2-5 mm, an iodine value of ≥900 mg / g, a specific surface area of ≥1200 m 2 / g, and an amino grafting rate of 6%-10%.

3. The optimized structure of high boiling point VOCs adsorbing fixed bed according to claim 1, characterized in that, The main adsorption layer has a thickness of 400-600 mm and is filled with strip-shaped modified ZSM-5 molecular sieves with a particle size of 1-3 mm, the modified ZSM-5 molecular sieves have a silicon-aluminum ratio of 4-6, a pore size of 0.8-1.2 nm and a surface load of 20%-25% of metal organic frameworks, and the metal organic frameworks are selected from ZIF-8 or MIL-101.

4. The optimized structure of high boiling point VOCs adsorbing fixed bed according to claim 1, characterized in that, The deep adsorption layer thickness is 200-300mm, and the porous crosslinked polystyrene resin with a particle size of 0.5-1mm is filled, the specific surface area of the crosslinked polystyrene resin is ≥800m 2 / g, and the pore volume is ≥1.2cm 3 / g.

5. The optimized structure of high boiling point VOCs adsorbing fixed bed according to claim 1, characterized in that, The set of guide plates is composed of 4-6 arc-shaped plates, the arc-shaped plates have an inclination angle of 35°-50° and an opening rate of 45%-55%; the porous shunt plate is located at the bottom of the composite adsorbent layer, has an opening rate of 65%-75%, a pore size of 8-12 mm and a plurality of conical protrusions uniformly distributed on the plate surface, and the conical protrusions have a height of 5-10 mm; and the conical guide groove has an inclination angle of 70°-80°.

6. The optimized structure of high boiling point VOCs adsorbing fixed bed according to claim 1, characterized in that: The hot nitrogen gas circulation pipeline comprises a spiral coil electric heater, a gas flow meter and a high-temperature-resistant stop valve; and the vacuum desorption module comprises a rotary vane vacuum pump, a condenser and an oil-water separator.

7. The optimized structure of high boiling point VOCs adsorbing fixed bed according to claim 1, characterized in that: The calculation formula of the adsorption-desorption cycle optimization module is t_opt=(Q_total×η) / (C_in×Q_in), wherein Q_total is the total adsorption capacity of the adsorbent, η is a safety factor (0.8-0.9), and C_in is the exhaust gas flow rate; the regeneration parameter self-learning module optimizes the temperature, flow rate and vacuum desorption time of the hot nitrogen gas based on a random forest algorithm; and the threshold values set in the fault early warning module include a pressure drop of >1200 Pa, a temperature of >450℃ and a sudden increase of 20% in the outlet concentration.

8. A method for operating a high-boiling VOCs adsorbing fixed bed based on the optimized structure according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1, adsorption stage: the exhaust gas enters the bed body after being pre-treated, is uniformly distributed by the gas flow distribution device, sequentially passes through the pre-treatment layer, the main adsorption layer and the deep adsorption layer, the empty bed flow rate is controlled to be 0.15-0.25 m / s, and the dynamic termination adsorption condition is t_opt or a bed layer pressure drop of >1200 Pa; S2, desorption stage: first, 350-400℃ hot nitrogen gas is introduced for reverse sweeping for 45-60 minutes, then the vacuum desorption is switched to for 20-25 minutes, and finally, normal-temperature nitrogen gas is introduced for cooling to below 40℃; S3, intelligent control: the inlet VOCs concentration, humidity, bed layer temperature and pressure drop are collected in real time, the adsorption time and regeneration parameters are dynamically adjusted, and the safety interlock is triggered when a fault occurs.

9. The method of claim 8, wherein the high boiling point VOCs adsorbed fixed bed is operated at a temperature of about 20°C to about 60°C. The pre-treatment target of the pre-treatment layer is that the water vapor removal rate is ≥80%, the methanol removal rate is ≥90%, the ethanol removal rate is ≥95%, and the outlet humidity is ≤50% RH.

10. The high boiling point VOCs adsorptive fixed bed operating method according to claim 8, characterized by: The high-boiling-point VOCs adsorption capacity of the main adsorption layer is ≥ 25%, and the outlet VOCs concentration of the deep adsorption layer is ≤ 5 mg / m 3 .

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