Adsorption and desorption device and treatment method for treating waste gas containing light hydrocarbon VOCs (Volatile Organic Compounds)

Abstract

The invention relates to the technical field of adsorption and desorption, and discloses an adsorption and desorption device for treating waste gas containing light hydrocarbon VOCs and a treatment method.The adsorption and desorption device comprises an inlet flame arrester, a light hydrocarbon VOCs waste gas inlet is fixed to one end of the inlet flame arrester, and a plurality of induced draft fans are fixed to the other end of the inlet flame arrester through Y-shaped pipelines; the induced draft fans are fixed with adsorption and desorption devices through pipelines, a plurality of functional layers are arranged in the adsorption and desorption devices, each functional layer comprises an adsorption and desorption layer, a heat preservation and cold insulation layer and a condensation heat exchange layer, and oil-water separators are fixed in the condensation heat exchange layers of the adsorption and desorption devices through pipelines. Through the unique structural design of the adsorption and desorption device, the pipeline arrangement is greatly simplified, the occupied area of the device is effectively reduced, the investment cost is reduced, the temperature control is ensured, and the potential safety hazard caused by high temperature is avoided, so that the problem of overhigh space and investment cost is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of adsorption and desorption, and in particular to an adsorption and desorption device and a treatment method for treating waste gas containing light hydrocarbons (VOCs). Background Art

[0002] At present, the key industries for the treatment of waste gas containing light hydrocarbon VOCs mainly include petroleum refining, petrochemicals and other petrochemical industries, organic chemicals, coal chemicals, coking and other chemical industries, as well as oil storage, transportation and loading and unloading. Treatment technologies are mainly divided into two categories: recovery and destruction. Recovery technology refers to the recycling of light hydrocarbon VOCs in waste gas by condensation, absorption, adsorption, membrane separation and other methods; destruction technology refers to the use of direct combustion, regenerative thermal combustion (RTO), regenerative catalytic combustion (RCO) and other methods to decompose the difficult-to-recover light hydrocarbon VOCs into water and carbon dioxide. In practical applications, in order to achieve the expected treatment effect, a combination of multiple technologies is generally used to achieve complementary synergy between different technologies to meet the emission requirements of waste gas containing light hydrocarbon VOCs. Recovery technology, especially the adsorption method that plays a key role in emission reduction in recovery, is more in line with the requirements of ecological green sustainable development. However, with the continuous deepening of domestic and foreign scholars' research on adsorption technology, the constraints have become more prominent.

[0003] For the current adsorption and desorption devices, on the one hand, due to the design of the device itself, organic components will gradually accumulate in the adsorbent, which not only gradually reduces the adsorption efficiency, but also has an adverse effect on the desorption efficiency, causing the adsorption and desorption effect of the entire device to be greatly reduced; on the other hand, although the device is dealing with pollution problems, it is also consuming a large amount of water, electricity and other resources, and in the process of continuously purifying water bodies and generating electricity, it is also continuously emitting carbon dioxide, etc., and cannot achieve true energy conservation and carbon reduction. Therefore, in order for the adsorption and desorption device to operate stably and efficiently for a long time, have high adsorption efficiency, and have a thorough desorption effect, and to achieve true energy conservation and carbon reduction, it is crucial to design an adsorption and desorption device and a treatment method for the treatment of light hydrocarbon VOCs waste gas that can meet the above conditions.

[0004] According to the publication number CN115671937A, a crude oil recovery device in oil and gas based on solar condensation adsorption is disclosed, which includes a condensing unit (the condensing unit contains an absorption refrigeration unit and a solar heat collection unit), an adsorption unit, an oil-water separator and an oil storage tank. The adsorption unit is connected to the condensing unit, and the condensing unit and the adsorption unit are also respectively connected to the oil-water separator, and the oil-water separator is connected to the oil storage tank. The high-temperature oil and gas are input into the condensing unit, the condensed liquid is input into the oil-water separator, and the uncondensed oil and gas are input into the adsorption unit. The adsorption unit adsorbs and condenses the oil and gas, and then inputs the oil-water separator. The oil-water separator inputs the separated crude oil into the oil storage tank to complete the crude oil recovery. The device has a high recovery rate, utilizes solar heating, and reduces the consumption of a certain amount of fossil resources, but the device still needs to be equipped with an electric auxiliary heater, and the structure is complex, the floor space is large, and the investment and operation costs are high.

[0005] According to the publication number CN106731466A, a recyclable VOCs waste gas adsorption vacuum desorption treatment system is disclosed, the treatment system includes at least one adsorption tower device, the adsorption tower device includes an adsorption tower, the adsorption tower liner is provided with an adsorbent, the top of the adsorption tower is provided with an exhaust pipe and an exhaust valve, the bottom of the adsorption tower is provided with an intake pipe and an intake valve connected to the exhaust pipe, the adsorption tower is provided with a jacket for heating the adsorption tower, the jacket and the adsorption tower liner are provided with a vent, and the exhaust pipe, intake pipe, and vent of the adsorption tower are extended out of the jacket; the exhaust pipe side is connected to a fan through a one-way valve and a switch valve, and the fan outlet is connected to the desorption tail gas treatment device. The device can realize the reuse of the adsorbent, the adsorbent desorption has low energy consumption, small desorption gas volume, high safety, high waste gas concentration, and adopts direct combustion or condensation to recover the solvent, so the treatment cost is low. However, the heat source used in this system is steam or hot oil. If the heat source is steam, in order to keep the system running stably during desorption, high-temperature steam needs to be continuously introduced, which will increase the overall energy consumption. If the heat source is hot oil, although the system can keep running stably during desorption for a long time, the hot oil cools down slowly, which will affect the subsequent adsorption efficiency, which is not worth the loss. Moreover, my country's control over the use of combustion to treat VOCs is becoming more and more stringent, and this method is no longer suitable for the current ecological environment development needs.

[0006] According to the publication number CN111821963A, a vacuum desorption method for organic waste gas adsorbent is disclosed, which includes a heating outer tank and a catalytic box, the left and right side walls of the heating outer tank are fixedly covered with a cover, the inner wall of the cover is fixedly connected with a heating plate, and the desorption tank is fixedly inserted vertically downward in the inner cavity of the heating outer tank; the inner wall of the desorption tank is horizontally fixed and connected with multiple equidistantly distributed heat pipes. This method uses a vacuum pump to blow the waste gas in the desorption tank through a suction pipe to the drive box through a blow pipe, and the blower impeller in the drive box is rotated at a high speed, thereby driving the stirring rod to fully stir the material in the inner cavity of the desorption tank. Although this can improve the desorption effect and efficiency, and does not require a motor drive, this method is only suitable for projects with large processing volume and low concentration, and is not applicable to projects with small and medium processing volumes. And this method is easy to damage the material in the inner cavity of the desorption tank, shorten the service life of the adsorbent, and indirectly increase the processing cost.

[0007] According to the publication number CN111298597A, a novel high-efficiency vacuum desorption system complete set and a waste gas treatment method are disclosed, which includes a vacuum desorption device, an RCO catalytic combustion device, a heat recovery desorption device and a PLC control box, characterized in that the air outlet end of the vacuum desorption device is connected to the RCO catalytic combustion device through a first pipeline, the air inlet end is provided with a heat recovery desorption device, the heat recovery desorption device is connected to the RCO catalytic combustion device through a second pipeline, the PLC control box is connected to the vacuum desorption device, the RCO catalytic combustion device and the heat recovery desorption device, etc., the vacuum desorption device includes a desorption kettle, and a jacket oil temperature heating device is provided at the bottom of the desorption kettle. Although this method can feed the exhaust gas after RCO combustion into the vacuum thermal desorption kettle through the heat recovery device, and the overall device will not have exhaust gas discharge, but the desorption temperature is higher than that of normal pressure. In order to maintain a constant temperature in the desorption kettle and thus maintain high-efficiency desorption, the hot oil needs to be continuously heated, which in turn increases the energy consumption of desorption. In addition, adsorption and desorption are processed ex situ, which also increases the number of equipment, the difficulty and complexity of control, and the floor space occupied.

[0008] According to the publication number CN218189694U, a vacuum desorption box for activated carbon that can recover heat energy is disclosed. The vacuum desorption box includes a box body, a placement plate is fixedly installed inside the box body, a heating box is fixedly installed at the bottom of the inner cavity of the box body, a steam outlet pipe is connected to the top of the box body, and a heat recovery mechanism is provided on the outer wall of the box body. The heat recovery mechanism is connected to the steam outlet pipe, and the bottom of the heat recovery mechanism is connected to a water inlet pipe, and the other end of the water inlet pipe is connected to the heating box. The vacuum desorption box preheats the aqueous solution entering the heating box through the heat recovery mechanism, increases the temperature of the aqueous solution, and shortens the boiling time of the aqueous solution inside the heating box, thereby achieving energy saving. After the discharged steam enters the heat recovery mechanism, it can accelerate the condensation of steam with gas molecules, which is convenient for recovering gas molecules. In addition, a pressure control mechanism is installed on the top of the box body. The pressure control mechanism can ensure that there is sufficient steam inside the box body during the activated carbon desorption process, so that the steam fully heats the activated carbon and avoids the steam being discharged directly through the steam outlet pipe. However, the equipment has a large system resistance and steam needs to be constantly replenished. In a cycle, this part of the steam also becomes waste gas containing VOCs, which increases the additional processing volume and is not very practical.

[0009] According to the publication number CN218653715U, a self-heating vacuum desorption waste gas treatment equipment is disclosed, which includes an adsorption tower, a vacuum pump, a condenser and a liquid storage tank; the adsorption tower includes a tower body and an inner shell inside, a jacket layer is formed between the tower body and the inner shell, and the inner shell and the jacket layer are filled with adsorbent; the side wall of the tower body is also provided with an inner air inlet, an inner exhaust port and an inner desorption port connected to the inner shell, an outer air inlet, an outer exhaust port and an outer desorption port connected to the jacket layer, and the inner desorption port and the outer desorption port are connected to the vacuum pump; the condenser is connected to the vacuum pump and the liquid storage tank; valves are installed on the inner air inlet, the inner exhaust port, the outer air inlet, the outer exhaust port and the desorption pipeline. Although the device can alternately carry out adsorption and desorption processes in the inner shell and the jacket layer, thereby reducing the system operation risk and reducing the operating energy consumption, the heat generated in this way has limited effect on the efficiency of adsorption and desorption. In addition, the heating is uneven depending on the position of the activated carbon, and the replacement of the adsorbent in the jacket layer is also cumbersome and inconvenient.

[0010] According to the publication number CN213901972U, a solar photovoltaic powered organic vapor condensation adsorption recovery system is disclosed, which includes a cover shell, a recovery box is fixedly connected to the bottom of the cover shell, and two fixed plates are fixedly connected to the top of the cover shell. The lower ends of the two fixed plates are fixedly connected to a fixed cylinder, and the side wall of the fixed cylinder close to the upper end is connected to an air duct, and the air duct runs through the side wall of the cover shell. The system can effectively utilize the waste heat generated during the condensation process, improve the utilization rate of energy, reduce enterprise costs, and can also scrape the organic liquid attached to the fixed cylinder into the recovery box, reducing the waste of resources, thereby improving the recovery effect of the device on organic vapor, and at the same time increasing the heat dissipation area of ​​the device, thereby improving the condensation efficiency. Although this method can effectively adsorb and recover organic vapor, it is only suitable for small-scale projects. Otherwise, if the adsorbed VOCs treatment volume is large or the concentration is high, the adsorbent will quickly be adsorbed and saturated. If the desorption process is not taken into account at this time, the adsorbent needs to be replaced frequently, greatly increasing the operating cost.

[0011] In summary, these adsorption and desorption devices and treatment methods in the existing adsorption and desorption technologies have various limitations in the field of adsorption and desorption of light hydrocarbon VOCs waste gas treatment, mainly including: complex process operation, limited treatment effect, difficulty in achieving the designed adsorption and desorption effects, cumbersome adsorbent replacement, relatively high investment and operating costs, and inability to achieve true energy conservation and carbon reduction.

[0012] Therefore, there is an urgent need to research and develop new adsorption and desorption devices for treating light hydrocarbon VOCs waste gas that can solve or avoid the above problems. Summary of the invention

[0013] In view of the shortcomings of the prior art, the present invention provides an adsorption and desorption device and a treatment method for treating waste gas containing light hydrocarbons VOCs, which solves the problems of unstable temperature control, high energy consumption, large equipment footprint and poor safety in the treatment process of waste gas containing light hydrocarbons VOCs.

[0014] To achieve the above objectives, the present invention is implemented through the following technical solutions: an adsorption and desorption device for treating light hydrocarbon VOCs waste gas, comprising an inlet flame arrester, one end of the inlet flame arrester is fixed with a light hydrocarbon VOCs waste gas inlet, the other end of the inlet flame arrester is respectively fixed with a plurality of induced draft fans through a Y-shaped pipeline, the induced draft fans are all fixed with an adsorption and desorption device through a pipeline, the adsorption and desorption device is internally provided with a plurality of functional layers, the functional layers include an adsorption and desorption layer, a heat preservation and cold preservation layer and a condensation heat exchange layer, the adsorption An oil-water separator is fixed inside the condensation heat exchange layer of the desorber through pipelines, a vacuum pump is provided on one side of the adsorption and desorption layers of the adsorption and desorber through pipelines, an outlet flame arrester is fixed on the other side of the adsorption and desorption layers of the adsorption and desorber through pipelines, an oil pump and a liquid infusion pump are respectively fixed inside the oil-water separator through Y-shaped pipelines, a cold water cold storage tank and a hot water heat preservation storage tank are respectively fixed inside the heat preservation and cold preservation layers of the adsorption and desorber through Y-shaped pipelines, and an energy supply component is provided on one side of the hot water heat preservation tank.

[0015] Preferably, the energy supply component includes an energy storage battery, a wind energy heating system and a solar energy heating system. The interior of the energy storage battery is connected to the hot water insulation storage tank through a Y-shaped pipeline, the interior of the wind energy heating system and the solar energy heating system are connected to the hot water insulation storage tank through a Y-shaped pipeline, and the interior of the wind energy heating system and the solar energy heating system are connected to the energy storage battery through a Y-shaped pipeline.

[0016] Preferably, the thermal insulation and cold preservation layers of the adsorption-desorber are both arranged in the middle part of the adsorption-desorber, the condensation heat exchange layer of the adsorption-desorber is both arranged on the outside of the thermal insulation and cold preservation layers of the adsorption-desorber, and the adsorption and desorption layers of the adsorption-desorber are both arranged on the inside of the thermal insulation and cold preservation layers of the adsorption-desorber.

[0017] Preferably, the heat-insulating and cold-insulating layers are connected to the cold-water cold-insulating storage tank and the hot-water heat-insulating storage tank by a Y-shaped pipe, and a regulating valve group is arranged inside.

[0018] Preferably, one end of the vacuum pump is connected to the adsorption and desorption layers of the adsorption-desorber, and the other end of the vacuum pump is connected to the inlet of the induced draft fan.

[0019] Preferably, the wind energy heating system and the solar energy heating system use wind energy and solar energy to collect heat from cold water and generate electricity.

[0020] Preferably, the energy storage battery storage medium includes but is not limited to lead-acid batteries, lithium-ion batteries and sodium-ion batteries.

[0021] Preferably, the condensation heat exchange layer and the heat preservation and cold insulation layer of the adsorption-desorber are all of seamless tank-type or hollow tube-type structure, and the adsorption and desorption layers are surrounded by fully closed, semi-closed, interval closed or irregular closed manner.

[0022] Preferably, the adsorption and desorption layers of the adsorption-desorber are both adsorbed by adsorbents, the types of which include but are not limited to activated carbon, molecular sieves, silica gel, alumina, ion exchange resins and metal organic frameworks MOFs, and the adsorbent styles include but are not limited to granular, columnar, spherical, sheet, strip and fiber;

[0023] The adsorption and desorption layers of the adsorption-desorber are both desorbed by vacuum pumps, and the types thereof include but are not limited to dry screw vacuum pumps, oil-sealed rotary vane vacuum pumps, oil-free scroll vacuum pumps, Roots vacuum pumps and liquid ring vacuum pumps.

[0024] An adsorption-desorption treatment method for treating waste gas containing light hydrocarbons VOCs comprises the following steps:

[0025] S1. The light hydrocarbon VOCs waste gas first passes through the inlet flame arrester, and then is led by the induced draft fan to the condensation heat exchange layer of the adsorption desorber to condense the light hydrocarbon VOCs waste gas; a part of the water and some VOCs components in the light hydrocarbon VOCs waste gas are removed, and the light hydrocarbon VOCs waste gas is cooled at the same time;

[0026] S2, passing the light hydrocarbon VOCs waste gas after condensation treatment into the oil-water separator for gas-liquid separation, recovering part of the oil phase and liquid phase, and then passing most of the condensed gas into the adsorption and desorption layers of the adsorption-desorber, so that they can be cross-continuously carried out, so that the adsorbent of each adsorption-desorber completes desorption and desorption and switches back to the adsorption state, completing a cycle;

[0027] S3. A large amount of adsorption heat is generated during adsorption, which will release heat, the adsorbent temperature will decrease, and the ambient temperature will increase. At this time, the pipeline is connected to the cold water storage tank, so that the pipelines of the heat preservation and cold preservation layers are filled with cold water, so as to continuously and stably reduce the ambient temperature of the adsorption desorber;

[0028] S4. After adsorption is completed, most of the organic components in the exhaust gas are adsorbed by the adsorbent. After the separated gas reaches the required pressure reduction, it enters the exhaust pipe through the outlet flame arrester and is discharged to the outside. The desorbed gas is returned to the induced draft fan inlet through the vacuum pump for circulation treatment;

[0029] S5. After the cyclic adsorption is completed, the adsorption inlet and outlet valves are closed, and the adsorption and desorption layers of the adsorption-desorber are switched to the desorption regeneration operation. At this time, they will begin to absorb heat, so that the adsorbent temperature increases and the ambient temperature decreases. At this time, the thermal insulation and cold insulation layer and the hot water thermal insulation storage tank are connected. The hot water thermal insulation storage tank can be connected to any one of the solar heating system, the wind heating system and the energy storage battery according to the situation to ensure that a continuous heat source can be obtained, so that the pipelines of the thermal insulation and cold insulation layers are filled with hot water, so as to increase the ambient temperature of the adsorption-desorber;

[0030] S6. After adsorption and desorption are completed, the temperature of the heat preservation and cold preservation layers, whether it is the hot water return during desorption or the cold water return during condensation adsorption, will increase and finally flow back to the hot water insulation storage tank to be heated to a certain temperature and then recycled repeatedly.

[0031] The present invention provides an adsorption-desorption device and a treatment method for treating waste gas containing light hydrocarbons (VOCs).

[0032] It has the following beneficial effects:

[0033] 1. The present invention adopts a unique adsorption-desorber structure design, including a triple structure of a condensation heat exchange layer, a heat preservation and cold preservation layer, and an adsorption and desorption layer, which not only greatly simplifies the pipeline layout, but also effectively reduces the footprint of the device and reduces the investment cost. This design makes the adsorption and desorption process more efficient and stable, especially in the adsorption stage, through the intelligent adjustment of the cold water cold preservation layer, the temperature control is guaranteed, and the safety hazards caused by high temperature are avoided. Compared with the cumbersome pipeline design in the prior art, it solves the problem of excessive space and investment costs.

[0034] 2. The present invention realizes green and clean energy supply by combining solar energy, wind energy heating system and energy storage battery, which not only reduces the dependence on traditional energy, but also ensures the stability of the desorption process through continuous heating. This energy combination ensures that the device can maintain sufficient heat supply during the desorption process, avoids the energy shortage problem existing in traditional heating systems, and reduces the demand for external energy, reducing overall energy consumption and operating costs.

[0035] 3. The present invention not only ensures the high efficiency of the waste gas treatment process, but also effectively reduces environmental pollution by combining the recycling system, condensation method, and adsorption and desorption method. The treated tail gas can meet strict emission standards, and the recovered products can be fully reused, reducing resource waste. Compared with the single treatment method in the prior art, the present invention achieves the dual goals of resource conservation and environmental friendliness by optimizing the treatment process and enhancing recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a distribution diagram of the device structure of the present invention;

[0037] Figure 2 It is a schematic diagram of the method steps of the present invention.

[0038] Among them, 101, inlet flame arrester; 102, induced draft fan; 103, adsorption desorber; 104, vacuum pump; 105, oil-water separator; 106, oil pump; 107, infusion pump; 108, cold water storage tank; 109, hot water storage tank; 110, energy storage battery; 111, wind heating system; 112, solar heating system; 113, outlet flame arrester. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Embodiment 1:

[0041] Please see attached Figure 1 The embodiment of the present invention provides an adsorption-desorption device for treating light hydrocarbon VOCs waste gas, including an inlet flame arrester 101, one end of the inlet flame arrester 101 is fixed with a light hydrocarbon VOCs waste gas inlet, the other end of the inlet flame arrester 101 is respectively fixed with a plurality of induced draft fans 102 through a Y-shaped pipeline, the induced draft fans 102 are all fixed with an adsorption-desorption device 103 through a pipeline, the adsorption-desorption device 103 is internally provided with a plurality of functional layers, the functional layers include an adsorption and desorption layer, a heat preservation and cold preservation layer and a condensation heat exchange layer, the condensation heat exchange layer of ... An oil-water separator 105 is fixed on the pipeline, a vacuum pump 104 is provided on one side of the adsorption and desorption layers of the adsorption and desorption device 103 through pipelines, an outlet flame arrester 113 is fixed on the other side of the adsorption and desorption layers of the adsorption and desorption device 103 through pipelines, an oil delivery pump 106 and a liquid delivery pump 107 are respectively fixed on the oil-water separator 105 through Y-shaped pipelines, a cold water cold storage tank 108 and a hot water heat preservation storage tank 109 are respectively fixed on the heat preservation and cold preservation layers of the adsorption and desorption device 103 through Y-shaped pipelines, and an energy supply component is provided on one side of the hot water heat preservation storage tank 109;

[0042] The energy supply component includes an energy storage battery 110, a wind energy heating system 111 and a solar energy heating system 112. The interior of the energy storage battery 110 is connected to the hot water insulation storage tank 109 through a Y-shaped pipeline. The interiors of the wind energy heating system 111 and the solar energy heating system 112 are connected to the hot water insulation storage tank 109 through a Y-shaped pipeline. The interiors of the wind energy heating system 111 and the solar energy heating system 112 are connected to the energy storage battery 110 through a Y-shaped pipeline.

[0043] The heat preservation and cold preservation layers of the adsorption-desorber 103 are both arranged in the middle of the adsorption-desorber 103, the condensation heat exchange layers of the adsorption-desorber 103 are both arranged outside the heat preservation and cold preservation layers of the adsorption-desorber 103, and the adsorption and desorption layers of the adsorption-desorber 103 are both arranged inside the heat preservation and cold preservation layers of the adsorption-desorber 103;

[0044] The heat preservation and cold preservation layer 103B is connected to the cold water cold preservation storage tank 108 and the hot water heat preservation storage tank 109 by a Y-shaped pipe, and a regulating valve group is arranged inside;

[0045] One end of the vacuum pump 104 is connected to the adsorption and desorption layers of the adsorption-desorption device 103, and the other end of the vacuum pump 104 is connected to the inlet of the induced draft fan 102;

[0046] The wind energy heating system 111 and the solar energy heating system 112 use wind energy and solar energy to collect heat from cold water and generate electricity;

[0047] Energy storage battery 110 storage media includes but is not limited to lead-acid batteries, lithium-ion batteries and sodium-ion batteries;

[0048] The condensation heat exchange layer and the heat preservation and cold preservation layer of the adsorption-desorber 103 are all of seamless tank-type or hollow tube-type structure, and the adsorption and desorption layers are all surrounded by a fully closed, semi-closed, interval closed or irregular closed manner;

[0049] The adsorption and desorption layers of the adsorption-desorber 103 are both adsorbed by adsorbents, the types of which include but are not limited to activated carbon, molecular sieves, silica gel, alumina, ion exchange resins and metal organic frameworks MOFs, and the adsorbent styles include but are not limited to granular, columnar, spherical, sheet, strip and fiber;

[0050] The adsorption and desorption layers of the adsorption-desorber 103 are both desorbed by vacuum pumps, and the types thereof include but are not limited to dry screw vacuum pumps, oil-sealed rotary vane vacuum pumps, oil-free scroll vacuum pumps, Roots vacuum pumps, and liquid ring vacuum pumps.

[0051] Specifically, the light hydrocarbon VOCs waste gas first passes through the inlet flame arrester 101 to prevent external fire sources from causing safety hazards to the system. Subsequently, the waste gas is transported to the condensation heat exchange layer of the adsorption desorber 103 by the induced draft fan 102. In this stage, the waste gas temperature is reduced to 5°C to 10°C through heat exchange condensation, thereby effectively reducing the moisture content therein and reducing the concentration of some VOCs components, thereby reducing the load of subsequent adsorption and desorption links. In addition, after the waste gas with a lower temperature enters the adsorption layer, it can avoid the decrease in adsorption efficiency due to excessive temperature rise during the adsorption process, thereby ensuring stable operation of the system.

[0052] After condensation and cooling, the airflow enters the oil-water separator 105 for gas-liquid separation. This process can recover some liquid hydrocarbon substances, in which the oil phase component is transported to the oil storage tank by the oil pump 106 for recovery, and the liquid phase component is transported to the sewage treatment system by the infusion pump 107 for subsequent treatment. The condensed gas after separation enters the adsorption and desorption layer of the adsorption desorber 103 for deep purification.

[0053] During the adsorption stage, the airflow passes through the adsorption-desorber 103 filled with adsorbent, wherein the VOCs components are captured by the adsorbent, so that the pollutant concentration of the exhaust gas is reduced to a range that meets the emission standards. In order to ensure the stability of the adsorption process, a large amount of heat will be released during the adsorption process, causing the adsorbent temperature to rise, which may affect its adsorption capacity. Therefore, the system connects the cold water cold storage tank 108 to allow low-temperature cold water to flow through the pipeline, thereby continuously reducing the temperature of the adsorption environment, preventing the adsorbent temperature from being too high, and ensuring the stability of the adsorption effect. At the same time, the cooling mechanism can also indirectly improve the efficiency of the condensation stage, making the early cooling effect better.

[0054] When the adsorbent reaches saturation, the system switches to desorption mode. At this time, the adsorbent inside the adsorption-desorber 103 needs to be regenerated by heating to release the adsorbed VOCs components so that it regains its adsorption capacity. Since the desorption process requires the absorption of a large amount of heat, the pipeline will switch to the hot water insulation storage tank 109 for heating. The heat source of hot water can come from the solar heating system 112, the wind heating system 111, or the electric heating system provided by the energy storage battery 110 to ensure the continuity of heat supply and make the desorption process more efficient and stable. In addition, the VOCs concentrated gas generated during the desorption process is extracted by the vacuum pump 104 and returned to the inlet of the induced draft fan 102 for circulation treatment, further reducing pollutant emissions.

[0055] The exhaust gas after adsorption and purification is discharged to the exhaust pipe through the outlet flame arrester 113 after pressure reduction and regulation, ensuring that the exhaust gas emission meets environmental protection standards. At the same time, in the entire circulation system, the cold water in the condensation adsorption stage and the hot water return water in the desorption process will flow back to the hot water insulation storage tank 109, and will be recycled after reheating, thereby improving energy utilization, reducing energy consumption, and ensuring the economy and environmental protection of the system.

[0056] Embodiment 2:

[0057] Please see attached Figure 2 , an adsorption and desorption treatment method for treating waste gas containing light hydrocarbons VOCs, comprising the following steps:

[0058] S1, the light hydrocarbon VOCs waste gas first passes through the inlet flame arrester 101, and then is led to the condensation heat exchange layer of the adsorption desorber 103 by the induced draft fan 102, and the light hydrocarbon VOCs waste gas is condensed; part of the water and part of the VOCs components in the light hydrocarbon VOCs waste gas are removed, and the light hydrocarbon VOCs waste gas is cooled;

[0059] S2, passing the light hydrocarbon VOCs waste gas after condensation treatment into the oil-water separator 105 for gas-liquid separation, recovering a part of the oil phase and the liquid phase, and then passing most of the condensed gas into the adsorption and desorption layers of the adsorption-desorber 103, so that they can be cross-continuously carried out, so that the adsorbent of each adsorption-desorber 103 completes desorption and desorption and switches back to the adsorption state, completing a cycle;

[0060] S3, a large amount of adsorption heat is generated during adsorption, which will release heat, the adsorbent temperature decreases, and the ambient temperature increases. At this time, the pipeline is connected to the cold water cold storage tank 108, so that the pipelines of the heat preservation and cold insulation layers are filled with cold water, so as to continuously and stably reduce the ambient temperature of the adsorption desorber 103;

[0061] S4. After the adsorption is completed, most of the organic components in the exhaust gas are adsorbed by the adsorbent. After the separated gas reaches the required decompression, it enters the exhaust pipe through the outlet flame arrester 113 and is discharged to the outside. The desorbed gas is returned to the inlet of the induced draft fan 102 through the vacuum pump 104 for circulation treatment;

[0062] S5. After the cyclic adsorption is completed, the adsorption inlet and outlet valves are closed, and the adsorption and desorption layers of the adsorption-desorber 103 are switched to the desorption regeneration operation. At this time, it will begin to absorb heat, so that the adsorbent temperature increases and the ambient temperature decreases. At this time, the heat preservation and cold preservation layer and the hot water heat preservation tank 109 are connected. The hot water heat preservation tank 109 can be connected to any one of the solar energy heating system 112, the wind energy heating system 111 and the energy storage battery 110 according to the situation to ensure that a continuous heat source can be obtained, so that the pipes of the heat preservation and cold preservation layers are filled with hot water, so as to increase the ambient temperature of the adsorption-desorber;

[0063] S6. After adsorption and desorption are completed, the temperature of the hot water return water during desorption and the cold water return water during condensation adsorption in the heat preservation and cold preservation layers will increase and finally flow back to the hot water heat preservation storage tank 109 to be heated to a certain temperature and then recycled repeatedly.

[0064] The specific steps and details of the method part are the same as those of the device part. For details, please refer to the embodiment part, and the specific details will not be repeated here.

[0065] Working principle: The light hydrocarbon VOCs waste gas first passes through the inlet flame arrester 101, and then is guided by the induced draft fan 102 to enter the condensation heat exchange layer of the adsorption desorber 103 for condensation treatment; the condensation treatment reduces the waste gas temperature to 5°C~10°C, removes part of the moisture and VOCs components, and reduces the load of the adsorption desorber 103; the condensed light hydrocarbon VOCs waste gas enters the oil-water separator 105 for gas-liquid separation, and after recovering the oil phase and liquid phase, most of the condensed gas is introduced into the adsorption and desorption layer of the adsorption desorber 103; each adsorption desorber 103 switches back to the adsorption state after completing desorption and desorption, completing a complete cycle; during adsorption, the pipeline is connected to the cold water cold storage tank 108, and the cold water cold storage tank 108 is connected to the cold water cold storage tank 108. Water flows through the pipeline to reduce the ambient temperature of the adsorber-desorber 103; during the desorption process, the pipeline is connected to the hot water insulation storage tank 109, and the hot water can be connected to the solar heating system 112, the wind heating system 111 or the energy storage battery 110 to provide a continuous heat source, ensuring that the hot water in the hot water insulation storage tank 109 fills the pipelines of the insulation and cold insulation layers, and the subsequent water flow can be returned to the hot water insulation storage tank 109 for reheating and recycling; the treated exhaust gas is discharged through the outlet flame arrester 113 to ensure that the exhaust gas meets the standards; the condensed oil tank is transported to the oil storage tank by the oil pump 106 for recycling; the condensed liquid phase is discharged to the sewage treatment system by the infusion pump 107 for subsequent treatment.

[0066] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An adsorption-desorption device for treating waste gas containing light hydrocarbons (VOCs), comprising an inlet flame arrester (101), characterized in that: An inlet for light hydrocarbon VOCs waste gas is fixed at one end of the inlet flame arrester (101), and a plurality of induced draft fans (102) are respectively fixed at the other end of the inlet flame arrester (101) through a Y-shaped pipeline. The induced draft fans (102) are all fixed with adsorption desorbers (103) through pipelines. The adsorption desorbers (103) are internally provided with a plurality of functional layers, and the functional layers include an adsorption and desorption layer, a heat preservation and cold preservation layer, and a condensation heat exchange layer. An oil-water separator (105) is fixed inside the condensation heat exchange layer of the adsorption desorber (103) through a pipeline. A vacuum pump (104) is provided on one side of the adsorption and desorption layers of the adsorbent-desorber (103) through a pipeline, an outlet flame arrester (113) is fixed on the other side of the adsorption and desorption layers of the adsorbent-desorber (103) through a pipeline, an oil delivery pump (106) and a liquid delivery pump (107) are fixed on the oil-water separator (105) through a Y-shaped pipeline, a cold water cold storage tank (108) and a hot water heat preservation storage tank (109) are fixed on the heat preservation and cold preservation layers of the adsorbent-desorber (103) through a Y-shaped pipeline, and an energy supply component is provided on one side of the hot water heat preservation storage tank (109).

2. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 1 is characterized in that: The energy supply component comprises an energy storage battery (110), a wind energy heating system (111) and a solar energy heating system (112); the interior of the energy storage battery (110) is connected to a hot water insulation storage tank (109) via a Y-shaped pipeline; the interiors of the wind energy heating system (111) and the solar energy heating system (112) are connected to the hot water insulation storage tank (109) via a Y-shaped pipeline; and the interiors of the wind energy heating system (111) and the solar energy heating system (112) are connected to the energy storage battery (110) via a Y-shaped pipeline.

3. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 1 is characterized in that: The heat preservation and cold preservation layers of the adsorption-desorber (103) are both arranged in the middle of the adsorption-desorber (103), the condensation heat exchange layer of the adsorption-desorber (103) is both arranged on the outside of the heat preservation and cold preservation layers of the adsorption-desorber (103), and the adsorption and desorption layers of the adsorption-desorber (103) are both arranged on the inside of the heat preservation and cold preservation layers of the adsorption-desorber (103).

4. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 1 is characterized in that: The heat preservation and cold preservation layers of the adsorption-desorber (103) are connected to the cold water cold preservation tank (108) and the hot water heat preservation tank (109) by a Y-shaped pipe, and a regulating valve group is arranged inside.

5. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 1 is characterized in that: One end of the vacuum pump (104) is connected to the adsorption and desorption layers of the adsorption-desorber (103), and the other end of the vacuum pump (104) is connected to the inlet of the induced draft fan (102).

6. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 2 is characterized in that: The wind energy heating system (111) and the solar energy heating system (112) use wind energy and solar energy to collect heat from cold water and generate electricity.

7. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 2 is characterized in that: The energy storage battery (110) storage medium includes but is not limited to lead-acid batteries, lithium-ion batteries and sodium-ion batteries.

8. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 1 is characterized in that: The condensation heat exchange layer and the heat preservation and cold insulation layer of the adsorption-desorber (103) are both of seamless tank-type or hollow tube-type structure, and the adsorption and desorption layers are both surrounded by a fully closed, semi-closed, interval-closed or irregularly closed manner.

9. The adsorption and desorption device for treating waste gas containing light hydrocarbons VOCs according to claim 1 is characterized in that: The adsorption and desorption layers of the adsorption-desorber (103) are both adsorbed by adsorbents, the types of which include but are not limited to activated carbon, molecular sieves, silica gel, alumina, ion exchange resins and metal organic frameworks MOFs, and the adsorbent forms include but are not limited to granular, columnar, spherical, sheet, strip and fibrous shapes; The adsorption and desorption layers of the adsorption-desorber (103) are both desorbed by using a vacuum pump, the types of which include but are not limited to a dry screw vacuum pump, an oil-sealed rotary vane vacuum pump, an oil-free vortex vacuum pump, a Roots vacuum pump and a liquid ring vacuum pump.

10. An adsorption-desorption method for treating waste gas containing light hydrocarbons VOCs, according to an adsorption-desorption device for treating waste gas containing light hydrocarbons VOCs according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, the light hydrocarbon VOCs waste gas first passes through the inlet flame arrester (101), and then is led by the induced draft fan (102) to the condensation heat exchange layer of the adsorption desorber (103), and the light hydrocarbon VOCs waste gas is condensed; a part of the water and part of the VOCs components in the light hydrocarbon VOCs waste gas are removed, and the light hydrocarbon VOCs waste gas is cooled; S2, passing the light hydrocarbon VOCs waste gas after condensation treatment into the oil-water separator (105) for gas-liquid separation, recovering a portion of the oil phase and the liquid phase, and then passing most of the condensed gas into the adsorption and desorption layers of the adsorption-desorber (103), so that they can be cross-continuously carried out, so that the adsorbent of each adsorption-desorber (103) completes desorption and desorption and switches back to the adsorption state, completing a cycle; S3, a large amount of adsorption heat is generated during adsorption, which will release heat, the adsorbent temperature decreases, and the ambient temperature increases. At this time, the pipeline is connected to the cold water cold storage tank (108), and the pipeline of the heat preservation and cold insulation layer is filled with cold water, so as to continuously and stably reduce the ambient temperature of the adsorption desorber (103); S4. After the adsorption is completed, most of the organic components in the waste gas are adsorbed by the adsorbent. After the separated gas reaches the required pressure reduction, it enters the exhaust pipe through the outlet flame arrester (113) and is discharged to the outside after reaching the standard. The desorbed gas returns to the inlet of the induced draft fan (102) through the vacuum pump (104) for circulation treatment; S5. After the cyclic adsorption is completed, the adsorption inlet and outlet valves are closed, and the adsorption and desorption layers of the adsorption-desorber (103) are switched to the desorption regeneration operation. At this time, they begin to absorb heat, causing the adsorbent temperature to rise and the ambient temperature to fall. At this time, the heat preservation and cold preservation layers are connected to the hot water heat preservation tank (109). The hot water heat preservation tank (109) can be connected to any one of the solar energy heating system (112), the wind energy heating system (111) and the energy storage battery (110) according to the situation to ensure that a continuous heat source can be obtained, so that the pipes of the heat preservation and cold preservation layers are filled with hot water, so as to increase the ambient temperature of the adsorption-desorber; S6. After adsorption and desorption are completed, the temperature of the hot water return water during desorption and the cold water return water during condensation adsorption in the heat preservation and cold preservation layers will increase and finally flow back to the hot water heat preservation storage tank (109) to be heated to a certain temperature and then recycled repeatedly.

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