A process for treating tail gas from methyl acetate storage tank

Abstract

The invention discloses a tail gas treatment process of a methyl acetate storage tank, belonging to the field of tail gas treatment equipment; the invention is used to solve the problems of difficulty in adaptively adjusting the internal space of the storage tank according to the amount of gas and low adsorption efficiency; the invention pre-treats the tail gas and performs multi-stage cooling to effectively improve the cooling effect of the tail gas, and forms an integrated process of condensation-adsorption with an adsorption system, thereby improving the treatment efficiency and treatment effect of the tail gas; at the same time, when the amount of treated gas increases, the linkage cooperation of an air bag and an electromagnet is utilized to expand the internal space of the adsorption tank, so that the internal pressure of the adsorption tank is kept stable, thereby greatly improving the safety during use, and adaptive adjustment of the internal space can be achieved without adopting additional equipment; while the internal space is expanded, the second cavity is connected with the adsorption layer, and at this time, the gas enters the adsorption layer from the top and surrounding of the adsorption layer, thereby increasing the contact area between the adsorption layer and the gas, thereby effectively improving the adsorption efficiency of the gas.

Description

Technical Field

[0001] The invention relates to the field of tail gas treatment equipment, and in particular to a tail gas treatment process for a methyl acetate storage tank. Background Art

[0002] Methyl acetate is an organic compound produced by the esterification reaction of acetic acid and methanol. Methyl acetate is often used in solvents, fragrances and some chemical synthesis reactions. In the production and processing of methyl acetate, it is often necessary to use storage tanks to store methyl acetate. During the storage process,

[0003] However, in the process of exhaust gas treatment, the adsorption characteristics of activated carbon are usually used to dispose of volatile organic compounds. However, activated carbon has defects such as frequent replacement and high cost in actual use.

[0004] In view of the above problems, the existing patent provides a VOCs tail gas treatment process (publication number: CN118437119A). The patent combines multiple equipment and pipelines to form a unified process flow facility, and uses multiple parallel adsorbers for adsorption, which effectively reduces the use of activated carbon, while reducing the cost of activated carbon and the generation of waste activated carbon.

[0005] However, in actual use of the above technical solution, the upper limit of the load per unit time of the adsorber is usually fixed. Therefore, when the amount of gas to be processed is large, it is often necessary to increase the number of adsorbers or perform multiple transport processes, which undoubtedly increases the cost of use and reduces the gas processing efficiency.

[0006] That is, it is difficult for the adsorber to adaptively adjust its internal space according to the gas volume, the adsorption efficiency is low, and it is difficult to meet various processing needs.

[0007] In view of the above technical defects, a solution is now proposed. Summary of the invention

[0008] The object of the present invention is to provide a methyl acetate storage tank tail gas treatment process to solve the technical defects proposed in the background technology.

[0009] The purpose of the present invention can be achieved by the following technical scheme: A methyl acetate storage tank tail gas treatment process comprises the following steps:

[0010] Step 1: transport the tail gas to a gas-liquid separation tank through a pipeline to obtain liquid material and gas material;

[0011] Step 2: The liquid material is transported to a temporary storage tank through a pipeline, and the gas material is transported to a precooler through a pipeline, and the internal temperature of the precooler is reduced to 5-10°C to obtain a primary gas product;

[0012] Step 3: The gaseous product is transported to the primary condenser through a pipeline. The internal temperature of the primary condenser is -20~-30°C. Liquid material and residual gas are obtained. The liquid material is transported to a temporary storage tank through a pipeline.

[0013] Step 4: transport the remaining gas to the secondary condenser through a pipeline, the internal temperature of the secondary condenser is -60~-75°C, and obtain liquid material and final gas;

[0014] Step 5: The final gas is transported to the adsorption system for adsorption and desorption cycle treatment.

[0015] Preferably, the adsorption system in step five comprises a plurality of adsorption tanks, and the adsorption tanks are fixedly connected to the secondary condenser via pipelines.

[0016] Preferably, the adsorption tank includes a tank body, a sealing plate and an adsorption layer, the sealing plate is movably installed in the tank body, the adsorption layer is fixedly installed inside the tank body, the sealing plate is located above the adsorption layer, an air outlet pipe is fixedly installed at the bottom of the tank body, and the air outlet pipe is fixedly connected to the precooler.

[0017] Preferably, a cavity one is provided inside the tank body, a sealing plate is movably installed in the cavity one, two sealing plates are symmetrically provided, and the sealing plates enclose to form a gas channel.

[0018] Preferably, an airbag is fixedly installed in cavity one, the airbag is fixedly connected to the sealing plate, an air supply pipe is fixedly installed on one side of the airbag, a fixed tube is fixedly installed inside cavity one, one end of the fixed tube extends to the inside of the airbag, a moving rod is movably installed inside the fixed tube, one end of the moving rod is abutted against the sealing plate, a spring is sleeved on the moving rod, and both ends of the spring are respectively fixedly connected to the inner wall of the airbag and the fixed tube.

[0019] Preferably, a cavity 2 is provided inside the tank body, a through groove is opened on the top of the cavity 2, and the cavity 2 is connected with the interior of the cavity 1 through the through groove. A plurality of baffles are movably installed in the cavity 2, and the adsorption layer is located in the middle of the baffle. A plurality of electromagnets are fixedly installed on the inner wall of the cavity 2, and a magnetic block is fixedly installed on the baffle, and the positions of the electromagnets and the magnetic blocks are adapted to each other.

[0020] Preferably, multiple vertical rods are fixedly installed in cavity 2, and the vertical rods are movably connected to the baffle through a spiral spring. A contact block is fixedly installed inside the fixed tube, and the contact block is located at the end of the moving rod away from the sealing plate. The contact block is electrically connected to the electromagnet.

[0021] Preferably, the desorption method in step five is: using a vacuum pump to extract the tail gas adsorbed in the adsorption tank and transport it to the precooler through a circulation pipe.

[0022] Preferably, a transverse tube is fixedly installed in the precooler, the circulation tube is fixedly connected to the transverse tube, mixing chambers are arranged at intervals on the transverse tube, and the gas delivery pipe is fixedly connected to the mixing chamber.

[0023] The beneficial effects of the present invention are as follows:

[0024] (1) The present invention uses a precooler, a primary condenser and a secondary condenser in combination. The precooler is first used to control the tail gas temperature, which effectively reduces the difficulty of subsequent treatment equipment. At the same time, a multi-stage cooling method is adopted to effectively improve the tail gas cooling effect. At the same time, an integrated condensation-adsorption process is formed with the adsorption system, thereby improving the tail gas treatment efficiency and treatment effect.

[0025] (2) The present invention sets up an adsorption system. When the amount of processed gas increases, the airbag contracts to drive the sealing plate to move. At this time, the internal space of the adsorption tank is expanded by using the first cavity and the second cavity, so that the internal pressure of the adsorption tank is kept stable, which greatly improves the safety during use. In addition, the adaptive adjustment of the internal space can be achieved without using additional equipment.

[0026] At the same time, after the airbag shrinks, the electromagnet is used to drive the baffle to move, so that the second cavity is connected with the adsorption layer. At this time, the gas enters the adsorption layer from the top and around the adsorption layer, increasing the contact area between the adsorption layer and the gas, thereby effectively improving the gas adsorption efficiency and meeting multiple processing needs at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings;

[0028] Figure 1 It is a schematic diagram of the process flow of the present invention;

[0029] Figure 2 It is a structural schematic diagram of the adsorption tank in the present invention;

[0030] Figure 3 It is a structural schematic diagram of the tank body in the present invention;

[0031] Figure 4 is a cross-sectional view of the adsorption tank in the present invention;

[0032] Figure 5 It is a structural schematic diagram of the sealing plate in the present invention;

[0033] Figure 6 It is a structural schematic diagram of the through slot in the present invention;

[0034] Figure 7 It is a schematic diagram of the structure of the cavity 2 in the present invention;

[0035] Figure 8 It is a structural schematic diagram of the baffle in the present invention;

[0036] Fig. 9 It is a schematic diagram of the structure of the fixed pipe in the present invention;

[0037] Fig.10It is a structural schematic diagram of the transverse tube in the present invention.

[0038] Legend: 1. Gas-liquid separation tank; 2. Temporary storage tank; 3. Precooler; 301. Horizontal tube; 302. Mixing chamber; 4. Primary condenser; 5. Secondary condenser; 6. Adsorption system; 601. Adsorption tank; 602. Tank body; 603. Sealing plate; 604. Adsorption layer; 605. Air outlet pipe; 606. Cavity one; 607. Air bag; 608. Air pipe; 609. Fixed pipe; 610. Moving rod; 611. Cavity two; 612. Through groove; 613. Baffle; 614. Electromagnet; 615. Magnetic block; 616. Vertical rod; 617. Contact block; 618. Circulation pipe. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments 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] See also Figure 1 - Figure 6 As shown, this embodiment is a methyl acetate storage tank tail gas treatment process, comprising the following steps:

[0042] Step 1: transport the tail gas to the gas-liquid separation tank 1 through a pipeline to obtain liquid material and gas material;

[0043] Step 2: transport the liquid material to the temporary storage tank 2 through the pipeline, and transport the gas material to the precooler 3 through the pipeline, and reduce the internal temperature of the precooler 3 to 5-10°C to obtain the primary gas product;

[0044] Step 3: The gaseous product is transported to the primary condenser 4 through a pipeline. The internal temperature of the primary condenser 4 is -20 to -30°C. Liquid material and residual gas are obtained. The liquid material is transported to the temporary storage tank 2 through a pipeline.

[0045] Step 4: transport the remaining gas to the secondary condenser 5 through a pipeline, the internal temperature of the secondary condenser 5 is -60~-75°C, and obtain liquid material and final gas;

[0046] The precooler 3 is specifically a heat exchanger, through which the exhaust gas temperature is adjusted. At the same time, the internal temperature of the precooler 3 is determined according to actual needs. In this embodiment, the temperature of the precooler 3 is 6°C to achieve the best treatment effect. After the pretreatment is completed, the primary gas is transported to the primary condenser 4 through a pipeline.

[0047] In this embodiment, the internal temperature of the primary condenser 4 is -25°C, and the internal temperature of the secondary condenser 5 is -70°C. The primary gas product is cooled multiple times by the primary condenser 4 and the secondary condenser 5. During the cooling process, the methyl acetate in the gas is gradually condensed into liquid and gathered at the bottom of the primary condenser 4 and the secondary condenser 5, and is transported to the temporary storage tank 2 through the bottom pipelines of the primary condenser 4 and the secondary condenser 5 for unified collection and treatment.

[0048] First, the exhaust gas temperature is controlled by the precooler 3, which effectively reduces the processing difficulty of subsequent equipment. At the same time, a multi-stage cooling method is adopted to effectively improve the exhaust gas cooling effect. At the same time, an integrated condensation-adsorption process is formed with the adsorption system 6, which improves the treatment efficiency and treatment effect of the exhaust gas from the methyl acetate storage tank.

[0049] Embodiment 2:

[0050] See also Figure 7 - Fig.10 As shown, the present invention also includes step five, transporting the final gas to the adsorption system 6 for adsorption and desorption cycle treatment, wherein the adsorption system 6 includes a plurality of adsorption tanks 601, and the adsorption tanks 601 are fixedly connected to the secondary condenser 5 through pipelines. In this embodiment, two adsorption tanks 601 are provided, and the alternating adsorption and desorption treatment of the two adsorption tanks 601 ensures the continuity of the treatment work.

[0051] The adsorption tank 601 includes a tank body 602, a sealing plate 603 and an adsorption layer 604. The sealing plate 603 is movably installed in the tank body 602, the adsorption layer 604 is fixedly installed inside the tank body 602, the sealing plate 603 is located above the adsorption layer 604, and an outlet pipe 605 is fixedly installed at the bottom of the tank body 602, and the outlet pipe 605 is used to discharge the remaining gas.

[0052] A cavity 606 is provided inside the tank body 602 , and a sealing plate 603 is movably installed in the cavity 606 . Two sealing plates 603 are symmetrically provided to enclose a gas channel. An airbag 607 is fixedly installed in the cavity 606 , and the airbag 607 is fixedly connected to the sealing plate 603 .

[0053] A gas pipe 608 is fixedly installed on one side of the airbag 607, and a fixed tube 609 is fixedly installed inside the cavity 606. One end of the fixed tube 609 extends to the inside of the airbag 607. A moving rod 610 is movably installed inside the fixed tube 609. One end of the moving rod 610 is abutted against the sealing plate 603. A spring is sleeved on the moving rod 610. Both ends of the spring are fixedly connected to the inner wall of the airbag 607 and the fixed tube 609 respectively. When the internal pressure of the tank body 602 increases, the gas in the airbag 607 is extracted through the gas pipe 608.

[0054] The pressure is collected by a pressure sensor fixedly installed in the tank body 602. Conventional detection mechanisms such as barometers are fixedly installed on the pipelines, which are all existing technologies. Their structures and connection methods are not described here, and they are not drawn in the figure. When the gas in the airbag 607 is extracted, the airbag 607 shrinks, and the two sealing plates 603 gradually separate. At this time, the through groove 612 is in an open state, and the cavity one 606 and the cavity two 611 are connected. The gas enters the cavity two 611 through the through groove 612, which effectively relieves the bearing pressure of the cavity one 606 and ensures the stability of the internal pressure of the tank body 602.

[0055] When the amount of processed gas increases, the airbag 607 contracts to drive the sealing plate 603 to move. At this time, the internal space of the adsorption tank 601 is expanded by using cavity 1 606 and cavity 2 611, so that the internal pressure of the adsorption tank 601 remains stable, which greatly improves the safety during use and can realize adaptive adjustment of the internal space without using additional equipment.

[0056] At the same time, when the gas is extracted from the airbag 607, since the temperature inside the tank 602 is low, the gas temperature is also low, and the gas is transported to the mixing chamber 302 through the gas pipe 608, effectively improving the exhaust gas pretreatment efficiency.

[0057] The specific way in which the gas pipe 608 is fixedly connected to the precooler 3 is as follows: a cross pipe 301 is fixedly installed inside the precooler 3, and the exhaust gas is transported to the precooler 3 for cooling treatment through the cross pipe 301, wherein the circulation pipe 618 is fixedly connected to the cross pipe 301, and a mixing chamber 302 is arranged at intervals on the cross pipe 301, and the gas pipe 608 is fixedly connected to the mixing chamber 302.

[0058] The specific principle is as follows: when the exhaust gas flows in the cross pipe 301, the desorbed gas enters the cross pipe 301 through the circulation pipe 618 and mixes with the exhaust gas in the cross pipe 301 to reduce the temperature of the exhaust gas. When the mixed exhaust gas flows to the mixing chamber 302, the gas in the gas pipe 608 is sprayed in and collides and mixes with the mixed exhaust gas. On the one hand, the air mass is dispersed to ensure uniform cooling of the exhaust gas. On the other hand, the mixed exhaust gas is further cooled by the gas with lower temperature, thereby reducing the workload of the precooler 3, realizing the internal circulation recovery of the cooling amount, and improving the exhaust gas pretreatment efficiency.

[0059] A cavity 2 611 is provided inside the tank body 602, a through slot 612 is provided on the top of the cavity 2 611, the cavity 2 611 is connected with the interior of the cavity 1 606 through the through slot 612, a plurality of baffles 613 are movably installed in the cavity 2 611, the adsorption layer 604 is located in the middle of the baffle 613, a plurality of electromagnets 614 are fixedly installed on the inner wall of the cavity 2 611, a magnetic block 615 is fixedly installed on the baffle 613, and the positions of the electromagnet 614 and the magnetic block 615 are adapted to each other.

[0060] A plurality of vertical rods 616 are fixedly installed in the second cavity 611, and the vertical rods 616 are movably connected to the baffle 613 through a spiral spring. The specific connection method is: a spiral spring, that is, a spiral structure with elastic deformation ability, is fixedly installed on the vertical rod 616, and its inner circle is fixedly connected to the vertical rod 616, and then the baffle 613 is fixedly connected to the outer wall of the spiral spring. Under the elastic force of the spiral spring, the blocks are tightly fitted. The spiral spring is a prior art, and its specific structure and connection method are not described here, and it is not drawn in the figure.

[0061] In the initial state, the electromagnet 614 is not energized and has no magnetism. At this time, under the action of the spiral spring, the baffles 613 are tightly connected to each other, thereby isolating the second cavity 611 from the adsorption layer 604. When the electromagnet 614 is energized to generate magnetism, under the action of magnetic force, the baffle 613 rotates around the vertical rod 616 as the axis, and the spiral spring gradually shrinks. When the electromagnet 614 is powered off, under the action of the spiral spring, the baffle 613 is reset to isolate the second cavity 611 from the adsorption layer 604 again.

[0062] A contact block 617 is fixedly installed inside the fixed tube 609. The contact block 617 is located at the end of the moving rod 610 away from the sealing plate 603. The contact block 617 is electrically connected to the electromagnet 614. When the airbag 607 shrinks, under the action of the internal pressure of the tank body 602, the sealing plate 603 pushes the moving rod 610 to move toward the contact block 617, and the spring is gradually compressed. When the moving rod 610 moves to the end of the fixed tube 609, it is squeezed and contacted with the contact block 617. At this time, the electromagnet 614 is energized to generate a magnetic field, and the magnetic block 615 is pulled toward the electromagnet 614 by magnetic force. At this time, the second cavity 611 is connected to the adsorption layer 604.

[0063] Specifically, after the airbag 607 shrinks, the electromagnet 614 is used to drive the baffle 613 to move, so that the cavity 2 611 is connected with the adsorption layer 604. At this time, the gas enters the adsorption layer 604 from the top and the surrounding of the adsorption layer 604, thereby increasing the contact area between the adsorption layer 604 and the gas, thereby effectively improving the adsorption efficiency of the gas and meeting multiple processing needs at the same time.

[0064] In combination with Example 1 and Example 2, the exhaust gas cooling effect is effectively improved by pre-treating and multi-stage cooling of the exhaust gas, and an integrated condensation-adsorption process is formed with the adsorption system 6, thereby improving the exhaust gas treatment efficiency and treatment effect. At the same time, when the amount of treated gas increases, the linkage cooperation of the airbag 607 and the electromagnet 614 is utilized to expand the internal space of the adsorption tank 601, so that the internal pressure of the adsorption tank 601 remains stable, which greatly improves the safety during use, and the adaptive adjustment of the internal space can be achieved without the use of additional equipment. While the internal space is expanded, the cavity 2 611 is connected to the adsorption layer 604. At this time, the gas enters the adsorption layer 604 from the top and around the adsorption layer 604, thereby increasing the contact area between the adsorption layer 604 and the gas, thereby effectively improving the gas adsorption efficiency, and can meet multiple treatment needs at the same time.

[0065] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A methyl acetate storage tank tail gas treatment process, characterized in that: The following steps are involved: Step 1: transporting the tail gas to a gas-liquid separation tank (1) through a pipeline to obtain liquid material and gas material; Step 2: transporting the liquid material to the temporary storage tank (2) through a pipeline, and transporting the gas material to the precooler (3) through a pipeline, and reducing the internal temperature of the precooler (3) to 5-10° C. to obtain a gaseous primary product; Step 3: The gaseous product is transported to the primary condenser (4) through a pipeline. The internal temperature of the primary condenser (4) is -20 to -30°C. Liquid material and residual gas are obtained. The liquid material is transported to the temporary storage tank (2) through a pipeline. Step 4: transport the remaining gas to the secondary condenser (5) through a pipeline, wherein the internal temperature of the secondary condenser (5) is -60 to -75°C, to obtain liquid material and final gas; Step 5: transporting the final gas to the adsorption system (6) for adsorption and desorption cycle treatment; The adsorption system (6) in step five comprises a plurality of adsorption tanks (601), wherein the adsorption tanks (601) are fixedly connected to the secondary condenser (5) via pipelines; The desorption method in step 5 is: using a vacuum pump to extract the tail gas adsorbed in the adsorption tank (601), and transporting it to the precooler (3) through the circulation pipe (618); The adsorption tank (601) comprises a tank body (602), a sealing plate (603) and an adsorption layer (604), wherein the sealing plate (603) is movably installed in the tank body (602); The adsorption layer (604) is fixedly installed inside the tank body (602), the sealing plate (603) is located above the adsorption layer (604), and an air outlet pipe (605) is fixedly installed at the bottom of the tank body (602); The tank body (602) is provided with a cavity one (606) inside, the sealing plate (603) is movably installed in the cavity one (606), two sealing plates (603) are symmetrically arranged, and the sealing plates (603) are enclosed to form a gas channel; An air bag (607) is fixedly installed in the cavity (606), the air bag (607) is fixedly connected to the sealing plate (603), and an air delivery pipe (608) is fixedly installed on one side of the air bag (607); A fixed tube (609) is fixedly installed inside the cavity (606), one end of the fixed tube (609) extends into the airbag (607), a moving rod (610) is movably installed inside the fixed tube (609), one end of the moving rod (610) is against the sealing plate (603), a spring is sleeved on the moving rod (610), and two ends of the spring are fixedly connected to the inner wall of the airbag (607) and the fixed tube (609) respectively; The tank body (602) is provided with a second cavity (611) inside, and a through groove (612) is provided on the top of the second cavity (611). The second cavity (611) is connected with the inside of the first cavity (606) through the through groove (612). When the pressure inside the tank body (602) increases, the gas in the airbag (607) is extracted through the gas pipe (608). When the gas in the airbag (607) is extracted, the airbag (607) contracts, and the two sealing plates (603) are gradually separated. At this time, the through groove (612) is in an open state, and the first cavity (606) and the second cavity (611) are connected. The gas enters the second cavity (611) through the through groove (612); A plurality of baffles (613) are movably installed in the second cavity (611), the adsorption layer (604) is located in the middle of the baffles (613), a plurality of electromagnets (614) are fixedly installed on the inner wall of the second cavity (611), a magnetic block (615) is fixedly installed on the baffles (613), and the positions of the electromagnets (614) and the magnetic blocks (615) are matched.

2. A methyl acetate storage tank tail gas treatment process according to claim 1, characterized in that: A plurality of vertical rods (616) are fixedly installed in the second cavity (611), and the vertical rods (616) are movably connected to the baffle (613) through a spiral spring. A contact block (617) is fixedly installed inside the fixed tube (609), and the contact block (617) is located at one end of the moving rod (610) away from the sealing plate (603), and the contact block (617) is electrically connected to the electromagnet (614).

3. A methyl acetate storage tank tail gas treatment process according to claim 2, characterized in that: A transverse tube (301) is fixedly installed in the precooler (3), the circulation tube (618) is fixedly connected to the transverse tube (301), a mixing chamber (302) is arranged at intervals on the transverse tube (301), and the gas delivery pipe (608) is fixedly connected to the mixing chamber (302).

Images