Reaction kettle tail gas recovery treatment device

Abstract

The utility model discloses a reaction kettle tail gas recovery processing device which comprises a reaction kettle tail gas pipe, a buffer tank and a solution recovery tank, the buffer tank is provided with a first inlet, a second inlet and a discharge port, and the first inlet is communicated with the reaction kettle tail gas pipe; the condensation recoverer is provided with a tail gas inlet, a liquid outlet and a gas outlet, the tail gas inlet is communicated with the discharge port of the buffer tank, and the liquid outlet is communicated with the solution recovery tank; the gas permeable membrane separation device is formed by connecting more than two membrane groups in series or in parallel, and is provided with a mixed gas inlet, a concentrated gas outlet and a discharged tail gas outlet, the mixed gas inlet is communicated with the gas outlet of the condensation recoverer, and the concentrated gas outlet is communicated with the second inlet of the buffer tank. Condensation recovery and gas membrane separation recovery are integrated, energy conservation and emission reduction are achieved, VOCs gas and air are separated and recovered through a membrane system, energy consumption is low, efficiency is high, after-membrane tail gas treatment concentration is low, the gas amount is small and stable, and follow-up tail gas treatment stably reaches the standard.

Description

Technical Field

[0001] The utility model relates to a tail gas recovery and treatment device, in particular to a tail gas recovery and treatment device for a reaction kettle. Background Art

[0002] Environmental pollution is becoming increasingly serious and has attracted more and more attention. Various environmental protection technologies have emerged one after another. However, many environmental protection technologies still need to be tested in practice. When selecting treatment technologies, advanced, mature, reliable and investment-saving technologies must be adopted.

[0003] The fine chemical industry widely uses kettle reactors as production process devices and produces under positive pressure, atmospheric pressure or negative pressure. Along with the reaction process, a large amount of high-concentration and low-air-volume VOCs gases (volatile organic compounds, English name: Volatile Organic Compounds) will be discharged. Taking the production process of DEHA (diethylhydroxylamine) as an example, there is a large amount of triethylamine in the tail gas of the reaction kettle during production that needs to be treated; the pharmaceutical industry widely uses acetone and dichloromethane, and there is a large amount of tail gas in the tail gas of the reaction kettle during production that needs to be treated. Traditional reaction kettle VOCs tail gas recovery devices have problems such as large investment, high energy consumption, low recovery efficiency, high instantaneous air volume, large gas flow fluctuation, and generation of waste liquid and hazardous waste. Specifically as follows:

[0004] At present, the treatment of triethylamine in the tail gas of the reaction kettle generally adopts a single method, which mainly includes four methods. First, condensation recovery, its cost investment and operation energy consumption cost are low, there is no waste output and no safety hazard, but the effective recovery rate is about 80%; second, cryogenic recovery, there is no waste output, and the effective recovery rate is about 90%, but the cost investment and operation energy consumption cost are high, and low-temperature crystallization is easy to block the pipeline; third, activated carbon / resin adsorption recovery, its cost investment and operation energy consumption cost are high, waste liquid and hazardous waste are generated during the recovery process, there is no explosion protection, and the effective recovery rate is about 70%. Content of the Utility Model

[0005] The purpose of the utility model is to provide a reaction kettle tail gas recovery and treatment device with reasonable structure, low input cost, high efficiency, energy saving and emission reduction.

[0006] The purpose of the utility model is realized as follows:

[0007] A reactor tail gas recovery and treatment device includes a reactor tail gas pipe, a buffer tank, and a solution recovery tank. The buffer tank is provided with a first inlet, a second inlet, and a discharge outlet. The first inlet is communicated with the reactor tail gas pipe. It further includes a condensation recovery device, which is provided with a tail gas inlet, a liquid outlet, and a gas outlet. The tail gas inlet is communicated with the discharge outlet of the buffer tank, and the liquid outlet is communicated with the solution recovery tank; a gas permeable membrane separation device, which is composed of two or more membrane groups connected in series or in parallel. It is provided with a mixed gas inlet, a concentrated gas outlet, and a discharged tail gas outlet. The mixed gas inlet is communicated with the gas outlet of the condensation recovery device, and the concentrated gas outlet is communicated with the second inlet of the buffer tank. The reactor process has an atmospheric pressure or reduced pressure reaction, accompanied by stirring or heating, and releases a large amount of tail gas.

[0008] The object of the present utility model can also be solved by the following technical measures:

[0009] As a more specific solution, a vacuum pump is further connected between the concentrated gas outlet and the second inlet.

[0010] As a further solution, the membrane group of the gas permeable membrane separation device includes a housing, a perforated central tube, and a permeation layer. The outer wall of the perforated central tube is provided with a plurality of through holes. The permeation layer includes multiple membrane bags and a permeating gas flow channel layer. The multiple membrane bags and the permeating gas flow channel layer are stacked at intervals and wound around the outer periphery of the perforated central tube. The membrane bag includes a concentrated gas flow channel layer and a membrane sheet. The concentrated gas flow channel layer is wrapped outside the membrane sheet; the housing is wrapped outside the perforated central tube, the multiple membrane bags, and the permeating gas flow channel layer. One end of the housing corresponding to the permeation layer and one end of the perforated central tube are respectively provided with the discharged tail gas outlet and the concentrated gas outlet, and the other end of the housing corresponding to the permeation layer is provided with the mixed gas inlet; the respective mixed gas inlets, concentrated gas outlets, and discharged tail gas outlets corresponding to each membrane group are respectively communicated to form a parallel connection.

[0011] As a further solution, the first inlet, the second inlet, and the discharge outlet are arranged at the top of the buffer tank.

[0012] As a further solution, the discharged tail gas outlet is connected to a post-membrane tail gas treatment system.

[0013] The VOCs gas source of the reactor is mainly organic solvents, such as alkanes (n-hexane, n-heptane, gasoline, diesel, etc.), alcohols (methanol, ethanol, propanol, butanol, isoamyl alcohol, etc.), ketones (acetone, butanone, isopentanone, etc.), ethers (diethyl ether, butyl ether, isopropyl ether, methyl isobutyl ether, etc.), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.), benzene rings (benzene, toluene, xylene, etc.), esters (ethyl acetate, butyl acetate, etc.), organic amines (triethylamine, diisopropylamine, etc.), which are organic substances that are liquid at room temperature, volatile, have a relatively high saturated vapor pressure, and a relatively low recovery rate.

[0014] As a further solution, the post-membrane tail gas treatment system is any one or more of a semiconductor catalytic device, a spray tower water washing device, an adsorption device, a regenerative thermal oxidation (RTO) device, or an incineration (TO) device.

[0015] The beneficial effects of the present utility model are as follows:

[0016] (1) This reactor tail gas recovery and treatment device first passes the tail gas of the kettle reactor through a buffer tank to separate entrained liquid, remove possible entrained mechanical impurities, and play a role in stabilizing the system and reducing mutual influence. The gas at the top of the buffer tank enters the tail gas condenser. The tail gas is condensed in the condenser to recover part of the solvent, realizing solvent recovery, reducing the tail gas load entering the membrane separation system, and reducing the scale of the membrane separation system device.

[0017] (2) The gas condensed by this reactor tail gas recovery and treatment device enters the membrane separation system device (gas permeation membrane separation device). The enriched recovered tail gas is circulated back to the buffer tank through a vacuum pump to converge with the workshop tail gas; the tail gas after membrane treatment enters the subsequent VOCs tail gas treatment system.

[0018] (3) This reactor tail gas recovery and treatment device combines condensation recovery and gas membrane separation recovery, saving energy and reducing emissions. The membrane system separates and recovers VOC gases from air, with low energy consumption and high efficiency. The concentration of the tail gas after membrane treatment is low, the gas volume is small and stable, which helps the subsequent tail gas treatment to meet the standards stably. This recovery process has no waste liquid or hazardous waste, does not require heating and desorption, does not contact with air, has no high-pressure deep cooling, and can be integrated in a skid-mounted manner. Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the present utility model.

[0020] Figure 2 It is a schematic structural diagram of a partially cut-open membrane group in the present utility model.

[0021] Figure 3 It is a schematic structural diagram of the gas permeation membrane separation device of the present utility model. Detailed Embodiments

[0022] The present utility model will be further described below in conjunction with the drawings and embodiments:

[0023] See Figures 1 to 3As shown in the figure, a reaction kettle tail gas recovery and treatment device includes a reaction kettle tail gas pipe 11, a buffer tank 2, and a solution recovery tank 4. The buffer tank 2 is provided with a first inlet, a second inlet, and a discharge port. The first inlet is communicated with the reaction kettle tail gas pipe 11. The device further includes a condensation recovery device 3, which is provided with a tail gas inlet, a liquid outlet, and a gas outlet. The tail gas inlet is communicated with the discharge port of the buffer tank 2, and the liquid outlet is communicated with the solution recovery tank 4; a gas permeable membrane separation device 5, which is composed of more than two membrane groups 50 connected in parallel. The device is provided with a mixed gas inlet 51, a concentrated gas outlet 52, and a discharged tail gas outlet 53. The mixed gas inlet 51 is communicated with the gas outlet of the condensation recovery device 3, and the concentrated gas outlet 52 is communicated with the second inlet of the buffer tank 2.

[0024] The membrane group 50 of the gas permeable membrane separation device 5 includes a housing, a perforated central tube 54, and a permeation layer 55. The outer wall of the perforated central tube 54 is provided with a number of through holes. The permeation layer 55 includes multiple membrane bags and a permeating gas flow channel layer. The multiple membrane bags and the permeating gas flow channel layer are stacked at intervals and wound around the outer periphery of the perforated central tube. The membrane bag includes a concentrated gas flow channel layer and a membrane sheet. The concentrated gas flow channel layer is wrapped outside the membrane sheet; the housing is wrapped outside the perforated central tube, the multiple membrane bags, and the permeating gas flow channel layer. One end of the housing corresponding to the permeation layer 55 and one end of the perforated central tube are respectively provided with the discharged tail gas outlet 53 and the concentrated gas outlet 52, and the other end of the housing corresponding to the permeation layer 55 is provided with the mixed gas inlet 51; the respective mixed gas inlets 51, concentrated gas outlets 52, and discharged tail gas outlets 53 corresponding to each membrane group 50 are respectively communicated to form a parallel connection (parallel connection in this embodiment, actually it can also be a series connection).

[0025] The housing includes a front end cover 57, a tube barrel 56, and a rear end cover 58. The tube barrel 56 is connected between the front end cover 57 and the rear end cover 58. The mixed gas inlet 51 is arranged on the front end cover 57, and the concentrated gas outlet 52 and the discharged tail gas outlet 53 are arranged on the rear end cover 58.

[0026] The gas permeable membrane separation device 5 (membrane separation system) is a prior art. The principle of recovering organic gas is to use the different selective permeability of polymer membrane materials to organic gas molecules and air molecules to achieve physical separation of the two. Under the driving of the pressure difference on both sides of the membrane, the organic gas and air mixture follows the solution-diffusion mechanism, so that the organic gas in the mixed gas preferentially permeates through the membrane and is enriched and recovered, while the air is selectively intercepted, so that clean air with organic gas removed is obtained on the intercepted side of the membrane, and enriched organic gas is obtained on the permeating side of the membrane, achieving the separation of organic gas and air. The mixed gas enters the membrane group from the mixed gas inlet 51 on the outer side of one end of the membrane group. After the permeation of the membrane sheet layer, the discharged gas flows out of the discharged tail gas outlet 53 from the side gap of the outer side of the other end, and the permeated concentrated permeating gas is discharged from the concentrated gas outlet 52 of the central tube of the membrane separation system.

[0027] The first inlet, the second inlet, and the discharge outlet are arranged at the top of the buffer tank 2.

[0028] The exhaust gas discharge outlet 53 is connected to the post-membrane exhaust gas treatment system.

[0029] The post-membrane exhaust gas treatment system is any one or more of a semiconductor catalytic device, a spray tower water washing device, an adsorption device, a regenerative thermal oxidizer (RTO), or an incinerator (TO) device.

[0030] Semiconductor catalytic device: The post-membrane exhaust gas can pass through the semiconductor catalytic device. Through UVALED irradiation, on a foam ceramic-based honeycomb ceramic-based micron-sized anatase titanium dioxide, after efficiently decomposing the low-concentration VOCs in the post-membrane gas, it is discharged up to the standard.

[0031] Spray tower water washing device: The post-membrane exhaust gas can pass through the spray tower water washing device for pickling and alkali washing, and then be discharged up to the standard.

[0032] Adsorption device: The post-membrane exhaust gas can be adsorbed by an activated carbon or silicon-based mesoporous material adsorption device and then be discharged up to the standard.

[0033] Its working principle is as follows: The tail gas C from the reactor 1 of the autoclave reactor first enters the buffer tank 2. The buffer tank 2 separates the liquid entrained in the tail gas, removes the possible entrained mechanical impurities, and plays a role in stabilizing the system and reducing mutual influence. The solvent liquid is regularly discharged from the bottom of the buffer tank, and the gas at the top of the buffer tank enters the condensation recovery device 3 through the discharge outlet. Part of the solvent is condensed and recovered in the condensation recovery device 3 for solvent recovery, and the tail gas load entering the gas permeation membrane separation device 5 is reduced, reducing the scale of the gas permeation membrane separation device 5.

[0034] The gas after being condensed by the condensation recovery device 3 enters the gas permeation membrane separation device 5. The enriched recovered tail gas is circulated back to the buffer tank 2 through the vacuum pump 6 to be mixed with the workshop tail gas; the tail gas after membrane treatment enters the subsequent VOCs tail gas treatment system.

[0035] The following combines data to illustrate its effects: Before treatment, the VOCs air volume is 5 - 500 m³ / h, and the concentration is 3000 - 300000 mg / m³. After the membrane separation system, the VOCs air volume is 0.1 - 2 m³ / h, and the concentration is 10 - 5000 mg / m³, and the recovery efficiency exceeds 95%.

[0036] The above is the preferred solution of the present utility model, which shows and describes the basic principle, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A reaction kettle tail gas recovery and treatment device, comprising a reaction kettle tail gas pipe (11), a buffer tank (2) and a solution recovery tank (4). The buffer tank (2) is provided with a first inlet, a second inlet and an outlet. The first inlet is communicated with the reaction kettle tail gas pipe (11), and it is characterized in that: It further comprises a condensation recovery device (3), which is provided with a tail gas inlet, a liquid outlet and a gas outlet. The tail gas inlet is communicated with the outlet of the buffer tank (2), and the liquid outlet is communicated with the solution recovery tank (4); A gas permeable membrane separation device (5), which is formed by connecting two or more membrane groups (50) in series or in parallel. It is provided with a mixed gas inlet (51), a concentrated gas outlet (52) and an exhaust tail gas outlet (53). The mixed gas inlet (51) is communicated with the gas outlet of the condensation recovery device (3), and the concentrated gas outlet (52) is communicated with the second inlet of the buffer tank (2).

2. The reactor tail gas recovery and treatment device according to claim 1, wherein: A vacuum pump (6) is further connected between the concentrated gas outlet (52) and the second inlet.

3. The reactor tail gas recovery and treatment device according to claim 1, characterized in that: The membrane group (50) of the gas permeable membrane separation device (5) comprises a housing, a perforated central pipe (54) and a permeation layer (55). A plurality of through holes are provided on the outer wall of the perforated central pipe (54). The permeation layer (55) comprises multiple membrane bags and a permeation gas flow channel layer. The multiple membrane bags and the permeation gas flow channel layer are stacked at intervals and wound around the outer periphery of the perforated central pipe. The membrane bag comprises a concentrated gas flow channel layer and a membrane sheet, and the concentrated gas flow channel layer is wrapped outside the membrane sheet; The housing is wrapped outside the perforated central pipe, the multiple membrane bags and the permeation gas flow channel layer. One end of the housing corresponding to the permeation layer (55) and one end of the perforated central pipe are respectively provided with the exhaust tail gas outlet (53) and the concentrated gas outlet (52), and the other end of the housing corresponding to the permeation layer (55) is provided with the mixed gas inlet (51); The respective mixed gas inlets (51), concentrated gas outlets (52) and exhaust tail gas outlets (53) corresponding to each membrane group (50) are respectively communicated to form a parallel connection.

4. The reactor tail gas recovery and treatment device according to claim 3, characterized in that: The first inlet, the second inlet and the outlet are arranged at the top of the buffer tank (2).

5. The reactor tail gas recovery and treatment device according to claim 1, characterized in that: The exhaust tail gas outlet (53) is connected to a post-membrane tail gas treatment system.

6. The reactor tail gas recovery and treatment device according to claim 5, characterized in that: The post-membrane tail gas treatment system is any one or more of a semiconductor catalytic device, a spray tower water washing device, an adsorption device, a regenerative thermal oxidation RTO or an incineration TO device.

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