CN113318468A - Production system for removing VOC (volatile organic compounds) from polyether polyol - Google Patents
Production system for removing VOC (volatile organic compounds) from polyether polyol Download PDFInfo
- Publication number
- CN113318468A CN113318468A CN202110528640.XA CN202110528640A CN113318468A CN 113318468 A CN113318468 A CN 113318468A CN 202110528640 A CN202110528640 A CN 202110528640A CN 113318468 A CN113318468 A CN 113318468A
- Authority
- CN
- China
- Prior art keywords
- tower
- stripping
- polyether
- section
- flash
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000004721 Polyphenylene oxide Substances 0.000 title claims abstract description 100
- 229920000570 polyether Polymers 0.000 title claims abstract description 100
- 229920005862 polyol Polymers 0.000 title claims abstract description 39
- 150000003077 polyols Chemical class 0.000 title claims abstract description 39
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 35
- 239000012855 volatile organic compound Substances 0.000 title abstract description 24
- 239000007789 gas Substances 0.000 claims abstract description 64
- 238000000926 separation method Methods 0.000 claims abstract description 10
- 239000007788 liquid Substances 0.000 claims description 36
- 238000012856 packing Methods 0.000 claims description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 11
- 239000000945 filler Substances 0.000 claims description 11
- 229920006395 saturated elastomer Polymers 0.000 claims description 8
- 239000000463 material Substances 0.000 claims description 7
- 230000009467 reduction Effects 0.000 claims description 6
- 239000011148 porous material Substances 0.000 claims description 5
- 238000004891 communication Methods 0.000 claims description 4
- 230000008676 import Effects 0.000 claims description 4
- 239000011261 inert gas Substances 0.000 claims description 4
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 238000003795 desorption Methods 0.000 claims 1
- 238000000034 method Methods 0.000 abstract description 22
- 230000008569 process Effects 0.000 abstract description 15
- 239000002912 waste gas Substances 0.000 abstract description 7
- 238000010924 continuous production Methods 0.000 abstract description 3
- 238000004134 energy conservation Methods 0.000 abstract description 3
- 239000012535 impurity Substances 0.000 abstract description 3
- 230000009466 transformation Effects 0.000 abstract description 3
- 239000002699 waste material Substances 0.000 abstract description 3
- 239000012071 phase Substances 0.000 description 23
- 239000000126 substance Substances 0.000 description 9
- 239000007791 liquid phase Substances 0.000 description 6
- 239000004814 polyurethane Substances 0.000 description 6
- 229920002635 polyurethane Polymers 0.000 description 6
- 238000004364 calculation method Methods 0.000 description 5
- 238000001704 evaporation Methods 0.000 description 5
- 230000008020 evaporation Effects 0.000 description 5
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 4
- 230000002349 favourable effect Effects 0.000 description 4
- 238000007701 flash-distillation Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 238000000605 extraction Methods 0.000 description 3
- 239000007921 spray Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 239000003595 mist Substances 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 description 1
- 229920002334 Spandex Polymers 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000005815 base catalysis Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000009189 diving Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000004759 spandex Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000009736 wetting Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/06—Flash distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/10—Vacuum distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/34—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping with one or more auxiliary substances
- B01D3/38—Steam distillation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/42—Regulation; Control
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Polyethers (AREA)
Abstract
The invention discloses a production system for removing VOC (volatile organic compounds) from polyether polyol, which belongs to the technical field of polyether polyol production and comprises a stripping tower, a flash tower, an outward-feeding pump and a vacuum unit, wherein the stripping tower comprises a deceleration section, a stripping section and a first tower kettle section which are sequentially arranged from top to bottom, the flash tower comprises a separation section, a flash section and a second tower kettle section which are sequentially arranged from top to bottom, and the top of the stripping tower is provided with a polyether inlet before removal and a gas phase outlet. The method has strong adaptability to the existing production process of the polyether polyol, and does not need other transformation; continuous production, more energy conservation and high efficiency; no other impurities are introduced into the product, and a complex subsequent treatment process is not needed; the VOC after the removal exists in the form of waste gas, the gas quantity is low, the method is suitable for various existing waste gas treatment processes, the process adaptability of three-waste treatment is strong, and the method is worthy of popularization and application.
Description
Technical Field
The invention relates to the technical field of polyether polyol production, in particular to a production system for removing VOC (volatile organic compounds) from polyether polyol.
Background
Polyether polyols are important raw materials for the polyurethane industry. The application fields of polyurethane products are quite wide, and the polyurethane products can be used for interior parts of automobiles, trains, ships, airplanes and the like, mattresses, sofas, chairs, bedding, carpets, building energy-saving heat-insulating materials, sealing materials and waterproof materials. The polyurethane product is used for the heat insulating material of household appliances such as refrigerator, electric appliance shell, insulating device, package, and synthetic fiber, namely spandex, which can be used for manufacturing high-grade sportswear, diving suit and the like.
With the enhancement of environmental awareness and the improvement of living standard, the environmental requirements for living goods are more and more strict, and particularly, polyurethane industrial products taking polyether polyol as a raw material are widely applied to scenes with frequent close contact with people, and the raw material with high VOC content inevitably causes heavy smell of the products, influences the use comfort and also causes harm to the environment and human bodies. Meanwhile, products with high volatile organic content and high odor also limit the application of polyether polyol products in high-end polyurethane terminal products, and have great influence on the product quality. VOC removal by polyether polyol and low-odor production of products become difficult problems for various large polyether polyol manufacturers.
The traditional polyether polyol production process is a strong base catalysis process, a batch reactor is adopted, the odor generated in the product is mainly caused by side reaction in the reaction process of raw material propylene oxide, and aldehyde substances are generated by reaction under the action of a strong base catalyst. Accordingly, a production system for VOC removal of polyether polyols is proposed.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: how to solve the problems of limited removal effect, long operation period, difficulty in removal and the like of the existing method for removing VOC by polyether polyol, and provides a production system for removing VOC by polyether polyol.
The invention solves the technical problems by the following technical scheme, the invention comprises a stripping tower, a flash tower, an external pump and a vacuum unit, wherein the stripping tower comprises a deceleration section, a stripping section and a first tower kettle section which are sequentially arranged from top to bottom, the flash tower comprises a separation section, a flash section and a second tower kettle section which are sequentially arranged from top to bottom, the tower top of the stripping tower is provided with a pre-stripping polyether inlet and a gas phase outlet, pre-stripping polyether is input into the stripping tower through the pre-stripping polyether inlet, the gas phase outlet is connected with the vacuum unit, the tower bottom of the stripping tower is provided with a polyether outlet and a stripping gas inlet, stripping gas is input into the stripping tower through the stripping gas inlet, the tower top of the flash tower is provided with a polyether inlet and a gas phase outlet, the polyether inlet is connected with the pre-stripping polyether inlet, and the gas phase outlet is connected with the vacuum unit, and a post-removal polyether outlet is arranged at the bottom of the flash tower and is connected with the outward-feeding pump.
Furthermore, the production system also comprises two groups of heat tracing components, wherein the heat tracing components are externally sleeved or externally heat tracing pipes, saturated steam is used for heat tracing, and the heat tracing components are respectively arranged on the stripping tower and the flash tower.
Still further, the production system further comprises two sets of pressure control loops and two sets of liquid level control loops, wherein the pressure control loops are arranged at the top of the stripping tower/the flash tower, and the liquid level control loops are arranged at the bottom of the stripping tower/the flash tower.
Further, the pressure control loop includes pressure sensor and pressure-controlled valve, pressure sensor sets up the strip tower/the top of flash column, pressure-controlled valve sets up strip tower/flash column with on the pipeline between the vacuum unit, pressure sensor and pressure-controlled valve communication connection, the liquid level control loop includes level gauge and pilot operated valve, the level gauge sets up strip tower/the bottom of the flash column, the pilot operated valve set up at the polyether import with take off preceding polyether import/send the output pipeline of pump outward on, level gauge and pilot operated valve communication connection.
Furthermore, the pressure control range of the pressure sensor on the stripping tower is 8-20 Pa, and the pressure control range of the pressure sensor on the flash tower is 2-8 Pa.
Furthermore, the ratio of the speed reduction section to the stripping section of the stripping tower is 1.2: 1-2: 1.
Still further, the stripping column further comprises a first demister, a first feed distributor, two stages of packing, a gas phase distributor; the first demister and the first feeding distributor are both arranged in the deceleration section, and the pre-dewatering polyether inlet is connected with the first feeding distributor; the two sections of the fillers are sequentially arranged in the stripping section; the gas phase distributor is arranged in the first tower kettle section.
Still further, the flash column further comprises a second demister, a second feed distributor, and a section of packing, both the second demister and the second feed distributor being disposed in the separation section; the second feed distributor is connected to a polyether inlet, and the packing is disposed in the flash section.
Furthermore, the packing materials in the stripping tower and the flash tower are porous materials, and the specific surface area is 100-800 square meters per m3。
Furthermore, the temperature of the polyether-removing forward tower of the stripping tower is 100-200 ℃, and the stripping gas of the stripping tower is inert gas.
Compared with the prior art, the invention has the following advantages: the production system for removing VOC from polyether polyol has strong adaptability to the existing production process of polyether polyol, and does not need other transformation; continuous production, more energy conservation and high efficiency; no other impurities are introduced into the product, and a complex subsequent treatment process is not needed; the VOC after the removal exists in the form of waste gas, the gas quantity is low, the method is suitable for various existing waste gas treatment processes, the process adaptability of three-waste treatment is strong, and the method is worthy of popularization and application.
Drawings
FIG. 1 is a schematic flow chart of the VOC removal process for polyether polyol in example two of the present invention.
Detailed Description
The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.
Example one
A production system for removing VOC (volatile organic compounds) from polyether polyol comprises a stripping tower, a flash tower, an external pump and a vacuum unit;
the stripping column comprises three parts, a deceleration section, a stripping section and a column bottom section. An external sleeve or an external heat tracing pipe is arranged, and saturated steam of 0.1-1.0 MPa (G) is used for heat tracing, and in the embodiment, the saturated steam of 0.2-0.5 MPa (G) is preferably used.
Wherein the ratio of the diameter of the deceleration section to the diameter of the stripping section is 1.2: 1-2: 1. The speed reduction section is used for reducing the gas speed of the empty tower, reducing entrainment and improving the product yield, the selection of the diameter ratio is calculated and selected according to the size of entrainment liquid drops, the removal of gas phase is ensured to leave the tower body, and the polyether glycol product is left in the tower, so that the product loss is reduced.
In this example, the velocity reduction section of the stripping column contains a demister, which is used to further remove entrained mist from the gas phase. A suitable demister product can be selected by calculation from the gas-liquid phase data.
In this example, the velocity reduction stage of the stripping column comprises a feed distributor for uniformly distributing the feed polyether polyol over the column cross-section. And selecting a proper feed distributor product by calculation according to the feed amount and the tower diameter.
The stripping section of the stripping tower comprises two sections of packing, the stripping section is a main gas-liquid contact section in the stripping process, the sufficient specific surface area is favorable for gas-liquid phase separation, but the pressure drop is increased, and the stripping process is not favorable. The filler can be selected from proper porous materials, random fillers or regular fillers, and the specific surface area is 100-800 square meters per m3The preferred specific surface area is 200 to 500 square meters per meter3。
In this embodiment, the stripping section of the stripping column also needs to be provided with necessary internals and redistributors, such as packing press plates, support plates, redistributors, etc.
Wherein the tower bottom section of the stripping tower comprises a gas phase distributor and a tower bottom, and is used for gas phase distribution and containing polyether products.
In this example, a gas phase distributor is used to distribute the stripping gas uniformly over the column cross section. The appropriate gas phase distributor can be selected by calculation according to the gas phase quantity and the tower diameter.
In this embodiment, the tower still needs a certain liquid level height to ensure the convenience of operation.
The stripping column should contain at least 2 critical control loops, a pressure control loop and a liquid level control loop.
Wherein the pressure control circuit comprises a pressure sensor and a pressure controlled valve.
In this embodiment, the pressure sensor is located at the top of the stripping tower, and the control range is 8-20 pa (a), preferably 10-15 pa (a), and the adjustability of the pressure at the top of the stripping tower is realized by adjusting the amount of vacuumized gas.
Wherein the liquid level control loop comprises a liquid level meter and a liquid control valve.
In this embodiment, the level gauge is located the tower cauldron section, and control keeps 50% tower cauldron liquid level, and the stability of operation can be guaranteed to abundant liquid seal, prevents the UNICOM of stripper and flash column pressure, influences the normal operation of tower system.
The stripping tower at least comprises 4 material medium interfaces, a pre-stripping polyether inlet, a polyether outlet, a gas phase outlet and a stripping gas inlet.
In this example, the polyether removal inlet and the stripping gas inlet comprise suitable distribution means to ensure uniform distribution of the gas-liquid phase across the column cross-section.
The flash tower comprises three parts, a separation section, a flash evaporation section and a tower kettle section. An external sleeve or an external heat tracing pipe is arranged, saturated steam of 0.1-1.0 MPa (G) is used for heat tracing, and preferably, the saturated steam of 0.2-0.5 MPa (G) is used.
Wherein the installation height of the flash tower is required to ensure that the height of a polyether inlet pipe orifice of the flash tower is lower than that of a polyether outlet pipe orifice of the stripping tower, so that the polyether inlet pipe orifice can automatically flow into the flash tower through pressure difference, a pump for conveying is reduced, and the production energy consumption is reduced.
Wherein, the separation section of the flash tower is used for separating flash evaporation gas and entrained spray.
In this example, the separation section of the flash column contains a demister for further removal of entrained mist from the gas phase. A suitable demister product can be selected by calculation from the gas-liquid phase data.
In this example, the separation section of the flash column contains a feed distributor for uniformly distributing the feed polyether polyol across the column cross-section. And selecting a proper feed distributor product by calculation according to the feed amount and the tower diameter.
Wherein the flash distillation section of flash column includes one section filler, and the porous filler of mainly used polyether glycol fully wets is favorable to dissolving gaseous flash distillation, and the flash distillation section is the main place of flash process, and abundant specific surface is favorable to the abundant wetting of liquid phase, does benefit to the flash distillation, but the pressure drop can increase, is unfavorable for the flash process on the contrary. The filler can be selected from proper porous materials, random fillers or regular fillers, and the specific surface area is 100-800 square meters per m3The preferred specific surface area is 200 to 500 square meters per meter3。
In this embodiment, the flash evaporation section of the flash evaporation tower needs to be provided with necessary internals and redistribution devices, such as packing press plates, support plates, collectors and the like.
Wherein the tower kettle section of the flash tower is used for containing polyether products. The tower still needs a certain liquid level height to ensure the convenience of operation.
The flash tower at least comprises 2 key control loops, a pressure control loop and a liquid level control loop.
Wherein the pressure control circuit comprises a pressure sensor and a pressure controlled valve.
In this embodiment, the pressure sensor is located at the top of the flash tower, and the control range is 2-8 pa (a), preferably 2-5 pa (a), and the adjustability of the pressure at the top of the flash tower is realized by adjusting the amount of vacuumized gas.
Wherein the liquid level control loop comprises a liquid level meter and a liquid control valve.
In this embodiment, the level meter is located at the tower bottom section, and controls to maintain 50% of the tower bottom liquid level, and the sufficient liquid seal can ensure the stability of operation, ensure the sufficient net liquid level height of the outward-feeding pump, and prevent the pump from cavitation and affecting the normal operation of the tower system.
The flash tower at least comprises 3 material medium interfaces, a polyether inlet, a stripped polyether outlet and a gas phase outlet.
In this example, the polyether inlet contains suitable distribution means to ensure uniform distribution of the gas-liquid phase over the column cross-section. The post-strip polyether outlet contains a suitable vortex breaker.
The outward-feeding pump is a chemical process pump, and proper flow and lift are selected according to operation conditions.
Wherein the installation height of the external pump is ensured to meet the vacuum breaking requirement by the height from the lowest liquid level of the flash tower.
The vacuum unit has a cooling function, and is mainly used for cooling, separating and removing soluble organic matters and condensate carried in a gas phase, so that the soluble organic matters and the condensate are prevented from entering the vacuum unit and influencing the operation.
In this embodiment, the vacuum unit should select a proper amount of air extraction according to the amount of treated polyether, VOC content of products of different grades, and the amount of stripping gas, and ensure that the ultimate vacuum is not more than 2pa (a).
The working principle of the embodiment is as follows:
the temperature of polyether (polyether polyol) before stripping entering a stripping tower is 100-200 ℃, preferably 140-180 ℃, and after entering a stripping section of the stripping tower, the polyether (polyether polyol) enters a stripping section of the stripping tower, and is in countercurrent contact with stripping gas in the stripping tower, and the polyether (polyether polyol) flows out from the bottom of the stripping tower through a hydraulic control loop. Stripping column stripping gas enters from the bottom of the column, and inert gas can be used as stripping gas, in this example superheated steam and nitrogen are used. Wherein the superheated steam is preferably 0.2-1.0 MPa (G) superheated steam with the temperature of 150-250 ℃; the nitrogen gas is preferably 0.1 to 0.7MPa (G) nitrogen gas. The gas-liquid ratio range of the superheated steam of the stripping gas is 1: 5-1: 20 (mass ratio, the same below), and the gas-liquid ratio range of the nitrogen gas is as follows: 1: 10-1: 30; the preferable gas-liquid ratio ranges from 1:8 to 1:15 (superheated steam) and from 1:15 to 1:25 (nitrogen). The stripping gas enters a stripping tower, is uniformly distributed on the cross section of the tower through a gas distributor, and is in countercurrent contact with the polyether before stripping in a stripping section. The stripping tower controls the air extraction amount through a tower top pressure control loop, and extracts the stripping gas and the small molecular substances with odor dissolved in the polyether before stripping. Polyether at the bottom of the stripping tower enters the top of the flash tower and is uniformly distributed on the cross section of the flash tower through a liquid distributor, the filler in the flash tower is a porous material, the large specific surface area increases an evaporation surface, the air extraction amount and the vacuum degree are controlled through a pressure control loop at the top of the tower, the small molecular substances with odor and the stripping gas dissolved in the small molecular substances are ensured to be fully evaporated, and the property of the polyether after stripping is ensured.
Example two
As shown in figure 1, the production system for removing VOC from polyether polyol comprises a stripping tower C-101, a flash tower C-102, an outward-conveying pump P-101 and a vacuum unit P-102.
The stripping tower is provided with three sections, namely a speed reduction section 1-I, a stripping section 1-II and a tower kettle section 1-III in sequence, and at least comprises four material ports, at least comprises 1 pressure control loop 11 and 1 liquid level control loop 16.
If necessary, the stripping tower is provided with a pre-polyether inlet 18 and a gas phase outlet 17 at the top and a polyether outlet 19 and a stripping gas inlet 110 at the bottom.
Before the removal, polyether enters a stripping tower from the top of the tower, stripping gas enters the stripping tower from the bottom of the tower, and countercurrent contact is carried out in the stripping tower to remove the odorous micromolecule substances. The polyether flows from the bottom through a level control loop 16, the gas phase being withdrawn from the top.
In this example, the polyether feed temperature to the column before removal was 150 ℃.
In this example, the stripping gas was selected as superheated steam at a pressure of 1MPa (G) and a temperature of 250 ℃ in a gas-liquid ratio of 1: 10.
In this example, the first stage packing 14 and the second stage packing 15 in the stripping sections 1-II of the stripping column were each selected to have a specific surface area of 250 square meters per meter (m)3The structured packing of (1).
In this example, the ratio of the diameter of the stripper deceleration section 1-I to the stripping section 1-II is 1.5: 1.
In this embodimentIn the middle, the demister 12 is a wire mesh demister made of S30408 and having a wire mesh density of 150kg/m3And porosity 0.975.
In this example, the feed distributor 13 was a nozzle type liquid distributor with a spray density of 8m3/㎡·h。
In the present embodiment, the gas phase distributor 111 selects an open gas inlet pipe.
In this example, the stripping column top pressure was controlled at 15Pa (A).
In this example, the stripper column used 0.4MPa (G) saturated steam for external heat tracing.
The flash tower is provided with three sections, namely a separation section 2-I, a flash section 2-II and a tower kettle section 2-III in sequence, and at least comprises 3 material ports, at least comprises 1 pressure control loop 21 and 1 liquid level control loop 25.
According to requirements, a polyether inlet 27 and a gas phase outlet 26 are arranged at the top of the flash tower, and a post-stripping polyether outlet 28 is arranged at the bottom of the flash tower.
Polyether enters a flash tower from the top of the tower, is fully wetted in a flash section in the tower, and is subjected to vacuum pumping to remove odorous micromolecular substances and dissolved stripping gas. The polyether after stripping flows out from the bottom of the tower through a liquid level control loop 25, and the gas phase is extracted from the top of the tower.
In this example, the packing 24 in the flash stages 2-II is selected to be a structured packing having a specific surface area of 250 square meters per m 3.
In this embodiment, the demister 22 is a wire mesh demister made of S30408 and having a wire mesh density of 150kg/m3And porosity 0.975.
In this example, the feed distributor 23 was a nozzle type liquid distributor with a spray density of 8m3/㎡·h。
In this example, the flash column head pressure was controlled at 3Pa (A).
In this example, the flash column used 0.4MPa (G) saturated steam for external heat tracing.
In the embodiment, the polyether after being removed is pressurized and sent to a subsequent working section by an external pump, and then is cooled and stored.
In the present embodiment, the external pump is a centrifugal pump.
In this embodiment, the gas phase pumped out by the two towers enters a vacuum unit, cooling is performed firstly, the condensate is separated, the non-condensable gas enters the vacuum unit, and the desorbed gas is finally sent to the waste gas treatment equipment for treatment.
In the embodiment, the vacuum unit is a roots + water ring vacuum unit.
The production system of the embodiment is adopted for processing, the odor of the removed polyether is detected, the concentration of characteristic substances which possibly generate odor in the product is selected for detection, and the result is shown in table 1.
Table 1 VOC removing effect table of this example
Remarking: the results of the measurement of the odor-causing characteristic substances in the polyether products are selected in table 1 and are reported in ppm.
The comparison shows that the production system can effectively remove the peculiar smell in the polyether polyol product, and the characteristic substances which possibly generate the peculiar smell are all effectively removed.
In conclusion, the production system for removing VOC from polyether polyol has strong adaptability to the existing production process of polyether polyol, and does not need other transformation; continuous production, more energy conservation and high efficiency; no other impurities are introduced into the product, and a complex subsequent treatment process is not needed; the VOC after the removal exists in the form of waste gas, the gas quantity is low, the method is suitable for various existing waste gas treatment processes, and the process adaptability of three-waste treatment is strong.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (10)
1. A production system for polyether polyol desorption VOC which characterized in that: comprises a stripping tower, a flash tower, an external pump and a vacuum unit, wherein the stripping tower comprises a deceleration section, a stripping section and a first tower kettle section which are sequentially arranged from top to bottom, the flash tower comprises a separation section, a flash section and a second tower kettle section which are sequentially arranged from top to bottom, the tower top of the stripping tower is provided with a polyether inlet before stripping and a gas phase outlet, polyether before stripping is input into the stripping tower from the polyether inlet before stripping, the gas phase outlet is connected with the vacuum unit, the bottom of the stripping tower is provided with a polyether outlet and a stripping gas inlet, stripping gas is input into the stripping tower through the stripping gas inlet, the top of the flash tower is provided with a polyether inlet and a gas phase outlet, the polyether inlet is connected with the polyether inlet before removal, the gas phase outlet is connected with the vacuum unit, a post-removal polyether outlet is arranged at the bottom of the flash tower, and the post-removal polyether outlet is connected with the outward-feeding pump.
2. A production system for VOC removal of polyether polyols according to claim 1, wherein: the production system also comprises two groups of heat tracing components, the heat tracing components are externally sleeved or externally heat tracing pipes, saturated steam is used for heat tracing, and the heat tracing components are respectively arranged on the stripping tower and the flash tower.
3. A production system for VOC removal of polyether polyol according to claim 2, wherein: the production system also comprises two groups of pressure control loops and two groups of liquid level control loops, wherein the pressure control loops are arranged at the top of the stripping tower/the flash tower, and the liquid level control loops are arranged at the bottom of the stripping tower/the flash tower.
4. A production system for VOC removal of polyether polyols according to claim 3, wherein: the pressure control circuit includes pressure sensor and pressure-controlled valve, pressure sensor sets up strip tower/the top of the tower of flash column, pressure-controlled valve sets up strip tower/flash column with on the pipeline between the vacuum unit, pressure sensor and pressure-controlled valve communication connection, the liquid level control circuit includes level gauge and pilot operated valve, the level gauge sets up strip tower/the bottom of the tower of flash column, the pilot operated valve set up at the polyether import with take off preceding polyether import/send the output pipeline of pump outward on, level gauge and pilot operated valve communication connection.
5. A production system for VOC removal of polyether polyols according to claim 4, wherein: the pressure control range of the pressure sensor on the stripping tower is 8-20 Pa, and the pressure control range of the pressure sensor on the flash tower is 2-8 Pa.
6. A production system for VOC removal of polyether polyols according to claim 1, wherein: the ratio of the speed reduction section to the stripping section of the stripping tower is 1.2: 1-2: 1.
7. A production system for VOC removal of polyether polyols according to claim 1, wherein: the stripping tower also comprises a first demister, a first feeding distributor, two sections of packing and a gas phase distributor; the first demister and the first feeding distributor are both arranged in the deceleration section, and the pre-dewatering polyether inlet is connected with the first feeding distributor; the two sections of the fillers are sequentially arranged in the stripping section; the gas phase distributor is arranged in the first tower kettle section.
8. A production system for VOC removal of polyether polyols according to claim 7, wherein: the flash tower further comprises a second demister, a second feeding distributor and a section of packing, and the second demister and the second feeding distributor are arranged in the separation section; the second feed distributor is connected to a polyether inlet, and the packing is disposed in the flash section.
9. A production system for VOC removal of polyether polyols according to claim 8, wherein: the packing materials in the stripping tower and the flash tower are porous materials, and the specific surface area is 100-800 square meters per meter3。
10. A production system for VOC removal of polyether polyols according to claim 1, wherein: the temperature of the advanced polyether removal tower of the stripping tower is 100-200 ℃, the stripping gas of the stripping tower is inert gas, the inert gas is superheated steam or nitrogen, the gas-liquid ratio of the superheated steam is 1: 5-1: 20, and the gas-liquid ratio of the nitrogen is as follows: 1: 10-1: 30.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110528640.XA CN113318468A (en) | 2021-05-14 | 2021-05-14 | Production system for removing VOC (volatile organic compounds) from polyether polyol |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110528640.XA CN113318468A (en) | 2021-05-14 | 2021-05-14 | Production system for removing VOC (volatile organic compounds) from polyether polyol |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113318468A true CN113318468A (en) | 2021-08-31 |
Family
ID=77415797
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110528640.XA Pending CN113318468A (en) | 2021-05-14 | 2021-05-14 | Production system for removing VOC (volatile organic compounds) from polyether polyol |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113318468A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5470478A (en) * | 1993-06-21 | 1995-11-28 | Leva; Max | Apparatus and method for stripping and absorption of volatile materials |
| CN102985147A (en) * | 2009-09-29 | 2013-03-20 | 陶氏环球技术有限责任公司 | Single column stripping and drying process |
| US20170226240A1 (en) * | 2016-02-04 | 2017-08-10 | Chevron Phillips Chemical Company Lp | Inert Stripping of Volatile Organic Compounds from Polymer Melts |
| CN211912779U (en) * | 2019-12-10 | 2020-11-13 | 中国科学院上海有机化学研究所 | Device for removing VOC (volatile organic compounds) in ethylene or ethylene copolymer and reducing odor grade under micro-negative pressure |
| CN112142880A (en) * | 2020-10-14 | 2020-12-29 | 长华化学科技股份有限公司 | Continuous purification method of polymer polyol |
| CN112142882A (en) * | 2020-09-25 | 2020-12-29 | 天华化工机械及自动化研究设计院有限公司 | VOC device in polypropylene is taken off to vapour method |
-
2021
- 2021-05-14 CN CN202110528640.XA patent/CN113318468A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5470478A (en) * | 1993-06-21 | 1995-11-28 | Leva; Max | Apparatus and method for stripping and absorption of volatile materials |
| CN102985147A (en) * | 2009-09-29 | 2013-03-20 | 陶氏环球技术有限责任公司 | Single column stripping and drying process |
| US20170226240A1 (en) * | 2016-02-04 | 2017-08-10 | Chevron Phillips Chemical Company Lp | Inert Stripping of Volatile Organic Compounds from Polymer Melts |
| CN211912779U (en) * | 2019-12-10 | 2020-11-13 | 中国科学院上海有机化学研究所 | Device for removing VOC (volatile organic compounds) in ethylene or ethylene copolymer and reducing odor grade under micro-negative pressure |
| CN112142882A (en) * | 2020-09-25 | 2020-12-29 | 天华化工机械及自动化研究设计院有限公司 | VOC device in polypropylene is taken off to vapour method |
| CN112142880A (en) * | 2020-10-14 | 2020-12-29 | 长华化学科技股份有限公司 | Continuous purification method of polymer polyol |
Non-Patent Citations (1)
| Title |
|---|
| 张一安等编著: "《高效油气集输与处理技术》", 《华东理工大学出版社》, pages: 135 - 137 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102838096B (en) | Joint production method and production device of dilute nitric acid and concentrated nitric acid | |
| CN105600752B (en) | A kind of method of purification and its system for being used for hydrogen in biological fuel gas | |
| CN201058267Y (en) | Device for cleaning and reclaiming urea dust | |
| CN111847453B (en) | Device and process for preparing ultra-pure carbon monoxide | |
| CN106362548A (en) | Treating method of oxidized tail gas in process of manufacturing cyclohexanone with cyclohexane oxidation method | |
| CN102267868A (en) | Industrial production apparatus for trichloroethylene | |
| CN215505542U (en) | Production system capable of removing volatile organic compounds in polyether polyol | |
| CN113318468A (en) | Production system for removing VOC (volatile organic compounds) from polyether polyol | |
| CN112898120B (en) | Device and method for producing ethylene glycol | |
| CN106914097B (en) | Recovering SO-containing material 2 Device and method for HCl tail gas | |
| CN105061133B (en) | The recovery method of acetylene and retracting device during a kind of vinyl acetate production | |
| CN108862205B (en) | Hydrogen peroxide preparation device | |
| CN107778140A (en) | A kind of purification method of ethylene glycol sorption extraction deep dehydration removal of impurities | |
| CN216404259U (en) | System for continuously preparing acetophenone | |
| CN103772330B (en) | Method for recovery of furfural and acetic acid from furfural stripping steam condensate | |
| CN102442893B (en) | Separation method of aldehyde condensation products | |
| CN201567231U (en) | Hydrogen chloride desorption tower device for recycling polycrystalline silicon production tail gas | |
| CN212833552U (en) | Preparation device and control system of lauric acid monoglyceride | |
| CN103896747A (en) | Backpack type circulation production process device of high-concentration methylal | |
| CN211752593U (en) | EO takes off aldehyde refining plant in ethylene oxide production | |
| EP0354243B1 (en) | Process for concentrating and purifying alchohol | |
| CN210495821U (en) | Solvent recovery system in BP-3 drying section vacuum tail gas | |
| CN111228941A (en) | Tail gas separation device and method in process for electrochemically synthesizing adiponitrile from acrylonitrile | |
| CN111484408A (en) | Preparation device and method of lauric acid monoglyceride, control system and method | |
| CN219681713U (en) | Working solution moisture removal system in hydrogen peroxide production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210831 |
|
| RJ01 | Rejection of invention patent application after publication |