CN110759821A - Neopentyl glycol production raw material recovery system and recovery method thereof - Google Patents
Neopentyl glycol production raw material recovery system and recovery method thereof Download PDFInfo
- Publication number
- CN110759821A CN110759821A CN201911160027.6A CN201911160027A CN110759821A CN 110759821 A CN110759821 A CN 110759821A CN 201911160027 A CN201911160027 A CN 201911160027A CN 110759821 A CN110759821 A CN 110759821A
- Authority
- CN
- China
- Prior art keywords
- raw material
- gas
- condenser
- neopentyl glycol
- buffer tank
- 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
- 238000011084 recovery Methods 0.000 title claims abstract description 100
- 239000002994 raw material Substances 0.000 title claims abstract description 77
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 39
- SLCVBVWXLSEKPL-UHFFFAOYSA-N neopentyl glycol Chemical compound OCC(C)(C)CO SLCVBVWXLSEKPL-UHFFFAOYSA-N 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 17
- 239000007789 gas Substances 0.000 claims abstract description 185
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims abstract description 100
- GETQZCLCWQTVFV-UHFFFAOYSA-N trimethylamine Chemical compound CN(C)C GETQZCLCWQTVFV-UHFFFAOYSA-N 0.000 claims abstract description 62
- 238000004821 distillation Methods 0.000 claims abstract description 49
- 238000007906 compression Methods 0.000 claims abstract description 36
- 230000006835 compression Effects 0.000 claims abstract description 35
- 238000006243 chemical reaction Methods 0.000 claims abstract description 30
- 238000010992 reflux Methods 0.000 claims abstract description 26
- 238000009833 condensation Methods 0.000 claims abstract description 6
- 230000005494 condensation Effects 0.000 claims abstract description 6
- 239000007791 liquid phase Substances 0.000 claims description 68
- 239000012071 phase Substances 0.000 claims description 60
- 239000007788 liquid Substances 0.000 claims description 33
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 31
- 239000002912 waste gas Substances 0.000 claims description 27
- AMIMRNSIRUDHCM-UHFFFAOYSA-N Isopropylaldehyde Chemical compound CC(C)C=O AMIMRNSIRUDHCM-UHFFFAOYSA-N 0.000 claims description 22
- 238000011144 upstream manufacturing Methods 0.000 claims description 15
- 238000006482 condensation reaction Methods 0.000 claims description 11
- 239000012295 chemical reaction liquid Substances 0.000 claims description 5
- 238000004891 communication Methods 0.000 claims description 5
- 239000006227 byproduct Substances 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract description 24
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 abstract description 18
- 239000001569 carbon dioxide Substances 0.000 abstract description 9
- 229910002092 carbon dioxide Inorganic materials 0.000 abstract description 9
- 239000002699 waste material Substances 0.000 abstract description 4
- 230000000694 effects Effects 0.000 abstract 1
- 235000019256 formaldehyde Nutrition 0.000 description 31
- 238000009835 boiling Methods 0.000 description 22
- 150000001299 aldehydes Chemical class 0.000 description 11
- 239000007792 gaseous phase Substances 0.000 description 8
- 238000002844 melting Methods 0.000 description 8
- 230000008018 melting Effects 0.000 description 8
- 239000000463 material Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 230000001105 regulatory effect Effects 0.000 description 5
- 238000001816 cooling Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 239000003507 refrigerant Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 235000021323 fish oil Nutrition 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 125000003718 tetrahydrofuranyl group Chemical group 0.000 description 2
- SUTLBTHMXYSMSZ-UHFFFAOYSA-N 2-hydroxypentanal Chemical compound CCCC(O)C=O SUTLBTHMXYSMSZ-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/78—Separation; Purification; Stabilisation; Use of additives
- C07C45/81—Separation; Purification; Stabilisation; Use of additives by change in the physical state, e.g. crystallisation
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the field of neopentyl glycol production and manufacturing, and particularly discloses a neopentyl glycol production raw material recovery system and a neopentyl glycol production raw material recovery method. The method mainly solves the technical problems that in the prior art, the gas phase condensation effect of formaldehyde and trimethylamine separated from the top of a distillation tower is not ideal, so that valuable components which are as much as possible cannot be recycled, the raw material waste is serious, and the emission of tail gas is increased. The invention comprises the following steps: the distillation tower is an atmospheric distillation tower; the condenser is arranged at the top of the distillation tower; the reflux tank is arranged below the condenser; a liquefied gas compression system; and the gas phase channel is used for respectively communicating the condenser with the liquefied gas compression system and communicating the reflux tank with the liquefied gas compression system, compressing and liquefying components which cannot be condensed in the condenser by a physical compression method and sending the components back to the reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, the utilization rate of raw materials is improved, the load of a tail gas treatment device is reduced, and the emission of carbon dioxide and nitrogen oxides is reduced.
Description
Technical Field
The invention relates to the field of neopentyl glycol production and manufacturing, in particular to a neopentyl glycol production raw material recovery system and a recovery method thereof.
Background
At present, most of the neopentyl glycol production in the industry adopts a method of performing aldehyde condensation reaction on isobutyraldehyde and formaldehyde in an organic amine catalyst environment to generate hydroxypentanal, then recovering part of raw materials through an aldehyde recovery process, removing light components, hydrogenating to generate neopentyl glycol, and finally rectifying and purifying.
The existing aldehyde recovery technology is that a condensation reaction liquid is sent to an aldehyde recovery tower through a continuous pump for distillation, a light component evaporated from the top of the tower enters a tower top condenser in a gaseous state, the tower top condenser uses circulating water as a refrigerant, the gaseous light component is condensed into a liquid state in the condenser and is collected to a reflux tank, but due to the physical properties of certain components, only part of the components can be condensed into a liquid phase in the condenser, and part of the components cannot be condensed and are directly sent to a tail gas treatment device. The bottom of the aldehyde recovery tower is a purified substance and goes to a hydrogenation process.
Specifically, in the process of aldehyde recovery, the reaction solution after the condensation reaction is subjected to atmospheric distillation (note: there is also a scheme of distillation under pressure, but the steam consumption is large) in an aldehyde recovery tower to separate materials with lower boiling points, the materials with lower boiling points mainly comprise formaldehyde and isobutyraldehyde which are used as raw materials, trimethylamine which is used as a catalyst, a side reaction product methanol and the like, the materials are distilled out from the top of the tower in a gaseous state and go to a condenser at the top of the tower to be condensed, the condenser adopts circulating water as a refrigerant, the temperature of the circulating water is about 30 ℃, the boiling point of the formaldehyde is-19.4 ℃, the boiling point of the isobutyraldehyde is 64 ℃, the boiling point of the trimethylamine is 2.87 ℃, the boiling point of the methanol is 64.8 ℃ under the atmospheric pressure, and the temperature of the refrigerant is higher than the boiling points of the formaldehyde and the trimethylamine, so that the formaldehyde and.
As described above, in the process of recovering the aldehyde, which is a raw material for producing neopentyl glycol, in the prior art, only isobutyraldehyde and methanol can be condensed and recovered, formaldehyde and trimethylamine cannot be condensed into a liquid phase in the condenser, the mass of formaldehyde and trimethylamine in the gas flow accounts for about 20%, and the valuable materials are directly sent to a tail gas treatment device for treatment, so that not only is the raw material wasted, but also the emission of tail gas is increased. In view of the above problems in the prior art, the gas phase of formaldehyde and trimethylamine separated from the top of the distillation tower cannot be condensed into a liquid phase by a circulating water condenser, so that valuable components cannot be recovered and reused as much as possible, which causes serious waste of raw materials and increases the emission of tail gas, and therefore, the prior art needs to be improved.
Disclosure of Invention
One of the purposes of the invention is to provide a neopentyl glycol production raw material recovery system, so as to solve the technical problems that in the prior art, the gas phase of formaldehyde and trimethylamine separated from the top of a distillation tower cannot be condensed into a liquid phase by a circulating water condenser, so that valuable components as much as possible cannot be recovered for reuse, the waste of raw materials is serious, and the emission of tail gas is increased.
The invention also aims to provide a raw material recovery method based on a neopentyl glycol production raw material recovery system.
In order to achieve one of the purposes, the invention adopts the following technical scheme:
a neopentyl glycol raw material for production recovery system, wherein, includes:
a distillation tower 1, wherein the distillation tower 1 is an atmospheric distillation tower, and the distillation tower 1 is used for carrying out atmospheric distillation operation on reaction liquid in the distillation tower 1;
the condenser 2 is arranged at the outlet of the top of the distillation tower 1, and the condenser 2 is communicated with the distillation tower 1 through a communication pipeline;
the reflux tank 3 is arranged below the condenser 2, and the reflux tank 3 is communicated with the condenser 2 through a communicating pipeline to carry out primary raw material recovery;
a liquefied gas compression system;
the gas phase channel 4 is connected with the condenser 2, the reflux tank 3 and the liquefied gas compression system respectively;
the gas phase passage 4 communicates the condenser 2 with the liquefied gas compression system, and the gas phase passage 4 communicates the reflux drum 3 with the liquefied gas compression system.
By adopting the technical means, the neopentyl glycol production raw material recovery system is internally provided with the liquefied gas compression system, so that a low-boiling-point gas phase which is condensed by the condenser and is not liquefied enters the liquefied gas compression system through the gas phase channel, the gas phase sequentially passes through the first buffer tank, the liquefied gas compressor and the second buffer tank, the low-boiling-point gas phase is liquefied through physical compression to form a liquid phase, the components which cannot be condensed in the condenser are compressed and liquefied, then the components are cooled by the liquid phase cooler and enter the liquid phase recovery pipeline for secondary raw material recovery, and finally the components are sent back to the upstream reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, and the utilization rate of raw materials is improved; specifically, the recovery efficiency of the light components separated from the top of the aldehyde recovery tower is improved from about 79 percent to about 98 percent, the consumption of raw materials is reduced, and the yield of products is improved.
Meanwhile, the non-condensable gas accumulated and generated in the second buffer tank enters a non-condensable gas pipeline through the gas phase condenser and finally enters an external waste gas treatment system, and the non-condensable gas is treated by the external waste gas treatment system and then discharged up to the standard, so that the load of a tail gas treatment device is reduced, and the discharge of carbon dioxide and nitric oxide is reduced; in particular, emissions of about 2297.95 tons of carbon dioxide and 523.76 tons of nitrogen oxides (calculated as NO 2) per year are reduced.
According to one embodiment of the invention, the liquefied gas compression system comprises a first buffer tank 5, wherein the first buffer tank 5 is a liquefied gas compressor inlet buffer tank; a liquefied gas compressor 7; the second buffer tank 8, the second buffer tank 8 is an outlet buffer tank of a liquefied gas compressor; the first buffer tank 5, the liquefied gas compressor 7 and the second buffer tank 8 are communicated in sequence through communicating pipelines. Adopt above-mentioned technical means, the low boiling point gaseous phase that does not liquefy through the condenser condensation passes through gaseous phase passageway and gets into liquefied gas compression system, the gaseous phase passes through first buffer tank, liquefied gas compressor, the second buffer tank in proper order, the low boiling point gaseous phase is liquefied through physical compression and is formed the liquid phase, compress the liquefaction with this part of unable component of condensing in the condenser, then get into liquid phase recovery pipeline after liquid phase cooler cooling, carry out the second raw materials recovery, and finally send back upstream reaction system, the consumption of formaldehyde and trimethylamine has been reduced, the utilization ratio of raw and other materials has been improved. In addition, the compressor has the advantages of low investment cost, simple structure principle, simple operation and convenient maintenance.
According to one embodiment of the invention, wherein the first buffer tank 5 is provided with a blow line 6. By adopting the technical means, the vent line can lead the gas discharged by the condenser 2 and the reflux tank 3 into the tail gas treatment device under the fault state of the liquefied gas compressor 7, and ensure that the distillation tower 1, the condenser 2 and the reflux tank 3 work under normal operating pressure.
According to an embodiment of the present invention, wherein the neopentyl glycol production raw material recovery system further comprises: a liquid phase recovery pipeline 10, the liquid phase recovery pipeline 10 being in communication with the second buffer tank 8.
According to an embodiment of the invention, the liquid phase recovery pipeline 10 is externally communicated with a reaction device upstream of the reaction system, and the liquid phase recovery pipeline 10 adds a liquid formaldehyde and liquid trimethylamine mixture into the reaction device to continuously participate in the reaction.
According to an embodiment of the present invention, wherein the neopentyl glycol production raw material recovery system further comprises: a liquid phase cooler 9, wherein the liquid phase cooler 9 is arranged between the second buffer tank 8 and the liquid phase recovery pipeline 10. By adopting the technical means, the raw materials are cooled by the liquid-phase cooler 9 and then enter the liquid-phase recovery pipeline 10 to be recovered for the second time and finally sent back to the upstream reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, and the utilization rate of the raw materials is improved.
According to an embodiment of the present invention, the liquid phase recovery pipeline 10 is provided with a self-regulating valve. By adopting the technical means, the liquid phase recovery pipeline 10 is provided with an automatic regulating valve for controlling the liquid level of the second buffer tank 8 and keeping a certain liquid level, so that the air pressure in the second buffer tank 8 is prevented from being mixed with other systems.
According to an embodiment of the present invention, wherein the neopentyl glycol production raw material recovery system further comprises: a non-condensable gas pipeline 12, wherein the non-condensable gas pipeline 12 is communicated with the second buffer tank 8.
According to an embodiment of the present invention, the noncondensable gas pipe 12 is connected to an external exhaust gas treatment system, and the condensed exhaust gas is led to the exhaust gas treatment system for exhaust gas treatment. By adopting the technical means, the noncondensable gas pipeline 12 is connected with an external waste gas treatment system, and condensed waste gas is led to the waste gas treatment system for waste gas treatment, so that the load of a tail gas treatment device is reduced, and the emission of carbon dioxide and nitrogen oxides is reduced.
According to an embodiment of the present invention, wherein the neopentyl glycol production raw material recovery system further comprises: and the gas phase condenser 11 is arranged between the second buffer tank 8 and the non-condensable gas pipeline 12. By adopting the technical means, the gas phase condenser 11 is used for further condensing the gas phase, the cooled liquid phase cooler enters the liquid phase recovery pipeline for secondary raw material recovery, the liquid formaldehyde and the liquid trimethylamine which are physically pressurized and liquefied by the liquefied gas compressor are prevented from being excessively gasified again, and only the noncondensable gas goes to the subsequent external waste gas treatment system.
In order to achieve the second purpose, the invention adopts the following technical scheme:
a raw material recovery method based on a neopentyl glycol production raw material recovery system comprises the following steps:
distilling, and carrying out atmospheric distillation operation on the crude hydroxytetravaleraldehyde liquid obtained after the condensation reaction in a distillation tower 1;
condensing, wherein the gas phase enters a condenser 2 from the top of the distillation tower 1 for condensation;
refluxing, condensing unreacted isobutyraldehyde and a byproduct methanol in the condensation reaction in a condenser 2, liquefying, and then entering a reflux tank 3 for primary raw material recovery;
compressing liquefied gas, namely condensing non-liquefied low-boiling-point gas phase by a condenser 2, allowing the non-liquefied low-boiling-point gas phase to enter a liquefied gas compression system through a gas phase channel 4, allowing the gas phase to sequentially pass through a first buffer tank 5, a liquefied gas compressor 7 and a second buffer tank 8, and liquefying the low-boiling-point gas phase to form a liquid phase;
and (4) recovering, wherein the liquid phase is cooled by a liquid phase cooler 9 and then enters a liquid phase recovery pipeline 10 for secondary raw material recovery, and the recovered raw materials are returned to a reaction system at the upstream of the system to continue to participate in the reaction.
According to an embodiment of the present invention, further, after the gas phase passes through the second buffer tank 8, the non-condensable gas accumulated in the second buffer tank 8 passes through the gas phase condenser 11 and enters the non-condensable gas pipeline 12, and finally enters the external waste gas treatment system.
The properties of the substances involved in the present invention:
① Formaldehyde CAS #: 50-00-0, molecular formula CH2O, molecular weight 30.03, colorless transparent liquid, pungent and suffocating odor, melting point-92 deg.C, liquid relative density 0.82, boiling point-19.4 deg.C.
② iso-butyraldehyde CAS #: 78-84-2, molecular formula C4H8O, molecular weight 72.11, colorless transparent liquid, strong pungent smell, melting point-65 deg.C, liquid relative density 0.79, boiling point 64 deg.C.
③ methanol CAS #: 67-56-1, molecular formula CH4O, molecular weight 32.04, colorless clear liquid, pungent smell, melting point-97.8 deg.C, liquid relative density 0.79, boiling point 64.8 deg.C.
④ CAS # 75-50-3 of trimethylamine, molecular formula (CH3)3-N, molecular weight 59.11, colorless, gas with fish oil odor, melting point-117.1 deg.C, liquid relative density 0.662, boiling point 2.87 deg.C.
Has the advantages that:
compared with the prior art, the formaldehyde and trimethylamine gas phase separated from the tower top by the atmospheric distillation of the reaction liquid after the condensation reaction can not be condensed into the liquid phase by the circulating water condenser, part of the gas phase from the distillation tower is directly connected to the tail gas treatment device, the treated gas is finally discharged into the atmosphere, valuable components which are as much as possible can not be recovered and reused, the raw material waste is serious, and the technical problem of tail gas discharge is also increased. Then the cooled raw materials enter a liquid phase recovery pipeline after being cooled by a liquid phase cooler, are subjected to secondary raw material recovery and are finally sent back to an upstream reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, and the utilization rate of the raw materials is improved; specifically, the recovery efficiency of the light components separated from the top of the aldehyde recovery tower is improved from about 79 percent to about 98 percent, the consumption of raw materials is reduced, and the yield of products is improved.
Meanwhile, the non-condensable gas accumulated and generated in the second buffer tank enters a non-condensable gas pipeline through the gas phase condenser and finally enters an external waste gas treatment system, and the non-condensable gas is treated by the external waste gas treatment system and then discharged up to the standard, so that the load of a tail gas treatment device is reduced, and the discharge of carbon dioxide and nitric oxide is reduced; in particular, emissions of about 2297.95 tons of carbon dioxide and 523.76 tons of nitrogen oxides (calculated as NO 2) per year are reduced.
Drawings
The invention is further illustrated with reference to the following figures and examples.
FIG. 1 is a schematic structural diagram of a neopentyl glycol production raw material recovery system according to an embodiment of the present invention.
In the drawings:
1. distillation tower 2, condenser 3 and reflux tank
4. Gas phase channel 5, first buffer tank 6 and emptying pipeline
7. Liquefied gas compressor 8, second buffer tank 9 and liquid phase cooler
10. Liquid phase recovery pipeline 11, gas phase condenser 12 and non-condensable gas pipeline
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clear and fully described, embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are illustrative of some, but not all embodiments of the invention, and are intended to be exemplary only and not limiting of the invention, and that all other embodiments obtained by those skilled in the art without making any inventive change thereto will fall within the scope of the invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "inner", "outer", "top", "bottom", "side", "vertical", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "a," "an," "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
For the purposes of simplicity and explanation, the principles of the embodiments are described by referring mainly to examples. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. It will be apparent, however, to one skilled in the art that the embodiments may be practiced without these specific details. In some instances, well-known methods and structures have not been described in detail so as not to unnecessarily obscure the embodiments. In addition, all embodiments may be used in combination with each other.
The first embodiment is as follows:
as shown in fig. 1, a neopentyl glycol production raw material recovery system, comprising:
a distillation tower 1, wherein the distillation tower 1 is an atmospheric distillation tower, and the distillation tower 1 is used for carrying out atmospheric distillation operation on reaction liquid in the distillation tower 1; the condenser 2 is arranged at the top of the distillation tower 1, and the condenser 2 is communicated with the distillation tower 1 through a communication pipeline; the reflux tank 3 is arranged below the condenser 2, and the reflux tank 3 is communicated with the condenser 2 through a communicating pipeline; a liquefied gas compression system; the gas phase channel 4 is connected with the condenser 2, the reflux tank 3 and the liquefied gas compression system respectively; the gas phase passage 4 communicates the condenser 2 with the liquefied gas compression system, and the gas phase passage 4 communicates the reflux drum 3 with the liquefied gas compression system.
Compared with the prior art, the formaldehyde and trimethylamine gas phase separated from the tower top by atmospheric distillation of the reaction solution after the condensation reaction can not be condensed into a liquid phase by a circulating water condenser, and can not be recovered and sent back to an upstream reaction system for reuse, the gas phase (specifically, the formaldehyde and the trimethylamine) from the distillation tower is directly connected to a tail gas treatment device, the treated gas is finally discharged into the atmosphere, and the valuable materials are directly sent to the tail gas treatment device for treatment, so that the raw materials are wasted, and the emission of the tail gas is increased. The neopentyl glycol production raw material recovery system is provided with the liquefied gas compression system, so that a low-boiling-point gas phase which is condensed by a condenser and not liquefied enters the liquefied gas compression system through a gas phase channel, the gas phase sequentially passes through the first buffer tank, the liquefied gas compressor and the second buffer tank, the low-boiling-point gas phase is liquefied through physical compression to form a liquid phase, components which cannot be condensed in the condenser are compressed and liquefied, then the components are cooled by the liquid phase cooler and enter a liquid phase recovery pipeline for secondary raw material recovery, and finally the components are sent back to an upstream reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, and the utilization rate of raw materials is improved; specifically, the recovery efficiency of the light components separated from the top of the aldehyde recovery tower is improved from about 79 percent to about 98 percent, the consumption of raw materials is reduced, and the yield of products is improved.
Meanwhile, the non-condensable gas accumulated and generated in the second buffer tank enters a non-condensable gas pipeline through the gas phase condenser and finally enters an external waste gas treatment system, and the non-condensable gas is treated by the external waste gas treatment system and then discharged up to the standard, so that the load of a tail gas treatment device is reduced, and the discharge of carbon dioxide and nitric oxide is reduced; in particular, emissions of about 2297.95 tons of carbon dioxide and 523.76 tons of nitrogen oxides (calculated as NO 2) per year are reduced.
The liquefied gas compression system includes: the first buffer tank 5 is a liquefied gas compressor inlet buffer tank; a liquefied gas compressor 7; the second buffer tank 8, the second buffer tank 8 is an outlet buffer tank of a liquefied gas compressor; the first buffer tank 5, the liquefied gas compressor 7 and the second buffer tank 8 are communicated in sequence through communicating pipelines. The liquefied gas compression system is used for liquefying low-boiling-point gas through a physical compression process. The components which cannot be condensed in the condenser are compressed and liquefied by a physical compression method and are returned to an upstream reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, and the utilization rate of raw materials is improved.
The liquefied gas compressor 7 is fixed in structure and mainly comprises a compressor main machine, a motor, a coupling, a flywheel, a pipeline system, a cooling system, electrical equipment and auxiliary equipment. The liquefied gas compressor 7 adopted in the embodiment of the invention has the following attribute characteristics: the flow rate is controlled to be 1.5m3/min, and the air inlet pressure is normal pressure; the exhaust pressure was 1.7MPaG and the power was 15 kW.
Among the liquefied gas compression system, the low boiling point gaseous phase that does not liquefy through the condenser condensation passes through gaseous phase passageway and gets into liquefied gas compression system, the gaseous phase passes through first buffer tank in proper order, the liquefied gas compressor, the second buffer tank, the low boiling point gaseous phase is liquefied through physical compression and is formed the liquid phase, compress the liquefaction with this part of unable component of condensing in the condenser, then go into liquid phase recovery pipeline after the liquid phase cooler cooling, carry out the second time raw materials and retrieve, and finally send back upstream reaction system, the consumption of formaldehyde and trimethylamine has been reduced, the utilization ratio of raw and other materials has been improved. In addition, the compressor has the advantages of low investment cost, simple structure principle, simple operation and convenient maintenance.
The first buffer tank 5 is provided with a blow-down line 6. By adopting the technical means, the vent line can lead the gas discharged by the condenser 2 and the reflux tank 3 into the tail gas treatment device under the fault state of the liquefied gas compressor 7, and ensure that the distillation tower 1, the condenser 2 and the reflux tank 3 work under normal operating pressure.
A liquid phase recovery pipeline 10, the liquid phase recovery pipeline 10 being in communication with the second buffer tank 8. The outside of the liquid phase recovery pipeline 10 is communicated with a reaction device at the upstream of the reaction system, and the liquid phase recovery pipeline 10 adds the mixture of the liquid formaldehyde and the liquid trimethylamine into the upstream reaction device to continuously participate in the reaction. The liquid phase recovery pipeline 10 is provided with an automatic regulating valve. By adopting the technical means, the liquid phase recovery pipeline 10 is provided with an automatic regulating valve for controlling the liquid level of the second buffer tank 8 and keeping a certain liquid level, so that the air pressure in the second buffer tank 8 is prevented from being mixed with other systems.
A liquid phase cooler 9, wherein the liquid phase cooler 9 is arranged between the second buffer tank 8 and the liquid phase recovery pipeline 10. By adopting the technical means, the raw materials are cooled by the liquid-phase cooler 9 and then enter the liquid-phase recovery pipeline 10 to be recovered for the second time and finally sent back to the upstream reaction system, so that the consumption of formaldehyde and trimethylamine is reduced, and the utilization rate of the raw materials is improved.
A non-condensable gas pipeline 12, wherein the non-condensable gas pipeline 12 is communicated with the second buffer tank 8. The noncondensable gas pipeline 12 is connected with an external waste gas treatment system, and condensed waste gas is led to the waste gas treatment system for waste gas treatment. An automatic regulating valve is arranged on the non-condensable gas pipeline 12; the automatic regulating valve on the noncondensable gas pipeline 12 controls the pressure of the second buffer tank 8, maintains about 1.4MPaG (under the pressure, the boiling point of formaldehyde is 67 ℃ and the boiling point of trimethylamine is 103 ℃), increases the boiling points of formaldehyde and trimethylamine, and maintains the liquid state of the formaldehyde and the trimethylamine. By adopting the technical means, the noncondensable gas pipeline 12 is connected with an external waste gas treatment system, and condensed waste gas is led to the waste gas treatment system for waste gas treatment, so that the load of a tail gas treatment device is reduced, and the emission of carbon dioxide and nitrogen oxides is reduced.
And the gas phase condenser 11 is arranged between the second buffer tank 8 and the non-condensable gas pipeline 12. By adopting the technical means, the gas phase condenser 11 is used for further condensing the gas phase, the cooled liquid phase cooler enters the liquid phase recovery pipeline for secondary raw material recovery, the liquid formaldehyde and the liquid trimethylamine which are physically pressurized and liquefied by the liquefied gas compressor are prevented from being excessively gasified again, and only the noncondensable gas goes to the subsequent external waste gas treatment system.
The properties of the substances involved in the present invention:
① Formaldehyde CAS #: 50-00-0, molecular formula CH2O, molecular weight 30.03, colorless transparent liquid, pungent and suffocating odor, melting point-92 deg.C, liquid relative density 0.82, boiling point-19.4 deg.C.
② iso-butyraldehyde CAS #: 78-84-2, molecular formula C4H8O, molecular weight 72.11, colorless transparent liquid, strong pungent smell, melting point-65 deg.C, liquid relative density 0.79, boiling point 64 deg.C.
③ methanol CAS #: 67-56-1, molecular formula CH4O, molecular weight 32.04, colorless clear liquid, pungent smell, melting point-97.8 deg.C, liquid relative density 0.79, boiling point 64.8 deg.C.
④ CAS # 75-50-3 of trimethylamine, molecular formula (CH3)3-N, molecular weight 59.11, colorless, gas with fish oil odor, melting point-117.1 deg.C, liquid relative density 0.662, boiling point 2.87 deg.C.
A raw material recovery method based on a neopentyl glycol production raw material recovery system comprises the following steps:
distilling, and carrying out atmospheric distillation operation on the crude hydroxytetravaleraldehyde liquid obtained after the condensation reaction in a distillation tower 1;
condensing, wherein the gas phase enters a condenser 2 from the top of the distillation tower 1 for condensation;
refluxing, condensing unreacted isobutyraldehyde and a byproduct methanol in the condensation reaction in a condenser 2, liquefying, and then entering a reflux tank 3 for primary raw material recovery;
compressing liquefied gas, namely condensing non-liquefied low-boiling-point gas phase by a condenser 2, allowing the non-liquefied low-boiling-point gas phase to enter a liquefied gas compression system through a gas phase channel 4, allowing the gas phase to sequentially pass through a first buffer tank 5, a liquefied gas compressor 7 and a second buffer tank 8, and liquefying the low-boiling-point gas phase to form a liquid phase;
and (4) recovering, wherein the liquid phase is cooled by a liquid phase cooler 9 and then enters a liquid phase recovery pipeline 10 for secondary raw material recovery, and the recovered raw materials are returned to the reaction system at the early stage of the system to continue to participate in the reaction.
According to an embodiment of the present invention, further, after the gas phase passes through the second buffer tank 8, the non-condensable gas accumulated in the second buffer tank 8 passes through the gas phase condenser 11 and enters the non-condensable gas pipeline 12, and finally enters the external waste gas treatment system.
Although the illustrative embodiments of the present invention have been described above to enable those skilled in the art to understand the present invention, the present invention is not limited to the scope of the embodiments, and it is to be understood that all the inventions utilizing the inventive concept can be protected by those skilled in the art as long as various changes are within the spirit and scope of the present invention as defined and defined in the appended claims.
Claims (12)
1. A neopentyl glycol raw material for production recovery system, wherein, includes:
the distillation tower (1), the distillation tower (1) is an atmospheric distillation tower, and the distillation tower (1) is used for carrying out atmospheric distillation operation on the reaction liquid in the distillation tower (1);
the condenser (2) is arranged at an outlet at the top of the distillation tower (1), and the condenser (2) is communicated with the distillation tower (1) through a communicating pipeline;
the reflux tank (3) is arranged below the condenser (2), and the reflux tank (3) is communicated with the condenser (2) through a communicating pipeline;
a liquefied gas compression system;
the gas phase channel (4), the gas phase channel (4) is respectively connected with the condenser (2), the reflux tank (3) and the liquefied gas compression system;
the gas phase passage (4) communicates the condenser (2) with the liquefied gas compression system, and the gas phase passage (4) communicates the reflux drum (3) with the liquefied gas compression system.
2. A neopentyl glycol production feedstock recovery system as claimed in claim 1, wherein the liquefied gas compression system comprises:
the first buffer tank (5), the first buffer tank (5) is an inlet buffer tank of a liquefied gas compressor;
a liquefied gas compressor (7);
the second buffer tank (8), the second buffer tank (8) is an outlet buffer tank of a liquefied gas compressor;
the first buffer tank (5), the liquefied gas compressor (7) and the second buffer tank (8) are communicated in sequence through communicating pipelines.
3. A neopentyl glycol production raw material recovery system according to claim 2, wherein said first buffer tank (5) is provided with a vent line (6).
4. A neopentyl glycol production raw material recovery system as claimed in claim 2, wherein said neopentyl glycol production raw material recovery system further comprises:
a liquid phase recovery conduit (10), the liquid phase recovery conduit (10) being in communication with the second buffer tank (8).
5. A neopentyl glycol production raw material recovery system as claimed in claim 4, wherein the liquid phase recovery pipeline (10) is externally communicated with a reaction device at the upstream of the reaction system, and the liquid phase recovery pipeline (10) adds the liquid formaldehyde and liquid trimethylamine mixture into the reaction device to continue to participate in the reaction.
6. The neopentyl glycol production raw material recovery system as claimed in claim 4, wherein said neopentyl glycol production raw material recovery system further comprises:
a liquid phase cooler (9), the liquid phase cooler (9) being disposed between the second buffer tank (8) and the liquid phase recovery pipeline (10).
7. A neopentyl glycol production raw material recovery system as claimed in claim 4, wherein said liquid phase recovery pipeline (10) is provided with a self-regulating valve.
8. A neopentyl glycol production raw material recovery system as claimed in claim 2, wherein said neopentyl glycol production raw material recovery system further comprises:
a non-condensable gas pipeline (12), wherein the non-condensable gas pipeline (12) is communicated with the second buffer tank (8).
9. A neopentyl glycol production raw material recovery system according to claim 8, wherein said non-condensable gas duct (12) is connected to an external waste gas treatment system, and condensed waste gas is led to said waste gas treatment system for waste gas treatment.
10. The neopentyl glycol production raw material recovery system as claimed in claim 8, wherein said neopentyl glycol production raw material recovery system further comprises:
a gas phase condenser (11), the gas phase condenser (11) is arranged between the second buffer tank (8) and the non-condensable gas pipeline (12).
11. A raw material recovery method based on a neopentyl glycol production raw material recovery system comprises the following steps:
distilling, and carrying out atmospheric distillation operation on the crude hydroxytetravaleraldehyde liquid obtained after the condensation reaction in a distillation tower (1);
condensing, wherein a gas phase enters a condenser (2) from the top of the distillation tower (1) for condensation;
refluxing, wherein after unreacted isobutyraldehyde and a byproduct methanol in the condensation reaction are condensed in a condenser (2), the condensed isobutyraldehyde and the byproduct methanol are liquefied and enter a reflux tank (3) for primary raw material recovery;
the method comprises the following steps of (1) compressing liquefied gas, wherein a low-boiling-point gas phase which is not liquefied is condensed by a condenser (2) and enters a liquefied gas compression system through a gas phase channel (4), the gas phase sequentially passes through a first buffer tank (5), a liquefied gas compressor (7) and a second buffer tank (8), and the low-boiling-point gas phase is liquefied to form a liquid phase;
and (3) recovering, wherein the liquid phase is cooled by a liquid phase cooler (9) and then enters a liquid phase recovery pipeline (10) for secondary raw material recovery, and the recovered raw materials are returned to a reaction system at the upstream of the system to continue to participate in the reaction.
12. A raw material recovery method based on a neopentyl glycol production raw material recovery system as claimed in claim 11, wherein further, after the gas phase passes through the second buffer tank (8), the non-condensable gas accumulated in the second buffer tank (8) passes through the gas phase condenser (11) and enters the non-condensable gas pipeline (12) and finally enters the external waste gas treatment system.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201911160027.6A CN110759821A (en) | 2019-11-23 | 2019-11-23 | Neopentyl glycol production raw material recovery system and recovery method thereof |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN201911160027.6A CN110759821A (en) | 2019-11-23 | 2019-11-23 | Neopentyl glycol production raw material recovery system and recovery method thereof |
Publications (1)
Publication Number | Publication Date |
---|---|
CN110759821A true CN110759821A (en) | 2020-02-07 |
Family
ID=69339015
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201911160027.6A Pending CN110759821A (en) | 2019-11-23 | 2019-11-23 | Neopentyl glycol production raw material recovery system and recovery method thereof |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN110759821A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113952895A (en) * | 2021-11-01 | 2022-01-21 | 聊城市鲁西化工工程设计有限责任公司 | Continuous catalytic hydrogenation system and process for hydroxypivalaldehyde |
CN114165666A (en) * | 2021-11-10 | 2022-03-11 | 黄山锦峰实业有限公司 | Novel methanol rectification recovery process |
Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB833666A (en) * | 1955-06-23 | 1960-04-27 | Celanese Corp | Aldehyde condensation reactions |
JPS6118741A (en) * | 1984-07-06 | 1986-01-27 | Mitsubishi Gas Chem Co Inc | Preparation of high-purity hydroxypivalic aldehyde |
KR19980028461A (en) * | 1996-10-22 | 1998-07-15 | 성재갑 | How to prepare neopentyl glycol |
CN1189530A (en) * | 1998-01-21 | 1998-08-05 | 刘鸿逵 | Gasifying agent and prodn. method of L. P. G. raffinate |
CN1671640A (en) * | 2002-07-26 | 2005-09-21 | 巴斯福股份公司 | Method for increasing yield in the production of polyvalent alcohols by splitting by-products containing acetal |
WO2013026758A1 (en) * | 2011-08-23 | 2013-02-28 | Basf Se | Process for preparing neopentyl glycol |
CN103130611A (en) * | 2011-11-23 | 2013-06-05 | 山东华鲁恒升化工股份有限公司 | Neopentyl glycol condensation hydrogenation production process and device thereof |
CN204656288U (en) * | 2015-05-26 | 2015-09-23 | 南京都乐制冷设备有限公司 | The condensation of wood-based plate manufacturing adds absorption type formaldehyde retracting device |
CN204723984U (en) * | 2015-05-19 | 2015-10-28 | 南京都乐制冷设备有限公司 | The absorption type formaldehyde retracting device that industry of artificial boards is resolved with normal pressure |
CN105783421A (en) * | 2016-04-07 | 2016-07-20 | 成都赛普瑞兴科技有限公司 | Natural gas light hydrocarbon recovery method and device |
CN106800498A (en) * | 2015-11-25 | 2017-06-06 | 衡阳屹顺化工有限公司 | A kind of process units of neopentyl glycol |
CN107189808A (en) * | 2017-07-07 | 2017-09-22 | 宁夏宝塔石化科技实业发展有限公司 | A kind of petroleum fractionating column overhead non-condensable hydrocarbon gas compression recovery process |
CN107746040A (en) * | 2017-10-17 | 2018-03-02 | 山东新龙科技股份有限公司 | A kind of Processes and apparatus that hydrogen chloride is refined using the by-product gas for producing trichloro ethylene |
CN108380029A (en) * | 2018-04-20 | 2018-08-10 | 湖北泰盛化工有限公司 | A kind of alkyl esterification method glyphosate solvent recovering system and technique |
CN108409532A (en) * | 2018-04-20 | 2018-08-17 | 湖北泰盛化工有限公司 | A kind of alkyl esterification method production glyphosate solvent recovering system and technique based on B-grade condensation |
CN108489133A (en) * | 2018-03-13 | 2018-09-04 | 中国科学院理化技术研究所 | Multi-stage compression mixed working medium refrigerating/liquefying system |
CN110002982A (en) * | 2013-01-31 | 2019-07-12 | 伊斯曼化学公司 | The method for preparing polyalcohol |
-
2019
- 2019-11-23 CN CN201911160027.6A patent/CN110759821A/en active Pending
Patent Citations (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB833666A (en) * | 1955-06-23 | 1960-04-27 | Celanese Corp | Aldehyde condensation reactions |
JPS6118741A (en) * | 1984-07-06 | 1986-01-27 | Mitsubishi Gas Chem Co Inc | Preparation of high-purity hydroxypivalic aldehyde |
KR19980028461A (en) * | 1996-10-22 | 1998-07-15 | 성재갑 | How to prepare neopentyl glycol |
CN1189530A (en) * | 1998-01-21 | 1998-08-05 | 刘鸿逵 | Gasifying agent and prodn. method of L. P. G. raffinate |
CN1671640A (en) * | 2002-07-26 | 2005-09-21 | 巴斯福股份公司 | Method for increasing yield in the production of polyvalent alcohols by splitting by-products containing acetal |
WO2013026758A1 (en) * | 2011-08-23 | 2013-02-28 | Basf Se | Process for preparing neopentyl glycol |
CN103130611A (en) * | 2011-11-23 | 2013-06-05 | 山东华鲁恒升化工股份有限公司 | Neopentyl glycol condensation hydrogenation production process and device thereof |
CN110002982A (en) * | 2013-01-31 | 2019-07-12 | 伊斯曼化学公司 | The method for preparing polyalcohol |
CN204723984U (en) * | 2015-05-19 | 2015-10-28 | 南京都乐制冷设备有限公司 | The absorption type formaldehyde retracting device that industry of artificial boards is resolved with normal pressure |
CN204656288U (en) * | 2015-05-26 | 2015-09-23 | 南京都乐制冷设备有限公司 | The condensation of wood-based plate manufacturing adds absorption type formaldehyde retracting device |
CN106800498A (en) * | 2015-11-25 | 2017-06-06 | 衡阳屹顺化工有限公司 | A kind of process units of neopentyl glycol |
CN105783421A (en) * | 2016-04-07 | 2016-07-20 | 成都赛普瑞兴科技有限公司 | Natural gas light hydrocarbon recovery method and device |
CN107189808A (en) * | 2017-07-07 | 2017-09-22 | 宁夏宝塔石化科技实业发展有限公司 | A kind of petroleum fractionating column overhead non-condensable hydrocarbon gas compression recovery process |
CN107746040A (en) * | 2017-10-17 | 2018-03-02 | 山东新龙科技股份有限公司 | A kind of Processes and apparatus that hydrogen chloride is refined using the by-product gas for producing trichloro ethylene |
CN108489133A (en) * | 2018-03-13 | 2018-09-04 | 中国科学院理化技术研究所 | Multi-stage compression mixed working medium refrigerating/liquefying system |
CN108380029A (en) * | 2018-04-20 | 2018-08-10 | 湖北泰盛化工有限公司 | A kind of alkyl esterification method glyphosate solvent recovering system and technique |
CN108409532A (en) * | 2018-04-20 | 2018-08-17 | 湖北泰盛化工有限公司 | A kind of alkyl esterification method production glyphosate solvent recovering system and technique based on B-grade condensation |
Non-Patent Citations (3)
Title |
---|
刘佳彬: "浅谈甲醛及多聚甲醛的生产技术", 化工管理, pages 167 - 168 * |
国营五一0七厂等编: "小型制氧机操作与故障处理", 31 January 1980, 北京:化学工业出版社, pages: 15 - 18 * |
沈光球等编: "现代化学基础", 30 September 1999, 北京:清华大学出版社, pages: 5 - 7 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113952895A (en) * | 2021-11-01 | 2022-01-21 | 聊城市鲁西化工工程设计有限责任公司 | Continuous catalytic hydrogenation system and process for hydroxypivalaldehyde |
CN114165666A (en) * | 2021-11-10 | 2022-03-11 | 黄山锦峰实业有限公司 | Novel methanol rectification recovery process |
CN114165666B (en) * | 2021-11-10 | 2023-10-20 | 黄山锦峰实业有限公司 | Methanol rectification recovery process |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN113045372B (en) | Production process and device for preparing ethylene by ethanol dehydration | |
CN104016317A (en) | Method and device for preparing high-concentration dilute nitric acid | |
CN110759821A (en) | Neopentyl glycol production raw material recovery system and recovery method thereof | |
CN103003316B (en) | Expand for the ethene of cryogenic cooling in polyethylene exhaust gas recovery | |
CN110256202B (en) | Four-tower four-effect crude methanol refining process method | |
CN111592446A (en) | Rectification system and process for preparing ethylene glycol by dimethyl oxalate hydrogenation | |
CN112745208B (en) | Cyclohexanone recovery and separation process and system | |
CN101244970A (en) | Apparatus and technique for producing ethylene with ethyl alcohol | |
CN102267868A (en) | Industrial production apparatus for trichloroethylene | |
CN211035754U (en) | Neopentyl glycol raw materials for production recovery system | |
CN103759500A (en) | Method and device for manufacturing high purity nitrogen in low energy consumption mode | |
CN209702668U (en) | A kind of gas recovery system for oil | |
CN209771738U (en) | Liquid nitrogen low-temperature condensation VOC recovery processing device | |
CN216378008U (en) | System for producing low-residual alcohol monoalkyl fatty tertiary amine | |
CN214780781U (en) | System for utilize alcohol tail gas to retrieve alcohol and high-purity carbon dioxide as raw materials | |
CN215138328U (en) | Tail gas recovery device of methyl ethyl ketone rectifying device | |
CN212199062U (en) | Propylene recovery equipment | |
CN213590141U (en) | Chlor-alkali tail gas hydrogen extraction device | |
CN112409181A (en) | Dimethyl oxalate rectifying device for coal chemical industry | |
CN108046989B (en) | Device and method for purifying bioethanol | |
CN210409570U (en) | Tail gas recovery processing device in cyclohexanone rectification process | |
CN111530112A (en) | Purification device of carbon disulfide crude | |
CN110715506A (en) | Compression precooling device for oxygen production and working method thereof | |
CN219409637U (en) | Natural gas purification system and oilfield gas lift system | |
CN213147124U (en) | Empty surplus cold utilization system that divides |
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 |