CN106397089B - Method and system for recovering and purifying hexane solvent in ethylene propylene rubber production - Google Patents
Method and system for recovering and purifying hexane solvent in ethylene propylene rubber production Download PDFInfo
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- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 title claims abstract description 123
- 239000002904 solvent Substances 0.000 title claims abstract description 37
- 238000000034 method Methods 0.000 title claims abstract description 35
- 229920000181 Ethylene propylene rubber Polymers 0.000 title claims abstract description 28
- 238000010092 rubber production Methods 0.000 title claims abstract description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 54
- 239000000178 monomer Substances 0.000 claims abstract description 23
- 238000000926 separation method Methods 0.000 claims abstract description 23
- 150000001993 dienes Chemical class 0.000 claims abstract description 18
- 238000003860 storage Methods 0.000 claims abstract description 15
- 239000012071 phase Substances 0.000 claims abstract description 14
- 238000000746 purification Methods 0.000 claims abstract description 10
- 239000002699 waste material Substances 0.000 claims abstract description 10
- 239000007788 liquid Substances 0.000 claims abstract description 9
- 239000012074 organic phase Substances 0.000 claims abstract description 6
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 238000011084 recovery Methods 0.000 claims description 42
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 238000000605 extraction Methods 0.000 claims description 9
- 238000007664 blowing Methods 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 5
- 238000009833 condensation Methods 0.000 claims description 4
- 230000005494 condensation Effects 0.000 claims description 4
- 239000007791 liquid phase Substances 0.000 claims description 4
- 238000010992 reflux Methods 0.000 claims description 4
- 229920000642 polymer Polymers 0.000 claims description 3
- 238000004064 recycling Methods 0.000 claims description 2
- 239000008346 aqueous phase Substances 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 7
- 230000001105 regulatory effect Effects 0.000 abstract 1
- OJOWICOBYCXEKR-KRXBUXKQSA-N (5e)-5-ethylidenebicyclo[2.2.1]hept-2-ene Chemical compound C1C2C(=C/C)/CC1C=C2 OJOWICOBYCXEKR-KRXBUXKQSA-N 0.000 description 17
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 229920002943 EPDM rubber Polymers 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 5
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 5
- 229910052794 bromium Inorganic materials 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000006116 polymerization reaction Methods 0.000 description 4
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 239000005977 Ethylene Substances 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- 238000009776 industrial production Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 3
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 3
- 238000004073 vulcanization Methods 0.000 description 3
- HECLRDQVFMWTQS-RGOKHQFPSA-N 1755-01-7 Chemical compound C1[C@H]2[C@@H]3CC=C[C@@H]3[C@@H]1C=C2 HECLRDQVFMWTQS-RGOKHQFPSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000003197 catalytic effect Effects 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- 239000012968 metallocene catalyst Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 239000004636 vulcanized rubber Substances 0.000 description 2
- PRBHEGAFLDMLAL-GQCTYLIASA-N (4e)-hexa-1,4-diene Chemical compound C\C=C\CC=C PRBHEGAFLDMLAL-GQCTYLIASA-N 0.000 description 1
- RYPKRALMXUUNKS-UHFFFAOYSA-N 2-Hexene Natural products CCCC=CC RYPKRALMXUUNKS-UHFFFAOYSA-N 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- -1 ethylene, propylene Chemical group 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- DPUXQWOMYBMHRN-UHFFFAOYSA-N hexa-2,3-diene Chemical compound CCC=C=CC DPUXQWOMYBMHRN-UHFFFAOYSA-N 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000002407 reforming Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229930195735 unsaturated hydrocarbon Natural products 0.000 description 1
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- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
The invention discloses a method and a system for recovering and purifying a hexane solvent in ethylene propylene rubber production, and particularly relates to a method and a system for recovering and purifying a hexane solvent, wherein the recovered solvent is introduced into a rectifying tower, the rectifying temperature is controlled by regulating the flow of desalted water and the flow of steam controlled by a desalted water cooler to obtain hexane steam at the top of the tower, the hexane steam is introduced into a first condenser and is introduced into a storage tank after being condensed and liquefied to obtain purified hexane; the non-liquefied impurities are condensed and liquefied by a second condenser and then are recovered as waste liquid; and (3) after oil-water separation is carried out on the side line component of the rectifying tower, the water phase is circulated back to the lower part of the rectifying tower, and the organic phase serving as pre-purified diene is introduced into a subsequent third monomer purification unit to obtain the purified diene. By the method, the consumption of desalted water and steam is obviously reduced, the temperature point is more reasonably controlled, the separation effect of the rectifying tower is obviously improved, the content of the side stream component ENB of the rectifying tower for purifying hexane is reduced, the ENB loss is reduced to a large extent, and no peculiar smell is generated on site.
Description
Technical Field
the method relates to the field of recovery and purification of a solvent and third monomer diene in the production of ethylene propylene rubber
Background
The ethylene-propylene rubber is a copolymer synthesized by taking ethylene and propylene as basic monomers. The rubber molecular chains are different in monomer unit composition and comprise ethylene propylene rubber and ethylene propylene diene monomer rubber: the former is a copolymer of ethylene and propylene; the latter is a copolymer of ethylene, propylene and a small amount of a third monomer which is a non-conjugated diene, both of which are collectively referred to as ethylene-propylene rubber. The ethylene propylene rubber has no double bond in the molecule and can not be vulcanized by sulfur, thereby limiting the application of the ethylene propylene rubber; the side chain of the ethylene propylene diene monomer contains diene, so that the ethylene propylene diene monomer can be vulcanized by sulfur, various characteristics of the ethylene propylene diene monomer are kept, and the ethylene propylene diene monomer becomes a main variety of ethylene propylene rubber and is widely applied.
The role of the third monomer in ethylene-propylene rubber is to create unsaturation in the polymer by copolymerization with ethylene and propylene in order to effect vulcanization, so the third monomer must be selected to meet the following requirements: contains at most two unsaturated bonds in the molecule: one for the polymerization reaction to take place and the other for the vulcanization process. Common third monomers of ethylene propylene diene monomer produced industrially include Ethylidene Norbornene (ENB), dicyclopentadiene (DCPD), 1, 4-Hexadiene (HD), and among the common third monomers, ENB has high vulcanization speed, and the obtained vulcanized rubber has the advantages of high heat resistance, high tensile strength, small compression permanent deformation, high tensile strength and the like, so that the vulcanized rubber becomes the most common third monomer in the industrial production of ethylene propylene rubber.
In industrial production, the aim of reducing the production cost is generally achieved by a method for recovering and purifying a solvent. CN104031196A discloses an ethylene propylene rubber production process, which comprises five process steps of a feeding section, a polymerization reaction section, a monomer removal section, a product acquisition section and a solvent recovery section. The catalyst used in the polymerization reaction section is a metallocene catalyst, the catalyst has high catalytic activity efficiency, and the catalyst is occluded in an ethylene propylene rubber product after reaction, has no residue and does not need catalytic removal treatment. The polymerization section adopts five kettles connected in series, the feeding is supplemented in two and three stages, and the gas-liquid-solid (metallocene catalyst) three-phase reaction is carried out. The process adopts closed-loop circulation, can return to the kettle for cyclic utilization after the monomers which do not participate in the reaction are subjected to flash evaporation separation, improves the utilization rate of raw materials, obtains the ethylene propylene rubber product by changing the solubility parameter of the solvent, and has the advantages of energy conservation and high efficiency. However, this invention does not involve a recovery process of the third monomer, which adversely affects the subsequent use of the recovered solvent and the control of the production cost.
In the prior art, the recovery and purification processes of hexane, a solvent used in the ethylene propylene rubber industry and ENB, a third monomer mainly have the following problems:
(1) increase of energy and material consumption
The desalted water (DEW) pipe network used in the recovery and purification process generates a certain temperature rise in the use process, which causes the flow rate of DEW to exceed the designed operation flow rate of the rectifying tower, and the increase of the operation load simultaneously increases the consumption of steam used in the stripping.
(2) Poor separation effect
Because the temperature at the top of the rectifying tower is not easy to control, the hexane component separated from the top of the rectifying tower often contains a high proportion of ENB components, and the recycling of the solvent in the subsequent process is adversely affected.
(3) Influence environmental protection
As the temperature of the side line of the rectifying tower is difficult to control, a large amount of ENB is lost from the bottom of the tower, and the ENB has an unpleasant smell, which is an important factor influencing the surrounding environment of the device.
in view of the above problems, we have made a targeted improvement on the system for recovering the solvent in the production of ethylene propylene rubber, so that the above problems can be effectively solved.
Disclosure of Invention
Aiming at the problems in the recovery and purification of the solvent hexane and the third monomer diene in the industrial production process of the ethylene propylene rubber, the invention provides a novel recovery and purification method and a novel recovery and purification system, which realize the effective recovery and purification of the hexane and the preliminary separation of the diene and reduce the energy consumption and the environmental pollution.
The invention relates to a method for recovering and purifying a hexane solvent in ethylene propylene rubber production, which comprises the following steps:
Introducing a recovered solvent in the production of ethylene propylene rubber into a rectifying tower, obtaining hexane steam at the top of the rectifying tower after steam stripping operation under the condition of strictly controlling the temperature of each point of the rectifying tower, obtaining a mixture of unreacted diene and oligomer at the side line of the rectifying tower, and obtaining a polymer at the bottom of the rectifying tower;
Introducing the hexane steam into a first condenser, condensing and liquefying the hexane steam, and introducing the hexane steam into a storage tank to obtain purified hexane;
introducing the unliquefied impurities in the hexane steam after condensation in the first condenser into the second condenser, and recovering the unliquefied impurities as waste liquid after deep condensation and liquefaction;
And after the mixture of the unreacted diene and the oligomer is subjected to oil-water separation treatment, the water phase is circulated to the lower part of the rectifying tower, and the organic phase serving as the pre-purified diene is introduced into a subsequent third monomer purification unit to obtain the purified diene.
The method of the invention is characterized in that the temperature of each point of the rectifying tower is preferably controlled by introducing desalted water which is subjected to real-time temperature control by a cooler into the top of the rectifying tower and blowing steam into the bottom of the rectifying tower.
The method of the invention, wherein the temperatures of each point of the rectifying tower comprise tower top temperature, side line temperature and tower bottom temperature.
the method disclosed by the invention is characterized in that the top temperature of the rectifying tower is preferably controlled to be 60-64 ℃, the side temperature of the rectifying tower is preferably controlled to be 87-91 ℃, and the bottom temperature of the rectifying tower is preferably controlled to be 98-100 ℃.
The method of the invention is characterized in that the temperature range of the first condenser is preferably 20-30 ℃; the temperature range of the second condenser is preferably between 5 and 10 ℃.
the method is characterized in that the steam stripping is realized by blowing steam into the bottom of the rectifying tower, and the flow rate is preferably 1.0-1.4 tons/hour.
The method of the invention, wherein the flow rate of the recovered solvent is preferably 1.0-2.0 tons/hour.
The hexane recovery system for the method comprises a rectifying tower, a first condenser, a storage tank, an oil-water separation device, a second condenser and a waste liquid recovery tank; the rectifying tower comprises two tower plate groups, namely a first tower plate group and a second tower plate group from top to bottom, wherein a desalted water feeding port, a recovered solvent feeding port and three side line extraction ports are formed in the first tower plate group; the top steam outlet of the rectifying tower is connected to the inlet of the first condenser through a pipeline, and the side line extraction outlet of the rectifying tower is connected to the inlet of the oil-water separation device through a pipeline under the control of an extraction valve.
The hexane recovery system of the present invention, wherein the number of trays in the first tray group is preferably 9 to 11, and the number of trays in the second tray group is preferably 1 to 3.
the hexane recovery system is characterized in that the desalted water inlet is preferably positioned at the upper part of the first plate group of the rectifying tower, and the desalted water pipeline is preferably connected to the desalted water inlet of the rectifying tower through a desalted water cooler; the recovered solvent feed port is preferably positioned between the first plate group and the second plate group of the rectifying tower; the three side draws are preferably located at the three bottom layers of tower plates of the first tower plate group respectively.
The recovery system comprises a rectification tower, a reflux pump, a delivery pump, a third monomer recovery unit, a fourth monomer recovery unit.
The recovery system comprises a first condenser, a second condenser, a storage tank, a pipeline and a pipeline, wherein a liquid phase outlet of the first condenser is connected to the storage tank through the pipeline, a gas phase outlet of the first condenser is connected to the second condenser through the pipeline, and a gas phase outlet of the storage tank is connected to the second condenser through the pipeline.
The recovery system is characterized in that the outlet of the second condenser is connected to a waste liquid recovery tank through a pipeline.
The invention has the following beneficial effects:
(1) After the desalted water cooler is put into use, the consumption of desalted water and steam is obviously reduced, and the temperature of the rectifying tower is more reasonably controlled;
(2) The separation effect of the rectifying tower is obviously improved, and the content of alkadiene in hexane steam separated from the top of the tower is obviously reduced;
(3) The alkadiene content in the side stream component is improved, and the loss of the alkadiene in the recovery process is reduced.
Drawings
FIG. 1 is a schematic diagram showing the connection of the related devices of the system of the present invention
Wherein, 1 is a rectifying tower, 2 is a first condenser, 3 is a storage tank, 4 is a second condenser, 5 is a waste liquid recovery tank, 6 is an oil-water separation device, 7 is a reflux pump, 8 is a delivery pump, 9 is a third monomer recovery unit, 10 is a cutting pump, 11 is a recovered solvent feed pipeline, 12 is a side draw pipeline, 13 is a side draw pipeline, 14 is a side draw pipeline, 15 is a desalted water feed pipeline, 16 is a steam feed pipeline, 17 is a steam feed pipeline, 18 is a nitrogen feed pipeline, 19 is a desalted water cooler, 20 is a desalted water feed inlet, 21 is a recovered solvent feed inlet, 22 is a side draw outlet, 23 is a side draw outlet, 24 is a side draw outlet, 25 is a nitrogen feed inlet, 26 is a steam feed inlet, 27 is a steam feed inlet, 28 is an overhead steam outlet, 29 is a first condenser inlet, and 30 is a water phase outlet of the oil-water separation device, 31 is an organic phase outlet of the oil-water separation device, 32 is a liquid phase outlet of a first condenser, 33 is a gas phase outlet of the first condenser, 34 is a gas phase outlet of a storage tank, and 35 is an outlet of a second condenser.
Detailed Description
the following examples illustrate the invention in detail: the present example is carried out on the premise of the technical solution of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the following examples do not indicate process parameters of specific conditions, and generally follow conventional conditions.
The method of the invention is characterized in that the temperature of each point of the rectifying tower is preferably controlled by introducing desalted water which is subjected to real-time temperature control by a desalted water cooler into the top of the rectifying tower and blowing steam into the bottom of the rectifying tower.
the method of the invention, wherein the temperatures of each point of the rectifying tower comprise tower top temperature, side line temperature and tower bottom temperature.
The method disclosed by the invention is characterized in that the top temperature of the rectifying tower is preferably controlled to be 60-64 ℃, the side temperature of the rectifying tower is preferably controlled to be 87-91 ℃, and the bottom temperature of the rectifying tower is preferably controlled to be 98-100 ℃.
the method of the invention is characterized in that the temperature range of the first condenser is preferably 20-30 ℃; the temperature range of the second condenser is preferably between 5 and 10 ℃.
The method is characterized in that the steam stripping is realized by blowing steam into the bottom of the rectifying tower, and the flow rate is preferably 1.0-1.4 tons/hour.
The method of the invention, wherein the flow rate of the recovered solvent is preferably 1.0-2.0 tons/hour.
A hexane recovery system used for the method comprises a rectifying tower 1, a first condenser 2, a storage tank 3, an oil-water separation device 6, a second condenser 4 and a waste liquid recovery tank 5; the rectifying tower 1 comprises two tower plate groups, namely a first tower plate group and a second tower plate group from top to bottom, a desalted water feed port 20, a recovered solvent feed port 21 and three side line extraction ports 22, 23 and 24 are formed in the first tower plate group, a nitrogen feed port 25 is formed in the middle of the first tower plate group and the second tower plate group, steam feed ports 26 and 27 are formed in the lower part of the second tower plate group and the bottom of the rectifying tower respectively, and the bottom of the rectifying tower 1 is connected with an inlet and an outlet of a cutting pump 10 through pipelines respectively; an overhead vapor outlet 28 of the rectifying tower 1 is connected to an inlet 29 of the first condenser 2 through a pipeline, and side draw outlets 22, 23 and 24 of the rectifying tower 1 are respectively connected to the oil-water separation device 6 through side draw pipelines 12, 13 and 14 under the control of a draw valve.
The hexane recovery system of the present invention, wherein the number of trays in the first tray group is preferably 9 to 11, and the number of trays in the second tray group is preferably 1 to 3.
The hexane recovery system is characterized in that the desalted water inlet 20 is positioned at the upper part of the first plate group of the rectifying tower, and the desalted water pipeline 15 is connected to the desalted water inlet 20 of the rectifying tower 1 through a desalted water cooler 19; the recovered solvent feed port 21 is positioned between the first tower plate group and the second tower plate group of the rectifying tower 1, and the recovered solvent feed pipeline 11 is connected to the recovered solvent feed port 21; the three side draw ports 22, 23 and 24 are located at the bottom three trays of the first tray group, respectively.
In the recovery system of the present invention, the water phase outlet 30 of the oil-water separation device 6 is preferably connected to the rectifying tower 1 through a pipeline via the reflux pump 7, and the organic phase outlet 31 of the oil-water separation device 6 is preferably connected to the third monomer recovery unit 9 through a pipeline via the transfer pump 8.
The recovery system of the invention, wherein the liquid phase outlet 32 of the first condenser 2 is connected to the storage tank 3 through a pipeline, the gas phase outlet 33 of the first condenser 2 is connected to the second condenser 4 through a pipeline, and the gas phase outlet 34 of the storage tank 3 is connected to the second condenser 4 through a pipeline.
The recovery system according to the invention is characterized in that the outlet 35 of the second condenser 4 is connected to the waste liquid recovery tank 5 by means of a pipe.
The following are three comparative data tables of the material consumption and the separation effect when the method and the system are applied to recover and produce the hexane and the ENB of the ethylene propylene rubber with different ENB contents, so as to further understand the beneficial effects of the invention.
TABLE 1 comparative data of DEW feed rate consumed by the solvent recovery system in the production of 8% ENB ethylene propylene rubber
As can be seen from Table 1, after the desalted water cooler is put into use, the use amount of the desalted water is reduced to 6.73t/h from 8.29t/h before the desalted water cooler is put into use, the reduction is obvious, and the control of temperature points at each position of the rectifying tower is more reasonable.
TABLE 2 comparative data for steam consumption and DEW feed rates for solvent recovery systems in the production of ethylene propylene rubber without ENB
As can be seen from Table 2, after the transformation, the consumption of the desalted water and the steam is obviously reduced, particularly, the reduction amplitude is about 50 percent before the transformation is compared, and the purpose of energy conservation is achieved; and the temperature of each point of the rectifying tower is particularly and stably controlled, and the temperature of each point is controlled, so that the problems that the temperature fluctuation of each point is large before modification, and particularly the side-stream extraction temperature and the steam quantity are difficult to stably control are solved.
TABLE 3 comparative data for steam consumption and DEW feed and separation effectiveness for solvent recovery system in the production of ethylene propylene rubber having 2% ENB
As can be seen from Table 3, after the reforming, the material balance of the column tends to be reasonable, the components of each point are basically controlled, and the quality of the hexane is ensured. In the petroleum industry, the number of milligrams of bromine consumed by a 100 gram sample is known as the bromine index. The higher the bromine index, the higher the unsaturated hydrocarbon content in the sample. The higher the bromine index of the solvent recovered and purified in the production of ethylene propylene rubber, the lower the removal effect of the third monomer in the solvent. When the ethylene propylene rubber with the ENB content of 2% is produced, the solvent recovery system is started for 11 days, the bromine index of hexane is only increased to 418mg/100g from 243mg/100g before the start, and the ENB content in the recovered hexane is effectively controlled; the operation effect of the rectifying tower is consistent with the design, especially the amount of ENB carried by hexane at the top of the tower and the normal ENB side-stream extraction amount can be stabilized in the design range, and the content of ENB and unknown substances in the recovered hexane is reduced by 8.6 percent compared with that before the modification; the on-site peculiar smell is greatly reduced.
Claims (8)
1. A method for recovering and purifying hexane solvent in ethylene propylene rubber production comprises the following steps:
Introducing a recovered solvent in the production of ethylene propylene rubber into a rectifying tower, obtaining hexane steam at the top of the rectifying tower after steam stripping operation under the condition of controlling the temperature of each point of the rectifying tower, obtaining a mixture of unreacted diene and oligomer at the lateral line of the rectifying tower, and obtaining a polymer at the bottom of the rectifying tower;
Introducing the hexane steam into a first condenser, condensing and liquefying the hexane steam, and introducing the hexane steam into a storage tank to obtain purified hexane;
Introducing the unliquefied impurities in the hexane steam after condensation in the first condenser into the second condenser, and recovering the unliquefied impurities as waste liquid after deep condensation and liquefaction;
After the mixture of the unreacted diene and the oligomer is subjected to oil-water separation treatment, the water phase is circulated back to the lower part of the rectifying tower, the organic phase is used as pre-purified diene and is introduced into a subsequent third monomer purification unit to obtain purified diene,
wherein the temperature control of each point of the rectifying tower is realized by introducing desalted water which is subjected to real-time temperature control by a desalted water cooler into the top of the rectifying tower and blowing steam into the bottom of the rectifying tower,
wherein the temperatures of all points of the rectifying tower comprise the tower top temperature, the side line temperature and the tower bottom temperature,
Wherein the top temperature of the rectifying tower is controlled to be 60-64 ℃, the side temperature of the rectifying tower is controlled to be 87-91 ℃, the bottom temperature of the rectifying tower is controlled to be 98-100 ℃,
wherein the steam stripping is realized by blowing steam with the flow rate of 1.0 to 1.4 tons/hour into the bottom of the rectifying tower,
The rectifying tower comprises two tower plate groups, namely a first tower plate group and a second tower plate group from top to bottom, wherein the number of tower plates of the first tower plate group is 9-11, and the number of tower plates of the second tower plate group is 1-3.
2. The method of claim 1, wherein the temperature of the first condenser is in the range of 20 to 30 ℃; the temperature range of the second condenser is between 5 and 10 ℃.
3. The method according to claim 1, wherein the recovered solvent is introduced at a flow rate of 1.0 to 2.0 tons/hr.
4. The hexane recovery apparatus used in the method of claim 1, comprising a rectifying tower, a first condenser, a storage tank, an oil-water separation device, a second condenser and a waste liquid recovery tank; the rectifying tower comprises two tower plate groups, namely a first tower plate group and a second tower plate group from top to bottom, wherein a desalted water feeding port, a recovered solvent feeding port and three side line extraction ports are formed in the first tower plate group; the top steam outlet of the rectifying tower is connected to the inlet of the first condenser through a pipeline, and the side line extraction outlet of the rectifying tower is connected to the inlet of the oil-water separation device through a pipeline under the control of an extraction valve.
5. The hexane recovery apparatus according to claim 4, wherein the desalted water feed inlet is located at an upper portion of the first plate group of the rectification column, and the desalted water feed pipe is connected to the desalted water feed inlet of the rectification column through a desalted water cooler; the recovered solvent feed port is positioned between the first tower plate group and the second tower plate group of the rectifying tower; the three side draw outlets are respectively positioned at the three layers of tower plates at the bottommost layer of the first tower plate group.
6. The recovery apparatus according to claim 4, wherein the aqueous phase outlet of the oil-water separation apparatus is connected to the rectifying tower through a pipeline via a reflux pump, and the organic phase outlet of the oil-water separation apparatus is connected to the third monomer recovery unit through a pipeline via a transfer pump.
7. The recycling apparatus according to claim 4, wherein the liquid phase outlet of the first condenser is connected to a storage tank by a pipe, the gas phase outlet of the first condenser is connected to the second condenser by a pipe, and the gas phase outlet of the storage tank is connected to the second condenser by a pipe.
8. A recovery device as claimed in claim 4, in which the outlet of the second condenser is connected by a conduit to a waste recovery tank.
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| CN201510446041.8A CN106397089B (en) | 2015-07-27 | 2015-07-27 | Method and system for recovering and purifying hexane solvent in ethylene propylene rubber production |
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| CN113440884B (en) * | 2021-07-06 | 2022-09-20 | 万华化学（宁波）有限公司 | Tower set temperature self-adaptive adjusting method, system and storage medium |
| CN116832729A (en) * | 2023-03-21 | 2023-10-03 | 北京石油化工工程有限公司 | Process system for preparing vinyl rubbery copolymer |
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