CN111574398A - External micro-interface ammoximation reaction system and method - Google Patents
External micro-interface ammoximation reaction system and method Download PDFInfo
- Publication number
- CN111574398A CN111574398A CN202010284800.6A CN202010284800A CN111574398A CN 111574398 A CN111574398 A CN 111574398A CN 202010284800 A CN202010284800 A CN 202010284800A CN 111574398 A CN111574398 A CN 111574398A
- Authority
- CN
- China
- Prior art keywords
- rearrangement
- tank
- reaction
- oxime
- micro
- 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
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 100
- 238000000034 method Methods 0.000 title claims abstract description 25
- DKGAVHZHDRPRBM-UHFFFAOYSA-N Tert-Butanol Chemical compound CC(C)(C)O DKGAVHZHDRPRBM-UHFFFAOYSA-N 0.000 claims abstract description 157
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Natural products CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 claims abstract description 134
- 239000007788 liquid Substances 0.000 claims abstract description 82
- 238000006146 oximation reaction Methods 0.000 claims abstract description 67
- 238000005406 washing Methods 0.000 claims abstract description 56
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 52
- 238000006462 rearrangement reaction Methods 0.000 claims abstract description 50
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 44
- -1 toluene oxime Chemical class 0.000 claims abstract description 38
- 238000011084 recovery Methods 0.000 claims abstract description 25
- 238000000605 extraction Methods 0.000 claims abstract description 21
- 239000007791 liquid phase Substances 0.000 claims abstract description 16
- 238000003860 storage Methods 0.000 claims abstract description 15
- 238000001816 cooling Methods 0.000 claims abstract description 11
- 230000008707 rearrangement Effects 0.000 claims description 98
- VEZUQRBDRNJBJY-UHFFFAOYSA-N cyclohexanone oxime Chemical compound ON=C1CCCCC1 VEZUQRBDRNJBJY-UHFFFAOYSA-N 0.000 claims description 54
- 150000002923 oximes Chemical class 0.000 claims description 50
- 239000000463 material Substances 0.000 claims description 25
- 238000010992 reflux Methods 0.000 claims description 25
- 239000012071 phase Substances 0.000 claims description 18
- 239000000243 solution Substances 0.000 claims description 17
- 230000008569 process Effects 0.000 claims description 14
- 239000007864 aqueous solution Substances 0.000 claims description 11
- 239000007795 chemical reaction product Substances 0.000 claims description 7
- 230000008676 import Effects 0.000 claims description 6
- 230000003197 catalytic effect Effects 0.000 claims description 4
- 238000005086 pumping Methods 0.000 claims 1
- 238000012546 transfer Methods 0.000 abstract description 13
- 238000005265 energy consumption Methods 0.000 abstract description 8
- 239000007789 gas Substances 0.000 description 44
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 26
- JBKVHLHDHHXQEQ-UHFFFAOYSA-N epsilon-caprolactam Chemical compound O=C1CCCCCN1 JBKVHLHDHHXQEQ-UHFFFAOYSA-N 0.000 description 22
- 238000010521 absorption reaction Methods 0.000 description 21
- 238000011045 prefiltration Methods 0.000 description 11
- 229910021529 ammonia Inorganic materials 0.000 description 10
- 238000012856 packing Methods 0.000 description 10
- 239000000047 product Substances 0.000 description 10
- 238000007086 side reaction Methods 0.000 description 10
- 238000003809 water extraction Methods 0.000 description 10
- 239000012467 final product Substances 0.000 description 7
- 239000012295 chemical reaction liquid Substances 0.000 description 6
- 239000012535 impurity Substances 0.000 description 6
- 230000008901 benefit Effects 0.000 description 5
- 239000007810 chemical reaction solvent Substances 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 5
- 238000001914 filtration Methods 0.000 description 5
- 238000000746 purification Methods 0.000 description 5
- 238000000926 separation method Methods 0.000 description 5
- 238000004140 cleaning Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 238000006237 Beckmann rearrangement reaction Methods 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000000945 filler Substances 0.000 description 3
- 229910000856 hastalloy Inorganic materials 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000012074 organic phase Substances 0.000 description 3
- 230000005501 phase interface Effects 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 2
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 2
- 235000011130 ammonium sulphate Nutrition 0.000 description 2
- 239000008346 aqueous phase Substances 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 238000004134 energy conservation Methods 0.000 description 2
- HYYHQASRTSDPOD-UHFFFAOYSA-N hydroxylamine;phosphoric acid Chemical compound ON.OP(O)(O)=O HYYHQASRTSDPOD-UHFFFAOYSA-N 0.000 description 2
- 230000002401 inhibitory effect Effects 0.000 description 2
- 238000002347 injection Methods 0.000 description 2
- 239000007924 injection Substances 0.000 description 2
- DNYZBFWKVMKMRM-UHFFFAOYSA-N n-benzhydrylidenehydroxylamine Chemical compound C=1C=CC=CC=1C(=NO)C1=CC=CC=C1 DNYZBFWKVMKMRM-UHFFFAOYSA-N 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- HIFJUMGIHIZEPX-UHFFFAOYSA-N sulfuric acid;sulfur trioxide Chemical compound O=S(=O)=O.OS(O)(=O)=O HIFJUMGIHIZEPX-UHFFFAOYSA-N 0.000 description 2
- UGACIEPFGXRWCH-UHFFFAOYSA-N [Si].[Ti] Chemical compound [Si].[Ti] UGACIEPFGXRWCH-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- RWCCWEUUXYIKHB-UHFFFAOYSA-N benzophenone Chemical compound C=1C=CC=CC=1C(=O)C1=CC=CC=C1 RWCCWEUUXYIKHB-UHFFFAOYSA-N 0.000 description 1
- 239000012965 benzophenone Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003386 deoximation reaction Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002808 molecular sieve Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 230000017105 transposition Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C249/00—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton
- C07C249/04—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton of oximes
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C249/00—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton
- C07C249/04—Preparation of compounds containing nitrogen atoms doubly-bound to a carbon skeleton of oximes
- C07C249/14—Separation; Purification; Stabilisation; Use of additives
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D201/00—Preparation, separation, purification or stabilisation of unsubstituted lactams
- C07D201/02—Preparation of lactams
- C07D201/04—Preparation of lactams from or via oximes by Beckmann rearrangement
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D223/00—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom
- C07D223/02—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings
- C07D223/06—Heterocyclic compounds containing seven-membered rings having one nitrogen atom as the only ring hetero atom not condensed with other rings with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D223/08—Oxygen atoms
- C07D223/10—Oxygen atoms attached in position 2
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0093—Microreactors, e.g. miniaturised or microfabricated reactors
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention provides an external micro-interface ammoximation reaction system and method, which comprises an oximation reactor, a reaction clear liquid buffer tank, a tert-butyl alcohol recovery tower, an extraction tank, a water washing separator, a toluene oxime storage tank, a first rectifying tower, a second rectifying tower and a rearrangement reaction device, wherein the reaction clear liquid buffer tank is arranged in the reaction clear liquid buffer tank; the side wall of the oximation reactor is provided with a feed inlet which is connected with a micro-interface generator for dispersing the broken gas into bubbles; the middle part of the side wall of the first rectifying tower is provided with a first inlet, the bottom of the first rectifying tower is provided with a first outlet, the side wall of the second rectifying tower is provided with a second inlet by leaning on the second rectifying tower, the bottom of the second rectifying tower is provided with a second outlet, the first inlet is connected with the top of the toluene oxime storage tank so as to be used for standing and cooling before toluene oxime rectification, and the second outlet is connected with the rearrangement reaction device so as to carry out rearrangement reaction. The micro-interface generator is arranged in front of the oximation reactor, so that the mass transfer area between the ammonia gas and the liquid phase is increased, the temperature and the pressure of the oximation reaction are reduced, the energy consumption is effectively reduced, and the reaction efficiency is improved.
Description
Technical Field
The invention belongs to the technical field of micro-interface intensified reaction, and particularly relates to an external micro-interface ammoximation reaction system and method.
Background
Currently, caprolactam is mainly prepared from cyclohexanone oxime by beckmann rearrangement and transposition, and the main processes for preparing cyclohexanone oxime include Hydroxylamine Phosphate (HPO) represented by the tesmann technique and cyclohexanone ammoximation (HAO) which is developed autonomously in China. The latter takes silicon-titanium molecular sieve TS-1 as a catalyst, cyclohexanone, dilute hydrogen peroxide and ammonia as raw materials are synthesized into cyclohexanone-oxime in one step under certain operation conditions, and the process has mild reaction conditions, simple operation, high atom utilization rate and environmental friendliness, so that the process is favored by caprolactam industry in recent years. Although the cyclohexanone ammoximation process has obvious process advantages, the cyclohexanone ammoximation process also has some defects: on one hand, the gas-liquid phase mass transfer area of the existing oximation reactor is limited, the reaction mixed raw materials and ammonia gas cannot be fully mixed in the reaction process, so that the cyclohexanone is incompletely converted, the oximation conversion rate is low, and the occurrence of side reactions is increased; on the other hand, the ammoximation reaction is a strong exothermic reaction (301KJ/mol), the temperature is too high, the decomposition products of cyclohexanone and cyclohexanone oxime are increased, and the products are not easy to remove in the post-process, and the yield and the quality of the final product caprolactam are influenced. In order to improve the efficiency of cyclohexanone oximation reaction, reduce the reaction temperature and pressure and reduce the occurrence of side reactions, the improvement of the prior art is necessary.
In view of the above, the present invention is particularly proposed.
Disclosure of Invention
The first purpose of the invention is to provide an external micro-interface ammoximation reaction system, which can disperse and crush ammonia gas into micro bubbles with micron-sized diameter on one hand and increase the phase interface area between the ammonia gas and a liquid phase material on the other hand by arranging a micro-interface generator in front of an oximation reactor, so that the mass transfer space is fully satisfied, the retention time of the ammonia gas in the liquid phase is increased, and the consumption of the ammonia gas is reduced, thereby greatly improving the oximation reaction efficiency, effectively inhibiting side reactions and remarkably reducing the energy consumption in the reaction process; on the other hand, the reaction temperature and pressure are reduced, the decomposition products of cyclohexanone and cyclohexanone oxime are reduced, the yield and quality of the final product caprolactam are improved, the energy consumption is reduced, and the system safety is improved.
The second purpose of the invention is to provide a method for carrying out reaction by adopting the reaction system, the method has mild operation conditions, reduces the temperature and pressure of oximation reaction while ensuring the reaction efficiency, has high safety performance and low energy consumption, and achieves better reaction effect than the prior art.
In order to achieve the above purpose of the present invention, the following technical solutions are adopted:
the invention provides an external micro-interface ammoximation reaction system, which comprises an oximation reactor, a reaction clear liquid buffer tank, a tert-butyl alcohol recovery tower, an extraction tank, a water washing separator, a toluene oxime storage tank, a first rectifying tower, a second rectifying tower and a rearrangement reaction device, wherein,
the side wall of the oximation reactor is provided with a feed inlet, and the feed inlet is connected with a micro-interface generator for dispersing broken gas into bubbles; an external circulation device is arranged outside the oximation reactor and used for controlling the temperature inside the oximation reactor, one end of the external circulation device is connected with the side wall of the oximation reactor, and the other end of the external circulation device is connected with the micro-interface generator;
the bottom of the oximation reactor is connected with the reaction clear liquid buffer tank, and the material from the reaction clear liquid buffer tank is introduced from the middle section of the tert-butyl alcohol recovery tower for recovering tert-butyl alcohol; the extraction tank is provided with a liquid inlet and a light phase discharge port, the liquid inlet is connected with the bottom of the tert-butyl alcohol recovery tower, and the light phase discharge port is connected with the water washing separator to be used for washing toluene oxime solution; the process toluene oxime that the washing separator water washing was qualified gets into in the toluene oxime storage tank, the lateral wall middle part of first rectifying column is provided with first import, and the bottom is provided with first export, the lateral wall of second rectifying column is leaned on and is provided with the second import, and the bottom is provided with the second export, first import with the cooling of stewing earlier before toluene oxime rectification is connected in order to be used for at the top of toluene oxime storage tank, first export with second access connection, the second export with rearrangement reaction device connects and carries out the rearrangement reaction.
In the prior art, the cyclohexanone ammoximation reaction has the following problems: on one hand, the gas-liquid phase mass transfer area of the existing oximation reaction is limited, the reaction mixed raw materials and ammonia gas cannot be fully mixed in the reaction process, so that the cyclohexanone is incompletely converted, the oximation conversion rate is low, and the occurrence of side reactions is increased; on the other hand, the ammoximation reaction is a strong exothermic reaction, the temperature is too high, the decomposition products of cyclohexanone and cyclohexanone oxime are increased, and the products are not easy to remove in the post-process, thereby influencing the yield and the quality of the final product caprolactam. According to the external micro-interface ammoximation reaction system, after the micro-interface generator is arranged in front of the oximation reactor, on one hand, ammonia gas can be dispersed and crushed into micro bubbles with micron-sized diameters, and the phase interface area between the ammonia gas and a liquid-phase material is increased, so that the mass transfer space is fully satisfied, the retention time of the ammonia gas in the liquid phase is increased, the consumption of the ammonia gas is reduced, the oximation reaction efficiency is greatly improved, side reactions are effectively inhibited, and the energy consumption in the reaction process is remarkably reduced; on the other hand, the reaction temperature and pressure are reduced, the decomposition products of cyclohexanone and cyclohexanone oxime are reduced, the yield and quality of the final product caprolactam are improved, the energy consumption is reduced, and the system safety is improved.
Furthermore, the setting mode, the setting position and the number of the micro-interface generator are not limited; the micro-interface generator can be connected with the feed inlet of the oximation reactor in a welding or flange mode; in addition, more preferably, the oximation reactor can be provided with a plurality of micro-interface generators in series or in parallel, and the micro-interface generators can be connected with the feed inlet of the reactor.
Furthermore, the micro-interface generator is a pneumatic micro-interface generator, and the number of the micro-interface generators is at least more than one. The ammonia enters into the inside of pneumatic micro-interface generator, through the broken dispersion effect of pneumatic micro-interface generator, breaks the ammonia dispersion into the microbubble to reduce liquid film thickness, the effectual mass transfer area that has increased between ammonia and the liquid phase material reduces the mass transfer resistance, improves reaction efficiency.
Further, the rearrangement reaction device comprises a first-stage rearrangement tank, a second-stage rearrangement tank and a third-stage rearrangement tank which are sequentially connected in series; the tops of the first-stage rearrangement tank, the second-stage rearrangement tank and the third-stage rearrangement tank are connected with the second outlet through pipelines. The cyclohexanone oxime respectively enters a first-stage rearrangement tank, a second-stage rearrangement tank and a third-stage rearrangement tank according to a certain proportion, the cyclohexanone oxime is converted into caprolactam through Beckmann molecular rearrangement in the presence of fuming sulfuric acid, first-stage heavy discharge liquid in the first-stage rearrangement tank overflows from the upper part of the first-stage rearrangement tank and is mixed with bottom materials of the second-stage rearrangement tank, and then the mixture enters the second-stage rearrangement tank to react with newly added cyclohexanone oxime; and the second-stage heavy-discharge liquid in the second-stage rearrangement tank overflows from the upper part of the tank and is mixed with the bottom material of the third-stage rearrangement tank, then the mixture enters the third-stage rearrangement tank and reacts with the newly added cyclohexanone oxime, and the final product overflows from the upper part of the third-stage rearrangement tank and is collected.
More preferably, the rearrangement reaction device can also be provided with a plurality of rearrangement tanks connected in series to form a multi-stage continuous rearrangement reaction, and the tops of the plurality of rearrangement tanks connected in series are all connected with the second outlet. Through the multi-stage continuous rearrangement reaction, the reaction time of each stage of rearrangement reaction can be shortened, the occurrence of side reactions in the rearrangement process is reduced, and the yield of the product is improved.
Furthermore, the first-stage rearrangement tank, the second-stage rearrangement tank and the third-stage rearrangement tank are all provided with rearrangement liquid circulation pipelines for controlling the temperature in the tanks, and the material coming out of the previous-stage rearrangement tank is connected to the rearrangement liquid circulation pipeline of the next-stage rearrangement tank. Because the beckmann rearrangement reaction is exothermic reaction, the temperature is higher in the reaction process, a series of side reactions can be caused under the acidic condition, the ammonium sulfate serving as a byproduct can be greatly increased, and the purity of caprolactam is influenced, so that a rearrangement liquid circulating pipeline needs to be arranged, and the reaction heat is led out by utilizing the circulating heat of the circulating pipeline, so that the reaction is gentle, and the reaction temperature in the tank is reduced.
Furthermore, the rearrangement liquid circulating pipelines are respectively provided with a rearrangement circulating pump, a rearrangement heat exchanger and a three-way valve, and the three-way valve is positioned between the rearrangement circulating pump and the rearrangement heat exchanger; and a bypass channel is arranged and communicated with the three-way valve, and the bypass channel is used under the working condition of no heat exchange. In the initial stage of the rearrangement reaction, the temperature is low, the reaction liquid enters the rearrangement tank from the bypass channel to carry out the rearrangement reaction, along with the release of a large amount of heat in the process of the reaction, the reaction liquid carries out heat exchange cooling from the heat exchange channel, the heat generated by the reaction is removed, and then the reaction liquid circularly enters the rearrangement reaction tank to carry out the rearrangement reaction to form a rearrangement liquid circulating pipeline so as to keep the reaction temperature in the rearrangement tank within a certain range. Preferably, the plate heat exchanger is optimized to the rearrangement heat exchanger, and compared with other heat exchangers, the plate heat exchanger has the characteristics of high heat exchange efficiency, small heat loss, high efficiency, energy conservation, easiness in cleaning, convenience in dismounting and the like.
Further, an oxime cooler and an oxime buffer tank which are connected in sequence are arranged on a pipeline between the second outlet and the rearrangement reaction device and are used for cooling cyclohexanone oxime before rearrangement reaction, the oxime cooler is connected with the second outlet, and the oxime buffer tank is connected with the rearrangement reaction device. The rearrangement reaction is a strong exothermic reaction, so the cyclohexanone-oxime is cooled to a certain temperature before the rearrangement reaction and then enters the rearrangement reaction device, the oxime cooler is a shell-and-tube cooler, and the cooler has the advantages of simple structure, low manufacturing cost, wider flow cross section and easy scale cleaning. The material of shell-and-tube cooler is hastelloy, compares other materials, and hastelloy has better corrosion resistance and thermal stability, consequently adopts hastelloy material, can improve the life-span of cooler.
Furthermore, the first rectifying tower consists of a rectifying section and a stripping section, and the second rectifying tower consists of a stripping section. Methylbenzene oxime enters a first rectifying tower from a first inlet after being heated by a heater, methylbenzene basically not containing oxime is recycled from the top of the first rectifying tower, an oxime solution containing a small amount of methylbenzene in a tower kettle is discharged from a first outlet and enters a second rectifying tower through a second inlet, methylbenzene containing a small amount of oxime is evaporated from the top of the second rectifying tower, and cyclohexanone oxime in the tower kettle enters an oxime buffer tank after being cooled through a second outlet.
Furthermore, the rectifying section and the stripping section in the first rectifying tower can be formed by randomly combining a plurality of tower plates and fillers, preferably, the stripping section adopts a tower plate structure, and the rectifying section adopts a filler structure, because the pressure drop of the tower plates is larger and the pressure drop of the fillers is smaller; the stripping section of the second rectifying tower adopts a packing structure, the type of the packing is pall ring packing, and the packing has the characteristics of high production capacity, strong resistance, high operation elasticity and the like.
Further, a first tower top condenser is arranged at the tower top of the first rectifying tower, the first tower top condenser is connected with a first receiving tank, and the first receiving tank is connected with the side wall of the first rectifying tower through a conveying pump so as to be used for tower top reflux; the top of the second rectifying tower is provided with a second tower top condenser, the second tower top condenser is connected with a second receiving tank, and the second receiving tank is connected with a toluene oxime-removing tower to separate toluene and oxime.
Furthermore, the first rectifying tower and the second rectifying tower are both provided with a vacuumizing device to ensure that the rectifying towers operate under a vacuum condition. The stability and continuity of feeding and discharging can be ensured under the vacuum condition, thereby achieving the purpose of improving the rectification rate. The vacuumizing device is an injection pump, and the vacuumizing device continuously vacuumizes through the injection pump so as to maintain the vacuum degree in the tower.
Furthermore, a washing water circulation pipeline is arranged at the bottom of the water washing separator and used for returning washing water to the water washing separator for washing and purifying again; and a washing circulating pump is arranged on the washing water circulating pipeline. Through setting up the washing water circulation pipeline, can make the washing water return to the washing separator through the washing water circulation pipeline and carry out washing purification many times to avoid the waste of benzooxime. More advantageously, the washing water quantity can be adjusted by arranging the washing circulating pump, the load of the washing water is reduced, and the washing effect is improved.
Further, reaction system is including prefilter and the coalescer that connects gradually, the prefilter with the top of washing separator is connected to enter into the coalescer after being used for the benzoxim prefilter and separate impurity and accomplish the washing. After being washed by water, the toluene oxime firstly enters a prefilter for filtration, then enters a coalescer for further impurity separation and purification, and finally the toluene oxime with qualified concentration is sent into a toluene oxime tank; the prefilter can filter out larger solid particle impurities in a medium and can prevent a filter element of the coalescer from being blocked, and the filtering precision of the prefilter is less than or equal to 15 mu m.
Furthermore, the reaction system comprises a water extraction tower and an extraction liquid receiving tank which are connected in sequence and used for receiving an organic phase extracted from the top of the water extraction tower. And the organic phase extracted from the top of the water extraction tower overflows into the extraction liquid receiving tank, and then returns to the benzoximes cooler again through a delivery pump for cooling and enters the toluene oxime extraction system again for extraction and water washing, so that the waste of cyclohexanone-oxime is avoided.
Further, the reaction system comprises a tail gas absorption tower, the tail gas absorption tower is connected with the top of the oximation reactor, an absorption liquid outlet is further formed in the bottom of the tail gas absorption tower, and the absorption liquid outlet is connected with the oximation reactor and used for enabling absorption liquid to return to the oximation reactor again for utilization.
Further, a liquid inlet and a gas inlet are respectively arranged at the middle section of the tert-butyl alcohol recovery tower, and the liquid inlet is connected with the bottom of the reaction clear liquid buffer tank; the gas inlet is connected with the top of the reaction clear liquid buffer tank. The liquid in the reaction clear liquid buffer tank enters the tertiary butanol recovery tower from the liquid inlet, and the gas in the reaction clear liquid buffer tank enters the tertiary butanol recovery tower from the gas inlet, so that the gas inlet and the liquid inlet are arranged at the same time, because the material components in the reaction clear liquid buffer tank are relatively complex, most of the tertiary butanol exists in a liquid state, and a small amount of the tertiary butanol exists in a reaction product in a gaseous state, and the arrangement of the gas inlet and the liquid inlet is a double-material inlet, so that the tertiary butanol can be fully recovered and utilized.
Further, the reaction system comprises a tert-butyl alcohol reflux tank, a non-condensable gas outlet is formed in the tert-butyl alcohol reflux tank, and non-condensable gas in the tert-butyl alcohol reflux tank enters the tail gas absorption tower to be recycled after being mixed with tail gas through the non-condensable gas outlet.
Furthermore, the reaction system also comprises a circulating tertiary butanol tank, the top of the circulating tertiary butanol tank is connected with the bottom of the tertiary butanol reflux tank, and the bottom of the circulating tertiary butanol tank is connected with the bottom of the oximation reactor, so that the tertiary butanol can be reused as the reaction solvent. A small part of condensate in the tertiary butanol reflux tank is used as tower top reflux, and the rest of condensate enters the oximation reactor through the circulating tertiary butanol tank to be reused as a reaction solvent, so that the use cost of the tertiary butanol is reduced.
In addition, the invention also provides an oximation reaction method, which comprises the following steps:
after ammonia gas is dispersed and crushed into micro bubbles, the micro bubbles and liquid-phase materials are subjected to catalytic oximation reaction; collecting reaction products in a clear liquid mode and then recovering tert-butyl alcohol; carrying out toluene extraction and water washing on the oxime aqueous solution after the tert-butyl alcohol is recovered; rectifying the washed toluene oxime, and then carrying out rearrangement reaction.
Further, ammonia gas is introduced into a micro-interface generator arranged in front of the oximation reactor and is crushed into micro-bubbles with the diameter of micron level, and the ammonia gas is dispersed and crushed into the micro-bubbles and then carries out catalytic oximation reaction with liquid phase materials.
In the catalytic oximation reaction process, the unreacted gas is recycled, the reaction product is collected in a clear liquid mode and then enters a reaction clear liquid buffer tank, and then enters a tert-butyl alcohol recovery tower to recover tert-butyl alcohol in the reaction product, and the recovered tert-butyl alcohol enters the oximation reactor again to be used as a reaction solvent; cooling the oxime aqueous solution after recovering the tert-butyl alcohol by a toluene oxime cooler, then feeding the cooled oxime aqueous solution into an extraction tank, extracting oxime from the oxime aqueous solution into a toluene phase by utilizing the solubility of toluene to oxime, separating the toluene oxime solution from a light phase discharge port of the extraction tank, feeding the separated toluene oxime solution into a water washing separator, finishing water washing in the water washing separator and a coalescer by utilizing desalted water, and feeding qualified toluene oxime into a toluene oxime tank from the coalescer; and then the mixture is heated by a heater and then enters a first rectifying tower, toluene which does not contain oxime basically is recovered from the tower top of the first rectifying tower, an oxime solution containing a small amount of toluene in the tower kettle flows out from a first outlet and enters a second rectifying tower through a second inlet, and cyclohexanone oxime in the tower kettle of the second rectifying tower enters a rearrangement reaction device for rearrangement reaction after being cooled through a second outlet.
Furthermore, the temperature of the oximation reaction is 80-84 ℃, and the pressure is 0.19-0.22 MPa.
Compared with the prior art, the invention has the beneficial effects that:
according to the invention, after the micro-interface generator is arranged in front of the oximation reactor, on one hand, ammonia gas can be dispersed and crushed into micro-bubbles with micron-sized diameters, and the phase interface area between the ammonia gas and a liquid phase material is increased, so that the mass transfer space is fully satisfied, the retention time of the ammonia gas in the liquid phase is increased, and the consumption of the ammonia gas is reduced, thereby greatly improving the oximation reaction efficiency, effectively inhibiting side reactions and remarkably reducing the energy consumption in the reaction process; on the other hand, the reaction temperature and pressure are reduced, the decomposition products of cyclohexanone and cyclohexanone oxime are reduced, the yield and quality of the final product caprolactam are improved, the energy consumption is reduced, and the system safety is improved.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:
fig. 1 is a schematic structural diagram of an external micro-interface ammoximation reaction system provided by an embodiment of the invention.
Description of the drawings:
a 10-oximation reactor; 11-feed port-;
12-a tail gas outlet; 20-reaction clear liquid buffer tank;
a 30-tert-butanol recovery column; 31-a liquid inlet;
32-gas inlet; a 33-oxime aqueous solution outlet;
40-extraction tank; 41-liquid inlet;
42-light phase discharge port; 43-water phase discharge port;
50-water washing separator; a 60-toluene oxime storage tank;
70-a first rectification column; 71-a first inlet;
72-first outlet; 710-a first overhead condenser;
720-a first receiving tank; 80-a second rectification column;
81-a second inlet; 82-a second outlet;
810-a second overhead condenser; 820-a second receiving tank;
90-rearrangement reaction device; 91-first-stage rearrangement tank;
92-a secondary rearrangement tank; 93-three-stage rearrangement tank;
910-rearrangement of circulation pumps; 920-a rearrangement heat exchanger;
930-three-way valve; 100-a micro-interface generator;
110-an outer filter device; a 120-tert-butyl alcohol reflux tank;
121-noncondensable gas outlet; 130-recycle tert-butanol tank;
140-a water extraction column; 150-a pre-filter;
160-a coalescer; 170-extract receiving tank;
180-toluene deoximation column; 190-a heater;
a 200-oxime cooler; 210-oxime surge tank;
220-a tail gas absorption tower; 221-absorption liquid outlet.
Detailed Description
The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and the detailed description, but those skilled in the art will understand that the following described embodiments are some, not all, of the embodiments of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" 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.
In order to more clearly illustrate the technical solution of the present invention, the following description is made in the form of specific embodiments.
Examples
Referring to fig. 1, the external micro-interface ammoximation reaction system of the embodiment of the present invention includes an oximation reactor 10, a reaction clear solution buffer tank 20, a tert-butyl alcohol recovery tower 30, an extraction tank 40, a water washing separator 50, a toluene oxime storage tank 60, a first rectification tower 70, a second rectification tower 80, and a rearrangement reaction device 90, wherein, the side wall of the oximation reactor 10 is provided with a feed inlet 11, the feed inlet 11 is connected with a micro-interface generator 100 for dispersing the broken gas into bubbles, concretely, the micro-interface generator 100 is a pneumatic micro-interface generator, ammonia gas enters the interior of the pneumatic micro-interface generator, the ammonia gas is dispersed and crushed into micro bubbles through the crushing and dispersing action of the pneumatic micro interface generator, thereby reducing the thickness of the liquid film, effectively increasing the mass transfer area between the ammonia gas and the liquid phase material, reducing the mass transfer resistance and improving the reaction efficiency.
An external circulation device is arranged outside the oximation reactor 10 and used for controlling the temperature inside the oximation reactor 10, one end of the external circulation device is connected with the side wall of the oximation reactor 10, and the other end of the external circulation device is connected with the micro-interface generator 100; the bottom of the oximation reactor 10 is connected with a reaction clear liquid buffer tank 20, and preferably, an external filtering device 110 is arranged on a connecting pipeline between the reaction clear liquid buffer tank 20 and the discharge hole 11 to prevent the catalyst from entering the reaction clear liquid buffer tank 20 after the filter inside the oximation reactor 10 is blocked. The material from the reaction clear liquid buffer tank 20 is introduced from the middle section of the tert-butyl alcohol recovery tower 30 for recovering the tert-butyl alcohol, specifically, the middle section of the tert-butyl alcohol recovery tower 30 is respectively provided with a liquid inlet 31 and a gas inlet 32, and the liquid inlet 31 is connected with the bottom of the reaction clear liquid buffer tank 20; the gas inlet 32 is connected with the top of the reaction clear liquid buffer tank 20, and the gas inlet 32 and the liquid inlet 31 are arranged at the same time because the material components in the reaction clear liquid buffer tank are relatively complex, most of the tertiary butanol exists in a liquid state, and a small amount of the tertiary butanol exists in a reaction product in a gaseous state, so that the double-material inlet of the gas inlet and the liquid inlet is arranged, and the tertiary butanol can be fully recycled.
Further, the top of the tert-butyl alcohol recovery tower 30 is preferably connected with the tert-butyl alcohol reflux tank 120 through two top condensers, a reflux pipeline is further arranged between the tert-butyl alcohol recovery tower 30 and the tert-butyl alcohol reflux tank 120, one end of the reflux pipeline is connected with the top of the tert-butyl alcohol recovery tower 30, the other end of the reflux pipeline is connected with the bottom of the tert-butyl alcohol reflux tank 120 so as to return the substances in the tert-butyl alcohol reflux tank 120 to continue separation and purification, and the recovery purity of the tert-butyl alcohol can be improved through multiple times of reflux. In this embodiment, the reaction system further includes a circulating tert-butyl alcohol tank 130, the top of the circulating tert-butyl alcohol tank 130 is connected to the bottom of the tert-butyl alcohol reflux tank 120, the bottom of the circulating tert-butyl alcohol tank 130 is connected to the bottom of the oximation reactor 10, a small part of the condensate in the tert-butyl alcohol reflux tank 120 is refluxed as the top of the tower, and the rest of the condensate enters the oximation reactor 10 through the circulating tert-butyl alcohol tank 130 and is reused as a reaction solvent, so that the use cost of tert-butyl alcohol is reduced.
The bottom of the tert-butyl alcohol recovery tower 30 of this embodiment is provided with an oxime aqueous solution outlet 33, the extraction tank 40 is provided with a liquid inlet 41, a light phase discharge port 42 and a water phase discharge port 43, the liquid inlet 41 is connected with the oxime aqueous solution outlet 33, the light phase discharge port 42 is connected with the water washing separator 50 for washing toluene oxime solution, and the water phase discharge port 43 is connected with the water extraction tower 140 for extracting and recovering oxime in the water phase.
In this embodiment, the bottom of the washing separator 50 is provided with a washing water circulation pipeline for returning the washing water to the washing separator 50 for washing and purifying again, and by providing the washing water circulation pipeline, the washing water can be returned to the washing separator through the washing water circulation pipeline for washing and purifying for many times, thereby avoiding the waste of the benzoximes. Still be provided with the recovery pipeline between the middle part of washing water circulation pipeline and the top of water extraction tower 140, the recovery pipeline is used for letting in the water extraction tower 140 with the oxime-containing water that the washing water circulation pipeline came out and aqueous phase discharge gate 43 come out together and carries out the multistage extraction to retrieve the oxime in the aqueous phase, water extraction tower 140 still is connected with extract receiving tank 170, the organic phase that water extraction tower 140 top of the tower was gathered overflows to extract receiving tank 170 in, then return to the benzoxim extraction system again through the delivery pump and extract and the washing, thereby the waste of cyclohexanone oxime has been avoided.
In addition, the reaction system of this embodiment further includes a prefilter 150 and a coalescer 160 connected in sequence, the prefilter 150 is connected to the top of the water washing separator 50, and is used for filtering the benzoximes, and then the filtered benzoximes enter the coalescer 160 to separate impurities, thereby completing water washing. After being washed by water, the toluene oxime enters a prefilter 150 for filtration, then enters a coalescer 160 for further impurity separation and purification, and finally the toluene oxime with qualified concentration is sent into a toluene oxime storage tank 60.
The middle part of the side wall of the first rectifying tower 70 is provided with a first inlet 71, the bottom of the first rectifying tower 70 is provided with a first outlet 72, the side wall of the second rectifying tower 80 is provided with a second inlet 81 on the upper part, the bottom of the second rectifying tower is provided with a second outlet 82, the first inlet 71 is connected with the top of the toluene oxime storage tank 60 and is used for standing and cooling before rectification of toluene oxime, the first outlet 72 is connected with the second inlet 81, the second outlet 82 is connected with the rearrangement reaction device 90 for rearrangement reaction, and a heater 190 is arranged on a pipeline between the toluene oxime storage tank 60 and the first inlet 71. Specifically, the first rectifying column 70 is composed of a rectifying section and a stripping section, and preferably, the stripping section adopts a tray structure, and the rectifying section adopts a packing structure, because the pressure drop of the tray is large and the pressure drop of the packing is small; a first tower top condenser 710 is arranged at the tower top of the first rectifying tower 70, the first tower top condenser 710 is connected with a first receiving tank 720, and the first receiving tank 720 is connected with the side wall of the first rectifying tower 70 through a transfer pump for tower top reflux; the second rectifying tower 80 is composed of a stripping section, preferably, the stripping section adopts a packing structure, the type of the packing is pall ring packing, and the packing has the characteristics of high production capacity, strong resistance, high operation elasticity and the like; the top of the second rectifying tower 80 is provided with a second tower top condenser 810, the second tower top condenser 810 is connected with a second receiving tank 820, and the second receiving tank 820 is connected with the toluene oxime removing tower 180 for separating toluene and oxime. The first rectifying tower 70 and the second rectifying tower 80 are each provided with a vacuum evacuation device to ensure that the rectifying towers operate under vacuum conditions, and it is to be understood that the vacuum evacuation device is not particularly limited herein as long as it can evacuate.
In addition, an oxime cooler 200 and an oxime buffer tank 210 which are connected in sequence are further arranged on the pipeline between the second outlet 82 and the rearrangement reaction device 90 for cooling the cyclohexanone oxime before the rearrangement reaction, the oxime cooler 200 is connected with the second outlet 82, and the oxime buffer tank 210 is connected with the rearrangement reaction device. Since the rearrangement reaction is a strong exothermic reaction, the cyclohexanone oxime is cooled to a certain temperature before the rearrangement reaction and then enters the rearrangement reaction device 90, and the oxime cooler 200 is a shell-and-tube cooler, which has the advantages of simple structure, low cost, wide flow cross section and easy scale cleaning.
In this embodiment, the rearrangement reaction apparatus 90 includes a first-stage rearrangement tank 91, a second-stage rearrangement tank 92, and a third-stage rearrangement tank 93 connected in series in sequence; the tops of the first-stage rearrangement tank 91, the second-stage rearrangement tank 92 and the third-stage rearrangement tank 93 are connected with the second outlet 82 through pipelines. It is to be understood that the rearrangement reaction apparatus 90 may further be provided with a plurality of rearrangement tanks connected in series to form a multi-stage continuous rearrangement reaction, and the tops of the plurality of rearrangement tanks connected in series may be connected to the second outlet. Through the multi-stage continuous rearrangement reaction, the reaction time of each stage of rearrangement reaction can be shortened, the occurrence of side reactions in the rearrangement process is reduced, and the yield of the product is improved.
Further, the first-stage rearrangement tank 91, the second-stage rearrangement tank 92 and the third-stage rearrangement tank 93 are all provided with rearrangement liquid circulation pipelines for controlling the temperature in the tanks, and the material coming out of the previous-stage rearrangement tank is connected to the rearrangement liquid circulation pipeline of the next-stage rearrangement tank. Because the beckmann rearrangement reaction is exothermic reaction, the temperature is higher in the reaction process, a series of side reactions can be caused under the acidic condition, the ammonium sulfate serving as a byproduct can be greatly increased, and the purity of caprolactam is influenced, so that a rearrangement liquid circulating pipeline needs to be arranged, and the reaction heat is led out by utilizing the circulating heat of the circulating pipeline, so that the reaction is gentle, and the reaction temperature in the tank is reduced.
Specifically, the rearrangement liquid circulating pipelines are provided with a rearrangement circulating pump 910, a rearrangement heat exchanger 920 and a three-way valve 930; the three-way valve 930 is positioned between the rearrangement circulating pump 910 and the rearrangement heat exchanger 920; a bypass passage is provided in communication with the three-way valve 930 for use in operating conditions where heat is not exchanged. In the initial stage of the rearrangement reaction, the temperature is low, the reaction liquid enters the rearrangement tank from the bypass channel to carry out the rearrangement reaction, along with the release of a large amount of heat in the process of the reaction, the reaction liquid carries out heat exchange cooling from the heat exchange channel, the heat generated by the reaction is removed, and then the reaction liquid circularly enters the rearrangement reaction tank to carry out the rearrangement reaction to form a rearrangement liquid circulating pipeline so as to keep the reaction temperature in the rearrangement tank within a certain range. The plate heat exchanger is preferably selected as the rearrangement heat exchanger 920, and compared with other heat exchangers, the plate heat exchanger has the characteristics of high heat exchange efficiency, small heat loss, high efficiency, energy conservation, easiness in cleaning, convenience in dismounting and the like.
In the above embodiment, the top of the oximation reactor 10 is further provided with a tail gas outlet 12, the tail gas outlet 12 is connected to the tail gas absorption tower 220, the bottom of the tail gas absorption tower 220 is further provided with an absorption liquid outlet 221, and the absorption liquid outlet 221 is connected to the oximation reactor 10 for the absorption liquid to return to the oximation reactor again for use. The tertiary butanol reflux tank 120 is provided with a non-condensable gas outlet 121, and the non-condensable gas in the tertiary butanol reflux tank 120 is mixed with the tail gas through the non-condensable gas outlet 121 and then enters the tail gas absorption tower 220 for recycling.
The working process and principle of the external micro-interface ammoximation reaction system of the invention are briefly explained below.
The ammonia gas is introduced into the micro-interface generator 100 arranged in front of the oximation reactor, so that the ammonia gas is crushed into micro-bubbles with the diameter of micron level, and the dispersed and crushed micro-bubbles and the liquid phase mixed raw material are fully emulsified, thereby effectively increasing the mass transfer area of gas phase and liquid phase and reducing the mass transfer resistance.
The emulsified liquid after being fully emulsified enters an oximation reactor 10 to carry out oximation reaction under the action of a catalyst, wherein the temperature in the oximation reactor 10 is 80-84 ℃, and the pressure is 0.19-0.22 MPa. The ammoximation reaction is a strong exothermic reaction, and an external circulation device is arranged outside the oximation reactor 10 so as to control the temperature inside the reactor.
In the reaction process, unreacted ammonia, alcohol and other gases enter the tail gas absorption tower 220 after being cooled from the tail gas outlet 12, the tail gas absorption tower 220 absorbs the ammonia and the alcohol in the unreacted ammonia and alcohol into absorption liquid by using desalted water, and the absorption liquid enters the oximation reactor 10 for repeated recycling after coming out from the absorption liquid outlet 221. The oximation reaction products (cyclohexanone oxime, ammonia, a small amount of tertiary butanol and the like) enter a reaction clear liquid buffer tank 20 in a clear liquid mode, then enter a tertiary butanol recovery tower through a liquid inlet 31 and a gas inlet 32 of the tertiary butanol recovery tower 30 respectively for recovering the tertiary butanol, mixed distillate containing water, ammonia and the tertiary butanol distilled from the tower top of the tertiary butanol recovery tower 30 enters a tertiary butanol reflux tank 120 after being cooled by a tower top condenser, and uncondensed gas enters a tail gas absorption tower 220 for recovering the ammonia after being mixed with tail gas of an oximation reactor 10 through an uncondensed gas outlet 121. A small part of condensate in the tertiary butanol reflux tank 120 is used as tower top reflux, and the rest of condensate enters the oximation reactor 10 through the circulating tertiary butanol tank 130 to be reused as reaction solvent, so that the use cost of the tertiary butanol is reduced.
The oxime aqueous solution is cooled to a certain temperature after coming out of an oxime aqueous solution outlet 33 of the tert-butanol tower 30, and then enters an extraction tank 40, and oxime is extracted from the oxime aqueous solution to a toluene phase by utilizing the solubility of toluene to oxime, so that the separation of oxime and water is realized. The benzophenone oxime solution comes out from a light phase discharge port 42 of the extraction tank 40 and enters a water washing separator 50, is washed with desalted water, is filtered by a prefilter 150 and then enters a coalescer 160 for further impurity separation and purification, and finally, the benzophenone oxime with qualified concentration is sent to a benzophenone storage tank 60. Wherein, the washing water 0 containing about 1% oxime and a small amount of dissolved toluene is merged with the oxime-containing water from the water phase discharge port 43 and then is introduced into the water extraction tower 140 for multi-stage extraction, thereby recovering the oxime in the water phase.
Toluene oxime in the toluene oxime storage tank 60 is heated by a heater 190 and then enters the first rectifying tower 70 from a first inlet 71, toluene which does not contain oxime is recovered from the top of the first rectifying tower 70, an oxime solution containing a small amount of toluene in the tower bottom is discharged from a first outlet 72 and enters the second rectifying tower 80 through a second inlet 81, toluene containing a small amount of oxime is distilled out from the top of the second rectifying tower 80, and cyclohexanone oxime in the tower bottom enters an oxime buffer tank 210 after being cooled by an oxime cooler 200 through a second outlet 82.
The cyclohexanone oxime in the oxime buffer tank 210 respectively enters a first-stage rearrangement tank 91, a second-stage rearrangement tank 92 and a third-stage rearrangement tank 93 according to a certain proportion, the cyclohexanone oxime is converted into caprolactam through Beckmann molecular rearrangement in the presence of fuming sulfuric acid, first-stage heavy discharge liquid in the first-stage rearrangement tank 91 overflows from the upper part of the first-stage rearrangement tank and is mixed with bottom materials of the second-stage rearrangement tank 92, and then the first-stage heavy discharge liquid enters the second-stage rearrangement tank 92 to react with newly added cyclohexanone oxime; and the second-stage heavy discharged liquid in the second-stage rearrangement tank 92 overflows from the upper part of the tank and is mixed with the bottom material of the third-stage rearrangement tank 93, then the mixture enters the third-stage rearrangement tank 93 to react with the newly added cyclohexanone oxime, and the final product overflows from the upper part of the third-stage rearrangement tank 93 and is collected.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. An external micro-interface ammoximation reaction system is characterized by comprising an oximation reactor, a reaction clear liquid buffer tank, a tert-butyl alcohol recovery tower, an extraction tank, a water washing separator, a toluene oxime storage tank, a first rectifying tower, a second rectifying tower and a rearrangement reaction device, wherein,
the side wall of the oximation reactor is provided with a feed inlet, and the feed inlet is connected with a micro-interface generator for dispersing broken gas into bubbles; an external circulation device is arranged outside the oximation reactor and used for controlling the temperature inside the oximation reactor, one end of the external circulation device is connected with the side wall of the oximation reactor, and the other end of the external circulation device is connected with the micro-interface generator;
the bottom of the oximation reactor is connected with the reaction clear liquid buffer tank, and the material from the reaction clear liquid buffer tank is introduced from the middle section of the tert-butyl alcohol recovery tower for recovering tert-butyl alcohol; the extraction tank is provided with a liquid inlet and a light phase discharge port, the liquid inlet is connected with the bottom of the tert-butyl alcohol recovery tower, and the light phase discharge port is connected with the water washing separator to be used for washing toluene oxime solution; the process toluene oxime that the washing separator water washing was qualified gets into in the toluene oxime storage tank, the lateral wall middle part of first rectifying column is provided with first import, and the bottom is provided with first export, the lateral wall of second rectifying column is leaned on and is provided with the second import, and the bottom is provided with the second export, first import with the cooling of stewing earlier before toluene oxime rectification is connected in order to be used for at the top of toluene oxime storage tank, first export with second access connection, the second export with rearrangement reaction device connects and carries out the rearrangement reaction.
2. The external micro-interface ammoximation reaction system of claim 1, wherein the micro-interface generator is a pneumatic micro-interface generator, and the number of the micro-interface generator is at least more than one.
3. The external micro-interface ammoximation reaction system of claim 1, wherein the rearrangement reaction device comprises a first-stage rearrangement tank, a second-stage rearrangement tank and a third-stage rearrangement tank which are connected in series in sequence; the tops of the first-stage rearrangement tank, the second-stage rearrangement tank and the third-stage rearrangement tank are connected with the second outlet through pipelines.
4. The external micro-interface ammoximation reaction system of claim 3, wherein the first-stage rearrangement tank, the second-stage rearrangement tank and the third-stage rearrangement tank are all provided with rearrangement liquid circulation pipelines for controlling the temperature in the tanks, and the material from the previous-stage rearrangement tank is connected to the rearrangement liquid circulation pipeline of the next-stage rearrangement tank.
5. The external micro-interface ammoximation reaction system according to claim 4, wherein the heavy liquid discharge circulation pipelines are respectively provided with a rearrangement circulation pump, a rearrangement heat exchanger and a three-way valve, and the three-way valve is positioned between the rearrangement circulation pump and the rearrangement heat exchanger; and a bypass channel is arranged and communicated with the three-way valve, and the bypass channel is used under the working condition of no heat exchange.
6. The external micro-interface ammoximation reaction system according to claim 1, wherein an oxime cooler and an oxime buffer tank which are connected in sequence are arranged on a pipeline between the second outlet and the rearrangement reaction device and are used for cooling cyclohexanone oxime before the rearrangement reaction, the oxime cooler is connected with the second outlet, and the oxime buffer tank is connected with the rearrangement reactor.
7. The external micro-interface ammoximation reaction system of claim 1, wherein the first rectification column consists of a rectification section and a stripping section, and the second rectification column consists of a stripping section.
8. The external micro-interface ammoximation reaction system of claim 7, wherein a first overhead condenser is arranged at the top of the first rectification column, the first overhead condenser is connected with a first receiving tank, and the first receiving tank is connected with the side wall of the first rectification column through a delivery pump for overhead reflux; the top of the second rectifying tower is provided with a second tower top condenser, the second tower top condenser is connected with a second receiving tank, and the second receiving tank is connected with a toluene oxime-removing tower to separate toluene and oxime.
9. The external micro-interface ammoximation reaction system of claim 1, wherein the first rectification column and the second rectification column are provided with a vacuum pumping device to ensure that the rectification columns operate under vacuum conditions.
10. The oximation reaction method by adopting the external micro-interface ammoximation reaction system of any one of claims 1 to 8, which is characterized by comprising the following steps:
after ammonia gas is dispersed and crushed into micro bubbles, the micro bubbles and liquid-phase materials are subjected to catalytic oximation reaction; collecting reaction products in a clear liquid mode and then recovering tert-butyl alcohol; carrying out toluene extraction and water washing on the oxime aqueous solution after the tert-butyl alcohol is recovered; rectifying the washed toluene oxime, and then carrying out rearrangement reaction;
preferably, the temperature of the oximation reaction is 80-84 ℃, and the pressure is 0.19-0.22 MPa.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010284800.6A CN111574398A (en) | 2020-04-13 | 2020-04-13 | External micro-interface ammoximation reaction system and method |
| PCT/CN2020/092779 WO2021208201A1 (en) | 2020-04-13 | 2020-05-28 | External micro-interface ammoximation reaction system and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010284800.6A CN111574398A (en) | 2020-04-13 | 2020-04-13 | External micro-interface ammoximation reaction system and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111574398A true CN111574398A (en) | 2020-08-25 |
Family
ID=72089916
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010284800.6A Pending CN111574398A (en) | 2020-04-13 | 2020-04-13 | External micro-interface ammoximation reaction system and method |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN111574398A (en) |
| WO (1) | WO2021208201A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115974720A (en) * | 2023-01-09 | 2023-04-18 | 衢州巨化锦纶有限责任公司 | Method for preparing ketoxime by two-stage ammoximation reaction |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102675176A (en) * | 2012-05-31 | 2012-09-19 | 中国天辰工程有限公司 | Method for producing caprolactam by taking high-purity benzene as raw material |
| CN205948418U (en) * | 2016-08-11 | 2017-02-15 | 湖北三宁化工股份有限公司 | A economizer for cyclohexanone oxime extraction |
| CN210045215U (en) * | 2019-01-29 | 2020-02-11 | 南京延长反应技术研究院有限公司 | Low-pressure gas-liquid reinforced emulsion bed reaction device |
-
2020
- 2020-04-13 CN CN202010284800.6A patent/CN111574398A/en active Pending
- 2020-05-28 WO PCT/CN2020/092779 patent/WO2021208201A1/en active Application Filing
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102675176A (en) * | 2012-05-31 | 2012-09-19 | 中国天辰工程有限公司 | Method for producing caprolactam by taking high-purity benzene as raw material |
| CN205948418U (en) * | 2016-08-11 | 2017-02-15 | 湖北三宁化工股份有限公司 | A economizer for cyclohexanone oxime extraction |
| CN210045215U (en) * | 2019-01-29 | 2020-02-11 | 南京延长反应技术研究院有限公司 | Low-pressure gas-liquid reinforced emulsion bed reaction device |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115974720A (en) * | 2023-01-09 | 2023-04-18 | 衢州巨化锦纶有限责任公司 | Method for preparing ketoxime by two-stage ammoximation reaction |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2021208201A1 (en) | 2021-10-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111574399A (en) | Reaction system and method for ammoximation and recovery of tert-butyl alcohol | |
| CN111470941B (en) | High-quality cyclohexanol production device and process | |
| CN111569789A (en) | Micro-interface reinforced cyclohexanone ammoximation reaction system and method | |
| CN110845734B (en) | System and method for hydrolyzing organochlorosilane and refining hydrochloric acid | |
| CN111574398A (en) | External micro-interface ammoximation reaction system and method | |
| CN213506678U (en) | External micro-interface ammoximation reaction system | |
| CN107556213B (en) | A kind of technique of cyclohexanone oxamidinating and the technique for manufacturing caprolactam | |
| CN213506677U (en) | Reaction system for ammoximation and recovery of tert-butyl alcohol | |
| CN111574418A (en) | Built-in micro-interface ammoximation reaction system and method | |
| CN114773230B (en) | Purifying device and method for methyl polyphenylmethane and polyurethane solution | |
| CN218834066U (en) | Novel separation system for acrylic acid device | |
| CN213078416U (en) | Built-in micro-interface ammoximation reaction system | |
| CN114436889B (en) | Ammonia oximation reaction and separation integration method and device thereof | |
| CN211752616U (en) | Caprolactam device is refined in crystallization | |
| CN210085331U (en) | Cyclohexanone oxime purification system in caprolactam production process | |
| CN111608910B (en) | Application and system of Roots liquid ring vacuum pump unit in ammoximation process production | |
| CN215855847U (en) | Cyclohexane purifying device in cyclohexanone oxime solvent rearrangement process | |
| CN216703401U (en) | High-efficient composite set that retrieves of solvent chlorobenzene in naphthol production | |
| CN113877232A (en) | Method and system for treating aniline-containing gas | |
| CN218046519U (en) | System for be arranged in desorption polymer polyol monomer | |
| CN217535507U (en) | Device for removing waste water and ammonia gas as reaction raw materials in ammoximation ammonia still | |
| CN214763389U (en) | Rectification energy-saving device in cyclohexanone oxime production process by cyclohexanone ammoximation method | |
| CN215975598U (en) | Device for refining cyclohexanone by cyclohexanol dehydrogenation | |
| CN219272164U (en) | System for recycling and purifying dibasic acid in adipic acid production waste liquid | |
| CN220328612U (en) | Heterogeneous ammoximation reaction separation device |
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: 20200825 |
|
| RJ01 | Rejection of invention patent application after publication |