CN109232516B - Multifunctional membrane synthesis trioxymethylene and DMM 3-8 Apparatus and method of (2) - Google Patents
Multifunctional membrane synthesis trioxymethylene and DMM 3-8 Apparatus and method of (2) Download PDFInfo
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- CN109232516B CN109232516B CN201811323228.9A CN201811323228A CN109232516B CN 109232516 B CN109232516 B CN 109232516B CN 201811323228 A CN201811323228 A CN 201811323228A CN 109232516 B CN109232516 B CN 109232516B
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- BGJSXRVXTHVRSN-UHFFFAOYSA-N 1,3,5-trioxane Chemical group C1OCOCO1 BGJSXRVXTHVRSN-UHFFFAOYSA-N 0.000 title claims abstract description 91
- 239000012528 membrane Substances 0.000 title claims abstract description 39
- 238000000034 method Methods 0.000 title claims abstract description 31
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 7
- 238000003786 synthesis reaction Methods 0.000 title claims abstract description 7
- 238000007254 oxidation reaction Methods 0.000 claims abstract description 124
- 230000003647 oxidation Effects 0.000 claims abstract description 100
- NKDDWNXOKDWJAK-UHFFFAOYSA-N dimethoxymethane Chemical compound COCOC NKDDWNXOKDWJAK-UHFFFAOYSA-N 0.000 claims abstract description 96
- 239000000047 product Substances 0.000 claims abstract description 90
- 238000000605 extraction Methods 0.000 claims abstract description 82
- 238000006555 catalytic reaction Methods 0.000 claims abstract description 62
- 238000006243 chemical reaction Methods 0.000 claims abstract description 54
- 238000000926 separation method Methods 0.000 claims abstract description 24
- 238000006116 polymerization reaction Methods 0.000 claims abstract description 21
- 230000008569 process Effects 0.000 claims abstract description 9
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 4
- 239000003054 catalyst Substances 0.000 claims description 143
- 239000007789 gas Substances 0.000 claims description 72
- 239000012071 phase Substances 0.000 claims description 62
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 claims description 57
- 238000010992 reflux Methods 0.000 claims description 52
- 238000012856 packing Methods 0.000 claims description 43
- 239000000463 material Substances 0.000 claims description 37
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 33
- 229910001220 stainless steel Inorganic materials 0.000 claims description 32
- 239000007791 liquid phase Substances 0.000 claims description 31
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 30
- 239000000945 filler Substances 0.000 claims description 27
- 239000010935 stainless steel Substances 0.000 claims description 26
- 239000007864 aqueous solution Substances 0.000 claims description 23
- 230000018044 dehydration Effects 0.000 claims description 23
- 238000006297 dehydration reaction Methods 0.000 claims description 23
- 239000000203 mixture Substances 0.000 claims description 23
- 239000011347 resin Substances 0.000 claims description 23
- 229920005989 resin Polymers 0.000 claims description 23
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 21
- 239000007788 liquid Substances 0.000 claims description 19
- 238000009833 condensation Methods 0.000 claims description 15
- 230000005494 condensation Effects 0.000 claims description 15
- 239000002253 acid Substances 0.000 claims description 14
- 238000002156 mixing Methods 0.000 claims description 14
- 238000004064 recycling Methods 0.000 claims description 14
- 239000002918 waste heat Substances 0.000 claims description 14
- 238000005194 fractionation Methods 0.000 claims description 13
- 239000006260 foam Substances 0.000 claims description 11
- 238000010438 heat treatment Methods 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 230000003197 catalytic effect Effects 0.000 claims description 9
- 239000003795 chemical substances by application Substances 0.000 claims description 9
- DSMZRNNAYQIMOM-UHFFFAOYSA-N iron molybdenum Chemical compound [Fe].[Fe].[Mo] DSMZRNNAYQIMOM-UHFFFAOYSA-N 0.000 claims description 9
- 238000003491 array Methods 0.000 claims description 8
- 238000011049 filling Methods 0.000 claims description 8
- 239000003566 sealing material Substances 0.000 claims description 8
- 239000003930 superacid Substances 0.000 claims description 7
- 230000009471 action Effects 0.000 claims description 6
- 229910010293 ceramic material Inorganic materials 0.000 claims description 6
- 239000002131 composite material Substances 0.000 claims description 6
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 claims description 6
- 238000007789 sealing Methods 0.000 claims description 6
- 239000010865 sewage Substances 0.000 claims description 6
- 238000010304 firing Methods 0.000 claims description 5
- 238000005260 corrosion Methods 0.000 claims description 4
- 238000005192 partition Methods 0.000 claims description 4
- 238000005245 sintering Methods 0.000 claims description 4
- 238000000429 assembly Methods 0.000 claims description 3
- 230000000712 assembly Effects 0.000 claims description 3
- 230000009977 dual effect Effects 0.000 claims description 3
- 230000008676 import Effects 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- -1 polytetrafluoroethylene Polymers 0.000 claims description 3
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims description 3
- 238000004804 winding Methods 0.000 claims description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 2
- 238000006482 condensation reaction Methods 0.000 claims description 2
- 229910052760 oxygen Inorganic materials 0.000 claims description 2
- 239000001301 oxygen Substances 0.000 claims description 2
- 239000007787 solid Substances 0.000 claims description 2
- 230000007613 environmental effect Effects 0.000 abstract description 5
- 230000004044 response Effects 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 14
- 230000002194 synthesizing effect Effects 0.000 description 14
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 10
- 239000004480 active ingredient Substances 0.000 description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000000243 solution Substances 0.000 description 5
- 230000007547 defect Effects 0.000 description 4
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 229910021536 Zeolite Inorganic materials 0.000 description 3
- 150000001335 aliphatic alkanes Chemical class 0.000 description 3
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 3
- 239000000919 ceramic Substances 0.000 description 3
- 150000001924 cycloalkanes Chemical class 0.000 description 3
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000002808 molecular sieve Substances 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 3
- 230000002195 synergetic effect Effects 0.000 description 3
- 239000010457 zeolite Substances 0.000 description 3
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000007171 acid catalysis Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000012467 final product Substances 0.000 description 2
- 239000007792 gaseous phase Substances 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 230000003204 osmotic effect Effects 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000007036 catalytic synthesis reaction Methods 0.000 description 1
- 238000003889 chemical engineering Methods 0.000 description 1
- 239000013064 chemical raw material Substances 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 210000003298 dental enamel Anatomy 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000012847 fine chemical Substances 0.000 description 1
- MGJURKDLIJVDEO-UHFFFAOYSA-N formaldehyde;hydrate Chemical compound O.O=C MGJURKDLIJVDEO-UHFFFAOYSA-N 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D323/00—Heterocyclic compounds containing more than two oxygen atoms as the only ring hetero atoms
- C07D323/04—Six-membered rings
- C07D323/06—Trioxane
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/48—Preparation of compounds having groups
- C07C41/50—Preparation of compounds having groups by reactions producing groups
- C07C41/56—Preparation of compounds having groups by reactions producing groups by condensation of aldehydes, paraformaldehyde, or ketones
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/48—Preparation of compounds having groups
- C07C41/58—Separation; Purification; Stabilisation; Use of additives
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a multifunctional membrane synthesis trioxymethylene and DMM 3‑8 Comprises a heat exchanger, a methylal oxidation reactor, an extraction catalytic reaction tower, an extraction tower, a mixer, a multi-section fixed bed reactor and a fractionating tower which are connected in sequence. Air and methylal are heated by a heat exchanger and then enter a methylal oxidation reactor for oxidation reaction, oxidation products with high temperature are obtained after the oxidation reaction, the oxidation products with low temperature are obtained after the oxidation reaction enters the heat exchanger for heat exchange, the oxidation products with low temperature are then enter an extraction catalytic reaction tower for polymerization reaction, trioxymethylene is obtained after extraction and separation of the polymerization products, the trioxymethylene is mixed with methylal and then enters a multi-section fixed bed reactor for reaction to synthesize DMMn, and the DMMn of the reaction products is fractionated to obtain the DMM product 3‑8 . The invention has mild process conditions, short process flow, small investment and quick response; high efficiency, low consumption, cleanness and environmental protection.
Description
Technical Field
The invention relates to a methylal oxidation method, in particular to a device and a method for synthesizing trioxymethylene and DMMn by using a multifunctional membrane, belonging to the technical field of fine chemical engineering.
Background
Trioxymethylene is an important chemical raw material and has very wide application. The prior art has a mature synthetic technology route: the trioxymethylene is synthesized by taking sulfuric acid as a catalyst, and a 35-50% formaldehyde aqueous solution is taken as a raw material, so that the process for synthesizing the trioxymethylene has the inherent defects: the three wastes are discharged more, the production environment is poor, the flow is long, the investment is large, the corrosion of production equipment is serious, and the like, so the development of a new technology with high efficiency, energy conservation, cleanness and environmental protection is imperative.
The existing synthesis methods are as follows: oxidizing methanol, absorbing oxidized product water, generating formaldehyde water solution with the content of 35-50%, decompressing and concentrating, heating to 100 ℃, entering an enamel reaction kettle, catalyzing with 2-10% sulfuric acid, evaporating and concentrating the trioxymethylene water solution, extracting and refining again, and drying to obtain a final product. The technology is a new technology for synthesizing trioxymethylene and further producing DMMn by directly introducing methylal oxidation products into a multi-section and multifunctional membrane assembly tubular bed catalytic tower, wherein the multifunctional membrane integrates dehydration and catalysis, and under the action of an extracting agent, the dehydration, catalysis and extraction synergistic effects simultaneously occur.
Disclosure of Invention
Aiming at the inherent shortages of the catalytic synthesis of trioxymethylene by the sulfuric acid method in the prior art, the invention provides a device and a method for synthesizing trioxymethylene and DMMn by a multifunctional membrane, overcomes the defects and drawbacks of the existing water absorption technology, concentration technology, sulfuric acid catalysis technology, extraction drying technology and the like, and creates a method and a device with mild process conditions, short process flow, small investment, quick response, high efficiency, low consumption, cleanness and environmental protection.
In order to achieve the above purpose, the present invention adopts the following technical scheme:
the invention firstly provides a multifunctional membrane synthesized trioxymethylene and DMM 3-8 The device comprises a heat exchanger, a methylal oxidation reactor, an extraction catalytic reaction tower, an extraction separation tower, a mixer, a multi-stage fixed bed reactor and a fractionating tower which are sequentially connected, wherein air and methylal firstly enter a heat exchanger shell side to be heated and then enter the methylal oxidation reactor to perform oxidation reaction, an oxidation product with high temperature is obtained by the oxidation reaction, the oxidation product with low temperature is obtained after heat exchange in the heat exchanger tube side, the oxidation product with low temperature is further subjected to polymerization reaction in the extraction catalytic reaction tower, the polymerization product is extracted and separated to obtain a product trioxymethylene, and the trioxymethylene and methylal are further mixed in the mixer Mixing, then feeding the mixture into a multi-stage fixed bed reactor to react and synthesize DMMn, and fractionating the DMMn reaction product to obtain the final product DMM 3-8 The method comprises the steps of carrying out a first treatment on the surface of the The method is characterized in that:
the heat exchanger is a shell-and-tube heat exchanger, a cold material inlet 6A is arranged above the side wall of the shell side, a hot material outlet 6B is arranged below the side wall of the shell side, a feed inlet 6D is arranged at the bottom of the shell side, and a discharge outlet 6C is arranged at the top of the shell side; wherein: the cold material inlet 6A is hot in connection with a device capable of providing air and/or methylal;
the methylal oxidation reactor, the top be equipped with feed inlet 1A, the bottom is equipped with discharge gate 1B, the top of lateral wall is equipped with import 1D, the below is equipped with export 1C, wherein: the feed inlet 1A is connected with a hot material outlet 6B of the heat exchanger; the discharge port 1B is connected with a feed port 6D of the heat exchanger; a waste heat boiler is arranged between the inlet 1D and the outlet 1C, the outlet 1C is connected with the inlet of the waste heat boiler, the inlet 1D is connected with the outlet of the waste heat boiler, and the waste heat boiler provides heat for oxidation reaction;
the extraction catalytic reaction tower is provided with an exhaust port 2C at the top, a discharge port 2B at the bottom, a feed port 2A at the side wall of the bottom, an extractant feed port 2D above the side wall, and a water removal port 2E at the middle lower part of the side wall; wherein: the feed inlet 2A is connected with the discharge outlet 6C of the heat exchanger; the extractant charging port 2D is connected with a device capable of providing extractant; the exhaust port 2C is divided into two paths, one path is connected with a cold substance inlet 6A of the heat exchanger so as to return air and recycle the air, and the other path is directly connected with an exhaust gas treatment system and is used for exhausting gas after treatment; the dewatering port 2E is connected with a sewage treatment system, and the dewatered water enters the sewage treatment system for treatment;
The top of the extraction separation tower is provided with a gas phase outlet 4B, the bottom of the extraction separation tower is provided with a discharge outlet 4D, a feed inlet 4A is arranged above the side wall, and a return port 4C is arranged above the other side wall; wherein: the feed inlet 4A is connected with the discharge outlet 2B of the extraction catalytic reaction tower; the gas phase outlet 4B is sequentially connected with a condenser I, a condensing tank I and a reflux pump I; the outlet of the reflux pump I is divided into two paths, one path is connected with the reflux port 4C, and the other path is connected with the extractant charging port 2D of the extraction catalytic tower so as to recycle the extractant;
the mixer is provided with a feed inlet 14A, a discharge outlet 14C and a methylal inlet 14B; wherein: the feed inlet 14A is connected with the discharge outlet 4D of the extraction and separation tower; the methylal inlet 14B is connected to a device capable of providing methylal;
the top of the multistage fixed bed reactor is provided with a feeding reflux port 12A, the bottom of the multistage fixed bed reactor is provided with a discharge port 12C, and the side wall of the multistage fixed bed reactor is provided with a feeding port 12B; wherein: the feed inlet 12B is connected with the discharge outlet 14C of the mixer; the feeding return port 12A is divided into two paths, wherein one path is also connected with the discharge port 14C of the mixer, and the mixed materials are fed from the top and the side wall simultaneously, so that the full chemical reaction can be carried out in the fixed bed reactors of different sections in the multi-section fixed bed reactor;
The finished product fractionating tower, the top be equipped with gaseous phase export 13C, the bottom is equipped with discharge gate 13D, the lateral wall top is equipped with return port 13B, the middle part is equipped with feed inlet 13A, wherein: the feed inlet 13A is connected with the discharge outlet 12C of the multistage fixed bed reactor; the gas phase outlet 13C is sequentially connected with a condenser II, a condensing tank II and a reflux pump II; the outlet of the reflux pump II is divided into two paths, one path is connected with a reflux port 13B, and the other path is connected with the other path of the feed reflux port 12A of the multi-section fixed bed reactor; discharge port 13D and collecting or receiving finished DMM 3-8 Is connected with the device of the device.
In the above technical scheme, the methylal oxidation reactor is filled with a catalyst a, wherein the catalyst a is an iron-molybdenum catalyst, and the iron-molybdenum catalyst is preferably the same as the type and the proportion of the active component or the active catalyst of the catalyst used in the utility model patent CN201710307041.9, the utility model patent CN201720485329.0 or the utility model patent CN 201720483709.0.
In the above technical scheme, the structure of the methylal oxidation reactor is the same as that of the equipment for oxidizing methanol in the utility model patent CN 201720483709.0: the feed inlet 1A and the discharge outlet 1B are identical to the feed inlet and the discharge outlet of the methanol oxidation equipment, and the inlet 1D and the outlet 1C are arranged above and below the side wall of the shell of the methanol oxidation equipment.
In the above technical scheme, the extraction catalytic reaction tower, the internals include: demister, distributor, packing subassembly: the uppermost end in the extraction catalytic reaction tower is provided with a foam remover and a distributor below the foam remover; a plurality of sections of filler components are filled under the distributor, and a redistributor is arranged between each section of filler components; the filler assembly is communicated with the adjacent distributor and the redistributor;
the packing component is a multifunctional membrane component and comprises a plurality of vertically arranged up-and-down through tubes which are arranged into a tube bed and fixed by a tube plate, a plurality of small holes are formed in the whole body of the tube, the fired up-and-down through functional tubes are inserted into the tube, the inner surfaces of the functional tubes are compositely fired to form a functional membrane, and the functional tubes are filled with packing;
sealing materials are arranged at the upper end and the lower end of a gap between the tube array and the functional tube for sealing and fixing; the filler component is communicated with the adjacent distributor and the redistributor through the functional pipe to form a reaction channel; a dehydration runner is formed among the filler component, the redistributor and the side wall of the reaction tower;
the top of the reaction tower is provided with the exhaust port 2C, the bottom of the reaction tower is provided with the discharge port 2B, the side wall of the bottom of the reaction tower is provided with the feed port 2A, the lowest filler component is provided with the water removal port 2E on the side wall of the reaction tower, and the uppermost distributor of the reaction tower is communicated with the extractant feed port 2D arranged on the side wall of the reaction tower;
The tube plates at the bottom layer are closed water receiving plates, all the tube plates above the bottom layer are communicated through downcomers, a vacuumizing port is arranged on the tube plate at the highest layer and is connected with an external vacuumizing system, and all the spaces outside the tube arrays of each section, which are communicated by the downcomers, are vacuumized to form negative pressure.
Diameter of the small hole1-50mm.
The functional pipe is made of ceramic materials through sintering; the functional membrane is prepared by composite firing of any one of ceramic materials, diatomite materials, ZSM-5, SAPO-34 or zeolite molecular sieves and the inner surface of the functional tube.
The filler is a cylindrical regular filler of a stainless steel corrugated wire mesh.
The foam remover, the distributor and the redistributor are all internally formed by stainless steel corrugated wire meshes; the distributor and the redistributor are respectively provided with a plurality of diversion ports communicated with the functional pipe.
The sealing material is a polytetrafluoroethylene sealing gasket or a metal winding gasket, and an anti-corrosion rubber gasket.
In the technical scheme, the packing assembly is filled in sections, the filling amount of the packing assembly is N sections, N is more than or equal to 1 and less than or equal to 100, and the height of each section is 1-3m; each section of filling functional pipe 253 is M, and M is more than or equal to 1 and less than or equal to 5000; each pipe diameter is D, and D is more than or equal to 5 and less than or equal to 200cm.
In the above technical scheme, the extractant added into the extraction catalytic reaction tower from the extractant feed inlet 2D is any one of pure benzene, aromatic hydrocarbon, alkane with carbon number more than 4 and cycloalkane with carbon number more than 4, or a mixture of two or more of them mixed in any proportion.
In the technical scheme, the extraction and separation tower is internally provided with tower internals, wherein the tower internals are any one of structured packing and tower plates; if the packing is structured packing, the number of the packing sections is N, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3 meters; if the plate is a column plate, the number of theoretical plates is M, and M is less than or equal to 1 and less than or equal to 100; a reboiler I is arranged below the side wall.
In the above technical scheme, the number of layers N of the fixed bed in the multistage fixed bed reactor is: 1-10, each layer of fixed bed is filled with a catalyst B; and a reboiler II is arranged below the side wall of the multistage fixed bed reactor.
In the technical scheme, the catalyst B is a strong acid resin catalyst, a high temperature resistant strong acid resin catalyst and a super acid resin catalyst; preferably spherical or beaded high-temperature resistant strong-acid resin catalyst or a module catalyst with the catalyst active ingredients of strong-acid resin catalyst and high-temperature resistant super-acid resin catalyst; wherein the modular catalyst is constructed as in patent 201620189729.2.
In the technical scheme, the fractionating tower is internally provided with tower internals, wherein the tower internals are any one of structured packing and tower plates; if the packing is structured packing, the number of the packing sections is N, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3 meters; if the plate is a column plate, the number of theoretical plates is M, and M is less than or equal to 1 and less than or equal to 100; a reboiler III is arranged below the side wall.
The invention also provides a multifunctional membrane synthesis trioxymethylene and a DMM 3-8 Comprising the steps of:
(1) Oxidation reaction: preheating methylal and air to 100-200 ℃, carrying out oxidation reaction under the catalysis of a catalyst A, obtaining an oxidation product with higher temperature after the oxidation reaction, and obtaining an oxidation product with reduced temperature after heat exchange;
(2) Polymerization reaction: the oxidation product with reduced temperature is polymerized under the catalysis of the functional film material to generate trioxymethylene aqueous solution; extracting the trioxymethylene aqueous solution by an extracting agent to form an extracting solution containing trioxymethylene, wherein one part of reaction residual gas is exhausted, and the other part of reaction residual gas is returned to the step (1) for recycling;
(3) Extraction and fractionation: fractionating the extract containing trioxymethylene obtained in the step (3) under a heating state to obtain a gas phase and a liquid phase; the gas phase is an extractant, a liquid phase extractant is obtained after condensation, a part of the liquid phase extractant flows back, and the other part returns to the step (2) for recycling; the liquid phase is high-purity trioxymethylene liquid;
(4) Mixing: fully mixing the high-purity trioxymethylene liquid (To) obtained in the step (3) with methylal (M1) To obtain a mixture, and then carrying out a reaction for synthesizing DMMn;
(5) Synthesizing DMMn: the mixture obtained in the step (4) reacts under the catalysis of the catalyst B to generate a DMMn product;
(6) And (3) product fractionation: fractionating the DMMn product obtained in the step (5) under a heating state to obtain a gas phase and a liquid phase; the gas phase is excessive methylal, part of the methylal is refluxed after condensation, and the other part of methylal is returned to the step (4) for recycling; the liquid phase is the product DMM 3-8 。
In the above technical solution, as shown in fig. 1, the method specifically includes the following steps:
(1) Oxidation reaction: the methylal and air enter the shell pass of the heat exchanger from the cold material inlet 6A for preheating, are led out from the hot material outlet 6B after being preheated to 100-200 ℃, are led into the methylal oxidation reactor from the feed inlet 1A, and are subjected to oxidation reaction under the catalysis of the catalyst A in the methylal oxidation reactor; the temperature of the oxidation product at the discharge port 1B of the methylal oxidation reactor is 200-450 ℃; the oxidation product with the temperature of 200-450 ℃ is led out from a discharge port 1B and is led into a tube side of a heat exchanger from a feed port 6D for heat exchange, and is led out from a discharge port 6C and is led into an extraction catalytic reaction tower from a feed port 2A after the temperature is reduced to 50-100 ℃;
(2) Polymerization reaction: the oxidation product in the step (1) is in a gas phase, and is led into a tube side of a multifunctional membrane component in the extraction catalytic reaction tower through a feed inlet 2A, and is subjected to polymerization reaction under the catalysis of a functional membrane of the multifunctional membrane component to generate trioxymethylene aqueous solution; the oxidation products which do not react completely continue to ascend, and the generated trioxymethylene aqueous solution also continues to ascend along with the airflow of the oxidation products, so that the trioxymethylene aqueous solution is extracted and absorbed by the extractant added from the 2D extractant charging port from top to bottom, and the density of the extractant increases after absorbing the trioxymethylene and gradually descends to the bottom of the tower; simultaneously, under the dehydration action of the functional film, the water in the trioxymethylene aqueous solution is gradually removed so that the concentration of the trioxymethylene is higher and the trioxymethylene also gradually descends, and the concentration of the trioxymethylene in the upward oxidation product gas flow is gradually reduced until the concentration is zero; the upward gas-phase oxidation product also contains gas-phase formaldehyde, and the gas-phase formaldehyde can be extracted by the extractant from top to bottom and absorbed, so that a liquid-phase extractant containing formaldehyde is generated, the density of the extractant containing formaldehyde is increased, the extractant gradually descends in the tower, and the upward formaldehyde, the gas-phase formaldehyde and the downward formaldehyde in the liquid phase continue to undergo polymerization reaction under the catalysis of the functional film, so that the reaction of formaldehyde in the oxidation product is complete; the residual gas of the reaction can continuously go upward to the demister in the tower, the demister thoroughly intercepts the extractant carried in the demister, one part of the residual gas is processed and exhausted to the exhaust port 2C, and the other part of the residual gas is led into the heat exchanger through the cold material inlet 6A and returns to the oxidation reactor for recycling after being heated together with methylal according to the operation in the step (1); under the dehydration of the functional film material, the water in the trioxymethylene aqueous solution is gradually removed, the shell side of the extraction catalytic reaction tower is controlled to be negative pressure, and under the dual functions of the functional film and the negative pressure, the removed water is discharged from a dehydration port 2E; the extracting agent containing the trioxymethylene is led out from the discharge port 2B and is led into the extraction and separation tower from the feed port 4A;
(3) Extraction and fractionation: after the extracting agent containing the trioxymethylene obtained in the step (2) enters a stripping and separating tower, fractionating the extracting agent in a heating state of a reboiler I of the fractionating tower to obtain a gas phase and a liquid phase; the gas phase is an extractant, the gas phase is discharged from a gas phase outlet 4B and enters a condenser I for condensation, the liquid extractant obtained by condensation sequentially flows through a condensing tank I and a reflux pump I and is divided into two paths, one path of extractant flows back into the extraction separation tower from a reflux port 4C, and the other path of extractant returns into the extraction catalytic reaction tower from an extractant charging port 2D for recycling; the liquid phase is high-purity trioxymethylene liquid, and is led out from a discharge port 4D at the bottom of the tower and is led into a mixer from a feed port 14A;
(4) Mixing: introducing a high-purity trioxymethylene liquid (To) into the mixer through a feed port 14A, and introducing methylal (M1) into the mixer through a methylal inlet 14B; the trioxymethylene and the methylal are fully mixed in a mixer to obtain a mixture, the mixture is led out from a discharge hole 14C, and the mixture is led into a multi-section fixed bed reactor through a feed return hole 12A at the top and a feed hole 12B at the side wall;
(5) Synthesizing DMMn: the mixture obtained in the step (4) enters a multi-stage fixed bed reactor, and is subjected to condensation reaction under the catalysis of a catalyst B in the reactor to generate DMMn, wherein the DMMn is led out from a discharge hole 12C and is led into a finished product fractionating tower from a feed hole 13A;
(6) And (3) product fractionation: after the DMMn obtained in the step (5) enters a fractionating tower, fractionating the DMMn in a heating state of a reboiler III to obtain a gas phase and a liquid phase, wherein the gas phase is excessive methylal (M1), and the liquid phase is a product DMM 3-8 The method comprises the steps of carrying out a first treatment on the surface of the The gas phase is discharged through a gas phase outlet 13C and enters a condenser II for coolingCondensing, namely separating methylal obtained by condensation into two paths after sequentially flowing through a condensing tank II and a reflux pump II, wherein one path of methylal flows back to the fractionating tower from a reflux port 13B, and the other path of methylal returns to the multi-section fixed bed reactor from a feed reflux port 12A for recycling; product DMM 3-8 Is discharged from the discharge port 13D to be collected.
In the above technical scheme, in the step (1), after the methylal is mixed with air, the mass content of oxygen is as follows: 5-20%, and the space velocity of the feeding mass is 0.1-5.0h -1 。
In the above technical scheme, in the step (1), the catalyst a is an iron-molybdenum catalyst, and the iron-molybdenum catalyst is preferably the same as the type and the proportion of the active component or the active catalyst of the catalyst used in the utility model patent CN201710307041.9, the utility model patent CN201720485329.0 or the utility model patent CN 201720483709.0.
In the above technical scheme, in the step (1), the reaction conditions in the methylal oxidation reactor are as follows: the temperature is 200-450 ℃, and the pressure is normal or micro-positive pressure.
In the technical scheme, in the step (2), the feeding mass space velocity of the oxidation product is 0.1-5.0h -1 。
In the above technical scheme, in the step (2), the functional membrane has catalysis and dehydration effects, and is any one of ceramic materials, diatomite materials, ZSM-5, SAPO-34 or zeolite molecular sieves.
In the above technical scheme, in the step (2), the extractant is any one of pure benzene, aromatic hydrocarbon, alkane with carbon number more than 4 and cycloalkane with carbon number more than 4, or a mixture of two or more of them mixed in any proportion.
In the technical scheme, in the step (2), the dosage of the extractant is 1.0-10.0 times of the mass of the trioxymethylene aqueous solution, and the feeding mass airspeed is as follows: 0.1-10.0h -1 。
In the above technical scheme, in the step (2), the conditions for the extraction catalytic reaction tower to perform polymerization reaction are as follows: the temperature of the tower top is 50-90 ℃, the pressure is 0.1-0.5MPa, the temperature of the tower bottom is 60-150 ℃ and the pressure is 0.1-1.0MPa.
In the above technical scheme, in the step (2), when the water in the trioxymethylene aqueous solution is removed from the extraction catalytic reaction tower, the shell side is controlled to be negative pressure-0.09-0.2 Mpa.
In the above technical scheme, in the step (3), the operation conditions of the extraction separation tower are as follows: overhead temperature: 70-100 ℃; bottom temperature: 100-150 ℃; operating pressure: 0.1-1.0Mpa.
In the above technical scheme, in the step (3), the reflux ratio is 0.1-2.0.
In the technical scheme, in the step (4), the mass ratio of methylal (M1) To trioxymethylene liquid (To) is 1-10:1, and the temperature during mixing is 20-70 ℃.
In the technical scheme, in the step (5), when the mixture enters the multi-stage fixed bed reactor, the space velocity of the feeding mass is 0.1-2.0h -1 。
In the above technical scheme, in step (5), the reaction conditions of the multistage fixed bed reactor are: the feeding temperature is 30-120 ℃ and the pressure is 0-1.0MPa.
In the above technical scheme, in the step (5), the catalyst B is a strong acid resin catalyst, a high temperature resistant strong acid resin catalyst, and a super acid resin catalyst; preferably spherical or beaded high-temperature resistant strong-acid resin catalyst or a module catalyst with the catalyst active ingredients of strong-acid resin catalyst and high-temperature resistant super-acid resin catalyst; wherein the modular catalyst is constructed as in patent 201620189729.2.
In the above technical scheme, in step (6), the operation conditions of the fractionating tower are as follows: overhead temperature: 30-110 ℃; bottom temperature: 100-180 ℃; operating pressure: 0.01-1.5Mpa.
In the above technical scheme, in the step (6), the reflux ratio is 0.1-2.0.
The technical scheme of the invention has the advantages that: under the synergistic effect of extraction, dehydration and catalysis of a functional membrane component, the product obtained by mixing methylal and air is subjected to extraction, dehydration and catalysis synergistic coupling technology to produce high-purity trioxymethylene so as to produce a DMMn product, and the existing method overcomes the defects that: the water absorption technology, the concentration technology, the sulfuric acid catalysis technology and the extraction drying technology have the defects and drawbacks, so that a process is mild in condition, short in process flow, small in investment and quick in effect; high efficiency, low consumption, cleanness and environmental protection, and has a plurality of advantages.
Drawings
Fig. 1 is: the flow chart of the method for synthesizing trioxymethylene and DMMn by the multifunctional film in the invention;
fig. 2 is: the overall structure of the device for synthesizing trioxymethylene and DMMn by the multifunctional film is schematically shown;
fig. 3 is: the schematic structure of the extraction catalytic reaction tower in fig. 2;
fig. 4 is: FIG. 3 is a schematic cross-sectional structural view of a packing assembly of an extractive catalytic reactor;
fig. 5 is: FIG. 3 is a schematic vertical section of a single column in the extractive catalytic reactor;
fig. 6 is: schematic drawing of a thickness section structure of a tube array functional tube of the tubular functional membrane assembly;
Fig. 7 is: schematic structural diagram of a longitudinal section of the catalytic reaction tower;
wherein: 1 is a methylal oxidation reactor; 2 is an extraction catalytic reaction tower, 20 is a foam remover, 211 is an extractant feed port 2D,212 is an exhaust port 2C,213 is a feed port 2A, 214 is a discharge port 2B,215 is a dehydration port 2E,23 is a filler component, 251 is a tube array, 252 is a small hole, 253 is a functional tube, 254 is a filler, 255 is a functional film, 26 is a redistributor, 27 is a tube plate, 28 is a distributor, and 50-is a downcomer; 4 is a stripping tower, 5 is a waste heat boiler, 6 is a heat exchanger, 7 is a condenser I,8 is a condensing tank I,9 is a reflux pump I,10 is a reboiler I,11 is a reboiler II,12 is a multistage fixed bed reactor, 13 is a fractionating tower, 14 is a mixer, 15 is a condenser II,16 is a condensing tank II,17 is a reflux pump II, and 3 is a reboiler III.
Detailed Description
The following detailed description of the technical scheme of the present invention is provided, but the present invention is not limited to the following descriptions:
the invention firstly provides a multifunctional membrane synthesized trioxymethylene and DMM 3-8 Comprises a heat exchanger 6 and a methylal oxidation reactor which are connected in sequence1. The method comprises the steps of (1) an extraction catalytic reaction tower 2, an extraction separation tower 4, a mixer 14, a multi-stage fixed bed reactor 12 and a fractionating tower 13, wherein air and methylal firstly enter a heat exchanger shell side to be heated, then enter a methylal oxidation reactor to be subjected to oxidation reaction, an oxidation product with high temperature is obtained by the oxidation reaction, enters a heat exchanger tube side to exchange heat to obtain a reduced-temperature oxidation product, the reduced-temperature oxidation product enters the extraction catalytic reaction tower to be subjected to polymerization reaction, the polymerization product is extracted and separated to obtain a product trioxymethylene, the trioxymethylene is mixed with methylal in the mixer and then enters the multi-stage fixed bed reactor to be subjected to reaction to synthesize DMMn, and the reaction product DMMn is fractionated to obtain a finished product DMM 3-8 The method comprises the steps of carrying out a first treatment on the surface of the As shown in fig. 2-7:
the heat exchanger 6 is a tube type heat exchanger, a cold material inlet 6A is arranged above the side wall of the shell side, a hot material outlet 6B is arranged below the side wall of the shell side, a feed inlet 6D is arranged at the bottom of the tube side, and a discharge outlet 6C is arranged at the top of the tube side; wherein: the cold material inlet 6A is hot in connection with a device capable of providing air and/or methylal;
the methylal oxidation reactor, the top be equipped with feed inlet 1A, the bottom is equipped with discharge gate 1B, the top of lateral wall is equipped with import 1D, the below is equipped with export 1C, wherein: the feed inlet 1A is connected with a hot material outlet 6B of the heat exchanger; the discharge port 1B is connected with a feed port 6D of the heat exchanger; a waste heat boiler 5 is arranged between the inlet 1D and the outlet 1C, the outlet 1C is connected with the inlet of the waste heat boiler, the inlet 1D is connected with the outlet of the waste heat boiler, and the waste heat boiler provides heat for oxidation reaction;
the extraction catalytic reaction tower is provided with an exhaust port 2C at the top, a discharge port 2B at the bottom, a feed port 2A at the lower part of the side wall, an extractant feed port 2D at the upper part of the side wall, and a water removal port 2E at the middle lower part of the side wall; wherein: the feed inlet 2A is connected with the discharge outlet 6C of the heat exchanger; the extractant charging port 2D is connected with a device capable of providing extractant; the exhaust port 2C is divided into two paths, one path is connected with a cold substance inlet 6A of the heat exchanger so as to return air and recycle the air, and the other path is directly connected with an exhaust gas treatment system and is used for exhausting gas after treatment; the dewatering port 2E is connected with a sewage treatment system, and the dewatered water enters the sewage treatment system for treatment.
The top of the extraction separation tower is provided with a gas phase outlet 4B, the bottom of the extraction separation tower is provided with a discharge outlet 4D, a feed inlet 4A is arranged above the side wall, and a return port 4C is arranged above the other side wall; wherein: the feed inlet 4A is connected with the discharge outlet 2B of the extraction catalytic reaction tower; the gas phase outlet 4B is sequentially connected with a condenser I7, a condensing tank I8 and a reflux pump I9; the outlet of the reflux pump I is divided into two paths, one path is connected with the reflux port 4C, and the other path is connected with the extractant charging port 2D of the extraction catalytic tower so as to recycle the extractant;
the mixer is provided with a feed inlet 14A, a discharge outlet 14C and a methylal inlet 14B; wherein: the feed inlet 14A is connected with the discharge outlet 4D of the extraction and separation tower; the methylal inlet 14B is connected to a device capable of providing methylal;
the top of the multistage fixed bed reactor is provided with a feeding reflux port 12A, the bottom of the multistage fixed bed reactor is provided with a discharge port 12C, and the side wall of the multistage fixed bed reactor is provided with a feeding port 12B; wherein: the feed inlet 12B is connected with the discharge outlet 14C of the mixer; the feeding return port 12A is divided into two paths, wherein one path is also connected with the discharge port 14C of the mixer, and the mixed materials are fed from the top and the side wall simultaneously, so that the full chemical reaction can be carried out in the fixed bed reactors of different sections in the multi-section fixed bed reactor;
The finished product fractionating tower, the top be equipped with gaseous phase export 13C, the bottom is equipped with discharge gate 13D, the lateral wall top is equipped with return port 13B, the middle part is equipped with feed inlet 13A, wherein: the feed inlet 13A is connected with the discharge outlet 12C of the multistage fixed bed reactor; the gas phase outlet 13C is sequentially connected with a condenser II 15, a condensing tank II 16 and a reflux pump II 17; the outlet of the reflux pump II is divided into two paths, one path is connected with a reflux port 13B, and the other path is connected with the other path of the feed reflux port 12A of the multi-section fixed bed reactor; discharge port 13D and collecting or receiving finished DMM 3-8 Is connected with the device of the device.
In the utility model, the methylal oxidation reactor is filled with a catalyst A, wherein the catalyst A is an iron-molybdenum catalyst, and the iron-molybdenum catalyst is preferably the same as the type and the proportion of the active components or the active catalysts of the catalysts used in the utility model patent CN201710307041.9, the utility model patent CN201720485329.0 or the utility model patent CN 201720483709.0.
In the present utility model, the methylal oxidation reactor has the same structure as the methanol oxidation device in the utility model patent CN201720483709.0, the feed inlet 1A and the discharge outlet 1B are identical to the feed inlet and the discharge outlet of the methanol oxidation device, and the inlet 1D and the outlet 1C are formed above and below the side wall of the casing of the methanol oxidation device:
The main body of the oxidation reactor is the oxidation reactor, the oxidation reactor is composed of a shell and an internal component, the internal component is sequentially provided with a stainless steel wire mesh, an upper partition plate, a tube array and a lower partition plate from top to bottom, and the top of the shell is provided with a feed inlet, and the bottom of the shell is provided with a discharge outlet;
in the oxidation reactor, a stainless steel wire mesh with a dispersing function is arranged at the upper part, an upper baffle plate is arranged at the lower part of the stainless steel wire mesh, a plurality of tube arrays are welded below the upper baffle plate, and the tail ends of the tube arrays are welded with a lower baffle plate;
the tubes are distributed and arranged in a regular triangle; (when the oxidation reactor is an industrial device, the tube arrays are arranged in a regular triangle, but when the small-sized experiment is carried out, the oxidation reactor is a small-sized experiment device, and the tube arrays are single);
the tube array is internally filled with a plurality of cylindrical packed catalysts;
the outer diameter of the packed catalyst is equal to the inner diameter of the tube array of the methanol oxidation reactor;
the inner diameter of each tube row is more than or equal to 25mm, preferably more than or equal to 60mm, more preferably more than or equal to 80mm, and the length of each tube row is more than or equal to 1500mm, preferably more than or equal to 2000mm, more preferably more than or equal to 3000mm;
the number N of packed catalysts in each tube array is more than or equal to 5, preferably more than or equal to 10;
The height of the packed catalyst is more than or equal to 100mm, preferably more than or equal to 200mm, and more preferably more than or equal to 300mm;
the packed catalyst included stainless steel planar wire mesh, stainless steel corrugated wire mesh, and catalyst active ingredient (i.e., catalyst a of the present invention): the catalyst active ingredients are uniformly distributed on the stainless steel plane wire mesh, and after the stainless steel corrugated wire mesh is tiled and overlapped with the stainless steel corrugated wire mesh to cover the catalyst active ingredients, the edge is closed, and one end is taken as an axle center to be rolled into a solid cylindrical packed catalyst;
the active component of the catalyst is spherical, bar-shaped, cylindrical or cube-shaped; the diameter of the sphere, the length, the width and the height of the bar, the diameter and the height of the cylinder and the side length of the cube are all required to be larger than the mesh side length of the stainless steel plane silk screen and the mesh side length of the stainless steel corrugated silk screen; the mesh side length of the stainless steel plane silk screen and the mesh side length of the stainless steel corrugated silk screen are less than 2mm;
the catalyst active ingredients are compounded by the following components in percentage by mass: m is M O O 3 60-78％、Fe 2 O 3 20-39%, and 0.1-2.0% of other element oxides; the other element oxides are any one of oxides of elements in IIIA, IV A or VIII groups or a mixture formed by mixing oxides of two elements according to the mass ratio of 0.1-1:1; the other element oxide is preferably Al 2 O 3 ；
The packed catalysts are placed from top to bottom when being packed in a tube array, and the staggered angle of two adjacent packed catalysts is more than or equal to 10 degrees; the staggered angle is an included angle of a horizontal circular line of the edge line when adjacent packed catalysts are rolled;
the packed catalysts are characterized in that the distribution of the catalyst active components on each packed catalyst is uniform, namely the distribution of the active catalyst on each section of one packed catalyst is uniform; when a plurality of packed catalysts are packed in a tube array, the catalyst active components in the packed catalysts are uniformly increased along the axial direction from top to bottom, the catalyst active components in the packed catalysts at the top are the least, and the catalyst active components in the packed catalysts at the bottom are the most;
the catalyst active ingredient in the packed catalyst is uniformly increased along the axial direction from top to bottom, and the increasing amplitude is calculated according to the following formula:
k= (an+1-an)/an, K is a constant and 0< K <1;
an is the mass of the active catalyst of the n-th layer;
an+1 is the mass of the active catalyst of the n+1 layer, i.e., the mass of the active catalyst of the layer below the n layer;
n=1, 2,3,4,5, 6..natural positive integer of n;
when k=1, the active catalyst in the whole tube array is uniformly distributed; when 0< k <1, the amount of active catalyst contained in each section gradually increases along the tube array axis downward, i.e., the more the active catalyst is contained in each section toward the lower portion of the reactor tube array, and the more uniformly increases.
In the present invention, the extraction catalytic reaction tower 2, the internals include: demister 20, distributor 28, packing assembly 23: the uppermost end in the extraction catalytic reaction tower is provided with a foam remover and a distributor below the foam remover; the distributor is filled with a plurality of sections of filler assemblies 23, and a redistributor 26 is arranged between each section of filler assembly; the filler assembly is communicated with the adjacent distributor and the redistributor;
the packing assembly is a multifunctional membrane assembly and comprises a plurality of vertically arranged up-and-down through tubes 251 which are arranged into a tube bed and fixed by a tube plate 27, a plurality of small holes 252 are formed in the whole body of the tube, sintered up-and-down through functional tubes 253 are inserted into the tube, functional membranes 255 are formed by composite sintering of the inner surfaces of the functional tubes, and the functional tubes are internally filled with packing 254;
sealing materials are arranged at the upper end and the lower end of a gap between the tube array 251 and the functional tube 253 for sealing and fixing; the packing assembly is communicated with the adjacent distributor 28 and the redistributor 26 through the functional pipe 253 to form a reaction channel; the filler assembly 23, the redistributor 26 and the side wall of the reaction tower form a dehydration runner, and tube plates of each section are communicated through a downcomer;
The top of the reaction tower is provided with the exhaust port 2C 212, the bottom of the reaction tower is provided with the discharge port 2B 214, the side wall of the bottom of the reaction tower is provided with the feed port 2A 213, the lowest filler component 23 is provided with the dehydration port 2E 215 on the side wall of the reaction tower, and the uppermost distributor of the reaction tower is communicated with the extractant feed port 2D 211 arranged on the side wall of the reaction tower;
the bottom layer of tube plates 27 are closed water receiving plates, the tube plates 27 above the bottom layer are communicated through downcomers 50, the top layer of tube plates 27 are provided with vacuumizing ports and are connected with an external vacuumizing system, and all spaces outside the tube arrays 251 and communicated by the downcomers 50 are vacuumized;
diameter of the small hole 2521-50mm;
the functional pipe 253 is made of ceramic materials through sintering; the functional membrane 255 is made by composite firing of any one of ceramic material, diatomite material, ZSM-5, SAPO-34 or zeolite molecular sieve and the inner surface of the functional tube 253;
the filler 254 is a cylindrical regular filler of stainless steel corrugated wire mesh;
the foam remover 20, the distributor 28 and the redistributor 26 are all internally composed of stainless steel corrugated wire meshes; the distributor 28 and the redistributor 26 are respectively provided with a plurality of flow guide ports communicated with the functional pipes 253;
The sealing material is a polytetrafluoroethylene sealing gasket or a metal winding gasket or an anti-corrosion rubber gasket; the fixing mode of the sealing material is selected from various conventional fixing modes, and the sealing material can be fastened and fixed by using a bolt fastener;
the packing assembly 23 is filled in sections, the filling amount is N sections, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3m; each section of filling functional pipe 253 is M, and M is more than or equal to 1 and less than or equal to 5000; each pipe diameter is D, and D is more than or equal to 5 and less than or equal to 200cm;
the extraction catalytic reaction tower 2 is characterized in that the extractant added from the extractant feed inlet 2D is any one of pure benzene, aromatic hydrocarbon, alkane with carbon number more than 4 and cycloalkane with carbon number more than 4, or a mixture formed by mixing two or more than two of the above components in any proportion;
in the invention, the inside of the tube array 251 is communicated with the distributor 28 and the redistributor 26 to form vertical gas phase and extraction channels, and a water channel is formed between the outside of the tube array 251 and the inner wall of the reaction tower 2; after entering from an extractant feed port 2D 211 at the top of the column, the extractant flows into the column tubes 251 of the packing assembly 23 through the distributor 28 and is dispersed by the packing 254 in the column tubes 251; after the oxidation gas phase enters through a feed port 2A 213 at the bottom of the tower, the oxidation gas phase enters into the tube array 251 through the lowest redistributor 26 to rise, is extracted by the extraction liquid in the filler 254 in the functional membrane 255 and is dehydrated with the functional membrane 255, water seeps out from the tube array 251 from the small holes 252 due to osmotic pressure, and is gathered downwards on the lowest tube plate 27, flows out through the dehydration port 2E 215, and unreacted gas continuously rises and reacts repeatedly; water from the upper reaction flows up from the tube plate 27 with the downcomer to the bottom-most closed tube plate 27; the gas is extracted and dehydrated for multiple times, and is refined again by the demister 20 at the top of the tower and then discharged from the exhaust port 2C 212. The reacted extract phase is discharged from the discharge port 2B 214.
In the invention, the extraction separation tower 4 is internally provided with tower internals, wherein the tower internals are any one of structured packing and tower plates; if the packing is structured packing, the number of the packing sections is N, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3 meters; if the plate is a column plate, the number of theoretical plates is M, and M is less than or equal to 1 and less than or equal to 100; a reboiler I10 is mounted below the side walls.
In the invention, the fractionating tower (13) is internally provided with tower internals, wherein the tower internals are any one of structured packing and tower plates; if the packing is structured packing, the number of the packing sections is N, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3 meters; if the plate is a column plate, the number of theoretical plates is M, and M is less than or equal to 1 and less than or equal to 100; a reboiler III 3 is mounted below the side wall.
In the present invention, the number of layers N of the fixed bed in the multistage fixed bed reactor 12 is: 1-10, each layer of fixed bed is filled with a catalyst B; in the multistage fixed bed reactor, a reboiler II 18 is arranged below the side wall.
In the invention, the catalyst B is a strong acid resin catalyst, a high temperature resistant strong acid resin catalyst and a super acid resin catalyst; preferably spherical or beaded high-temperature resistant strong-acid resin catalyst or a module catalyst with the catalyst active ingredients of strong-acid resin catalyst and high-temperature resistant super-acid resin catalyst;
The structure of the module catalyst is the same as that of a device for producing polymethoxy dimethyl ether DMM3-5 in patent 201620189729.2: the module catalyst comprises an active catalyst, a wire mesh and a wire corrugated plate: the module catalyst is formed by arranging the wire mesh and the wire mesh corrugated plates in parallel at intervals, the catalyst particles are contained between the two wire mesh plates to form a catalyst layer, and the catalyst particles in the catalyst layer are arranged by the wire mesh corrugated plates at intervals; the catalyst layers in the module catalyst are arranged at intervals; the module catalyst is fixed on the periphery by metal wires; the outer contour of the module catalyst is wrapped and fixed by the wire mesh to form a geometric shape, and the geometric shape is a cube and a cylinder (in the embodiment, the cylinders are all the same); one or two layers (one layer in the embodiment) of metal wire mesh corrugated plates are arranged between the metal wire meshes; the catalyst layer is arranged at intervals by one or two layers (one layer in the embodiment) of metal wire mesh corrugated plates; the catalyst layer is formed by spacing one or two layers (one layer in the embodiment) of wire mesh corrugated plates between two layers of wire mesh and is internally filled with the catalyst particles (namely the catalyst B of the invention); the catalyst layers form liquid phase channels, and metal wire corrugated plate layers between adjacent catalyst layers form gas phase channels; the wire mesh and the wire mesh corrugated plate are made of stainless steel materials (or replaced by stainless steel plates with holes); the wire mesh and the wire mesh corrugated plate are vertically arranged up and down; the catalyst layer is provided with a reinforced outer wall, and the double layers of the metal wire mesh and the stainless steel belt pore corrugated plate are used as the outer wall of the catalyst layer; the catalytic section is internally filled with the module catalysts, a feeding space or a space for installing a feeding distributor is reserved up and down, a plurality of module catalysts are stacked up and down, and the gas phase channel and the liquid phase channel are vertically arranged up and down; in the catalytic section, the gas phase channels and the liquid phase channels of the module catalysts of adjacent layers are arranged oppositely.
In the invention, the waste heat boiler, the heat exchanger (tube type), the condenser I, the condensing tank I, the reflux pump I, the reboiler I, the condenser II, the condensing tank II, the reflux pump II, the reboiler II and the reboiler III are all products sold in the field or products with corresponding functions.
The invention also provides a multifunctional membrane synthesis trioxymethylene and a DMM 3-8 Comprising the steps of:
(1) Oxidation reaction: preheating methylal and air to 100-200 ℃, carrying out oxidation reaction under the catalysis of a catalyst A, obtaining an oxidation product with higher temperature after the oxidation reaction, and obtaining an oxidation product with reduced temperature after heat exchange;
(2) Polymerization reaction: the oxidation product with reduced temperature is polymerized under the catalysis of the functional film material to generate trioxymethylene aqueous solution; extracting the trioxymethylene aqueous solution by an extracting agent to form an extracting solution containing trioxymethylene, wherein one part of reaction residual gas is exhausted, and the other part of reaction residual gas is returned to the step (1) for recycling;
(3) Extraction and fractionation: fractionating the extract containing trioxymethylene obtained in the step (3) under a heating state to obtain a gas phase and a liquid phase; the gas phase is an extractant, a liquid phase extractant is obtained after condensation, a part of the liquid phase extractant flows back, and the other part returns to the step (2) for recycling; the liquid phase is high-purity trioxymethylene liquid;
(4) Mixing: fully mixing the high-purity trioxymethylene liquid (To) obtained in the step (3) with methylal (M1) To obtain a mixture, and then carrying out a reaction for synthesizing DMMn;
(5) Synthesizing DMMn: the mixture obtained in the step (4) reacts under the catalysis of the catalyst B to generate a DMMn product;
(6) And (3) product fractionation: fractionating the DMMn product obtained in the step (5) under a heating state to obtain a gas phase and a liquid phase; the gas phase is excessive methylal, part of the methylal is refluxed after condensation, and the other part of methylal is returned to the step (4) for recycling; the liquid phase is the product DMM 3-8 。
The process according to the invention is illustrated below with reference to specific examples:
example 1:
a method for synthesizing trioxymethylene and DMMn by using a multifunctional membrane comprises the following steps:
(1) Oxidation reaction: 7.6g of methylal and 7.76L of air are preheated to 100-150 ℃ by a preheater 6 and then enter a methylal oxidation reactor from a feed inlet 1A, and the feeding mass airspeed is 0.15h -1 The oxidation reaction is carried out under the catalysis of an iron-molybdenum catalyst in the methylal oxidation reactor, and the reaction conditions in the methylal oxidation reactor are as follows: temperature: 300 ℃ and under normal pressure; 12L of oxidation product was obtained; the temperature of an oxidation product at a discharge port 1B of the methanol oxidation reactor is 260-350 ℃, the oxidation product is subjected to heat exchange by a heat exchanger (6), and enters an extraction dehydration catalytic reaction tower 2 from a feed port 2A and a redistributor 26 after the temperature is reduced to 65-105 ℃;
In this example, the iron molybdenum catalyst is the same as in example 1 of patent CN 201720483709.0: m is M O O 3 74％、Fe 2 O 3 25％、Al 2 O 3 1.0%.
In the methylal oxidation reactor used in the embodiment, the tubes are single, the inner diameter of each tube is 40mm, the length of each tube is 2000mm, 6 packed catalysts are arranged in each tube, and the staggered angle of two adjacent packed catalysts is 15 degrees; the mass of the active ingredient in the layer 1 (i.e., uppermost) packed catalyst was 10g, and the mass of the active ingredient in the layer 2 packed catalyst was 12g, i.e., k=0.2.
(2) Polymerization reaction: 12L of the oxidation product obtained in the step (1) is fed at a space velocity of 0.2h -1 Under the catalysis of the functional film 255 in the extraction catalytic reaction tower, the polymerization reaction is carried out under the conditions of the tower top temperature of 70-90 ℃, the tower bottom temperature of 0.1MPa, the tower bottom temperature of 80-100 ℃ and the tower bottom temperature of 0.2MPa, and 10.8g of trioxymethylene aqueous solution is generated; the oxidation products which are not fully reacted continue to go upward, and the generated trioxymethylene aqueous solution also goes upward along with the airflow of the oxidation products, so that 3 times of the pure benzene (27 g of the corresponding extract) which is extracted from top to bottom is extracted, and the feeding airspeed is 0.6h -1 ) The density of the extracted and absorbed trioxymethylene is increased and gradually goes down to the bottom of the tower after the extractant absorbs trioxymethylene The method comprises the steps of carrying out a first treatment on the surface of the Simultaneously, under the dehydration action of the functional film, the water in the trioxymethylene aqueous solution is gradually removed so that the concentration of the trioxymethylene is higher and the trioxymethylene also gradually descends, and the concentration of the trioxymethylene in the upward oxidation product gas flow is gradually reduced until the concentration is zero; the upward gas-phase oxidation product also contains gas-phase formaldehyde, and the gas-phase formaldehyde can be extracted by the extractant from top to bottom and absorbed, so that a liquid-phase extractant containing formaldehyde is generated, the density of the extractant containing formaldehyde is increased, the extractant gradually descends in the tower, and the upward formaldehyde, the gas-phase formaldehyde and the downward formaldehyde in the liquid phase continue to undergo polymerization reaction under the catalysis of the functional film, so that the reaction of formaldehyde in the oxidation product is complete; the residual gas of the reaction can continuously go upward to the demister in the tower, the demister thoroughly intercepts the extractant carried in the demister, one part of the residual gas is processed and exhausted to the exhaust port 2C, and the other part of the residual gas is led into the heat exchanger through the cold material inlet 6A and returns to the oxidation reactor for recycling after being heated together with methylal according to the operation in the step (1); under the dehydration action of the functional film, the water in the trioxymethylene aqueous solution is gradually removed, the pressures of the inner side and the outer side of the functional pipe are different, the inner side is positive, and relative to the outside, osmotic pressure exists, so that the removed water is beneficial to exuding from the functional pipe and being discharged through small holes on a tube array, the shell side of the extraction catalytic reaction tower is controlled to be negative pressure (the operating pressure is minus 0.03 Mpa), and under the dual action of the functional film and the negative pressure, 1.8 g of water obtained by removal is discharged from a dehydration port 2E; 9.0 g of trioxymethylene is extracted by 27 g (22.4 g is added with 5.4 g for reflux of the fractionating tower) of pure benzene, and then sequentially flows through a discharge hole 2B and a feed hole 4A and enters the extraction and separation tower 4;
In this embodiment, the design of the extraction dehydration catalytic reaction tower is as follows: the multifunctional membrane component in the tower is filled according to sections, the filling amount is 3 sections, and the height of each section is 1m; each section is filled with 5 multifunctional membrane components; each pipe diameter is 5cm, a redistributor is arranged between each two sections, a foam remover is arranged at the uppermost end of the tower, namely above the extractant inlet, and each pipe is filled with a filler (stainless steel corrugated wire mesh structured filler with cylindrical geometry); the demister and redistributor are made of stainless steel corrugated wire mesh; the small holes with the diameter of 3mm are formed on the whole tube array, so that the water which is separated out can be conveniently discharged out of the system in time.
In this embodiment, the functional membrane is made of ZSM-5, and its molecular inner pore is 1-5×10 -1 nm, the functional tube 253 is fired from ceramic 75 into a ceramic tube, wherein Al 2 O 3 The content is controlled to be more than 75%, the rest components are conventional, and the ceramic 75 is an existing material and can be purchased from outside; the tube array is a metal tube.
(3) Extraction and fractionation: after the extract phase obtained in the step (2) enters the extraction separation tower, fractionating under the heating effect of a reboiler I of the extraction separation tower, wherein the reaction conditions are as follows: overhead temperature: 60-90 ℃; bottom temperature: 100-150 ℃; operating pressure: 0.1-0.50Mpa to obtain gas phase and liquid phase; the gas phase is an extractant, the gas phase is discharged from a gas phase outlet 4B and enters a condenser I7 for condensation, 22.4g of liquid extract obtained after condensation sequentially flows through a condensation tank I8 and a reflux pump I9 and is divided into two paths, one path of liquid extract flows back to 5.4 g of a fractionating tower (reflux ratio is 0.2) from a reflux port 4C, and the other path of liquid extract returns to the extraction dehydration catalytic tower from an extractant feeding port 2D for recycling; the liquid phase is the finished product of the product trioxymethylene, 9.0g of refined high-purity trioxymethylene is discharged from a discharge hole 4D at the bottom of the tower and enters a mixer 14.
In the embodiment, the extraction and separation tower is internally provided with tower internals, the tower internals are stainless steel corrugated plate structured packing, the number of filling sections is 2, and the height of each section is 2 meters.
(4) Mixing: introducing high-purity trioxymethylene liquid into the mixer 14 from the feed inlet 14A, and simultaneously introducing 3 times of 27 g of methylal into the mixer from the methylal inlet 14B, wherein the temperature is 25-35 ℃ during mixing; the trioxymethylene and the methylal are fully mixed in a mixer to obtain a mixture, the mixture is led out from a discharge hole 14C, and the mixture is led into a multistage fixed bed reactor through a feed return 12A at the top and a feed hole 12B at the side wall;
(5) Synthesizing DMMn: the feed mass space velocity of the mixture was 0.5h -1 In a multistage fixed bed reactor, a D006 resin catalyst is filled, DMMn is synthesized under the conditions that the reaction temperature is 60-70 ℃ and the pressure is 0.15-0.25Mpa, and the DMMn is led out through a 12C outlet of a discharge holeAnd is introduced into the fractionating tower 13 through the feed inlet 13A;
in this embodiment, the number of layers N of the fixed bed in the multistage fixed bed reactor is 4, each layer is filled with a module catalyst, and the active component of the catalyst in the module catalyst is D006 resin catalyst manufactured by kei environmental protection technologies, inc.
(6) And (3) product fractionation: after the DMMn product obtained in step (5) enters the fractionating tower 13, fractionation is performed in a heated state of the reboiler III under the following fractionation conditions: overhead temperature: 102 ℃; bottom temperature: 150 ℃; operating pressure: 0.6Mpa; the gas phase at the top of the tower is discharged from a gas phase outlet 13C and sequentially passes through a condenser II 15, a condensing tank II 16 and a reflux pump II 17 to be divided into two paths: one path is refluxed to the finished product fractionating tower 13 through a reflux port 13B, the reflux ratio is 0.3, namely, the reflux quantity is 8.1 g, the other path is the residual quantity of methylal after reaction is refluxed to a feed reflux port 12A for continuous reaction, 16.2 g of DMMn3-5 finished product is obtained at the bottom of the tower, the yield of the finished product reaches more than 97%, and the purity is nearly 100%.
Example 2:
a method for synthesizing trioxymethylene and DMMn by using a multifunctional film is the same as that of example 1, except that the oxidation feeding amount of methylal is increased by 1 time, the yield of finished products is still kept at about 97%, and the purity is nearly 100%.
The foregoing examples are merely illustrative of the technical concept and technical features of the present invention, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made according to the essence of the present invention should be included in the scope of the present invention.
Claims (9)
1. Multifunctional membrane synthesis trioxymethylene and DMM 3-8 Is characterized by comprising the following steps:
(I) Oxidation reaction: the methylal and air enter the shell pass of the heat exchanger from the cold material inlet 6A for preheating, are led out from the hot material outlet 6B after being preheated to 100-200 ℃, are led into the methylal oxidation reactor from the feed inlet 1A, and are subjected to oxidation reaction under the catalysis of the catalyst A in the methylal oxidation reactor; the temperature of the oxidation product at the discharge port 1B of the methylal oxidation reactor is 200-450 ℃; the oxidation product with the temperature of 200-450 ℃ is led out from a discharge port 1B and is led into a tube side of a heat exchanger from a feed port 6D for heat exchange, and is led out from a discharge port 6C and is led into an extraction catalytic reaction tower from a feed port 2A after the temperature is reduced to 50-100 ℃; the catalyst A is an iron-molybdenum catalyst;
(II) polymerization: the oxidation product in the step (I) is in a gas phase, and is led into a tube side of a tubular functional membrane component in the extraction catalytic reaction tower through a feed inlet 2A, and is subjected to polymerization reaction under the catalysis of a functional membrane material of the tubular functional membrane component to generate trioxymethylene aqueous solution; the oxidation products which do not react completely continue to ascend, and the generated trioxymethylene aqueous solution also continues to ascend along with the airflow of the oxidation products, so that the trioxymethylene aqueous solution is extracted and absorbed by the extractant added from the 2D extractant charging port from top to bottom, and the density of the extractant increases after absorbing the trioxymethylene and gradually descends to the bottom of the tower; simultaneously, under the dehydration action of the functional film material, the water in the trioxymethylene aqueous solution is gradually removed so that the concentration of the trioxymethylene is higher and the trioxymethylene also gradually descends, and the concentration of the trioxymethylene in the upward oxidation product gas flow is gradually reduced until the concentration is zero; the upward gas-phase oxidation product also contains gas-phase formaldehyde, and the gas-phase formaldehyde can be extracted by the extractant from top to bottom and absorbed, so that a liquid-phase extractant containing formaldehyde is generated, the density of the extractant containing formaldehyde is increased, the extractant gradually descends in the tower, and the upward formaldehyde, the gas-phase formaldehyde and the downward formaldehyde in the liquid phase can continue to undergo polymerization reaction under the catalysis of the functional membrane material of the tubular functional membrane component, so that the reaction is repeated until the formaldehyde in the oxidation product is thoroughly reacted; the residual gas of the reaction can continuously go upward to the demister in the tower, the demister thoroughly intercepts the extractant carried in the demister, one part of the residual gas is processed and exhausted to the exhaust port 2C, and the other part of the residual gas is led into the heat exchanger through the cold material inlet 6A and is returned to the oxidation reactor for recycling after being heated together with methylal according to the operation in the step (I); under the dehydration action of the functional film material, the water in the trioxymethylene aqueous solution is gradually removed, and meanwhile, the shell side of the extraction catalytic reaction tower is controlled to be negative pressure, and under the dual actions of the functional material and the negative pressure, the removed water is discharged from a dehydration port 2E; the extracting agent containing the trioxymethylene is led out from a discharge hole 2B and is led into a stripping tower (4) from a feed hole 4A;
The multifunctional membrane component comprises a plurality of vertically arranged up-and-down through tubes (251) which are arranged in a tube bed and fixed by a tube plate (27), wherein a plurality of small holes (252) are formed in the whole body of the tubes (251), and sintered up-and-down through functional tubes (253) are inserted into the tubes (251); the functional pipe (253) is made of ceramic materials through sintering, the functional film is made of functional film materials and the inner surface of the functional pipe 253 through composite firing, and the functional film materials are ZSM-5;
(III) extractive fractionation: after the extracting agent containing the trioxymethylene obtained in the step (II) enters the extraction separation tower (4), fractionating the extracting agent in a heating state of a reboiler I (10) of the fractionating tower to obtain a gas phase and a liquid phase; the gas phase is an extractant, the gas phase is discharged from a gas phase outlet 4B and enters a condenser I (7) for condensation, the liquid extractant obtained by condensation sequentially flows through a condensing tank I (8) and a reflux pump I (9) and is divided into two paths, one path of liquid extractant flows back into the extraction separation tower from a reflux port 4C, and the other path of liquid extractant flows back into the extraction catalytic reaction tower from an extractant charging port 2D for recycling; the liquid phase is high-purity trioxymethylene liquid, is led out from a discharge hole 4D at the bottom of the tower and is led into a mixer (14) from a feed hole 14A;
(IV) mixing: introducing a high purity trioxymethylene liquid from a feed port 14A into a mixer 14 while introducing methylal from a methylal inlet 14B into the mixer; the trioxymethylene and the methylal are fully mixed in a mixer to obtain a mixture, the mixture is led out from a discharge hole 14C, and the mixture is led into a multi-section fixed bed reactor through a feed return hole 12A at the top and a feed hole 12B at the side wall;
(V) synthetic DMMn: the mixture obtained in the step (IV) enters a multistage fixed bed reactor, and is subjected to condensation reaction under the catalysis of a catalyst B in the reactor to generate DMMn, wherein the DMMn is led out from a discharge hole 12C and is led into a finished product fractionating tower (13) from a feed hole 13A; the catalyst B is a strong acid resin catalyst, a high temperature resistant strong acid resin catalyst and a super acid resin catalyst;
(VI) fractionation of the finished product: after the DMMn obtained in the step (V) enters a fractionating tower (13), fractionating the DMMn in a heating state of a reboiler III (19) to obtain a gas phase and a liquid phase, wherein the gas phase is excessive methylal, and the liquid phase is a product DMM3-8; the gas phase is discharged from a gas phase outlet 13C and enters a condenser II (15) for condensation, methylal obtained by condensation sequentially flows through a condensation tank II (16) and a reflux pump II (17) and is divided into two paths, one path of methylal flows back to the fractionating tower from a reflux port 13B, and the other path of methylal returns to the multistage fixed bed reactor from a feed reflux port 12A for recycling; the product DMM3-8 is discharged from a discharge hole 13D and collected.
2. The process of claim 1, wherein in step (I), the reaction conditions in the methylal oxidation reactor are: the temperature is 200-450 ℃, and the pressure is normal or micro-positive pressure;
in the step (II), the conditions for the extraction catalytic reaction tower to perform polymerization reaction are as follows: the temperature of the tower top is 50-90 ℃, the pressure is 0.1-0.5MPa, the temperature of the tower bottom is 60-150 ℃ and the pressure is 0.1-1.0MPa; when the water in the trioxymethylene aqueous solution is removed, controlling the shell side to be negative pressure of-0.09-0.2 Mpa;
in the step (III), the operation conditions of the extraction tower (4) are as follows: overhead temperature: 70-100 ℃; bottom temperature: 100-150 ℃; operating pressure: 0.1-1.0Mpa; the reflux ratio is 0.1-2.0;
in the step (IV), the mass ratio of methylal to trioxymethylene liquid is 1-10:1, and the temperature during mixing is 20-70 ℃;
in step (V), the reaction conditions of the multistage fixed bed reactor: the feeding temperature is 30-120 ℃ and the pressure is 0-1.0MPa;
in step (VI), the fractionation column (13) is operated under the following conditions: overhead temperature: 30-110 ℃; bottom temperature: 100-180 ℃; operating pressure: 0.01-1.5Mpa; the reflux ratio is 0.1-2.0.
3. The method of claim 1, wherein in step (I), the methylal is mixed with air, and wherein the mass content of oxygen is: 5-20%, and the space velocity of the feeding mass is 0.1-5.0h -1 ；
In the step (II), the oxidation product has a feed mass space velocity of 0.1 to 5.0h -1 The method comprises the steps of carrying out a first treatment on the surface of the The extractant is pure benzene; the dosage of the extractant is 1.0-10.0 times of the mass of the trioxymethylene aqueous solution;
in the step (V), when the mixture enters the multi-stage fixed bed reactor, the feeding mass space velocity is 0.1-2.0h -1 。
4. A multifunctional membrane-synthesized trioxymethylene and DMM as defined in claim 1 3-8 Multifunctional membrane synthesis trioxymethylene and DMM used in the method of (2) 3-8 The device comprises a heat exchanger, a methylal oxidation reactor (1), an extraction catalytic reaction tower (2), an extraction separation tower (4), a mixer (14), a multi-stage fixed bed reactor (12) and a fractionating tower (13), wherein air and methylal firstly enter a heat exchanger shell side to be heated and then enter the methylal oxidation reactor to perform oxidation reaction, oxidation products with high temperature obtained by the oxidation reaction enter the heat exchanger tube side to perform heat exchange to obtain oxidation products with reduced temperature, the oxidation products with reduced temperature enter the extraction catalytic reaction tower to perform polymerization reaction, the products of trioxymethylene are obtained after extraction separation of the polymerization products, the trioxymethylene and methylal are mixed in the mixer and then enter the multi-stage fixed bed reactor to perform reaction to synthesize DMMn, and the DMMn of the reaction products is fractionated to obtain a finished product DMM3-8; the method is characterized in that:
The heat exchanger (6) is a tube type heat exchanger, a cold material inlet 6A is arranged above the side wall of the shell side, a hot material outlet 6B is arranged below the side wall of the shell side, a feed inlet 6D is arranged at the bottom of the tube side, and a discharge outlet 6C is arranged at the top of the tube side; wherein: the cold material inlet 6A is hot in connection with a device capable of providing air and/or methylal;
the methylal oxidation reactor (1), the top be equipped with feed inlet 1A, the bottom is equipped with discharge gate 1B, the top of lateral wall is equipped with import 1D, the below is equipped with export 1C, catalyst A is filled in it, wherein: the feed inlet 1A is connected with a hot material outlet 6B of the heat exchanger (6); the discharge port 1B is connected with a feed port 6D of the heat exchanger; a waste heat boiler (5) is arranged between the inlet 1D and the outlet 1C, the outlet 1C is connected with the inlet of the waste heat boiler, the inlet 1D is connected with the outlet of the waste heat boiler, and the waste heat boiler provides heat for oxidation reaction;
the extraction catalytic reaction tower (2) is provided with an exhaust port 2C (212) at the top, a discharge port 2B (214) at the bottom, a feed inlet 2A (213) at the side wall of the bottom, an extractant feed inlet 2D (211) above, and a water removal port 2E (215) at the middle lower part of the side wall; wherein: the feed inlet 2A is connected with a discharge outlet 6C of the heat exchanger (6); the extractant charging port 2D is connected with a device capable of providing extractant; the exhaust port 2C is divided into two paths, one path is connected with a cold substance inlet 6A of the heat exchanger so as to return air and recycle the air, and the other path is directly connected with an exhaust gas treatment system and is used for exhausting gas after treatment; the dewatering port 2E is connected with a sewage treatment system, and the dewatered water enters the sewage treatment system for treatment;
The extraction separation tower (4) is provided with a gas phase outlet 4B at the top, a discharge outlet 4D at the bottom, a feed inlet 4A above the side wall and a return port 4C above the other side wall; wherein: the feed inlet 4A is connected with the discharge outlet 2B of the extraction catalytic reaction tower; the gas phase outlet 4B is sequentially connected with a condenser I (7), a condensing tank I (8) and a reflux pump I (9); the outlet of the reflux pump I is divided into two paths, one path is connected with the reflux port 4C, and the other path is connected with the extractant charging port 2D of the extraction catalytic tower so as to recycle the extractant; the reboiler I (10) is arranged below the side wall of the extraction tower;
the mixer (14) is provided with a feed inlet 14A, a discharge outlet 14C and a methylal inlet 14B; wherein: the feed inlet 14A is connected with the discharge outlet 4D of the extraction tower; the methylal inlet 14B is connected to a device capable of providing methylal;
the top of the multistage fixed bed reactor (12) is provided with a feeding reflux port 12A, the bottom of the multistage fixed bed reactor is provided with a discharge port 12C, the side wall of the multistage fixed bed reactor is provided with a feeding port 12B, and each layer of fixed bed is filled with a catalyst B; wherein: the feed inlet 12B is connected with the discharge outlet 14C of the mixer; the feeding return port 12A is divided into two paths, wherein one path is also connected with the discharge port 14C of the mixer, and the mixed materials are fed from the top and the side wall simultaneously, so that the full chemical reaction can be carried out in the fixed bed reactors of different sections in the multi-section fixed bed reactor; the reboiler II (11) is arranged below the side wall of the multistage fixed bed reactor;
The top of the finished product fractionating tower (13) is provided with a gas phase outlet 13C, the bottom of the finished product fractionating tower is provided with a discharge outlet 13D, a reflux inlet 13B is arranged above the side wall, a feed inlet 13A is arranged in the middle of the finished product fractionating tower, and a reboiler III (3) is arranged below the side wall; wherein: the feed inlet 13A is connected with the discharge outlet 12C of the multistage fixed bed reactor; the gas phase outlet 13C is sequentially connected with a condenser II (15), a condensing tank II (16) and a reflux pump II (17); the outlet of the reflux pump II (17) is divided into two paths, one path is connected with a reflux port 13B, and the other path is connected with the other path of the feed reflux port 12A of the multi-section fixed bed reactor; the discharge port 13D is connected with a device for collecting or receiving the finished DMM 3-8.
5. The device according to claim 4, wherein the methylal oxidation reactor (1) is characterized in that the main body of the methylal oxidation reactor is an oxidation reactor, the oxidation reactor is composed of a shell and an internal component, the internal component is sequentially provided with a stainless steel wire mesh, an upper partition plate, a tube array and a lower partition plate from top to bottom, the top of the shell is provided with a feed inlet 1A, the bottom is provided with a discharge outlet 1B, and the upper part and the lower part of the side wall of the shell of the equipment for oxidizing methanol are provided with the inlet 1D and the outlet 1C; in the oxidation reactor, a stainless steel wire mesh with a dispersing function is arranged at the upper part, an upper baffle plate is arranged at the lower part of the stainless steel wire mesh, a plurality of tube arrays are welded below the upper baffle plate, and the tail ends of the tube arrays are welded with a lower baffle plate; the tubes are distributed and arranged in a regular triangle; the tube array is internally filled with a plurality of cylindrical packed catalysts; the outer diameter of the packed catalyst is equal to the inner diameter of the tube array of the methanol oxidation reactor; the inner diameter of each tube row is more than or equal to 25mm, the length of each tube row is more than or equal to 1500mm, the number N of packed catalysts in each tube row is more than or equal to 5, and the height of the packed catalysts is more than or equal to 100mm; the packed catalyst comprises a stainless steel plane wire mesh, a stainless steel corrugated wire mesh and a catalyst A: the catalyst A is uniformly distributed on the stainless steel plane wire mesh, the stainless steel corrugated wire mesh and the stainless steel plane wire mesh are tiled and overlapped to cover the catalyst A, the edge is closed, and one end is taken as an axle center to be rolled into a solid cylindrical packed catalyst;
The extraction separation tower (4) is internally provided with tower internals, wherein the tower internals are any one of structured packing and tower plates; if the packing is structured packing, the number of the packing sections is N, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3 meters; if the plate is a column plate, the number of theoretical plates is M, and M is less than or equal to 1 and less than or equal to 100;
the number of layers N of the fixed bed in the multistage fixed bed reactor (12) is as follows: 1-10, wherein N is less than or equal to the 1;
the fractionating tower (13) is internally provided with tower internals, wherein the tower internals are any one of structured packing and tower plates; if the packing is structured packing, the number of the packing sections is N, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3 meters; if the plates are the trays, the theoretical plate number is M, and M is less than or equal to 1 and less than or equal to 100.
6. The apparatus of claim 4, wherein the extractant added thereto from the extractant feed port 2D is pure benzene.
7. The apparatus according to claim 4, wherein the extraction catalytic reaction column (2), the internals comprise: demister (20), distributor (28), packing assembly (23): the uppermost end in the extraction catalytic reaction tower is provided with a foam remover (20) and a distributor (28) below the foam remover; the distributor (28) is filled with a plurality of sections of filler assemblies (23) downwards, and a redistributor (26) is arranged between each section of filler assemblies (23); -said filler assembly (23) communicating with adjacent said distributor (28), said redistributor (26);
The packing assembly (23) is a multifunctional membrane assembly and comprises a plurality of vertically arranged up-and-down through tubes (251) which are arranged into a tube bed and fixed by a tube plate (27), a plurality of small holes (252) are formed in the whole body of each tube (251), sintered up-and-down through functional tubes (253) are inserted into the tubes (251), functional membranes (255) are formed by composite firing of the inner surfaces of the functional tubes (253), and the functional tubes (253) are internally filled with packing (254);
sealing materials are arranged at the upper end and the lower end of a gap between the tube array (251) and the functional tube (253) for sealing and fixing; the packing assembly (23) is communicated with the adjacent distributor (28) and the redistributors (26) through the functional pipes (253) to form a reaction channel; a dehydration runner is formed among the filler component (23), the redistributor (26) and the side wall of the reaction tower (2);
the top of the reaction tower (2) is provided with the exhaust port 2C (212), the bottom of the reaction tower is provided with the discharge port 2B (214), the side wall of the bottom of the reaction tower (2) is provided with the feed port 2A (213), the lowest filler component (23) is provided with the water removal port 2E (215) on the side wall of the reaction tower (2), and the uppermost distributor of the reaction tower (2) is communicated with the extractant feed port 2D (211) arranged on the side wall of the reaction tower (2);
The tube plates (27) at the bottommost layer are closed water receiving plates, all the tube plates (27) above the bottom layer are communicated through downcomers (50), a vacuumizing port is formed in the tube plate (27) at the topmost layer and is connected with an external vacuumizing system, and all the spaces outside the tubes (251) at each section and communicated by the downcomers (50) are vacuumized;
the foam remover (20), the distributor (28) and the redistributor (26) are internally formed by stainless steel corrugated wire meshes; the distributor (28) and the redistributor (26) are respectively provided with a plurality of diversion ports communicated with the functional pipe (253).
8. The device according to claim 7, wherein the functional tube (253) is made by composite firing of ZSM-5 with the inner surface of the functional tube (253); the filler (254) is a cylindrical stainless steel corrugated wire mesh structured filler; the sealing material is a polytetrafluoroethylene sealing gasket or a metal winding gasket, and an anti-corrosion rubber gasket.
9. The device according to claim 7, wherein the packing assembly (23) is filled in segments, the filling amount is N sections, N is less than or equal to 1 and less than or equal to 100, and the height of each section is 1-3m; each section of filling functional pipe 253 is M, and M is more than or equal to 1 and less than or equal to 5000; each pipe diameter is D, and D is more than or equal to 5 and less than or equal to 200cm; the diameter of the small hole (252) is 1-50mm.
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| CN102432441A (en) * | 2011-09-30 | 2012-05-02 | 天津大学 | Synthesis method of polymethoxy methylal |
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| CN106957221A (en) * | 2017-05-05 | 2017-07-18 | 凯瑞环保科技股份有限公司 | The device and method of polymethoxy dimethyl ether is produced in a kind of methanol oxidation |
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