CN114949907A - Device and method for separating dimethyl carbonate and methanol azeotrope with low energy consumption - Google Patents
Device and method for separating dimethyl carbonate and methanol azeotrope with low energy consumption Download PDFInfo
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- CN114949907A CN114949907A CN202210715908.5A CN202210715908A CN114949907A CN 114949907 A CN114949907 A CN 114949907A CN 202210715908 A CN202210715908 A CN 202210715908A CN 114949907 A CN114949907 A CN 114949907A
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- pervaporation membrane
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- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 title claims abstract description 150
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 title claims abstract description 75
- 238000000034 method Methods 0.000 title claims abstract description 37
- 238000005265 energy consumption Methods 0.000 title abstract description 13
- 239000012528 membrane Substances 0.000 claims abstract description 112
- 238000005373 pervaporation Methods 0.000 claims abstract description 76
- 239000007788 liquid Substances 0.000 claims abstract description 7
- 239000012530 fluid Substances 0.000 claims description 31
- 230000000149 penetrating effect Effects 0.000 claims description 31
- 238000010992 reflux Methods 0.000 claims description 17
- 239000002994 raw material Substances 0.000 claims description 14
- 238000004821 distillation Methods 0.000 claims description 11
- 239000012071 phase Substances 0.000 claims description 8
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 7
- 239000002131 composite material Substances 0.000 claims description 6
- HQYALQRYBUJWDH-UHFFFAOYSA-N trimethoxy(propyl)silane Chemical compound CCC[Si](OC)(OC)OC HQYALQRYBUJWDH-UHFFFAOYSA-N 0.000 claims description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 4
- 239000012466 permeate Substances 0.000 claims description 4
- 239000012465 retentate Substances 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- 239000010703 silicon Substances 0.000 claims description 4
- 239000007791 liquid phase Substances 0.000 claims description 3
- PYOKTQVLKOAHRM-UHFFFAOYSA-N triethoxy(3-triethoxysilylpropyl)silane Chemical compound CCO[Si](OCC)(OCC)CCC[Si](OCC)(OCC)OCC PYOKTQVLKOAHRM-UHFFFAOYSA-N 0.000 claims description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 2
- 229910052593 corundum Inorganic materials 0.000 claims description 2
- 239000010431 corundum Substances 0.000 claims description 2
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 claims description 2
- 229910052863 mullite Inorganic materials 0.000 claims description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 claims description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 2
- 238000000926 separation method Methods 0.000 abstract description 18
- 238000004519 manufacturing process Methods 0.000 abstract description 4
- 230000007613 environmental effect Effects 0.000 abstract 1
- 230000002265 prevention Effects 0.000 abstract 1
- 238000000746 purification Methods 0.000 abstract 1
- 239000000047 product Substances 0.000 description 22
- 239000000203 mixture Substances 0.000 description 10
- 239000007789 gas Substances 0.000 description 6
- 238000005810 carbonylation reaction Methods 0.000 description 5
- 239000003054 catalyst Substances 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- 238000003786 synthesis reaction Methods 0.000 description 5
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 description 4
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000006227 byproduct Substances 0.000 description 4
- 230000006315 carbonylation Effects 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 230000000087 stabilizing effect Effects 0.000 description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 3
- 238000006136 alcoholysis reaction Methods 0.000 description 3
- 239000004202 carbamide Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005832 oxidative carbonylation reaction Methods 0.000 description 3
- 230000035515 penetration Effects 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 2
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical compound [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 2
- 229940045803 cuprous chloride Drugs 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 150000002148 esters Chemical group 0.000 description 2
- 238000000895 extractive distillation Methods 0.000 description 2
- 239000003254 gasoline additive Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- BLLFVUPNHCTMSV-UHFFFAOYSA-N methyl nitrite Chemical compound CON=O BLLFVUPNHCTMSV-UHFFFAOYSA-N 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 229920000515 polycarbonate Polymers 0.000 description 2
- 239000004417 polycarbonate Substances 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- PKDCQJMRWCHQOH-UHFFFAOYSA-N triethoxysilicon Chemical compound CCO[Si](OCC)OCC PKDCQJMRWCHQOH-UHFFFAOYSA-N 0.000 description 2
- 238000009834 vaporization Methods 0.000 description 2
- 230000008016 vaporization Effects 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- LOMVENUNSWAXEN-UHFFFAOYSA-N Methyl oxalate Chemical compound COC(=O)C(=O)OC LOMVENUNSWAXEN-UHFFFAOYSA-N 0.000 description 1
- 206010029350 Neurotoxicity Diseases 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 206010044221 Toxic encephalopathy Diseases 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 239000013064 chemical raw material Substances 0.000 description 1
- 231100000481 chemical toxicant Toxicity 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- GUNDKLAGHABJDI-UHFFFAOYSA-N dimethyl carbonate;methanol Chemical compound OC.COC(=O)OC GUNDKLAGHABJDI-UHFFFAOYSA-N 0.000 description 1
- VAYGXNSJCAHWJZ-UHFFFAOYSA-N dimethyl sulfate Chemical compound COS(=O)(=O)OC VAYGXNSJCAHWJZ-UHFFFAOYSA-N 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000010842 industrial wastewater Substances 0.000 description 1
- 150000002576 ketones Chemical class 0.000 description 1
- CXHHBNMLPJOKQD-UHFFFAOYSA-M methyl carbonate Chemical compound COC([O-])=O CXHHBNMLPJOKQD-UHFFFAOYSA-M 0.000 description 1
- XMJHPCRAQCTCFT-UHFFFAOYSA-N methyl chloroformate Chemical compound COC(Cl)=O XMJHPCRAQCTCFT-UHFFFAOYSA-N 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000007069 methylation reaction Methods 0.000 description 1
- 230000007135 neurotoxicity Effects 0.000 description 1
- 231100000228 neurotoxicity Toxicity 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 235000013842 nitrous oxide Nutrition 0.000 description 1
- 231100000252 nontoxic Toxicity 0.000 description 1
- 230000003000 nontoxic effect Effects 0.000 description 1
- TVMXDCGIABBOFY-UHFFFAOYSA-N octane Chemical compound CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 1
- 238000011020 pilot scale process Methods 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 238000011112 process operation Methods 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 238000005809 transesterification reaction Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
- B01D3/145—One step being separation by permeation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
- C07C29/76—Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C29/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring
- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
- C07C29/76—Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment
- C07C29/80—Separation; Purification; Use of additives, e.g. for stabilisation by physical treatment by distillation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C68/00—Preparation of esters of carbonic or haloformic acids
- C07C68/08—Purification; Separation; Stabilisation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a device and a method for separating dimethyl carbonate and methanol, wherein in the device, an outlet on the permeation side of a first pervaporation membrane component is connected with an inlet of a second pervaporation membrane component, an outlet on the permeation side of the first pervaporation membrane component is connected with an inlet of a high-pressure rectifying tower, a residual liquid outlet of the second pervaporation membrane component is connected with an inlet of an atmospheric rectifying tower, and a fraction outlet on the top of the high-pressure rectifying tower is connected with an inlet of the atmospheric rectifying tower. The invention has the advantages that the two rectifying towers and the membrane system are combined to realize the purification of the dimethyl carbonate and the methanol by a two-stage separation method, the energy consumption is low, the safety, the environmental protection and the pollution prevention are realized, and the clean production can be realized.
Description
Technical Field
The invention belongs to the field of chemical separation, and particularly relates to a device and a method for separating dimethyl carbonate and methanol azeotrope with low energy consumption.
Background
Dimethyl carbonate (DMC) is a green solvent with excellent performance, and can be completely mixed with most of ketone, alcohol, ether and other solvents. DMC is nontoxic and contains functional groups such as methyl, carbonyl and the like in the structure, can replace highly toxic dimethyl sulfate, methyl chloroformate and phosgene to carry out methylation reaction to synthesize a plurality of downstream products with high added values, eliminates the pollution of the highly toxic chemicals to the environment, is an environment-friendly organic chemical intermediate, and becomes 'new cornerstone' in organic synthesis in a new period. With the rapid development of new energy fields at home and abroad, the electrolyte is used as a main solvent for the composition of the electrolyte, and the market demand is gradually expanding. Meanwhile, DMC can prepare high and new material polycarbonate through ester exchange, polymerization and other processes, becomes an important chemical raw material in the new field of polycarbonate production, and can greatly promote the growth of the industrial scale. The gasoline additive has a high oxygen content in the molecular structure, has a good octane number improving effect, and is considered to be one of the most potential gasoline additives.
The main production routes of DMC include phosgene process, methanol oxidation and carbonylation process, CO 2 Direct synthesis, urea alcoholysis and ester exchange synthesis. The phosgene method uses strong corrosive and virulent radioactive phosgene, the production process seriously pollutes the environment and has serious potential safety hazard, and the method is gradually eliminated. At present, CO 2 Direct joiningBoth the success and the urea alcoholysis process remain limited to the laboratory or to the pilot-scale research phase of kilotons/year. Oxidative carbonylation processes include direct oxidative carbonylation of methanol and indirect oxidative carbonylation. The indirect oxidation carbonylation method is that methanol and NOx firstly generate methyl nitrite, and the methyl nitrite generates carbonylation reaction to obtain DMC and N 2 O，N 2 The O is reoxidized to NOx. The advantage of this process is the low cost of the starting material, but the disadvantages are equally evident, N 2 O is known as laughing gas, has neurotoxicity and has a greenhouse effect of CO 2 300 times of the amount of the product, and simultaneously produces water as a byproduct and industrial wastewater, so the method is not environment-friendly. The DMC prepared by the method has lower purity, a large amount of byproducts (such as dimethyl oxalate and the like) of oxygen-containing compounds are generated, the byproducts of oxidation reaction are mostly common diseases, and the process difficulty of separating the byproducts into electronic-grade chemicals is higher. And the route adopts the noble metal catalyst, the catalyst price is higher, and along with the popularization of the technology, the price of the noble metal catalyst can be greatly increased. Meanwhile, a small amount of nitric acid with strong corrosiveness is generated in the continuous operation process of the technology. The liquid phase oxidation carbonylation method mainly uses cuprous chloride as a catalyst. The cuprous chloride in the reaction system has high corrosivity and high requirement on equipment, so the investment cost is high, the catalyst is easy to inactivate, and the service life is short.
Whether methanol oxidation carbonylation method or CO method is adopted 2 The direct synthesis, urea alcoholysis and transesterification synthesis all suffer from the problem of separation of methanol and DMC azeotropes. The azeotropic temperature of methanol and DMC is 63.7 ℃ under normal pressure, the azeotropic composition is 70wt% of methanol and 30wt% of DMC, and the common rectification process is difficult to realize the product refining requirement. For the separation of methanol and DMC, the main technological techniques studied at present are extractive distillation, pressure swing separation, recrystallization and membrane separation, and the extractive distillation and pressure swing separation are the most widely used in industrialization. The entrainer with high boiling point outside the system is often introduced in the extraction and rectification, the complete separation and recovery in the later period are difficult, the product quality is influenced, and the process operation is complicated. Pressure swing separation is realized by changing the volatility of azeotrope components by utilizing pressure change in the process, but the high-pressure rectification process has relatively high operation temperature and large energy consumption and heat loss, and the separation process needs to be urgently neededAnd carrying out reinforced upgrading.
The patent CN 104370698A and CN 104370699A disclose that dimethyl carbonate and methanol are separated, only one pressurizing tower or normal pressure tower is used on the membrane permeation side, the fraction at the top of the tower also comprises dimethyl carbonate, the fraction at the top of the tower directly returns to a reaction rectifying tower, the yield of the dimethyl carbonate is lower, the steam energy consumption is high, and no methanol product is obtained. Patent CN 110404422 a discloses an organic composite membrane for separating methanol and dimethyl carbonate, which has a much shorter service life than inorganic composite membranes in industrial applications. The patent CN 101143803A only considers the separation of dimethyl carbonate and methanol by using a membrane, does not consider the separation of components at the top of an atmospheric distillation tower and components at the retentate side of the membrane, and does not circulate among streams, thereby resulting in low yield of dimethyl carbonate, high energy consumption and being not beneficial to industrial popularization. The patents CN 201823480U and CN107206286A disclose that the front of dimethyl carbonate and methanol is an atmospheric tower, the bottom of the tower is a methanol product, the scientific principle is violated, the azeotropic mixture of the atmospheric tower and the methanol can not be separated theoretically, the tower kettle can not obtain any pure product, and if a rectifying tower is arranged at the front end of the membrane, the front end of the membrane must be a high-pressure tower. The azeotrope contains 70wt% of methanol, the heat of vaporization of methanol is very large, and if a membrane which is permeable to methanol preferentially is selected, the energy consumption is relatively high.
Disclosure of Invention
The invention aims to provide a device and a method for separating dimethyl carbonate and methanol azeotrope with low energy consumption, which are suitable for industrial popularization, wherein a method of preferentially permeating a dimethyl carbonate membrane separation technology and combining a rectifying tower is adopted for separation, two products of high-purity dimethyl carbonate and methanol can be simultaneously obtained, the separation effect and the product yield are improved, and the energy consumption is reduced.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a device for separating dimethyl carbonate and methanol is characterized in that an outlet at the permeation side of a first pervaporation membrane module is connected with an inlet of a second pervaporation membrane module, an outlet at the permeation side of the first pervaporation membrane module is connected with an inlet of a high-pressure rectifying tower, an outlet at the permeation side of the second pervaporation membrane module is connected with an inlet of an atmospheric rectifying tower, and an outlet at the top of the high-pressure rectifying tower is connected with an inlet of the atmospheric rectifying tower.
Further, the first pervaporation membrane module and the second pervaporation membrane module adopt a permselective dimethyl carbonate pervaporation membrane.
Further, the preferential penetration dimethyl carbonate pervaporation membrane is a tubular organic-inorganic composite membrane, the carrier of the preferential penetration dimethyl carbonate pervaporation membrane is alumina, corundum or mullite, and the upper layer of the preferential penetration dimethyl carbonate pervaporation membrane is alumina, titanium oxide or zirconium oxide; the organic film layer is an organic silicon hybrid film with controllable aperture formed by co-condensation of propyl trimethoxy silane and 1, 3-bis (triethoxysilyl) propane.
Further, the permeate side outlet of the second pervaporation membrane module is connected with the inlet of the first pervaporation membrane module.
Further, a heater is arranged at the inlet of the first pervaporation membrane module.
Further, an overhead fraction outlet of the atmospheric distillation tower is connected with an inlet of the first pervaporation membrane module.
Further, the tower top heat of the high-pressure rectifying tower supplies heat to a reboiler of the normal-pressure rectifying tower.
Further, an outlet at the permeation side of the first pervaporation membrane module is connected with a first condenser, and an outlet at the permeation side of the second pervaporation membrane module is connected with a second condenser.
Further, the first pervaporation membrane module and the second pervaporation membrane module are provided with a driving force by a vacuum system.
The invention also provides a method for separating dimethyl carbonate and methanol, which comprises the following steps:
raw materials enter a first pervaporation membrane module, a first penetrating fluid obtained after pervaporation treatment enters a high-pressure rectifying tower for rectification treatment, and a first residual liquid enters a second pervaporation membrane module; the second residual liquid obtained by the second pervaporation membrane module enters a normal pressure rectifying tower for rectification; obtaining dimethyl carbonate at the bottom of the high-pressure rectifying tower; and obtaining methanol at the bottom of the atmospheric distillation tower.
Preferably, the operating temperature of the first pervaporation membrane module is 40-60 ℃.
Preferably, the operating temperature of the second pervaporation membrane module is 40-60 ℃.
Preferably, the concentration of dimethyl carbonate in the raw material is 20-30 wt%, and the raw material enters the first pervaporation membrane module in a gas phase or liquid phase mode.
The concentration of dimethyl carbonate in the first penetrating fluid is 40-90 wt%. The concentration of dimethyl carbonate in the penetrating fluid obtained by the second membrane module is 20-40 wt%. The concentration of the dimethyl carbonate in the second residual solution is 0.5-20 wt%.
Preferably, the absolute pressure of the vacuum system is 1000-10000 Pa.
Preferably, the reflux ratio of the high-pressure rectifying tower is 0.5-5, the operating pressure is 0.2-0.7 MPa, and the tower top temperature is 90-130 ℃.
Preferably, the reflux ratio of the atmospheric distillation tower is 0.5-5, the operating pressure is 0.01-0.1 MPa, and the tower top temperature is 60-70 ℃.
The invention has the following beneficial effects:
1. the invention adopts the organic-inorganic composite membrane which is permeable to dimethyl carbonate preferentially, the composite membrane can effectively break the azeotropic bottleneck of methanol-dimethyl carbonate, change the relative volatility of an azeotrope, greatly reduce the steam energy consumption, and the higher the selectivity of the membrane to the dimethyl carbonate is, the lower the steam energy consumption is, and the selectivity and the stability of the membrane selected by the invention are superior to those of the membranes reported by literature data.
2. The device adopted by the invention is provided with a two-stage membrane separation system, the first-stage penetrating fluid enters a high-pressure tower, and the second-stage penetrating fluid and the raw materials are mixed and then enter a first-stage membrane system. The heat of the top of the high-pressure tower is used for heating a tower kettle of the atmospheric tower, the high-low pressure rectifying tower is matched with the membrane separation system, the steam consumption of each ton of dimethyl carbonate in the traditional pressure swing rectifying process is about 7.2 tons under the condition of heat recycling, the steam energy consumption of the invention is only 30-50 percent of that of the traditional pressure swing rectifying process, the treatment capacity of the high-pressure tower is only 40 percent of that of the high-pressure tower in the traditional pressure swing rectifying process, and the treatment capacity of the atmospheric tower is only 60 percent of that of the atmospheric tower in the traditional pressure swing rectifying process.
3. The device and the process can reduce the operation pressure and the treatment capacity of the high-pressure tower, improve the yield of the dimethyl carbonate and further reduce the separation difficulty and the tower load.
4. The invention adopts continuous operation, can simultaneously obtain two products of dimethyl carbonate and methanol with the purity of more than or equal to 99.5wt percent, circularly separate all materials in the system, has high yield and does not generate three wastes.
5. The process of the rectifying tower and the membrane, which is provided by the invention, comprehensively considers the investment and the operating cost, and is suitable for industrial popularization.
Drawings
FIG. 1 is a schematic diagram of an apparatus for separating dimethyl carbonate and methanol.
Wherein, 1 is a first pervaporation membrane component, 2 is a second pervaporation membrane component, 3 is a high-pressure rectifying tower, 4 is an atmospheric rectifying tower, 5 is a first condenser, 6 is a second condenser, 7 is a reboiler of the high-pressure rectifying tower, 8 is the reboiler of the atmospheric rectifying tower, 9 is a heater, and 10 is a vacuum system. In the figure the solid arrows represent the material flow direction and the dashed arrows represent the heat supply direction.
Detailed Description
The present invention will be further explained with reference to examples. The following examples are provided only for illustrating the present invention and are not intended to limit the scope of the present invention.
As shown in fig. 1, in the apparatus for separating dimethyl carbonate and methanol, an outlet on a retentate side of a first pervaporation membrane module 1 is connected to an inlet of a second pervaporation membrane module 2, an outlet on a permeate side of the first pervaporation membrane module 2 is connected to an inlet of a high-pressure rectification column 3, an outlet on a retentate side of the second pervaporation membrane module 2 is connected to an inlet of an atmospheric rectification column 4, and an outlet of a fraction on a top of the high-pressure rectification column 3 is connected to an inlet of the atmospheric rectification column 4.
The first pervaporation membrane module 1 and the second pervaporation membrane module 2 adopt a permselective dimethyl carbonate pervaporation membrane.
And the outlet at the permeation side of the second pervaporation membrane module 2 is connected with the inlet of the first pervaporation membrane module 1.
A heater 9 is arranged at the inlet of the first pervaporation membrane module 1.
And the top fraction outlet of the atmospheric distillation tower 4 is connected with the inlet of the first pervaporation membrane module 1.
The heat of the high-pressure rectifying tower 3 supplies heat to a reboiler 8 of the normal-pressure rectifying tower 4.
The outlet of the permeation side of the first pervaporation membrane module 1 is connected with a first condenser 5, and the outlet of the permeation side of the second pervaporation membrane module 2 is connected with a second condenser 6.
The first pervaporation membrane module 1 and the second pervaporation membrane module 2 are driven by a vacuum system 10.
Example 1
The raw material containing 30wt% of dimethyl carbonate and methanol is heated to 50 ℃ by adopting the device and then enters the membrane module, and the raw material is separated by the two-stage membrane module through the methyl carbonate pervaporation membrane preferentially permeating the organic silicon hybrid membrane/alumina ceramic which is co-condensed by propyl trimethoxy silane and 1, 3-bis (triethoxysilyl) propane. The downstream side of the membrane adopts a vacuum pumping and condensing mode to form the vapor partial pressure difference of components on the upstream side and the downstream side of the membrane. Penetrating fluid steam enters a first condenser and a second condenser respectively under the suction of 5000Pa of absolute pressure of a vacuum unit to obtain a first penetrating fluid and a second penetrating fluid, wherein the concentration of dimethyl carbonate in the first penetrating fluid is 50wt%, and the first penetrating fluid enters a high-pressure rectifying tower for treatment. The concentration of the dimethyl carbonate in the second penetrating fluid is 28wt percent, and the raw material containing 30wt percent of dimethyl carbonate and methanol is mixed and then returned to the first pervaporation membrane module for circular treatment.
The first penetrating fluid is conveyed to the middle part of a high-pressure rectifying tower by a tower feeding pump, the high-pressure rectifying tower is operated under the pressure of 0.2MPa, the reflux ratio is 1, the temperature at the top of the tower is 130 ℃, a reboiler at the bottom of the tower is heated and vaporized, after the full-reflux stabilizing operation, part of the first penetrating fluid is condensed and refluxed to the top of the high-pressure rectifying tower, a methanol mixture containing 20 percent of dimethyl carbonate is extracted from the top of the tower, and 99.8 percent of DMC product by weight is extracted from the bottom of the tower. And the product at the top of the tower enters an atmospheric tower for treatment. The heat of the tower top product is provided for a tower kettle reboiler of the atmospheric distillation tower.
And (3) conveying the second residual solution and a product at the top of the high-pressure rectifying tower to the middle part of the normal-pressure rectifying tower by a tower feeding pump, wherein the normal-pressure rectifying tower is operated under the pressure of 0.05MPa, the reflux ratio is 1, the temperature at the top of the tower is 65 ℃, a reboiler at the bottom of the tower is heated and vaporized, after the full-reflux stable operation, a part of the second residual solution is refluxed to the top of the normal-pressure rectifying tower after being condensed by a condenser at the top of the tower, a methanol mixture containing 25wt% of DMC is partially extracted, and a 99.5wt% methanol product is extracted at the bottom of the tower. And the product at the top of the tower circularly enters a first pervaporation membrane module to be treated. The heat of the tower bottom comes from the heat of the tower top of the high-pressure rectifying tower.
Example 2
The device is adopted to make the gas phase raw material of 28wt% dimethyl carbonate and methanol with the temperature of 60 ℃ enter a membrane component, and an organic silicon hybrid membrane/alumina ceramic co-condensed by propyl trimethoxy silane and 1, 3-bis (triethoxy silicon-based) propane is adopted to preferentially permeate the dimethyl carbonate pervaporation membrane, and is separated by a two-stage membrane component. The downstream side of the membrane adopts a vacuum pumping and condensing mode to form the vapor partial pressure difference of components on the upstream side and the downstream side of the membrane. Penetrating fluid steam enters a first condenser and a second condenser respectively under the suction of 10000Pa absolute pressure of a vacuum unit to obtain a first penetrating fluid and a second penetrating fluid, wherein the concentration of dimethyl carbonate in the first penetrating fluid is 60wt%, and the first penetrating fluid enters a high-pressure rectifying tower for treatment. The concentration of the dimethyl carbonate in the second penetrating fluid is 32wt percent, after heating and vaporization, the second penetrating fluid is mixed with the raw material containing 28wt percent of dimethyl carbonate and methanol and then returns to the first pervaporation membrane module for circulation treatment.
The first penetrating fluid is conveyed to the middle part of a high-pressure rectifying tower by a tower feeding pump, the high-pressure rectifying tower is operated under the pressure of 0.4MPa, the reflux ratio is 5, the temperature at the top of the tower is 90 ℃, a reboiler at the bottom of the tower is heated and vaporized, after the full-reflux stabilizing operation, part of the first penetrating fluid is condensed and refluxed to the top of the high-pressure rectifying tower, a methanol mixture containing 20 percent of dimethyl carbonate is extracted from a gas phase part and enters a normal pressure tower for treatment, and 99.7 percent of DMC products by weight are extracted from the bottom of the tower.
And (3) conveying the second residual solution and a tower top product of the high-pressure rectifying tower to the middle part of the normal-pressure rectifying tower by a tower feed pump, wherein the normal-pressure rectifying tower is operated under the pressure of 0.01MPa, the reflux ratio is 5, the temperature at the top of the tower is 70 ℃, a reboiler at the tower bottom is heated and vaporized, after the full-reflux stabilizing operation, part of the second residual solution reflows to the top of the normal-pressure rectifying tower, a methanol mixture containing 26wt% of DMC is extracted from a gas phase, the methanol mixture enters a first pervaporation membrane component for treatment, and a methanol product with the concentration of 99.5wt% is extracted from the tower bottom.
Example 3
The raw materials of 20wt% dimethyl carbonate and methanol are heated to 40 ℃ by adopting the device, enter a membrane component, and are separated by a two-stage membrane component by adopting an organosilicon hybrid membrane/alumina ceramic which is co-condensed by propyl trimethoxy silane and 1, 3-bis (triethoxy silicon-based) propane and preferentially permeating the dimethyl carbonate pervaporation membrane. The downstream side of the membrane adopts a vacuum pumping and condensing mode to form the vapor partial pressure difference of components on the upstream side and the downstream side of the membrane. Penetrating fluid steam enters a first condenser and a second condenser respectively under the suction of 1000Pa of absolute pressure of a vacuum unit to obtain a first penetrating fluid and a second penetrating fluid, wherein the concentration of dimethyl carbonate in the first penetrating fluid is 40wt%, and the first penetrating fluid enters a high-pressure rectifying tower for treatment. The concentration of the dimethyl carbonate in the second penetrating fluid is 32wt percent, and the second penetrating fluid is heated and gasified, mixed with the raw material containing 20wt percent of dimethyl carbonate and methanol and returned to the first pervaporation membrane module for circular treatment.
The first penetrating fluid is conveyed to the middle part of a high-pressure rectifying tower by a tower feeding pump, the high-pressure rectifying tower is operated under the pressure of 0.7MPa, the reflux ratio is 0.5, the temperature at the top of the tower is 128 ℃, a reboiler at the bottom of the tower is heated and vaporized, after the full reflux stabilization operation, partial condensing reflux is carried out to the top of the high-pressure rectifying tower, a methanol mixture containing 20 percent of dimethyl carbonate is extracted from a gas phase part and enters a normal pressure tower for treatment, and 99.7 percent of DMC products are extracted from the bottom of the tower.
The second residual liquid and the tower top product of the high-pressure rectifying tower are conveyed to the middle part of the normal-pressure rectifying tower by a tower feeding pump, the normal-pressure rectifying tower is operated under the pressure of 0.1MPa, the reflux ratio is 0.5, the temperature at the top of the tower is 60 ℃, a reboiler at the bottom of the tower is heated and vaporized, after the full reflux stabilizing operation, part of the second residual liquid reflows to the top of the normal-pressure rectifying tower, a methanol mixture containing 26wt% of DMC is extracted from a gas phase and enters a first pervaporation membrane component for treatment, and a methanol product with 99.5wt% is extracted from the bottom of the tower.
Claims (10)
1. The device for separating the dimethyl carbonate and the methanol is characterized in that an outlet on the permeation side of a first pervaporation membrane module is connected with an inlet of a second pervaporation membrane module, an outlet on the permeation side of the first pervaporation membrane module is connected with an inlet of a high-pressure rectifying tower, a retentate outlet of the second pervaporation membrane module is connected with an inlet of an atmospheric rectifying tower, and an outlet of fraction at the top of the high-pressure rectifying tower is connected with an inlet of the atmospheric rectifying tower.
2. The apparatus of claim 1, wherein the first pervaporation membrane module and the second pervaporation membrane module are dimethyl carbonate permselective pervaporation membranes; preferably, the permselective dimethyl carbonate pervaporation membrane is a tubular organic-inorganic composite membrane, the carrier of the permselective dimethyl carbonate pervaporation membrane is alumina, corundum or mullite, and the upper layer of the permselective dimethyl carbonate pervaporation membrane is alumina, titanium oxide or zirconium oxide; the organic film layer is an organic silicon hybrid film with controllable aperture, which is formed by co-condensing propyl trimethoxy silane and 1, 3-bis (triethoxysilyl) propane.
3. The apparatus of claim 1, wherein a permeate side outlet of the second pervaporation membrane module is connected to an inlet of the first pervaporation membrane module.
4. The apparatus of claim 1, wherein a heater is disposed at an inlet of the first pervaporation membrane module.
5. The apparatus of claim 1, wherein an overhead outlet of the atmospheric distillation column is connected to an inlet of the first pervaporation membrane module.
6. The apparatus of claim 1, wherein the overhead heat of the high pressure distillation column supplies heat to a reboiler of the atmospheric distillation column.
7. A method for separating dimethyl carbonate and methanol, comprising:
raw materials enter a first pervaporation membrane module, a first penetrating fluid obtained after pervaporation treatment enters a high-pressure rectifying tower for rectification treatment, and a first residual liquid enters a second pervaporation membrane module; the second residual liquid obtained by the second pervaporation membrane module enters a normal pressure rectifying tower for rectification; obtaining dimethyl carbonate at the bottom of the high-pressure rectifying tower; and obtaining methanol at the bottom of the atmospheric distillation tower.
8. The method according to claim 7, wherein the operating temperature of the first pervaporation membrane module is 40 to 60 ℃; the operating temperature of the second pervaporation membrane module is 40-60 ℃.
9. The method according to claim 7, wherein the concentration of dimethyl carbonate in the raw material is 20-30 wt%, and the raw material enters the first pervaporation membrane module in a gas phase or a liquid phase.
10. The method according to claim 7, wherein the reflux ratio of the high-pressure rectifying tower is 0.5-5, the operating pressure is 0.2-0.7 MPa, and the tower top temperature is 90-130 ℃; the reflux ratio of the atmospheric distillation tower is 0.5-5, the operating pressure is 0.01-0.1 MPa, and the tower top temperature is 60-70 ℃.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115572215A (en) * | 2022-10-24 | 2023-01-06 | 浙江汇甬新材料有限公司 | Separation method of methanol and dimethyl carbonate azeotrope by membrane separation coupled rectification |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4408697A1 (en) * | 1994-03-15 | 1995-09-21 | Huels Chemische Werke Ag | Sepn. of di:methyl carbonate and methanol from mixt. by pervaporation |
| CN101143803A (en) * | 2007-09-18 | 2008-03-19 | 中国石油天然气股份有限公司 | Method for separating dimethyl carbonate and methanol azeotrope |
| US20170349530A1 (en) * | 2014-12-24 | 2017-12-07 | Posco | Method and apparatus for purification of dimethyl carbonate using pervaporation |
| CN114621056A (en) * | 2022-04-19 | 2022-06-14 | 烟台国邦化工机械科技有限公司 | Process for separating dimethyl carbonate and methanol azeotrope |
| CN218636644U (en) * | 2022-06-23 | 2023-03-17 | 江苏久膜高科技股份有限公司 | Device for separating dimethyl carbonate and methanol azeotrope with low energy consumption |
-
2022
- 2022-06-23 CN CN202210715908.5A patent/CN114949907A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4408697A1 (en) * | 1994-03-15 | 1995-09-21 | Huels Chemische Werke Ag | Sepn. of di:methyl carbonate and methanol from mixt. by pervaporation |
| CN101143803A (en) * | 2007-09-18 | 2008-03-19 | 中国石油天然气股份有限公司 | Method for separating dimethyl carbonate and methanol azeotrope |
| US20170349530A1 (en) * | 2014-12-24 | 2017-12-07 | Posco | Method and apparatus for purification of dimethyl carbonate using pervaporation |
| CN114621056A (en) * | 2022-04-19 | 2022-06-14 | 烟台国邦化工机械科技有限公司 | Process for separating dimethyl carbonate and methanol azeotrope |
| CN218636644U (en) * | 2022-06-23 | 2023-03-17 | 江苏久膜高科技股份有限公司 | Device for separating dimethyl carbonate and methanol azeotrope with low energy consumption |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115572215A (en) * | 2022-10-24 | 2023-01-06 | 浙江汇甬新材料有限公司 | Separation method of methanol and dimethyl carbonate azeotrope by membrane separation coupled rectification |
| CN115572215B (en) * | 2022-10-24 | 2024-04-30 | 浙江汇甬新材料有限公司 | Separation method of methanol and dimethyl carbonate azeotrope through coupling and rectification of membrane separation |
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