CN112851477A - Method for preparing ethylene glycol by ethylene oxidation - Google Patents
Method for preparing ethylene glycol by ethylene oxidation Download PDFInfo
- Publication number
- CN112851477A CN112851477A CN201911176887.9A CN201911176887A CN112851477A CN 112851477 A CN112851477 A CN 112851477A CN 201911176887 A CN201911176887 A CN 201911176887A CN 112851477 A CN112851477 A CN 112851477A
- Authority
- CN
- China
- Prior art keywords
- solid
- membrane
- liquid
- separation
- molecular sieve
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- 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
- C07C29/48—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by oxidation reactions with formation of hydroxy groups
-
- 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
-
- 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
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Catalysts (AREA)
Abstract
The present disclosure relates to a method for preparing ethylene glycol by oxidizing ethylene, wherein the method comprises: under the condition of oxidation reaction, in the presence of a surfactant, ethylene, aqueous hydrogen peroxide, a catalyst containing a titanium silicalite molecular sieve and an organic solvent are subjected to contact reaction in a slurry bed reactor, the obtained mixed slurry is subjected to solid-liquid separation, and the obtained liquid phase is subjected to membrane separation treatment to obtain the ethylene glycol. The method has high ethylene conversion rate and selectivity and good product purity.
Description
Technical Field
The present disclosure relates to a process for the oxidation of ethylene to ethylene glycol.
Background
Ethylene glycol is an important basic organic raw material, has the characteristics of high boiling point, low freezing point, weak reducibility and the like, is mainly used for producing polyester fibers, moisture absorbents, plasticizers, surfactants, cosmetics and explosives, can also be used as solvents, antifreeze agents, dehydrating agents, wetting agents and the like of dyes, printing ink and the like, and has wide application.
Ethylene glycol is an important ring in chemical fiber industrial chains, wherein the consumption of polyester (including polyester fiber, polyester plastic, polyester film and the like) accounts for over 90 percent of the total consumption of ethylene glycol in China. With the rapid development of domestic polyester and chemical fiber product markets, China has become the main world producing countries of ethylene glycol. In 2018, the yield of ethylene glycol in China accounts for about 24% of the total world amount, but the consumption accounts for about 51%, and the dependence on imported products is still large.
The existing ethylene glycol synthesis method mainly comprises an ethylene oxide hydration method, an ethylene direct oxidation method and the like; among them, the ethylene oxide hydration method can be classified into a direct hydration method, a catalytic hydration method and a pressurized hydration method. The main defects of the direct hydration method and the pressurized hydration method are that a production device needs to be provided with a plurality of evaporators, the number of equipment is large, the energy consumption is high, and the production cost of the ethylene glycol is directly influenced. The catalytic hydration method reduces the water ratio in the direct hydration method process and can ensure higher EG selectivity, but the method uses molybdate, tungstate, vanadate and other catalysts with high cost and great harm to the environment.
From the foregoing, the existing ethylene oxide hydration method for preparing ethylene glycol uses ethylene oxide as a raw material, and has complex process and high cost. The direct ethylene oxidation method adopts ethylene as a raw material, and the ethylene is oxidized into ethylene glycol in one step under the action of a titanium silicalite molecular sieve/hydrogen peroxide system, but the method has the defect that the purity of the product ethylene glycol is not high enough.
Disclosure of Invention
The purpose of the present disclosure is to provide a method for preparing ethylene glycol with higher product purity.
In order to achieve the above object, the present disclosure provides a method for preparing ethylene glycol by oxidizing ethylene, the method comprising: under the condition of oxidation reaction, in the presence of a surfactant, enabling ethylene, aqueous hydrogen peroxide, a catalyst containing a titanium silicalite molecular sieve and an organic solvent to contact and react in a slurry bed reactor, and carrying out solid-liquid separation treatment on the obtained mixed slurry to obtain a mixed solution containing ethylene glycol; subjecting the mixed solution to membrane separation treatment.
Alternatively, the slurry bed reactor is operated continuously; the conditions of the oxidation reaction include: the molar ratio of the ethylene to the hydrogen peroxide is 1: 1-5, preferably 1: 1.1-4; the mass ratio of the organic solvent, the catalyst and the ethylene is 0.1-100: 0.001-1: 1, preferably 0.5-5: 0.01-0.4: 1; the contact temperature is 15-220 ℃, and preferably 25-80 ℃; the pressure is 0.1-8 MPa, preferably 0.5-1.8 MPa; the time is 0.1 to 20 hours, preferably 4 to 9 hours.
Optionally, the concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution is 20 to 80 wt%, preferably 30 to 70 wt%.
Optionally, the slurry bed reactor is a gas-liquid-solid three-phase slurry bed reactor.
Optionally, the solid-liquid separation treatment comprises: one or more of solid-liquid settling separation, solid-liquid cyclone separation, filtration and solid-liquid membrane separation.
Optionally, a solid-liquid separation assembly is arranged in the slurry bed reactor; and/or the outlet of the slurry bed reactor is communicated with a solid-liquid separator;
the method further comprises the following steps: carrying out solid-liquid separation on the mixed slurry through the solid-liquid separation component and/or the solid-liquid separator to obtain the mixed liquid and a solid-phase material containing catalyst particles; continuing the reaction with the solid phase feed in the slurry bed reactor.
Optionally, the solid-liquid separation assembly is a filtering assembly, and the filtering pore size of the filtering assembly is 30-150 μm; the solid-liquid separator is a solid-liquid membrane separator, and the membrane aperture of the solid-liquid membrane separator is less than 10 mu m;
the method comprises the following steps: carrying out first solid-liquid separation on the mixed slurry through the filtering component to obtain a first solid-phase material and a first solid-liquid mixture, and continuing the reaction of the first solid-phase material in the slurry bed reactor; and enabling the first solid-liquid mixture to enter the solid-liquid membrane separator for second solid-liquid separation to obtain a second solid-phase material and the mixed liquid.
Optionally, the membrane separation process comprises an evaporation permeable membrane separation, and the process conditions of the evaporation permeable membrane separation comprise: the vacuum degree at the downstream side of the separation membrane is 0.3-0.7 kPa, the temperature is 20-90 ℃, and the feeding flow rate is 50-120L/h.
Optionally, the separation membrane used in the evaporation-permeation membrane separation is a PVA membrane, a PVA/PES composite membrane, a PS composite membrane, a PAA/PVA IPN composite membrane, a PAAM/PVA IPN composite membrane, a CS/PS composite membrane,Surface cross-linked CS/PES composite membrane, PVP membrane, SPE membrane, SPEEK/PVDF composite membrane and microporous TiO2One or more of the membranes.
Optionally, the amount of the surfactant is 5 to 50000ppm by weight of the organic solvent; the surfactant is selected from one or more of Tween surfactant, Ninale surfactant, span surfactant, TX-10 surfactant, OP-10 surfactant and AEO-9 surfactant.
Optionally, the catalyst containing a titanium silicalite molecular sieve is a titanium silicalite molecular sieve; the titanium silicalite molecular sieve is at least one of a titanium silicalite molecular sieve with an MFI structure, a titanium silicalite molecular sieve with an MEL structure, a titanium silicalite molecular sieve with a BEA structure, a titanium silicalite molecular sieve with an MWW structure, a titanium silicalite molecular sieve with an MOR structure, a titanium silicalite molecular sieve with a TUN structure and a titanium silicalite molecular sieve with a two-dimensional hexagonal structure.
Optionally, the titanium silicalite molecular sieve is of an MFI structure, the crystal grains are of a hollow structure, the radial length of a cavity part of the hollow structure is 5-300 nanometers, and the titanium silicalite molecular sieve is P/P at 25 DEG C0The benzene adsorption amount measured under the conditions of 0.10 and the adsorption time of 1 hour is at least 70 mg/g, and a hysteresis loop exists between the adsorption isotherm and the desorption isotherm of the low-temperature nitrogen adsorption of the titanium silicalite molecular sieve.
Optionally, the organic solvent is one or more of a C3-C10 ketone, a C1-C10 alcohol, a C1-C10 carboxylic acid, and a C1-C10 organohaloalkane.
Optionally, the method further comprises: and rectifying the ethylene glycol crude product obtained by the membrane separation treatment to obtain the ethylene glycol.
According to the technical scheme, the titanium silicalite molecular sieve/hydrogen peroxide system is adopted to react in the slurry bed reactor, and the mixed slurry obtained by membrane separation treatment reaction is adopted.
Additional features and advantages of the disclosure will be set forth in the detailed description which follows.
Detailed Description
The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.
The present disclosure provides a method for preparing ethylene glycol by oxidizing ethylene, wherein the method comprises: under the condition of oxidation reaction, in the presence of a surfactant, enabling ethylene, aqueous hydrogen peroxide, a titanium silicalite molecular sieve catalyst and an organic solvent to contact and react in a slurry bed reactor, and carrying out solid-liquid separation treatment on the obtained mixed slurry to obtain a mixed solution containing ethylene glycol; and carrying out membrane separation treatment on the mixed solution to obtain the ethylene glycol. The method has high ethylene conversion rate and selectivity and good product purity.
The slurry bed reactor used in the present invention is also called slurry bed reactor, and refers to a reactor in which catalyst fine solid particles are suspended in a liquid medium. The material back mixing of the slurry bed reactor is large, and after the reaction is finished, the next batch of reaction can be carried out after the catalyst is separated from the material. In the slurry bed reaction, the conversion of hydrogen peroxide is high because the catalyst is mixed with the reaction mass.
The type of slurry bed reactor according to the present invention is also not particularly limited, and may be of a type conventional in the art, for example, a gas-liquid-solid three-phase fluidized bed type slurry bed reactor, preferably a bubbling slurry bed reactor. The operation mode of the slurry bed reactor is not particularly limited, and for example, the slurry bed reactor may be operated in a manner that both of the gas phase and the liquid phase are continuously fed and discharged, both of the gas phase and the liquid phase are intermittently fed and discharged, or the liquid phase is intermittently fed and discharged and the gas phase is continuously fed and discharged, or the like, wherein the gas phase and the liquid phase are preferably continuously fed and discharged, respectively.
As mentioned above, the method provided by the present invention can be operated intermittently or continuously, and the present invention has no special requirement for this. The feeding method can be any suitable method known to those skilled in the art, for example, in the case of a batch operation, the reaction can be carried out by continuously feeding ethylene and hydrogen peroxide after feeding the solvent and the catalyst into the reactor. When the reaction is carried out in a continuous mode, the catalyst and the solvent can be pulped and then ethylene and hydrogen peroxide are continuously added for reaction; the present invention has no special requirement for this, and is not described in detail herein.
According to the invention, the oxidation reaction conditions in the slurry bed reactor can be changed within a wide range, and can be reaction conditions of a conventional oxidation system using a titanium silicalite molecular sieve as a catalyst; the invention preferably uses aqueous hydrogen peroxide as the oxidizing agent to avoid the danger of gaseous hydrogen peroxide. According to one embodiment of the invention, the slurry bed reactor is operated in a continuous mode, and the conditions of the oxidation reaction may include: the molar ratio of the ethylene to the hydrogen peroxide is 1: 1-5, preferably 1: 1.1-4; the mass ratio of the organic solvent, the catalyst and the ethylene is 0.1-100: 0.001-1: 1, preferably 0.5-5: 0.01-0.4: 1; the contact temperature is 15-220 ℃, and preferably 25-80 ℃; the pressure is 0.1-8 MPa, preferably 0.5-1.8 MPa; the time is 0.1 to 20 hours, preferably 4 to 9 hours.
According to the invention, the mixed slurry obtained by the slurry bed reactor contains catalyst solid particles and reaction product ethylene glycol, and the ethylene glycol can be separated by a solid-liquid separation method. The solid-liquid separation treatment may include: one or more of solid-liquid settling separation, solid-liquid cyclone separation, filtration and solid-liquid membrane separation. For example, in one embodiment, the catalyst particles in the mixed slurry can be removed by filtration, and in another embodiment, the mixed slurry can be filtered and then subjected to a membrane separation process to further remove the catalyst fines from the mixed slurry. The solid-liquid separation may be carried out in a slurry bed reactor, for example, a solid-liquid separation module may be provided in the slurry bed reactor, and in another embodiment, the solid-liquid separation may be carried out outside the slurry bed reactor, for example, in a solid-liquid separator. The method may further comprise: carrying out solid-liquid separation on the mixed slurry through the solid-liquid separation component and/or the solid-liquid separator to obtain the mixed liquid and a solid-phase material containing catalyst particles; further, the solid phase material may be allowed to continue the reaction in the slurry bed reactor, for example, in an embodiment using a solid-liquid separation module disposed within the reactor, the solid phase material is trapped in the reactor, and the oxidation reaction is continued; in the embodiment using the solid-liquid separator provided outside the reactor, the solid-phase material obtained by the separation may be returned to the slurry bed reactor.
In a preferred embodiment, the solid-liquid separation component is a filtering component, and the filtering pore diameter of the filtering component is 30-150 μm; the solid-liquid separator is a solid-liquid membrane separator, and the membrane aperture of the solid-liquid membrane separator is less than 10 mu m; in this embodiment, the mixed slurry may be subjected to a first solid-liquid separation by passing through the filter assembly to obtain a first solid-phase material containing catalyst particles having a relatively large particle size and a first solid-liquid mixture, and the first solid-phase material may be allowed to continue to contact with the reaction material in the slurry bed reactor to perform an oxidation reaction; the first solid-liquid mixture can enter a solid-liquid membrane separator for second solid-liquid separation, catalyst particles with relatively small particle sizes are further removed, a second solid-phase material and mixed liquid containing ethylene glycol are obtained, further, in order to prevent the solid-liquid membrane separator from being blocked, the solid-liquid membrane separator can be backflushed once every 10-30 min, and the duration of each backflush can be 5-20 s.
According to the present disclosure, the mixed liquid containing ethylene glycol obtained by solid-liquid separation may be further subjected to membrane separation treatment to remove most of water; the equipment and conditions for performing the membrane separation treatment are not particularly required, and in order to further improve the product purity, in one embodiment according to the present disclosure, the membrane separation treatment may include an evaporation permeable membrane separation, and the treatment conditions of the evaporation permeable membrane separation may vary within a wide range, and preferably, the treatment conditions of the evaporation permeable membrane separation may include: the vacuum degree at the downstream side of the separation membrane can be 0.1-1.0 kPa, preferably 0.3-0.7 kPa, the temperature is 20-90 ℃, preferably 30-80 ℃, and the feeding flow rate is 50-120L/h, preferably 60-110L/h. The separation membrane used for the evaporation-permeation membrane separation is not particularly required, and is preferably a PVA membrane, or a modified PVA membrane, for example, a PVA membrane modified by grafting, blending, crosslinking, copolymerization or the like, and is more preferably a PVA/PES composite membrane, a PS composite membrane, a PAA/PVA IPN composite membrane, a PAAM/PVA IPN composite membrane, a CS/PS composite membrane, a surface-crosslinked CS/PES composite membrane, a PVP membrane, an SPE membrane, a SPEEK/PVDF composite membrane, and a microporous TiO composite membrane2In the filmMore preferably one or more of PVA film, PVA/PES composite film, PAA/PVA IPN composite film and PAAM/PVAIPN composite film. Separation membranes of the above kind are commercially available or have been developed using methods customary in the art (e.g. according to the research developments of Zea Poisson, Zhang-Pep. polyvinyl alcohol pervaporation separation membranes [ J]The university of eastern China school newspaper: the Nature science edition 2006(2) 235-240).
According to the present disclosure, the separation membrane may be assembled with filters, valves, meters, piping and other necessary elements into a membrane device for use; the form of the membrane device is not particularly limited, and is, for example, one or more of a plate-and-frame type, a circular tube type, a spiral wound type, a hollow fiber type, and a capillary type.
The aforementioned method according to the present invention can achieve the object of the present invention, and in order to further increase the conversion rate of the reactant ethylene, the amount of the surfactant is preferably 5 to 50000ppm, preferably 150 to 1000ppm, and more preferably 150 to 500ppm by weight of the organic solvent according to the present invention.
In the present invention, the object of the present invention can be achieved only by allowing a system in which ethylene, an aqueous hydrogen peroxide solution and a catalyst containing a titanium silicalite molecular sieve are contacted in an organic solvent to contain a surfactant, and specifically, there is no particular requirement on the addition manner of the surfactant, and for example, the surfactant may be added to the solvent in advance and then introduced together with the solvent, or the surfactant may be introduced last (i.e., all reactant raw materials are mixed and then added), or may be introduced after a part of the reactant raw materials are added. The object of the present invention can be achieved by any of the above-mentioned methods of introducing a surfactant, and the effects are comparable, but for simplification of the practical operation process, the surfactant is added to a liquid (e.g., an organic solvent) in advance, and then introduced into the contacted system together with the liquid.
According to the invention, the purpose of the invention can be achieved by only enabling a system in which ethylene, hydrogen peroxide and a catalyst containing a titanium silicalite molecular sieve are contacted in an organic solvent to contain a surfactant, wherein the variety of the surfactant is wide in optional range, the surfactant can be an oil-soluble surfactant or a water-soluble surfactant, and in order to further improve the selectivity of a target product, namely glycol, the surfactant is preferably selected from one or more of a Tween (Tween) surfactant, a Ninale (Ninol) surfactant, a Span (Span) surfactant, a TX-10 (alkylphenol polyoxyethylene ether) surfactant, an OP-10 (polyethylene glycol octyl phenyl ether) surfactant and an AEO-9 (fatty alcohol polyoxyethylene ether) surfactant; more preferably one or more of Tween-60 (Tween-60), Tween-80 (Tween-80), Span-60 (Span-60) and Span-80 (Span-80).
The conditions for the oxidation reaction are not particularly required in the present invention, and may be reaction conditions of a conventional oxidation system using a titanium silicalite as a catalyst, since hydrogen peroxide is easily explosive when it exists in a gaseous form, and thus it is preferable that hydrogen peroxide is supplied as an aqueous hydrogen peroxide solution in the present invention.
The concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution is not particularly limited, and for the present invention, the concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution is preferably 20 to 80% by weight, and more preferably 30 to 70% by weight. For example, 30 wt%, 50 wt%, or 70 wt% of hydrogen peroxide may be commercially available. In the invention, the catalyst containing the titanium silicalite molecular sieve can be a titanium silicalite molecular sieve. The particle size of the titanium silicalite molecular sieve can be 1000 μm or less, for example 800 μm or less, 600 μm or less, or 500 μm or less.
According to the method of the present invention, the titanium silicalite molecular sieve of the present invention may be at least one of a titanium silicalite molecular sieve of MFI structure (e.g., TS-1), a titanium silicalite molecular sieve of MEL structure (e.g., TS-2), a titanium silicalite molecular sieve of BEA structure (e.g., Ti-Beta), a titanium silicalite molecular sieve of MWW structure (e.g., Ti-MCM-22), a titanium silicalite molecular sieve of two-dimensional hexagonal structure (e.g., Ti-MCM-41, Ti-SBA-15), a titanium silicalite molecular sieve of MOR structure (e.g., Ti-MOR), a titanium silicalite molecular sieve of TUN structure (e.g., Ti-TUN), and a titanium silicalite molecular sieve of other structure (e.g., Ti.
Preferably, the titanium silicalite molecular sieve is one of a titanium silicalite molecular sieve with an MFI structure, a titanium silicalite molecular sieve with an MEL structure and a titanium silicalite molecular sieve with a BEA structureOr more, more preferably a titanium silicalite molecular sieve of MFI structure, more preferably the titanium silicalite molecular sieve is of MFI structure, the titanium silicalite molecular sieve crystal grain is of hollow structure, the radial length of the hollow cavity part of the hollow structure is 5300 nanometers, and the titanium silicalite molecular sieve is P/P at 25 DEG C0The benzene adsorption amount measured under the conditions of 0.10 and the adsorption time of 1 hour is at least 70 mg/g, and a hysteresis loop exists between the adsorption isotherm and the desorption isotherm of the low-temperature nitrogen adsorption of the titanium silicalite molecular sieve.
In the present invention, the titanium silicalite molecular sieve can be obtained commercially or prepared, and the method for preparing the titanium silicalite molecular sieve is well known to those skilled in the art and is not described herein again.
In the method according to the present disclosure, the titanium silicalite/H2O2The solvent type of the catalytic oxidation system has no special requirement, and is preferably a solvent with small steric hindrance; further, in order to improve the conversion rate and the yield of the target product, the solvent is preferably one or more of ketones, alcohols, carboxylic acids and organic alkyl halides, more preferably one or more of C3-C10 ketones, C1-C10 alcohols, C1-C10 carboxylic acids and C1-C10 organic alkyl halides; further preferred are one or more of C3-C6 ketones, C2-C6 alcohols and C1-C6 organic alkyl halides, and particularly preferred are one or more of acetone, methyl ethyl ketone, methanol, ethanol, propylene glycol, tert-butyl alcohol, acetic acid and chloroform.
In the method according to the present disclosure, the crude ethylene glycol obtained by membrane treatment may be further purified, for example, the crude ethylene glycol obtained by membrane separation treatment may be rectified to obtain ethylene glycol. In the crude product of the ethylene glycol, the content of the ethylene glycol can be 10-99 wt%, and the water content can be 0.1-90 wt%.
The operation method and conditions of the rectification may be conventional in the art, and are not particularly limited herein. For example, the ethylene glycol can be rectified by a rectifying tower under reduced pressure, the operating temperature of the rectifying tower can be 100-160 ℃, the liquid temperature in a reboiler at the bottom of the rectifying tower can be 130-180 ℃, and the tower top pressure of the rectifying tower can be 1-20 kPa; and (4) extracting a refined ethylene glycol product from the tower top. The theoretical plate number of the rectification column may be more than 50. The rectification process used may be continuous or batch.
The following examples further illustrate the invention but do not limit the scope of the invention. In the examples and comparative examples, the reagents used were all commercially available, chemically pure reagents.
The titanium silicalite molecular sieve (TS-1) catalyst used was a (TS-1) molecular sieve sample prepared as described in the literature [ Zeolite, 1992, Vol.12, pp. 943-950 ], with a titanium oxide content of 2.5 wt%.
The PVA/PS composite films used in the examples were prepared by reference methods (Bartels C R, real J. dehydration of glcols, U S Patent 4,802,988.1989);
the PAA/PVA (30/70) IPN composite membrane used in the examples was prepared by reference to literature methods (Burche M C, Sawant S B, Joshi J B, Pangakar V G, dehydrogenation of ethylene by peroxide using hydrophic IPNs PVA, PAAad PAAM membranes, Sep. purify, Tech.,1998, 13.47-56).
In the invention, the analysis of each component in the system is carried out by adopting gas chromatography, the quantification is carried out by a correction normalization method, the analysis can be carried out by referring to the prior art, and evaluation indexes such as the conversion rate of reactants, the yield and the selectivity of products and the like are calculated on the basis.
In comparative examples and examples:
example 1
Pulping solvent methanol (containing 250ppm of surfactant Tween-60 and 200ppm of span-80) and catalyst (TS-1), loading into a slurry bed reactor, and continuously adding ethylene and hydrogen peroxide into the reactor, wherein the molar ratio of the ethylene to the hydrogen peroxide is 1: 2 (hydrogen peroxide was supplied as a 30 wt% aqueous hydrogen peroxide solution, the same is true in the following examples) with a mass ratio of ethylene to catalyst of 20: 1, the mass ratio of ethylene to solvent is 1: 1.5, reacting for 3 hours at the temperature of 25 ℃ and the pressure of 0.8MPa, and then heating to 80 ℃ for reacting for 4 hours at the reaction pressure of 1.8 MPa. After the reaction is finished, filtering the mixed slurry by a filtering component in the slurry bed, leaving solid catalyst particles in the slurry bed reactor for continuous reaction, continuously feeding the solid-liquid mixture into an external solid-liquid separator for further separating the catalyst particles, and feeding the obtained mixed solution containing glycol into an evaporation and permeation membrane separator (a separation membrane is a PVA/PS composite membrane) for evaporation and permeation membrane separation, wherein the separation conditions are as follows: the temperature is 60 ℃, the feeding flow rate is 80L/h, the vacuum degree on the downstream side of the separation membrane is 0.4kPa, a crude ethylene glycol product is obtained, then the crude ethylene glycol product enters a rectifying tower for rectification, the purity is 99%, the ethylene conversion rate is 99.2%, and the ethylene glycol selectivity is 98.6%.
Example 2
Pulping a mixed solvent of trichloromethane and methanol (the molar ratio of trichloromethane to methanol is 1:5, and 150ppm of surfactant Tween-60 and 150ppm of span-80) and a catalyst (TS-1), then loading the mixture into a slurry bed reactor, and continuously adding ethylene and hydrogen peroxide into the reactor, wherein the molar ratio of the ethylene to the hydrogen peroxide is 1:1.1 (hydrogen peroxide in 30% by weight aqueous hydrogen peroxide) with a mass ratio of ethylene to catalyst of 10: 1, the mass ratio of ethylene to solvent is 1:5, reacting for 2 hours at the temperature of 35 ℃ and the pressure of 1.0MPa, and then heating to 65 ℃ for reacting for 5 hours at the reaction pressure of 1.6 MPa. After the reaction is finished, filtering the mixed slurry obtained by the reaction by a filtering component in the slurry bed, leaving solid catalyst particles in the slurry bed reactor for continuous reaction, continuously feeding the solid-liquid mixture into an external solid-liquid separator for further separating out the catalyst particles, feeding the obtained mixed solution containing the ethylene glycol into an evaporation and permeation membrane separator (the separation membrane is a PVA/PS composite membrane) for evaporation and permeation membrane separation, wherein the separation conditions are as follows: the temperature is 60 ℃, the feeding flow rate is 80L/h, the vacuum degree on the downstream side of the separation membrane is 0.4kPa, a crude ethylene glycol product is obtained, then the crude ethylene glycol product enters a rectifying tower for rectification, the purity is 99%, the ethylene conversion rate is 98.7%, and the ethylene glycol selectivity is 99.5%.
Example 3
Pulping acetone (containing 200ppm of surfactants Tween-80 and 150ppm of TX-10) and a catalyst (TS-1), then loading the mixture into a slurry bed reactor, and continuously adding ethylene and hydrogen peroxide into the reactor, wherein the molar ratio of the ethylene to the hydrogen peroxide is 1: 3 (hydrogen peroxide in 30% by weight aqueous hydrogen peroxide) with a mass ratio of ethylene to catalyst of 50: 1, the mass ratio of ethylene to solvent is 1: 3, reacting for 3 hours at the temperature of 40 ℃ and the pressure of 0.5MPa, and then heating to 55 ℃ for reacting for 6 hours, wherein the reaction pressure is 1.4 MPa. After the reaction is finished, filtering the mixed slurry obtained by the reaction by a filtering component in the slurry bed, leaving solid catalyst particles in the slurry bed reactor for continuous reaction, continuously feeding the solid-liquid mixture into an external solid-liquid separator for further separating out the catalyst particles, feeding the obtained mixed solution containing the ethylene glycol into an evaporation and permeation membrane separator (the separation membrane is a PVA/PS composite membrane) for evaporation and permeation membrane separation, wherein the separation conditions are as follows: the temperature is 60 ℃, the feeding flow rate is 80L/h, the vacuum degree on the downstream side of the separation membrane is 0.4kPa, a crude ethylene glycol product is obtained, then the crude ethylene glycol product enters a rectifying tower for rectification, the purity is 99%, the ethylene conversion rate is 99.3%, and the ethylene glycol selectivity is 98.4%.
Example 4
Pulping methanol (containing 150ppm of Ethylene Oxide (EO) and 150ppm of span-80) and a catalyst (TS-1), then loading the mixture into a slurry bed reactor, and continuously adding ethylene and hydrogen peroxide into the reactor, wherein the molar ratio of the ethylene to the hydrogen peroxide is 1:5 (hydrogen peroxide in 30% by weight aqueous hydrogen peroxide) with a mass ratio of ethylene to catalyst of 100: 1, the mass ratio of ethylene to solvent is 1: 0.5, reacting for 2 hours at the temperature of 30 ℃ and the pressure of 1.0MPa, and then heating to 65 ℃ for reacting for 4 hours at the reaction pressure of 1.8 MPa. After the reaction is finished, filtering the mixed slurry obtained by the reaction by a filtering component in the slurry bed, leaving solid catalyst particles in the slurry bed reactor for continuous reaction, continuously feeding the solid-liquid mixture into an external solid-liquid separator for further separating out the catalyst particles, feeding the obtained mixed solution containing the ethylene glycol into an evaporation and permeation membrane separator (the separation membrane is a PVA/PS composite membrane) for evaporation and permeation membrane separation, wherein the separation conditions are as follows: the temperature is 60 ℃, the feeding flow rate is 80L/h, the vacuum degree on the downstream side of the separation membrane is 0.4kPa, a crude ethylene glycol product is obtained, then the crude ethylene glycol product enters a rectifying tower for rectification, the purity is 99%, the ethylene conversion rate is 98%, and the ethylene glycol selectivity is 97.8%.
Example 5
Pulping a mixed solvent of trichloromethane and methanol (the molar ratio of the trichloromethane to the methanol is 1: 10, and 150ppm of surfactant Tween-60 and 250ppm of Ninale) and a catalyst (TS-1), then loading the mixture into a slurry bed reactor, and continuously adding ethylene and hydrogen peroxide into the reactor, wherein the molar ratio of the ethylene to the hydrogen peroxide is 1: 1.5 (hydrogen peroxide in 70% by weight aqueous hydrogen peroxide) with a mass ratio of ethylene to catalyst of 80: 1, the mass ratio of ethylene to solvent is 1: 1.2, reacting for 2 hours at the temperature of 35 ℃ and the pressure of 1.0MPa, and then heating to 55 ℃ for reacting for 4 hours at the reaction pressure of 1.7 MPa. After the reaction is finished, filtering the mixed slurry obtained by the reaction by a filtering component in the slurry bed, leaving solid catalyst particles in the slurry bed reactor for continuous reaction, continuously feeding the solid-liquid mixture into an external solid-liquid separator for further separating out the catalyst particles, feeding the obtained mixed solution containing the ethylene glycol into an evaporation and permeation membrane separator (the separation membrane is a PVA/PS composite membrane) for evaporation and permeation membrane separation, wherein the separation conditions are as follows: the temperature is 60 ℃, the feeding flow rate is 80L/h, the vacuum degree on the downstream side of the separation membrane is 0.4kPa, a crude ethylene glycol product is obtained, then the crude ethylene glycol product enters a rectifying still for rectification, the purity is 99%, the ethylene conversion rate is 99.6%, and the ethylene glycol selectivity is 97%.
Example 6
The same procedure as in example 1, except that Ti-MCM-41 (3% titania as prepared by the method described in Corma et al, chem. Commun.,1994,147-148, of the prior art) was used in place of TS-1, the ethylene conversion was 99.6%, the ethylene glycol selectivity was 97%, and the ethylene glycol product purity was 99%.
Example 7
The same procedure as in example 1, except that Ti-Beta (prepared as described in TakashiTasumi et al, J.Chem.Soc., Chem.Commun.1997, 677-678, titanium oxide content 2.6%) was used in place of TS-1, ethylene conversion was 99.6%, ethylene glycol selectivity was 97%, and ethylene glycol product purity was 99%.
Example 8
The same procedure as in example 1 was followed, except that the molar ratio of ethylene to hydrogen peroxide was 1: 5. The conversion rate of ethylene is 99.4%, the selectivity of ethylene glycol is 95.3%, and the purity of ethylene glycol product is 98.7%.
Example 9
The same procedure as in example 1 was followed, except that a PAA/PVA (30/70) IPN composite membrane was used. The conversion rate of ethylene is 99.2%, the selectivity of ethylene glycol is 98.6%, and the purity of ethylene glycol product is 98.9%.
Comparative example 1
The same procedure as in example 1 was followed, except that the solvent contained no surfactant, the ethylene conversion was 83%, the ethylene glycol selectivity was 56%, and the product was not further isolated and purified.
Comparative example 2
The same procedure as in example 1, except that no solvent and surfactant were added, the ethylene conversion was 63%, the ethylene glycol selectivity was 32%, and the product was not further isolated and purified.
Comparative example 3
The same procedure as in example 1, except that no solvent was added, the ethylene conversion was 67%, the ethylene glycol selectivity was 47%, and the product was not further isolated and purified.
Comparative example 4
The procedure of example 1 was repeated, except that the mixed solution containing ethylene glycol obtained by solid-liquid separation was fed directly to the rectifying column without membrane separation treatment and subjected to rectification treatment. The conversion rate of ethylene is 99.2%, the selectivity of ethylene glycol is 98.6%, and the purity of ethylene glycol product is 96%.
From the above examples and comparative example data, it can be seen that the ethylene conversion rate and selectivity of the present disclosure prepared by the method of performing a reaction in a slurry bed reactor using a titanium silicalite molecular sieve/hydrogen peroxide system are high, and the method uses a membrane separation treatment to obtain a mixed slurry, and the obtained ethylene glycol product has good purity, and does not need to use conventional separation equipment such as a rectifying tower for product separation.
The preferred embodiments of the present disclosure have been described in detail above, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.
It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.
In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.
Claims (14)
1. A method for preparing ethylene glycol by oxidizing ethylene, wherein the method comprises the following steps: under the condition of oxidation reaction, in the presence of a surfactant, enabling ethylene, aqueous hydrogen peroxide, a catalyst containing a titanium silicalite molecular sieve and an organic solvent to contact and react in a slurry bed reactor, and carrying out solid-liquid separation treatment on the obtained mixed slurry to obtain a mixed solution containing ethylene glycol; subjecting the mixed solution to membrane separation treatment.
2. The method of claim 1, wherein the slurry bed reactor is operated continuously; the conditions of the oxidation reaction include: the molar ratio of the ethylene to the hydrogen peroxide is 1: 1-5, preferably 1: 1.1-4; the mass ratio of the organic solvent, the catalyst and the ethylene is 0.1-100: 0.001-1: 1, preferably 0.5-5: 0.01-0.4: 1; the contact temperature is 15-220 ℃, and preferably 25-80 ℃; the pressure is 0.1-8 MPa, preferably 0.5-1.8 MPa; the time is 0.1 to 20 hours, preferably 4 to 9 hours.
3. The method according to claim 1 or 2, wherein the concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution is 20 to 80 wt. -%, preferably 30 to 70 wt. -%.
4. The method of claim 1, wherein the slurry bed reactor is a gas-liquid-solid three-phase slurry bed reactor.
5. The method of claim 1, wherein the solid-liquid separation treatment comprises: one or more of solid-liquid settling separation, solid-liquid cyclone separation, filtration and solid-liquid membrane separation.
6. The method of claim 1 or 5, wherein a solid-liquid separation assembly is provided within the slurry bed reactor; and/or the outlet of the slurry bed reactor is communicated with a solid-liquid separator;
the method further comprises the following steps: carrying out solid-liquid separation on the mixed slurry through the solid-liquid separation component and/or the solid-liquid separator to obtain the mixed liquid and a solid-phase material containing catalyst particles; continuing the reaction with the solid phase feed in the slurry bed reactor.
7. The method according to claim 6, wherein the solid-liquid separation module is a filter module, and the filter module has a filter pore size of 30-150 μm; the solid-liquid separator is a solid-liquid membrane separator, and the membrane aperture of the solid-liquid membrane separator is less than 10 mu m;
the method comprises the following steps: carrying out first solid-liquid separation on the mixed slurry through the filtering component to obtain a first solid-phase material and a first solid-liquid mixture, and continuing the reaction of the first solid-phase material in the slurry bed reactor; and enabling the first solid-liquid mixture to enter the solid-liquid membrane separator for second solid-liquid separation to obtain a second solid-phase material and the mixed liquid.
8. The method of claim 1, wherein the membrane separation process comprises an evaporation permeable membrane separation process conditions comprising: the vacuum degree at the downstream side of the separation membrane is 0.3-0.7 kPa, the temperature is 20-90 ℃, and the feeding flow rate is 50-120L/h.
9. The method according to claim 8, wherein the separation membrane used in the evaporation-permeation membrane separation is a PVA membrane, a PVA/PES composite membrane, a PS composite membrane, a PAA/PVA IPN composite membrane, a PAAM/PVA IPN composite membrane, a CS/PS composite membrane, a surface-crosslinked CS/PES composite membrane, a PVP membrane, an SPE membrane, a SPEEK/PVDF composite membrane, or a microporous TiO2One or more of the membranes.
10. The method according to claim 1, wherein the amount of the surfactant is 5 to 50000ppm by weight of the organic solvent; the surfactant is selected from one or more of Tween surfactant, Ninale surfactant, span surfactant, TX-10 surfactant, OP-10 surfactant and AEO-9 surfactant.
11. The method of claim i, wherein the catalyst comprising titanium silicalite is a titanium silicalite; the titanium silicalite molecular sieve is at least one of a titanium silicalite molecular sieve with an MFI structure, a titanium silicalite molecular sieve with an MEL structure, a titanium silicalite molecular sieve with a BEA structure, a titanium silicalite molecular sieve with an MWW structure, a titanium silicalite molecular sieve with an MOR structure, a titanium silicalite molecular sieve with a TUN structure and a titanium silicalite molecular sieve with a two-dimensional hexagonal structure.
12. The method of claim 11, wherein the titanium silicalite molecular sieve is of MFI structure, the crystallites are of hollow structure, the radial length of the hollow cavity part of the hollow structure is 5-300 nm, and the P/P of the titanium silicalite molecular sieve is at 25 ℃0The benzene adsorption amount measured under the conditions of 0.10 and the adsorption time of 1 hour is at least 70 mg/g, and a hysteresis loop exists between the adsorption isotherm and the desorption isotherm of the low-temperature nitrogen adsorption of the titanium silicalite molecular sieve.
13. The method of claim i, wherein the organic solvent is one or more of a C3-C10 ketone, a C1-C10 alcohol, a C1-C10 carboxylic acid, and a C1-C10 organohaloalkane.
14. The method of claim l, wherein the method further comprises: and rectifying the ethylene glycol crude product obtained by the membrane separation treatment to obtain the ethylene glycol.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911176887.9A CN112851477A (en) | 2019-11-26 | 2019-11-26 | Method for preparing ethylene glycol by ethylene oxidation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911176887.9A CN112851477A (en) | 2019-11-26 | 2019-11-26 | Method for preparing ethylene glycol by ethylene oxidation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112851477A true CN112851477A (en) | 2021-05-28 |
Family
ID=75985803
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911176887.9A Pending CN112851477A (en) | 2019-11-26 | 2019-11-26 | Method for preparing ethylene glycol by ethylene oxidation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112851477A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102951998A (en) * | 2011-08-24 | 2013-03-06 | 岳阳蓬诚科技发展有限公司 | Method of preparing glycol by using one-step ethylene method |
| CN103012064A (en) * | 2011-09-28 | 2013-04-03 | 中国石油化工股份有限公司 | Method for preparing propylene glycol from propylene |
| CN105001058A (en) * | 2014-12-12 | 2015-10-28 | 北京恩泽福莱科技有限公司 | Method for preparing glycol from ethene |
-
2019
- 2019-11-26 CN CN201911176887.9A patent/CN112851477A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102951998A (en) * | 2011-08-24 | 2013-03-06 | 岳阳蓬诚科技发展有限公司 | Method of preparing glycol by using one-step ethylene method |
| CN103012064A (en) * | 2011-09-28 | 2013-04-03 | 中国石油化工股份有限公司 | Method for preparing propylene glycol from propylene |
| CN105001058A (en) * | 2014-12-12 | 2015-10-28 | 北京恩泽福莱科技有限公司 | Method for preparing glycol from ethene |
Non-Patent Citations (1)
| Title |
|---|
| 郭瑞丽: "新型渗透蒸发膜分离乙二醇水溶液", 《中国优秀博硕士学位论文全文数据库（博士）工程科技I辑》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101641343B (en) | Propylene oxide recovery process | |
| CN107961814B (en) | Reduction method of catalyst for preparing propylene oxide by propylene epoxidation, catalyst and application | |
| CN101730687A (en) | Method for producing propylene oxide | |
| KR20190004322A (en) | Preparation method of oligosilane | |
| CN113979855B (en) | Preparation method of crotonic acid | |
| CN109651308A (en) | A kind of purification process of 5 hydroxymethyl furfural | |
| CN109153588B (en) | Method for treating waste water | |
| CN102951998A (en) | Method of preparing glycol by using one-step ethylene method | |
| CN107867996B (en) | Method for separating levulinic acid compounds | |
| KR100594482B1 (en) | Membrane filtration | |
| CN109153015B (en) | Method for preparing catalyst and use thereof | |
| CN112851477A (en) | Method for preparing ethylene glycol by ethylene oxidation | |
| CN108126664B (en) | Modified molecular sieve for purifying olefin and method for removing oxygen-containing impurities in olefin by using modified molecular sieve | |
| CN111072598B (en) | Process for producing epichlorohydrin by direct oxidation of titanium-silicon molecular sieve catalyst | |
| JP2023516850A (en) | Method for synthesizing 2,5-furandicarboxylic acid | |
| CN103373977B (en) | Oxidation reaction method of cyclic ketone compound | |
| US11851354B2 (en) | Process for the treatment of waste water | |
| CN113956150B (en) | Preparation method of glyceric acid | |
| CA3101904A1 (en) | Salt and acid mixture catalyzed 5-hydroxymethylfurfural (hmf) production | |
| CN113968829B (en) | Propylene epoxidation method and epoxidation system | |
| Lee et al. | An experimental study on the application of polymer membranes to the catalytic decomposition of MTBE (methyl tert.-butyl ether) | |
| CN103373975A (en) | Oxidation method of cycloparaffin | |
| CN108794359B (en) | Method for producing dimethyl sulfoxide from hydrogen sulfide | |
| EP2628736A1 (en) | Refining method for crude propylene oxide product and preparation method for propylene oxide | |
| JP7284692B2 (en) | Method for producing aromatic alcohol |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |