CN113527047A

CN113527047A - Process for co-producing trans-HFO-1234 ze and cis-HFO-1234 ze

Info

Publication number: CN113527047A
Application number: CN202010320753.6A
Authority: CN
Inventors: 权恒道; 杨会娥; 张迪; 欧阳洪生; 刘冬鹏; 谢品赞
Original assignee: Shaanxi Zhonglan Chemical Technology New Material Co ltd; Zhejiang Chemical Industry Research Institute Co Ltd; Sinochem Lantian Co Ltd
Current assignee: Shaanxi Zhonglan Chemical Technology New Material Co ltd; Zhejiang Chemical Industry Research Institute Co Ltd; Sinochem Lantian Co Ltd
Priority date: 2020-04-22
Filing date: 2020-04-22
Publication date: 2021-10-22

Abstract

The invention relates toVinyl Chloride (CH)₂CHCl) and carbon tetrachloride (CCl)₄) A process for the production of transHFO-1234 ze and cis HFO-1234ze as starting materials. Vinyl Chloride (CH)₂CHCl) and carbon tetrachloride (CCl)₄) Synthesizing 1,1,1,3, 3-pentachloropropane (HCC-240fa) by telomerization in a catalytic system composed of a chlorinated metal salt/molecular sieve catalyst and N, N-dimethylethylamine, separating HCC-240fa by rectification, performing fluorination reaction in a second reactor, and performing fluorination reaction in a third reactor by using alumina as a catalyst carrier₂O₃And alpha-Al₂O₃Under the action of isomerization catalyst of mixed crystal phase making isomerization reaction to convert trans-HFO-1234 ze into cis-HFO-1234 ze, finally making said product pass through multistage separation tower to make extraction separation so as to obtain trans-HFO-1234 ze and cis-HFO-1234 ze products.

Description

Process for co-producing trans-HFO-1234 ze and cis-HFO-1234 ze

Technical Field

The invention relates to a preparation process of trans-HFO-1234 ze and cis-HFO-1234 ze, in particular to a method for preparing trans-HFO-1234 ze and cis-HFO-1234 ze from Chloroethylene (CH)₂CHCl) and carbon tetrachloride (CCl)₄) A process for the production of transHFO-1234 ze and cis HFO-1234ze as starting materials.

Background

Chlorofluorocarbons are widely used in refrigerants, blowing agents and cleaning agents for refrigerators, air conditioners and the like. In recent years, the protection of the ozone layer has been the focus of global attention, and chlorofluorocarbon gases have been increasingly used in a limited manner due to the destruction of the atmospheric ozone layer and the greenhouse effect. 1,3,3, 3-tetrafluoropropene has a lower greenhouse potential and zero ozone depletion potential. The foaming agent is considered as one of new-generation refrigerants, is also considered as the most promising next-generation foaming agent, is also used as a cleaning agent, an aerosol propellant, a solvent composition, an insulating material and a fire extinguishing and suppressing agent, can be used as a coating material and a high-temperature-resistant acid-resistant heat-insulating material, is widely applied to fire protection, aerospace, aviation and the like, and has wide application prospect.

The raw materials and routes for synthesizing 1,3,3, 3-tetrafluoropropene mainly comprise the following components: HFC-245fa and 1-chloro-3, 3, 3-trifluoropropene (HCFO-1233zd) are used as raw materials for synthesis, so that the yield is high, the selectivity is good, but the raw materials are expensive, the requirement on equipment is high, the process is complex, the economy is poor, and the industrial production is not facilitated. HFC-245eb is taken as a raw material, the method mostly adopts the process of taking 1,1,1,2, 3-pentafluoropropane (HFC-245eb) as the raw material to coproduce HFO-1234ze and HFO-1234yf, the obtained product is mainly HFO-1234yf, and the selectivity of HFO-1234ze is very low. The synthesis route using halogenated methane and halogenated ethylene as raw materials or the synthesis route using trifluoropropene as raw materials has the advantages of complex process, more byproducts, low conversion rate and no industrial production value. HFC-240fa is 1,1,1,3, 3-pentachloropropane, and the

target product

1,3,3, 3-tetrafluoropropene is obtained by a fluorination method. HFC-240fa can be synthesized from ethylene or vinyl chloride, has easily available raw materials, low cost and easy industrial production, but the selectivity of HFO-1234ze needs to be improved.

Patent CN1911512B, the institute of industrial and technical integration of independent administration, japan, relates to a fluorination catalyst obtained by treating a metal salt containing a chromium salt such as chromium oxide with chlorine gas and/or oxygen gas. 1,1,1,3, 3-pentachloropropane and hydrogen fluoride are reacted in the gas phase using a catalyst that can be efficiently converted to 1-chloro-3, 3, 3-trifluoropropene and 1,3,3, 3-tetrafluoropropene. The catalyst has excellent catalytic activity or selectivity for 1,1,1,3, 3-pentafluoropropane (HFC-245fa), the selectivity is up to 92.6 percent, and the yield of trans-1, 3,3, 3-tetrafluoropropene, namely trans-HFO-1234 ze, is only 7-8 percent.

CN101215220A of the Seaman recent chemical research institute relates to a preparation method for obtaining 1,1,1, 3-tetrafluoropropene by gas-phase catalytic fluorination of 1,1,1,3, 3-pentachloropropane (HCC-240 fa). The product is obtained by adopting a chromium-based fluorination catalyst through distillation separation, deacidification, dehydration, rectification and purification processes.

JP3821514B2 of central Nitri, Japan, relates toHCC-240fa is taken as raw material and is carried out at the temperature of 400-600 ℃ and 1-10kg/cm in the presence of fluorination catalyst²A process for the preparation of HFO-1234ze by gas phase reaction under pressure. The catalyst is active carbon supported oxide, (oxy) fluoride, (oxy) chloride or (oxy) fluorochlorides of metals, and the metals are Cr, Ti, Al, Mn, Ni or Co.

CN103476736B to hounwell discloses a fully integrated process for the preparation of 1,1,1,3, 3-pentafluoropropane (HFC-245fa), trans-1-chloro-3, 3, 3-trifluoropropene, and trans-1, 3,3, 3-tetrafluoropropene. The raw material is 1,1,1,3, 3-pentachloropropane (HCC-240fa) and excess anhydrous HF which react in a liquid phase reactor in the presence of a catalyst, HCFO-1233zd and HFO-1234ze and excess HCl are converted into HCFC-243fa and HCFC-244fa respectively in the presence of the catalyst for separation between 245fa and trans-HCFO-1233 zd with approximate boiling points, and then HCFO-1233zd and HFO-1234ze are prepared respectively through dehydrochlorination reaction after separation.

As can be seen, HCFO-1233zd or 1,1,1,3, 3-pentachloropropane (HCC-240fa) is mostly used as a reaction raw material in the current related research. Has the problems of high raw material cost, low conversion rate and the like, and is difficult to realize industrial production. The invention provides a new method for preparing vinyl Chloride (CH)₂CHCl) and carbon tetrachloride (CCl)₄) A process for the production of trans-HFO-1234 ze and cis-HFO-1234 ze as starting materials. With vinyl Chloride (CH)₂CHCl) and carbon tetrachloride (CCl)₄) Synthesizing 1,1,1,3, 3-pentachloropropane (HCC-240fa) by telomerization in a catalytic system composed of chlorinated metal salt/molecular sieve catalyst and N, N-dimethylethylamine, separating HCC-240fa by rectification, performing fluorination reaction in a second reactor, and preparing catalyst carrier of alumina containing theta-Al₂O₃And alpha-Al₂O₃Under the action of isomerization catalyst of mixed crystal phase making isomerization reaction to convert trans-HFO-1234 ze into cis-HFO-1234 ze, making said trans-HFO-1234 ze pass through multistage separation tower, extracting and separating so as to obtain trans-HFO-1234 ze and cis-HFO-1234 ze products.

Disclosure of Invention

In view of the above problems, the present invention provides a CH₂CHCl and

CCl

₄1,1,1,3, 3-pentachloropropane (HCC-240fa) is produced as a raw material, andfurther process for the preparation of HFO-1234 ze.

The technical scheme adopted by the invention for achieving the aim is as follows:

step (1), CH₂CHCl and CCl₄The formed feed stream (1) is synthesized into 1,1,1,3, 3-pentachloropropane (HCC-240fa) by telomerization in a first reactor.

The reaction process is mature, the production process is safe and environment-friendly, and the raw materials can be recycled. The selection of the catalyst is crucial, and the catalytic performance is the key to determine the production efficiency and whether the industrial production can be realized.

Side reactions inevitably occur in telomers, and chlorine-containing olefinic compounds containing double bonds are mostly formed as by-products. The proper catalyst can improve the selectivity of the target product and control the occurrence of side reaction. The catalyst system used for the reaction mainly comprises a Cu-system catalyst and a Fe-system catalyst, wherein the Cu-system catalyst comprises cuprous, copper halide and an organic copper complex, and the Fe-system catalyst comprises Fe powder and ferrous halide.

The invention prepares a chlorinated metal salt/molecular sieve catalyst through a plurality of research experiments, the chlorinated metal salt/molecular sieve catalyst and N, N-dimethylethylamine form a catalytic system together, and the catalyst chlorinated metal salt/molecular sieve is counted by chlorinated metal salt, CH₂The molar ratio of the CHCl to the chlorinated metal salt is 1: 0.1-0.8, preferably 1: 0.1-0.3, and the molar ratio of the chlorinated metal salt to the N, N-dimethylethylamine is 1: 1.5-5, preferably 1: 2.5-4 in terms of the chlorinated metal salt. N, N-dimethylethylamine can be subjected to metal amine complexation with a part of chlorinated metal salt, so that the activity of the catalyst is improved, and the problems of blockage of a reaction instrument pipeline, difficulty in recycling the catalyst and the like caused by the generation of viscous organic amine salt in the reaction process due to the conventional cocatalyst triethanolamine are effectively solved. The chloridized metal salt/molecular sieve catalyst and N, N-dimethylethylamine form a catalytic system together for applying to liquid-phase CH₂CHCl and CCl₄The selectivity of HCC-240fa reaches 99.4% and the yield of HCC-240fa is obviously improved.

The preparation method of the chlorinated metal salt/molecular sieve catalyst comprises the following steps: the catalyst is synthesized by using a chloride metal salt as an active component, preferably at least one metal selected from magnesium, iron, copper, calcium and palladium, more preferably copper as an active component, and using a molecular sieve as a carrier, wherein the molecular sieve can be at least one selected from 3A, 4A, 5A and 13X molecular sieves, more preferably 13X molecular sieves. Firstly adding deionized water into metal chloride, stirring and dissolving to obtain a metal salt solution, then adding a molecular sieve carrier, soaking at room temperature for 8-12 h, filtering, then placing in a drying oven, drying at 110-120 ℃ for 8-13 h, and roasting at 500 ℃ for 5h to obtain the catalyst.

The reaction adopts acetonitrile as solvent, and adopts CCl₄、CH₂A catalytic system formed by CHCl, a chlorinated metal salt/molecular sieve catalyst and N, N-dimethylethylamine is mixed under the action of polar aprotic solvent acetonitrile, and CCl₄Generate carbonium ions to attack alkenyl carbon and generate electrophilic addition reaction to obtain the product.

In CH₂CHCl and CCl₄In terms of the amount of (C), usually CCl₄Excess, CCl₄Too low a relative proportion of (A) will affect the reactor efficiency, whereas CCl₄The large excess will increase the burden on the separation distillation system. Therefore, it is necessary to select an appropriate CH₂CHCl and CCl₄And (4) proportion. The CH is determined by selecting and comparing a plurality of experiments₂CHCl and CCl₄The molar ratio is 1: 1.5-8, preferably 1: 2-6.

With CH₂CHCl as raw material, through CCl₄And CH₂The telomerization of CHCl produces HCC-240 fa. In the first reactor (1), the feedstock CCl is introduced₄Is prepared from CH₂CHCl into CCl₄Then adding a metal chloride salt/molecular sieve catalyst, reacting with N, N-dimethylethylamine and acetonitrile solvent, introducing inert gas such as nitrogen, helium and argon, controlling the temperature to be 110-170 ℃, preferably 130-150 ℃, and the reaction pressure to be 0.4-1.1Mpa, and reacting.

And (2) separating by a rectifying tower to obtain a

product

1,1,1,3, 3-pentachloropropane (HCC-240 fa).

The material (2) after the reaction in the first reactor contains HCC-240fa, catalyst and few high-boiling-point substanceProduct (mainly containing chlorine-containing olefin) and excessive CCl₄Directly enters the first separation tower. The material coming out of the top of the first separation tower is CCl which is not completely reacted₄Can be directly used as a reaction raw material to continue the reaction, and the reaction raw material is returned to the reaction kettle to be recycled to the reactor. The bottom of the first separation column produces a mixture (3) containing HCC-240fa, catalyst and high boiler by-products, which is passed to a separator to separate the catalyst and a stream rich in HCC-240 fa. The catalyst is collected and then is treated separately and recycled. The stream rich in HCC-240fa enters the second separation column. The target product HCC-240fa (4) is obtained from the top of the second separation column, and very little high-boiling by-product is obtained from the bottom discharge.

Wherein the temperature of the tower kettle of the first separation tower is 90-150 ℃, preferably 90-120 ℃, and the pressure is 0.05-0.1 MPa, preferably 0.08-0.1 MPa. The temperature of the tower kettle of the second separation tower is 40-90 ℃, preferably 45-75 ℃, and the pressure is 0.07-0.12 MPa, preferably 0.08-0.1 MPa.

And (3) feeding a target product HCC-240fa (4) obtained at the top of the second separation tower into a second reactor, introducing anhydrous HF, and performing a fluorination reaction under the action of a fluorination catalyst.

The reaction temperature is preferably 200-250 ℃, the reaction pressure is preferably 0.2-0.8 MPa, the molar ratio of HF to HCC-240fa is preferably 3: 1-18: 1, and the space velocity is preferably 300-1000 h^-1. In a more preferable mode, in the second reactor, the reaction temperature is 180-260 ℃, the reaction pressure is 0.2-0.5 MPa, the molar ratio of HF to HCC-240fa is 6: 1-18: 1, and the space velocity is 300-800 h^-1。

Fluorination catalysts include chromium, aluminum, cobalt, manganese, nickel and iron oxides, hydroxides, halides, inorganic salts and mixtures thereof. Preferably an iron-containing chromium oxyfluoride catalyst; in the iron-containing chromium oxyfluoride catalyst, the mass percent of chromium in the active metal is preferably 70-90%; preferably, the iron-containing chromium oxyfluoride catalyst may further comprise other active metals, preferably one, two or three of Mg, Zn, Al, Pt, Pd and La.

Preferably, the catalyst is fluorinated prior to use, preferably using HF. The specific pretreatment mode is to place the fluorination catalyst in a catalyst reactor, and introduce HF-inert gas with the molar ratio of 3-8:1, preferably 5-7: 1, preferably with an inert gas such as nitrogen, helium, argon, mixed with HF. And (3) fluorination treatment at 180-380 ℃, preferably 240-360 ℃, for 15-400 minutes, preferably 140-220 minutes.

The catalyst needs to be in sufficient, even excess, to achieve optimal selectivity and conversion. The catalyst may be in the form of, for example, spheres, tablets, or granules, without limitation to physical form.

And (4) enabling the reaction product (5) in the second reactor to enter a third reactor to perform isomerization reaction: the trans-HFO-1234 ze is converted to cis-HFO-1234 ze as follows:

preferably, the isomerization reaction is carried out under the action of an isomerization catalyst; the reaction temperature of the third reactor is 150-^-1The isomerization reaction is carried out in the gas phase. The reaction temperature is more preferably 200-350 ℃, the reaction pressure is more preferably 0.1-0.6MPa, and the space velocity of the raw materials is more preferably 500-1000h^-1。

The isomerization catalyst carrier is prepared by taking aluminum isopropoxide as an aluminum source. The specific surface area of the catalyst carrier is 10-20m²(ii)/g, the average pore diameter is 20-30 nm. The pore size distribution of the catalyst carrier is concentrated, and more than 80 percent of the pore size is 15-35 nm. Preferably, more than 90% of the pores have a diameter of 15-35 nm. After isomerization reaction, the crystal form of the catalyst carrier is unchanged. The catalyst carrier has high stability.

The preparation of the catalyst carrier specifically comprises the following steps: adding aluminum isopropoxide into ethylene glycol to prepare an aluminum solution with the aluminum content of 0.5-2mol/L, then treating at 120-180 ℃ for 12-48 hours, centrifugally separating, washing a sample obtained by centrifugal separation with absolute ethyl alcohol, drying in air at 40-70 ℃ for 10-24 hours to obtain powder, and roasting the powder in an air atmosphere at 1000-1500 ℃ for 1-5 hours to obtain the product containing theta-Al₂O₃And alpha-Al₂O₃A catalyst support of mixed crystal phases.

The crystal structure of the catalyst carrier prepared by the invention is stable, and the crystal structure is very suitable for isomerization reaction of transHFO-1234 ze. The carrier surface has few acid-base centers, the L acid strength is proper, the anti-carbon deposition capability is good, and the selectivity to the trans-HFO-1234 ze isomerization reaction is high.

The carrier is the main component of trans HFO-1234ze isomerization catalyst and is also an important factor influencing the performance of the catalyst. The carrier is very suitable for loading active components, and has excellent dispersing performance on the active components. The catalyst comprising active components and the carrier of the invention is adopted to carry out trans-HFO-1234 ze isomerization reaction, thus realizing the metal-acid synergistic effect, having high reaction conversion rate, good stability and strong anti-carbon deposition capability, obviously reducing side reaction and obviously reducing the generation of byproduct HFC-245 fa.

The active component of the transHFO-1234 ze isomerization catalyst is composed of one or more of VIII group metal and IB group metal elements, preferably one or more of Fe, Co, Ni, Ru, Rh, Pd, Pt, Cu, Ag and Au, and further preferably Pd, Cu and/or Fe. Optionally, the active component is Pd. Optionally, the active component is Fe. In the preparation process of the catalyst, the raw materials of the active component are preferably chlorides, carbonates, nitrates, acetates and sulfates corresponding to the metals of the active component.

transHFO-1234 ze isomerization catalysts may also include doping components and/or promoters.

The doping component is composed of one or more of alkali metal and alkaline earth metal elements, preferably one or more of Na, K, Mg, Ca, Sr and Ba, and further preferably at least one of Ca, Mg and Sr. Optionally, the doping component is Ca. Optionally, the doping component is Sr. The doping component may be an oxide, fluoride, hydroxide of Na, K, Mg, Ca, Sr or Ba, preferably an oxide. The function of the doping component is to adjust the acidity and the acid amount of the carrier, particularly to reduce the number of strong Lewis acid sites on the carrier, so that the generation amount of HFC-245fa can be further reduced.

The auxiliary agent is composed of one or more alkali metals, preferably at least one selected from K, Cs and Na. Optionally, the adjuvant is K. Optionally, the adjuvant is Cs. The assistant can act synergistically with the carrier, the active component and the doping component, effectively reduce the Lewis acidity of the catalyst, promote the high dispersion of the metal active center and the interaction between the carriers, obviously reduce the side reaction in the gas phase isomerization process of the trans-HFO-1234 ze, reduce carbon deposition and improve the stability.

In the trans-HFO-1234 ze isomerization catalyst, the mass percentage of the carrier, the active component, the doping component and the auxiliary agent of the catalyst is 1 (0.001-0.2): (0-0.2), preferably 1 (0.01-0.1): (0-0.15), more preferably 1 (0.01-0.05): (0.001-0.1): 0.001-0.1).

The catalyst used in the present invention may be prepared according to methods commonly used in the art, such as impregnation, precipitation and mechanical mixing, to achieve the combination of the support, active ingredient and auxiliary agent.

Preferably, the catalyst used in the present invention may be subjected to an activation treatment before use. The method for activating the catalyst comprises the steps of loading the prepared catalyst into a reaction area, and carrying out hydrogen reduction and/or nitrogen and air roasting on the catalyst, wherein the nitrogen roasting is preferably carried out at the temperature of 250-350 ℃.

The catalyst in each heating zone of the reactor needs to be in sufficient, or even in excess, to achieve optimum selectivity and conversion. The catalyst may be in the form of, for example, spheres, tablets, or granules, without limitation to physical form.

(5) The product stream (6) of the third reactor passes through a multi-stage separation system, and is extracted and separated to obtain transHFO-1234 ze and cis HFO-1234ze products.

Feeding the product stream (6) from the third reactor to a third separation column, forming a stream containing HCl, HF and trans-HFO-1234 ze at the top of the column, removing and recovering the HCl and HF by means of water washing; rectifying to obtain trans-HFO-1234 ze; a material flow containing cis-HFO-1234 ze, HFC-245fa and HCFO-1233zd is formed at the tower bottom;

feeding the material flow in the bottom of the third separation tower into a fourth separation tower for extractive distillation, contacting with an extraction solvent in the extraction process, and performing rectification separation to obtain cis-HFO-1234 ze at the tower top; the tower bottom is the recovered extractant which returns to the extraction separation tower through a pipeline.

The extraction solvent comprises a mixture of alkane and chlorinated hydrocarbon, and the volume ratio of the alkane to the chlorinated hydrocarbon is 1:1-2: 1. Preferably, the alkane is selected from n-hexane and/or cyclohexane, and the chlorinated hydrocarbon is selected from carbon tetrachloride and/or trichloroethylene; further preferably, the mixture of alkanes and chlorinated hydrocarbons is a mixture of n-hexane and carbon tetrachloride.

The separation pressure of the third separation tower is preferably 0.2-0.8 MPa, and the temperature of a tower kettle is preferably 50-90 ℃; more preferably, the separation pressure of the third separation tower is consistent with the reaction pressure of the second reactor, the separation pressure is 0.3-0.5 MPa, and the temperature of a tower kettle is 50-70 ℃. The tower top of the third separation tower is preferably cooled by a refrigerant, and the temperature of the refrigerant is preferably-50 to-30 ℃.

The separation pressure of the fourth separation tower is preferably 0.1-1.2 MPa, and the temperature of the tower kettle is preferably 30-50 ℃. The tower top of the fourth separation tower (6) is cooled by a refrigerant, and the temperature of the refrigerant is preferably 10-20 ℃.

The separation pressure of the extraction separation tower is preferably 0.3-0.5 MPa, and the temperature of the tower kettle is preferably 40-60 ℃. And cooling the tower top of the extraction separation tower by adopting cooling water, wherein the temperature of the cooling water is 0-10 ℃.

The reactor, separation column and their associated feed lines, discharge lines and associated units used in the present invention should be constructed of corrosion resistant materials, typical corrosion resistant materials including nickel containing alloys, stainless steel and copper plated steel, etc.

Compared with the prior art, the process for preparing trans-HFO-1234 ze and cis-HFO-1234 ze has the following advantages:

(1) with vinyl Chloride (CH)₂CHCl) and CCl₄trans-HFO-1234 ze and cis-HFO-1234 ze products are prepared by telomerization, further fluorination and isomerization as raw materials, the raw materials are easy to obtain, the price is economic, the process is simple and easy to operate, and the method is favorable for industrial implementation;

(2) the method comprises the steps of selecting and preparing a chlorinated metal salt/molecular sieve catalyst, forming a catalytic system together with N, N-dimethylethylamine, complexing with metal amine to improve the activity of the catalyst, effectively avoiding the problems of blockage of a reaction instrument pipeline, difficulty in recovering the catalyst and the like caused by the generation of viscous organic amine salt in the reaction process of a conventional cocatalyst triethanolamine, and obviously improving the selectivity and yield of pentachloropropane;

(3) reaction temperature and pressure of the second reactor and the third reactor are reasonably selected and controlled, fluorination in the presence of a fluorination catalyst and isomerization in the presence of an isomerization catalyst are respectively carried out, trans-HFO-1234 ze and cis-HFO-1234 ze products are obtained, the process is simple, the operation is easy, and the product yield is improved.

(4) Adopts a separation mode of combining a separation tower, a standing tower and an extraction tower, finely separates, and simultaneously obtains trans-HFO-1234 ze and cis-HFO-1234 ze products.

(5) After the material flow at the bottom of the third separation tower is layered in the standing tank, the material flow with HF at the upper layer is circulated to the second reactor; the lower layer material flow is sent into a fourth separation tower, a mixed material flow containing HFC-245fa, HCFC-244fa and HCFO-1233zd is formed at the tower bottom and is circulated to a second reactor for circular reaction, the conversion rate of raw materials is effectively improved, and byproducts are reduced.

Drawings

FIG. 1 is a schematic process flow diagram of a production system of the present invention, wherein: a is a first reactor, B is a first rectifying tower, C is a second rectifying tower, D is a second reactor, E is a third reactor, F is a multistage separation system, 7 is a catalyst, and 8 is a product.

FIG. 2 is an X-ray diffraction pattern of an alumina support prior to reaction of an isomerization catalyst;

figure 3 is an X-ray diffraction pattern of an alumina support of an isomerization catalyst after reaction.

Detailed Description

The present invention is further illustrated by the following examples, which are not intended to limit the invention to these embodiments. It will be appreciated by those skilled in the art that the present invention encompasses all alternatives, modifications and equivalents as may be included within the scope of the claims.

Example 1:

containing theta-Al₂O₃And alpha-Al₂O₃Mixed crystal phase alumina

Adding aluminum isopropoxide into ethylene glycol to prepare a solution with the aluminum content of 1.0mol/L, then treating at 150 ℃ for 24 hours, centrifugally separating, washing a sample obtained by centrifugal separation with absolute ethyl alcohol, drying in air at 50 ℃ for 12 hours to obtain powder, and roasting the powder in air at 1200 ℃ for 3 hours to obtain the product containing theta-Al₂O₃And alpha-Al₂O₃A catalyst carrier in the crystal phase, the catalyst carrier having a specific surface area of 15.3m²(ii)/g, the average pore diameter is 23.3nm, the pore diameter of 92% or more is 15 to 35nm, and the X-ray diffraction pattern is shown in FIG. 2.

Trans-HFO-1234 ze was introduced and 5mL of the catalyst support prepared in this example was loaded at a reaction temperature of 350 ℃ and a space velocity of 300 hours^-1The pressure is 0.1MPa, the crystal form is unchanged after the reaction (figure 3) and the surface of the catalyst has no carbon deposition after the reaction is carried out for 10 hours, which shows that the catalyst has better stability and carbon deposition resistance.

Example 2

1% Pd-1% Na/10% SrO-contains theta-Al₂O₃And alpha-Al₂O₃Mixed crystal phase alumina

Ball-milling and mixing SrO and the catalyst carrier prepared in the embodiment 1 according to a required proportion, stirring and mixing uniformly, then tabletting or extruding for molding to obtain a doped modified carrier, and mixing the doped modified carrier and PdCl with the metal mass percent of 1%₂Soaking the soaking solution in the same volume, drying at 120 deg.C, calcining at 400 deg.C in nitrogen atmosphere for 4 hr, and reducing at 200 deg.C in hydrogen atmosphere for 2 hr to obtain Pd/SrO-containing theta-Al₂O₃And alpha-Al₂O₃Alumina in mixed crystal phases. The obtained Pd/SrO-contains theta-Al₂O₃And alpha-Al₂O₃Alumina of mixed crystal phase is dipped in NaF dipping solution with the metal mass percent of 1% in the same volume, dried at 120 ℃ and baked at 500 ℃ in a tubular furnace in nitrogen atmosphereAnd (4) burning for 4 hours to obtain the catalyst.

Example 3

In the first reactor, CCl is added₄Is prepared from CH₂CHCl into CCl₄Adding metal chloride/molecular sieve catalyst, adding N, N-dimethylethylamine and acetonitrile solvent, introducing argon, controlling the temperature at 150 deg.C and reaction pressure at 0.8MPa, and reacting to obtain CH₂CHCl and CCl₄The molar ratio is 1: 5.

The mole ratio of the chloroethylene to the chlorinated metal salt in the catalyst chlorinated metal salt/molecular sieve is 1:0.2, and the mole ratio of the chlorinated metal salt to the N, N-dimethylethylamine is 1: 3. The preparation method of the chlorinated metal salt/molecular sieve catalyst comprises the following steps: the catalyst is synthesized by taking chlorinated metal salt as an active component, selecting copper as an active component and selecting 13X molecular sieve as a carrier by an impregnation method. Firstly adding deionized water into metal chloride, stirring and dissolving to obtain a metal salt solution, then adding a molecular sieve carrier, soaking at room temperature for 11h, filtering, then placing in a drying oven, drying at 115 ℃ for 9h, and then roasting at 500 ℃ for 5 h.

The material reacted in the first reactor enters a first separation tower, the temperature of the tower bottom is 120 ℃, and the pressure is 0.09 MPa. The material at the top of the tower is CCl which is not completely reacted₄And returning to the first reactor. And (4) feeding the kettle bottom mixture into a separator, separating out the catalyst, collecting, performing additional treatment, and recycling. The stream rich in HCC-240fa enters a second separation tower, the temperature of the tower bottom is 75 ℃, the pressure is 0.1MPa, and the

target product

1,1,1,3, 3-pentachloropropane (HCC-240fa) is obtained from the top of the second separation tower. HCC-240fa is fed into the second reactor, and anhydrous HF is introduced to carry out the fluorination reaction under the action of the fluorination catalyst. The reaction temperature is 220 ℃, the reaction pressure is 0.5MPa, the molar ratio of HF to HCC-240fa is 12:1, and the space velocity is 800h^-1. The fluorination catalyst is an iron-containing chromium oxyfluoride catalyst; the mass percent of the chromium in the active metal is 85 percent; further contains other active metals, Al, Pd and La. The fluorination catalyst is pretreated by HF before use, specifically, the fluorination catalyst is placed in a catalyst reactor, and HF and N are introduced₂The molar ratio is 6:1 ofThe mixed gas is treated with fluorination at 280 ℃ for 200 minutes. The reaction product of the second reactor enters a third reactor and is subjected to isomerization reaction under the action of the isomerization catalyst in the embodiment 1; the reaction temperature of the third reactor is 300 ℃, the reaction pressure is 0.5MPa, and the airspeed of the raw materials is 1000h^-1The isomerization reaction is carried out in the gas phase.

The product stream (6) of the third reactor is sent into a third separation tower, a stream containing HCl, HF and trans-HFO-1234 ze is formed at the top of the tower, and the HCl and the HF are removed and recovered by adopting a water washing mode; rectifying to obtain trans-HFO-1234 ze; a material flow containing cis-HFO-1234 ze, HFC-245fa and HCFO-1233zd is formed at the tower bottom; feeding the material flow in the bottom of the third separation tower into a fourth separation tower for extractive distillation, contacting with an extraction solvent in the extraction process, and performing rectification separation to obtain cis-HFO-1234 ze at the tower top; the tower bottom is the recovered extractant which returns to the extraction separation tower through a pipeline. The extraction solvent comprises a mixture of n-hexane and carbon tetrachloride, and the volume ratio of alkane to chlorinated hydrocarbon is 2: 1.

Example 4

The mole ratio of the chloroethylene to the chlorinated metal salt in the catalyst chlorinated metal salt/molecular sieve is 1:0.2, and the mole ratio of the chlorinated metal salt to the N, N-dimethylethylamine is 1: 3. The preparation method of the chlorinated metal salt/molecular sieve catalyst comprises the following steps: the catalyst is synthesized by taking chlorinated metal salt as an active component, selecting palladium as a metal and taking a molecular sieve as a 5A molecular sieve by an impregnation method. Firstly adding deionized water into metal chloride, stirring and dissolving to obtain a metal salt solution, then adding a molecular sieve carrier, soaking at room temperature for 11h, filtering, then placing in a drying oven, drying at 115 ℃ for 9h, and then roasting at 500 ℃ for 5 h.

The remaining procedure was the same as in example 3.

Example 5

In the first reactor, CCl is added₄Introducing vinyl chloride into CCl₄Then adding metal chloride/molecular sieve catalyst, adding N, N-dimethylethylamine and acetonitrile solvent, introducing argon, controlling the temperature at 150 deg.C and the reaction pressure at 0.8MPa, and reacting. CH (CH)₂CHCl and CCl₄The molar ratio is 1: 5.

The material reacted in the first reactor enters a first separation tower, the temperature of the tower bottom is 120 ℃, and the pressure is 0.09 MPa. The material at the top of the tower is CCl which is not completely reacted₄And returning to the first reactor. And (4) feeding the kettle bottom mixture into a separator, separating out the catalyst, collecting, performing additional treatment, and recycling. And the stream rich in HCC-240fa enters a second separation tower, the temperature of the tower bottom is 75 ℃, the pressure is 0.1MPa, and a target product HCC-240fa is obtained from the bottom of the second separation tower. HCC-240fa is fed into the second reactor, in which anhydrous HF is introduced, and the fluorination is carried out in the presence of a fluorination catalyst. The reaction temperature is 220 ℃, the reaction pressure is 0.5MPa, the molar ratio of HF to HCC-240fa is 12:1, and the space velocity is 800h^-1. Fluorination catalystThe agent is an iron-containing chromium oxyfluoride catalyst; the mass percent of the chromium in the active metal is 85 percent; further contains other active metals Al, Pd and La. The fluorination catalyst was pretreated with HF before use. The specific pretreatment mode is that the fluorination catalyst is placed in a catalyst reactor, and HF and N are introduced₂The molar ratio is 6:1, and fluorination treatment at 280 ℃ for 200 minutes. The reaction product of the second reactor is sent to a third reactor, and isomerization reaction is carried out under the action of the isomerization catalyst in the embodiment 2; the third reactor, the reaction temperature is 350 ℃, the reaction pressure is 0.6MPa, and the space velocity of the raw materials is 900h^-1The isomerization reaction is carried out in the gas phase.

The separation pressure of the third separation tower is 0.5MPa, the temperature of the tower bottom is preferably 70 ℃, the tower top is cooled by a refrigerant, and the temperature of the refrigerant is-30 ℃. The separation pressure of the fourth separation tower is 0.9MPa, and the temperature of the tower bottom is 40 ℃. The tower top of the fourth separation tower is cooled by a refrigerant, and the temperature of the refrigerant is 10 ℃. The separation pressure of the extraction separation tower is 0.3MPa, and the temperature of the tower bottom is 40 ℃. The top of the extraction separation tower is cooled by cooling water, and the temperature of the cooling water is 5 ℃.

Example 6

In the first reactor, CCl is added₄Introducing vinyl chloride into CCl₄Then adding a metal chloride salt/molecular sieve catalyst, adding N, N-dimethylethylamine and an acetonitrile solvent, introducing argon, controlling the temperature at 150 ℃ and the reaction pressure at 0.8MPa, and reacting. CH (CH)₂CHCl and CCl₄The molar ratio is 1: 5.

The remaining procedure was the same as in example 5.

Comparative example 1

In the first reactor, CCl is added₄Introducing vinyl chloride into CCl₄Then adding a copper chloride catalyst, adding triethanolamine and an acetonitrile solvent, introducing argon, controlling the temperature at 150 ℃ and the reaction pressure at 0.8MPa, and reacting. CH (CH)₂CHCl and CCl₄The molar ratio is 1: 5.

The molar ratio of the vinyl chloride to the copper chloride is 1:0.2, and the molar ratio of the copper chloride to the triethanolamine is 1: 3.

The remaining procedure was the same as in example 3.

Comparative example 2

The material reacted in the first reactor enters a first separation tower, the temperature of the tower bottom is 120 ℃, and the pressure is 0.09 MPa. The material at the top of the tower is CCl which is not completely reacted₄And returning to the first reactor. And (4) feeding the kettle bottom mixture into a separator, separating out the catalyst, collecting, performing additional treatment, and recycling. And the stream rich in HCC-240fa enters a second separation tower, the temperature of the tower bottom is 75 ℃, the pressure is 0.1MPa, and a target product HCC-240fa is obtained from the bottom of the second separation tower. HCC-240fa was fed to the second reactor for fluorination: anhydrous HF is introduced, and the fluorination reaction is carried out under the action of a fluorination catalyst. The reaction temperature is 220 ℃, the reaction pressure is 0.5MPa, the molar ratio of HF to HCC-240fa is 12:1, and the space velocity is 800h^-1. The fluorination catalyst is an iron-containing chromium oxyfluoride catalyst; the fluorination catalyst was pretreated with HF before use. The specific pretreatment mode is that the fluorination catalyst is placed in a catalyst reactor, and HF and N are introduced₂The molar ratio is 6:1, and fluorination treatment at 280 ℃ for 200 minutes.

The remaining procedure was the same as in example 3.

TABLE 1

Detecting items

Example 3

Example 4

Example 5

Example 6

Comparative example 1

Comparative example 2

HFO-1234ze selectivity

91.3％

90.8％

91.6％

91.5％

42.8％

43.4％

HFO-1234ze yield

93.3％

94.1％

94.7％

93.9％

51.7％

49.6％

Conversion of feedstock

100％

79.3％

73.8％

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.

Claims

1. A process for the co-production of transhfo-1234 ze and cishfo-1234 ze, characterized by the steps of:

step (1) with vinyl Chloride (CH)₂CHCl) and carbon tetrachloride (CCl)₄) Synthesizing a feed stream (1) by a telomerization reaction in a first reactor to obtain 1,1,1,3, 3-pentachloropropane (HCC-240fa), wherein a catalyst system is formed by a chlorinated metal salt/molecular sieve catalyst and N, N-dimethylethylamine in the telomerization reaction;

step (2), separating HCC-240fa by a rectifying tower;

step (3), feeding a target product HCC-240fa (4) of the rectifying tower into a second reactor, introducing anhydrous HF into the second reactor, and performing a fluorination reaction under the action of a fluorination catalyst;

step (4), the reaction product (5) in the second reactor enters a third reactor, isomerization reaction is carried out under the action of isomerization catalyst, trans-HFO-1234 ze is converted into cis-HFO-1234 ze, and the catalyst carrier of the isomerization catalyst is alumina and contains theta-Al₂O₃And alpha-Al₂O₃A mixed crystalline phase;

and (5) the third reactor product stream (6) passes through a multi-stage separation tower, and trans-HFO-1234 ze and cis-HFO-1234 ze products are obtained through extraction separation.

2. The preparation process of claim 1, wherein the molar ratio of the metal chloride salt to the vinyl chloride salt is 1: 0.1-0.8, and the molar ratio of the metal chloride salt to the molecular sieve catalyst to the N, N-dimethylethylamine is 1: 1.5-5, based on the metal chloride salt in the catalyst metal chloride salt/molecular sieve in the step (1).

3. The process of claim 1 or 2, wherein the metal chloride salt/molecular sieve catalyst in step (1) comprises a metal chloride salt as an active component, the metal is selected from at least one of magnesium, iron, copper, calcium and palladium, and the molecular sieve support is selected from at least one of 3A, 4A, 5A and 13X molecular sieves.

4. The process according to claim 1 or 2, wherein the isomerization catalyst in the step (4) has a specific surface area of the carrier of 10 to 20m²(ii)/g, the average pore diameter is 20 to 30 nm.

5. The process according to claim 4, wherein the isomerization catalyst in the step (4) has a concentrated pore size distribution, and 80% or more of the pores have a pore size of 15 to 35 nm.

6. The preparation process of claim 1 or 2, wherein the mass percentage of the carrier, the active component, the doping component and the auxiliary agent of the catalyst in the isomerization catalyst in the step (4) is 1: 0.001-0.2: 0-0.2.

7. The preparation process of claim 6, wherein the isomerization catalyst in the step (4) comprises the carrier, the active component, the doping component and the auxiliary agent in a mass ratio of 1: 0.01-0.05: 0.001-0.1.

8. The process according to claim 7, wherein the doping component of the isomerization catalyst in the step (4) is one or more selected from the group consisting of magnesium, strontium, calcium and barium, and the auxiliary agent of the isomerization catalyst is cesium.

9. The process according to claim 1 or 2, wherein the chlorinated metal salt/molecular sieve catalyst in step (1) is prepared by the following method: firstly adding deionized water into metal chloride, stirring and dissolving to obtain a metal salt solution, then adding a molecular sieve carrier, soaking at room temperature for 8-12 h, filtering, then placing in a drying oven, drying at 110-120 ℃ for 8-13 h, and roasting at 500 ℃ for 5 h.

10. The preparation process of claim 1 or 2, wherein the telomerization reaction in step (1) adopts acetonitrile as a solvent, the molar ratio of vinyl chloride to carbon tetrachloride is 1: 1.5-8, in the first reactor, raw material carbon tetrachloride is added, vinyl chloride is introduced into carbon tetrachloride, after metal chloride salt/molecular sieve catalyst and N, N-dimethylethylamine and acetonitrile solvent are added, inert gas nitrogen, helium or argon is introduced, the temperature is controlled at 110-170 ℃, and the reaction pressure is controlled at 0.4-1.1 MPa.