CN112624897A

CN112624897A - Process for the simultaneous production of trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene

Info

Publication number: CN112624897A
Application number: CN201910906748.0A
Authority: CN
Inventors: 岳晓日; 蒋宁飞
Original assignee: Jiangxi Tianyu Chemical Co ltd
Current assignee: Jiangxi Tianyu Chemical Co ltd
Priority date: 2019-09-24
Filing date: 2019-09-24
Publication date: 2021-04-09

Abstract

The invention provides a method for simultaneously producing trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene, which takes at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene and 1,1,1, 3-tetrachloropropene and hydrogen fluoride as raw materials and is prepared by gas phase or liquid phase reaction. The purity of the raw material or the raw material mixture in the method does not need to be very high and can be lower than 99.8 percent; the mass content of 1,1,1,2, 3-pentachloropropane (HCC-240fa isomer) as an impurity can be higher than 0.2 percent, and the anhydrous hydrogen fluoride is used as a fluorinating agent, so that the trans-1-chloro-3, 3, 3-trifluoropropene and the trans-1, 3,3, 3-tetrafluoropropene can be simultaneously produced.

Description

Process for the simultaneous production of trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene

Technical Field

The invention belongs to the field of compound preparation, and relates to a method for simultaneously producing trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene.

Background

The use of chlorofluorocarbons or hydrochlorofluorocarbons or hydrofluorocarbons as refrigerants, foam blowing agents, solvents and aerosol propellants has been banned because of their emission which destroys the ozone layer. Recently, there has been an increasing concern that the use of chlorofluorocarbons or hydrochlorofluorocarbons or hydrofluorocarbons may cause global warming because these compounds have a high Global Warming Potential (GWP). Trans-1-chloro-3, 3, 3-trifluoropropene (HCFO-1233zd (E)) and trans-1, 3,3, 3-tetrafluoropropene (HFO-1234ze (E)) are two compounds with zero or near zero ODP and low GWP (less than 1). HCFO-1233zd (E) and HFO-1234ze (E) are considered environmentally friendly compounds for replacement of chlorofluorocarbons or hydrochlorofluorocarbons or hydrofluorocarbons with high ODP and GWP.

Methods for preparing these two materials are mentioned in the prior art, for example USP 6, 844, 475 describes the preparation of HCFO-1233zd (e) from 1,1,1,3, 3-pentachloropropane in the liquid phase in the presence of a lewis acid catalyst. Methods for preparing HFO-1234ze (E) from HFC-245fa are described in USP 7,230,146 and 7,485,760. Processes for the simultaneous production of HCFO-1233zd (E), HFO-1234ze (E), and HFC-245fa are disclosed in USP 9, 334, 207B2 and 9, 938, 212B 2; in both of the above-mentioned patent applications, HFC-245fa is used as an intermediate in the preparation of trans-1234 ze; whereas HFC-245fa is produced by reacting HCFO-1233zd with HF in the presence of a catalyst in the liquid phase. CN 102164881 discloses the use of a single 1,1,1,3, 3-pentachloropropane (HCC-240fa) feedstock to produce HCFO-1233zd (E) and then HCFO-1233zd (E) to produce HFO-1234ze (E), which requires the use of a single feedstock and only produces HCFO-1233zd (E) first and then HCFO-1233zd (E) to produce HFO-1234ze (E); CN 103402953 discloses a method for producing HCFO-1233zd (e) with high purity, but requires that the mass content of impurity 1,1,1,2, 3-pentachloropropane in the raw material is less than 0.2%.

Therefore, it is desired in the art to develop a process which has low requirements for raw materials and is capable of simultaneously producing trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene.

Disclosure of Invention

In view of the disadvantages of the prior art, the present invention aims to provide a process for simultaneously producing trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene. The purity of the raw material or the raw material mixture in the method does not need to be very high and can be lower than 99.8 percent; the mass content of 1,1,1,2, 3-pentachloropropane (HCC-240fa isomer) as an impurity can be higher than 0.2 percent, and the anhydrous hydrogen fluoride is used as a fluorinating agent, so that the trans-1-chloro-3, 3, 3-trifluoropropene and the trans-1, 3,3, 3-tetrafluoropropene can be simultaneously produced.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a process for the simultaneous production of trans-1-chloro-3, 3, 3-trifluoropropene (HCFO-1233zd (e)) and trans-1, 3,3, 3-tetrafluoropropene (HFO-1234ze (e)), which is prepared by a gas phase or liquid phase reaction starting from at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene, 1,1,1, 3-tetrachloropropene, and hydrogen fluoride.

In the invention, the raw materials are not required to be single raw materials, the purity requirement of the raw materials is not high, the mixed raw materials can be used for simultaneously obtaining trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene by using gas phase reaction without purifying the raw materials, the reaction efficiency is high, and the yield is high.

In the present invention, the purity of the raw material is 99.5% to 99.8%, such as 99.5%, 99.53%, 99.55%, 99.58%, 99.6%, 99.63%, 99.65%, 99.67%, 99.7%, 99.72%, 99.75%, 99.78%, 99.8%, etc. In the present invention, the purity of the raw material may be less than 99.8%, and the content of impurities in the raw material may be higher than 0.2%.

In the invention, the purity of the raw material refers to the total mass percentage of the active ingredients of the raw material (namely the total mass percentage of at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene and 1,1,1, 3-tetrachloropropene); in the present invention, the impurities are mainly 1,1,1,2, 3-pentachloropropane (HCC-240fa isomer).

Preferably, the process is carried out using two gas phase reactors or one liquid phase, one gas phase reactor, the feed is fed into the first reactor and the gas phase or liquid phase reaction is carried out with or without a catalyst to produce trans-1-chloro-3, 3, 3-trifluoropropene; feeding the heavy by-product produced in the first reactor into a second reactor, and carrying out gas-phase reaction with hydrogen fluoride in the presence of a catalyst to obtain trans-1, 3,3, 3-tetrafluoropropene.

In the present invention, the first reactor may be in liquid or vapor phase, with or without catalyst, to produce HCFO-1233zd (E) in the reaction, and the second reactor produces heavy by-products from the reaction of HCFO-1233zd (E) and HCFO-1233zd (E) in the presence of catalyst, such as HCFC-242fa, HCFC-243fb, HCFC-243fa, HCFC-244fa, HCFO-1233zd (Z) and other heavy intermediates, to produce HFO-1234ze (E) in vapor phase.

In the present invention, the main chemical reaction in the first reactor is as follows:

in the present invention, the side reactions in the first reactor are as follows:

in the present invention, the main chemical reaction in the second reactor is as follows:

the reaction to produce HCFO-1233zd in the first reactor is either in the gas phase or in the liquid phase, either catalytic or non-catalytic. When the catalyst is not used, the surface agents such as active carbon or corrosion-resistant metal mesh and the like can be used as reaction carriers; when a catalyst is used, the catalyst may comprise any one or a combination of at least two of the following: activated carbon, ferric trichloride, chromium (III) oxide, fluorinated chromium (III) oxide supported on fluorinated alumina, fluorinated chromium (III) oxide supported on activated carbon, fluorinated chromium (III) oxide supported on alumina or fluorinated chromium (III) oxide supported on aluminum fluoride the corrosion-resistant metal mesh mainly refers to an acid corrosion-resistant metal mesh.

In the invention, after the reaction in the first reactor is finished, the residual hydrogen fluoride is recovered, the hydrogen chloride generated by the reaction is removed, and then the first organic phase product is obtained by separation through a first phase separator.

Preferably, the residual hydrogen fluoride is recovered by utilizing a hydrogen fluoride recycling tower.

Preferably, the hydrogen chloride produced by the reaction is removed using a hydrogen chloride separation column.

In the invention, after the gas phase reaction in the second reactor is completed, the residual hydrogen fluoride is recovered, the hydrogen chloride generated in the reaction is removed, the reactants with the hydrogen fluoride and the hydrogen chloride removed enter a second phase separator, the first phase separator is separated to obtain a first organic phase product, the first organic phase product is fed to the second phase separator and is separated to obtain a second organic phase product (the second organic phase after passing through the second phase separator comprises the majority of the produced 1234ze (E) and 1233zd (E)).

Preferably, the second organic phase product is rectified to obtain trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene.

Preferably, the molar ratio of the total amount of at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene or 1,1,1, 3-tetrachloropropene to hydrogen fluoride in the first reactor is 1:10 to 1: 30; e.g., 1:10, 1:11, 1:12, 1:13, 1:15, 1:17, 1:19, 1:20, 1:22, 1:24, 1:25, 1:27, 1:30, etc., preferably 1:15 to 1: 25; more preferably 1:20 to 1: 25.

Preferably, the temperature of the reaction in the first reactor is 120-.

Preferably, the pressure of the reaction in the first reactor is 0.5-3.5 MPa; for example, 0.5MPa, 0.8MPa, 1MPa, 1.2MPa, 1.5MPa, 1.8MPa, 2MPa, 2.5MPa, 2.8MPa, 3MPa, 3.3MPa or 3.5MPa, and more preferably 0.6 to 3.4 MPa.

Preferably, the reaction time in the first reactor is 30 seconds to 3 hours; for example, 30 seconds, 40 seconds, 50 seconds, 60 seconds, 5 minutes, 10 minutes, 30 minutes, 50 minutes, 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours, etc., and more preferably 60 seconds to 2 hours.

Preferably, the temperature of the gas phase reaction in the second reactor is 150-.

Preferably, the pressure of the gas phase reaction in the second reactor is in the range of 0.5 to 1MPa, such as 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa or 1MPa, more preferably 0.6 to 0.8 MPa.

Preferably, the gas phase reaction in the second reactor is for a time in the range of 30 to 120 seconds, such as 30 seconds, 40 seconds, 50 seconds, 60 seconds, 70 seconds, 80 seconds, 90 seconds, 100 seconds, 110 seconds or 120 seconds, more preferably 45 to 100 seconds.

In the present invention, the catalyst in the second reactor is any one of chromium (III) oxide, fluorinated chromium (III) oxide supported on fluorinated alumina, fluorinated chromium (III) oxide supported on activated carbon, fluorinated chromium (III) oxide supported on alumina, or fluorinated chromium (III) oxide supported on aluminum fluoride, or a combination of at least two thereof.

In the present invention, the separation efficiency of HF and organic products can be improved by using two-stage phase separators in series to separate the organic products from HF. The feed from the first reactor, from the bottom layer of the first phase separator, comprising HCFO-1233zd (e), HCFC-242fa, HCFC-243fb, HCFO-1233zd (z) and other organic by-products, is fed to a second phase separator and used as an extractant to extract HFO-1234ze (e) crude product from the second reactor, comprising HF, HFO-1234ze (e) intermediates and by-products from the second reactor, increasing the separation efficiency of the organic products from HF. Thus increasing the yield of HF and the target products (HCFO-1233zd (E) and HFO-1234ze (E)).

In the present invention, the impurity 2-chloro-3, 3, 3-trifluoropropene in the final product (i.e., the product obtained after rectification) trans-1-chloro-3, 3, 3-trifluoropropene is removed by molecular sieve or activated carbon or a combination of both.

Preferably, the molecular sieve is a 4A molecular sieve and/or a 5A molecular sieve.

Preferably, the activated carbon is coconut shell activated carbon.

The present invention uses molecular sieves or activated carbon or a combination of both to remove unsaturated impurities. Especially 4A, 5A molecular sieve and coconut shell activated carbon with high specific surface are more effective.

Compared with the prior art, the invention has the following beneficial effects:

the method takes at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene and 1,1,1, 3-tetrachloropropene and hydrogen fluoride as raw materials to realize the simultaneous production of trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene, the purity of the raw materials does not need to be very high and can be lower than 99.8%, and the mass content of impurities can be higher than 0.2%.

In the present invention, the reaction is accomplished using two reactors, the first reactor, which may be gas or liquid phase, with or without catalyst, to produce HCFO-1233zd (E) in the reaction, and the second reactor, which produces HFO-1234ze (E) in the gas phase from the heavy by-products of the reaction from HCFO-1233zd (E) and HCFO-1233zd (E) in the presence of catalyst.

The method can simultaneously produce trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene, and has high product purity and high yield.

Drawings

FIG. 1 is a diagram of an apparatus for simultaneously producing trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene according to the present invention;

FIG. 2 is a schematic flow diagram of a stream using two phase separators in series in the present invention;

FIG. 3 is a schematic flow diagram of a stream using a single phase separator.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

In this example, trans-1-chloro-3, 3, 3-trifluoropropene and trans-1, 3,3, 3-tetrafluoropropene are produced from a mixture of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene, and 1,1,1, 3-tetrachloropropene, and hydrogen fluoride as raw materials by the following specific methods:

the process flow of the method in this example is shown in FIG. 1, and both reactors are gas phase reactors. The first reactor is a phi 10cm multiplied by 148cm reactor of Inconel, the main discharging component is trans-1233zd (trans-1-chloro-3, 3, 3-trifluoropropene), the first reactor is connected with an HF recycling tower, the diameter of the HF recycling tower is 10cm, and a reboiler at the bottom of the tower is 40 liters; enabling the tower top material flow of the HF recovery tower to enter an HCl separation tower with the same size and structure to remove HCl; feeding the crude product from the bottom of the HCl tower into a 20-liter first phase separator, returning an HF phase to an HF recovery tower after layering, and feeding an organic phase into a 20-liter second phase separator; one part of the feed of the second phase separator is from the first phase separator, and the other part of the feed is from the discharge of the second reactor after HCl removal; the second reactor is a phi 5cm x 148cm reactor of Inconel, the discharged main components are trans-1233zd and trans-1234ze (trans-1, 3,3, 3-tetrafluoropropene), and the second reactor is connected with an HCl separation tower with the diameter of 10 cm; the bottom of the HCl separation tower is a 40-liter reboiler, the byproduct HCl is removed from the top of the HCl tower, and the bottom crude product of the HCl separation tower enters a second phase separator; returning the HF layer of the second phase separator to an HF recovery tower, and allowing the organic phase to enter a crude product separation tower; the bottom stream of the crude product tower enters a second reactor, and the top stream mainly comprises target products of trans-1233zd and trans-1234ze and enters subsequent conventional purification and rectification units, including a water/alkali washing tower, a trans-1234ze purification unit and a trans-1233zd purification unit.

In the first reaction stage, activated carbon is filled into the first reactor as a reaction carrier to increase the contact area between the organic raw material and the fluorinating agent (anhydrous HF). To the first reactor was fed a mixture of 1,1,1,3, 3-pentachloropropane (HCC-240fa content of about 50% by mass), 1,1,3, 3-tetrachloropropene (HCC-1230za content of about 40% by mass) and 1,1,1, 3-tetrachloropropene (HCC-1230zb content of about 10% by mass) at a feed rate of 1kg/hr, and simultaneously added fresh and recycled HF (feed rate of 2.55kg/hr after reaching steady state) such that the molar ratio of feed to HF was about 1: 25. the raw material feed contains about 0.3% by mass of 1,1,1,2, 3-pentachloropropane impurities. The reactor was heated to 250 ℃ and maintained at a pressure of 0.78MPa for a reaction time of about 56 seconds. The outlet of the first reactor (stream 1) enters an HF recycling tower, and the stream 1 contains 63.2% of HF and 17.8% of HCl by mass, and the rest is organic products. Wherein the mass composition of the organic product is as follows: 80.5% 1233zd (E), 8.0% 1233zd (Z), 1.7% 1234ze (E), 1.5% 245fa, 1.5% 244fa, 5.6% 242fa, and 1.2% other components. The flow rate of the recycle stream at the bottom of the HF recovery column was about 2.333g/hr in a steady state, and the HF content by mass was 99.7%. The top stream of the HF recovery column (stream 2) enters the HCl separation column. Removing byproduct HCl from the top of the HCl tower; the HCl column bottoms stream (stream 4) was passed to a first phase separator, which was operated at-20 ℃. Returning the HF layer (stream 5) to the HF recovery column, and feeding the organic layer (stream 6) to a second phase separator at a flow rate of about 0.72kg/hr under steady state conditions; the second phase separator was operated at-20 c with an additional portion fed from the second HCl column (stream 8) at a steady state flow rate of about 0.35kg/hr, the HF layer in the second phase separator (stream 9) was returned to the HF recovery column, the organic layer (stream 10) was fed to the crude product column at a steady state flow rate of 0.93kg/hr, the mass composition of this stream being: 1.5% of HF, 98.5% of organic matter; the organic matter comprises the following components in percentage by mass: 65.3% 1233zd (E), 7.3% 1233zd (Z), 17.2% 1234ze (E), 2.5% 245fa, 1.1% 244fa, 4.6% 242fa, and 2% others.

In the second reaction stage, the second reactor (. PHI.5 cm. times.148 cm) was filled with a fluorinated chromium (III) oxide catalyst supported on activated carbon. The reactants in the second reactor were 1233zd (E) from the first reactor and by-products containing 7.9% by mass 245fa, 2.9% 1234ze (Z), 47.2% 1233zd (E), 3.7% 244fa, 23.2% 1233zd (Z), 4.1% 243fb, 10.6% 242fa, and 0.4% others, this feed was fed at 0.29kg/hr, anhydrous HF was fed at 0.12kg/hr, the second reactor product was the target product 1234ze (E). The second reactor was heated to 350 ℃ and maintained at a pressure of 0.78MPa for a reaction time of about 4 minutes. The outlet of the second reactor (stream 7) enters an HCl separation column, and the mass composition of the stream 7 is as follows: 24% HF, 15% HCl, 36.7% 1234ze (E) and 24.3% other organic products which can be recycled. Removing byproduct HCl from the top of the HCl separation tower; the HCl-depleted crude product (stream 8) is passed from the bottom of the column to a second phase separator and then to the crude column and to a subsequent rectification unit.

The final product from the 1233zd purification unit contains unsaturated impurity 2-chloro-3, 3, 3-trifluoropropene, and the unsaturated impurity 2-chloro-3, 3, 3-trifluoropropene is removed from the purified trans-1-chloro-3, 3, 3-trifluoropropene (HCFO-1233zd (E)) product, the specific method is as follows: the stream was passed through a stainless steel tube 2 inches in diameter and 3 feet long containing 5A molecular sieve adsorbent. Approximately 5kg of a product fraction of 1-chloro-3, 3, 3-trichloropropene (HCFO-1233zd (E)) having a 2-chloro-3, 3, 3-trifluoropropene content of 2000ppm was continuously circulated in stainless steel tubes by means of a mechanical pump. Over a 4 hour cycle, the concentration of 2-chloro-3, 3, 3-trifluoropropene dropped to 34 ppm.

In summary, this example gave 27.2% yield of 1234ze (E) and 69.0% yield of 1233zd (E) based on the organic feed (1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene, and 1,1,1, 3-tetrachloropropene); 1234ze (E) yield was 31.7% based on HF feed, 1233zd (E) yield was 60.1%.

Example 2

In this example, the same apparatus as in example 1 was used.

In the first reaction stage, activated carbon serving as a reaction carrier, a corrosion-resistant metal mesh is filled in the first reactor, and the raw material is a mixture of 1,1,3, 3-tetrachloropropene (HCC-1230za) and 1,1,1, 3-tetrachloropropene (HCC-1230 zb). The mass content of 1,1,1,2, 3-pentachloropropane impurity in the mixture is 0.5%. This mixture was fed to the first reactor at a rate of 1kg/hr (4: 1 HCC-1230za/HCC1230zb mass ratio) and fresh and recycled HF were added simultaneously (2.78 kg/hr feed rate after steady state) to achieve a molar ratio of organics to HF of 1: 25. the reactor was heated to 250 ℃ and maintained at a pressure of 0.78MPa for a reaction time of about 60 seconds. The outlet of the first reactor (stream 1) enters an HF recycling tower, the stream 1 contains HF with the mass content of 65% and HCl with 16%, and the rest is organic products. Wherein the mass composition of the organic product is as follows: 84.7 weight percent 1233zd (E), 8.5 weight percent 1233zd (Z), 1.0 weight percent 1234ze (E), 1.3 weight percent 245fa, 1.1 weight percent 244fa, 2.5 weight percent 242fa, and 0.9 weight percent other components. The recycle stream at the bottom of the HF recovery column was about 2.5kg/hr at steady state and had an HF content of 99.7% by mass. The top stream of the HF recovery column (stream 2) enters the HCl separation column. Removing byproduct HCl from the top of the HCl tower; the HCl column bottoms stream (stream 4) was passed to a first phase separator, which was operated at-20 ℃. Returning the HF layer (stream 5) to the HF recovery column, and feeding the organic layer (stream 6) to a second phase separator at a flow rate of about 0.79kg/hr under steady state conditions; the second phase separator was operated at-20 c with an additional portion fed from the second HCl column (stream 8) at a steady state flow rate of about 0.37kg/hr, the HF layer in the second phase separator (stream 9) was returned to the HF recovery column, the organic layer (stream 10) was fed to the crude product column at a steady state flow rate of 1.01kg/hr, and the mass composition of this stream was: 1.4% of HF, 98.6% of organic matter; the organic matter comprises the following components in percentage by mass: 67.8% 1233zd (E), 7.6% 1233zd (Z), 17.2% 1234ze (E), 2.3% 245fa, 0.9% 244fa, 2.3% 242fa, and 1.9% others.

In the second reaction stage, a second reactor (. PHI.5 cm. times.148 cm) was filled with a fluorinated chromium oxide catalyst. The reactants in the second reactor were 1233zd (E) from the first reactor and by-products containing 7.3% by mass of 245fa, 2.8% of 1234ze (Z), 55.0% of 1233zd (E), 2.7% of 244fa, 24.2% of 1233zd (Z), 2.1% of 243fb, 5.3% of 242fa and 0.6% of other materials, this feed was fed at 0.31kg/hr, anhydrous HF was fed at 0.13kg/hr, the second reactor product was the target product 1234ze (E). The second reactor was heated to 350 ℃ and maintained at a pressure of 0.78MPa for a reaction time of about 4 minutes. The outlet of the second reactor (stream 7) enters an HCl separation column, and the mass composition of the stream 7 is as follows: 23.8% HF, 16.0% HCl, 37.2% 1234ze (E) and 23.0% other organic products that can be recycled. Removing byproduct HCl from the top of the HCl separation tower; the crude product freed from HCl (stream 8) is passed from the bottom of the column into a second phase separator. Then enters a crude product tower and a subsequent rectification unit.

The crude product from the 1233zd purification unit contains unsaturated impurity 2-chloro-3, 3, 3-trifluoropropene, and the unsaturated impurity 2-chloro-3, 3, 3-trifluoropropene is removed from the purified trans-1-chloro-3, 3, 3-trifluoropropene (HCFO-1233zd (E)) product, the specific method is as follows: the stream was passed through a stainless steel tube 2 inches in diameter and 3 feet long containing 5A molecular sieve adsorbent. Approximately 5kg of a product fraction of 1-chloro-3, 3, 3-trichloropropene (HCFO-1233zd (E)) having a 2-chloro-3, 3, 3-trifluoropropene content of 850ppm was continuously circulated in stainless steel tubes by means of a mechanical pump. After 4 hours of circulation, the concentration of 2-chloro-3, 3, 3-trifluoropropene was reduced to 20 ppm.

In summary, this example gives a 26.7% yield of 1234ze (E) and a 69.1% yield of 1233zd (E) based on the organic feed (1,1,3, 3-tetrachloropropene and 1,1,1, 3-tetrachloropropene); 1234ze (E) yield was 31.7% based on HF feed, 1233zd (E) yield was 61.6%.

Example 3

The process flow of the method in this example is different from that of examples 1 and 2 in that the first reactor is a liquid phase reactor, and the rest is completely the same.

The first reactor is a 20-liter liquid phase reactor made of Inconel 600, stirring paddles are arranged in the reactor, and 10 liters of anhydrous HF and 500g of FeCl are filled in the reactor before the reaction starts₃. At the start of the reaction, a mixture of 1,1,1,3, 3-pentachloropropane (HCC-240fa content of about 50% by mass), 1,1,3, 3-tetrachloropropene (HCC-1230za content of about 40% by mass) and 1,1,1, 3-tetrachloropropene (HCC-1230zb content of about 10% by mass) was fed into the first reactor at a feed rate of 1kg/hr, and fresh and recycled HF (feed rate of 0.71kg/hr after reaching steady state) were added simultaneously to give a feed to HF molar ratio of about 1: 7. the raw material feed contains about 0.3% by mass of 1,1,1,2, 3-pentachloropropane impurities. The reactor was heated to 140 ℃ and maintained at a pressure of 2.5MPa for a reaction time of about 2 hours. The outlet of the first reactor (stream 1) enters an HF recycling tower, and the stream 1 contains 23.6 mass percent of HF and 37.0 mass percent of HCl, and the rest is organic products. Wherein the mass composition of the organic product is as follows: 82% 1233zd (E), 8.0% 1233zd (Z), 1.2% 1234ze (E), 2.4% 245fa, 1.6% 244fa, 3.1% 242fa, and 1.7% other components. The flow rate of the recycle stream at the bottom of the HF recovery column was about 2.333g/hr in a steady state, and the HF content by mass was 99.7%. The top stream of the HF recovery column (stream 2) enters the HCl separation column. Removing byproduct HCl from the top of the HCl tower; the HCl column bottoms stream (stream 4) was passed to a first phase separator, which was operated at-20 ℃. Returning the HF layer (stream 5) to the HF recovery column, and feeding the organic layer (stream 6) to a second phase separator at a flow rate of about 0.73kg/hr under steady state conditions; the second phase separator is operated at-20 ℃, whichThe other part of the feed comes from the second HCl column (stream 8) at a steady state flow rate of about 0.34kg/hr, the HF layer (stream 9) in the second phase separator is returned to the HF recovery column, the organic layer (stream 10) enters the crude product column at a steady state flow rate of 0.92kg/hr, and the mass composition of the streams is: 1.4% of HF, 98.6% of organic matter; the organic matter comprises the following components in percentage by mass: 66.1% 1233zd (E), 7.3% 1233zd (Z), 17.5% 1234ze (E), 3.1% 245fa, 1.2% 244fa, 2.8% 242fa, and 2% others.

In the second reaction stage, a second reactor (. PHI.5 cm. times.148 cm) was filled with a fluorinated chromium oxide catalyst. The reactants in the second reactor were 1233zd (E) from the first reactor and by-products containing 9.7% by mass of 245fa, 2.8% of 1234ze (Z), 51.9% of 1233zd (E), 3.8% of 244fa, 22.7% of 1233zd (Z), 2.4% of 243fb, 6.2% of 242fa and 0.5% of other materials, this feed was fed at 0.29kg/hr, anhydrous HF was fed at 0.12kg/hr, the second reactor product was the target product 1234ze (E). The second reactor was heated to 350 ℃ and maintained at a pressure of 0.78MPa for about 4 minutes. The outlet of the second reactor (stream 7) enters an HCl separation column, and the mass composition of the stream 7 is as follows: 25.4% HF, 14.1% HCl, 38.5% 1234ze (E) and 22.0% other organic products that can be recycled. Removing byproduct HCl from the top of the HCl separation tower; the HCl-removed crude product is passed from the bottom of the column to a second phase separator.

The crude product from the 1233zd purification unit contains unsaturated impurity 2-chloro-3, 3, 3-trifluoropropene, and the unsaturated impurity 2-chloro-3, 3, 3-trifluoropropene is removed from the purified trans-1-chloro-3, 3, 3-trifluoropropene (HCFO-1233zd (E)) product, the specific method is as follows: the stream was passed through a stainless steel tube 2 inches in diameter and 3 feet long containing 5A molecular sieve adsorbent. Approximately 5kg of a product fraction of 1-chloro-3, 3, 3-trichloropropene (HCFO-1233zd (E)) having a 2-chloro-3, 3, 3-trifluoropropene content of 1200ppm was continuously circulated in stainless steel tubes by means of a mechanical pump. Over a 4 hour cycle, the concentration of 2-chloro-3, 3, 3-trifluoropropene dropped to 28 ppm.

In summary, this example gave a 27.3% yield of 1234ze (E) and a 67.6% yield of 1233zd (E) based on the organic feed (1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene, and 1,1,1, 3-tetrachloropropene); 1234ze (E) yield was 32.2% based on HF feed, 1233zd (E) yield was 59.7%.

Example 4

In this example, the separation effect of a single phase separator and a two phase separator series process were compared.

Two phase separator series process as described in examples 1-3, two phase separator series schematic used as shown in figure 2, the operating temperature of the phase separator was-20 ℃. Stream 4 is the HCl removed stream from the first reactor and stream 8 is the HCl removed stream from the second reactor. In a two phase separator series process, stream 4 is fed to the first phase separator and stream 8 is fed to the second phase separator; the organic phase of the first phase separator also passes to the second phase separator. The HF layer and the organic layer were then collected and analyzed.

Single phase separator process using a separator as shown in fig. 3, streams 4 and 8 were simultaneously fed into a single phase separator, and then the HF layer and the organic layer were collected and analyzed, and the analysis results of the HF layer and the organic layer for single-stage phase separation and two-stage phase separation are shown in table 1. The yield of 1234ze (E) from the two-stage phase separation process was 0.139kg/hr, the yield of 1234ze (E) from the single-stage phase separation process was 0.101kg/hr, and the yield of 1234ze (E) from the two-stage phase separation process increased by 37.6%.

TABLE 1

The applicant states that the present invention is illustrated by the above examples of the process of the present invention, but the present invention is not limited to the above process steps, i.e. it is not meant that the present invention must rely on the above process steps to be carried out. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.

Claims

1. The method for simultaneously producing the trans-1-chloro-3, 3, 3-trifluoropropene and the trans-1, 3,3, 3-tetrafluoropropene is characterized in that at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene and 1,1,1, 3-tetrachloropropene and hydrogen fluoride are used as raw materials and are prepared through a gas phase reaction.

2. The method of claim 1, wherein the purity of the feedstock is from 99.5% to 99.8%;

preferably, the process is carried out using two reactors, the feed being introduced into the first reactor and subjected to a gas phase or liquid phase reaction to produce trans-1-chloro-3, 3, 3-trifluoropropene; feeding the heavy by-product produced in the first reactor into a second reactor, and carrying out gas-phase reaction with hydrogen fluoride in the presence of a catalyst to obtain trans-1, 3,3, 3-tetrafluoropropene.

3. The process according to claim 1 or 2, characterized in that the reaction in the first reactor is carried out with or without a catalyst;

preferably, when no catalyst is used in the reaction in the first reactor, the carrier for the reaction is activated carbon or corrosion-resistant metal mesh;

preferably, when a catalyst is used for the reaction in the first reactor, the catalyst is any one of iron trichloride, chromium (III) oxide, fluorinated chromium (III) oxide supported on fluorinated alumina, fluorinated chromium (III) oxide supported on activated carbon, fluorinated chromium (III) oxide supported on alumina or fluorinated chromium (III) oxide supported on aluminum fluoride, or a combination of at least two of them.

4. The method according to any one of claims 1 to 3, wherein after the reaction in the first reactor is completed, the residual hydrogen fluoride is recovered, the hydrogen chloride generated by the reaction is removed, and then the first organic phase product is obtained by separation through a first phase separator;

preferably, residual hydrogen fluoride is recovered by utilizing a hydrogen fluoride recycling tower;

5. The method according to any one of claims 1 to 4, wherein after the gas phase reaction in the second reactor is completed, the residual hydrogen fluoride is recovered, the hydrogen chloride generated by the reaction is removed, the reactant from which the hydrogen fluoride and the hydrogen chloride are removed is fed into a second phase separator, the first phase separator is separated to obtain a first organic phase product, the first organic phase product is fed into the second phase separator and is separated to obtain a second organic phase product;

6. The process of any one of claims 1-5, wherein the molar ratio of the total amount of at least two of 1,1,1,3, 3-pentachloropropane, 1,1,3, 3-tetrachloropropene, or 1,1,1, 3-tetrachloropropene to hydrogen fluoride in the first reactor is from 1:10 to 1: 30; preferably 1:15 to 1: 25; more preferably 1:20 to 1: 25;

preferably, the temperature of the reaction in the first reactor is 120-350 ℃; more preferably 140 ℃ to 300 ℃;

preferably, the pressure of the reaction in the first reactor is 0.5-3.5 MPa; more preferably 0.6-3.4 MPa;

preferably, the reaction time in the first reactor is 30 seconds to 3 hours; more preferably 60 seconds to 2 hours.

7. The process as claimed in any one of claims 1 to 6, wherein the temperature of the gas phase reaction in the second reactor is 150 ℃ to 400 ℃; more preferably 200-;

preferably, the pressure of the gas phase reaction in the second reactor is 0.5-1 MPa; more preferably 0.6-0.8 MPa;

preferably, the gas phase reaction time in the second reactor is 30-240 seconds; more preferably 45-100 seconds.

8. The process of any one of claims 1 to 7, wherein the catalyst in the second reactor is any one of or a combination of at least two of chromium (III) oxide, fluorinated chromium (III) oxide supported on fluorinated alumina, fluorinated chromium (III) oxide supported on activated carbon, fluorinated chromium (III) oxide supported on alumina, or fluorinated chromium (III) oxide supported on aluminum fluoride.

9. The process according to any one of claims 1 to 8, characterized in that the impurity 2-chloro-3, 3, 3-trifluoropropene in the final product trans-1-chloro-3, 3, 3-trifluoropropene is removed by molecular sieves or activated carbon or a combination of both.

10. The method of claim 9, wherein the molecular sieve is a 4A molecular sieve and/or a 5A molecular sieve;

preferably, the activated carbon is coconut shell activated carbon.