阅读说明：本技术 一种液相法管道化连续分离生产氟化烷烃的方法 (Method for producing fluorinated alkane through liquid phase method pipelining continuous separation ) 是由 赵恒军 钱超 葛新 童绍丰 沈涛 潘国东 于 2019-10-09 设计创作，主要内容包括：本发明一种液相法管道化连续分离生产氟化烷烃的方法,包括以下步骤：(1)将原料从管道化反应器的入口泵入；(2)在管道化反应器内,在氟化催化剂存在下,氯化烷烃与氟化剂在所述管道化反应器内接触,流经加热段组,加热至相应的氟化反应的温度,进行氟化反应,然后再流经冷却段组；(3)所述反应液流经所述管道化反应器进行氟化反应后,进行预分离,分离出第一气相料,将所述第一气相料泵入纯化装置；(4)所述第一气相料在所述纯化装置中进行分离程序后,分离出所述氟化烷烃。本发明通过提供一种生产氟化烷烃的方法,使得氟化烷烃的生产具有在线反应量小、安全隐患小、反应便于控制、可连续生产、生产成本低的特点。(The invention relates to a method for producing fluorinated alkane by liquid phase method pipelining continuous separation, which comprises the following steps: (1) pumping the raw material from the inlet of the pipeline reactor; (2) in a pipeline reactor, in the presence of a fluorination catalyst, chlorinated alkane is contacted with a fluorinating agent in the pipeline reactor, flows through a heating section group, is heated to the corresponding fluorination reaction temperature, carries out fluorination reaction, and then flows through a cooling section group; (3) after the reaction liquid flows through the pipeline reactor for fluorination reaction, pre-separation is carried out, a first gas phase material is separated out, and the first gas phase material is pumped into a purification device; (4) separating the fluorinated alkane from the first gas phase material after the separation procedure in the purification device. The invention provides the method for producing fluorinated alkane, so that the production of fluorinated alkane has the characteristics of small online reaction amount, small potential safety hazard, convenient reaction control, continuous production and low production cost.)

1. A method for continuously separating and producing fluorinated alkane in a pipeline way by a liquid phase method, which is characterized in that chlorinated alkane and hydrogen fluoride react in a pipeline reactor under the condition of a fluorination catalyst to obtain the fluorinated alkane, and the fluorinated alkane has the following general formula: CnH2n +2-x-yClxFy, wherein n is an integer of 1-3.

2. Method according to claim 1, characterized in that it comprises the following steps:

(1) pumping raw materials from an inlet of a pipeline reactor, wherein the pipeline reactor comprises at least two groups of heating section groups and a group of cooling section groups, and the heating section groups at least comprise a heating section connected in parallel or in series; the cooling section group is arranged at the tail end of the pipeline reactor, the raw materials comprise chlorinated alkane, a fluorinating agent and a fluorination catalyst, the fluorinating agent comprises hydrogen fluoride, and the raw materials are mixed into reaction liquid in the pipeline reactor;

(2) filling pressurized gas into a pipeline reactor to 0.2-3MPa, and enabling the reaction liquid to flow through the pipeline reactor at a flow rate of 0.1-3m/s, so that chlorinated alkane and a fluorinating agent are contacted in the pipeline reactor in the presence of the fluorination catalyst, flow through a heating section group, are heated to the corresponding fluorination reaction temperature, are subjected to fluorination reaction, and then flow through a cooling section group to obtain a reaction liquid material flow containing an intermediate product and the fluorinated alkane;

(3) after the reaction liquid flows through the pipeline reactor for fluorination reaction, the reaction effluent is pumped out from an outlet of the pipeline reactor to become reaction effluent, and the reaction effluent is pumped to a first gas-liquid separation device for pre-separation to be separated into a first gas phase material and a first liquid phase material, wherein the first gas phase material contains fluorinated alkane, and the first liquid phase material contains the fluorination catalyst, and unreacted chlorinated alkane and the hydrogen fluoride; pumping the first liquid phase material back to the pipeline reactor, and pumping the first gas phase material into a purification device;

(4) and after the first gas phase material is subjected to a separation procedure in the purification device, separating the fluorinated alkane to obtain a finished product.

3. The method of claim 2, wherein the temperature of the fluorination reaction is 50-130 ℃, and the temperature of the fluorination reaction of the heating section group is increased from the inlet to the outlet of the pipeline reactor, so that the reaction liquid flows from the inlet to the outlet of the pipeline reactor, and the temperature of the fluorination reaction is gradually increased when the fluorination reaction is carried out.

4. The method according to claim 2, wherein intermediate devices are arranged between the heating section groups, the intermediate devices are connected with corresponding gas-liquid separation devices through pipelines, the reactant liquid streams flow through the intermediate devices, and part of the intermediate products are gasified to form intermediate product streams which flow to the corresponding gas-liquid separation devices to be separated to obtain the corresponding intermediate products.

5. The method according to claim 2, wherein the canalization reactor is one or a combination of a straight tube reactor, a coil tube reactor, a U-tube reactor, a multi-tube reactor, a loop tube reactor, and the like.

6. The method of claim 2, 3 or 4, wherein the supplemental hydrogen fluoride is fed into the ducted reactor from the front end of the heating section bank of the ducted reactor such that the molar ratio of hydrogen fluoride to the intermediate product in the ducted reactor is at least 20: 1.

7. the method of claim 2, 3 or 4, wherein the intermediate product is added to the ducted reactor from the front end of the heating section bank of the ducted reactor such that the molar ratio of hydrogen fluoride to the intermediate product in the ducted reactor is (40-75): 1.

8. the method of claim 1, wherein the chlorinated alkane and the fluorination catalyst are mixed in a mass ratio (2-10): 1, pumping at a flow rate of 0.1-3m/s after mixing in proportion, preheating to 40-100 ℃, pumping hydrogen fluoride at a flow rate of 0.1-3m/s, and preheating to 40-100 ℃.

9. The method of claim 2, wherein the feedstock is mixed in a static mixer and pumped into the pipeline reactor.

10. The process of claim 1, wherein the fluorination catalyst is a transition metal chlorofluoride comprising at least one of antimony pentachloride, antimony chlorofluoride, tin tetrachloride, titanium tetrachloride and mercury fluoride, the transition metal being represented by M, and the general formula of the fluorination catalyst is MClxFy.

Technical Field

The invention relates to a method for producing fluorinated alkane by liquid phase method pipelining continuous separation.

Background

Fluorinated alkanes, as a class of substances, have a number of different applications, including as chemical intermediates, blowing agents, and refrigerants.

With the increasing need for environmentally compatible fluorocarbons for use as refrigerants, blowing agents and solvents, there is a continuing incentive to economically attractive solutions to their production. The fluorinated alkanes produced by the process of the present invention may be used as refrigerants, blowing agents or solvents per se, or as intermediates in the production of other halogenated alkanes that meet the same requirements.

The existing liquid phase preparation technology of the fluoroalkane usually adopts a kettle type liquid phase fluorination method, materials are continuously refluxed and back mixed in the method, the system is uniform, the product concentration is higher, the reverse progress of the reaction can be promoted, the forward promotion of the reaction is not facilitated, the kettle type channeling reaction is not suitable, and the capacity utilization of single equipment is limited. The tubular reactor is a one-way reaction without back mixing, the product can be removed in time after passing through the gas-liquid separator, the forward proceeding of the reaction is facilitated, and meanwhile, the tubular reactor is connected through the gas-liquid separator in a channeling mode, so that the capacity of single equipment can be greatly improved.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for producing fluorinated alkane. The method has the characteristics of small online reaction amount, small potential safety hazard, convenient control of reaction, continuous production and low production cost.

The purpose of the invention is realized as follows:

a method for producing fluorinated alkane by liquid phase method pipeline continuous separation, under the condition of fluorination catalyst, chlorinated alkane and hydrogen fluoride are reacted in a pipeline reactor to obtain the fluorinated alkane, and the fluorinated alkane has the following general formula: CnH2n +2-x-yClxFy, wherein n is an integer of 1-3.

Preferably, the method comprises the steps of:

(1) pumping raw materials from an inlet of a pipeline reactor, wherein the pipeline reactor comprises at least two groups of heating section groups and a group of cooling section groups, and the heating section groups at least comprise a heating section connected in parallel or in series; the cooling section group is arranged at the tail end of the pipeline reactor, the raw materials comprise chlorinated alkane, a fluorinating agent and a fluorination catalyst, the fluorinating agent comprises hydrogen fluoride, and the raw materials are mixed into reaction liquid in the pipeline reactor;

(2) filling pressurized gas into a pipeline reactor to 0.2-3MPa, and enabling the reaction liquid to flow through the pipeline reactor at a flow rate of 0.1-3m/s, so that chlorinated alkane and a fluorinating agent are contacted in the pipeline reactor in the presence of the fluorination catalyst, flow through a heating section group, are heated to the corresponding fluorination reaction temperature, are subjected to fluorination reaction, and then flow through a cooling section group to obtain a reaction liquid material flow containing an intermediate product and the fluorinated alkane;

(3) after the reaction liquid flows through the pipeline reactor for fluorination reaction, the reaction effluent is pumped out from an outlet of the pipeline reactor to become reaction effluent, and the reaction effluent is pumped to a first gas-liquid separation device for pre-separation to be separated into a first gas phase material and a first liquid phase material, wherein the first gas phase material contains fluorinated alkane, and the first liquid phase material contains the fluorination catalyst, and unreacted chlorinated alkane and the hydrogen fluoride; pumping the first liquid phase material back to the pipeline reactor, and pumping the first gas phase material into a purification device;

(4) and after the first gas phase material is subjected to a separation procedure in the purification device, separating the fluorinated alkane to obtain a finished product.

Preferably, the temperature of the fluorination reaction is 50-130 ℃, and the temperature of the fluorination reaction of the heating section group is increased from the inlet to the outlet of the pipeline reactor, so that the reaction liquid flows from the inlet to the outlet of the pipeline reactor, and the temperature of the fluorination reaction is gradually increased when the fluorination reaction is carried out.

Preferably, an intermediate device is arranged between the heating section groups, the intermediate device is connected with a corresponding gas-liquid separation device through a pipeline, the reactant liquid stream flows through the intermediate device, part of the intermediate product is gasified into an intermediate product stream, and the intermediate product stream flows to the corresponding gas-liquid separation device to be separated to obtain a corresponding intermediate product.

Further, the pipeline reactor is one or a combination of a straight tube type reactor, a coil type reactor, a U-shaped tube type reactor, a multi-tube type reactor, an annular tube type reactor and the like.

Preferably, a first intermediate device is arranged between the heating section groups, the first intermediate device is connected with the first gas-liquid separation device through a pipeline, and part of the fluorinated alkane is gasified into a product stream and flows to the first gas-liquid separation device.

Further, supplementing hydrogen fluoride into the ducted reactor from a front end of the heating section bank of the ducted reactor such that a molar ratio of hydrogen fluoride to the intermediate product in the ducted reactor is at least 20: 1.

further, supplementing the intermediate product into the pipelined reactor from a front end of the heating segment bank of the pipelined reactor such that a molar ratio of hydrogen fluoride to the chlorinated alkane within the pipelined reactor is (1-10): 1.

further, supplementing the intermediate product into the ducted reactor from the front end of the heating section bank of the ducted reactor such that the molar ratio of hydrogen fluoride to the intermediate product in the ducted reactor is (40-75): 1.

further, hydrogen fluoride is supplemented into the pipeline reactor at a speed of 0.2-2m/s from the front end of the heating section group of the pipeline reactor.

Preferably, before being pumped into the pipelining reactor, the chlorinated alkane and the fluorination catalyst are mixed according to a mass ratio (2-10): 1, pumping at a flow rate of 0.1-3m/s after mixing in proportion, preheating to 40-100 ℃, pumping hydrogen fluoride at a flow rate of 0.1-3m/s, and preheating to 40-100 ℃.

Preferably, the raw materials are mixed by a static mixer and then pumped into the pipeline reactor.

Preferably, the fluorination catalyst is transition metal chlorofluoride, including at least one of antimony pentachloride, antimony chlorofluoride, stannic chloride, titanium tetrachloride and mercury fluoride, wherein M represents the transition metal, and the general formula of the fluorination catalyst is MClxFy.

Preferably, the fluorination catalyst comprises antimony pentachloride or antimony chlorofluoride and has the general formula of SbCl_xF_yWherein x + y is 5, y<5。

Preferably, the temperature of the fluorination reaction is 50-130 ℃, and the pressure of the fluorination reaction is 0.6-2.5 MPa.

Preferably, solid matter in the liquid phase material is filtered out by a filtering device before the liquid phase material is pumped back to the pipelining reactor.

Further, the solid material is transferred to a fluorination catalyst reactivation apparatus for reactivation to yield a reactivated fluorination catalyst and pumped back to the pipeline reactor.

The invention has the following beneficial effects:

1. the reactor is a channeling reactor, and has high equipment utilization rate and high capacity.

2. The fluorination reaction of the invention is carried out in nearly plug flow, no back mixing, less side reaction, less equipment investment and stable product quality

3. The fluorinated alkane production method is a continuous separation production method, and can remove products in time to promote the forward propulsion of the reaction.

4. The method of the invention utilizes the characteristic of high mass transfer and heat transfer efficiency of the pipeline reactor to ensure that the fluorination reaction keeps higher conversion rate of raw materials under better reaction temperature and shorter retention time.

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.

In the present invention, the raw materials and equipment used are commercially available or commonly used in the art, unless otherwise specified. The methods in the following examples are conventional in the art unless otherwise specified.

Preparation example

A method for producing fluorinated alkane by liquid phase method pipeline continuous separation, under the condition of fluorination catalyst, chlorinated alkane and hydrogen fluoride are reacted in a pipeline reactor to obtain the fluorinated alkane, and the fluorinated alkane has the following general formula: CnH2n +2-x-yClxFy, wherein n is an integer of 1-3.

Preferably, the method comprises the steps of:

(1) pumping raw materials from an inlet of a pipeline reactor, wherein the pipeline reactor comprises at least two groups of heating section groups and a group of cooling section groups, and the heating section groups at least comprise a heating section connected in parallel or in series; the cooling section group is arranged at the tail end of the pipeline reactor, the raw materials comprise chlorinated alkane, a fluorinating agent and a fluorination catalyst, the fluorinating agent comprises hydrogen fluoride, and the raw materials are mixed into reaction liquid in the pipeline reactor;

(2) filling pressurized gas into a pipeline reactor to 0.2-3MPa, and enabling the reaction liquid to flow through the pipeline reactor at a flow rate of 0.1-3m/s, so that chlorinated alkane and a fluorinating agent are contacted in the pipeline reactor in the presence of the fluorination catalyst, flow through a heating section group, are heated to the corresponding fluorination reaction temperature, are subjected to fluorination reaction, and then flow through a cooling section group to obtain a reaction liquid material flow containing an intermediate product and the fluorinated alkane;

(3) after the reaction liquid flows through the pipeline reactor for fluorination reaction, the reaction effluent is pumped out from an outlet of the pipeline reactor to become reaction effluent, and the reaction effluent is pumped to a first gas-liquid separation device for pre-separation to be separated into a first gas phase material and a first liquid phase material, wherein the first gas phase material contains fluorinated alkane, and the first liquid phase material contains the fluorination catalyst, and unreacted chlorinated alkane and the hydrogen fluoride; pumping the first liquid phase material back to the pipeline reactor, and pumping the first gas phase material into a purification device;

(4) after the first gas phase material is subjected to a separation procedure in the purification device, separating out the fluorinated alkane to obtain a finished product;

preferably, the fluorination catalyst is antimony pentachloride or antimony chlorofluoride, and the general formula of the fluorination catalyst is SbCl_xF_yWherein x + y is 5, y<5；

Preferably, before being pumped into the pipelining reactor, the chlorinated alkane and the fluorination catalyst are mixed according to a mass ratio (2-10): 1, pumping at the flow rate of 0.1-3m/s after mixing in proportion, preheating to 40-100 ℃, and pumping hydrogen fluoride at the flow rate of 0.1-3m/s, preheating to 40-100 ℃; preferably, the raw materials are mixed by a static mixer and then pumped into the pipeline reactor; preferably, the reaction temperature is 50-130 ℃, and the pressure of the fluorination reaction is 0.6-2.5 MPa;

preferably, the temperature of the fluorination reaction is 50-130 ℃, the temperature of the fluorination reaction of the heating section group is increased sequentially from the inlet to the outlet of the pipeline reactor, so that the reaction liquid flows from the inlet to the outlet of the pipeline reactor, and the temperature of the fluorination reaction is gradually increased when the fluorination reaction is carried out;

preferably, an intermediate device is arranged between the heating section groups, the intermediate device is connected with a corresponding gas-liquid separation device through a pipeline, the reactant liquid stream flows through the intermediate device, part of the intermediate product is gasified into an intermediate product stream, and the intermediate product stream flows to the corresponding gas-liquid separation device to be separated to obtain a corresponding intermediate product;

further, supplementing hydrogen fluoride into the ducted reactor from a front end of the heating section bank of the ducted reactor such that a molar ratio of hydrogen fluoride to the intermediate product in the ducted reactor is at least 20: 1; further, supplementing the intermediate product into the ducted reactor from the front end of the heating section bank of the ducted reactor such that the molar ratio of hydrogen fluoride to the intermediate product in the ducted reactor is (40-75): 1; further, supplementing the intermediate product into the pipelined reactor from a front end of the heating segment bank of the pipelined reactor such that a molar ratio of hydrogen fluoride to the chlorinated alkane within the pipelined reactor is (1-10): 1;

preferably, an intermediate device is arranged between the heating section groups, the intermediate device is connected with a corresponding gas-liquid separation device through a pipeline, and part of the fluorinated alkane is gasified into a product flow and flows to the first gas-liquid separation device;

preferably, before the liquid phase material is pumped back to the pipelining reactor, solid matters in the liquid phase material are filtered out through a filtering device; further, the solid material is transferred to a fluorination catalyst reactivation apparatus for reactivation to yield a reactivated fluorination catalyst and pumped back to the pipeline reactor.

The following processes of the present invention and the prior art are compared by specifically synthesizing difluoromethane monochloride, difluoromethane and 1,1,1,3, 3-pentafluoropropane by way of examples.