A method for co-producing R244bb and R1234yf using R134a and dichloromethane as raw materials

Abstract

The present invention specifically relates to a process technology method for co-producing R244bb and R1234yf by using R134a and dichloromethane as raw materials, and adopts the following steps: step 1: taking R134a raw material and dichloromethane raw material for standby; step 2: placing the R134a raw material and dichloromethane in step 1 in a conventional cracking furnace for cracking reaction to generate R244bb and R1234yf products; step 3: in the cracking reaction in step 2, when CH2CL2 and C2H2F4 are cracked to release an H+ ion and a CL- ion to generate an HCL molecule, the product is R244bb, and R244bb is C3H3CLF4; step 4: in the cracking process of step 3, CH2CL2 releases two CL ‑ ions, C2H2F4 breaks apart to release two H + ions, the products are R1234yf and HCL; it extends the industrial chain of R134a, promotes the use of R134a as a raw material for the preparation of the new refrigerant R1234yf, and avoids the problem of high global warming potential caused by the direct use of R134a.

Description

Technical Field

[0001] The invention relates to the technical field, and in particular to a process technology method for co-producing R244bb and R1234yf by taking R134a and dichloromethane as raw materials. Background Art

[0002] my country's R1234yf production enterprises use the hexafluoropropylene addition elimination method, and Huanxin Fluoro Materials uses the 2-chloro-3,3,3-trifluoropropylene fluorine-chlorine exchange method. The common disadvantages of the above processes are high upstream raw material costs, HF generated during production, which is highly corrosive to equipment, high tail gas treatment costs, and difficulty in meeting environmental standards.

[0003] The main products obtained by high temperature cracking of dichloromethane and 1,1,1,2-tetrafluoroethane (R134a) are trifluorochloropropane (R244bb), R1234yf and HCL. The use of R134a as a refrigerant in the automotive industry has been banned in Europe. The invention is that R1234yf is obtained by high temperature cracking of R134a with dichloromethane, and is more widely used in the refrigeration industry. Summary of the invention

[0004] The object of the present invention is to provide a method for co-producing R244bb and R1234yf by using R134a and dichloromethane as raw materials in view of the defects and shortcomings of the prior art.

[0005] The method of the present invention using R134a and dichloromethane as raw materials to co-produce R244bb and R1234yf comprises the following steps:

[0006] Step 1: Take R134a raw material and dichloromethane raw material and set aside;

[0007] Step 2: placing the R134a raw material and dichloromethane in a conventional cracking furnace to carry out cracking reaction to generate R244bb and R1234yf products;

[0008] Step 3: In the cleavage reaction in step 2, when CH2CL2 and C2H2F4 cleave to release an H+ ion and a CL- ion to generate an HCL molecule, the product is R244bb, and R244bb is C3H3CLF4;

[0009] Step 4: In the cracking process of step 3, CH2CL2 is released into two CL - ions, C2H2F4 breaks apart to release two H + ions, the products are R1234yf and HCL.

[0010] Furthermore, the temperature of the conventional cracking furnace in step 2 is 600°C-800°C.

[0011] Further, the reaction formula of the main reaction of the cleavage reaction in step 2 is as follows:

[0012]

[0013] Further, the reaction of the cleavage reaction in step 2 is as follows:

[0014]

[0015] Furthermore, the side reaction process of the cleavage reaction in step 2 is as follows:

[0016]

[0017] CF3·+·CL→CCLF3

[0018]

[0019] The beneficial effects of the present invention are as follows: the method of the present invention for co-producing R244bb and R1234yf using R134a and dichloromethane as raw materials extends the industrial chain of R134a, promotes the use of R134a as a raw material for preparing the new refrigerant R1234yf, and avoids the problem of high global warming potential (GWP) caused by direct use of R134a. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application, but do not constitute an improper limitation of the present invention. In the drawings:

[0021] Figure 1 It is the hydrogen spectrum analysis spectrum analysis diagram of the third sampling of Experiment 1 in the hydrogen spectrum analysis spectrum example 1 of the present invention;

[0022] Figure 2 This is the analysis result analysis diagram of the third sampling of Experiment 1 in the hydrogen spectrum analysis example 1 of the present invention.

[0023] Figure 3 It is the hydrogen spectrum analysis diagram of the sixth sampling of Experiment 3 in the hydrogen spectrum analysis diagram example 2 of the present invention;

[0024] Figure 4 It is the analysis diagram of the sixth sampling analysis result of Experiment 3 in the second example of the hydrogen spectrum analysis diagram of the present invention;

[0025] Figure 5 It is an analysis diagram of the hydrogen spectrum analysis spectrum of the ninth sampling of Experiment 3 in the hydrogen spectrum analysis spectrum example 3 of the present invention;

[0026] Figure 6It is the analysis result analysis diagram of the ninth sampling of Experiment 3 in the hydrogen spectrum analysis diagram example 3 of the present invention;

[0027] Figure 7 It is the hydrogen spectrum analysis diagram of the twelfth sampling in Experiment 3 in the hydrogen spectrum analysis diagram example 4 of the present invention;

[0028] Figure 8 This is the analysis result analysis diagram of the twelfth sampling of Experiment 3 in the hydrogen spectrum analysis diagram example 4 of the present invention;

[0029] Fig. 9 It is the hydrogen spectrum analysis diagram of the eleventh sampling of Experiment 4 in the hydrogen spectrum analysis diagram example 5 of the present invention;

[0030] Fig.10 This is the analysis result analysis diagram of the eleventh sampling of Experiment 4 in the hydrogen spectrum analysis diagram example 5 of the present invention;

[0031] Fig.11 It is the hydrogen spectrum analysis diagram of the seventh sampling of Experiment 5 in the hydrogen spectrum analysis diagram example 6 of the present invention;

[0032] Fig.12 This is the analysis result analysis diagram of the seventh sampling of Experiment 5 in the hydrogen spectrum analysis diagram example 6 of the present invention;

[0033] Fig.13 It is the hydrogen spectrum analysis diagram of the sixth sampling of Experiment 5 in the hydrogen spectrum analysis diagram example 7 of the present invention;

[0034] Fig.14 This is the analysis result analysis diagram of the sixth sampling of Experiment 5 in the hydrogen spectrum analysis diagram example 7 of the present invention. DETAILED DESCRIPTION

[0035] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments, wherein the illustrative embodiments and descriptions are only used to explain the present invention but are not intended to limit the present invention.

[0036] The method described in this specific embodiment of the present invention is a method for co-producing R244bb and R1234yf using R134a and dichloromethane as raw materials, which adopts the following steps:

[0037] Step 1: Take R134a raw material and dichloromethane raw material and set aside;

[0038] Step 2: placing the R134a raw material and dichloromethane in a conventional cracking furnace to carry out cracking reaction to generate R244bb and R1234yf products;

[0039] Step 3: In the cleavage reaction in step 2, when CH2CL2 and C2H2F4 cleave to release an H+ ion and a CL- ion to generate an HCL molecule, the product is R244bb, and R244bb is C3H3CLF4;

[0040] Step 4: In the cracking process of step 3, CH2CL2 is released into two CL - ions, C2H2F4 breaks apart to release two H + ions, the products are R1234yf and HCL.

[0041] Furthermore, the temperature of the conventional cracking furnace in step 2 is 600°C-800°C.

[0042] Further, the reaction formula of the main reaction of the cleavage reaction in step 2 is as follows:

[0043]

[0044] Further, the reaction of the cleavage reaction in step 2 is as follows:

[0045]

[0046] Furthermore, the side reaction process of the cleavage reaction in step 2 is as follows:

[0047]

[0048] CF3·+·CL→CCLF3

[0049]

[0050] The present invention takes actual test examples for further explanation, which are as follows: the present invention conducts experiments on the reaction of R134a+CH2CL2 under different conditions, and conducts multiple experiments in total. The experiment is stopped after 6 hours of reaction, and the raw materials are added again.

[0051] 1. Reaction system: Tube furnace Φ50xΦ50x1000, three-stage, heating section 900, central constant temperature zone 300, volume 0.147L

[0052] 2. Experimental process: After the tubular furnace is heated to the set temperature, CH2CL2 is fed in and adjusted to the set feed rate. The material is collected and analyzed for the thermal decomposition components of CH2CL2. After the CH2CL2 feed is stable, R134a is fed in and adjusted to the set flow rate. The material is collected and analyzed for the composition of the product gas under different conditions.

[0053] 3. Experimental data:

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060] 4. Experimental results analysis:

[0061] (1) R134a and CH2CL2 begin to decompose at 400-700 degrees. The higher the temperature, the higher the decomposition ratio; but the product components are different in different temperature ranges.

[0062] (2) In the range of 400-600 degrees, the proportion of R1234yf generated by the reaction is greater than that of R244bb; the conversion rate of R1234yf can reach 18%;

[0063] (3) In the range of 600-700 degrees, the proportion of R1234yf generated is lower than that of R244bb, and the conversion rate of R244bb is about 38% calculated based on dichloromethane.

[0064] (4) Increasing the feed ratio of R134a at the same temperature is beneficial to increasing the conversion rate of R244bb and reducing the conversion rate of R1234yf.

[0065] (5) Under the temperature condition of about 680 degrees, the feed amount of R134a and CH2CL2 is increased, that is, the space velocity increases, the residence time decreases, the content of R1234yf and R244bb increases, and the conversion rate increases.

[0066] (6) Under the same conditions, when the feed ratio of R134a to CH2CL2 is greater than the theoretical ratio, it is beneficial to the formation of R244 product. When the feed ratio is less than the theoretical ratio, it is beneficial to the formation of R1234yf.

[0067] (7) During the experiment, by adjusting the feed ratio of R134a to CH2CL2, the selectivity of the target product R244bb was as high as 84.4%, and the selectivity of the target product R1234yf was as high as 69.09%.

[0068] 5. Hydrogen spectrum analysis The analysis of the spectrum is as follows:

[0069] In the present invention, the hydrogen spectrum analysis spectrum example 1, the third sampling analysis diagram of experiment 1: the hydrogen spectrum analysis spectrum, such as Figure 1 The analysis results are shown in Figure 2 shown.

[0070] In the present invention, the hydrogen spectrum analysis spectrum example 2, the sixth sampling analysis diagram of experiment 3: the hydrogen spectrum analysis spectrum, such as Figure 3 The analysis results are shown in Figure 4 shown.

[0071] In the present invention, the hydrogen spectrum analysis spectrum example 3, the 9th sampling analysis diagram of experiment 3: the hydrogen spectrum analysis spectrum, such as Figure 5 The analysis results are shown in Figure 6 shown.

[0072] In the present invention, the hydrogen spectrum analysis spectrum example 4, the 12th sampling analysis diagram of experiment 3: the hydrogen spectrum analysis spectrum, such as Figure 7 The analysis results are shown in Figure 8 shown.

[0073] In the present invention, the hydrogen spectrum analysis spectrum example 5, the 11th sampling analysis diagram of experiment 4: the hydrogen spectrum analysis spectrum, such as Fig. 9 The analysis results are shown in Fig.10 shown.

[0074] In the present invention, the hydrogen spectrum analysis spectrum example 6, the seventh sampling analysis diagram of experiment 5: the hydrogen spectrum analysis spectrum, such as Fig.11 The analysis results are shown in Fig.12 shown.

[0075] In the present invention, the hydrogen spectrum analysis spectrum example 7, the sixth sampling analysis diagram of experiment 5: the hydrogen spectrum analysis spectrum, such as Fig.13 The analysis results are shown in Fig.14 shown.

[0076] Effect of this patent: The present invention is conducive to finding low-cost production of HFO series products, extending the industrial chain of R134a, and promoting the use of R134a as a raw material for preparing the new refrigerant R1234yf. In laboratory experiments, the conversion rate of the product R244bb can reach about 40% calculated by CH2CL2, and the conversion rate of R1234yf reaches 16%. In large-scale production, optimized process design can be used to solve the problem of low single conversion rate. The raw materials that have not reacted in a single time can improve the conversion rate of the reactants through the principle of low-temperature separation and reuse.

[0077] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the features and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A method for co-producing R244bb and R1234yf using R134a and dichloromethane as raw materials, characterized in that: Use the following steps: Step 1: Take R134a raw material and dichloromethane raw material and set aside; Step 2: placing the R134a raw material and dichloromethane in step 1 in a conventional cracking furnace for cracking reaction to generate R244bb and R1234yf products; the temperature of the conventional cracking furnace is 550°C, 560°C, 570°C, 580°C, 620°C-650°C; Step 3: In the cleavage reaction in step 2, when CH2CL2 and C2H2F4 cleave to release an H+ ion and a CL- ion to generate an HCL molecule, the product is R244bb, and R244bb is C3H3CLF4; Step 4: In the cracking process of step 3, CH2CL2 is released into two CL - ions, C2H2F4 breaks apart to release two H + ions, the products are R1234yf and HCL.

2. The method for co-producing R244bb and R1234yf using R134a and dichloromethane as raw materials according to claim 1, characterized in that: The reaction formula of the main reaction of the cleavage reaction in step 2 is as follows:

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