A process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials

Abstract

The present invention relates to a process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials, which comprises the following steps: Step 1: Take methane raw material and 1,1-dichlorotetrafluoroethane raw material for standby; Step 2: Place the methane raw material and 1,1-dichlorotetrafluoroethane raw material in Step 1 into a conventional cracking furnace for cracking reaction to produce R244bb and R1234yf products; Step 3: In the cracking reaction in Step 2, when CH4 and C2CL2F4 crack to release one H+ ion and one CL- ion to form one HCL molecule, the product is R244bb, and R244bb, which is C3H3CLF4, is an intermediate product for producing R1234yf; Step 4: When R244bb in the cracking process in Step 3 continues to remove one HCl, the products are R1234yf and HCL; It is beneficial to reduce the production cost of HFO series fluorochemical products, can greatly reduce energy consumption, expand the treatment route of by-product R114a in the industry, and turn waste into treasure.

Description

Technical Field

[0001] The present invention relates to a process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials. Background Art

[0002] Currently, the main production processes of R1234yf on the market are: hexafluoropropylene addition and elimination method, pentafluoropropane dehydrofluorination method, 2-chloro-3,3,3-trifluoropropene fluorine-chlorine exchange method, high-temperature pyrolysis method of monochloromethane and tetrafluoroethylene, synthesis method of hexafluoropropane and pentafluoropropane, etc.

[0003] Among the domestic R1234yf production enterprises, the hexafluoropropylene addition and elimination method is adopted, and Huanxin Fluorine Materials adopts the 2-chloro-3,3,3-trifluoropropene fluorine-chlorine exchange method. The common disadvantages of these processes are high upstream raw material costs, large corrosion of equipment by HF generated during production, high tail gas treatment costs, and difficulties in meeting environmental protection standards. Summary of the Invention

[0004] The purpose of the present invention is to provide a process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials in view of the defects and deficiencies of the prior art.

[0005] The process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials according to the present invention comprises the following steps:

[0006] Step 1: Take methane raw material and 1,1-dichlorotetrafluoroethane raw material and set aside.

[0007] Step 2: Place the methane raw material and 1,1-dichlorotetrafluoroethane raw material in Step 1 into a conventional pyrolysis furnace for pyrolysis reaction to generate R244bb and R1234yf products.

[0008] Step 3: In the pyrolysis reaction in Step 2, when CH4 and C2CL2F4 pyrolyze to release one H+ ion and one CL- ion to form one HCL molecule, the product is R244bb, and R244bb is C3H3CLF4.

[0009] Step 4: When R244bb in the pyrolysis process in Step 3 continues to remove one HCL, the products are R1234yf and HCL.

[0010] Further, the temperature of the conventional pyrolysis furnace in Step 2 is 600°C - 800°C.

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

[0012] CF3CCL2F + CH 4高温裂解CF3CCLFCH3 (R244bb) → CF3CF=CH2 (R1234yf)

[0013] Further, the reaction process of the main reaction in Step 2 is as follows:

[0014]

[0015] CL· + CH4 --- CH3· + HCL

[0016]

[0017] Further, the side reaction process in Step 2 is as follows:

[0018]

[0019] The beneficial effects of the present invention are as follows: A process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials according to the present invention adopts a method for producing the fourth-generation refrigerant HFO with low cost, and at the same time changes the nature of R114A from a fluorination production waste to a raw material for producing R1234yf, improving the environmental protection performance of the fluorination industry production; it is beneficial to reducing the production cost of HFO series fluorochemical products, can greatly reduce energy consumption, expand the treatment route of by-product R114a in the industry, and turn waste into treasure. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0021] Figure 1 is the hydrogen spectrum analysis map of the seventh sampling in Experiment 1 in Example 1 of the hydrogen spectrum analysis map in the present invention;

[0022] Figure 2 is the analysis result analysis map of the seventh sampling in Experiment 1 in Example 1 of the hydrogen spectrum analysis map in the present invention.

[0023] Figure 3 is the hydrogen spectrum analysis map of the fourth sampling in Experiment 2 in Example 2 of the hydrogen spectrum analysis map in the present invention;

[0024] Figure 4 is the analysis result analysis map of the fourth sampling in Experiment 2 in Example 2 of the hydrogen spectrum analysis map in the present invention;

[0025] Figure 5 is the analysis map of the hydrogen spectrum analysis map of the third sampling in Experiment 3 in Example 3 of the hydrogen spectrum analysis map in the present invention;

[0026] Figure 6It is the analysis chart of the third sampling in Experiment 3 in the legend of the hydrogen spectrum analysis chart in the present invention:

[0027] Figure 7 It is the analysis chart of the hydrogen spectrum analysis of the fourth sampling in Experiment 3 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0028] Figure 8 It is the analysis chart of the analysis result of the fourth sampling in Experiment 3 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0029] Figure 9 It is the analysis chart of the hydrogen spectrum analysis of the fourth sampling in Experiment 4 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0030] Figure 10 It is the analysis chart of the analysis result of the fourth sampling in Experiment 4 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0031] Figure 11 It is the analysis chart of the hydrogen spectrum analysis of the fifth sampling in Experiment 4 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0032] Figure 12 It is the analysis chart of the analysis result of the fifth sampling in Experiment 4 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0033] Figure 13 It is the analysis chart of the hydrogen spectrum analysis of the sixth sampling in Experiment 4 in the legend of the hydrogen spectrum analysis chart in the present invention;

[0034] Figure 14 It is the analysis chart of the analysis result of the sixth sampling in Experiment 4 in the legend of the hydrogen spectrum analysis chart in the present invention. Specific Embodiment

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

[0036] A process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials according to the present specific embodiment adopts the following steps:

[0037] Step 1: Take methane raw material and 1,1-dichlorotetrafluoroethane raw material for standby;

[0038] Step 2: Place the methane raw material and 1,1-dichlorotetrafluoroethane raw material in Step 1 in a conventional cracking furnace for cracking reaction to generate R244bb and R1234yf products;

[0039] Step 3: In the cracking reaction in Step 2, when CH4 and C2CL2F4 undergo cracking to release one H+ ion and one CL- ion, generating one HCL molecule, the product is R244bb, and R244bb is C3H3CLF4;

[0040] Step 4: When R244bb in the cracking process in Step 3 continues to eliminate one HCl, the products are R1234yf and HCL.

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

[0042] Furthermore, the reaction equation of the main reaction in Step 2 is as follows:

[0043] CF3CCL2F + CH 4高温裂解 CF3CCLFCH3 (R244bb) → CF3CF=CH2 (R1234yf)

[0044] Furthermore, the reaction process of the main reaction in Step 2 is as follows:

[0045]

[0046] CL· + CH4 --- CH3· + HCL

[0047]

[0048] Furthermore, the side reaction process in Step 2 is as follows:

[0049]

[0050] The present invention is illustrated as follows:

[0051] The present invention conducts experiments on the reaction of R114 + CH4 under different conditions. A total of multiple experiments are carried out. After 6 hours of reaction, the experiment is stopped, and the R114A raw material is recovered.

[0052] (1) Reaction system conditions: Tube furnace Φ50xΦ50x1000, three-stage, heating section 900, central constant temperature zone calculated as 300, volume 0.147L.

[0053] (2) Experimental process: After the tube furnace is heated to the set temperature, start feeding R114A, adjust to the set feed rate, collect and analyze the decomposed components of R114A when heated. After the R114A feed is stable, start feeding CH4, adjust to the set flow rate, and collect and analyze the composition of the product gas under different conditions.

[0054] (3) Experimental data:

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] (4) Analysis of experimental results:

[0070] (4.1) R114A starts to decompose at 550 degrees. The higher the temperature, the higher the decomposition ratio.

[0071] (4.2) At 550 degrees, no R1234yf product is generated, but the selectivity of R244bb is as high as about 94%. In large-scale production, the reaction can be carried out in two steps. First, convert R114A and CH4 into R244bb, and then convert R244bb into the target product R1234yf to achieve high production efficiency.

[0072] (4.3) At 600 degrees, the reaction can generate R1234yf, but the ratio is low, about 1.2 - 1.5%.

[0073] (4.4) At 700 degrees, the ratio of R1234yf generated increases, and the content reaches about 11%. However, R114A is almost completely decomposed, and there is obvious tar in the exhaust gas. A large amount of black substances appear when the exhaust pipe enters the water absorption.

[0074] (4.5) At 600 degrees, adding a catalyst is of no help to the reaction.

[0075] (4.6) Increasing the feed ratio of R114A at the same temperature cannot increase the conversion rate of R1234yf;

[0076] (4.7) Under the same conditions, increasing the feed rate of R114A and CH4, that is, increasing the space velocity and reducing the residence time, will result in a decrease in the content of R1234yf and a decrease in the conversion rate.

[0077] (4.8) Under the same conditions, increasing the reaction concentration of methane is beneficial to the formation of the product R244B component, and the component concentration of R1234yf formed decreases. When the methane feed ratio is close to 1.5 times the theoretical calculation ratio, it is beneficial to the formation of R1234yf.

[0078] In the present invention, for the first legend of the hydrogen spectrum analysis chart, the seventh sampling analysis chart of Experiment 1: The hydrogen spectrum analysis chart is as Figure 1 shown; the analysis results are as Figure 2 shown.

[0079] In the present invention, for the second legend of the hydrogen spectrum analysis chart, the fourth sampling analysis chart of Experiment 2: The hydrogen spectrum analysis chart is as Figure 3 shown; the analysis results are as Figure 4 shown.

[0080] In the present invention, for the third legend of the hydrogen spectrum analysis chart, the third sampling analysis chart of Experiment 3: The hydrogen spectrum analysis chart is as Figure 5 shown; the analysis results are as Figure 6 shown.

[0081] In the present invention, for the fourth legend of the hydrogen spectrum analysis chart, the fourth sampling analysis chart of Experiment 3: The hydrogen spectrum analysis chart is as Figure 7 shown; the analysis results are as Figure 8 shown.

[0082] In the present invention, for the fifth legend of the hydrogen spectrum analysis chart, the fourth sampling analysis chart of Experiment 4: The hydrogen spectrum analysis chart is as Figure 9 shown; the analysis results are as Figure 10 shown.

[0083] In the present invention, for the sixth legend of the hydrogen spectrum analysis chart, the fifth sampling analysis chart of Experiment 4: The hydrogen spectrum analysis chart is as Figure 11 shown; the analysis results are as Figure 12 shown.

[0084] In the present invention, for the seventh legend of the hydrogen spectrum analysis chart, the sixth sampling analysis chart of Experiment 4: The hydrogen spectrum analysis chart is as Figure 13 shown; the analysis results are as Figure 14 shown.

[0085] In the present invention, the main products obtained by the high-temperature pyrolysis of methane and 1,1-dichlorotetrafluoroethane (R114a) are tris(tetra)fluorochloropropane (R244bb), R1234yf, and HCl. The present invention is a method for producing the fourth-generation refrigerant HFO at low cost, while expanding the use of the by-product R114A from fluorination production as a raw material through incineration treatment, improving environmental performance; it is beneficial to reducing the production cost of HFO series fluorochemical products, can greatly reduce energy consumption, expand the treatment route of by-product R114a in the industry, and turn waste into treasure.

[0086] The effects of the present invention: It is beneficial to finding a low-cost method for producing HFO series products and expanding the treatment route of by-product R114a in the fluorination industry.

[0087] In laboratory experiments, the R1234yf product can achieve a conversion rate of 16% during the single-pass conversion of R114A. In large-scale production, optimized process design, recycling of raw materials, and full heat exchange can be adopted for continuous production to achieve an ideal yield.

[0088] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made according to the characteristics and principles described in the scope of the present invention patent application are included in the scope of the present invention patent application.

Claims

1. A process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials, characterized in that: Adopt the following steps: Step 1: Take methane raw material and 1,1-dichlorotetrafluoroethane raw material for standby; Step 2: Place the methane raw material and 1,1-dichlorotetrafluoroethane raw material in Step 1 into a conventional cracking furnace. The temperature of the conventional cracking furnace is 600°C - 800°C, and carry out a cracking reaction to generate R244bb and R1234yf products; Step 3: In the cracking reaction in Step 2, when CH4 and C2CL2F4 split off one H+ ion and one CL- ion to generate one HCL molecule, the product is R244bb. The structural formula of R244bb is CF3CCLFCH3, and the molecular formula of R244bb is C3H3CLF4; Step 4: When R244bb in the cracking process in Step 3 continues to remove one HCl, the products are R1234yf and HCL. The structural formula of R1234yf is CF3CF=CH2.

2. A process for co-producing R244bb and R1234yf using CH4 and C2CL2F4 as raw materials, characterized in that: The reaction formula of the main reaction in Step 2 is as follows:

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