A CH 4 and C 2 CL 3 F 3 Process for preparing R1233xf products using as raw materials

Abstract

The invention relates to a process for preparing R1233xf products by using CH4 and C2CL3F3 as raw materials, and the process comprises the following steps: step 1: taking a reaction amount of methane and 1,1,1-trichlorotrifluoroethane raw materials for standby use; step 2: placing the methane and 1,1,1-trichlorotrifluoroethane raw materials in step 1 in a cracking furnace for cracking reaction to generate R243ab and R1233xf products; step 3: in the cracking reaction in step 2, when CH4 and C2CL3F3 are cracked to release a H + ions and a CL ‑ ion, when a HCL molecule is generated, the product is R243ab, and R243ab is C3H3CL2F3; Step 4: when R243ab continues to remove one HCl during the cracking process, the products are R1233xf and HCL; it has a method for producing 2-chloro-3,3,3-trifluoropropene at a low cost, and has the advantage of expanding the fluorination product R113a to be used as a raw material.

Description

Technical Field

[0001] The invention relates to the technical field of water cups, and in particular to a process for preparing an R1233xf product by using CH4 and C2CL3F3 as raw materials. Background Art

[0002] The main applications of 2-chloro-3,3,3-trifluoropropene (R1233xf) are: first, it can be used in the synthesis of the new refrigerant 2,3,3,3-tetrafluoropropene (HFO-1234yf); second, it can be used in the synthesis of pharmaceutical intermediates.

[0003] R1233xf is a monomer that can be used to synthesize HFO-1234yf. Chlorotrifluoropropylene can be used to prepare HFO-1234yf. As a single refrigerant, hydrofluoroolefin HF0-1234yf has excellent environmental parameters, such as GWP = 4, ODP = 0, life cycle (LCCP) is lower than HFC-134a, and system performance is better than HFC-134a.

[0004] More importantly, HFP-1234yf, as a new generation of refrigerant, can be used in automotive MAC systems, and automakers do not need to replace the vehicle system. HFO-1234yf is not only a refrigerant, but also an effective heat transfer medium, propellant, foaming agent, blowing agent, gaseous dielectric, sterilization carrier, particle removal fluid, carrier fluid, polishing abrasive, displacement desiccant and power cycle working fluid, and has a wide range of uses.

[0005] Currently, the main production processes of R1233xf on the market are: one is to produce it through fluorination of 1,1,1,2,3-pentachloropropane; the other is to produce it through polymerization, liquid phase chlorination, fluorination and other processes of ethylene and carbon tetrachloride.

[0006] The common disadvantages of the above two traditional preparation processes are: first, the upstream raw material cost is high, the HF generated during production is highly corrosive to equipment, the exhaust gas treatment cost is high, and it is difficult to meet environmental protection standards.

[0007] The main products obtained by high temperature cracking of methane and 1,1,1-trichlorotrifluoroethane (R113a) are 2,2-dichloro-1,1,1-trifluoropropane (R243ab), R1233xf and HCL. R113a, as a CFC series, has a wide range of uses as an intermediate of pesticides, cleaning agents and foaming agents. However, due to the ozone depletion potential of R113a (ODP=0.9, global warming coefficient value (GWP=1.551) and the current market capacity saturation, the preparation of R1233xf as an intermediate of R1234yf by cracking with methane has a positive significance for expanding the application market of R113a. Summary of the invention

[0008] The purpose of the present invention is to provide a process for preparing R1233xf product using CH4 and C2CL3F3 as raw materials in view of the defects and shortcomings of the prior art.

[0009] The process for preparing R1233xf product using CH4 and C2CL3F3 as raw materials of the present invention adopts the following steps:

[0010] Step 1: Take the reacted amount of methane and 1,1,1-trichlorotrifluoroethane raw materials and set aside;

[0011] Step 2: placing the methane and 1,1,1-trichlorotrifluoroethane raw materials in step 1 in a cracking furnace to perform a cracking reaction to generate R243ab and R1233xf products;

[0012] Step 3: In the cracking reaction in step 2, when CH4 and C2CL3F3 are cracked to release a H + ions and a CL - ion, when an HCL molecule is generated, the product is R243ab, and R243ab is C3H3CL2F3, which is the intermediate product in the preparation of R1233xf;

[0013] Step 4: When R243ab continues to remove HCl during the cracking process, the products are R1233xf and HCL;

[0014] Furthermore, the temperature of the cracking furnace in step 2 is 500°C-600°C.

[0015] Furthermore, the reaction formula of the main reaction in step 3 and step 4 is as follows:

[0016] CF3CCL3+CH4 高温裂解 CF3CCL2CH3(R243ab)---CF3CCL=CH2(R1233xf)+HCL;

[0017] Further, the reaction process in step 3 and step 4 is as follows:

[0018]

[0019] CL·+CH4---CH3·+HCL

[0020]

[0021]

[0022] Furthermore, the side reaction process in step 3 and step 4 is as follows:

[0023]

[0024]

[0025]

[0026]

[0027]

[0028] The beneficial effects of the present invention are as follows: the process for preparing R1233xf products using CH4 and C2CL3F3 as raw materials of the present invention has the advantages of being able to produce R1233xf at low cost, and expanding the advantage of the fluorinated product R113a being able to be used as raw materials; it is conducive to finding low-cost production of HFO series products, expanding the use of the fluorinated product R113a, and R113a is converted into R1233xf products in a single process, with a conversion rate of up to 27%. In large-scale production, optimized process design, raw material recycling, and sufficient heat exchange can be adopted, and continuous production can be achieved to achieve an ideal yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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:

[0030] Figure 1 It is a sampling and analysis schematic diagram of the hydrogen spectrum analysis example 1 of the present invention;

[0031] Figure 2 It is a schematic diagram of the analysis results of the hydrogen spectrum analysis example 1 of the present invention. DETAILED DESCRIPTION

[0032] 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.

[0033] The process for preparing R1233xf product using CH4 and C2CL3F3 as raw materials described in this specific embodiment adopts the following steps:

[0034] Step 1: Take the reacted amount of methane and 1,1,1-trichlorotrifluoroethane raw materials and set aside;

[0035] Step 2: placing the methane and 1,1,1-trichlorotrifluoroethane raw materials in step 1 in a cracking furnace to perform a cracking reaction to generate R243ab and R1233xf products;

[0036] Step 3: In the cracking reaction in step 2, when CH4 and C2CL3F3 are cracked to release a H +ion and a Cl ion to generate an HCL molecule, the product is R243ab, R243ab is C3H3CL2F3; R243ab is C3H3C L F3 is an intermediate for the preparation of R1233xf;

[0037] Step 4: When R243ab continues to remove HCl during the cracking process, the products are R1233xf and HCL;

[0038] Furthermore, the temperature of the cracking furnace in step 2 is 500°C-600°C.

[0039] Furthermore, the reaction formula of the main reaction in step 3 and step 4 is as follows:

[0040] CF3CCL3+CH4 高温裂解 CF3CCL2CH3(R243ab)---CF3CCL=CH2(R1233xf)+HCL;

[0041] Further, the reaction process in step 3 and step 4 is as follows:

[0042]

[0043] CL·+CH4---CH3·+HCL

[0044]

[0045] Furthermore, the side reaction process in step 3 and step 4 is as follows:

[0046]

[0047] The present invention is further described with specific embodiments as follows:

[0048] The present invention conducts experiments on the reaction of R113a+CH4 under different conditions for multiple experiments. The experiment is stopped after 6 hours of reaction and the material is added again for the second experiment.

[0049] (1) Reaction system: Tube furnace Φ50xΦ50x1000, three-stage, heating section 900mm, central constant temperature zone 300, volume 0.147L;

[0050] (2) During the experiment, after the tube furnace was heated to the set temperature, R113a was fed in and the feed rate was adjusted to the set rate. The material was collected and analyzed for the thermal decomposition components of R113a. After the R113a feed was stabilized, CH4 was fed in and the flow rate was adjusted to the set rate. The material was collected and analyzed for the composition of the product gas under different conditions.

[0051] (3) Experimental data: (Note: the raw material composition of R113a: R113a: 99.79%, R114: 0.015%, R123: 0.006%).

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059] (4) Experimental results analysis:

[0060] (4.1) The reaction takes place in the range of 500°C to 560°C. There is almost no reaction below 500°C, and coke is generated above 600°C.

[0061] (4.2) The feed ratio of methane is twice the theoretical feed ratio, and the conversion rate is highest in the range of 500℃-560℃;

[0062] (4.3) In the range of 500℃-560℃, under the same feed ratio conditions, increasing the reaction temperature does not change the conversion rate of the target product significantly;

[0063] (4.4) In the experiment, the conversion rate of product R1233xf calculated by R113A can reach 27%;

[0064] (4.5) Under the same conditions, increasing the feed gas velocity does not help the conversion rate, but instead reduces it.

[0065] (5) Hydrogen spectrum analysis chart Example 1: The seventh sampling analysis chart and analysis results of Experiment 1, such as Figure 1 , Figure 2 shown.

[0066] The effects of the present invention are as follows: the present invention is conducive to finding low-cost production of HFO series products and expanding the use of fluorinated product R113a. In laboratory experiments, although the selectivity of the target product is only 38% at most, the selectivity of the intermediate of the product can reach more than 55%. Together with the target product components at the same time, the total effective selectivity is as high as more than 80%. In large-scale production processes, staged reactions can be adopted to first react CH4 with R113a to produce R234ab, and then convert R234ab into R1233xf products to improve conversion rate and selectivity, thereby achieving the effect of improving production efficiency.

[0067] 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 process for preparing R1233xf product using CH4 and C2CL3F3 as raw materials, characterized in that: Use the following steps: Step 1: Take the reacted amount of methane and 1,1,1-trichlorotrifluoroethane raw materials and set aside; Step 2: placing the methane and 1,1,1-trichlorotrifluoroethane raw materials in step 1 in a cracking furnace to perform a cracking reaction to generate R243ab and R1233xf products; Step 3: In the cracking reaction in step 2, when CH4 and C2CL3F3 are cracked to release a H + ions and a CL - ion, when an HCL molecule is generated, the product is R243ab, and R243ab is C3H3CL2F3, which is an intermediate in the preparation of R1233xf; Step 4: When R243ab continues to remove HCl during the cracking process, the products are R1233xf and HCL; The temperature of the cracking furnace in step 2 is 520°C-530°C, 570°C, 590°C.

2. A process for preparing R1233xf product using CH4 and C2CL3F3 as raw materials according to claim 1, characterized in that: The reaction formula of the main reaction in step 3 and step 4 is as follows: CF3CCl3+CH4→CF3CCl2CH3(R243ab)+HCl→CF3CCl=CH2(R1233xf)+2HCl.

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