Fluorination device for tetrafluoroethane catalyst

Abstract

The fluorination device is characterized in that a nitrogen storage tank (5) is communicated with a nitrogen heater (1), the nitrogen heater (1) is connected with a conveying pipe II (8), a hydrogen fluoride storage tank (9) is connected with a conveying pipe III (11), the conveying pipe II (8) and the conveying pipe III (11) are combined into a mixed pipeline (12) which is communicated with an inlet of a fluorination reactor (4), and the mixed pipeline (12) is communicated with an outlet of the fluorination reactor (4). The DPA polyurethane catalyst storage tank (13) is communicated with an inlet of the fluorination reactor (4), the fluorination reactor (4) is communicated with the mixing pipeline (12) through the conveying pipeline (16) to form a circulation branch (3), and an electric heating element (17) of the electric heater (2) is installed on the fluorination reactor (4). According to the utility model, the consumption of hydrogen fluoride and nitrogen can be reduced in a circulating manner, the normal use of energy is maintained, and meanwhile, the circulating use of mixed gas can shorten the fluorination regeneration time.

Description

Technical Field

[0001] The utility model relates to a fluorination device for tetrafluoroethane catalyst. Background Art

[0002] Tetrafluoroethane (R134a) is one of the good and internationally recognized substitutes for CFC-12. It has excellent physical and chemical properties and an ozone depletion potential of 0. It is mainly used in refrigeration units of automobile air conditioners, household refrigerators and large industrial air conditioners. Especially in automobile air conditioners, due to its non-flammability, R134a is almost the only substitute so far. The key to the gas phase preparation of R134a lies in the activity, stability and service life of the catalyst. However, due to the high-temperature carbonization of chlorinated alkane compounds generated by the fluorination reaction, the activity of the catalyst will decrease after a period of use, resulting in a decrease in reaction efficiency and conversion rate, and even causing catalyst deactivation. Therefore, the R134a catalyst needs to be regenerated and fluorinated after running for a period of time. The regeneration process mainly involves introducing air at a certain temperature and pressure, then introducing a mixture of nitrogen and hydrogen to reduce the catalyst, and finally introducing a mixture of nitrogen and hydrogen fluoride for fluorination. Regeneration fluorination uses a large amount of nitrogen and hydrogen fluoride, as well as a large amount of heat, and the process takes a long time. Utility Model Content

[0003] The utility model provides a fluorination device for tetrafluoroethane catalyst, which can reduce the consumption of hydrogen fluoride and nitrogen in a circulation manner, maintain normal energy use, and simultaneously the circulation use of mixed gas can shorten the fluorination regeneration time.

[0004] The utility model adopts the following technical scheme: a fluorination device for tetrafluoroethane catalyst, which comprises a nitrogen heater, an electric heater, a circulating fan and a fluorination reactor, wherein the outlet of a nitrogen gas storage tank is connected to one end of a delivery pipe I through a switch valve I, the other end of the delivery pipe I is connected to an inlet of the nitrogen heater, the outlet of the nitrogen heater is connected to one end of a delivery pipe II, the outlet of a hydrogen fluoride gas storage tank is connected to the switch valve II and one end of a delivery pipe III in sequence, the other end of the delivery pipe II and the other end of the delivery pipe III are combined into a mixing pipeline and connected to the inlet of the fluorination reactor, the outlet of a DPA polyurethane catalyst storage tank is connected to the inlet of the fluorination reactor through the switch valve III and the delivery pipe IV in sequence, the outlet of the fluorination reactor is connected to the mixing pipeline through the delivery pipeline to form a circulation branch, and the electric heating element of the electric heater is installed on the fluorination reactor and can heat the fluorination reactor.

[0005] Furthermore, a circulation fan is installed on the circulation branch.

[0006] Furthermore, a pressure regulating valve is installed at the inlet of the fluorination reactor.

[0007] The utility model has the following beneficial effects: after adopting the above technical scheme, the utility model uses nitrogen to supplement the pressure of the fluorination regeneration system. When the pressure of the fluorination reactor shows a slight positive pressure, the circulating fan is started, and then the electric heater is turned on to heat the fluorination reactor. When the temperature of the fluorination reactor reaches the target value, hydrogen fluoride is added to the system for fluorination. The method and device adopted in this way can reduce the consumption of hydrogen fluoride and nitrogen through a circulation mode, maintain the normal use of energy, and the circulation of the mixed gas can shorten the time of fluorination regeneration. The utility model adopts a circulating fan to sweep hydrogen fluoride and nitrogen, which greatly improves the efficiency of the circulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the embodiments of the utility model patent or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model patent. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 It is a structural schematic diagram of the utility model. DETAILED DESCRIPTION

[0010] The preferred embodiments of the present utility model patent are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present utility model patent can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present utility model patent.

[0011] exist Figure 1 The utility model discloses a fluorination device for tetrafluoroethane catalyst, which comprises a nitrogen heater 1, an electric heater 2 and a fluorination reactor 4, the outlet of a nitrogen gas storage tank 5 is connected to one end of a delivery pipe Ⅰ7 through a switch valve Ⅰ6, the other end of the delivery pipe Ⅰ7 is connected to the inlet of the nitrogen heater 1, the outlet of the nitrogen heater 1 is connected to one end of a delivery pipe Ⅱ8, the outlet of a hydrogen fluoride gas storage tank 9 is connected to a switch valve Ⅱ10 and one end of a delivery pipe Ⅲ11 in sequence, the other end of the delivery pipe Ⅱ8 is combined with the other end of the delivery pipe Ⅲ11 to form a mixing pipeline 12 is connected to the inlet of the fluorination reactor 4, the outlet of the DPA polyurethane catalyst storage tank 13 is connected to the inlet of the fluorination reactor 4 through the switch valve III 14 and the delivery pipe IV 15 in turn, the outlet of the fluorination reactor 4 is connected to the mixing pipe 12 through the delivery pipe 16 to form a circulation branch, the electric heating element 17 of the electric heater 2 is installed on the fluorination reactor 4 and can heat the fluorination reactor, the circulation branch 3 of this embodiment is installed with a circulation fan 18, and the inlet of the fluorination reactor 4 of this embodiment is installed with a pressure regulating valve 19.

[0012] The use process of the utility model is as follows: first, open the switch valve Ⅰ6 of the nitrogen gas storage tank 5, put the nitrogen into the nitrogen heater 1 for initial heating, heat the nitrogen to 300°C, discharge the heated nitrogen into the fluorination reactor 4 through the mixing pipeline 12, pressurize the fluorination reactor 4, make the pressure in the fluorination reactor 4 become a slightly positive pressure state, and control the flow rate of nitrogen addition to 30-50m 3 / h, the flow rate of nitrogen added in this embodiment is controlled at 30m 3 / h, start the circulating fan 18, and then start the electric heater 2 to heat the fluorination reactor 4. The heating rate of the fluorination reactor 4 is 20-30°C / h. The heating rate of the fluorination reactor 4 in this embodiment is 20°C / h. When the temperature of the fluorination reactor 4 reaches 300-330°C, the circulating fan 18 works normally, open the switch valve II10 of the hydrogen fluoride gas tank 9, and slowly add hydrogen fluoride to the fluorination reactor 4. The flow rate of slowly adding hydrogen fluoride is controlled at 5-15 kg / h. In this embodiment, the flow rate of slowly adding hydrogen fluoride is controlled at 10 kg / h. Then, the DPA polyurethane catalyst storage tank 13 is opened, and the DPA polyurethane catalyst is discharged into the fluorination reactor 4. Fluorination reduction is performed by adding nitrogen and hydrogen fluoride. During the fluorination reduction reaction, continuous heating is performed by the electric heater 2 to ensure the normal fluorination reaction. At the same time, nitrogen needs to be supplemented during the fluorination reaction, and the pressure is adjusted by the pressure regulating valve 19 to maintain the pressure in a slightly positive pressure state. The nitrogen and hydrogen fluoride in the fluorination reactor 4 are drawn into the mixing pipeline 12 under the action of the circulating fan 18, and are discharged into the fluorination reactor 4 through the mixing pipeline 12 for recycling.

[0013] Without limitation to this, any changes or substitutions that are not conceived through creative work should be included in the protection scope of this utility model patent. Therefore, the protection scope of this utility model patent should be based on the protection scope defined in the claims.

Claims

1. A fluorination device for tetrafluoroethane catalyst, characterized in that It comprises a nitrogen heater (1), an electric heater (2) and a fluorination reactor (4); the outlet of a nitrogen storage tank (5) is connected to one end of a delivery pipe I (7) via a switch valve I (6); the other end of the delivery pipe I (7) is connected to the inlet of the nitrogen heater (1); the outlet of the nitrogen heater (1) is connected to one end of a delivery pipe II (8); the outlet of a hydrogen fluoride storage tank (9) is connected to a switch valve II (10) and one end of a delivery pipe III (11) in sequence; the other end of the delivery pipe II (8) is connected to the inlet of the delivery pipe III (11); The other end is combined into a mixing pipeline (12) which is connected to the inlet of the fluorination reactor (4); the outlet of the DPA polyurethane catalyst storage tank (13) is connected to the inlet of the fluorination reactor (4) via a switch valve III (14) and a delivery pipe IV (15) in sequence; the outlet of the fluorination reactor (4) is connected to the mixing pipeline (12) via a delivery pipe (16) to form a circulation branch (3); the electric heating element (17) of the electric heater (2) is installed on the fluorination reactor (4) and is capable of heating the fluorination reactor.

2. The fluorination device for tetrafluoroethane catalyst according to claim 1, characterized in that A circulation fan (18) is installed on the circulation branch (3).

3. The fluorination device for tetrafluoroethane catalyst according to claim 1, characterized in that A pressure regulating valve (19) is installed at the inlet of the fluorination reactor (4).

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