Low GWP composition containing trifluoroacetyl fluoride and use thereof

Abstract

The present invention belongs to the field of refrigerant technology, applies trifluoroacetyl fluoride to the field of refrigerants for the first time, and provides a low GWP value composition containing trifluoroacetyl fluoride and a refrigerant containing the composition, wherein the composition comprises trifluoroacetyl fluoride and component A, and component A is selected from the general formula C n F x H y At least one of the following: trifluoroacetyl fluoride content ≥ 50 wt%, wherein n = 1, 2, or 3, y ≥ 1, and x + y = 2n or 2n + 2. The refrigerant may also contain a functional additive to optimize refrigerant performance. The composition of the present invention has low toxicity, high thermal stability, and a global warming potential (GWP) of ≤ 150, meeting international environmental protection requirements. It can operate in a temperature range as low as -85°C. When used in the -40 to -83°C temperature range, the refrigeration system can still maintain positive pressure operation. It is expected to serve as a key component of a new generation of refrigerants to promote further development of the refrigeration industry.

Description

Technical Field

[0001] The present invention belongs to the field of fine chemicals and refrigerants, and particularly relates to a low GWP value composition containing trifluoroacetyl fluoride and use thereof. Background Art

[0002] As global climate change becomes increasingly prominent, more and more countries are pursuing a vision of a carbon-free future. Effective January 1, 2022, the European Union has banned refrigerants containing hydrofluorocarbons (HFCs) with a global warming potential (GWP) of 150 or higher in household or commercial refrigerators and freezers, commercial packaged centralized refrigeration systems rated at 40kW or higher, and mobile room air conditioners. This list of banned refrigerants will continue to expand. Currently, R410A, a mixture of difluoromethane (R32) and pentafluoroethane (R125) with an evaporating temperature between -40°C and -50°C, is a common refrigerant. While non-flammable and exhibiting excellent performance, it has a high GWP of 1924 and will eventually be replaced.

[0003] In the prior art, patent document CN102639668A (application number CN201180004783.5) discloses that a mixed refrigerant of R32 and 2,3,3,3-tetrafluoropropylene (R1234yf) can be used effectively as a replacement for R410A. However, 2,3,3,3-tetrafluoropropylene itself has a high boiling point of -29°C and still has a certain GWP value, which limits its use in low temperature ranges. Patent document CN102925108A (CN201210393640.4) discloses a ternary refrigerant mixed with trifluoroiodomethane, 1,1-difluoroethane (R152a), and propane, which can be used to replace difluorochloromethane (R22) and R410A. However, because trifluoroiodomethane has a boiling point of only -22°C, is inherently unstable, has a low flash point, and is toxic, it is not a safe and environmentally friendly refrigerant substitute. Propane is a flammable and explosive medium. The application prospects of this ternary refrigerant are not good. Currently, the environmentally friendly refrigerants disclosed have many components and complex compositions. The boiling points of commonly used refrigerants at normal pressure are often between -25 and -52°C and -75 and -85°C, and the GWP values ​​are generally over 150. In order to reduce the GWP value of the refrigerant, some refrigerant compositions even use a mixture of ternary or more substances. However, as the number of components of the refrigerant increases, the temperature offset will become larger during the refrigeration process due to the different leakage rates of various materials. Therefore, the development of refrigerants with lower GWP, stability, safety, and normal pressure boiling point covering the medium and low temperature range (-50 to -75°C) is still an urgent problem that the refrigeration industry needs to solve. Summary of the Invention

[0004] In response to the problems existing in the prior art, such as generally high GWP and insufficient types of refrigerants with boiling points in the medium and low temperature range at normal pressure, the present invention provides a low GWP composition containing trifluoroacetyl fluoride, applications of the composition, and a refrigerant containing the composition.

[0005] Explanation of terms:

[0006] Evaporation temperature: The temperature at which the refrigerant evaporates and boils in the evaporator. This temperature is related to the terminal demand and the heat exchange area of ​​the heat exchanger. It is generally selected as the highest phase change temperature required for the refrigerant to boil under the theoretical maximum heat exchange efficiency.

[0007] Evaporation pressure: The maximum pressure at which the refrigerant changes from liquid to gaseous phase at the evaporation temperature.

[0008] Discharge pressure: The pressure at which the refrigerant leaves the chiller outlet condenser in liquid form.

[0009] Refrigeration capacity per unit volume: The cooling capacity generated by a unit volume of refrigerant flowing through a refrigeration system. This is often expressed as the ratio of the total cooling capacity to the refrigerant compressor inlet volume. Refrigeration capacity per unit volume is directly related to the refrigerant type and varies with actual operating conditions.

[0010] ODP: Ozone Depletion Potential (Ozone Decay Index), used to assess the potential impact of a substance's gaseous release into the atmosphere on ozone depletion. The ozone depletion impact of the refrigerant trichlorofluoromethane (R11) is used as a benchmark, with the ODP value of R11 set at 1. The ODPs of other substances are relative to R11.

[0011] GWP: Global Warming Potential, is an index based on the radiative properties of well-mixed greenhouse gases. It is used to measure the radiative forcing of a given well-mixed greenhouse gas per unit mass in the current atmosphere relative to carbon dioxide, integrated over a selected time.

[0012] COP (Coefficient of Performance) refers to the amount of cooling capacity achieved per unit of power consumption and is an important technical and economic indicator of a refrigeration system (refrigerator). A high COP indicates a high energy efficiency of the refrigeration system (refrigerator).

[0013] R152a: 1,1-difluoroethane, chemical formula C2H4F2, boiling point at atmospheric pressure -25°C, critical temperature 113°C, flash point -79°C, flammable and explosive, with an explosion limit of 3.7-18%. Its ODP is 0 and GWP is 138. When used as a refrigerant, the system requires special explosion-proof treatment and is often compounded with non-flammable refrigerants.

[0014] R1270: Propylene, with the chemical formula C3H6, has a boiling point of -47.7°C at atmospheric pressure, a critical temperature of 91.9°C, and a flash point of -108°C. It is flammable and explosive, with an explosion limit of 2.4% to 10.3%. Its ODP is 0 and its GWP is 1.8. When used as a refrigerant, the system requires special explosion-proof treatment. Due to the presence of double bonds, it is inherently unstable and tends to self-aggregate.

[0015] R32: Difluoromethane, chemical formula CH2F2, has a normal boiling point of -51.6°C and a critical temperature of 78.4°C. It is non-flammable. Its ODP is 0 and its GWP is 677. It is commonly used in refrigerant blends and is currently being replaced.

[0016] R170: Ethane, chemical formula C2H6, atmospheric boiling point -88.6°C, critical temperature 32.2°C, flash point -129.5°C, flammable and explosive, with an explosion limit of 3-16%. Its ODP is 0 and GWP is 20. When used as a refrigerant, the system requires special explosion-proof treatment and is rarely used commercially.

[0017] R125: Pentafluoroethane, chemical formula CF3CHF2, atmospheric boiling point -48.45°C, critical temperature 66°C, non-flammable. Its ODP is 0 and GWP is 3170. It is commonly used in compounding and is currently being replaced.

[0018] R410A: This refrigerant is a mixture of 50wt% R32 (difluoromethane) and 50wt% R125 (pentafluoroethane). It has a normal boiling point of -51.6°C and a critical temperature of 72.5°C. Its ODP is 0 and its GWP is 1920. It is currently being replaced.

[0019] R23: Trifluoromethane, chemical formula CHF3, has a normal boiling point of -84°C and a critical temperature of 25.7°C. It is non-flammable. Its ODP is 0 and its GWP is 12400. It is commonly used in low-temperature refrigeration and is currently being replaced.

[0020] Trifluoroacetyl fluoride: Its molecular formula is C2F4O. It is a gas at room temperature and pressure. It is commonly used to synthesize fluorine-containing fine chemicals or fluorine-containing polymer monomers. It is also commonly used as an etching gas for silicon-based material processing.

[0021] Trifluoroacetyl fluoride has the following properties: boiling point at normal pressure is -59°C, critical temperature is 49.9°C; it is non-flammable; the GWP value is 0; trifluoroacetyl fluoride itself has strong thermal stability, and experiments have shown that it does not undergo thermal decomposition at a high temperature of 200°C; it is non-corrosive; trifluoroacetyl fluoride easily decomposes into hydrogen fluoride and trifluoroacetic acid when in contact with water.

[0022] Specifically, in order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0023] The present invention provides application of trifluoroacetyl fluoride in the field of refrigerants.

[0024] Trifluoroacetyl fluoride is used as a refrigerant in refrigeration systems with a temperature range of -40 to -83°C. Although trifluoroacetyl fluoride hydrolyzes into hydrogen fluoride and trifluoroacetic acid when exposed to water, the water content of all materials used in the system must be strictly controlled by displacement. Therefore, trifluoroacetyl fluoride can meet the requirements for long-term stable use in refrigeration systems. Although pentafluoropropionyl fluoride and carbonyl fluoride have similar structures and chemical properties to trifluoroacetyl fluoride, pentafluoropropionyl fluoride has a temperature range of around -30°C, which allows for other existing refrigerants with better performance. However, carbonyl fluoride is not suitable for use as a refrigerant due to the highly toxic decomposition products.

[0025] In a refrigeration system, the evaporation temperature is defined as the temperature of the gas when the fluid vaporizes. The evaporation temperature is proportional to the pressure of the environment and varies with the pressure. The evaporation temperature is usually measured at a standard atmospheric pressure. The atmospheric evaporation temperature of a refrigerant often determines the temperature range in which it is used. The closer the operating temperature is to its atmospheric evaporation temperature, the higher the COP value that the refrigeration system can achieve. Commonly used refrigerants often have atmospheric boiling points between -25 to -52°C and -75 to -85°C, while trifluoroacetyl fluoride has an atmospheric boiling point of -59°C, which can fill the blank boiling point range of existing refrigerant systems. When trifluoroacetyl fluoride is used as an active ingredient in a refrigerant, it can reduce the GWP of the refrigerant composition, making the GWP of the refrigerant composition ≤150, thereby meeting relevant international requirements for carbon emission reduction.

[0026] The present invention also provides a low GWP value composition containing trifluoroacetyl fluoride, characterized in that the composition comprises trifluoroacetyl fluoride and component A, and the component A is selected from the group consisting of: n F x H y trifluoroacetyl fluoride content ≥ 50wt%, wherein n = 1, 2 or 3, y ≥ 1, x + y = 2n or 2n + 2.

[0027] Preferably, the component A is selected from the group consisting of n F x H y One of the following, wherein n=1, 2 or 3, y≥1, and x+y=2n or 2n+2.

[0028] More preferably, the component A is selected from any one of R32 (difluoromethane), R125 (pentafluoroethane), R1270 (propylene), R170 (ethane) and R152a (difluoroethane).

[0029] Preferably, the content of trifluoroacetyl fluoride in the composition is 50 to 99 wt %, and more preferably, the content of trifluoroacetyl fluoride in the composition is 78 to 99 wt %.

[0030] Preferably, the boiling point of the composition at atmospheric pressure is -40 to -85°C; further preferably, the boiling point of the composition at atmospheric pressure is -40 to -83°C; further preferably, the boiling point of the composition at atmospheric pressure is -55 to -59°C.

[0031] The present invention also provides application of the composition in refrigerants.

[0032] The present invention also provides a refrigerant containing the above composition, characterized in that the refrigerant has an evaporation temperature of -40 to -85°C, a GWP value of not higher than 150, an ODP of 0, an exhaust pressure of 1300 to 3400 kPa, and a COP value of 0.8 to 2.

[0033] Preferably, the refrigerant has an evaporation temperature of -40 to -83°C, a GWP value of 0.3 to 150, and a COP value of 0.85 to 1.92.

[0034] More preferably, the evaporation temperature of the refrigerant is -55 to -59°C, and the COP value is 1.2 to 1.44.

[0035] Preferably, the refrigerant further includes a functional auxiliary agent, and the functional auxiliary agent is selected from at least one of a corrosion inhibitor, a stabilizer, a lubricant, an indicator, and a fluorescent leak detector.

[0036] More preferably, the functional additive does not contain silicon.

[0037] The trifluoroacetyl fluoride in the refrigerant provided by the invention has good compatibility with commonly used corrosion inhibitors, stabilizers, lubricants, indicators and fluorescent leak detection agents, and has good circulation performance and higher stability.

[0038] For example, trifluoroacetyl fluoride works well with common stabilizers such as oxetane and isoprene, and has good compatibility with perfluoropolyester and perfluoropolyether lubricants. However, its decomposition is accelerated when used with silicon-containing compounds, and it is incompatible with water.

[0039] Preferably, the content of the functional additive in the refrigerant is 0.01 to 3 wt %. In the present invention, the functional additive has no effect on the refrigeration efficiency, refrigeration temperature range, greenhouse gas effect value and other properties of the refrigerant.

[0040] The one or more technical solutions provided by the present invention have at least the following technical effects:

[0041] 1. The composition and refrigerant provided by the present invention contain trifluoroacetyl fluoride, which can reduce the GWP value of the refrigerant and meet international environmental protection requirements.

[0042] 2. Trifluoroacetyl fluoride, an effective component of the refrigerant provided by the present invention, has good compatibility with commonly used corrosion inhibitors, stabilizers, lubricants, indicators, and fluorescent leak detection agents.

[0043] 3. The composition and refrigerant of the present invention have a lower operating temperature range, which can cover a refrigeration temperature range as low as -85°C, while filling the gap in the refrigeration temperature range of existing refrigerants; when used in the temperature range of -40 to -83°C, the refrigeration system can still ensure positive pressure operation, and the COP value can reach 2.

[0044] 4. The composition of the present invention has low cost and low toxicity. When used as a refrigerant, the trifluoroacetyl fluoride gas volatilized is much less toxic than SO2 and NH3. When used in combination with other refrigerant active ingredients, its cost is much lower than that of fourth-generation refrigerants represented by R1234yf. DETAILED DESCRIPTION

[0045] The composition and refrigerant containing trifluoroacetyl fluoride are further described below by way of specific examples.

[0046] All embodiments and comparative examples use two-stage compression refrigeration. The critical temperature of R23 refrigerant is 25.9°C, and the critical temperature of R170 is 32.2°C. Circulating water cooling is not suitable for both. Therefore, in the embodiments and comparative examples containing R23 and R170, 7°C water was used to condense the refrigerant to 20°C before testing. The remaining embodiments and tests of existing refrigerants were all conducted using circulating water condensed to 32°C before testing. The present invention is further described below with reference to the following examples, but the scope of protection of the present invention is not limited thereto. Any adjustments made to the technical solution of the present invention by professionals in this field should fall within the scope of protection of the present invention.

[0047] The cooling capacity per unit volume is a characteristic of the refrigerant itself. Comparing and analyzing the embodiments and comparative examples with similar evaporating temperatures and evaporating pressures is helpful in finding a refrigerant with more advantageous performance.

[0048] Example 1

[0049] A low-GWP composition containing trifluoroacetyl fluoride is prepared by physically mixing trifluoroacetyl fluoride and R152a at room temperature. This composition is then mixed with the lubricant perfluoro-2,5-dimethyl-3,6-dioxanonane to produce a refrigerant. The lubricant content in the refrigeration cycle is 3 wt%. The main components and properties of the refrigerant are shown in Table 1. Compared with Comparative Example 1, Example 1 shows an increased COP and a decreased GWP, indicating that the refrigerant is more energy-efficient, low-carbon, and environmentally friendly under these operating conditions.

[0050] Example 2

[0051] A low-GWP composition containing trifluoroacetyl fluoride is obtained by physically mixing trifluoroacetyl fluoride and R152a at room temperature. The components and properties of the refrigerant produced from this composition are shown in Table 1. Compared with Comparative Example 2, Example 2 exhibits an increased COP, a decreased GWP, and very similar refrigeration capacity per unit volume. Compared with Comparative Example 3, Example 2 exhibits an increased COP, a decreased GWP, and an increased refrigeration capacity per unit volume. This is primarily due to the superior refrigeration capacity per unit volume of trifluoroacetyl fluoride itself compared to R125.

[0052] Example 3

[0053] A low-GWP composition containing trifluoroacetyl fluoride is obtained by physically mixing trifluoroacetyl fluoride and R1270 at room temperature. The components and properties of the refrigerant prepared from this composition are shown in Table 1. Currently, there is no refrigerant in the prior art with an atmospheric evaporation temperature of -57°C that can be compared with Example 3.

[0054] Example 4

[0055] A low-GWP composition containing trifluoroacetyl fluoride is obtained by physically mixing trifluoroacetyl fluoride and R32 at room temperature. The components and properties of the refrigerant prepared from this composition are shown in Table 1. Currently, there is no refrigerant in the prior art with an atmospheric evaporation temperature of -57°C that can be compared with Example 4.

[0056] Example 5

[0057] A low GWP composition containing trifluoroacetyl fluoride is obtained by physically mixing trifluoroacetyl fluoride and R32 at room temperature. The components and properties of the refrigerant prepared from the composition are shown in Table 1. Compared with Comparative Example 4, Example 5 has an increased COP value and a significantly reduced GWP value. The reason for the higher unit volumetric refrigeration capacity in Comparative Example 4 is that the atmospheric boiling point of R23 is -82°C, and its evaporation temperature at atmospheric pressure should be around -82°C. When used as a refrigerant, if the evaporation temperature rises to -59°C, the same as in Example 5, the evaporation pressure also needs to be increased to 308 kPa. At this time, the evaporation pressure is greater than atmospheric pressure, which is not conducive to the normal use of R23 under this working condition. The high unit volumetric refrigeration capacity is caused by the excessively high compressor inlet pressure, not when R23 is used under atmospheric pressure. Compared with Example 5, the unit volumetric refrigeration capacity is also higher as shown in Comparative Example 4.

[0058] Example 6

[0059] A low-GWP composition containing trifluoroacetyl fluoride is obtained by physically mixing trifluoroacetyl fluoride and R170 at room temperature. The components and properties of the refrigerant produced from this composition are shown in Table 1. Compared with Comparative Example 5, Example 6 shows an increased COP and a decreased GWP, indicating that the refrigerant is more energy-efficient under these operating conditions. Compared with Comparative Example 6, Example 6 shows an increased COP, a decreased GWP, and an increased refrigeration capacity per unit volume. This is primarily due to the superior refrigeration capacity per unit volume of trifluoroacetyl fluoride itself compared to R23.

[0060] Comparative Example 1-Comparative Example 6

[0061] They are the existing refrigerants, and the refrigerants and their properties are shown in Table 1.

[0062] Table 1. Composition and properties of refrigerants in Examples and Comparative Examples

[0063]

[0064]

[0065] In summary, since trifluoroacetyl fluoride itself is low in toxicity and non-corrosive, and its boiling point at atmospheric pressure is -59°C, which is in the blank area of ​​the atmospheric boiling point of existing refrigerants, it can fill the gap in the medium and low temperature range of refrigerant operating temperature under atmospheric pressure; and its GWP is 0, it can be compounded with existing refrigerants, and the GWP of the resulting composition is lower than 150, while maintaining a relatively high unit volume cooling capacity and COP value, and is expected to play an important role in the refrigeration field as a new generation of refrigerant.

Claims

1. A low GWP composition containing trifluoroacetyl fluoride, characterized in that: The composition comprises trifluoroacetyl fluoride and component A, wherein the component A is selected from any one of R32, R125, R1270, R170 and R152a; and the content of the trifluoroacetyl fluoride is greater than or equal to 50 wt %.

2. The low GWP composition containing trifluoroacetyl fluoride according to claim 1, characterized in that The content of trifluoroacetyl fluoride is 50~99wt%.

3. The low GWP composition containing trifluoroacetyl fluoride according to any one of claims 1 to 2, characterized in that The boiling point of the composition at normal pressure is -40 to -85°C.

4. Use of the low GWP composition containing trifluoroacetyl fluoride according to any one of claims 1 to 3 in a refrigerant.

5. A refrigerant comprising the low GWP composition containing trifluoroacetyl fluoride according to any one of claims 1 to 3, characterized in that: The refrigerant has a GWP value of no more than 150, an ODP of 0, a COP value of 0.8 to 2, and an evaporation temperature of -40 to -85°C.

6. The refrigerant containing a low GWP composition of trifluoroacetyl fluoride according to claim 5, characterized in that: The evaporation temperature of the refrigerant is -40~-83°C.

7. The refrigerant containing a low GWP composition of trifluoroacetyl fluoride according to claim 5, characterized in that: The invention also includes a functional auxiliary agent, which is selected from at least one of a corrosion inhibitor, a stabilizer, a lubricant, an indicator, and a fluorescent leak detector.

8. The refrigerant containing a low GWP composition of trifluoroacetyl fluoride according to claim 7, characterized in that: The content of the functional aid in the refrigerant is 0.01-3 wt %.

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