HK1182518A - Heat transfer compositions - Google Patents

Description

Heat transfer composition

The present invention relates to heat transfer compositions and, in particular, to heat transfer compositions that may be suitable as replacements for existing refrigerants, such as R-134a, R-152a, R-1234yf, R-22, R-410A, R-407A, R-407B, R-407C, R507, and R-404 a.

The listing or discussion of a prior-published document or any background in this specification is not necessarily to be taken as an admission that the document or background is part of the state of the art or is common general knowledge.

Mechanical refrigeration systems and related heat transfer devices such as heat pumps and air conditioning systems are well known. In these systems, the refrigerant liquid evaporates at low pressure, taking heat from the surrounding area. The resulting vapor is then compressed and passed to a condenser where it condenses and releases heat to a second zone, the condensate is returned to the evaporator through an expansion valve, completing the cycle. The mechanical energy required for compressing the vapor and pumping the liquid is provided by, for example, an electric motor or an internal combustion engine.

In addition to having a suitable boiling point and high latent heat of vaporization, preferred properties of the refrigerant include low toxicity, non-flammability, non-corrosiveness, high stability, and lack of objectionable odor. Other desirable properties are ease of compression at pressures below 25 bar, low discharge temperature at compression, high refrigeration capacity, high efficiency (high coefficient of performance), and evaporator pressures in excess of 1 bar at the desired evaporation temperature.

Dichlorodifluoromethane (refrigerant R-12) has a suitable combination of properties and is the most widely used refrigerant for many years. As it is internationally noted that fully and partially halogenated chlorofluorocarbons are damaging the earth's protective ozone layer, a consensus has been reached that their manufacture and use should be severely limited and eventually phased out completely. In the 90 s of the 20 th century, the use of dichlorodifluoromethane was phased out.

Chlorodifluoromethane (R-22) was introduced as a replacement for R-12 due to its lower ozone depletion potential. Later on it was noted that R-22 is a potent greenhouse gas, so its use was also gradually stopped.

Although the heat transfer devices of the type to which the present invention relates are substantially closed systems, loss of refrigerant to the atmosphere can occur due to leaks during the operation of the device or during maintenance procedures. Therefore, it is very important to replace fully and partially halogenated chlorofluorocarbon refrigerants with materials that have zero ozone depletion potential.

In addition to the possibility of ozone depletion, it has been proposed that significant concentrations of halocarbon refrigerants in the atmosphere can contribute to global warming (the so-called greenhouse effect). It is therefore desirable to use refrigerants that have relatively short atmospheric lifetimes, either by being able to react with other atmospheric components (e.g., hydroxyl radicals) or because they are readily decomposed by photolytic processes.

R-410A and R-407 refrigerants (including R-407A, R-407B and R-407C) have been introduced as alternative refrigerants to R-22. However, R-22, R-410A, and R-407 refrigerants all have high global warming potentials (GWP, also known as greenhouse warming potential).

1, 1, 1, 2-tetrafluoroethane (refrigerant R-134a) was introduced as a substitute refrigerant for R-12. R-134a is an energy efficient refrigerant currently used in automotive air conditioning. But it is relative to CO₂Has a GWP of 1430 (by definition CO)₂A GWP of 1) is a greenhouse gas. The proportion of the overall environmental impact of automotive air conditioning systems using such gases, which can be attributed to direct discharge of refrigerant, is typically in the range of 10-20%. The european union has passed laws to exclude refrigerants with GWP greater than 150 from being used in new vehicle models since 2011. The automotive industry is affecting the global technology platform and has a global impact on greenhouse gas emissions anyway, and there is a need to obtain fluids with reduced environmental impact (e.g. reduced GWP) compared to HFC-134 a.

R-152a (1, 1-difluoroethane) has been identified as a replacement for R-134 a. It is somewhat more efficient than R-134a and has a greenhouse warming potential of 120. However, the flammability of, for example, R-152a is considered too high for safe use in automotive air conditioning systems. It is particularly believed that its lower flammability limit in air is too low, its flame speed is too high and its ignition energy is too low.

Accordingly, there is a need to provide alternative refrigerants with improved properties (e.g., low flammability). Fluorocarbon combustion chemistry is complex and unpredictable. Blending non-flammable fluorocarbons with flammable fluorocarbons does not always reduce the flammability of the fluid or reduce the range of flammable compositions in the air. For example, the inventors have found that if non-flammable R-134a is mixed with flammable R-152a, the lower flammability limit of the mixture changes in an unpredictable manner. If ternary or quaternary compositions are considered, this becomes even more complex and hardly predictable.

It would also be desirable to provide alternative refrigerants that can be used in existing plants (e.g., refrigeration plants) with little or no modification.

R-1234yf (2, 3, 3, 3-tetrafluoropropene) has been identified as a candidate replacement refrigerant to replace R-134a in certain applications, particularly in automotive air conditioning or heat pump applications. Its GWP is about 4. R-1234yf is flammable, but its flammability characteristics are generally considered acceptable for some applications, including automotive air conditioning or heat pumps. In particular, when compared to R-152a, its lower flammability limit is higher than R-152a, its minimum ignition energy is higher than R-152a and its flame speed in air is significantly lower than R-152 a.

In terms of greenhouse gas emissions, it is believed that the environmental impact of operating an air conditioning or refrigeration system should be referenced not only to the so-called "direct" GWP of the refrigerant, but also to the so-called "indirect" emissions, i.e. those of carbon dioxide resulting from the electrical energy or fuel consumption of the operating system. Several metrics of this overall GWP Impact have been developed, including those known as Total equivalent warming effect (TEWI) analysis or Life-Cycle carbon production (LCCP) analysis. Both of these measurements include evaluating the impact of refrigerant GWP and energy efficiency on overall warming impact. Carbon dioxide emissions associated with manufacturing refrigerants and system equipment should also be considered.

R-1234yf has been found to have significantly lower energy efficiency and refrigeration capacity than R-134a and, in addition, it has been found that the fluid exhibits increased pressure drop in the system piping and heat exchangers. As a result, to use R-1234yf and obtain energy efficiency and cooling performance comparable to that of R-134a requires increased complexity of the plant and increased size of the piping, thereby causing increased indirect emissions associated with the plant. In addition, the production of R-1234yf is believed to be more complex and less efficient in its use of starting materials (fluorination and chlorination) than R-134 a. Long-term pricing for R-1234yf is currently predicted to be 10-20 times that of R-134 a. This price difference and the need for additional hardware expense will limit the rate at which the changing refrigerant and thus the overall environmental impact of the refrigeration or air conditioning can be reduced. In summary, replacing R-134a with R-1234yf will consume more raw material than R-134a and result in more indirect emissions of greenhouse gases.

Some prior art designs for R-134a have not even been able to accept the reduced flammability of some heat transfer compositions (any composition having a GWP of less than 150 is considered somewhat flammable).

It is therefore a primary object of the present invention to provide a heat transfer composition which itself may be suitably or suitably employed as a replacement for existing refrigeration applications, which heat transfer composition should have a reduced GWP and should also have a deviation from the values of capacity and energy efficiency (which may suitably be expressed as a "coefficient of performance") such as those obtained using existing refrigerants (e.g. R-134a, R-152a, R-1234yf, R-22, R-410A, R-407A, R-407B, R-407C, R507 and R-404a) of ideally within 10%, preferably within less than 10% (e.g. about 5%) of these values. It is known in the art that such magnitude differences between fluids are often addressed by redesigning the features of the device and system operation. The composition should also desirably have reduced toxicity and acceptable flammability.

The present invention addresses the above deficiencies by providing a heat transfer composition comprising (i) a first component selected from the group consisting of trans-1, 3, 3, 3-tetrafluoropropene (R-1234ze (e)), cis-1, 3, 3, 3-tetrafluoropropene (R-1234ze (z)), and mixtures thereof; (ii) (ii) carbon dioxide (CO2 or R-744) and (iii) a third component selected from the group consisting of 2, 3, 3, 3-tetrafluoropropene (R-1234yf), 3, 3, 3-trifluoropropene (R-1243zf), and mixtures thereof.

All chemicals described herein are commercially available. For example, fluorochemicals are available from Apollo Scientific (UK).

Typically, the compositions of the present invention comprise trans-1, 3, 3, 3-tetrafluoropropene (R-1234ze (E)). Most of the specific compositions described herein comprise R-1234ze (E). It will, of course, be understood that some or all of R-1234ze (E) in these compositions may be replaced by R-1234ze (Z). However, the trans isomer is currently preferred.

Typically, the compositions of the present invention comprise at least about 5% by weight of R-1234ze (E), preferably at least about 15% by weight. In one embodiment, the compositions of the present invention comprise at least about 45% by weight of R-1234ze (e), for example from about 50% to about 98% by weight.

The choice of components and preferred amounts for use in the present invention are determined by a combination of the following properties:

(a) flammability: non-flammable or non-flammable compositions are preferred.

(b) The effective operating temperature of the refrigerant in the evaporator of the air conditioning system.

(c) The temperature "glide" of the mixture and its effect on the heat exchanger performance.

(d) Critical temperature of the composition. It should be above the maximum expected condenser temperature.

The need to avoid ice formation on the air side surface of the refrigerant evaporator limits the effective operating temperature in air conditioning cycles, particularly motor vehicle air conditioning. Generally, an air conditioning system must cool and dry humid air; liquid water will form on the air side surface. Most evaporators (and even automotive applications) have a fin surface with narrow fin spacing. If the evaporator is too cold, ice may form between the fins, thereby restricting airflow over the surface and reducing overall performance by reducing the working area of the heat exchanger.

For automotive air Conditioning applications (Modern reflection and air Conditioning, 1988 edition, chapter 27, by AD Althouse et al, which is incorporated herein by reference), it is known that refrigerant evaporation temperatures of-2 ℃ or higher are preferred to thereby ensure that the problem of ice formation is avoided.

Non-azeotropic refrigerant mixtures are also known to exhibit a temperature "glide" of evaporation or condensation. In other words, as the refrigerant gradually evaporates or condenses at a constant pressure, the temperature of the (evaporation) increases or the temperature of the (condensation) decreases, and the total temperature difference (inlet to outlet) is referred to as temperature glide. The effect of slip on evaporation or condensation temperature must also be considered.

The critical temperature of the heat transfer composition should be above the maximum expected condenser temperature. This is because the cycle efficiency decreases as the critical temperature approaches. When this occurs, the latent heat of the refrigerant is reduced, so more heat rejection occurs in the condenser due to cooling of the gaseous refrigerant; this requires a larger area per unit of heat transfer.

R-410A is commonly used in building and household heat pump systems, for example, having a critical temperature of about 71 ℃ higher than the maximum normal condensation temperature required to deliver about 50 ℃ of available warm air. Automotive loads require air at about 50 c, so if the temperature of a conventional vapor compression cycle is utilized, the critical temperature of the fluid of the present invention should be above this temperature. The critical temperature is preferably at least 15K higher than the maximum air temperature.

In one aspect, the critical temperature of the compositions of the present invention is greater than about 65 ℃, preferably greater than about 70 ℃.

The carbon dioxide content of the compositions of the present invention is limited primarily by considerations (b) and/or (c) and/or (d) above. Suitably, the compositions of the present invention typically comprise up to about 35% by weight of R-744, preferably up to about 30% by weight.

In a preferred aspect, the compositions of the present invention comprise from about 4% to about 30% by weight, preferably from about 4% to about 28% by weight of R-744, alternatively from about 8% to about 30% by weight, alternatively from about 10% to about 30% by weight.

The level of the third component (which may include a flammable refrigerant such as R-1234yf) is selected such that the lower flammability limit of the residual fluorocarbon mixture at room temperature (e.g., 23 ℃) in air (as determined in ASHRAE-34 in a 12 liter flask test instrument) is greater than 5% v/v, preferably greater than 6% v/v, even in the absence of the carbon dioxide component of the composition, most preferably such that the mixture is non-flammable. The flammability problem is discussed further later in this specification.

Typically, the compositions of the present invention comprise up to about 60% by weight of the third component. Preferably, the composition of the present invention comprises up to about 50% by weight of the third component. Suitably, the composition of the present invention comprises up to about 45% by weight of the third component. In one aspect, the present compositions comprise from about 1% to about 40% by weight of the third component.

In one embodiment, the present compositions comprise from about 10 to about 95% by weight of R-1234ze (E), from about 2 to about 30% by weight of R-744, and from about 3 to about 60% by weight of the third component.

In the compositions herein (including the claims), all% amounts referred to herein are by weight based on the total weight of the composition, unless otherwise specified.

For the avoidance of doubt, it is to be understood that in the compositions of the invention described herein, the upper and lower values specified for a range of amounts of a component may be interchanged in any way provided that the resulting range falls within the broadest scope of the invention.

In one embodiment, the inventive composition consists essentially of (or consists of) a first component (e.g., R-1234ze (E)), R-744, and a third component.

The term "consisting essentially of means that the compositions of the present invention comprise substantially no other components, in particular no other (hydrogenated) (fluoro) compounds (e.g. (hydrogenated) (fluoro) alkanes or (hydrogenated) (fluoro) alkenes) known for use in heat transfer compositions. We include the term "consisting of within the meaning of" consisting essentially of.

For the avoidance of doubt, any of the compositions of the invention described herein (including those of a particular identified compound and amount of a compound or component) may consist essentially of (or consist of) the identified compound or component in those compositions.

The third component is selected from the group consisting of R-1234yf, R-1243zf, and mixtures thereof.

In one aspect, the third component comprises only one of the listed components. For example, the third component contains only one of R-1234yf or R-1243 zf. Thus, the present compositions may be a ternary mixture of one of the listed third components (e.g. R-1234yf or R-1243zf), R-1234ze (E) and R-744.

However, mixtures of R-1234yf and R-1243zf may be used as the third component.

The present invention contemplates compositions wherein the third component comprises additional compounds. Examples of these compounds include difluoromethane (R-32), 1, 1-difluoroethane (R-152a), fluoroethane (R-161), 1, 1, 1, 2-trifluoroethane (R-134a), 1, 1, 1-trifluoroethane (R-263fb), 1, 1, 1, 2, 3-pentafluoropropane (R-245eb), propylene (R-1270), propane (R-290), n-butane (R-600), isobutane (R-600a), ammonia (R-717), and mixtures thereof.

For example, the compositions of the present invention may comprise R-134 a. R-134a, if present, is typically present in an amount of about 2% to about 50% by weight, such as about 5% to about 40% by weight (e.g., about 5% to about 20% by weight).

Preferably, the compositions of the present invention comprising R-134a are non-flammable at a test temperature of 60 ℃ using the ASHRAE 34 method. Advantageously, mixtures of vapors present in equilibrium with the compositions of the present invention at any temperature from about-20 ℃ to 60 ℃ are also non-flammable.

In one embodiment, the third component comprises R-1234 yf. The third component may consist essentially of (or consist of) R-1234 yf.

Compositions of the invention comprising R-1234yf typically comprise it in an amount of from about 2% to about 60% by weight, for example from about 4% to about 50% by weight. Suitably, R-1234yf is present in an amount of from about 6% to about 40%.

Preferred compositions of the present invention comprise from about 10% to about 92% R-1234ze (E), from about 4% to about 30% by weight R-744, and from about 4% to about 60% by weight R-1234 yf. For example, such compositions may comprise from about 22% to about 84% R-1234ze (E), from about 10% to about 28% by weight R-744, and from about 6% to about 50% by weight R-1234 yf.

More preferred compositions of the invention comprise from about 14 to about 86% R-1234ze (E), from about 4 to about 26% by weight R-744, and from about 10 to about 60% by weight R-1234 yf.

Another group of compositions of the present invention comprising R-1234yf comprises from about 32% to about 88% of R-1234ze (E), from about 8% to about 28% by weight of R-744, and from about 4% to about 40% by weight of R-1234 yf.

In one embodiment, the third component comprises R-1243 zf. The third component may consist essentially of (or consist of) R-1243 zf.

The compositions of the present invention comprising R-1243zf typically comprise them in an amount of from about 2% to about 60% by weight, for example from about 4% to about 50% by weight. Suitably, R-1243zf is present in an amount of from about 6% to about 40%.

Preferred compositions of the present invention comprise from about 20% to about 92% R-1234ze (E), from about 4% to about 30% by weight R-744, and from about 4% to about 50% by weight R-1243 zf. For example, such compositions may comprise from about 32% to about 88% R-1234ze (E), from about 6% to about 28% by weight R-744, and from about 6% to about 40% by weight R-1243 zf.

More advantageous compositions of the invention comprise from about 25% to about 91% R-1234ze (E), from about 4% to about 30% by weight R-744, and from about 5% to about 45% by weight R-1243 zf. For example, such compositions may comprise from about 27% to about 85% by weight of R-1234ze (E), from about 10% to about 28% by weight of R-744, and from about 5% to about 45% by weight of R-1243 zf.

The compositions of the present invention may also comprise pentafluoroethane (R-125). R-125, if present, is typically present in an amount of up to about 40% by weight, preferably from about 2% to about 20% by weight.

The compositions of the present invention suitably comprise substantially no R-1225 (pentafluoropropene), suitably substantially no R-1225ye (1, 2, 3, 3, 3-pentafluoropropene) or R-1225zc (1, 1, 3, 3, 3-pentafluoropropene), which compounds may have associated toxicity problems.

By "substantially free" is meant that the composition of the present invention comprises 0.5% or less by weight of said components, preferably 0.1% or less, based on the total weight of the composition.

Certain compositions of the present invention may be substantially free of:

(i)2, 3, 3, 3-tetrafluoropropene (R-1234yf),

(ii) cis-1, 3, 3, 3-tetrafluoropropene (R-1234ze (Z)), and/or

(iii)3, 3, 3-trifluoropropene (R-1243 zf).

The compositions of the present invention have zero ozone depletion potential.

Generally, the GWP of the compositions of the invention is less than 1300, preferably less than 1000, more preferably less than 800, 500, 400, 300 or 200, especially less than 150 or 100, and in some cases even less than 50. Unless otherwise stated, the GWP value of IPCC (international panel on Climate Change, united nations inter-government Climate Change committee) TAR (Third Assessment Report) is used herein.

Advantageously, the flammability risk of the composition is reduced when compared to the third component alone (e.g., R-1234yf or R-1243 zf). Preferably, the composition has a reduced flammability risk when compared to R-1234 yf.

In one aspect, the composition has, in comparison to a third component (e.g., R-1234yf or R-1243 zf): (a) a higher lower flammability limit, (b) a higher ignition energy, or (c) a lower flame speed. In a preferred embodiment, the composition of the invention is non-combustible. Advantageously, mixtures of vapors present in equilibrium with the compositions of the present invention at any temperature from about-20 ℃ to 60 ℃ are also non-flammable.

Flammability may be determined according to ASHRAE standard 34 in conjunction with ASTM standard E-681, using the test method according to annex page 34 of 2004, the entire contents of which are incorporated herein by reference.

In some applications, it may not be necessary to classify the formulation as non-flammable according to the ASHRAE-34 method; fluids with sufficiently reduced flammability limits in air can be developed to make them safe to use, for example, if a refrigeration unit charge is leaked into the surrounding environment, it is virtually impossible to produce a flammable mixture.

R-1234ze (E) is non-flammable at 23 ℃ in air, but exhibits flammability in humid air at higher temperatures. It has been determined by experimentation that if the "fluorine ratio" Rf of a mixture of R-1234ze (e) and a flammable fluorocarbon (e.g., R-32, R-152a or R-161), defined as Rf in terms of moles of total refrigerant mixture, is greater than about 0.57, the mixture remains non-flammable at 23 ℃ in air:

rf ═ g (g of fluorine)/(g of fluorine + g of hydrogen)

Thus, for R-161, R_f1/(1+5) ═ 1/6(0.167) and is flammable. In contrast, R of R-1234ze (E)_f4/6(0.667) and is non-flammable. We have found by experiment that 20% v/v mixtures of R-161 in R-1234ze (E) are likewise non-flammable. The non-flammable mixture has a fluorine ratio of 0.2 ANGSTROM (1/6) +0.8 ANGSTROM (4/6) ═ 0.567.

The effectiveness of this relationship between flammability and fluorine ratio of 0.57 or higher has heretofore been experimentally demonstrated for HFC-32, HFC-152a and mixtures of HFC-32 and HFC-152 a.

For example, Takizawa et al, Reaction Stoichimetry for Combustion of fluoroethane Blends, ASHRAE Transactions 112(2)2006 (which is incorporated herein by reference) show that there is an approximately linear relationship between this ratio and the flame speed for mixtures containing R-152a, with increasing fluorine ratios resulting in lower flame speeds. The data in this citation teaches that the fluorine ratio needs to be greater than about 0.65 to bring the flame speed down to zero, i.e., to render the mixture non-flammable.

Similarly, Minor et al (Du Pont patent application WO2007/053697) provide teachings on the flammability of many hydrofluoroolefins, indicating that if the fluorine ratio is greater than about 0.7, such compounds can be expected to be non-flammable.

In accordance with this prior art teaching, it is unexpected that if the fluorine ratio Rf of a mixture of R-1234ze (E) and a flammable fluorocarbon (e.g., R-1234yf or R-1243zf) is greater than about 0.57, the mixture will remain nonflammable in air at 23 ℃.

Furthermore, we have determined that if the fluorine ratio is greater than about 0.46, it may be desirable for the lower flammability limit of the composition to be greater than 6% v/v in air at room temperature.

The amount of the third component in this composition is increased especially by preparing a low or non-flammable R-744/third component/R-1234 ze (e) mixture containing an unexpectedly small amount of R-1234ze (e). It is believed that the heat transfer composition exhibits increased cooling capacity and/or reduced pressure drop as compared to the same composition comprising higher amounts (e.g., nearly 100%) of R-1234ze (e).

Thus, the compositions of the present invention exhibit a completely unexpected combination of low/non-flammability, low GWP, and improved refrigeration performance characteristics. Some refrigeration performance characteristics are explained in more detail below.

Temperature glide is a characteristic of a refrigerant that can be considered as the difference between the bubble point temperature and the dew point temperature of a zeotropic mixture at constant pressure. If it is desired to replace the fluid with a mixture, it is often preferred to slip a similar or reduced replacement fluid. In one embodiment, the compositions of the present invention are non-azeotropic.

Advantageously, the composition of the invention has a volumetric refrigeration capacity of at least 85%, preferably at least 90% or even at least 95% of the existing refrigerant fluid it replaces.

The volumetric refrigeration capacity of the compositions of the invention is typically at least 90% of the R-1234 yf. Preferably, the compositions of the present invention have a volumetric refrigeration capacity of at least 95% of R-1234yf, such as from about 95% to about 120% of R-1234 yf.

In one embodiment, the cycle efficiency (coefficient of performance, COP) of the composition of the invention is within about 5% or even better than the existing refrigerant fluid being replaced.

Suitably, the composition of the invention has a compressor discharge temperature within about 15K, preferably within about 10K or even within about 5K of the existing refrigerant fluid it replaces.

Preferably, the compositions of the present invention have an energy efficiency of at least 95% (preferably at least 98%) of R-134a under comparable conditions, with reduced or equal pressure drop characteristics and a cooling capacity of 95% or more of the R-134a value. Advantageously, the composition has higher energy efficiency and lower pressure drop characteristics than R-134a under equivalent conditions. Advantageously, the composition also has better energy efficiency and pressure drop characteristics than R-1234yf alone.

The heat transfer compositions of the present invention are suitable for use in existing device designs and are compatible with all types of lubricants used with HFC refrigerants in use today. They may optionally be stabilized with mineral oil or compatible therewith by using suitable additives.

Preferably, the compositions of the present invention are combined with a lubricant when used in a heat transfer device.

Suitably, the lubricant is selected from: mineral oil, silicone oil, polyalkyl benzenes (PABs), polyol esters (POEs), polyalkylene glycols (PAGs), polyalkylene glycol esters (PAG esters), polyvinyl ethers (PVEs), poly (alpha-olefins), and combinations thereof.

Advantageously, the lubricant further comprises a stabilizer.

Preferably, the stabilizer is selected from the group consisting of diene-based compounds, phosphates, phenol compounds and epoxides and mixtures thereof.

Suitably, the composition of the present invention may be combined with a flame retardant.

Advantageously, the flame retardant is selected from the group consisting of tris- (2-chloroethyl) -phosphate, (chloropropyl) phosphate, tris- (2, 3-dibromopropyl) -phosphate, tris- (1, 3-dichloropropyl) -phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, fluorinated iodocarbons, fluorinated bromohydrocarbons, trifluoroiodomethane, perfluoroalkanes, bromo-fluoroalkyl amines, and mixtures thereof.

Preferably, the heat transfer composition is a refrigerant composition.

In one embodiment, the present invention provides a heat transfer device comprising a composition of the present invention.

Preferably, the heat transfer device is a refrigeration device.

Suitably, the heat transfer means is selected from: automotive air conditioning systems, domestic air conditioning systems, commercial air conditioning systems, domestic refrigerator systems, domestic freezer systems, commercial refrigerator systems, commercial freezer systems, chiller air conditioning systems, chiller refrigeration systems, and commercial or domestic heat pump systems. Preferably, the heat transfer device is a refrigeration device or an air conditioning system.

The compositions of the present invention are particularly useful in automotive air conditioning applications, such as automotive air conditioning systems (e.g., the heat pump cycle of automotive air conditioning).

Advantageously, the heat transfer device comprises a compressor of the centrifugal type.

The present invention also provides the use of the composition of the present invention in a heat transfer device as described herein.

According to yet another aspect of the present invention, there is provided a blowing agent comprising the composition of the present invention.

According to another aspect of the invention, there is provided a foamable composition comprising one or more components capable of forming foam and the composition of the invention.

Preferably, the one or more components capable of forming a foam are selected from: polyurethanes, thermoplastic polymers and resins such as polystyrene and epoxy resins.

According to yet another aspect of the present invention, there is provided a foam obtainable from the foamable composition of the present invention.

Preferably, the foam comprises the composition of the present invention.

According to another aspect of the present invention there is provided a sprayable composition comprising a material to be sprayed and a propellant comprising a composition of the present invention.

According to yet another aspect of the present invention, there is provided a method for cooling an article comprising condensing a composition of the present invention and then evaporating said composition in the vicinity of the article to be cooled.

According to another aspect of the present invention, there is provided a method for heating an article, comprising condensing a composition of the present invention in the vicinity of the article to be heated and then evaporating said composition.

According to yet another aspect of the present invention, there is provided a method for extracting a substance from biomass comprising contacting the biomass with a solvent comprising a composition of the present invention, and separating the substance from the solvent.

According to another aspect of the present invention, there is provided a method of cleaning an article comprising contacting the article with a solvent comprising a composition of the present invention.

According to a further aspect of the present invention there is provided a method for extracting a material from an aqueous solution comprising contacting the aqueous solution with a solvent comprising a composition of the present invention and separating the material from the solvent.

According to another aspect of the present invention, there is provided a method for extracting a material from a particulate solid substrate, comprising contacting the particulate solid substrate with a solvent comprising a composition of the present invention, and separating the material from the solvent.

According to yet another aspect of the present invention, there is provided a mechanical power generation device comprising the composition of the present invention.

Preferably, the mechanical power generation device is adapted to use a rankine cycle or a variation thereof to generate work from the heat.

According to another aspect of the present invention, there is provided a method of retrofitting a heat transfer device comprising the steps of removing an existing heat transfer fluid and introducing a composition of the present invention. Preferably, the heat transfer device is a refrigeration device or a (static) air conditioning system. Advantageously, the method further comprises the step of obtaining a quota of emissions for dosing greenhouse gases (e.g. carbon dioxide).

In accordance with the above-described modification, the existing heat transfer fluid can be completely removed from the heat transfer device prior to introduction of the composition of the present invention. The existing heat transfer fluid may also be partially removed from the heat transfer device and subsequently introduced into the composition of the present invention.

In another embodiment, where the existing heat transfer fluid is R-134a, the compositions of the present invention comprise R-134a, R-1234ze (E), R-744, the third component and any R-125 present (and optional components such as lubricants, stabilizers or additional flame retardants), R-1234ze (E) and R-744, etc. may be added to R-134a in the heat transfer unit, thereby forming the compositions of the present invention and the heat transfer unit of the present invention in situ. Some of the existing R-134a may be removed from the heat transfer apparatus prior to addition of R-1234ze (E), R-744, etc., to assist in providing the components of the composition of the present invention in the desired proportions.

Accordingly, the present invention provides a process for the preparation of the composition and/or heat transfer device of the present invention which comprises introducing R-1234ze (E), R-744, the third component and any R-125 required, and optional components such as lubricants, stabilisers or additional flame retardants, into a heat transfer device containing an existing heat transfer fluid (R-134 a). Optionally, at least a portion of R-134a is removed from the heat transfer apparatus prior to introduction of R-1234ze (E), R-744, etc.

Of course, the compositions of the present invention may also be prepared simply by mixing R-1234ze (E), R-744, the third component and any R-125 desired (and optional components such as lubricants, stabilizers or additional flame retardants) in the desired proportions. The composition may then be added to a heat transfer device (or used in any other manner as defined herein) that does not contain R-134a or any other existing heat transfer fluid, such as a device from which R-134a or any other existing heat transfer fluid has been removed.

In yet another aspect of the invention, a method for reducing environmental impact due to handling of a product (comprising an existing compound or composition) is provided, the method comprising at least partially replacing the existing compound or composition with a composition of the invention. Preferably, the method comprises the step of obtaining an emission quota of the rationed greenhouse gas.

The environmental impact includes the production and emission of greenhouse warming gases by the operation of the product.

As noted above, this environmental impact may be considered to include not only those emissions from a leak or other loss of a compound or composition having a significant environmental impact, but also carbon dioxide emissions caused by the energy consumed by the device over its operating life. This environmental impact can be quantified by a metric known as total equivalent warming effect (TEWI). This measurement has been used to quantify the environmental impact of certain stationary refrigeration and air conditioning apparatus, including, for example, supermarket refrigeration systems (see, e.g., for examplehttp://en.wikipedia.org/wiki/Total equivalent warming impact)。

Environmental effects are also believed to include greenhouse gas emissions resulting from the synthesis and manufacture of the compound or composition. In this case, the emissions produced are taken into account in the energy consumption and direct depletion effect to obtain what is known as life cycle carbon production (LCCP, see for examplehttp://www.sae.org/ events/aars/presentations/2007papasavva.pdf) The measurement of (2). LCCP is often used to evaluate the environmental impact of automotive air conditioning systems.

The emission allowance is obtained by reducing emissions of pollutants that contribute to global warming and may be, for example, stored, traded, or sold. They are conventionally expressed in carbon dioxide equivalents. Thus, if emissions of 1kg of R-134a are avoided, 1 × 1300 to 1300kg of CO can be obtained₂An equivalent emission allowance.

In another embodiment of the present invention, there is provided a method for generating greenhouse gas emission credits comprising (i) replacing an existing compound or composition with a composition of the present invention, wherein the composition of the present invention has a GWP that is lower than the existing compound or composition; and (ii) obtaining greenhouse gas emission credits for the replacement step.

In a preferred embodiment, the use of the composition of the present invention results in a device with a lower overall equivalent warming effect and/or lower life cycle carbon production than devices obtained using existing compounds or compositions.

These methods can be carried out on any suitable product, for example in the fields of air conditioning, refrigeration (e.g., low and medium temperature refrigeration), heat transfer, foaming agents, aerosols or sprayable propellants, gaseous dielectrics, freezing technology, veterinary procedures, dental procedures, fire suppression, flame suppression, solvents (e.g., carriers for flavors and fragrances), cleaning agents, air horns, pellet guns, local anesthetics, and expansion applications. Preferably, the field is air conditioning or refrigeration.

Examples of suitable products include heat transfer devices, blowing agents, foamable compositions, sprayable compositions, solvents, and mechanical power generation devices. In a preferred embodiment, the product is a heat transfer device, such as a refrigeration device or an air conditioning unit.

The environmental impact of the existing compound or composition, as measured by GWP and/or TEWI and/or LCCP, is higher than that of the composition of the invention replacing it. The existing compound or composition may comprise a fluorocarbon, such as a perfluoro-, hydro fluoro-, chlorofluoro-or hydrochlorofluorocarbon compound or it may comprise a fluorinated olefin.

Preferably, the existing compound or composition is a heat transfer compound or composition, such as a refrigerant. Examples of refrigerants that may be replaced include R-134A, R-152a, R-1234yf, R-410A, R-407A, R-407B, R-407C, R507, R-22, and R-404A. The compositions of the invention are particularly suitable as replacements for R-134a, R-152a or R-1234yf, especially R-134a or R-1234 yf.

Any amount of an existing compound or composition may be substituted to reduce the environmental impact. This may depend on the environmental impact of the existing compound or composition being replaced and the environmental impact of the replacement composition of the invention. Preferably, the existing compound or composition in the product is completely replaced by the composition of the invention.

The invention is illustrated by the following non-limiting examples.

Examples

Flammability of

The flammability of the R1243zf mixture in R-1234ze (E) was found to be significantly reduced experimentally using ASHRAE Standard 34 test method appendix B compared to the flammability of pure R-1243zf or R-1234 yf.

In particular, it was found that if the molar ratio of R1243 zf: R-1234ze (E) is less than about 14: 86 (corresponding to a mass ratio of 12: 88), then the mixture of R1243zf in R-1234ze (E) is non-flammable at 23 ℃ in air at 50% relative humidity.

Furthermore, it was found that mixtures containing higher amounts of R1243zf had a lower flammability limit of greater than 6% v/v if the molar ratio of R1243 zf: R-1234ze (E) was less than about 1. The lower flammability limit of R1234yf determined in the same test equipment was-6%, so binary mixtures of R1243 zf: R-1234ze (E) with a molar ratio zf: ze of less than about 1: 1 showed improved lower flammability limits compared to pure R1234 yf.

The flammability of a mixture of R1234yf with R-1234ze (E) in air at 50% relative humidity at 23 ℃ was studied in a 12 litre flask set-up according to the method described in ASHRAE Standard 34, appendix B. It was found that if the proportion of R-1234ze (E) in a binary mixture of R1234yf and R-1234ze (E) is greater than about 16% by volume, the mixture is non-flammable.

A preferred group of ternary compositions of R744/R1234yf/R-1234ze (E) are therefore those in which the ratio of R-1234ze (E) to R1234ze (1234 yf) is greater than about 16: 84 by volume, as these are still non-flammable.

Modeling performance data

Generation of accurate physical property models

The physical properties of R1234yf and R-1234ze (E), namely the critical point, vapor pressure, liquid and vapor enthalpies, liquid and vapor densities, and vapor and liquid heat capacities, required to simulate the performance of a refrigeration cycle are determined experimentally with precision at a pressure range of 0-200 bar and a temperature range of-40 ℃ to 200 ℃, and the resulting data is used to generate the Helmholtz free energy equation of a Span-Wagner type state model for fluids in NIST REFPER version 8.0 software, which is guided by the user's guidelineswww.nist.gov/srd/PDFfiles/REFPROP8.PDFAre more fully described herein and incorporated by reference. The ideal gas enthalpy for the two fluids was estimated as a function of temperature using the molecular simulation software, hyperchemim version 7.5 (which is incorporated herein by reference) and the resulting ideal gas enthalpy function was used for regression of the equation of state for these fluids. The predicted values of the model for R1234yf and R-1234ze (E) were compared to those obtained using the standard file for R1234yf and R-1234ze (E) contained in REFPROP version 9.0, which is incorporated herein by reference. It was found that a good anastomosis was obtained for the performance of each fluid.

The vapor-liquid equilibrium behavior of R-1234ze (E) was studied in a series of binary pairs with carbon dioxide, R-32, R-125, R-134a, R-152a, R-161, propane and propylene over a temperature range of-40 ℃ to +60 ℃ that covers the practical operating range of most refrigeration and air-conditioning systems. The composition was varied across the composition space for each binary pair in the experimental procedure, the mixed parameters for each binary pair were regressed to the experimentally obtained data and the parameters were also introduced into the REFPROP software model. The academic literature was then searched for data on the gas-liquid equilibrium behavior of carbon dioxide with hydrofluorocarbons R-32, R-125, R-152a, R-161 and R-152 a. The VLE data obtained from the sources cited in the paper of Akasaka of the simple multi-fluid model to the coatings of the vapour-liquid equivalent of the real mixtures of carbon dioxide, Journal of Thermal Science and Technology, 159-168, 4, 1, 2009 (which is incorporated herein by reference) were then used to generate mixing parameters for the relevant binary mixtures, which were then also introduced into the REFPRPROP software model. Standard REFPROP mixing parameters of carbon dioxide with propane and propylene were also introduced into the model.

The resulting software model was used to compare the performance of selected inventive fluids with R-134a in heat pump cycle applications.

Heat pump cycle comparison

In a first comparison, the behavior of the fluid is evaluated at low winter ambient temperatures using conditions typical of automotive heat pump load operation for a simple vapor compression cycle. In this comparison, the pressure drop effect was included in the model by assigning a representative expected pressure drop to the reference fluid (R-134a) and then estimating the equivalent pressure drop of the mixed refrigerant of the present invention at the same heat capacity in the same unit. The reference fluid (R-134a) and the mixed fluid of the present invention were compared on the basis of equal heat exchange area. The method used to derive this model is to derive a so-called UA model for the refrigerant condensation, evaporation, supercooling of refrigerant liquid, and superheating of refrigerant vapor for the same effective overall heat transfer coefficient assumption for this process. The derivation of such models for zeotropic refrigerant mixtures in Heat pump cycles is explained more fully in chapter iii of the reference R Radermacher & Y Hwang, vaporpompression Heat Pumps with regenerative mixtures (pub Taylor & Francis2005), which is incorporated herein by reference.

In short, the model starts from initial estimates of the condensation and evaporation pressures of the refrigerant mixture and estimates the respective temperatures at which the condensation process in the condenser and the evaporation process in the evaporator start and end. These temperatures are then used in conjunction with the specified changes in air temperature across the condenser and evaporator to estimate the total heat exchange area required for each of the condenser and evaporator. This estimation is an iterative calculation: the condensing and evaporating pressures are adjusted to ensure that the total heat exchange area is the same for the reference fluid and for the mixed refrigerant.

For this comparison, the worst case scenario for a heat pump in an automotive application is assumed to have the following assumptions for air temperature and for R-134a cycle conditions.

Circulation conditions

The model assumes that each heat exchanger is counter-current in its calculation of the effective temperature difference for each heat exchange process.

The condensation and evaporation temperatures of the composition were adjusted to give a heat exchange area usage comparable to that of the reference fluid. The following input parameters were used.

Using the above model, performance data for the reference R-134a is shown below.

The performance data generated for selected compositions of the invention are set forth in the following table. These tables show key parameters of the heat pump cycle, including working pressure, volumetric heat capacity, energy efficiency (expressed as coefficient of performance COP for heating), compressor discharge temperature, and pressure drop in the piping system. Volumetric heat capacity of a refrigerant is a measure of the amount of heating available for a given size of compressor operating at a fixed speed. Coefficient of performance (COP) is the ratio of the amount of thermal energy delivered in the condenser of a heat pump cycle to the amount of work consumed by the compressor.

The performance of R-134a was taken as a reference point for comparison of heat capacity, energy efficiency and pressure drop. This fluid was used as a reference to compare the ability of the fluid of the present invention to be used in the heat pump mode of an automotive composite air conditioning and heat pump system.

It should be noted that the utility of the fluid of the present invention is not limited to automotive systems. In practice, these fluids can be used in so-called stationary (domestic or commercial) installations. Currently, the predominant fluids used in such fixtures are R-410A (with a GWP of 2100) or R22 (with a GWP of 1800 and an ozone depletion potential of 0.05). The use of the fluids of the present invention in such fixtures provides the ability to achieve similar utility but using fluids that do not have ozone depletion potential and that have significantly reduced GWP compared to R410A.

It is apparent that the fluids of the present invention can provide improved energy efficiency over R-134a or R-410A. It has been unexpectedly found that the addition of carbon dioxide to the refrigerant of the present invention can increase the COP of the resulting cycle above that of R-134a, even where the mixing of the other mixture components would result in a fluid less energy efficient than R-134 a.

It has also been found that for all fluids of the present invention, up to about 30% w/w CO can be used₂The composition of (a), which produces a refrigerant fluid having a critical temperature of about 70 ℃ or greater. This is especially important for stationary heat pump applications where R-410A is currently used. The basic thermodynamic efficiency of a vapor compression process is affected by the proximity of the critical temperature to the condensing temperature. R-410A has gained acceptance and is considered an acceptable fluid for this application; the critical temperature is 71 ℃. It has been unexpectedly found that significant amounts of CO can be introduced into the fluids of the present invention₂(critical temperature 31 ℃) to produce a mixture with a similar or higher critical temperature than R-410A. Preferred compositions of the present invention therefore have a critical temperature of about 70 ℃ or greaterAnd (4) degree.

The heat capacity of the preferred fluids of the present invention generally exceeds the heat capacity of R134 a. It is believed that R-134a alone, operating in a motor vehicle air conditioning and heat pump system, cannot provide all of the potential through air heating requirements in the heat pump mode. Therefore, a higher heat capacity than R-134a is preferred for potential use in automotive air conditioning and heat pump applications. The fluid of the present invention provides the ability to optimize fluid capacity and energy efficiency for both air conditioning and cooling modes to provide improved overall energy efficiency for both load operating conditions.

For reference, under the same cycling conditions, the heat capacity of R-410A was estimated to be about 290% of the R-134a value, corresponding to an energy efficiency found to be about 106% of the reference R-134a value.

From an inspection of these tables, it is apparent that the fluids of the present invention have been found to have a heat capacity and energy efficiency comparable to that of R-410A, thereby allowing the modification of existing R-410A technology to use the fluids of the present invention, if so desired.

Some other benefits of the fluids of the present invention are described in more detail below.

The compositions of the present invention provide a reduced pressure drop over R-134a at comparable cooling capacities. This reduced pressure drop characteristic is believed to lead to further improvements in energy efficiency (through a reduction in pressure loss) in practical systems. Pressure drop effects are particularly important for automotive air conditioning and heat pump applications, and therefore these fluids provide particular benefits for this application.

Combining the Properties of the inventive fluid with CO₂A binary mixture of/R1234 ze (E) was compared. For removing CO₂All ternary compositions of the invention, other than/R1234 yf/R1234ze (E), the energy efficiency of the ternary mixture with respect to having equal CO₂The binary mixture of contents increases. Thus, at least for CO₂In the case of a content of less than 30% w/w, these mixtures being relative to CO₂Improved solution of/R1234 ze (E) binary refrigerant mixture.

It is possible to produce CO with an energy efficiency comparable to or slightly higher than that of R-134a₂Mixtures of/R1234 yf/R1234ze (E). It is therefore unexpected that such ternary fluid systems of the present invention provide a means of ameliorating the inherent energy inefficiency of R1234 yf.

The performance of the selected ternary R-744/R-1243zf/R-1234ze (e) mixture of the present invention was also simulated using the previously discussed heat pump cycle. The results are tabulated as attached. It was found that the addition of R-1243zf to R-1234ze (E) improved the specific pressure drop and volume of the mixture for any given amount of mixed R-744. It was also found that the critical temperature of the ternary mixture was increased compared to a binary R-744/R-1234ze (E) mixture of equal volume amounts. For example, in a dual mode (air conditioning/heat pump) system operating as an air conditioner in a hot ambient atmosphere, increased critical temperatures are important to improve performance.

Consistent with an optimal R-744 content, for a given level of R-1243zf in the mixture, the energy efficiency (COP) of the mixture exhibits a maximum. The resulting COP maximum was also observed to increase with increasing R-1243zf levels.

Briefly, the present invention provides novel compositions that exhibit an unexpected combination of advantageous properties, including good refrigeration performance, low flammability, low GWP, and/or miscibility with lubricants, as compared to existing refrigerants, such as R-134a and the proposed refrigerant R-1234 yf.

The invention is defined by the following claims.

Claims (64)

1. A heat transfer composition comprising:

(i) a first component selected from the group consisting of trans-1, 3, 3, 3-tetrafluoropropene (R-1234ze (E)), cis-1, 3, 3, 3-tetrafluoropropene (R-1234ze (Z)), and mixtures thereof;

(ii) carbon dioxide (R-744); and

(iii) a third component selected from the group consisting of 2, 3, 3, 3-tetrafluoropropene (R-1234yf), 3, 3, 3-trifluoropropene (R-1243zf), and mixtures thereof.

2. A composition according to claim 1, wherein said first component comprises R-1234ze (e).

3. A composition according to claim 1 or 2, comprising at least about 15% by weight R-1234ze (e).

4. The composition of any of the preceding claims comprising up to about 35% by weight of R-744, preferably up to about 30% by weight of R-744.

5. The composition of claim 4 comprising from about 4% to about 30% by weight of R-744, preferably from about 4% to about 28% by weight, alternatively from about 8% to about 30% by weight, alternatively from about 10% to about 30% by weight.

6. The composition according to any one of the preceding claims, comprising up to about 60% by weight of the third component, preferably up to about 50% by weight.

7. A composition according to any preceding claim comprising from about 10 to about 95% by weight R-1234ze (E), from about 2 to about 30% by weight R-744, and from about 3 to about 60% by weight of the third component.

8. The composition according to any of the preceding claims, having a critical temperature of greater than about 65 ℃, preferably greater than about 70 ℃.

9. The composition according to any one of claims 1 to 8, wherein the third component comprises R-1234yf, preferably from about 4% to about 60% by weight of R-1234 yf.

10. A composition according to claim 9, comprising from about 10 to about 92% by weight R-1234ze (e), from about 4 to about 30% by weight R-744, and from about 4 to about 60% by weight R-1234 yf.

11. A composition according to claim 10, comprising from about 22 to about 84% by weight R-1234ze (e), from about 10 to about 28% by weight R-744, and from about 6 to about 50% by weight R-1234 yf.

12. A composition according to claim 10, comprising from about 14 to about 86% R-1234ze (e), from about 4 to about 26% by weight R-744, and from about 10 to about 60% by weight R-1234yf, or from about 32 to about 88% R-1234ze (e), from about 8 to about 28% by weight R-744, and from about 4 to about 40% by weight R-1234 yf.

13. The composition according to any one of claims 1 to 8, wherein the third component comprises R-1243zf, preferably about 4% to about 60% by weight of R-1243 zf.

14. A composition according to claim 13, comprising from about 20 to about 92% R-1234ze (e), from about 4 to about 30% by weight R-744, and from about 4 to about 50% by weight R-1243 zf.

15. A composition according to claim 14, comprising from about 32 to about 88% R-1234ze (e), from about 6 to about 28% by weight R-744, and from about 6 to about 40% by weight R-1243 zf.

16. A composition according to any preceding claim, consisting essentially of R-1234ze (E), R-744, and the third component.

17. The composition of any one of claims 1 to 15, further comprising pentafluoroethane (R-125).

18. A composition according to any preceding claim, wherein the composition has a GWP of less than 1000, preferably less than 150.

19. A composition according to any preceding claim, wherein the composition has a volumetric refrigeration capacity within about 15%, preferably within about 10%, of the existing refrigerant it is intended to replace.

20. A composition according to any preceding claim, wherein the composition is less flammable than R-1234yf alone or R-1243zf alone.

21. A composition according to claim 50, wherein the composition has, as compared to R-1234yf alone or R-1243zf alone:

(a) a higher flammability limit;

(b) higher ignition energy; and/or

(c) Lower flame speed.

22. The composition according to any of the preceding claims, having a fluorine ratio (F/(F + H)) of from about 0.42 to about 0.7, preferably from about 0.44 to about 0.67.

23. The composition of any one of the preceding claims, which is non-flammable.

24. The composition of any of the preceding claims, wherein the composition has a cycle efficiency within about 5% of the existing refrigerant it is intended to replace.

25. The composition according to any one of the preceding claims, wherein the composition has a compressor discharge temperature within about 15K, preferably within about 10K, of the existing refrigerant it is intended to replace.

26. A composition comprising a lubricant and the composition of any of the preceding claims.

27. The composition of claim 26, wherein the lubricant is selected from the group consisting of: mineral oil, silicone oil, polyalkyl benzenes (PABs), polyol esters (POEs), polyalkylene glycols (PAGs), polyalkylene glycol esters (PAG esters), polyvinyl ethers (PVEs), poly (alpha-olefins), and combinations thereof.

28. The composition of claim 26 or 27, further comprising a stabilizer.

29. The composition of claim 28, wherein the stabilizer is selected from the group consisting of: diene-based compounds, phosphates, phenolic compounds and epoxides and mixtures thereof.

30. A composition comprising a flame retardant and the composition of any of the preceding claims.

31. The composition of claim 30, wherein the flame retardant is selected from the group consisting of: tris- (2-chloroethyl) -phosphate, (chloropropyl) phosphate, tris- (2, 3-dibromopropyl) -phosphate, tris- (1, 3-dichloropropyl) -phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminum trihydrate, polyvinyl chloride, fluorinated iodocarbon, fluorinated bromocarbon, trifluoroiodomethane, perfluoroalkyl amines, bromo-fluoroalkyl amines, and mixtures thereof.

32. The composition of any of the preceding claims, which is a refrigerant composition.

33. A heat transfer device comprising the composition of any one of claims 1 to 32.

34. Use of a composition according to any one of claims 1 to 32 in a heat transfer device.

35. A heat transfer device according to claim 33 or 34 which is a refrigeration device.

36. A heat transfer device according to claim 35 selected from: a motor vehicle air conditioning system, a household air conditioning system, a commercial air conditioning system, a household refrigerator system, a household freezer system, a commercial refrigerator system, a commercial freezer system, a chiller air conditioning system, a chiller refrigeration system, and a commercial or household heat pump system, preferably wherein the heat transfer device is a motor vehicle air conditioning system.

37. A heat transfer device according to claim 35 or 36 comprising a compressor.

38. A blowing agent comprising the composition of any one of claims 1 to 32.

39. A foamable composition comprising one or more components capable of forming foam and the composition of any one of claims 1 to 32, wherein the one or more components capable of forming foam are selected from: polyurethanes, thermoplastic polymers and resins, such as polystyrene and epoxy resins, and mixtures thereof.

40. A foam obtainable from the foamable composition of claim 39.

41. The foam of claim 44 comprising the composition of any one of claims 1 to 32.

42. A sprayable composition comprising a material to be sprayed and a propellant comprising a composition according to any of claims 1 to 32.

43. A method for cooling an article comprising condensing a composition according to any one of claims 1 to 32 and then evaporating the composition in the vicinity of the article to be cooled.

44. A method for heating an article comprising condensing a composition according to any one of claims 1 to 32 in the vicinity of the article to be heated and then evaporating the composition.

45. A process for extracting a substance from biomass comprising contacting biomass with a solvent comprising the composition of any one of claims 1 to 32, and separating the substance from the solvent.

46. A method of cleaning an article comprising contacting the article with a solvent comprising the composition of any one of claims 1 to 32.

47. A method of extracting a material from an aqueous solution comprising contacting the aqueous solution with a solvent comprising the composition of any one of claims 1 to 62, and separating the substance from the solvent.

48. A method for extracting a material from a particulate solid substrate, comprising contacting the particulate solid substrate with a solvent comprising the composition of any one of claims 1 to 32, and separating the material from the solvent.

49. A mechanical power generation device comprising the composition of any one of claims 1 to 32.

50. A mechanical power generation device according to claim 49 adapted to generate work from heat using a Rankine cycle or a variant thereof.

51. A method of retrofitting a heat transfer device comprising the steps of removing an existing heat transfer fluid and introducing the composition of any of claims 1-32.

52. The method of claim 51, wherein the heat transfer device is a refrigeration device.

53. The method of claim 52, wherein the heat transfer device is an air conditioning system.

54. A method for reducing environmental impact due to handling a product comprising an existing compound or composition, the method comprising at least partially replacing the existing compound or composition with a composition according to any one of claims 1 to 32.

55. A process for making a composition according to any one of claims 1 to 32 and/or a heat transfer device according to any one of claims 33 or 35 to 37 comprising R-134a, the process comprising introducing R-1234ze (e), R-744, a third component and optionally R-125, a lubricant, stabiliser and/or a flame retardant into a heat transfer device comprising an existing heat transfer fluid R-134 a.

56. A process according to claim 55, comprising the step of removing at least part of the existing R-134a from the heat transfer apparatus prior to introducing the R-1234ze (E), R-744, the third component and optionally the R-125, the lubricant, the stabiliser and/or the flame retardant.

57. A method for generating greenhouse gas emission credits comprising (i) replacing an existing compound or composition with a composition according to any one of claims 1 to 32, wherein the composition according to any one of claims 1 to 32 has a lower GWP than the existing compound or composition; and (ii) obtaining greenhouse gas emission credits for the replacement step.

58. The method of claim 57, wherein use of the composition of the invention results in a lower overall equivalent warming effect and/or lower life cycle carbon production than results obtained using existing compounds or compositions.

59. The method of claim 57 or 58, carried out on a product from the fields of air conditioning, refrigeration, heat transfer, foaming agents, aerosols or sprayable propellants, gaseous dielectrics, cryosurgery, veterinary procedures, dental procedures, fire extinguishing, flame suppression, solvents, cleaners, air horns, pellet guns, local anesthetics, and expansion applications.

60. The method of claim 54 or 59, wherein the product is selected from the group consisting of: a heat transfer device, a blowing agent, a foamable composition, a sprayable composition, a solvent, or a mechanical power generation device.

61. The method of claim 60, wherein the product is a heat transfer device.

62. The method of any one of claims 52 or 55 to 69, wherein the existing compound or composition is a heat transfer composition.

63. The process of claim 62 wherein the heat transfer composition is a refrigerant selected from the group consisting of R-134a, R-1234yf, R-152a, R-404A, R-410A, R-507, R-407A, R-407B, R-407D, R-407E, and R-407F.

64. Any novel heat transfer composition substantially as hereinbefore described, optionally with reference to the examples.