WO2008009928A2

WO2008009928A2 - Heat transfer compositions

Info

Publication number: WO2008009928A2
Application number: PCT/GB2007/002709
Authority: WO
Inventors: Robert Elliott Low; Stuart Corr
Original assignee: Ineos Fluor Holdings Limited
Priority date: 2006-07-17
Filing date: 2007-07-17
Publication date: 2008-01-24
Also published as: WO2008009928A3; DE202007008291U1

Abstract

A heat transfer composition comprising: (i) R-1225yeE; (ii) R-32, R-161, or R- 152a; and (iii) at least one further refrigerant selected from carbon dioxide (R-744); fluoromethane (R-41); fluoroethane (R-161); 1,1,1-trifluoroethane (R-143a); 1,1,1,2-tetrafluoroethane (R-134a); 1,1,2,2-tetrafluoroethane (R-134); dimethyl ether; heptafluoropropane (R-227ea); propane (R-290); propene (R-1270); isobutane (R-600a); n-butane (R-600) 2,3,3,3-tetrafluoropropene (R-1234yf); 1,1- difluorocyclopropane; 1,1,2-trifluorocyclopropane; 1,1,2,2- tetrafluorocyclopropane; pentafluorocyclopropane, pentafluoroethane (R-125) or ammonia or mixtures thereof.

Description

HEAT TRANSFER COMPOSITIONS

The invention relates to heat transfer compositions, and in particular to heat transfer compositions which may be suitable as replacements for existing refrigerants such as R-134a, R-410A. R-407C, R-404a, R-407A and R-407B and R-507, but especially R-134a and R-407C.

Mechanical refrigeration systems (and related heat transfer devices such as heat pumps and air-conditioning systems) are well known. In such systems, a refrigerant liquid evaporates at low pressure taking heat from the surrounding zone. The resulting vapour is then compressed and passed to a condenser where it condenses and gives off heat to a second zone, the condensate being returned through an expansion valve to the evaporator, so completing the cycle. Mechanical energy required for compressing the vapour 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 a high latent heat of vaporisation, the properties preferred in a refrigerant include low toxicity, non-flammability, non-corrosivity, high stability and freedom from objectionable odour. Other desirable properties are ready compressibility at pressures below 25 bars, low discharge temperature on compression, high refrigeration capacity, high efficiency (high coefficient of performance) and an evaporator pressure in excess of 1 bar at the desired evaporation temperature.

Dichlorodifluoromethane (refrigerant R- 12) possesses a suitable combination of properties and was for many years the most widely used refrigerant. Due to international concern that fully and partially halogenated chlorofluorocarbons, such as dichlorodifluoromethane and chlorodifluoromethane, were damaging the earth's protective ozone layer, there was general agreement that their manufacture and use should be severely restricted and eventually phased out completely. The use of dichlorodifluoromethane was phased out in the 1990's. 1,1,1,2-tetrafluoro ethane (refrigerant R-134a) was introduced as a replacement refrigerant for R-12. However, despite having a low ozone depletion potential, R- 134a has a global warming potential (GWP) of 1300.

Whilst heat transfer devices of the type to which the present invention relates are essentially closed systems, loss of refrigerant to the atmosphere can occur due to leakage during operation of the equipment or during maintenance procedures. It is important, therefore, to replace fully and partially halogenated chlorofluorocarbon refrigerants by materials having zero ozone depletion potentials.

In addition to the possibility of ozone depletion, it has been suggested that significant concentrations of halocarbon refrigerants in the atmosphere might contribute to global warming (the so-called greenhouse effect). It is desirable, therefore, to use refrigerants which have relatively short atmospheric lifetimes as a result of their ability to react with other atmospheric constituents such as hydroxyl radicals or as a result of ready degradation through photolytic processes.

There is a need to provide alternative refrigerants having improved properties, such as low flammability. There is also a need to provide alternative refrigerants that may be used in existing devices such as refrigeration devices with little or no modification.

US 2004/0127383 (US-B2-6858571) (Honeywell International, Inc.) describes the use of pentafluoropropene (R-1225), especially R-1225ye, in combination with R- 1243zf, R-152a and R-1234ze.

US 2004/0119047 and US 2004/0256594 (Honeywell International, Inc.) discloses heat transfer compositions comprising a fluoroalkene of formula XCF₂ R_3-2, where x is a C₂ or C₃ unsaturated, substituted or unsubstituted alkyl radical, R is Cl, F₅ Br, I or H and z is 1 to 3, the compositions having a reduced global warming potential (GWP).

US-A-7098176 B and US 2006/0022166 (Honeywell International, Inc.) disclose azeotrope-like compositions comprising effective amounts of R-1234yf and R- 1225yeZ.

WO 2006/094303 (DuPont) discloses compositions which may be heat transfer compositions comprising R-1225ye and a further refrigerant. Specifically disclosed compositions include inter alia combinations of R-1225ye and R-32; R- 1225ye and R-134a; R-1225ye, R-134a and R-32; R-1225ye, R-1234yf, R-32 and R-134a; and azeotropic or near azeotropic compositions comprising 1% to 99% R- 1225ye and 99% to 1% R- 134a.

R-1225ye (also known as HFC-1225ye) is 1,2,3,3,3-pentafluoropropene (CF₃- CF=CHF). It can exist as two stereoisomers Z and E, which are known to have very similar boiling points. Our reference to R-1225ye encompasses both isomers, and also mixtures thereof. In some embodiments, preferably the isomers are present in a mass ratio of Z to E such that at last 50% of the R-1225ye exists as the E isomer, even more preferably at least 80%.

R-1225ye is non-flammable and has low Greenhouse Warming Potential (relative to CO₂). Its boiling point is ca. -18°C (for the isomeric mixture) and its critical temperature is estimated to be 113⁰C. These properties compares closely to that of R-134a (1,1,1,2-tetrafluoroethane) which has boiling point -26.4°C, a critical temperature of 101°C, and GWP of 1300. R-1225ye is therefore a potential alternative to R- 134a.

However, the properties of this fluid alone render it not suitable as a direct replacement for R-134a. In particular, its capacity is too low, by which is meant that a refrigerator or air conditioning system having a fixed compressor displacement and designed for R-134a will deliver less cooling when charged with R-1225ye and controlled to the same operating temperatures. The capacity for air conditioning applications (evaporating temperature in the range 0 to 1O⁰C) is typically 75% that of R-134a.

A principal object of the present invention is therefore to provide a heat transfer composition which is usable in its own right or suitable as a replacement for existing refrigeration usages which should have a reduced Greenhouse Warming Potential, yet has a capacity and energy efficiency (which may be conveniently expressed as the "Coefficient of Performance") ideally within 20% of the values, for example of R-134a, preferably within 10% of these values, and even more preferably within 5% of these values. It is known in the art that differences of this order between fluids are usually resolvable by redesign of equipment and system operational features without entailing significant cost differences.

In certain preferred embodiments, the capacity and energy efficiency of blends according to the invention may exceed those of R-134a.

In accordance with one aspect of the invention, there is provided a composition which may be a heat transfer composition comprising: (i) R-1225ye; and

(ii) at least one further compound (refrigerant) selected from carbon dioxide (R-744); fluoromethane (R-41); difluoromethane (R-32); fluoroethane (R- 161); 1,1,1-trifluoroethane (R- 143 a); 1,1,1,2-tetrafluoroethane (R-134a); 1,1,2,2- tetrafluoroethane (R-134); dimethyl ether; heptafluoropropane (R-227ea); propane (R-290); propene (R-1270); isobutane (R-600a); n-butane (R-600); 2,3,3,3- tetrafiuoropropene (R-1234yf); 1,1-difiuorocyclopropane; 1,1,2- trifluorocyclopropane; 1 ,1,2,2-tetrafluorocycloproρane; pentafluorocyclopropane, or ammonia, or mixtures thereof. In a preferred embodiment, the further refrigerant is selected from R- 134a, dimethyl ether, R-161, R-32, R-744, R-41, R-290, R-1270, ammonia, R-600 or R- 1243zf.

In further preferred aspect of the invention, there is provided a composition which may be heat transfer composition comprising: (i) R-1225yeE; (iϊ) R-32, R-161 or R-152a; and

(iii) at least one further compound (refrigerant) selected from carbon dioxide (R-744); fluoromethane (R-41); fluoroethane (R-161); 1,1,1- trifluoroethane (R-143a); 1,1,1,2-tetrafluoroethane (R-134a); 1,1,2,2- tetrafluoroethane (R- 134); dimethyl ether; heptafluoropropane (R-227ea); propane

(R-290); propene (R-1270); isobutene (R-600a); n-butane (R-600); 2,3,3,3- tetrafluoropropene (R-1234yf); 1,1-difluorocyclopropane; 1,1,2- trifluorocyclopropane; 1,1,2,2-tetrafluorocyclopropane; pentafluorocyclopropane, pentafluoroethane (R- 125) or ammonia, or mixtures thereof.

In a preferred aspect of this embodiment, the further refrigerant is R- 134a or R- 125.

In a highly preferred aspect, the R-32, R-161 or R-152a is R-32, and the further refrigerant is R- 134a.

In a further preferred aspect, the R-32, R-161 or R- 152a is R- 152a, and the further refrigerant is R- 125.

In further preferred aspects, there may be provided ^' ternary heat transfer compositions comprising R-1225yeE, R-161 and R- 134a; R- 1225YeE₇ R-161 and R-125; and R-1225yeE, R-125 and R-32. . . In yet a further preferred aspect of the invention, there is provided a composition which may be a heat transfer composition comprising:

(i) R-1225yeE;

(ϋ) R-32; (iii) R-1234yf; and

(iv) at least one further compound (refrigerant) selected from carbon dioxide (R-744); fluoromethane (R-41); fluoroethane (R-161); 1,1,1- trifluoroethane (R- 143a); 1,1,1,2-tetrafluoroethane (R- 134a); 1,1,2,2- tetrafluoroethane (R- 134); dimethyl ether; heptafluoroproane (R-227ea); propane (R-290); propene (R-1270); isobutane (R-600a); n-butane (R-600); 1,1- difluorocyclopropane; 1,1,2-trifluorocyclopropane; 1,1,2,2- tetrafluorocyclopropane; pentafluorocyclopropane, pentafluoroethane (R- 125) or ammonia, or mixtures thereof.

In a preferred facet of this aspect of the invention, the further refrigerant is R-134a

In yet a further preferred aspect of the invention, there is provided a composition which may be a heat transfer composition comprising:

(i) R-1225yeE; (ii) R-32;

(iii) R-125; and

(iv) R-161 or R-152a

Preferably, any resultant heat transfer composition has a GWP less than the refrigerant it is intended to replace, for example R- 134a or R-407C.

In the context of the invention, unless otherwise specified, when we refer to a R-

1225yeE component we mean a composition having a content of R-1225yeE in the R-1225ye component which is at least 95% E isomer, more preferably at least 98% E isomer, more preferably at least 99% E isomer, and which may in some instances be pure E isomer. The remaining minor component of any such R- 1225yeE or R-1225ye composition will be the Z isomer.

Some particularly preferred specific heat transfer compositions according to the invention are set out below (all parts for any given composition total 100 and are expressed on a weight basis):

- R-125 (1 to 3 parts): R-152a (1 to 12 parts): R-1225yeE (85 to 98 parts);

- R-125 (1 to 4 parts): R-161 (1 to 3 parts): R-1225yeE (93 to 98 parts);

- R-161 (1 to 3 parts): R-134a (1 to 10 parts): R-1225yeE (87 to 98 parts); - R-32 (1 to 3 parts): R-125 (1 to 3 parts): R-125a (1 to 12 parts); R-

1225yeE (82 to 97 parts);

- R-32 (1 to 3 parts): R-125 (1 to 3 parts): R-161 (1 to 5 parts): R-1225yeE (89 to 97 parts).

In addition to these the following specific heat transfer compositions are also preferred:

- R-32 (1 to 9 parts): R-34a (4 to 8 parts): R-1234yf (4 to 52 parts): R- 1225yeE (39 to 78 parts);

- R-32 (3 to 9 parts): R-134a (4 to 8 parts): R-1234yf (4 to 24 parts): R- 1225eE (59 to 79 parts) - this composition is preferred as it provides the best capacity and COP match with evaporator glide of less than 5°C;

- R-32 (3 to 7 parts); R-134a (4 to 6 parts): R-1234yf (4 to 28 parts): R- 1225yeE (59 to 78 parts) - this composition is preferred as it has a GWP less or equal to 120 with a strict COP greater than or equal to 100; - R-32 (1 to 3 parts): R-134a (4 to 6 parts): R-1234yf (4 to 52 parts): R-

1225yeE (39 to 78 parts) - this composition is preferred as it has an evaporator glide less than or equal to 2.5°C with a capacity of greater than or equal to 80% of that of R-134a and with good COP match.

Amounts of compositions mentioned herein, including in the claims, are by weight unless otherwise stated. Preferably, the nature and amount of the further refrigerant is such that the resultant binary (or greater) mixture is non-flammable. As used herein, "nonflammable" refers to compounds or compositions which are determined to be nonflammable as determined in accordance with ASHRAE Standard 34 incorporating the ASTM Standard E-681 methodology according to Addendum p34 dated 2004, the entire content of which is incorporated herein by reference. The test used for determination is described in Clause X.2.4.1 "Leaks under storage/shipping conditions", and represents the worst case of fractionation.

Compositions according to the invention typically have improved capacity compared to R-1225ye alone, and also typically have improved capacity compared to R-1225yeE. In one facet, the incorporation of a relatively small proportion of further refrigerant(s) (component (ii) of the composition of the broadest aspect of the invention), which further refrigerant(s) may be flammable, have a higher GWP, or both, may provide a resultant heat transfer composition having both a low GWP and substantially no flammability characteristic and relatively small temperature "glide", yet provide improved capacity and optionally improved Coefficient of Performance.

Temperature glide, which can be thought of as the difference between bubble point and dew point temperatures of a non-azeotropic mixture at constant pressure, is a characteristic of a refrigerant; so if it is desired to replace a fluid with a mixture then it is often preferable to have similar or reduced glide in the alternative fluid.

Compositions according to the invention may conveniently be considered not azeotropic, "near azeotropic" or "azedtrope-like", and indeed may be considered to be "non-azeotropic". That is, they will exhibit temperature glide on vaporisation or condensation. To this end, temperature "glide" in relation to refrigerant mixtures is the temperature change that occurs on evaporation or condensation of the refrigerant mixture in the heat exchangers of a refrigerant apparatus.

We refer in this context to a standardised (simplified) vapour compression refrigeration cycle, which comprises: an evaporator, a compressor, a condenser and an expansion valve, with appropriate pipework and controls etc. The evaporator operates at low pressure and the condenser at high pressure. The refrigerant is fed as a liquid from the condenser through the expansion valve. The drop in pressure results in a portion of the liquid vaporising so that the fluid entering the evaporator is a mixture of liquid and vapour.

The condenser glide is the difference between the dew and bubble point temperatures of the fluid mixture at the condensing pressure. The dew point temperature for a fixed pressure is the temperature at which the first drop of liquid can be condensed. The bubble point temperature at the same pressure is the temperature at which the first bubble of vapour can be evaporated.

The dew point is higher than the bubble point for a mixture exhibiting temperature glide. As pressure increases then the difference between dew and bubble points decreases. In refrigeration systems the lowest pressure (evaporator pressure) is normally designed to be 1 atmosphere (to prevent inward leakage of air) and the highest pressure is normally selected to be 25 bar or less (the cost of pressure vessels etc. increases as pressure rises).

The evaporator glide is the difference between the dew point temperature and the inlet temperature to the evaporator. This inlet temperature is determined by the proportion of vaporisation that has occurred on the initial expansion of feed liquid, so the evaporator inlet temperature is between the dew and bubble points at evaporator pressure. Conveniently, the composition comprises the at least one further refrigerant in an amount of from about 1 to about 30% by weight of the composition.

Advantageously, the composition comprises the at least one further refrigerant in an amount of from about 1 to about 10% by weight of the composition.

Preferably, the composition comprises the at least one further refrigerant in an amount of from about 1 to about 6% by weight of the composition.

Advantageously, the composition comprises the at least one refrigerant in an amount of from about 1 to about 5% by weight of the composition.

In some embodiments the composition is azeotrope-like, though in certain highly preferred embodiments the composition may be considered non-azeotropic.

Conveniently, the composition has a GWP of about 750 or less.

Advantageously, the composition has a GWP of about 500 or less.

Preferably, the composition has a GWP of about 250 or less.

Conveniently, the composition has a GWP of about 150 or less.

Advantageously, the composition has a GWP of about 100 or less.

The heat transfer compositions according to the invention generally have substantially similar thermodynamic characteristics to those they might replace, but will typically have significantly lower Greenhouse Warming Potential.

The heat transfer compositions are suitable for use in existing designs of equipment, and are compatible with all classes of lubricant currently used with established HFC refrigerants. They may be optionally stablized or compatibilized with mineral oils by the use of appropriate additives.

Preferably, the composition further comprises a lubricant.

Conveniently, 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-olefms) and combinations thereof.

Advantageously, the composition further comprises a stabiliser.

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

Conveniently, the composition further comprises an additional flame retardant.

Advantageously, the additional flame retardant is selected from the group consisting of tri-(2-chloroethyl)-phosphate, (chloropropyl)phosphate, tri-(2,3- dibromoρropyl)-phosphate, tri-(l,3-dichloroproρyl)-phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminium trihydrate, polyvinyl chloride, a fiuorinated iodocarbon, a fluorinated bromocarbon, trifluoroiodomethane, perfiuoroalkyl amines, bromo-fluoroalkyl amines and mixtures thereof.

Preferably, the composition is a refrigerant composition.

According to another aspect of the invention, there is provided a heat transfer device containing a composition of the invention.

Preferably, the heat transfer device is a refrigeration device. Conveniently, the heat transfer device is selected from group consisting of automotive air conditioning systems, residential air conditioning systems, commercial air conditioning systems, residential refrigerator systems, residential freezer systems, commercial refrigerator systems, commercial freezer systems, chiller air conditioning systems, chiller refrigeration systems, heat pump systems.

Advantageously, the heat transfer device contains a compressor. The compressor may be centrifugal type or may be any positive-displacement type; for example rotary vane, scroll, swash-plate, screw or piston designs.

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

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

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

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

Preferably the foam comprises a composition of the invention.

According to another aspect of the invention, there is provided a sprayable composition comprising a material to be sprayed and a propellant comprising a composition of the invention. According to a further aspect of the invention, there is provided a method for cooling an article which comprises condensing a composition of the invention and thereafter evaporating said composition in the vicinity of the article to be cooled.

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

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

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

According to a further aspect of the 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 invention, and separating the substance from the solvent.

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

According to a further aspect of the invention, there is provided a mechanical power generation device containing a composition of the invention. Preferably, the mechanical power generation device is adapted to use a Rankiαe Cycle or modification thereof to generate work from heat.

According to another aspect of the invention, there is provided a method of retrofitting a refrigeration device comprising the step of removing an existing heat transfer fluid, and introducing a composition of the invention.

In some circumstances, it is preferred for the compositions to have a GWP of about 150 or less. However, for other applications, it may be acceptable for the composition to have a higher GWP, for example a GWP of up to 250, 500 or 750.

The GWP values of the candidate additional fluids dictate the maximum allowable percentages for each application. Internationally accepted GWP values for selected refrigerant fluids of the invention are as follows:

Fluid GWP Fluid GWP

R-134a 1300 R- 152a 140

R-161 12 R-1270 3

R-41 140 R-227ea 3500

R-125 3400 R-143a 4300

CO₂ 1 R-32 550

R-600a 3 R-290 3

If the additional refrigerant has a GWP lower than the desired value then the maximum amount in the composition is dictated by considerations of flammability and similarity of the resulting mixture to the fluid it is intended to replace.

If the additional refrigerant has a GWP higher than the desired value then the GWP value may also be used to set a preferred composition range. For example, if a GWP of less than 150 is required and the fluid to be replaced is R-134a and in addition the mixture is required to be non-flammable then the preferred compositions of selected additional refrigerants having GWP higher than 150 are as follows:

R-32 6% weight basis; R-134a 9% weight basis; R-227ea 4% weight basis; R-125 4% weight basis.

If the desired GWP is sufficiently high (providing that it is lower than the fluid which the invention replaces) then it is possible to mitigate the flammability of a first additive replacement by adding a second or further additive replacement to the mixture; this allows the use of somewhat higher proportions of the flammable additive.

For example a mixture of R-32 (10%); R-125 (10%) and R-1225ye (80%) will have a GWP of 403. Its refrigeration capacity is very similar to R- 134a (estimated as typically 100-104% that of R- 134a) and it has similar COP characteristic.

For example, the existing refrigerant fluid R-407C is a ternary mixture of R-32, R- 125 and R-134a in the proportions of 23%/25%/52% by weight and has a GWP of 1650. A suitable replacement fluid for this refrigerant can therefore be a mixture of R-32, R-125 and R-1225ye. The additive refrigerant in this case is a mixture of R-32 and R-125, such that the mass ratio of R-125 to R-32 in the mixture is at least 1:1, which ensures non-flammability of the resultant mixture. If a non- flammable mixture of R-32/R-125/R-1225ye is used to replace the 52% of R-134a in the R-407C composition, the resulting mixture will have a similar performance to R-407C but will have a GWP that is substantially lowered compared to that of R-407C. The above example teaches that the optimal matching of replacement properties may require the use of more than one additional fluid, so the replacements of the invention can encompass ternary or higher mixtures.

The refrigerant compositions may be altered by the skilled man to suit the application requirements and flammability characteristics so desired. In particular he may choose to add components such as CF₃I, which are known to reduce or suppress flammability, to the refrigerant mixtures of the invention. However, in many preferred aspects of the invention, because of the potential toxicity and reactivity of CF₃I, compositions according to the invention may be substantially free (e.g. containing less than about 3%), and ideally totally free of CF₃I.

For the ternary and quaternary compositions according to the invention, such compositions were found to have surprising properties, in particular in relation to properties which are important to the performance of the composition in air conditioning, especially mobile (i.e. car) air conditioning systems, in particular when they are required to approach the performance and characteristics of R- 134a.

Flammability measurements have been carried out on mixtures of R-32 in air with R-1225yeE and R-134a as flammable diluents. It has been found that the maximum concentration of R-32 in R-1225yeE to ensure the mixture is nonflammable in air under test conditions at 100⁰C test temperature is 69% R-32 by volume. The maximum amount of R-32 in R-134a at the same test temperature that give non-flammable mixtures in air is 72% R-32 by volume. A conservative assessment criterion has therefore been used; the maximum concentration of R-32 in the fluid vapour should be 68% vol/vol to ensure non-flammability.

This assessment has been carried out for blends containing R-134a between 0 and 10% by weight in the blend. Higher levels of R-134a have not been used in this assessment as the total GWP is desired to be lower than 150. The GWP figures used in this study are: R-32 = 55O₅ R-134a = 1300 and R-1225ye = 10. A replacement fluid for R- 134a in air conditioning system will have a number of desirable properties. These include:

* A volumetric capacity within 90% of R-134a;

• Energy efficiency (expressed as Coefficient of Performance) within 95% of R- 134a, or ideally comparable or better than R-134a;

• Operating pressures similar (preferably within about 10%);

• Compressor discharge temperature similar (within 10 degrees Celsius); • Non-flammable according to requirements of ASHRAE standard 34 Addendum p34 (2004 version);

• Temperature "glide" lower than about 5 degrees Centigrade; and

• GWP less than 150 for European F-Gas directive compliance in mobile air conditioning (MAC) applications.

In many embodiments preferred compositions according to the invention are "non- azeotropic" as described above; these notably include the ternary and quaternary compositions described herein. Such compositions may also be called zeotropes, zeotropic mixtures, and non-azeotropic refrigerant mixtures (NARMS). Such compositions exhibit varying degrees of glide during boiling or condensation, and also exhibit differences in vapour and liquid composition at equilibrium.

Examples Example 1

The data in Table 1 provides illustration of the performance of exemplar blends, which are not limiting, for the replacement of R- 134a. The thermodynamic properties used to calculate the performance have been derived as follows:

The Peng Robinson equation of state has been used to calculate gas density, enthalpy and entropy data and has been used to predict latent heat of vaporisation and vapour equilibrium data for the mixtures of interest. The basic properties required by this equation (critical temperature, critical pressure and acentric factor) of the fluids with the exception of the fluorinated propenes R-1234yf and R-1225ye were taken from reliable sources; chiefly the NIST Webboolc site http ://webbook.nist. go v. The critical properties of R- 1234yf were determined by measurement using a static cell. The critical properties of R-1225ye were estimated using the boiling point for the isomeric mixture of -18⁰C and Joback's group contribution method. The acentric factor for R-1234yf was calculated from measurements of the vapour pressure. The acentric factor for R-1225ye was estimated using the Lee-Kesler correlation. Ideal gas enthalpy data for the propenes were also estimated using the Joback group contribution method. All of these estimation techniques are described in the text "The Properties of Gases & Liquids" by RC Reid, JM Prausnitz & BE Poling, 4^th edition, published McGraw- Hill.

The Peng Robinson equation uses a binary interaction constant to describe the vapour liquid equilibrium of binary pairs. This constant was set to zero where no data were available for mixture pairs; otherwise its value was chosen to give a good representation of the known equilibrium data at temperatures close to 0°C. Binary data for pairs among the fluids R-32/R-125/R-134a were obtained from measurements published in M. Nagel, K. Bier, Int. J. Refiig.^' 18 (1995) 534-543. Binary data for R-1225ye with R-1234yf were taken from US Patent Application US2005/0233932A1. Binary data for R-32 with CO₂ were taken from Rivollet et al. Fluid Phase Equilibria 218 (2004), 95-101. Binary data for R-32 with propane were taken from Fluid Phase Equilibria 199 (2002) 175-183. Binary data for R-1270 (propene) with R-134a and R-152a were taken from Kleiber FluidPhase Equilibria 92 (1994) 149-194. Other data were measured using a static cell technique to measure the total pressure of a mixture of known composition. The data were then regressed using Barker's technique with the data points weighted using the maximum likelihood principle to account for measurement errors in temperature and pressure to fit the required binary interaction parameters for use with the equation of state. AU references to literature and publication sources are included herein by reference in the relevant part.

Example 2

The ASHRAE Standard 34 (relating to safety classification of refrigerants) specifies a series of tests for flammability assessment in its Addendum p34. These require measurement or prediction using a verified computer model of the degree to which fractionation affects the concentration of flammable species in the refrigerant vapour and/or liquid phases. This work has focussed on the Addendum p34 test protocol for assessing the vapour concentration in an initially 90% filled cylinder when cooled to 10° C above its bubble point at atmospheric pressure and subjected to mass removal by vapour withdrawal until the cylinder is devoid of liquid. This is because the flammable component in these blends, R-32, is also the most volatile, so it will be most highly enriched in the vapour phase during fractionation. The other test protocols specified in Addendum p34 will result in less severe fractionation of the R-32.

Fractionation assessment has been carried out by computer model according to the conditions specified in the p34 protocol. The "worst case formulation" (WCF) has been estimated by taking the nominal "as-charged" mass ratios of each component in the blend, adding 0.5% to the mass of flammable component (R-32) and subtracting 1% from the mass of the non-flammable components (R- 134a and R-

1225ye). For example the blend having "as-charged" formulation of R-32/R- 134a/R-1225ye (6%/7%/87% by weight) has a WCF set of mass ratios of these components of 6.5/6/86.

The fractionation of the blend has been modelled using the Peng Robinson equation of state to correlate the vapour liquid equilibrium of the system. The equation parameters have been optimised using measured vapour liquid equilibrium data for the binary pairs R-32/R-1225ye and R-32/R-134a. The equilibrium between R-134a and R-1225ye has been modelled as ideal. The compositions modelled are shown in Table 2:

Assessment of cycle performance for ternary blends of R-32/R-134a/R-1225ye(E) - summary

Compositions quoted are R32/R134a/R1225yeE in mass %

Cells marked * correspond to compositions where the worst case fractionated formulation at the low temperature 90% fill test case (as per ASHRAE p34) will have flammable vapour according to the specified ASHRAE ρ34 test protocol at 100 C

Actual

R32:R1225ye Evaporator Condenser Discharge volumetric Evaporator Condenser Volumetric Relative Relative

Fluid mass ratio GWP pressure pressure temperature flow glide glide capacity COP capacity COP bar(a) bar(a) ⁰C AπrVhr K K kJ/m³

R134a 1300 3.48 11.61 82.6 16.8 0.0 0.0 2143 3.25 100.0% 100.0%

0/10/90 0.000 139 2.48 8.48 74.9 23.1 0.3 0.4 1558 3.27 72.7% 100.6%

0/4/96 0.000 62 2.41 8.26 74.3 23.8 0.1 0.2 1515 3.27 70.7% 100.6%

2/10/88 0.023 150 2.64 9.14 76.8 21.5 1.6 3.0 1677 3.27 78.3% 100.6%

3/4/93 0.032 78 2.66 9.25 77.2 21.2 2.1 4.0 1695 3.27 79.1% 100.7%

3/9/88 0.034 142 2.72 9.42 77.6 20.8 2.2 4.0 1729 3.27 80.7% 100.6%

4/8/88 0.045 135 2.76 9.7 78.4 20.2 2.8 5.0 1779 3.27 83.0% 100.6%

K) 5/0/95 0.053 37 2.78 9.73 78.5 20.2 3.3 6.0 1784 3.27 83.2% 100.7%

5/8/87 0.056 140 2.87 10.01 79.2 19.6 3.4 5.9 1838 3.28 85.8% 100.9%

6/8/86 0.057 146 2.96 10.31 79.9 19.0 3.9 6.6 1896 3.28 88.5% 100.9%

6/4/90 0.067 94 2.91 10.18 79.6 19.3 3.9 6.8 1869 3.28 87.2% 100.9%

7/7/86 0.069 138 3.04 10.57 80.6 18.5 4.4 7.4 1947 3.28 90.9% 100.9%

6/7/87 0.070 133 2.95 10.28 79.8 19.1 3.9 6.7 1889 3.28 88.1% 100.9%

8/6/86 0.081 131 3.11 10.83 81.2 18.0 5.0 8.0 1998 3.29 93.2% 101.2%

8/0/92 0.087 53 3.04 10.64 80.7 18.4 5.0 8.3 1959 3.29 91.4% 101.1%

8/7/85 0.093 144 3.12 10.87 81.3 18.0 4.9 8.0 2005 3.29 93.6% 101.2%

9/4/87 0.103 110 3.18 11.06 81.7 17.6 5.5 8.7 2043 3.29 95.3% 101.2%

9/6/85 0.106 136 3.2 11.12 81.9 17.5 5.5 8.6 2056 3.29 95.9% 101.2%

10/6/84 0.119 141 3.29 11.41 82.5 17.1 5.9 9.1 2112 3.29 98.6% 101.2%

Actual

Fluid mass ratio GWP pressure pressure temperature flow glide glide capacity COP capacity COP

11/0/89 0.124 69 3.31 11.49 82.7 16.9 6.5 9.8 2131 3.30 99.5% 101.5%

11/5/84 0.131 134 3.36 11.65 83.1 16.7 6.4 9.5 2162 3.30 100.9% 101.5%

12/4/84 0.143 126 3.44 11.90 83.6 16.3 6.8 10.0 2211 3.30 103.2% 101.5%

12/6/82 0.146 152 3.46 11.96 83.7 16.2 6.7 9.9 2223 3.30 103.7% 101.5%

13/6/81 0.161 158 3.55 12.23 84.3 15.8 7.1 10.2 2278 3.30 106.3% 101.6%

* 15/0/85 0.176 91 3.66 12.58 85.1 15.3 8.0 11.1 2351 3.31 109.7% 101.8%

*15/4/81 0.185 143 3.70 12.70 85.4 15.2 7.9 10.8 2374 3.31 110.8% 101.7%

*15/6/79 0.190 168 3.73 12.76 85.5 15.1 7.8 10.7 • 2385 3.30 111.3% 101.7% .

* 18/6/76 0.237 185 3.99 13.54 87.2 14.2 8.6 11.2 2540 3.31 118.5% 101.8%

* 18/4/78 0.237 159 3.97 13.48 87.0 14.2 8.7 11.3 2529 3.31 118.0% 101.8%

*20/0/80 0.250 118 4.10 13.86 87.9 13.8 9.3 11.9 2609 3.31 121.8% 101.9%

*21/4/75 0.280 175 4.22 14.23 88.7 13.4 9.3 11.6 2679 3.31 125.0% 101.8%

*21/6/73 0.288 201 4.25 14.29 88.8 13.4 9.2 11.4 2689 3.30 125.5% 101.7%

*24/4/72 0.333 191 4.48 14.95 90.2 12.8 9.7 11.6 2821 3.30 131.7% 101.6%

*25/0/75 0.333 145 4.52 15.08 90.5 12.6 10.1 11.9 2848 3.30 132.9% 101.7% bJ *24/6/70 0.343 217 4.50 15.01 90.4 12.7 9.6 11.4 2831 3.30 132.1% 101.5%

^W *27/4/69 0.391 207 4.73 15.66 91.8 12.2 9.9 11.5 2957 3.29 138.0% 101.3%

*27/6/67 0.403 233 4.75 15.72 91.9 12.1 9.8 11.3 2966 3.29 138.4% 101.2%

*30/0/70 0.429 172 4.94 16.24 93.1 11.7 10.3 11.6 3070 3.29 143.3% 101.1%

*30/4/66 0.455 224 4.98 16.35 93.4 11.7 10.0 11.2 3087 3.28 144.1% 101.0%

*30/6/64 0.469 249 5.00 16.41 93.5 11.6 9.9 11.1 3096 3.28 144.5% 100.9%

*35/0/65 0.538 199 5.34 17.36 95.7 11.0 10.2 10.9 3275 3.26 152.9% 100.4%

*36/4/60 0.600 256 5.46 17.68 96.4 10.8 9.8 10.5 3334 3.25 155.6% 100.1%

*36/6/58 0.621 282 5.48 17.74 96.5 10.8 9.6 10.3 3343 3.25 156.0% 100.1%

*39/4/57 0.684 272 5.69 18.33 97.9 10.4 9.5 10.0 3449 3.24 161.0% 99.6%

*39/6/55 0.709 298 5.71 18.38 98.0 10.4 9.4 9.8 3457 3.23 161.3% 99.5%

A number of important features are to be found from the compositions shown in Table 2. In particular, there is a range of compositions for which a COP is found which is higher than that of R- 134a. As R-32 is added to the blend, the COP increases above that for R- 134a, peaks and then declines. The effect has been found to be not sensitive to the addition of R- 134a to the system. To attain maximum COP, it is preferred that the mass ratio of R-32 to R-1225yeE in a blend containing both of them (binary, ternary or quaternary) lies between 0.20 and 0.35, though the COP of the blend is higher than that of R-134a when the mass ratio of R-32:R1225yeE is between 0 and 0.6.

Since an important objective is to reduce the emission greenhouse gases, increasing the energy efficiency of a R-134a replacement, especially in (but not limited to) a mobile air conditioning systems is desirable, as well as reducing the direct greenhouse warming potential of refrigerant. In the context of mobile air conditioning systems, this is because the running of an air conditioning system is powered by burning car fuel, and hence releasing CO₂ into the atmosphere.

ha addition, the fractionation analysis shows that blends having a mass ratio of R- 32:R-1225yeE of greater than about 0.16:1 generate flammable vapours at the - 20° C fractionation analysis condition. Hence keeping the mass ratio of these two components below this threshold is beneficial.

Additionally, the evaporator temperature glide increases as R-32 is added to the mixture. Temperature glides of 5K or lower are attained when the mass ratio of R-32 to R-1225yeE is less than 0.081.

Further, it has been advantageously found that the volumetric capacity of blends containing R-32 and R-1225yeE is 90% or more of the capacity of R-134a when the mass ratio R-32:R-1225yeE is 0.056:1 or higher.

In relation to preferred compositions containing both R-32 and R-1225yeE, the mass fraction R-32 should be up to 0.6 of the mass fraction of R-1225yeE in the composition to maximise the COP. Additionally, the mass fraction of R-32:R- 1225yeE should be up to about 0.25 (i.e 0 to 0.25) to ensure maximised COP with a "non-flammable" classification. Also, the mass ratio of R-32:R-1225yeE should be up to about 0.081 to keep the glide of the composition as 5°C or less.

Also, the mass ratio of R-32:R-1225yeE should be between 0.056 and 0.081 to keep the capacity of the composition within 10% of that of R-134a, with a glide less than 5⁰C.

A composition comprising a mass ratio of 5 to 7 parts R-32, 6 to 8 parts R-134a and 86 to 88 parts R-1225yeE (the sum of all parts being 100), preferably 6:7:87 R-32:R-134a:R-1225yeE, which has a mass ratio of R-32:R1225yeE of 0.07 combines these beneficial attributes.

Example 3

Tables 3 to 7 show similar information to that shown in the context of Example 2 for different formulations.

In the ensuing tables lines marked * correspond to compositions where the worst case fractionated formulation at the low temperature 90% fill test case (as per ASHRAE p34) will have flammable vapour according to the specified ASHRAE p34 test protocol at 100°C.

TABLE 4 e

tive P .4% .8% .1% .3% .4% .5% .6% .7% .8% .8% .9% .2% 4% 6% 8% 0% 2% 3% 7% .1% 3% .4% 5% 5% 6% 7% 8% 9% 1% 3% 5% % %

%

Example 3

Refrigerant blends according to the invention were tested in freezer and refrigerator environments. The blends were tested according to ISO 5155, and accordingly utilized an Electrolux larder fridge ER6641T, Electrolux Freezer EU6241T, Artificial food packages, RL22H lubricant, 2 Clock hour meters, 2 Power consumption meters, 8 K type thermocouples, 1OK type thermocouples, Datalogger, R-134a and a blend according to the invention comprising 87% wt R-1225yeE (99% pure E isomer), 7% wt R-134a and 6% wt R-32.

Both the fridge and the freezer were maintained 30 cm from the floor. In the freezer, the top shelf held 5 packages, the top drawer 15 packages, the middle drawer 18 packages and the bottom drawer 18 packages. In the fridge, the top shelf held 17 packages, the middle shelf 17 packages, the bottom shelf 17 packages and the bottom drawer 11 packages.

Artificial food packages were made batch wise in accordance with the recipe found in ISO 5155. The 'food' was cut into blocks of 50mm x 100mm x 100mm and wrapped in cling film. They were placed inside the cabinets in order to fill the unit. Four packages contained a T type thermocouple in the centre. The middle packages of each shelf in the appliances contained the thermocouples.

The compressor was modified to accommodate an oil drain at the sump and a charging port on the service pipe. A K type thermocouple was attached to the sump, the suction line and the discharge line. On K type thermocouple was fixed 30cm above the cabinet and one 30cm below the cabinet. The original oil and refrigerant were removed and weighed, the oil was degassed and then weighed again. The same amount was replaced as fresh RL22H. The system was evacuated for fifteen minutes before charging R- 134a.

The cabinets were switched on and allowed to run for five days to ensure the packages had reached the correct temperature and the system had equilibrated. The cabinets were in an air-conditioned cubical set at 25°C. The thermocouples were connected to a data-logger. The cabinets were fitted with a clock meter and plugged into a power consumption meter. The initial power and time readings were taken and the temperatures were set to record hourly.

The 134a experiment was repeated at 23⁰C and 27°C to obtain a temperature correction factor.

Results The test measured run time and energy consumed over a specified total elapse time as detailed in the ISO standard. The column labelled delta- KWH shows the energy consumed in operation over that time period. The column labelled delta-Hours shows the amount of time for which the refrigerant compressor was in operation over the same period. This allows derivation of the refrigeration capacity and the Coefficient of Performance (COP). The raw data were corrected using the temperature calibration curve to an equivalent mean ambient temperature.

It was noted that the temperatures in the freezer were lower with the blend than with R-134a, more marked for the top two measurements.

The composition comprising 87% wt R-1225yeE, 7% wt R-134a and 6% wt R-32 exhibits a COP within 10% of R- 134a.

Claims

1. A heat transfer composition comprising: (i) R-1225ye;

(ii) at least one further refrigerant selected from carbon dioxide (R- 744); fluoromethane (R-41); difluoromethane (R-32); fluoroethane (R-161); 1,1,1- trifluoroethane (R-143a); 1,1,1,2-tetrafluoroethane (R-134a); 1.1,2,2- tetrafluoroethane (R-134); dimethyl ether; heptafluoroproane (R-227ea); propane

(R-290); propene (R-1270); isobutane (R-600a); n-butane (R600) 2,3,3,3- tetrafluoropropene (R-1234yf); 1,1-difluorocyclopropane; 1,1,2- trifluorocyclopropane; 1,1,2,2-tetrafluorocyclopropane; pentafluorocyclopropane, or ammonia.

2. A heat transfer composition comprising: (i) R-1225yeE;

(ii) R-32, R- 161 or R- 152a; and (iii) at least one further refrigerant selected from carbon dioxide (R-

744); fluoromethane (R-41); fluoroethane (R-161); 1,1,1-trifluoroethane (R-143a);

1,1,1,2-tetrafluoroethane (R-134a); 1,1,2,2-tetrafluoroethane (R-134); dimethyl ether; heptafluoroproane (R-227ea); propane (R-290); propene (R-1270); isobutane (R-600a); n-butane (R-600) 2,3,3,3-tetrafluoroρroρene (R-1234yf); 1,1- difluorocyclopropane; 1,1,2-trifluorocyclopropane; 1,1,2,2- tetrafluorocyclopropane; pentafluorocyclopropane, pentafluororethane (R-125) or ammonia or mixtures thereof.

3. A heat transfer composition comprising: (i) R-1225yeE; (ii) R-32;

(iii) R-1234y£ and

(iv) at least one further refrigerant selected from carbon dioxide (R- 744); fluoromethane (R-41); fluoroethane (R-161); 1,1,1-tiifluoroethane (R-143a); 1,1,1,2-tetrafluoroethane (R-134a); 1,1,2,2-tetrafluoroethane (R-134); dimethyl ether; heptafruoroproane (R-227ea); propane (R-290); propene (R-1270); isobutane (R-600a); n-butane (R-600); 1,1-difluorocyclopropane; 1,1,2- trifluorocyclopropane; 1 , 1 ,2,2-tetrafluorocyclopropane; pentafluorocyclopropane, or ammonia or mixtures thereof.

4. A heat transfer composition comprising: (i) R-1225yeE;

(ii) R-32; (iii) R-125; and (iv) R-161 or R-152a.

5. A composition according to claim 2 or claim 3, wherein the further refrigerant is R-143a or R-125, preferably R-134a.

6. A composition according to claim 2, wherein the R-32 or R-161 is R-32.

7. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-1225yeE, R- 152a and R-125.

8. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-1225yeE, R-161 and R-134a

9. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-1225yeE, R-161 and R-125.

10. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-1225yeE, R-125 and R-32.

11. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-125 (1 to 3 parts), R-152a (1 to 12 parts) and R-1225yeE (85 to 98 parts), all parts being by weight.

12. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-125 (1 to 4 parts), R-161 (1 to 3 parts) and R-1225yeE (93 to 98 parts), all parts being by weight.

13. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-161 (1 to 3 parts), R-134a (1 to 10 parts) and R-1225yeE (87 to 98 parts), all parts being by weight.

14. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-32 (1 to 3 parts), R-125 (1 to 3 parts), R- 152a (1 to 12 parts) and R-1225yeE (82 to 91 parts), all parts being by weight.

15. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-132 (1 to 3 parts), R-125 (1 to 3 parts), R- 161 (1 to 5 parts) and R-1225yeE (89 to 97 parts), all parts being by weight.

16. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-32 (1 to 9 parts), R-134a (4 to 8 parts), R- 1234yf (4 to 52 parts) and R-1225yeE (39 to 78 parts), all parts being by weight.

17. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-32 (3 to 9 parts), R-134a (4 to 8 parts), R- 1234yf (4 to 28 parts), and R-1225yeE (59 to 79 parts), all parts being by weight.

18. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-32 (3 to 7 parts), R-134a (4 to 6 parts), R- 1234yf (4 to 28 parts), and R-1225yeE (59 to 78 parts), all parts being by weight

19. A composition according to any one of the preceding claims wherein the heat transfer composition comprises R-32 (1 to 3 parts), R-134a (4 to 6 parts), R- 1234yf (4 to 52 parts) and R-1225yeZ (39 to 78 parts), all parts being by weight.

20. A composition according to anyone of the preceding claims, wherein the composition has a Coefficient of Performance within 10% of the fluid it is intended to replace, for example R-134a.

21. A composition according to any one of the preceding claims, wherein the composition has a capacity greater than R-1225ye and/or R-1225yeE.

22. A composition according to any one of the preceding claims, wherein the composition is non-azeotropic.

23. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE in the composition is between 0.20 and 0.35: 1.

24. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE in the composition is below 0.16:1.

25. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE is less than 0.081 :1.

26. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE is less than 0.6:1.

27. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE is 0.056:1 or higher.

28. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE is between 0.06 and 0.08.

29. A composition according to any one of the preceding claims, wherein the mass ratio of R-32 to R-1225yeE is 0.07:1.

30. A composition according to an}' one of the preceding claims, wherein the composition comprises 5% to 7% R-32, 6% to 8% R-134a and 86% to 88% R- 1225yeE, preferably 6% wt R-32, 7% wt Rl 34a and 87% wt R-1225yeE.

31. A composition according to any one of the preceding claims, wherein the R-1225yeE component comprises at least 95% E isomer.

32. A composition according to claim 31, wherein the R-1225yeE component comprises at least 98% E isomer.

33. A composition according to any one of the preceding claims which has a GWP of about 150 or less.

34. A composition according to any one of the preceding claims which has a GWP of about 100 or less.

35. A composition according to any one of the preceding claims comprising 5 to 7 parts R-32 or R-161, preferably R-32, 6 to 8 parts R-134a or R-125, preferably R-134a, and 86 to 88 parts R-1225 yeE, the sum of all parts being 100.

36. A composition according to any one of the preceding claims comprising 2 to 4 parts R-32, 2 to 4 parts R-125, 3 to 6 parts R-161 and 86 to 93 parts R-1225 yeE, the sum of all parts being 100, all parts being by weight.

37. A composition according to any one of the preceding claims comprising 2 to 4 parts R-32, 2 to 4 parts R-125, 10 to 13 parts R-152a, and 79 to 86 parts R- 1225 yeE, the sum of all parts being 100, all parts being by weight.

38. A composition according to any one of the preceding claims comprising 2 to 4 parts R-161, 2 to 4 parts R-125, and 92 to 96 parts R-1225 yeE, the sum of all parts being 100, all parts being by weight.

39. A composition according to any one of the preceding claims further comprising a lubricant.

40. A composition according to Claim 39 wherein the lubricant is selected from mineral oil, silicone oil, polyalkyl benzenes (PABs), polyol esters (POEs)₅ polyalkylene glycols (PAGs), polyalkylene glycol esters (PAG esters), polyvinyl ethers (PVEs)₃ poly (alpha-olefms) and combinations thereof.

41. A composition according to any one of the preceding claims further comprising a stabiliser.

42. A composition according to Claim 4139 wherein the stabiliser is selected from diene-based compounds, phosphates, phenol compounds and epoxides, and mixtures thereof.

43. A composition according to any one of the preceding claims further comprising an additional flame retardant.

44. A composition according to Claim 43 wherein the additional flame retardant is selected from tri-(2-chloroethyl)-phosphate, (chloropropyl)phosphate, tri-(2,3-dibromopropyl)-phosphate, tri-(l,3-dichloropropyl)-phosphate, diammonium phosphate, various halogenated aromatic compounds, antimony oxide, aluminium trihydrate, polyvinyl chloride, a fiuorinated iodocarbon, a fmorinated bromocarbon, trifluoroiodomethane, perfmoroalkyl amines, bromo- fluoroalkyl amines and mixtures thereof.

45. A composition according to any one of the preceding claims wherein the composition is non-flammable.

46. A composition according to any one of the preceding claims which is a refrigerant composition.

47. A heat transfer device containing a composition as defined any one of Claims 1 to 46.

48. A heat transfer device according to Claim 47 which is a refrigeration device.

49. A heat transfer device according to Claim 48 which is selected from automotive air conditioning systems, residential air conditioning systems, commercial air conditioning systems, residential refrigerator systems, residential freezer systems, commercial refrigerator systems, commercial freezer systems, chiller air conditioning systems, chiller refrigeration systems, and heat pump systems.

50. A heat transfer device according to Claim 48 or 49 which contains a compressor.

51. A blowing agent comprising a composition as defined in any one of Claims 1 to 45.

52. A foamable composition comprising one or more components capable of forming foam and a composition as defined in any one of Claims 1 to 45.

53. A foamable composition according to Claim 52 wherein the one or more components capable of forming foam are selected from polyurethanes, thermoplastic polymers and resins, such as polystyrene, and epoxy resins or mixtures thereof.

54. A foam obtainable from the foamable composition of Claim 52 or 53.

55. A foam according to Claim 54 comprising a composition as defined in any one of Claims 1 to 45.

56. A sprayable composition comprising a material to be sprayed and a propellant comprising a composition as defined in any one of Claims 1 to 45.

57. A method for cooling an article which comprises condensing a composition as defined in any one of Claims 1 to 45 and thereafter evaporating said composition in the vicinity of the article to be cooled.

58. A method for heating an article which comprises condensing a composition as defined in any one of Claims 1 to 45 in the vicinity of the article to be heated and thereafter evaporating said composition.

59. A method for extracting a substance from biomass comprising contacting the biomass with a solvent comprising a composition as defined in any one of Claims 1 to 45, and separating the substance from the solvent.

60. A method of cleaning an article comprising contacting the article with a solvent comprising a composition as defined in any one of Claims 1 to 45.

61. A method for extracting a material from an aqueous solution comprising contacting the aqueous solution with a solvent comprising a composition as defined in any one of Claims 1 to 45, and separating the substance from the solvent.

62. A method for extracting a material from a particulate solid matrix comprising contacting the particulate solid matrix with a solvent comprising a composition as defined in any one of Claims 1 to 45, and separating the substance from the solvent.

63. A mechanical power generation device containing a composition as defined in any one of Claims 1 to 45.

64. A mechanical power generation device according to Claim 63 which is adapted to use a Rankine Cycle or modification thereof to generate work from heat.

65. A method of retrofitting a refrigeration device comprising the step of removing an existing heat transfer fluid, and introducing a composition as defined in any one of Claim 1 to 458.

66. A heat transfer composition substantially as hereinbefore described.