# Patent

## Title
Composition containing 1,1,-difluoroethane and 3,3,3-trifluoropropene

## Abstract

Compositions containing 1,1-difluoroethane and 3,3,3-trifluoropropene, that can be used in multiple fields of application. The composition may include from 25 to 65 mol % of 1,1-difluoroethane and from 75 to 35 mol % of 3,3,3-trifluoropropene at a temperature of between −25° C. and 25° C. and a pressure of between 1 and 6 bar. The composition may further include hydrogen fluoride. The composition may include from 20 to 55 mol % of HF, 30 to 40 mol % of 1,1-difluoroethane and 30 to 40 mol % of 3,3,3-trifluoropropene.

## Background
The present invention relates to compositions comprising 1,1-difluoroethane and 3,3,3-trifluoropropene that are useful in many fields of application.
Fluids based on halocarbons have thus found many applications in various industrial fields, in particular as heat transfer fluid, propellants, foaming agents, blowing agents, gaseous dielectrics, monomer or polymerization medium, support fluids, agents for abrasives, drying agents and fluids for energy production units.
Particular importance is given to fluids that have a low impact on the environment.
The advantage of using azeotropic or quasi-azeotropic fluids is that they do not fractionate during evaporation processes and act (almost) as a pure body. However, it is difficult to identify novel fluids that meet these characteristics, since azeotropes cannot be predicted.


The subject of the present invention is an azeotropic or quasi-azeotropic composition comprising the compounds 1,1-difluoroethane and 3,3,3-trifluoropropene.
In what follows, the following compounds represent:

    
    
        1,1-difluoroethane: HFC-152a or 152a
        3,3,3-trifluoropropene: HFO-1243zf or 1243zf
    
    


The expression “quasi-azeotropic” has a broad meaning and is intended to include the compositions that are strictly azeotropic and those that behave as an azeotropic mixture.
A mixture is azeotropic when the pressure at the dew point is equal to that at the bubble point, which means that the vapor composition is equal to that of the condensed liquid.
A mixture is considered to be quasi-azeotropic when the pressure difference between the pressure at the dew point and the pressure at the bubble point is less than or equal to 5%, on the basis of the pressure at the bubble point.
According to one embodiment, the composition according to the invention comprises, preferably essentially consisting of, from 10 to 80 mol % of 1,1-difluoroethane and from 90 to 20 mol % of 3,3,3-trifluoropropene.
According to one embodiment, the composition according to the invention comprises, preferably essentially consisting of, from 20 to 70 mol % of 1,1-difluoroethane and from 80 to 30 mol % of 3,3,3-trifluoropropene.
According to one particularly preferred embodiment, the composition according to the invention comprises, preferably essentially consisting of, from 25 to 65 mol % of 1,1-difluoroethane and from 75 to 35 mol % of 3,3,3-trifluoropropene and has a boiling point between −25° C. and 25° C. at a pressure of between 1 and 6 bar.
According to another embodiment, the composition according to the invention also comprises hydrogen fluoride.
According to one embodiment, the composition according to the invention comprises, preferably essentially consisting of, from 20 to 55 mol % of HF, 30 to 40 mol % of 1,1-difluoroethane and 30 to 40 mol % of 3,3,3-trifluoropropene.
The invention also relates to the use of a fluid comprising the composition according to the invention as heat transfer fluid, propellants, foaming agents, blowing agents, gaseous dielectrics, monomer or polymerization medium, support fluids, agents for abrasives, drying agents and fluids for energy production units.
Preferably, the invention relates to the use of a fluid comprising the composition according to the invention as heat transfer fluid in a heat pump or refrigeration plant.
The invention also relates to a heat transfer plant comprising a vapor compression circuit containing a fluid comprising a composition according to the invention as heat transfer fluid or containing a heat transfer fluid as described above.
According to one embodiment, the plant is selected from mobile or stationary plants for heating via a heat pump, for air conditioning, and in particular for motor vehicle air conditioning or for centralized stationary air conditioning, for refrigeration or for freezing and Rankine cycles; and which is preferably an air conditioning plant.
The invention also relates to a process for heating or cooling a fluid or a body by means of a vapor compression circuit containing a heat transfer fluid, said process successively comprising the evaporation of the heat transfer fluid, the compression of the heat transfer fluid, the condensation of the heat fluid and the expansion of the heat transfer fluid, in which the heat transfer fluid is a fluid comprising a composition according to the invention.
The expression “heat transfer fluid” is understood to mean a fluid capable of absorbing heat by evaporating at low temperature and low pressure and of releasing heat by condensing at high temperature and high pressure, in a vapor compression circuit.
A heat transfer fluid optionally comprises one or more additives which are not heat transfer compounds for the envisaged application. The additives may in particular be selected from lubricants, nanoparticles, stabilizers, surfactants, tracers, fluorescent agents, odorous agents and solubilizing agents, as are well known to a person skilled in the art.










TABLE 1









Pressure: 1 bar absolute
Pressure 3 bar absolute














Temper-
Mole
Mole
Temper-
Mole
Mole



ature
(%) of
(%) of
ature
(%) of
(%) of


Azeotrope
(° C.)
152a
1243zf
° C.
152a
1243zf





152a/
−25
29
71
3
60
40


1243zf

## Claims

1. An azeotropic composition at a pressure of 3 bar having 60 mol % 1,1-difluoroethane and 40 mol % 3,3,3-trifluoropropene.