Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF

Inventor(s):

NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CONTRACT NO. NAS 7-918

TECHNICAL SUPPORT PACKAGE

on

NEARLY AZEOTROPIC MIXTURES TO REPLACE REFRIGERANT 12

J. Jones

for August 1992

NASA TECH BRIEF Vol. 16, No. 8, Item #122

from

JPL NEW TECHNOLOGY REPORT NP0-18030n528

NOTICE

Neither tho United Sta1n Government, nor NASA, nc>. ""' poroon acting on behalf a1 NASA:

New Technology Report

a. Makes any watrenty or representallon, oxpren or Implied, with rHpltCI o1 the accuracy, comple111nan, or uaefulnao of !he Information contalllld In l>la document. or that 1he use o1 any ln1ormallon, oppatatua, mothod, or proo•u dlsoloted In 1hll document mllll' not infringe privately owned rights; or Prepared by: C. J. Morrissey

TSP assembled by:

b. Auumes tll'r'f liabUitlea wflh reepect to the usa of. or lor damagM resulting from the use ol, any lnlormallon. apparalus. method or proc,... disclosed In this document.

JPL Technology Utilization Office

pp. i, 1-39

JET PROPULSION LABORATORY CALII'ORN lA INSTITUTE 01' TI!CHNOLOGY

PASADENA, CALIFORIIIA

AUGUST 1992

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f Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTUR_E_S_.P_D_F ________ _

Nearly Azeotropic Mixtures To Replace Refrigerant 12 These mixtures woulq cause less damage to the ozone layer of the atmosphere.

NASA's Jet Propulsion Laboratory, Pasadena, California Measurements haw lndicatoo that a

nurmer of nearly azaolroplc fluid mixtures have saturation pressures similar to that of Refrigerant 12 (A12, dlchlorodifluoro­methane, CCizF2) while being about 2'1. as damaging as A121S to the ozone layer In the atmosphera Moreover, theSe mix· tures are of low taxlelty, are nonflammable, and are more compatille with cort'Je!ltioJ1. allubricaling oils than is Refrigerant 134a (R134a, 1,1,1.2·1etra~ CH:fCF3; boiling temperature -27.89 "C), whiCh Is row the leading replacemenl m R12. The mixtures rnay be usable In commercial, autOIT10tiYe. and i'lousell;)ij relrlgerabs am air condltioners.

R12, OON used In many relrtgeratorsand air COildiUoners, Is known lo leak from theSe machines and ascend Into the up. per atmosphere, where It damages the 020ne layer. Ooe of the proposed replace­ITI8flls, R134a, does not damage the ozone layer because It contains no chlorine. But because of its lack of chiofine, conven· tlmal lubricating oils do not dissolve as well in It, and consequently compressors are 111\ely to fall prematurely thrCIUQh non­lubricated wear. Dupont has recently pat· ented an ol~patible ternary mixture of R22 (chlorodlfluoromelhane, CHelF~ bol~ ing te~ature -40.76 "C), R152a(1,1<1~ fluoroethane, CHF2CH3: boiling \enl)era· ture -25.00 "C), and R124(2<:1Jioro.1.1,1.2· tetrafluoroethane, CHCIFCF 3; boiling tem· perature -12.00 "C). Because the boiling IE!f1ll9111tures of these three fluids differ slg­nlficartly, and because the mixture of them is not azeotroplc.leaks could substantial· ly change the composition and, thereby, the pressure characteristics of this fluid.

A thorough search of flolds and hun· dreds of meastw'ements P"QV!ded five near· ly azeolrl:lPc mixtures (see !able) of A134a, R152a. R124. and R142b (chlorodHiuoro­ethane, CH3CCtF 2; boiling temperature -9.70 •c> that have tow boiling-point spreads,low toxicity, and low ozone-<lafn. aging capabilty, thai are nonflammable,

-------and that are more COITllalible with COill/ell'

tlonal oils than Is R134a. The data from the tests lnckata that the pressure of any of the. combinations in the table Is nearly equal to the pressure of R12, and thus the mix· tures rnay be a good "drop-ill substitute" for R12. Because the mixtures are nearly azeotroplc, the overal COfl"'P)SStion should not be significantly altered by leakage.

LaboratOfY. In addition 10 R134a. R152a a/so has no ozone..<1ePetio P?teruial. A124 am R142b bod1 have ozooe'\lepletlon potentialS that are less lhan 5 percent of that of R12. Thus all fi~~e of the mixtures of the table have ozone-depletion potentials about 2% that of R12. The frve mixturas are nonflamma­ble, although R152a and R142b by them­selves are flarYrnable. Because R124 and R142b both contain chlorine, they are ex· peeled to cissolve oil more effectively than R134a does; the addition of them 10 R134a Is therefore expected to help R134a dis· solve conventional lubricating oils.

In accordance with Public Law 96-517, the contractor has elected to retain title to this Invention. Inquiries concerning rights for Its oommetelal use should be ad· dreSS#KitD

Edward Ansen Director of Patents and Ucensing MaH Stop 305-6 Callfomla Institute of Technology 1201 East California Boulevard Pasadena, CA 91125

This work was done by Jack A Jones of Gaitech tor NASA's Jet Propulalon

Refer to Nf'0.18030, VOlume 8l!d number of this NASA Tech Briefs Issue, 8l!d the page number. (Vol. 16 No 8 Page 46) . .

MIXTURI!$

Mlxtu~ Component 1\ Component B • Component C * Numbtr

1 o.e <At~< 1.0 Rl24 < 0.5 2 0.5 < A1~ < 1.0 RU2b < 0.5 3 0.5 < R1~ < 1.0 R124 < 0.5 R142b < 0.5

• 0.5 < A1~ < 1.0 R1e2a < o.s A124 < 0.5 5 0.5 < Rl~ < 1.0 R152a < 0.5 R142b < 0.5

'o.o < cB+ q < 0.2 Proportions of component refrJgeranta ar• given In mole fractions.

These Blna!J ond Ternary Nearty Areotroplc Mixtures of llqulda are potential replace­ments for ~fngerant 12, whlcllls now commonty used. Each of these mixtures has an ozone-depletion potential teaa than one.Oundredtfl that of Refrlgeront 12.

IDENTIFICATION OF COMPONENT REFRIGERANTS

Aefrlge<anl FOfmula Name Normal Bolling Temperatur•. oc

At lola CH2FC"3 t,1,1,2.Tetrafluoroelhane -27.89 A152a CHF~H3 t,t·Difluoroelhane -25.00 R124 CHCIFCl'3 2·Chloro-1,1,1,2·1elrafluoroethane -12.00 R142b CHJCCIF2 Chlorodlfluoroethane -9.70

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/ Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF ____________ Pa~e

LOW-OZONE DAMAGING FLUID MIX SUBSTITUTES FOR REFRIGERANT 12

The work described here was carried out at the Jet Propulsion L~boratory, California Institute of Technology, uncier contract wii.h the N.a~.ional Aerounatics and Space Administration.

Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not constitute or imply its endorsement by the United States Government or the Jet Propulsion Laboratory, California Institute of Technology.

ABSTRACT

Test measurements made at JPL have indicated a number of near-azeotropic fluid mixtures have saturation pressures similar to Refrigerant 12, b~t the mixtures are at least 100 times less damaging to the earth's ozone layer. Furthermore, the mixtures are of low toxicity, are non· flammable, and are likely to have an improved coefficient of performance and better compatibility with oil than Refrigerant 134a, the present leading replacement for Refrigerant 12. Although the newly discovered JPL blends are likely to cost more than the recently patented Dupont ternary blend, they are at least four times less ozone-damaging than the Dupont blend, and they are at least twice as azeotropic.

JNTRODUCTION

Earlier In the earth's history, before the stratospheric ozone layer had formed, animals and plants were mostly confined to a protective underwater environment. As plants generated oxygen, which slowly diffused up to the stratosphere, a protective ozone layer was built which absorbed harmful ultraviolet (UV) radiation. As stated by Shell (Reference 1), "Living things were then able to climb out of the primordial slime and onto land." We have ever since been blessed with nature's stratospheric •sunscreen•. In 1974, however, F. Sherwood Rowland, a chemist at the University of California, Irvine and ~arlo Molina, then a postdoctoral fellow and now a senior research scientist at JPl, became the first two people to document the potential catastrophic destruction of tha earth's ozone layer by man's

____ chlorofluorocarbon (CFC) release Into the atmosphere (Ref. 2). The chlorine in CFCs acts as a catalyst in the breakdown of ozone. A single atom of chlorine can help turn tens of thousands of ozone molecules into an impotent pile of oxygen molecules.

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i Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF -------

Rowland and Molina's theories have more recently been confirmed, with the recent discovery of ozone "holes" both over the Arctic and the Antarctic and a reduction of as high as 5% (over the last 17 years) of the ozone layer over latitudes corresponding to the United States (Ref. 3). There is, in fact, strong evidence that human skin cancer rates have already started to soar (Ref. 1), and that the ocean's phytoplankton, which is the very basis of the earth's food chain, has been reduced by 25%. The phytoplankton, which live very near to the ocean's surface, are not afforded the same UV protection that lower living fish and plants have. There is also evidence that the earth's climate is warming up due to the "greenhouse effect• resulting from man's dumping of CFC's and other infrared-trapping gases into the atmosphere.

PROTECTIVE LEGISLATION

Starting from the time CFC's were first discovered by Thomas Mldgely of General Motors in 1928 until 50 years later, CFC's had routinely been used as aerosol propellants, industrial cleaners, foam insulation, and as refrigerants. In 1978, however, the U.S. Environmental Protection Agency {EPA) announced that It was phasing out the use of CFC's for most nonessential aerosol propellants (Ref. 4). Then, on September 16, 1987, a landmark international agreement to protect the ozone layer was completed in Montreal, Canada (Ref. 5). The agreement, known as the "Montreal Protocol" was negotiated under the sponsorship of the.United Nations Environment Programme (UNEP). It sets up a worldwide process to control substances that could deplete the ozone layer, and calls for a reduction in consumption and _ production in 1993 to 8~ of the level of 1986 CFC's, and a further reduction to 50% of the I986 level by 1998.

Numerous other legislative proposals have been submitted, including a total ban of common air conditioners for automobiles {Ref. 6). It seems more likely, however, that alternative refrigeration systems can reduce CFC consumption, as alternatives to CFC's are now in the process of doing for the aerosol, industrial cleaner, and foam insulation industries.

POSSIBLE SUBSTITUTES FOR Rl2

Numerous researchers have proposed alternatives that eliminate the use of Rl2, which is the most commonly used refrigerant for automobile. air conditioners and other systems. Alternate refrigeration cycles, such as absorption cycles, Stirling cycles, evaporative cooling, etc. have been proposed, but none seems to have the overall efficiency, versatility, economy and long-life inherent in the traditional J-T cooling refrigeration cycle. Thus, an alternative refrigerant seems to be the answer.

The Montreal Protocol is applied specifically to Rll, Rl2, Rl3, Rl13, Rl14, and RllS, all of which have an extremely long life expectancy in the atmosphere, and which can thus slowly diffuse to the stratosphere and wreak havoc with the ozone. Other refrigerants, which have no chlorine or which are more readily 'decomposed in the atmosphere, pose little or no danger to the

------·earth's ozone 1 ayer.

No single refrigerant is known that can adequately repl~J R12. The closest single substitute to Rl2, iQ terms of being non-toxic, non-flammable, and non· ozone-damaging is RI34a. This refrigerant, however, contains no chlorine at

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all, and since chlorine makes CFC's soluble in oils •. Rl34a Is not soluble in the present lubricating oils used to lubricate the compressors. Furthermore, Rl34a is not quite as energy-efficient as Rl2. Although It is rather expensive (expected bulk cost will be 3 to 5 times that of RJZ), it Is still the present leading contender as a replacement for Rl2, assuming adequate soluble lubricating oils are discovered.

Numerous fluid mixtures have been proposed that overcome Rl34a's disadvantages. These mixtures generally fall into the category of azeotropic or non-azeotropic. For an azeotropic mixture, the mixture's properties do not change with evaporative leakage. Since most air conditioning systems do, in fact, tend to leak, with time, it seems that an azeotropic or near-azeotroplc mixture would be desired. The number of flu.lds suggested for mixing the replicate Rl2 properties is limited for a variety of reasons {to be discussed in the next section). Seven researcher groups have proposed using the various fluids listed in Table 1 as potential fluid mixture replacements for R12 (Ref. 8-14). With the exception of the Dupont mixture, which was recently patented, there has been absol'utely M publication of any azeotropic or near­azeotroplc mixture data for potential Rl2 substitutes. The Dupont blend, which mixes R22, RI52a, and RI24, has an ozone depletion potential of about twenty times less than Rl2, It is non-flammable, and is expected to be non­toxic {toxicity studies in progress for Rl24). Although the blend is non­azeotropic, its vapor pressure only changes by about 9.4% with a 50% leakage, and thus It may be acceptable for commercial use. Its oil-compatibility is better than Rl34a and the blend is expected to be considerably cheaper.

The goal of this project, then, has been to find an azeotropic or near azeotropic blend of fluids that surpasses both Rl34a and the Dupont mixture.

POTENTIAL FLUIQ MIX CANDIDATE SELECTIONS

Table 2 contains a listing of all potential fluids that have normal boiling point (NBP's) from -az•c to -s•c. Next to each fluid is listed acceptance or rejection comments. In summary, of all the fluids considered, only six appear to be acceptable in terms of cost, toxicity, ozone-damage-potential, other environmental damage potential and relative flammability. These six are R23, R22, Rl34a, RI52a, Rl24, and R!42b. A seventh fluid, Rl34, was also selected for testing, even though its toxicity data is unknown since it was felt that its properties were likely to be very similar to R134a, which was not immediately available at the commencement of testing.

Although the total number of binary, ternary, and quaternary combinations of these seven fluids is over 1000, by selectively choosing binary combinations that were considered "most-likely-to-succeed" in forming acceptable azeotropes. the binary field was reduced from 42 combinations to 17 combinations_. Based on these results, the "most-likely-to-succeed" ternary combinations were then reduced from 210 to 5, and the quaternaries were subsequently reduced from 840 to only 1. Thus the total number of actual combinations tested was reduced to only 23.

-----It should be mentioned that we attempted to discover only the more common positive or negative azeotropes, and thus the far less common saddle azeotrope (similar to the Dupont ble~ near-azeotrope) would not be detected in the aforementioned methodology.

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TEST PROCEDURE

A relatively simple test to determine the existence of a binary azeotrope is to measure the pressure of a binary mixture at various concentrations of one component in the other at a fixed temperature (Ref. 15). A maximum in the vapor-pressure curve of the binary mixture is indicative of a minimum-boiling azeotrope while a minimum In the vapor-pressure curve of the binary mixture is indicative of a maximum constant-boiling mixture. In Figures 1 and 2 are plotted typical curves of the former and latter type, respectively. The straight lines in each figure are the partial pressures of each component of the solution calculated from Raoult's law for ideal gases. The sum of the ordinates of these two lines, shown dotted and designated at A+ B, fs the vapor pressure of the mixture predicted from Raoult's law. The actual vapor­pressure curve of the mixture in Figure I shows a maximum at Z, while in Figure 2, the vapor-pressure curve of the binary mixture shows a minimum at z. Deviations of mixture pressure from the ideal dashed line in Figures 1 and 2 are caused by intermolecular interactions between the two fluids. If the real mixture pressure was in fact, the dashed line, then the more volatile component A, would preferentially boil, and a vapor leakage would eventually result in only component B remaining in the system.

Near-azeotropic mixtures are mixtures that almost have a maximum or minimum point, I.e. the slopes of the pressure curves are very small. Ternary azeotropes (mixtures of three fluids) have maximum or minimum pressures at some combination of all three fluids.

The test fixture shown in Figure 3 (sketch) and Figure 4 (Photo) was fabricated and numerous potential fluids were purchased. The fluid mole fractions, as determined by pressure additions to the transfer volume, were mixed and allowed to condense in the o•c (+0.1/-0.0°C) fee bath. The pressure was then measured for a number of separate mole fraction ratios for each mixture.

As a test of this procedure, a known azeotrope, RSOO, was tested. RSOO is an azeotropic mixture consisting of 74% Rl2 plus 26% Rl52a. Our data (Figure 5) does, in fact, indicate that an azeotrope occurs, although the Indications are that it occurs at about 30+% Rl52a. Azeotrope mixture combinations are known to vary somewhat with temperature, and thus our measurements at o•c seem to be reasonable compared to the reported valve which was likely taken at room­temperature.

RESULTS ANQ CONCLUSIONS

The results of seventeen binary mixture combinations are shown in Figures 6·22 with an additional 5 ternary mixture combinations in Figures 23-27 and a final quaternary mixture combination in figure 28. Other than the known azeotrope of Rl2 and Rl52a previously tested (Figure 5), none of the other fluids

-------exhibit an actual minimum or maximum pressure occurrence. Numerous fluid combinations, however, have nearly flat pressure characteristics in the pressure range of RI2, i.e. about 44.7 psia, and thus can be considered to be "near-azeotropic".

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The six candidate mixtures that have been selected from this data as potential "drop-ln" substitutes for Rl2 are listed In Table 3 (possible patent pending­Ref.15). Basically, all the combinations Include at least SO% R134a with the remaining 20% to be constituted from one or more of refrigerants Rl24, Rl42b, and Rl52a. All of these combinations are expected to be non-toxic, non­flammable, and near-azeotropic. Toxicity studies are completed for Rl52a and Rl42b and are scheduled for completion for Rl34a around 1992 and for Rl24 shortly thereafter. Furthermore, all combinations should be more oil­compatible than Rl34a, due to the existence of chlorine in Rl24 and Rl42b.

It should be noted that at room temperature or above, the vapor pressure of Rl34a is actually slightly higher than Rl2, and thus at higher temperatures, the six candidate mixtures should actually be expected to more closely approximate Rl2 than does Rl34a by Itself. ln addition, it has been noted that the coefficient of performance {COP) is lower for Rl34a than for Rl2, but that the COP of Rl52a is actually better than that for Rl2 (Ref. 16). Thus, combinations of Rl52a and RI34a will more likely approximate the COP of R12 than does Rl34a by itself. A possible optimum ternary blend for near term use might consist of Rl34a (toxicity tests to be completed in 1992) + Rl42b (for oil compatibility) + RI52a (for improved COP}.

All the listed JPL/CalTech mixtures are expected to be at least 100 times Jess damaging to ozone th~n Rl2, as compared to the Dupont mixture (Ref. S), which is only about ~ less damaging than RIZ. Furthermore, the JPL mixtures tend to be at least twice as azeotropic as the Dupont mixture. Dupont repor~s a 9.4~ pressure drop with a 50% leakage, whereas a measurement of one of the new mixtures (typical of the other mixtures) shows about a 4~ pressure drop, or less, depending on the relatively constituency amount of RI34a (Fig. 29).

It should be noted that the JPL/CalTech blends are likely to be more expensive than the Dupont blend, since the cost of the primary JPL constituent, RI34a, Is expected to be 3-5 times that of RZ2, which is the primary Dupont constituent. The JPL/CalTech blends, however, have advantages of being over twice as azeotropic and having over four times lower ozone-depletion-potential than the Dupont blend. Furthe~ expedient testing and development of these new blends are therefore very strongly urged.

Mknowledgements

The helpful assistance of JPL's Or. Robert Phen in obtaining NASA Technology Utilization funds for this project is greatly appreciated. Also appreciated is the assistance provided by JPL's Or. Gary Blue regarding chemistry compatibility and toxicity information and the technician assistance provided by JPL's J~ Garcia. The delivery of the experimentil refrigerant, Rl34a, from both Flura Corp. and Dupont is also recognized with gratitude, as is the overall list of refrigerant fluids provided by Dr. James Sand of Oak Ridge National Laboratory.

The research described In this paper was carried out by the Jet,Propulsfon ------laboratory, California Institute of Technology, under contract with the

National Aeronautics and Space Administration.

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References * 1. ·Ellen Ruppel Shell, "Weather Versus Chemicals", The Atlantic (Monthly),

May 1987.

z. M. J. Mollna and F. S. Rowland, "Stratospheric Sink for Chlorofluoromethanes: Chlorine atom-catalyzed Destruction of Ozone", ~ 249:810-12, 1974.

3. Richard A. Kerr, "Stratospheric Ozone is Decreasing", Research News, pp. 1489-149Z, March 25, 1988.

4. Federal Regjster, 43 Fr 53 (March 17, 1978), p. 11318.

5. United Nations Environmental Programme (UNEP), "Montreal Protocol on Substances that Deplete the Ozone Layer-Final Act•, 1987.

6. Clay Evans, "Ban of Common Air Conditioners for Autos Sought", Los Angeles Times, July 18, 1989.

7. Robert Pool, "The Elusive Replacements for CFCs", ~. Vol. 242, pp. 664-668, November 4, 1988.

8. Donald B. Bivens and Helen A. Connon, "Halocarbon Blends for Refrigerant Use", U.S. Patent #4,810,403, March 7, 1989, E I Dupont deOemours & Co.

9. Midwest Research Institute, "Chemical Technology and Economics in Environmental Perspectives, Task I, U. S. Dept. of Commerce, PB-251-146, February 1976, p. ZS.

10. Mark 0. Mclinden and David A. Didion, "Quest for Alternatives•, ASHRAE Journal, December 1987, pp. 32-42.

ll. F. A. Creswiclc, S. K. Fischer, and J. R. Sand, "Potential Impacts of CFC Restrictions on Refrigeration and Space-Conditioning Equipment",~ Joyrnal of Refriq., Vol. 11. July, 1988, pp. 217-221.

12. E. A. Vineyard, J. R. Sand, and J. G. Statt, "Selection of Ozone-Safe, Nonazeotropic Refrigerant Mixtures•, ASHRAE Transactions, v. 95, Pt. l, No. 3199, 1989.

13. H. Kruse and V. Hesse, "Possible Substitutes for fully Halog~nated Chlorofluorocarbons Using Fluids Already Marketed", Int'l. Journal of Refr1g., Vol. 11, July 1988, pp. Z76·283.

14. Lewis-B. Weisfeld, "Formulating Away from CFCs-Part II: Alternatives and Solutions", Plastics Compoynding, May/June 1988, pp. 40·43.

15. L. Kuljpers and S. H-111ner, "The CFC Issue and the CFC Forum at the 1988 Purdue IIR Conference". Int J. of Refrig., Vol 12, May 1989.

*PLEASE OBTAIN REFERENCES FROM THE SOURCES LISTED.

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Table 1. Rl2 Fluid Mix Substitute Literature Search

Che• (•c) Ref 8 Ref 9 Ref 10 Ref ll Ref 12 Rei' 13 Ref 14 ~~ I!.AIIIlL lll!f ~ M..IJb£m ~ ~~Kl:llu ~ R2l CHF3 Trifluoro-thana -82.06 X R32 CH2F2 Mathylana Fluorida -51.61

Rl25 CHF2Cf'3 Pentatluoroathana -48.50 X X X

Rl4Ja cu3cF3 Tr i tluoroethane -41.61 X X

R22 CH¢11'1 Ch 1 orodi i'l uoroaethana -40.76 X X X X X

R218 cF1cr,cr3 Octatluoropentana -39.00 X X

R12 CC11Fz Dlchlorodlt.luroaath<ma -29.79

Rllll CClF-<:1'2 Chlorotrifluoroathylena-27. 89 X

Rll4a CH2FCF1 1,1,1,2- -26.50 X X X Tetrafluoroethane

R152a CHF2CH1 1,1-Difluoroethana -25.00 X X X X X

R134 CHFzCHF2 1,1,1,2- -19.72 X Tetrafluoroethana

Rl24 CHC1FCF1 2-Chloro-1,1,1, 2- -12.00 Tatraf1uoroethana

X X X X

Rl24a CHF2CC1F2 l-Ch1oro-1,1,1,2- -10.22 X Tetratluoroetllana

R142b cu3cciF2 Chlorod 1 fluoroethana -9.7 X X X X

Rll8 c,r8 Octafluorocyclobutana -5. Bl X X

Rll. 10 CF1CF2CF2CF3 Pertluorobutane -5.00 X

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Table 2. Potential Rl2 Replacement FlUid Mix Selections

Chell (OC) Accept/ &!fi:ig ~ ~ t!l!.e ~ ~

Z)

~~~~ Tri f 1 uoroJDethane -82.06 A Very low HBP (unlikely good azeo) 13 Chlorotrifluoromethane -81.44 R Ozone daaage 116 CP1d 1 Hexfluoroethane -78.50 R Greenhouse effect 744 C02 Carbon Dioxide -78.44 R Possibly reactive H CH1F Methyl Fluoride -78.39 R Very flamoable 1114 CP2~cPt Tetra!luoroethane -76.211 R Reactive 1141 CH2•CH Vinyl Fluoride -72.22 R Reactive

SF6 Sulfur Hexafluoride -63.78 R Toxic 1381 ~~~~Lm BroiiOtrifluoroaethane -57.75 R Toxic 504 (Azeotrope) -57.22 R ozone daaage 32 g~z~HP Methylene Fluoride -51.61 R Flaa~~able (unlikely good azeo) 1123 Tr i fluoroethane -51.00 R Reactive 125 CH~2CF3 Penta tl uoroethane -48.50 R Too expensive

-y;·f,'~ 1270 CHz•CHCH1 Propylene -47.70 R FlaDU!!able. Toxicity unknown. HJa cH,cF1 Trifluoroethane -47.61 R Possibly toxic 502 R22/Rll5 (Azeotrope) -45.44 R Ozone damage 290 ~~~.r~ Propane -42.07 R Very tlall&abl e 22 Chlorodi fl uoroaethane -40.76 A Low ozone daaaqe 115 CC1F~F1 Chloropentatluoroethane -39.11 R Ozone da•age 218 CP3Ct2CF1 Octafluoropropane -39.00 R Greenhouse affect 161 ~CHF Pluoroethane -37.22 R Very flaJIIIIable 500 ;il1s2a (Azeotrope) -33.50 R Ozone daaaqe C270 CH2CH2CH~ cyclopropane -33.50 R Very l'laii!IMble 717 NH3 A-onia -33.33 R Toxic C216 CFfF2CF2 Perfluorocyclopropene -31.50 R Greenhouse effect 12 Dichloroditluoromethane -29.79 R Ozona damage 505 ~il}ljll (Azeotrope) -29.61 R ozone damage

..,: 1216 ~~~~~~3 Perfluoropropane -29.00 R Reactive 1132 l, 2-Difluoroethane -2R. 00 R Reactive 1113 CClF=CF2 Chlorotr i fl uoroethy 1 ene ·27.89 R Reactive 134a CH2FCF3 1,1,1,2- ·Z6.50 A Toxicity tests in progress

Tetra r 1 uoroethane l52a CHFzCH3 1, 1-Difluoroethane -25.00 A Slightly flammabla

-= ~ ~\AS (C:..J,.-t-C...-\)

'*" = n~~ r~ c~H~\.0

011

[Charlotte Hucker- NASA-NEARLY AZEOTROPIC_M_I_XT_U_R_E_S_._P_D_F _______________ _

Table 2. Potentia I Rl2 Replacement Fluid Mix Selections (Continued)

cham (.C) Accept; .BUtig .f2Dil!lA lWiA m ~ ~

40 cnr;l Methyl Chloride -24.n R Toxic 1131a CC F•CHfl 1-Cbloro-1-fluoroethane -24 .oo R Reactive

If 1261ya cn1cF-c 2 2-Fluoropropene -24.00 R Reactive 11581 CBrFt:;1 Brouopenta t l uoroethane -22.00 R Toxic

>t 1225zc ~~f cn/z 1,1,1, 3 ,3-Pentafluoropane -21.00 R Reactive

134 1, 1, 2, 2-Tetrafluoroethane -19.72 A Toxicity unknown (sill to RlJ4a?) 1122 cuci-clz 1-Cbloro-2, 2- -18.48 R Reactive

Difluoroethane 227ea CF1CHFCF1 1,1,1,2,3,3,3,)- -18.00 R Toxicity unknown

Ill Heptatluoropropane

1243zf cF1cH~CHz 1,1,1-TrifluoroprOp;ilne -18.00 R Reactive 245cb CF1CF2CH1 1,1,1,2,2- -17.72 R Toxicity unlmo~m

Pentafluoropropane 227ca CF1CFzCHFz 1,1,1,2,2,3,3-

Hepta fluoropropane -17.00 R Toxicity unknown

2281 CHBrl' Bro•od if luoromethana -15.00 R Toxic 1140 CHC1•ht2 Chloroethane -lJ.B!I R Reactive 506 Rll/Rll4 (Azeotrope) -u.u R ozone daaaga 124 CHC1FCP1 2-Chloro-1, 1, 1, 2- -12.00 A Low ozone daaage

Tetratluoroethane 600a c4n 1, Isobutana -u. 73 R Very flalllllllbl e 124a CHPzCClFz 1-Chloro-1, 1, 2, 2- -10.22 R t'oxicity unknown

Tetratluoroethane 764 SOz Sulfur Dio><ide -10.00 R Toxic 142b cn1cc1Ffr, Chlorodifluoroethana -9.78 A Low ozone damage 28lea CH1cHFC 2-Fluoropropana -9.19 R Very flaamable 31 CII2ClF Cblorofluoro•eth<>ne -9.11 R Toxic 630 C111NH2 MethylaJOine -6.72 R Very flaiUiable CJ18 CliP a Octafl uorocyclobutane -5.83 R Greenhouse effect Jl.lO ~~lc;,:g~tF, Perfluorobutane -5.00 Greenhouse ef feet 1122a 1-Chloro-l, 2- -5.00 Reactive

Difluoroethana

012

Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF -------------------------------------------------

Table 3. JPL Near-Azeotropic Mixture Replacements for Rl2

Mixture

l

2

3

4

5

6

component A

0.8<Rl34a<l.O

*O.O<(B+C+D)<0.2

Component B* Component C* Component D*

Rl24<0.2

Rl42b<0.2

Rl24<0.2

Rl52a<0.2

R152a<0.2

Rl24<0.2

Rl42b<0.2

Rl24<0.2

Rl42b<0.2

Rl42b<0.2 Rl52a<0.2

All fractions are qiven as molafractions

10

Page 1

013

j Charlotte Hucker- NASA-NEAAL Y AZEOTROPIC MIXTURES.PDF Page 1·

z

MOLE FRACTION OF A

FIGURE 1 MINIMUM·BOIUNG AZEOTROPIC CHARACTERISTICS

ll

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I Charlotte H-ucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF --~------------P_ag~e-1

w a: ;:) Cl) Cl) 1.&.1 cr 0..

A+~-------~----

MOLE FRACTION OF A

A

FIGURE 2 MAXIMUM-BOIUNG AZEOTROPIC CHARACTERISTICS

12

015

I Charlotte Hucker- NASA-NEARLY A-=Z=E=O:__T_R_.::.O_P_IC_M_I_X_TU;_R_E_S:._._PD_F_______________ _ Page ~

FLUIDA _....

FLUIDC ___...

TO VACUUM

TRANSFER MIXING VOLUME

ICE BATH (0°C)

TEST VOLUME

FIGURE 3 A2EOTROPIC GAS MIX TEST APPARATUS SKETCH

lJ

016

jCharlotte Hucker- NASA-NEARLY AZEOTROPIC MIXT_U_R~E_S_.P_D_F _____________ _

017

\_Qharlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF Page 1l

60.---------------------------~

- a a (/) 50- a + + a. - a + a

+ +

Cl) I • 1:1 ... + :::J

:::;; (/) (/) 40-Cl) I ... Q.

30 I . 0.0 0.2 0.4 0.6 0.8 1.0

R152a

FIGURE 5 TEST DATA CONFIRMING KNOWN AZEOTROPE (R500)

018

Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES .PDF Page 1

'40~----------------------------~

-c;; 30 Q. -CD

• .... .... :::1 "' "' 0 20-

CD ... I a.

10 I I I I

0.0 0.2 0.4 0.6 0.8 1.0

A142b

FIGURE 6 BINARY MIXTURE OF R124 + R142B

019

..... - Ill c. - Q)

.. :I Ill Ill Q) .. Q.

~~~.·

,,',

'

45 35.

Iii Iii

~ Iii

li1

u

u

25 Iii

15+-

~~,~

~.--

r-,~

~.--

r-~r

--T-

~ 0.0

0.2

0.4

0.6

R124

0.8

FIGUR

E 7

B!NAR

V MIXT

UR£ O

F R1

34 t

R124

1.0

91 lll

::l.

;

g <D

I c 0 "A

~

I z )>

(j)

)> z m

)>

::0

r- -<

)>

N m

0 -;

::0

10

"1

J 0 s:: x -;

c ::0

m

(j) 'u

0 'i1

020

I Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF Page 2

40.---------------------------~

- Iii • Iii - Iii Ul 30-a. ~ -CD

qJ

~ ... :I Ul Ul 20-CD ... a.

10 I . I I I

0.0 0.2 0.4 0.6 0.8 1.0

R142b

FIGURE 8 BINARY MIXTURE OF R134 + R142B

021

----~----------------------------------~·

Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF Page 2~

~

-~ -"" m-- <::::) a:

+

i r-~ ·a:

~ .... <::::) c:--.1 0 ......- w m• a: a:

9 r-~ ~ .:II

JDio <::> 0 >-

i a me- r-C"! ~ <::::)

5 me- u:

. ~ <::::)

~ g ~

(ISd) a.1nssa.1d

19

022

0 :::T ~

0 ::::::

(!) I ' c:

() ~

~ ' z )>

(/)

)>

:2: m

)>

JJ

r -<

50

~I 01

-I

I ~I .....

s::

Iii x

(/)

40·

Iii -I

Q.

c JJ

.....

ljl m

~

""'0

G)

0, .,

" &.

. 0

:I (/)

(/)

30.

G)

&.. a.

20 I

I I

r 0.0

0.2

0.4

0.6

0.8

1.0

134

FIGUR

E 10

BIN

ARY

MIXT

URE

Of' R

134A

+ R1

34

023

!1

gharlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF Page 2

FIGURE 11 BINARY MIXTURE OF R134A + R142B

024

WT-

------

------

------

-

~ 40

. - G)

.. ~

::l 0 0 30

. G)

.. Q.

20 0.0

I 0.2

AGUR

E12

ljl g

I I

I I

0.4

0.6

0.8

1.0

A152

a

BINAR

Y MI

XTUR

E OF

R13

4A +

R152

A

z )>

(/)

)>

:Z ~ J

)

r -<

)> §I J

)

0 ""0 0 s: x -I

c J)

m

~

""0

0 '"T1

025

' Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF Page2

45.----------------------------

-tn 35 li a. w

Q) ... 1.. w :::J Iii

U) U) 25 ~ Q) 1..

Q.

15 I I I I

0.0 0.2 0.4 0.6 0.8 1.0

R124

FIGURE 13 BINARY MIXTURE OF R152A + R124

026

I Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF Page 2 ------------------------~----------~~-

50.-------------------------~

-f/) 40 i Q. - lp

Q) 'il "'

,_ ~

"' ::::J I f/) f/) 30-Q) ,_

11.

20~--,---~r--r-~,--~---r-.~~-~,--~~~

0.0 0.2 0.4 0.6 0.8 1.0

R134

FIGURE 14 BINARY MIXTURE OF R152A + R134

027

i Charlotte Hucker- NASA-NEARLY AZEOTROPIC _M_IX_T_U_R_E_S_._P_D_F _____________ _ Page

45

I -0 35- EJ a. + - a CD +

~ I. ::s (I) El 0 25

+

CD I. 0.

15;---~-,,r-~---r-,~---~.~~-~.~---J 0.0 0.2 0.4 0.6 0.8 1.0

% R142b

FIGURE 15 BINARY MIXTURE OF R152A + R142B

028

Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF Page2

<:::> -~ c:o a: 1- •

13• c:::> ...

&i

-~ :5

oo::l" w g: c::>

C'l :::> ......- !;<

ED+ a: :i >-

,_."""": ~ ~ 0 c:::>

CD

~ m + !!'!

r-~ w cc: c::> :::> c.!J .. !i:

~ _L .. I I I <:::>

~ ~ ~ ~ <:::> c::> ~ ~

(ISd) a.Jnssa.Jd 26

029

~arlotte Hucker~ NASA-NEARLY AZEOTROPIG MIXTURES. PDF

<:::>

t-

-CC? ~ <:::> a:

1}1 ~--~ ......

oo:f" 0 <::::> ~ 15:! ,... a: ~

-~ <::::> I i5i5

~--~ ~ <::> w

(

a: ;::::, <.!J a:

<::::> . I <:::> ~ g ~

(ISd) 8..10SS8.1d

030

/CI'Jarlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF Page::

C)

--~ ~ c:> &:

-~ t-~ ca ~ C) ...,..

w co-, a: ...... a a: t-"""=

:II >-

C) j 131

-~ ~ w c:> a: :::t

~ <!:1 ;:&:

~ . I C)

~ ~ c:> C'?

(ISd) e..1nssa.Jd 28

031

@§otte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF Page 3

C::\

--~ = CJ ~

a: +

m• 0 f-~ ~

..Q ..... c:::> c:... 0 ~ ....,

E!J ....- QC

a: ~ I-"""'= ~

CJ i m• Q5

~~ c:::> :;!?

LU a:: ;::)

~ ~

• I -~ -- I I . c:::> :;?. g ~ ~ ~ ~

(ISd) a.Jnssa.Jd 29

032

1, Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTUR-ES. PDF '---------- -

Page 3

80

70 ~

-"' 60 Q. - • CD 50-

"' ... 0

:J

"' 0 40 G) ... a.

30--

20 I I I

0.0 0.2 0.4 0.6 0.8 1.0

R152a

FIGURE 20 BINARY MIXTURE OF R22 + R152A

033

i Charlotte Hucker- NASA-NEARLY AZEOT_R_O_P_IC_M_IX_T_U_R_E_S_.P_D_F ____________ _ Page3

<:::)

~

- 00 ~ <:::) ;!

.... &!

,_"C? ca :s C> ....,.. <'? w cc -- 9 a: 0 m

--~ ::I -C)

~ <D

f-~ C> c:;

f5 1- ::;:)

ri C>

I ci 8 C)

....-

(ISd)

034

lCharlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF Page 3:

300,------------------------------

--fb Q, 200--G)

'"' .. N

::J fb fb G) ..

Q.

100- Ill + I

.

0~--~.---~,---~---T~--~--~.~.~-~~--~~

0.0 0.2 0.4 0.6 0.8 1.0

R22

FIGURE 22 BINARY MIXTURE OF R23 + R22

035

IChariotte Hucker - NASA~NEARL Y AZEOTROPIC MIXTURES. PDF

FIGURE 23 TERNARY MIXTURE OF R134A + R134 + R124

32 J2 psi

3/ 77 PSI

100% RIJ4 32 99 psi

100% RIJ4a

]I 00 PSI 28 30 P"

41 2 pst

80:>; Rl34a

52 72 pSI

IQQ7? Rl ?'1

40 I PSI

036

) Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF

FIGURE 24

------ .. ------ . --·-

TERNARY MIXTURE OF R134A + R152A + R142B

42 47 051

I \ I \

100% Rl34a

I \

34

037

- -

Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF

FIGURE 25 TERNARY MIXTURE OF R134A + R152A + R124

----- .. - - . - . -----

42.47 os-t

JOO% Rl34a

I \ I \

I \

35

Page~

038

~rlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF

FIGURE 26 TERNARY MIXTURE OF R134A + R124 + R142B

------- ·- ·-- - -·-·----- .

42 47 OSI

I

. I \

I \

Jo

I 00~ R 134a

\

039

:charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES. PDF

FIGURE 27 TERNARY MIXTURE OF R134A + R134 + R1428

42.47 Pol

100% R 134a

I \ I \

I \

37

040

r CHarlotte Hucker- NASA-NEAAL Y AZEOTROPIC MIXTURES.PE_'=------------

90°/o R134a 10% A142b 41.95

• 41.73

41.54 ~--.;._------4 41.05 1 0% A 124 41 .62 1 0% A 1 52a

80°/o R134a 20% A142b 41.4

• 40.93

• 40.51

40.1 39.7

20% A124 20% A152a

FIGURE 28 QUATERNARY MIXTURE OF R134A + R142B + R124 + R152A

38

Page<

041

I Charlotte Hucker- NASA-NEARLY AZEOTROPIC MIXTURES.PDF

(ij' '(ii

.9: 41 w cc ;::) C/) C/) L.U a: a. 38

37

36

350

FIGURE 29

90% R134a, 10% R124

-----o.-._ ---o.---80% R134a, 20% R124 ~-a.--...... -.. -·~·--..

10 .20 30 40 50 60 70 80 90 100 %FLUID MIXTURE EVAPORATED

PRESSURE CHARACTERISTICS WITH LEAKAGE FOR R134A + R124

39

·~--P__.age_•

042