Solubility of Halogenated Hydrocarbon Refrigerants in Organic Solvents 0 . F. ZELLHOEFER Williams Oil-0-Matic Heating Corporation, Bloomington, Ill.
The solubilities of a number of low-boiling halogenated hydrocarbons in a wide variety of solvents have been determined. From this information several combinations of refrigerant and solvent have been found which are suitable for use in absorption refrigeration units. A number of these solvents are described here for the first time. OF HALOGENATED HYDROCARBONS IN ORGANICSOLVENTS TABLEI. SOLUBILITY
CHFClz CHsCl CClzFz CzHaC1 CHzClz CzClzFi at at at at at at 638 Mm. 2203 Mm. 2693 Mm. 557 Mm. 181 Mm. 786 Mm. Urams per cubic centimeter 0.493 o:iis 0.46 o:i62 0.278 ... 0.218 ... o:iis 3 0.258 0,212 0.36
Formula
Solvent Cellosolve acetate Carbitol acetate Carbitol ethyl ether Dimethyl ether of tetraethylene glycol Diethyl ether of tetraethylene glycol Dimethyl ether of triethylene glycol Carbitol methoxyacetate Butyl Carbitol acetate Diethylene glycol diacetate . 4-Methyl-2-pentanol acetate
...
CFCII at 364 Mm. 0 : 286
...
o:ii6
... ... .. .. .. ...
2,3-Di-8'-ethoxy-+3-ethoxydioxane
y,y'-Dichloro-n-propyl ether Dichloroisopropyl ether a-Fluoronaphthalene Trichlorobenzene 1,1,2,2-Tetrachloroethane
CioH7F C6HaCla ClzCHCHCIz
0.49
0.294
0.258
0.37
0,262 0.194 0.35
0.236 0.204
....
TABLE11. SOLUBILITIES OF DICHLOROMOXOFLUOROMETHANE AND METHYLCHLORIDE IN ORGANICSOLVENTS Solvent
Formula
Butyl Cellosolve n-butyrate Butyl Cellosolve acetate Butyl Cellosolve laurate Tetrahydrofurfuryl ether of butyl Cellosolve Tetrahydrofurfuryl Cellosolve acetate Methyl Carbitol acetate Butyl Carbitol chloride Methyl ether of triethylene glycol acetate Tetrahydrofurfuryl laurate Tetrahydrofurfuryl acetate cr,y-Glycerol diohlorohydrin aoetate Ethyl laurate 2-Ethyl-1-hexanol acetate Furfuryl acetate Ethyl furoate Furfural Tetralin Deoalin Benzotrifluoride
n-CaHoO C H Z ) Z O C O - ~ - C ~ H I n-CaIIoO CHz)nOCOCIt n-C+HoO CHz)zOCO(CHdroCH~
p-fluor omisole
I
CHFClz at 638 Mm.
CHIC1 at 2203 Mm. Gram per cc. 0.65 0.29 0.75 0.32 0.44 0.206
0.75
0.282
( C ~ H I O ) C H Z O ( C H Z ) Z ~ C O C H0.86 ~ 1.00 CHaO(CH2CHzO)zCOCHa 0.63 n-CaHo(OCHzCHdzC1
0.304 0.308
0.91 0.60 0.87
0.30 0.204 0.342
0.55
0.266 0.212 0.272 0.263 0,302 0.276 0.228 0.142 0.300 0.304
0.28
0.48
0.63 0.65 0.76 0.72 0.46 0.24 0.40 0.56
548
A
...
...
...
...
... ...
0:308
...
...
...
...
...
...
...
S PART of a program to develop an ab-
sorption refrigeration machine to become a part of a year-round air-conditioning system, the solubilities of a number of low-boiling halogenated hydrocarbons in a wide variety of solvents were determined. The determinations were made with the solvent a t the usual temperature of the absorbing unit (32' C.) and under the pressure which is exerted by the vapor of the refrigerant a t a temperature of 4.5" C., since it is the solubility of the refrigerant in the absorbing solvent under these conditions that determines the usefulness of a particular system for refrigeration. In the present paper, data are presented on the solubility of dichloromonofluoromethane, methyl chloride, ethyl chloride, dichlorodifluoromethane, dichlorotetrafluoroethane, methylene chloride, and trichloromonofluoromethane in r e p resentative hydrocarbons, ethers, alcohols, al-
IKDUSTRIAL AND ENGINEERING (XEMISTRY
MAY, 1937
549
dehydes, ketones, esters, sulfides, sulfonamides, TABLE 111. SOLUBILITY OF DICHLOROMONOFLTJOROMETHANE and %heir halogen s u b s ti t u t i o n products. IN ORGANIC SOLVENTS Certain requirements in the solvent, such as CHFClz high boiling point, low viscosity, stability at 638 Mm. Formula toward heat, noncorrosive character, etc., Solvent G./cc. were kept in mind in the selection of the com0.57 Cellosolve glycollate pounds tested. After considerable prelimi0.70 Cellosolve succinate 0.75 nary work, dichloromonofluoromethane seemed Cellosolve adipate 0.42 Benzyl Cellosolve to be most promising as a refrigerant, and 0.65 Benzyl Cellosolve acetate 0.59 Methyl Cellosolve phthalate various ethers and esters of the polyethylene 0.51 Butyl Cellosolve phthalate 0.91 glycol derivatives the best solvents for actual Ethylene glycol diacetate Methyl Cellosolve carbonuse. Hence, this combination of refrigerant 0.77 (CHaOCHzCHz0)zCO ate 0.75 CzHsO(CHnCHzO)zCO(CHz)zCOCH Carbitol levulinate and solvents was most extensively investiEthylene glycol diethoxy0.75 (CzHs0CHzCOOCHz)z gated. acetate Diethylene glycol diethIn general, dichlorodifluoromethane is much 0.71 [CzHsOCHnCOOCH~CHzz0 oxyacetate 0.84 CzHsO(CHzCHz0)zCOCdzOC~H~ Carbitol ethoxyacetate less soluble in every solvent tested under the Diethylene glycol dimeth0.71 [CHaOCHzCOOCHzCHzInO oxyacetate test conditions than is dichloromonofluoroMethyl Carbitol methoxymethane. It should also be emphasized that 0.93 CHaO(CHzCHzO)zCOCHz0CHa acetate 0.80 CHs(0CHzCHz)nCl Methyl Carbitol chloride in the solvent series prepared from the polyDitetrah drofurfuryl ether 0.86 [(C4H70)CHzOCHzCHz]zO of dietxylene glycol ethylene glycol derivatives, RO(CH&HZO),R, Tetrahydrofurfuryl Cellothe solubility of dichloromonofluoromethane 0.86 (C4H70)CHiOCHzCHzOCOCH3 solve acetate Triethylene glycol dimethwas not affected greatly by an increase in the 0.72 (CH~OCHnCOOCH~CHzOCHn~~ oxyacetate value x, but was affected by the nature of Di-B-chloroethyl ether of 0.54 [ClCHzCHzOCHzln ethylene glyool the R groups. When these R groups were Methoxyacetate of triethyl0.89 CHsOCHzCOO(CHzCHz0)aCOCHs ene glycol acetate m e t h y 1, e t h y 1, acetyl, methoxyacetyl, or Triethylene glycol diace0.85 ~CHaCOOCHaCHzOCH~Iz tate ethoxyacetyl, good solubility was obtained Dimethyl ether of hexawith all the combinations. However, intro0.88 CHaO (CHnCHzO)&Ha ethy!ene glycol 2,3 - Di - @" - methoxy - 8'duction of an R group which contained a ethoxy-@-ethoxydioxane greater proportion of carbon and hydrogen 0.74 CHz CH-O(CHzCHn0)nCHa than was present in the above mentioned b H t dH-O(CHzCHz0)zCHa groups gave a less satisfactory solvent. I
Methyl ether of triethylene $lycol chloride Trimethylene glycol diacetate Trimethylene glycol dimethoxyacetate Tetrahydrofurfuryl methoxyacetate Tetrahydrofurfuryl b e n ~ o ate Triaoetin Tripropionin Tributyrin Tricaproin Ethylene glycol Diethylene glycol Triethylene glycol Trimethylene glycol Tetrshydrofurfuryl alcohol n-Butyl-n-butyrate Diethyl phthalate Diethyl acetone dioarboxylatc Ethyl levdinate Resorcinol diethyl ether
CHa(OCHzCHdsC1
0.84
(CHaC0OCHz)zCHz
0.90
(CHsOCHzCOOCHz)zCH,
0.77
(CIHIO)CHZOCOCHZOCH~
0.94 0.62 0.73 0.67 0.49 0.51 0.11 0.32 0.40 0.12 0.62 0.76 0.65
(CnHs0COCH~)zCO CH~CO(CHZ)ZCOOCZH~ m-CsH4 (OCzHsh CHzCHz
0.66 0.91 0.52
I-Menthow
CHaC.4
0.71
Diphenylsulfide
CaHssCaHs
\CHCH(CHsjr
\CHzC=O /
0.32
Method of Determining Solubility A copper drum, 4 X 12 cm., is used for saturating the solvent with gaseous refrigerant. On the head of this drum is a needle valve with a two-way outlet. To one outlet is connected an accurate pressure gage, and to the other outlet is connected an S. A. E. fitting for a small copper tube. First, the drum is evacuated to 1 mm. pressure absolute and weighed. Approximately 40 cc. of solvent are drawn into the drum and weighed. This test drum is then connected to a drum of refrigerant, and the connecting line is purged and tightened. The test drum is submerged in a water bath maintained a t 32" C. and agitated, while the gaseous r e f r i g e r a n t is allowed to flow slowly into the test drum. With the solution a t bath temperature, an
TABLEIV. SOLUBILITY OF METHYLCHLORIDE IN ORQANIC SOLVESTS Solvent
Formula
CHaCl at 2203 Mm.
Solvent
Formula
C /cc.
G./ce.
Butyl Cellosolve Butyl Carbitol Lauryl aloohol a,y-Glycerol d/chlorohydrin a,y-Glycerol dibromohydrin Butyl Cellosolve methoxyacetate a,?-Glycerol dichlorohydrin butvrate a,y-Giyoerol dichlorohydrin adi ate m,y-&ycerol dibromohydrin acetate -, 7'-Dichioropropyl carbonate 8 @'-Dichloroethylcarbonate Di-@-chloroethylphthalate Di-n-butyl dichlorophthalate
n-C4HoOCHzCHzOH ~-CIHBO(CHZCHZO)~H CHa(CHn)lrOH (C1CHn)nCHOH (BrCHz)nCHOH
0.23
n-C4HeOCHzCHzOCOCHzOCHs
0.30
0.228
0.116 0.208 0.162
(CICHz)zCHOCO-n-CsH7
0.258
[ (ClCHz)zCHOCOCHzCHz]~
0.178
(BrCHz)zCHOCOCHa (C1CHzCHzCHzO)zCO (C1CHaCHzO)zCO o-CeH4(COOCHzCHzCl)z 0-CoHaClz [COO-n-C4HsIz
0.27 0.244 0.238 0.172 0.17
CHaCl at 2203 Mm.
O-CBHI [COO-n-C4Holz (BrCHzCHz)zO p-ClCsH10CzHs p-BrCsHtOCzHs CeHsOCsHs p-BrCeH4OCsHs Br(CHz a0CeHs Br CHzdHzOCsHs CHClnCCla CHClnCClzCCls (BrCH2)zCHBr m-CioHKX u-CioH7Br o-CeH4Clz o-ClCaH4CsHs o-CHsCsH4O rPO Benzeneaulfonyl-n-butylanilirLe baHsSOzN(n-brHo)CeHo Di-n-butyl phthalate 8 8'-Dibromodiethyl ether pkhlorophenetole Bromophenetole iphenyl ether p-Bromodiphenyl ether y-Bromopropyl phenyl ether 8-Bromoethyl phenyl ether Pentachloroethane asym-Heptachloropropane Tribromohydrin a-Chloronaphthalene a-Bromonaphthalene o-Dichlorobenzene o-Chlorodiphenyl Tri-o-crasyl phosphate
0.194 0.266 0.25 0.248 0.202 0.170 0.234 0.228 0.316 0.212 0.19 0.192 0.184 0.256 0.183 0.178 0.188
TABLEV. Compound
Sp. Gr. a t 24' C. n%'
-Calcd.-
B. P. O
Dimethyl ether of triethyiene-glycol Dimethyl ether of tetraethylene glycol Diethyl ether of tetraethylene glycol Tetrahydrofurfuryl ether of butyl Cellosolve
0.974 1.4233 1.03 0.97
.. . .
PROPERTIHS AND ANALYSESOF NEWCOMPOUNDS
c.
Mol. Formula
216 115-118 (2 mm.)
1.4314 132-134 (12 mm.)
0.948 1.4409
246
Analysis -Found% C
% H
Prepared from
CSHl6O4
53.92 10.19 53.91
10.17
NaOCHzCHzOCHzCHzOCHzCHzONa+
CioHzaOs
54.05
CizHzeOs
57.6
CiiHzzOs
65.28
% C
% H
Yield
% 71
(CHdzSOa 9.84 CHaOCHzCHzONa ClCHzCHzOCHz- 20 CHzCl 10.4 56.6 10.57 CHoCHzOCHzCHzONa ClCHzCHz42 OCHaCHzCl 10.96 64.52 10.85 CHaCHzCHzCHzOCHzCHzONa CHI-CHI
+
9.91 53.98
+
+
..
I
...
Ditetrahydrofurfuryl ether of diethylene glycol
1.076
Dimethyl ether of hexaethyfene glycol
1.052
2,3-Di-p'-ethoxy-8-ethoxydioxane
1.145 1.4430 161-166 (2 mm.)
2,3-Di-p"-methoxy-p'ethoxy-p-ethoxydioxane
1.015
1.4591 210-220 (2 mm.)
CirHzsOs
51.3
Butyl Carbitol chloride
0.993
1.4341
CsHirOzC1
Di-#-chloroethyI ether of ethylene glycol Methyl ether of triethylene glycol chloride Carbitol methoxyacetate
1.196
....
Diethylene glycol dimethoxyacetate Methyl Carhitol methoxyacetate Triethylene glycol dimethoxyacetate Methoxyacetate of triethylene glycol acetate Trimethylene glycol dimethoxyacetate Tetrahydrofurfuryl methoxyacetate
,
199-203 (14 mm.)
CirHza06
61.31
9.49
61.39
9.30
clcHz-~~c""z +
I:3ZLzoNa
....
195-199 (14 mm.)
'4
C I ~ H ~ O 54.19 ~
9.68 53.20
9.82
CizHzrOe
9.10 54.4
8.9
54.54
25
CiCHnCHzOCHzCHzCl
CHsOCHzCHzOCHzCHzONa ClCHzCHzOCHzCHzCl
+
18
83
215
8.6
51.37
8.3
1.056
.... ....
CliHZOO7
9.38 CHaCH~CHzCHz0CH~,CHzOCHzCHnOH SOClz pyridine 37.96% C1 37.95% C1 HOCHzCHz0CHzCHz0CHzCHzOH 78.5 SOCla 19.5% C1 18.9% C1 CHsOCHzCHzOCHzCHzOCHzCHzOH+ 60 SOClz pyridine 52.42 8.74 51.65 8.83 CHaCHzOCHzCHzOCHzCHzOH 86 CHsOCHzCOCl pyridine 48.00 7.20 48.07 7.24 HOCHaCHzOCH+3HzOH CHaOCHs- 67 COCl pyridine 50.00 8.33 50.02 8.17 CHsOCHzCHzOCHzCHzOH CHs- 56 OCHzCOCl 4- Dyridine 49.00 7.52 49.21 7.52 H O C H ~ C H ~ O C H ~ C H ~ O C H ~ C H ~ O 57H CHaOCHzCOCI pyridine Furnished by Carbide and Carbon Chemicals Corporation
1.156
....
180-184 (20 mm.)
CoHieOe
49.09
7.27 49.21
1.12
....
136-140 (18 mm.)
C6Hl404
55.17
8.05 55.11
80-85 (2 mm.)
CsHizOzClz
1.082 1.4401 116-117 (12 mm.)
CrHisOaCl
1.09
....
128-132
1.18
....
204-208 (17 mm.)
CiOHl607
1.105
....
145-149 (15 mm.)
C8Hi60s
230-234 (15 mm.)
CizHzzOs
1.173
(7 mm.)
244
9.48 52.39
+
+
+
+
+
+
+
+
+
+
+
+
HOCHzCHzCHzOH CHBOCHZCOCI 65.5 pyridine 8.03 CHz-CHz 68 I AHz CHCHzOH CHiOCHzCOCl pyridine
7.23
+
+
Butyl Cellosolve methoxyacetate Diethylene glycol diethoxyacetate Carbitol ethoxyacetate
0.979 1.4242 123-125 (15 mm.)
Ethylene glycol diethoxyacet ate Butyl Cellosolve-nbutyrate Butyl Cellosolve acetate
0.911 1.4186
220
0.933 1.4140
192
Butyl Cellosolve laurate
0.881 1.4378
188 (8 mm.)
Methyl Carbitol acetate Methyl ether of triethylene glycol acetate Cellosolve succinate
1.065 1.055 1.4320
1.127
....
210-215 (15 mm.)
1.055
....
156-1130 (15 mm.)
1.12
....
163-165 (14 mm.)
....
CsHisOs
53.16
79 (10 mm.) 253
1.078 1.4381 159-162 (5 mm.)
CoHisOr
+
+
9.14 CHsCHzCHzCHzOCHzCHz0H CHaOCHzCOCl pyridine CzHsOCHrCIZHZZOT 51.80 7.91 51.60 8,03 HOCHzCHzOCHf2HzOH COCl pyridine CioHzoOs 54.54 9.09 54.75 8.85 CH~CHzOCHzCHzOCHzC,H~OH CzHIOCHzCOCl pyridine CioHiaOs 51.32 7.69 51.82 7.83 HOCHqCHzOH CzHsOCHiCOCl pyridine CioHzoOa 63.75 10.71 62.99 10.76 CHaCHzCHzCHzOCHzCHzOH (CHICHeCHzC0)zO CaHieOs 59.96 10.07 59.34 9.85 CHaCHzCHzCHzOCHpCHzOH (CHIC0)zO CisHaaOa 71.94 12.09 71.47 12.00 ~ - C ~ H B O C H ~ C H Z O H CHa(CHz)ioCOCl Furnished by Carbide and Carbon Chemicals Corporation ClHtrO4 CgHisOs 52.40 8.80 52.09 8.79 CHsOCHzCHzOCHzCHzOCHzCHzOH+ (CHsC0)zO 54.93 8.46 54.35 8.33 CHaCHzOCHzCHzOH CHz-CO CinHzzOa 56.80
9.54 56.34
+
+
+
+
+
+
+
+ +
42 70 70 54
.. ..
+
+
12
.. 72
CHa-C Benzyl Cellosolve acetate 1.076 Tetrahydrofurfuryl Cellosolve acetate
. ...
1 .062 1.4453
122-125 (5 mm.) 112 (6 mm.)
CiiHirOa
68.04
7.21 67.74
CoHieOd
57.41
8.57 57.44
7.24 CsHsCHzOCHzCHzOH pyridine 8.50 CHz-GH2
+ CHiCOCl +
97 a
+
C H ~H-CH~OCH~CH~OH (CHsC0)zO
.. . .
Carbitol levulinate
1.077
a,?-Glycerol dichlorohydrin adipate Di-8-chloroethyl phthalate
1.32
1.4887 235-240 (8 mm.)
175-182 (14 mm.)
1.31
1.5321
198 (5 mm.)
CIIHZOOS CizHisOaClr
56.89 39.13
C1zHiz04Clz 49.49
\cf CHsCHzOCHzCHzOCHzCHzOH + CHI-
8.62 55.58
8.40
4.93
COCHzCHzCOnH 4.93 ClCHzCHOHCHzCl CHzCHzCOCI 4.23
39.38
4.14 49.82
020
34.5 + HCl + CICOCHzCHz- .. 36
+ HOCHrCHzCl + HC1
+ +
..
Di-n-butyl dichloro5.81 53.01 5.54 Technical dichloro hthalic acid n1.22 1.5156 200-210 (7 mm.) CieHzoOLXz 55.33 phthalate C ~ H P O H HIS& Benzenesulfonyl-n1.15 1.5593 190-200 (6 mm.) CIBHIBOZNS 4.84%11.07% 5.28 11.37 CeHaNH-n-CrHs CoHsSOzCl Na- 33 butylaniline (27' C.) N S OH a The monotetrahydrofurfuryl ether of ethylene glycol (b. p., 105' C. a t 6 mm.; nko, 1.4595) waa prepared from tetrahydrofurfuryl alcohol, sodium, and ethylene oxide by the procedure described by Cretcher and Pittenger for similar compounds [ J . A m . Chem. Soc., 46, 1503 (1924)l.
+
+
INDUSTRIAL AND ENGINEERING CHEMISTRY
MAY, 1937
equilibrium between the gaseous refrigerant and solution is obtained a t a pressure corresponding to the vapor pressure of the refrigerant a t 4.4’C. The solution is weighed, and the solubility is expressed as grams of solute per cubic centimeter of solvent. In seeking the best combination of refrigerant and solvent, much of the early work was done on methyl chloride; then dichlorornonofluoromethane was found to have distinctly better properties for the purpose a t hand, and it was extensively studied. Later the work was extended to obtain data on a few representative solvents with other compounds which have received attention as refrigerants. Many of the solvents reported in Tables I to IV are com-
551
pounds which have not previously been described in the literature. The physical properties and analyses of the new compounds used in this work are collected in Table V. Work is in progress to establish a theory explaining the solubility characteristics of halogenated hydrocarbons in different types of solvents, and the results of this work will be submitted a t a later date. Articles covering the engineering phases of this development will appear in current issues of the air-conditioning journals, Heating, Piping, and Air Conditioning,and Refrigeration Engineering. RECEIVED December 19, 1936.
Hydrocarbon Reactions and Knock HE present paper contains an application of the authors’ theory of hydrocarbon combustion to problems of the internal combustion engine. It will be helpful to summarize the e s s e n t i a l features of the theory, but the reader is referred to the original paper for the supporting evidence and the reasoning (24).
T
Outline of Theory and Fundamental Facts The oxidation of hydrocarbons consists of two main chain reactions, one by which the hydrocarbon is transformed to aldehyde and another by which the aldehyde is oxidized to the ultimate productir carbon monoxide and water. Jn a h e a t e d vessel the chains are initiated a t the wall by the formation of monovalent radicals that carry on the chains, The primary reaction preceding the development of chains consists of the formation of minute amounts of aldehyde (the kind depending on the hydrocarbon) by a m e c h a n i s m that is imm a t e r i a l f o r the present purpose, but for which there is sorhe evidence that it is a s u r f a c e reaction involving the .intermediate formation of alkyl peroxide from the direct i n t e r a c t i o n of the hydrocarbon with o x y g e n.
IN THE INTERNAL COMBUSTION ENGINE GUENTHER VON ELBE Coal Research Laboratory, Carnegie Institute of Technology BERNARD LEWIS U. S. Bureau of Mines Experiment Station, Pittsburgh, Pa.
A brief summary is given of the chain mechanism of the oxidation of hydrocarbons. The combustion process in the Otto cycle engine is pictured to involve a race between combustion by a moving flame and the spontaneoug ignition of a part of the unburnt charge ahead of the flame. The latter occurs only after some time has elapsed following the establishment of ignition conditions in the unburnt charge. In normal combustion the flame travel is completed before the ignition lag is terminated. In knocking combustion the reverse is true. The various factors that determine the rate of flame travel and ignition lag are discussed. Numerous experimental facts, both chemical and physical, are interpreted. These include the action of antiknock agents.
Once aldehyde is formed, it may be oxidized a t the surface t o p e r a c i d that dissociates into the chain carrier radicals. The chain-initiating reaction may therefore be written :
+
RCHO 0 2 surface> RCO(O0H) surface > RCOO+OH (1) The monovalent radical, OH, reacts with the hydrocarbon, giving rise to a chain. In the first place an alkyl r a d i c a l , RCHZ, is formed; this oxidizes to an alkyl peroxide radical, RCH,OO.
+ RCHs = RCHz + Hz0 (2) RCHz + = RCHZOO OH
0 2
(3)
The radical RCHzOO has a limited lifetime, after which it decomposes into aldehyde and methoxyl, CH,O; the latter is oxidized f u r t h e r with the regeneration of an OH radical which carries on the chain by reaction 2. RCHzOO = R’CHO CHI0 -!%CO HzO OH (4)
+
+
+
If, however, the peroxide radical, RCH,OO, meets an aldehyde molecule within its lifetime, it p o s s e s s e s the
