INDUSTRIAL AND ENGINEERING CHEMISTRY
October, 1946
LITERATURE CITED
(1) Bichowsky. F. R., and Rossini, F. D., "Thermochemistry of
the Chemical Substances", New York, Reinhold Pub. Corp.. 1936.
(2) Clark, L. M., and Price, L. S., J . Soc. Chem. Ind., 52, 3 5 T (1933). (3) Giauque, TT'. F.. and Archibald, R. C., J . Am. Chem. Soc.. 59, 561 (1937). (4) Harned, H. S., and Hamer. K. J . , Ibid., 55, 2194 (1933). (6) Hoover, C. P., J . Am. Water Works Assoc., 34, 1425 (1942). (6) International Critical Tables, Vol. VI, p. 152, New York, McGraw-Hill Book Co., Inc., 1929. (7) Xapustinsky, A. F., J . Gen. Chem. (U.S.S.R.), 12, 186 (1942). (8) Langelier, K. F., J . Am. Wate? F o r k s Assoc., 28, 1500 (1936). (9) Ibid., 38, 169 (1946). (10) Ibid., 38, 179 (1946). (11) Larson, T. E., and Buswell, A. XI,, ISD. E m . CHEJI.,32, 130 (1940). (12) Larson, T. E., and Buswell, A. M., J . Am. Water Works Assoc., 34, 1067 (1942).
(13) Latimer, W.&I.,Pitzer, K. Soc., 60, 1820 (1938).
1061
S.,and Smith, W. V., J . Am. Chem.
(14) Ludwig, E. E., and Johnson, C. R., IND. ENQ. CHEM.,ANAL. ED.,14, 895 (1942). (15) Manning, G. H., private communication, 1943. (16) Pitser, K. S.,J . Am. Chem. Soc., 59, 2365 (1937). (17) Powell, S.T., Bacon, H. E., and Lill, J. R., IND. ENQ.CHEIM., 37, 842 (1945). (18) Rossini, F. D., J . Research Natl. B u r . Standards, 22, 407 (1939). (19) Ryrnar, J. K , , J . Am. Water Works Assoc., 36, 472 (1944). (20) Shomate, C. H., and Huffman, E. H., J. Am. Chem. SOC.,65, 1625 (1943). (21) Stephenson, C . C., Ibid., 68, 721 (1946). ( 2 2 ) Travers, -4., and Xouvel, Compt. rend., 188, 499 (1929). (23) Khite, C. M., J . Am. Chem. Soc., 58, 1615 (1936) PREBENTED before the Division of w a t e r . Sewage, and Sanitation Chemistry CHEJfICAL SOCIETY, Atlantic City, a t the 109th Meeting of the AMERICAN N. J.
Vapor Pressure and Vapor-Liquid Equilibria in the System Furfural- 2-methyl furan J
R. F. HOLDREN AND R. 81. HIXON Zowa S t a t e College, Ames, Zoma
T
HE catalytic reduction of furfural to Z-methylfuran has
been studied in this laboratory ( 1 ) . During the course of the research, information was necessary regarding the vapor pressures and vapor-liquid equilibria of the system. This paper reports vapor pressure measurements a t Z O O , 25', and 30" C., and vapor-liquid equilibria a t 738 mm.
Figure 1. Rlodified Apparatus of Smith and Rlenzies for Vapor Pressure Determination
The furfural used for the determinations was the middle fraction obtained from the technical product by distillation under reduced pressure. The methylfuran prepared in the catalytic studies was dried over sodium-and then distilled through a short column. The materials had the following constants: Boiling point, C. (mm.) Density. d?' Rsfractivelndex, ng
Furfural 63-65 (25) 1.160 1.5268
Methylfuran 61-63 (738) 0.915 1.4338
A modified form of the apparatus of Smith and Meneies ( 4 ) was used to determine vapor pressures (Figure 1). This a p paratus was selected because it gave reasonably accurate results with a minimum time. As a check on the apparatus, the vapor pressure of water was determined a t 25' C. 'I'he measurements were within 170of the accepted value. The vapor pressures of pure methylfuran are recorded in Table I. The data OD the total vapor pressures of furfural-methylfuran solut,ions are given in Table 11. Since furfural is rehtively nonvolatile, its partial pressure over these solutions can be calculated by means of Raoult's law with sufficient accuracy for engineering purposes. The capacities of A and B (Figure 1) were 50 and 25 cc., respectively. For determination of vapor pressures, bulb A wa8 three fourths filled with glycol; then a 10-cc. sample of a furfuralmethylfuran solution was introduced into B. After the side arm on B had been closed with a rubber tube and clamp, the apparatus was immersed in a constant temperature bath. A pump and.manometer were connected to tube C, and the pressure was lowered to a point just below the vapor pressure of the solution in B. After complete expulsion of air from B, the pressure in A was slorvly raised to the point whcre bubbles just stopped issuing from the capillary. The mrinometcr was read, the pressure lowcred about 10 mm., and the vapor pressure determined again. Successive determinations were made until measurements checked within 1 mm.; the last determined value, was taken as the vapor pressure. Air was then admitted to A
TABLE 1.
F'APOR PRESSURE OF P U R E 2-METHYLFURAN
Temperature O
F.
86.0 78.0 77.0 68.0 59.0
a
c.
30.0 25.6 25.0 20.0 15.0
Pressure, hlrn. Hg 216 179 174 139 110.5
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
1062
TABLE 11.
Vol. 38, No. 10
V A P O i i PRESSURES OF ~~XFI~1L.4L-~~ETIIYI~b'lrHAN
SOLCTIOSS 68 0' F. (20 O 0 C.)
lmeter
n',"
1.5192 1,3140
0 0.09" 0 . IXi
I 5018 1.4945 1.4921 1.4886 1,4829 1.4771 1 ,4686
0.236 0.293 0.372 0.398 0.436 0.492 0.55,o 0.640 0.752
I.Sow
1 .456!1
I.Si0S 1 5165 1.,5113
1.5053 1.5008 1.4985 1.4950 i.4~110
1.4880
U
Figure 2.
Apparatus of Othmer
for Determination of Vapor-Liquid
Equilibria
U
and the clamp on the side arm of B vias quickly opened to prevent, the liquid from surging through the bulb between A and B. A sample was taken from B by means of a capillary pipet, and the composition determined by refractive index. A small amount of methylfuran or furfural was added to B arid another determination made in the described manner. ii correction for immersion of the capillary v a s made according to the method of Smith and Menzies. The apparatus (Figure 2) used t o determine vapor-liquid equilibria mas essentially that of Othmer ( 3 ) . The liquid (250 cc. j was boiled in flask A (500-cc. capacity) until vapors emerged a t stopcock B. After the stopcock had been closctl, the vapors passed up the inner tube into condenser C, from which the liquid collected in receiver D (10-cc. capacity). The boiling vias continued until a steady temperature state m - : ~maint:iined for. 20-30 minutes. I n this may four or more complete changcs of tlie liquid in D were assured. I t was assumed that thij vias sufficient t o establish equilibrium between the liquid and vapor. A small sample of the liquid W R S drawn off a t E into 3 flmk immersed in 3 dry ice-acetone bath. Simultnneously rcwiver D was drained into a test tube. The vapor-liquid compositicJns were determined from the refract,ive index curve (Table 111). The data obtained in this manner are recorded in Table IY. Duplicate runs gave values which checked within the range (Jf 0.003 mole of methylfuran. No change in refractive index of the fiirfural-metliylfuran sulutions was observed when the solutions were boiled at atmospheric pressure for 1 hour. This check wns made because of the
illethylfuran. mole fraction
Idd.'0 62.40 80.50 55.60 a . 80 5.80 35.70 5.80 5 80 5 . 80 22.55 13.23 5.92
...
78 0" F. (25.6' C . )
Vapor pressurs, mm. H g
nao
3
26 39 56 65 76 80
1 .i 2 1 Z
1.5190 1.5155 1.5100 1,5028 1 ,4890 1.4764 1.4665
80 91 98
1.4518
I06 117
n
I 4440 1.4400
5 35
U.07C
0 128
1.4852
30.5 70 86 101
0.187 0.251 0.30~
113 1lY
0,361
0.367 0.409 0 141
123 130
1.4794 1.4719 I . 4700 1,4675 1.4640 1 4630 1.4550 1.4450 1 . 4395
....
...
Liquid RIethylfuran, mole fraction
c.
1,
I,
a .i
146.-,0
Z!11,
1.4780 1 4900
80 92
1 4962 1 .,YO71 1 .a160 1 ..jILcl
1.2210
0.662 0 542 0.420
n. 350 0.234 0 134 0 097 0.074
VaDor pressure, mm. Hg 4 23 31 46 61 8 ij
109
128 141
137 I(,(, 17 I
13i 148 16Y
160 165.5 172..i 172 183 197 210
....
1.5268
0.100
1,5190 1.5009 1.4921 1.4825 1 4800 1.4772 I . 4728
0,300 0.400 0.500 0.525 0.550 0.600 0.625 0.635 0,675 0.700 0.800 0.!)no
5.47 6.06 4 5 .75 8.26 9.43 10.30 45.75 45.7.5 4 5 . 75
0.100
202 280 431 562 663 815 896 938
0.605 0.625 0.6nl 0 . G88 0 698 0.782 0.886 0.943
4.7.75
0 . m IJ. 200
070 098 140
0.460 0.531
9.16 22.90 45.75
0.400 0 3i5 0.34.5 0.323
2 /I
0 0 0 0 0 0 0 0 0 0 0 0
...
1 .OO 0.900 0 . 700 0.tion 0 300 0 475 0.450
n.r,,Il.,
3Iethylfuran. mole fraction
1.4698
1.4670 1 46.50 I ,4628 1.4333 1.4440
1.000
1.1340
Vapor _______ MethylI1
'D"
1 . 135.5 1.4360 1,4370 1.4381
1.1418 1 4491 1 .4B79
1.4680
furan, mole fr:iction
n
988 0.980 0.970 0.SBR 0.919
n. 844
0.732 0 ti48
change i n the furfural-furfuryl a l c o h l system noted by Ilunlop and Trimhle ( 2 ) . ACKNOWLEDGMENT
This work \.vas supported in part by grants from 'I'he Quaker Oats Company and the Industrial Science Research Institute of Iowa Stnte College. LITERATURE CITED
(1) Burnette, Iowa State Coll. J . Sci., 19, 9 (1944). (2) Dunlop and Trimble, IND.ENG.CHEN.,32, 1000 (1940). ( 3 ) Othmer, Ibid., 35, G14 (1943). (4) Srnith and Rlenaies, J. Am. Chem. SOC.,32, 1448 (1910).
