INDUSTRIAL AND ENGINEERING CHEMISTRY
April, 1946
367
“of Standards (above 9 carbon TABLE FOR HYDROCARBONS TABLE IV. GRAVITYCONVERSION atoms in most cases) were obA.P.I. ,Gravities tained mostly from Egloff (4, 6). Olefins Olefins Olefins Olefins In the selection of values, care and and and . Alkyl and cycloPenBennaphHexnaphHeparonaphwas taken to use those on difthenes Octanes tanes rnatics anes Toluene thenes zene thenes pentane tanes Density, fcrcnt samples only where data C8 C’ c’ cB c’ C6 c’ CS CS CS CS d’: , (70)” (72) (78) (84) (86) (92) (98) (100) (106) (112) (114) by different investigators agreed .. 0.6100 98.5 .. .. .. .. or where data from different .. 0.6200 94:9 94.9 .... .. .. .. .. .. ... . .. .. .. 0.6300 91.3 91.3 sources gave the same value of 0.6400 87.8 .. .. 87:s .. .. a. This was necessary becausc .. 0.6500 84.6 .. .. 84’6 84.6 .. .. 0.6600 81.2 .. ... . 81.3 81.3 .. .. .. 78:3 . . much ’of the density data lacked .. 0.6700 78.1 .... 78.2 78.2 the necessary accuracy, and .. .. 75:3 0.6800 75.0 . . 75.1 ., 75:2 75.2 . . 72.3 .72.2 0.6900 72.0 . . . . 72.1 . . . . 72.2 cvcn an error of *0.0001 in 69.3 ,. G9:4 69.4 69.2 .. .. 69.3 0.7000 69.1 .. .. density produces an appreciable .. 66.6 66.6 66.5 66.3 . . .. 66.4 .. .. 0.7100 .. 63.8 63.9 .. 63.6 .. .. 63.7 .. . . 63.8 0.7200 error in the calculated value of a. .. 61.2 61.2 61.1 .. 61.0 .. .. 61.1 .. ,. 0.7300 58.5 *. .... 58.6 .. 58.4 .... .... 58.5 .. .. .. 0.7400 Requirements of accuracy and 56.1 .. 55.9 56.0 . . ’ 56.0 ... 0.7500 temperature range covered are .. 53.6 0.7600. .. . . . . ‘53.5 .. .. 63.6 .. .... .. 51.2 ,. 0.7700 .. .. .. 51.1 .... .. .. 51.2 more rigorous for the calculation .. 48.9 .. 0.7800 .... .. 48.8 48.8 of p than for calculation of a. .. .. 46.6 .. .. 0.7900 .. *. * * . . . . .. 44.4 . . 0.8000 . , .. .. .. .. . . . . T h e data suitable for calculation 0.8100-0.8500(no compounds) of P have already been noted. .. .. 32.1 0.8600 *. .... ,. 32.1 .. .. .. *. 30.3 .. 0.8700 ... *. 30:1 .. 30.2 .. From these, 6 was found by the *. 28.4 *. *. 0.8800 ,. 28.3 . . .. *. graphical procedure used by .. 26.6 .. 0.8900 * * .. .. .. .. 0.9000 , . *. *. .. .. .. Calingaert (1). 4 Figures in parentheses are molecular weights. Density data are available for G and lighter gaseous hydrocarbons. These were not included. to CISwas 0.565 a t temperatures near 20” C. Equation 5 is usesince the liquid density depends on pressure, and the gaseous ful in connection with Equations 1, 2, and 3 to correct refractive hydrocarbons under high pressures do not correlate well with the indices for temperature. While Equation 5 was developed from higher hydrocarbons a t atmospheric pressure. data near 20’ C., the temperature limits over which it is valid are unknown.
.
.
I
.
I
I .
..
I
. ..
....
..
....
.
..
TEMPERATURE-DENSITY-REFRACTIVE INDEX
Temperature, density, and refractive index are fundamentally rclated to molecular structure. For n-paraffins (and their mixtures) at 20’ C. the density-refractive index relation (%)is:
n = 0.52167d
+ 1.03104
(4)
Ward and Kurtz (14, 15) discussed the theoretical relations and noted that the ratio of differences of refractive index to den: sity between two temperatures was substantially constant, or
An
= CPd
I
(5)
For hcavy petroleum fractions (A.S.T.M. groups 0 and 1) the value of C was 0.59, and for all lighter petroleum oils and wax, C mas 0.60. Mibashan (9) found that C for n-paraffins from CS
.
.
- 8 _NORMAL PARAFF 0
LITERATURE CITED
(1) Calingaert, G.,Beatty, H. A., Kuder, R. C., and Thornson, G. W., IND. ENQ.CHEM.,33, 104 (1941). (2) Deanesly, R. M., and Carleton, L. T., J . Phys. Chem., 45, 1104 (1941). ( 3 ) Dornte, P. W., and Smyth, C. P., J . Am. Chem. SOC.,52, 3546 (1930). (4) Egloff, G. “Physical Constants of Hydrocarbons”, Vola. I and 11, Ned York, Reinhold Publishing Corp., 1939. (5) Egloff, G., and Grosse, A. V., U.0.P. BookEets, 217,219 (1938). (6) International Critical Tables, Vol. 111, p. 27 (1928). (7) Kelso, E. A,, and Felsing, W. A,, IND.ENQ.CHEM.,34, 161 (1942). (8) Lipkin, M.R.,and Kurtz, S. S., IND. ENQ.CHEM.,ANAL.ED., 13,291(1941). (9) Mibashan, A.,Tram. Faraday SOC.,41,34 (1945). (10) Natl. Burzof standards, “Selected VBlues of Properties of Hydrocarboqs”, A.P.I. Research Project 44 (1943). (11) Patnode, W., and Scheiber, W. J., J . Am. Chem. SOC.,61, 3449 (1939). (12) Srnyth, C. P., and Stoops, W. N., J . A m . C h e i . SOC.,50, 1883 (1928). (13) Tagliabue, C. J., Mfg. Co., Tag Manual for Inspectors of Petroleum, 26th ed., 1942. (14) Ward, A. L.,and Kurtz, 8. S., IND. ENQ.CHEM.,ANAL.ED., 10, 659 (1938). (15) Ward, A. L., and Kurtz, 9. S., in “Science of Petroleum”, Vol. 11, p. 1137,Oxford Univ. Press, 1938.
x
‘
4
6
Figure 3.
8
I x MW
IO
12
I4
103
Values of @ for n-Paraffins
16
Liquid Holdup and Flooding in Packed Towers-Correction
6
Attention is called to a n inconsistency in the units specified for the quantity ULin the table of nomenclature page 445) of this article by J. C. El in and F. B. Weiss [IND.! E h . CHEM., 31, 435 (1939)l. UL,&e superficial liquor velocity based on entire cross section, should be correctly ft./sec. rather than ft./hr. as printed. With this change the superficial mass velocity of liquor, lb./(hr.) (sq. ft.) = 3600 ULp ~ . The chart of Figure 10 as printed is correct, as long as consistcnt time units are employed.
