November, 1942
INDUSTRIAL AND ENGINEERING CHEMISTRY
benzene, but likewise by increasing quantities of petroleum cresylic acids. It is of interest to note that in 1941 the plastics industry consumed intermediates which required as raw materials some 700 million cubic feet of natural gas for methane, 2.9 billion cubic feet of propane for ethylene, 270 million cubic feet of propane-butane mixtures, 70 million cubic feet of propylene, and 150,000barrels of petroleum. The quantities soon to be required for synthetic rubber will make most of these amounts fade into insignificance. Nor should the coal industry expect competition from only one quarter. Agricultural products may be expected to play an increasingly important role in the plastics industry of tomorrow. Brazil is keen about a large program for the production of plastics from coffee. Soybean resins have already entered the field. Patents appear in great numbers for the production of plastics from cottonseed hulls, corn proteins, and bagasse. In the synthetic rubber picture, butadiene from alcohol and other agricultural products is now a certainty. Waste sulfite liquors and exploded wood
1391
chips are constantly contributing larger volumes of lignin plastics. Similarly, the plastics industry may expect to see a continued use of products derived from the naval stores industry. The coal industry need not necessarily suffer from this competition, even though prices will undoubtedly resume their downward trend after the war and the markets for some intermediates may be lost. The prospects for a tremendous increase in the volume of plastics production will render the future for coal derivatives extremely bright if every effort is made to maintain research, reduce basic costs of manufacture, increase yields, and produce a varied and flexible number of intermediates. Research must continue to be the watchword of the day! PEEBI~NTED as part of the Symposium on Uses of Coal by Various Industries before the Division of Gas and Fuel Chemistry at the 104th Meeting of the AMIH~RICAN CHEMICAL SOCIETY. Buffalo, N. Y . Joint oontribution from the Pittsburgh Equitable Meter Company's Industrial Fellowship at Mellon Institute and the Chemical Engineering Laboratory of the Gulf Research and Development Company.
CALCIUM CHLORIDE NOMOGRAPHS D. S . DAVIS Michigan Alkali Company, Wyandotte, Mich. ALCIUM chloride, available in large quantities in flake form, finds industrial application as a general dehydrating agent, in the drying of gases, in the manufacture of liquid carbon dioxide, ammonia, and air, in the curing of portland cement concrete, in fireproofing paints, in the manufacture of gunpowder, dry colors, and lakes, in automatic sprinkler solutions, and as a refrigerating brine. It is admirably adapted to the latter use since the specific heats of its aqueous solutions are high enough to ensure the use of moderately small quantities of brine, accidental ammonia leakage does it no harm, it is not particularly corrosive, and its solutions have satisfactorily low freezing points. Large amounts of calcium chloride are used in road treatment for stabilization and dust laying, for ice control on highways, and for the treatment of coal and coke for dustproofing and freezeproofing. Since many of the uses of calcium chloride require brines, hydrometric methods of analysis for control purposes offer obvious advantages. Excellent specific gravity-temperatureconcentration data (1, 3, 4) are available, but these are in tabular form and require inconvenient interpolation. For temperatures between 10' and 30' C. the I. C. T. data (4) can be represented closely by the equations,
C
for c = 6 to 20 s = a + + + p 0.736 )
for c
= 20 to
34
where 6 = specific gravity, 60/60" F. c = concentration of anhydrous CaCll in pure aqueous solutions, a, b = functions of tern erature resulting from Lagrange interpolation (%f and defined by Table I Commercial calcium chloride contains about 1.5 per cent of sodium chloride and thus necessitates adjustment of the quantity e to cover concentrations of anhydrous calcium
chloride in the impure brines using the Dow data (3). The nomographs, based on this correlation, extend the utility of the hydrometric method by permitting reliable graphical interpolations to be made quickly and conveniently. The use of the charts is illustrated as follows: What is the concentration of calcium chloride in a commercial brine when
TABLEI. FUNCTIONS OF TEMPERATURE Temp.,
c.
10 12 14 16 18
a0
22 24 26 28 30
o
a 0 * 9880 0.9878 0.9875 0.9872 0.9869 0,9865 0,9861 0.9857 0.9852 0.9848 0.9842
-
6 t o 20
b
0,009723 0.009690 0.009659 0.009604 0.009632 0.009578 0.009554 0.009529 0,009506 0.009484 0.009465
c = 20 to 34 a b 0.9619 0.010880 0.010851 0.9616 0.9613 0.010826 0.010804 0.9609 0.010783 0.9605 0,9600 0.010765 0.010750 0.9594 0.9588 0.010730 0.010724 0.9581 0.9574 0.010716 0.9565 0.010706
TABLE11. AGREEMENTBETWEEN TABULAR AND CHART DATA Hydrometer Reading
Temp.,
1.071 1.127 1,177 1.231 1.286 1.331 1.068 1,123 1.173 1.226 1,280 1.325 1.060 1.122 1.171 1.223 1,278 1.322
10 10 10 10 10 10 21.1 21.1 21.1 21.1 21.1 21.1 26.7 26.7 26.7 26.7 26.7 26.7
c.
70
CaClt
Nomograph
CaClz Assoc.
8.15 14.05 19.1 24.15 29.1 33.1 8.18 14.35 19.2 24.15 29.1 33.12 8.15 14.4 19.2 24.1 29.2 33.2
8.0 14.0 19.0 24.0 29.0 33.0 8.0 14.0 19.0 24.0 29.0 33.0 8.0 14.0 19.0 24.0 29.0 33.0
Vol. 34, No. 11
INDUSTRIAL A N D ENGINEERING CHEMISTRY
1394
the hydrometer reading is 1.130 a t 22' C.? Using Figure 1, connect 22 on the temperature with 1.130 on the hydrometer reading scale and read the concentration as 14.8 per cent calcium chloride. What is the freezing point of such a solution? Opposite 14.8 per cent calcium chloride, read the freezing point as 13.9" F. What is the concentration of calcium chloride in a refrigerating brine when the hydrometer reading is 1.248 at 17" C.? Using Figure 2, connect 17 on the temperature scale with 1.248 on the hydrometer reading scale and read the concentration of calcium chloride as 26.0 per cent.
Hydrometer
Reading
E-" FIGURE 1
fer Cent Freezing talcfun Chforiae A,.*F
Ii
20
0
5
io
Ternperdure, 'c.
14
15
12
20
8125
/fydrorneler
Rea dinj Freezing Pt: e,?
27
Per Cent Calcium Chloride -34
0-
-32
-20-
F30
-40-
- -30 -
-60-
-40-
-30-
-28
-26
-20
-24
-/o
-22
0-
- 20
FIGURE 2
The freezing point of this brine is read just opposite as -25.8" F. The line coordinate charts yield concentrations in good agreement with tabular data from an undisclosed source, given by the Calcium Chloride Association (I), as shown by Table 11.
Literature Cited (1) Calcium Chloride Assoo., Bull. 30, 17 (1942). (2) Davis, D. S., Chem. & Met. Eng., 45, 383 (1938). (3) Dow Chemical Co., private communication to Calcium Chloride Assoc. (4) International Critical Tables, Vol. 11, p. 327 (1928).
