INDUSTRIAL AND ENGINEERING CHEMISTRY
?6
dye without decomposition. An annular space surrounded the dye reservoir; this was open t o the hot gases from the fuel block and aided in melting the dye uniformly prior to feeding it as a liquid t o the Venturi throat. DISCUSSION
The principles involved in these developments and just outlined have peacetime applications. Information on the design. factors which influence atomization, the drop size spectrum from atomizers of differing design, the distribution of liquid droplets in a gas stream, the relative velocity of drops to gas, and the aotual energy consumed in the atomization was found t o be almost totally lacking at the time these developments were made. The designs were therefore worked out empirically with the guidance of the general principles stated here. Near the end of the war a fundamental study was started on the atomization of liquids (4) in high velocity gas streams. The results of this study are reported in the preceding paper.
to these developments. A few of these will he mentioned. H. F. Johnstone, director of the N.D.R.C. Munitions Development Laboratory, suggested the application to the airplane exhaust generator and colored smoke signal. M. F. Nathan, R. W. Davis, M. H. Raila, D. G. Edwards, E. H. Conroy, and M. J. Goglia assisted in the developments. J. A. Peck, E. C. Manthei, and R. Koehnemann made the designs for production. R. W. Parry directed the development of suitable pyrotechnic fuels. LITERATURE CITED (1)
Johnstone, H. F., and Goglia, M. J., O.S.R.D. Rept. 5488, O.T.S. Rept. PB 15639 (Aug. 25, 1945); Biblio. Sci. Ind. Repts., 1,
(2)
Johnstone, H. F., Kallal, R. J., and Adams, C. H., O.S.R.D. Rept. 5309, O.T.S. Rept. PB 15638 (July 5, 1945); Biblio.
(3)
LeTourneau, R. L., Rice, R. I., Hrubecky, H. F., and Johnstone, H. F., O.S.R.D. Rept. 6301, O.T.S. Rept. PB 20836 (Nov. 1945); Biblio. Sci. Ind. Repts., 2, 313 (1946). Lewis, H. C., Edwards, D. G., Goglia, M. J., Rice, R. I., and Smith, L. W., O.S.R.D. Rept. 6345, O.T.S. Rept. PB 20837 (Nov. 23, 1945); Biblio.Sci. Ind.Repts., 2, 79 (1946). Nathan, M . F., Davis, R. W., Manthei, E. C., and Comings, E.’ W., O.S.R.D. Rept. 6428, O.T.S. Rept. 32210 (Dec. 29, 1945); Biblio.Sci. Ind. Repts., 2, 660 (1946). Rice, R. I., O.S.R.D. Rept. 6344, O.T.S. Rept. PB 32212 (Nov.
1136 (1946).
Sci. Ind. R e p t s . , 1, 1061 (1946).
(4)
ACKNOWLEDGMENT
This paper is based on work done for the office of Scientific Research and Development under Contract OEMsr-102 with the University of Illinois as a result of directives from the Chemical Warfare Service and the Navy Bureau of Ordnance. 9 number of persons in addition to the authors contributed considerably
Vol. 40, No. 1
(5)
(6)
23, 1945); Biblio.
Sci. Ind. Repts., 2, 859 (1946).
RBCEIYED Spril 12, 1947.
Multistage Ion-Exchange System for the Fractionation of Solutes Radium-Barium Fractionation ALLEN F. REID’ Columbia University, New Y o r k , N . Y .
A method is outlined for utilization of selective adsorption capacities of ion-exchange substances in a reflux multistage system. The operation of a pilot plant for the concentration of radium in a radium-barium mixture by this method is described.
T
H E selective capacity of ion-exchange substances for different solutes is fairly well known, and the fact that selectivity has been demonstrated in the concentration of the isotopes of lithium and potassium (1, 3, 4) illustrates the broad scope of its application. However, where that selectivity must be applied repeatedly t o obtain a certain degree of refinement of separated products, the process used entails a series of consecutive batch operations, and, as such, is limited in convenience of quantity operation. The method advanced here utilizes the above-mentioned selectivity in a reflux multistage system which may be adapted to continuous operation. Since there exists some uncertainty in the mechanisms of ion exchange, “absorb” is used below to indicate the uptake of the described ions with the release of any displaced ions.
cell, and regeneration of the cell by the acidified output solution of a previous cell. These two steps make up a cycle which is repeated over and over in every cell to accommodate the advancing solution. With proper direction of the solution through a bank of cells and suitable conditioning of the solution in its passage, countercurrent progression of the separated fractions is continuous from the charge point to the final withdrawal points on the system. Thus the system is analogous to a rectifying column. The example outlined below is based on the use of a cationexchanger with hydrogen ions as convenient, regenerating ions, but the method may be employed with any type of ion-exchanger with any suitable ion for regeneration. I n the subsequent discussion concentrations of forms of the ion-exchanger, indicated by HZ, A Z , and BZ, are given in moles available for exchange per bulk liter of the ion-exchange material. This arbitrary choice ’cvas made for its convenience as well as for its similarity to conventional concentration units. Given A + and B + as two cations to be separated. If HZ is the acid form of the exchanger,
METHOD
+ HZ = H + + A 2 B + + HZ = H f + BZ
Broadly, the method includes: selective absorption of a portion of the ions in a through-going solution by an exchange 1 Present address, Southwestern Medical College, Dallas, Tex.
If. a t anv time when a solution of A + and B f is oassina: [AZI -, separation is possible. through the ion-exchanger, [B-I [BZI
A+
*
(1) (2) I
INDUSTRIAL A N D ENGINEERING CHEMISTRY
January 1948
Figure 1.
Flow Diagram Showing Progressive Staging of Unit Absorbers R. Reservoir 2. Ion-exchange cell M . Acidifier N. Deacidifier .
A schematic diagram of a system for compounding the simple fractionation is shown in Figure 1. The system is valved so that the flow of solutions alternates [A21 tB+l between the double and single lines. Thus if
[ B Z ][A+]
following the double line, the material in Rz goes through one fractionation stage, leaving in Z1material richer in A and in Rsmaterial richer in B. Following the single line the material in R3 is acidified and collects much of the A-enriched material from Z 3 (not shown). This solution then passes through a system in which the acidity is reduced so that the two solutes may experience selective absorption in Zz. In this manner, A-enriched material is constantly being moved up and B-enriched material down with progressive separation. The concentrates may be drawn off at suitable points and supply furnished a t a central position of a bank of cells with the arrangement necessary to a suitable material balance. Normally, the ideal arrangement would entail the exchanger’s absorbing about half the ions t o be separated on the first step (double lines) and releasing them all on the succeeding step (single lines), giving maximum throughput. EXPERIMENTAL
The separation of radium and barium by the method described was tried. The ion-exchange resin used was ZeoKarb H furnished by the Permutit Company, New York, N. Y. Investigation of the distribution of barium between solution and resin resulting after passing solutions of various concentrations of hydrochloric acid and barium chloride through a sample of the resin showed the reaction to be effectively 2Ba1/2 2
+ 2Hf
= 2HZ
+ Ba++
(3)
over a considerable range of concentrations, with (Table I)
(4) where [BallzZ]
+ [HZ] = 0.55
(5)
[Bal/2Z1 and [ HZ] indicating the respective concentrations in
77
moles per liter of ZeoKarb H. The solution was passed a t a rate of 48 cc. per minute through a cylinder of the resin 7.5 cm. high and 2.3 cm. in diameter, and equilibrium concentrations were closely approached in the first passage. Samples of the solutions were evaporated t o dryness, the solute was redissolved, and barium analyses were made by the use of simple conductivity measurements. Using the behavior of the tested samples as a guide for process design, it was decided t o erect a fractionating system conforming t o the specifications of Figure 2. Five cells, each containing 2.1 cc. of ZeoKarb H, were set up. A solution of radipm and barium chlorides was made 0.13 molar in hydrochloric acid (solution X). A solution 2.0 molar in hydrochloric acid was used for regenerations. For simplicity, “deacidification” was accomplished by evaporation to dryness and subsequent solution of the residue in 0.13 molar hydrochloric acid. In commercial operation various acid-absorbers might be of practical value for this deacidification step. To start operation, a 25-cc. sample of solution X was first poured through each cell a t a uniform rate, requiring 30 seconds for the passage. As subsequent analysis showed, the portion of the solute mixture absorbed (about 43%) contained a higher ratio of radium to barium than that passing through. As diagrammed in Figure 2, the throughput portions were then acidified and passed through succeeding cells (dotted lines) collecting most of the previously absorbed solute. The solutions were then deacidified so that selective absorption could again take place on the next passage (solid lines); and the process was continued progressively. After six absorption-regeneration cycles it was assumed that a steady state was nearly reached, and operation was discontinued. A 25-cc. sample of 2 N hydrochloric acid was then flushed through A and the effluent solution analyzed with the other samples listed in Table 11. The barium analyses, as in the previous samples, were made by conductivity measurements; the radium analyses were made by y-ray counting-the overall probable error was about 3%. As may be noticed in Table 11, the metallic ion throughput became less and less toward the end of the series; this was due t o greater a b s o r p tion than was anticipated in the cells. A calculation of the expected [&++I for the analyzed [Ba + + ] in each solution was made for different values of a. As can be U seen from Table Figure 2. Fractionating System 11, a value of a = 1.22 gave A-E. Cells of 2.1 CC. of ZeoKarb each S. Reservoir of 2.00 molar HCI good agreement X. Reservoir of solution HC1, 0.130 molar with experiBaCln. 0.046 molar mental results. RaCh, 0.104 X 10-0 molar
-
INDUSTRIAL AND ENGINEERING CHEMISTRY
78
OF RADIVM A X D BARIUM TABLE I. SEPARATION Experiment [H +I [Ba + I [Bai/?Z] K +
0,086 0.255 0,423 0.507 0.755 1.23 2.01 2.30 0.140
6 . 8 X 10-4 23.7 38.8 46.2 50.6 56.3 66.6 62.0 200.
0.119 0.0966 0.0766 0.0640 0.0546 0,0332 0.0256 0.0238 0.294
1.20 0.80 0.83 1.04 0.73 0.90 0.69 m.57 0.77 Av. 0 . 8 4
TABLE 11. FRACTIONATIOX ,-
Vol. 40, No. 1
If practical operation were carried out with a equal to 1.22, the radium-barium ratio of a solution could be increased from 2 x 10-6 to 100 with less than 200 cells, and an additional stripping section of 100 cells would save all but O.Olyoof the radium. (Khen the fractional crystallization method is used, the ratio is normally brought from about 2 X 10-8 to > 9 with somewhat more radium discarded, 2 . ) 1 5 t h a 5-unit cascade of cells ranging in size from 30 liters t o 5 cc. and totaling 1000 liters, such a plant could probably handle 200 grams of radium per month, or more than the world prewar annual radium production. Possibly a combination of the ion-exchange method for lower radium concentrations with a fractional crystallization method for the higher concentrations would be practical for radium refining. With an ion-exchanger having = 1.022, equivalent to Taylor and Urey's value (S), a five fold increase in concentration of Li6 could probably be obtained with as few as 200 cells, using a system similar to the radium-barium system. The use of the method for similar operations with ion-exchange substances is clearly feasible. The recycle method could be used for fractionation by using other specific absorbers and various methods of regeneration. ' (Y
1 6 6 6 6 6 6
E reject E reject
d C
b
a
A flush
0.0263 0.0304 0.0168 0.00972 0.00667 0.00284 0,00334
0.88
1.oo
1.12 1.24 1.45 1.40 1.54
0.91 0.97 1.16
1.29 1.34 1.40 1.54
LITERATURE CITED
EXTENSIONS O F METHOD
Since optimally the effluent solution of any cell, j ; has the same relative concentration of solutes as are absorbed in cell j 2, theoretically the change in ratio obtainable in a bank of rn cells would be
+
(1) Dean, J. G., U. S. Patent 2,204,072 (1940). (2) Kuebel, il.,J . Chem. Education, 17, 417 (1940). (3) Taylor, T. I., and Utey, H. C., J . Chem. Phys., 5 , 597 (1937). (4)Ibid., 6, 429 (1938). RECEIVEDJuly 16, 1946.
POLYMERIZATION OF P NTENES V. N. IPATIEFF AND R. E. SCHAAD Universal Oil Products C o m p a n y , Chicugo, I l l .
3-Methyl-1-butene and a mixture of Z-methyl-l-buteneand 2-methyl-2-butene were polymerized to decenes in the presence of solid phosphoric acid catalyst ( I , 3, 4) at 83" C. and 100" 6 . Catalytic hydrogenation converted these decenes into decane fractions with 94.6 octane number (Rfotor method). During the polymerization of 3-methyl1-butene a t 83' and 100" C., 8970 of the 3-methyl-1-butene charged was isomerized into higher boiling pentenes, mainly 2-methyl-2-butene.
HE apparatus was essentially the same as used previously in polymerization of propene and butenes. The pentene under the desired nitrogen pressure was passed through 5-mm. copper tubing to the steel tube (14-mm. inside diameter) containing 60 cc. of 4-10 mesh crushed solid phosphoric acid polymerization catalyst, heated in a n aluminum bronze block furnace equipped with a thermoregulator. The catalyst (51.5 grams) was held in place in the catalyst tube by plugs of steel wool so that it occupied the central 40-em. section of the 60-em. heated part of the tube, which declined about 15" from the horizontal towarti its exit end. From the exit end of the catalyst tube, polymers and pentene were released continuously through a needle valve and short copper tube to a water-cooled Pyrex receiver, the top of which was connected by rubber tubing to a trap cooled by dry ice and acetone, in order to collect low boiling materials that escaped from the receiver. The products were then distilled in order to determine how much polymerization had taken place. The unconverted pentene separated from the polymers of 3-methyl-1-butene was also
subjected to Podbielniak low temperature distillation to separate 3-methyl-1-butenef rom its isomerization product. *Properties were determined on the polymers before and after hydrogenation. POLYMERIZATIONS
2-METHYL-l-BUTENE AND 2-bIETHYL-2-BUTENE. Polymerizations were made on a mixture (boiling point, 30-38" C.) of 757, 2-methyl-1-butene and 25% 2-methyl-2-butene obtained by dehydrating tert-amyl alcohol over alumina a t 427' C. As Table I shows, this mixture of 2-methyl-1-butene and 2methyl-2-butene underwent 70-78% polymerization a t 85 ' C. (186 F.) at 7.4-8.5 kg. per square em. (105-1 19 pounds per square inch) pressure. Hydrogenation of the polymers by heating in a n Ipatieff rotating autoclave for 6 hours at 225 O C. in the presence of 10% by weight of black nickel oxide and a t 100 kg. per square em. (1420 pounds per square inch gage) initial hydrogen pressure, gave a saturated product; the 140-160" C. fraction, which was 88% by volume of the product, had 94.6 octane number (Motor method). The results of a high temperature Podbielniak distillation of the polymer fraction are given in Figure 1. %METHYL-l-BUTENE, prepared by dehydrating isoamyl alcohol o;er alumina at 427" C., was freed from 2-methyl-1-butene and 2-methyl-2-butene by washing with 70y0 sulfuric acid until the hydrocarbon underwent no further shrinkage in volume (3 to 4 washings). Then it was washed with water, caustic, and water, and dried over calcium chloride. The fraction of this pentene boiling from 21 ' to 22.5' C. was charged in these polymerization tests. Comparison of the data of Table I1 with those of Table I MIXTURE O F
O
