I N D U S T R I A L ,4N D E N G I N E E R I N G C H E M I S T R Y
496
operation and be further developed to admit of continuous operation. Chemical equipment already available could doubtless be applied without further developmental experimentation. For this reason, further work in this laboratory did not seem warranted. The observations made are offered in their present form in the belief that they cover the fundamentals required for a n appraisal of the recommendations embodied here.
ECONOMIC CONSIDERATIONS No factors appear here which would indicate that the proposed conversion represents difficulties or costs exceeding those encountered in the present manufacture of hydrochloric acid from sodium chloride and sulfuric acid, or from sodium chloride and sodium acid sulfate. Accordingly, there are offered comparisons of the three methods based on current quotations ( 7 ) of the raw materials and finished products involved (Table 11). It is obvious that these quotations do not accurately express the prices at which some of these commodities are purchasable. However, they do serve to illustrate the relative values involved. Further, it is assumed that operating costs are the same in each case, although it appears that these may prove to be least in the process dealt with here. While these estimates are based on 95 per cent potassium chloride, it is assumed that the 99 per cent domestic (or imported) product would be employed, since it is purchasable a t the same price per unit of potassium oxide as the lower grades, and there would be no objective in processing a diluent having no commercial value.
TABLE11. RELATIVEVALUESIN HYDROCHLORIC ACID PRODUCTION KC1
+ HISO&:
(Basis. . . one ton hydrochloric acid)
2 02 tons 957 KC1 a t $40 50 1:73 tons 60 % X S Oa~t Sli.00
Total 2.36 tons 95% KzSOr a t $44.85 Differential Der ton HC1
+ HzSOa: 1.60 tons NaCl at $11.40
NaCl
1.73 tons 60” HzSOa a t $11.00
19.00 100.80 105.50
-4.70
18.25 19.00
Tots1
37.2.5 23.40
Differential per ton HCl NaHSO4:
13.85
1.95 tons NazSOa a t $12.00 9
$ 81.80
NaCl
+
1.60 tons NaCl at $11.40 4.32 tons NaHSOd a t $12.00
Total
18.25
51.84 -
4.33 tons NazSO4 a t $12.00
70.09 51.96
Differential per ton HC1
18.13
I n 1931 (1) thirty-one establishments within the United States produced a total of 55,000 tons anhydrous hydrochloric acid, of which only 14,000 tons were consumed where produced, the balance of 41,000 tons being sold a t a valuation of $2,422,000. As acid of commercial (20’ Be.) strength, each ton of hydrochloric acid involved 2 tons of water on which freight and handling charges were paid. There is no impressive reason why intraplant hydrochloric acid production could not be extended with the installation of units of appropriate capacities, employing such a method asis here described; this enterprise would be undertaken, however, in terms of advantageous supplies of raw materials and markets for potassium sulfate. To promote fertilizer use through the simplest expedient of reducing costs, freight charges must be maintained at the lower levels. The potassium chloride which can be intercepted for conversion enroute to the fertilizer market represents the best economic advantage. UTILIZATION OF HYDROCHLORIC ACID I n chemical plants employing hydrochloric acid as a reagent, the product thus yielded (largely in the gaseous form)
Vol. 26, No. 5
is deliverable to the process when required in this form or in any desired concentration, continuously or intermittently as wished. If it requires marketing, it should be able to enter the market a t competitive prices. However, the proposition does not depend for its merits upon already established usages for hydrochloric acid and warrants consideration quite independently of such usages since there is a potential outlet for large quantities in the manufacture of agricultural phosphates. I n this application the proposal, in essence, is that a part of the sulfuric acid now being applied to phosphate rock to yield superphosphate, should instead be applied to potassium chloride to yield the sulfate, and that the resulting hydrochloric acid should be applied to phosphate rock to yield an agronomically available phosphatic fertilizer ingredient. The calcium chloride, a byproduct in the latter, is largely removable and therefore, unlike the calcium sulfate in the former, need not remain as an unavoidable diluent. High-analysis phosphates result. The competitive disposal of hydrochloric acid is thereby avoided, and, in fact, the entire enterprise can be established and conducted without interfering with existing domestic industry. It is obvious that hydrochloric acid released from potassium chloride by sulfuric acid is equivalent to the latter and, when applied to phosphate rock, renders available an equivalent proportion of PzOs ( 2 ) . From the viewpoint of the present superphosphate manufacturer, if this were the whole story, profits would be derivable only from the price differential between potassium chloride and potassium sulfate. However, it now appears entirely feasible to recover the PzOs, made available by hydrochloric acid, as the dibasic calcium salt, if not even in the more basic form, from which it becomes apparent that the hydrochloric acid thus employed has a t least twice the efficiency of the equivalent sulfuric acid as employed in superphosphate manufacture to yield the monobasic salt. Per unit weight of sulfuric acid purchased, there is yielded accordingly the equivalent of potassium sulfate, and two equivalents of available PzOs. The details are to be presented in a subsequent contribution. LITERATURE CITED (1) Bureau of t h e Census, personal communication. (2) Fox, E. J., a n d Whittaker, C. W., IXD.ENQ.CHEM.,19, 349 (1927). (3) Frydlander, Rev. prod. chim., 27, 5 (1924); Saccharinfabrik Akt.-Ges. vorm. Fahlberg, List & Co., Geyman P a t e n t 261,411 (Oct. 20, 1911); Meyer and Klages, U. S. P a t e n t 1,099,382 (June 9, 1914); Fabrique produits chimiques T h a n n Mulhouse, British P a t e n t s 137,296 (Dee. 29, 1919), 137,519 (Dee. 30, 1919). (4) International Critical Tables, Vol. V, pp. 169 ff., McGraw-Hill, 1926. (5) Landolt, P. E., Chem. & M e t . Eng., 40, 345 (1933). (6) Madorsky, S. L., IND. ENG.CHEM.,24, 233 (1932). (7) Oil, Paint Drug Eeptr., 124, 5 6.(1933). (8) Partridge, E. P., IND.Ex+.CHEM.,24, 895 (1932); Mansfield, G. R., J . Chem. Education, 7, 737 (1930); Hill, J. R., a n d Adams, J. R., IND.EKG.CHEM.,23, 658 (1931). (9) Turrentine, J. W., “Potash,” Wiley, 1926. RECEIVED November 23, 1933. Presented before the Division of Industrial and Engineering Chemistry at the 87th .Meeting of the American Chemical Society, St. Petersburg, Fla., March 25 to 30, 934.
I n the article, “Predicting Stability of GasoCORRECTION. lines to Aging,” by Winning and Thomas, IND.ENQ.CHEM., 2 5 , 511-16 (1933), an error in statement appears at the bottom of the fist column of page 514. The sentence reading ‘ I . . .the logarithm of the stability may be plotted as a linear function of the absolute temperature. . .” should read I‘. . as a linear function of the reciprocal of absolute temperature. . .” CARLWINNINQ
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