INDUSTRIAL A X D EiVGIiVEERISG CHEMISTRY
818
This observation led to the following series of experiments, which had for its object the determination of the influence of the alkalinity and the color-producing organic matter on the foaming tendency of the liquid as observed by a simple shaking test. Although it was understood that there was not necessarily a proportional relation between the tendency of a given water to foam when shaken in a bottle and when used in a high-pressure boiler, it was believed that the experiments might isolate the substances or conditions contributing to that film stabilization which Foulk has shown to be so intimately related to foaming. I n the first two experiments described the effect of the alkalinity was studied. I n one case about 90 per cent of the total alkalinity (to methyl orange) of the sample was neutralized with 0.5 N sulfuric acid. I n another case suficient acid was employed to make the liquid definitely acid. I n the remaining experiments the effect of suspended matter was investigated. Here the attempt was made to remove as much as possible of the suspended matter, including the colloidal organic matter which was thought might be primarily responsible for the foaming tendency. It was appreciated that this removal by ordinary methods of coagulation and filtration would probably be incomplete, owing to possible decomposition and increased peptization of the organic matter originally present in the water by reason of the high concentration of alkali and elevated boiler temperatures. Aluminum sulfate and ferric chloride were used as coagulants. The former gave poor results, as was expected, due in part a t least to the abnormal alkalinity of the liquid. Ferric chloride gave much better results. I n view of the incomplete removal by coagulation of organic matter, as evidenced by the residual color, the effect of several oxidizing agents mas tried, of which aqua regia alone gave promising results. In order to avoid confusing the effect of oxidation and of acidification, one sample that had been given the treatment with aqua regia was subsequently neutralized with sufficient sodium hydroxide to bring the pH up to approximately the original value in the boiler water. The several treatments employed are shown in the following table, and are numbered for the purpose of identification in the succeeding tabulation: TREATMENT
N'O.
1 2 3 4 5 6 7 8
Control-no treatment; p H 11 6 Xeutralization of 90 per cent of alkalinity; p H 5 2 Excess of acid; p H approximately 2 6 Aluminum sulfate, 10 grains per gallon (170 p p m ) ; PH 11 6 Ferric chloride, 10 grains per gallon (170 p p m ) , p H 11 6 Ferric chloride, 20 grains per gallon (340 p p m ) , pH 11 2 Aqua regia Neutralization of (7) with NaOH to p H 11.6
T'ol. 21, s o . 9
The treated samples, all of approximately like volume, were placed in 8-ounce (226.8-cc.) glass-stoppered bottles, shaken simultaneously in a shaking machine for 5 minutes, and then allowed to stand in a vertical position until the foam broke. Two end points were noted, with the results noted in the tabulation below-the time required for the first breaking of the foam to the point where the surface of the liquid could be seen a t any point, and the time required for the disappearance of all bubbles. h'o 1 2 3 4 6 7 8
TIMEFOR FIRST BREAKING TIMEFOR DISAPPE~RASCE OF OF FOAM BUBBLES Hours Mtn. Sec. Hours Mzn. Sec. 23 40 Not detd. 22 40 .. Not detd. 0 39 .. 1 1 45 Not detd' ' n 4 X n 40 _. .. 3 15 0 25 .. 0 0 4 30 0 1 10 0 4 30 0 1 10
..
The next step logically was to observe the behavior of the treated samples on boiling. This was done in round-bottom flasks fitted with reflux condensers. The results agreed in general ivith those obtained in the shaking tests, although it was obviously not possible to obtain a quantitative comparison in this case. The experiments described indicate the important influence of colloidal organic matter on the tendency of the sample to foam under the conditions employed. Interesting also is the reduced tendency toward foaming under acid conditions, although the effect is not so marked as that produced by the removal of organic and suspended matter. The tests in themselves gave no absolute assurance that if the suspended and organic matter were removed from the boiler feed water the foaming tendency of the water would be greatly reduced. The qualitative indications, however, pointed so strongly in this direction that provision has been made for a material reduction in the amount of organic and suspended matter in the boiler feed mater. A filter plant has just been completed in which approximately 250,000 gallons of boiler feed water will be treated daily with aluminum sulfate and sulfuric acid to effect the desired reduction in suspended matter. The color is reduced to 5 or less by the treatment. At this writing quantitative results of the treatment, as measured in increased permissible boiler concentrations, are not available. Qualitative observations, however, indicate a very decided improvement in this respect, and it seems reasonable t o expect even more markedly beneficial results when optimum operating conditions have been established.
Distribution of Sulfur in Oil Shale-111' E. P. Harding UNIVERSITY OF hfINHESOTA, MINNEAPOLIS, M I X X .
HE methods used, with one exception, were those described
in the first paper in the series ( 2 ) . It was found that a whiter precipitate of barium sulfate could be obtained if, after adding bromine water and acidifying the filtrate from leaching Eschka's ignition, the filtrate was concentrated nearly to dryness, made just alkaline and boiled, and the precipitate filtered off before precipitating the barium sulfate. SULFUR
SAOPAULO Per cent
the Sao Paulo District, Brazil, and the other from the Musselband Seam of Avonhead, Scotland. The preceding results were obtained. The resinic sulfur is within the limits of experimental error and may therefore be considered as not present in either * shale. The total sulfur in these shales and in those of the preceding papers is distributed as follows:
~IUSSELBAXD
Total
0,5765
0 8819
Sulfide and sulfate Sulfate Sulfide
0.3667 0.0926 0.2641
0.6800 0.1007 0.5793
Sao Paulo Musselband Seam Elk0 Nev. Greeh River, Utah
Organic Resinic Humic
0.2198 0,0007 0.2191
0.2019 0,0069 0.1950
Mount Logan, Colo.
Two shales were investigated and the results compared with those obtained in the first two papers (1,2 ) . One shale was from 1 Received
July 23, 1929.
PERCENTOF TOTAL Sulfate Organic Per cent Per cent 45.Sl 16.06 38.13 65 69 11.42 22.89 72.62 8.21 19.17 37 24 13 26 49.50 46.43 6.30 47.27
TOTAL SULFUR Sulfide Per cent Per cent
Per cent
0.5765 0.8819 4,946 1.101 1.373
Literature Cited (1) Harding and Dumke, IND.ENG.CHEM.,20, 164 (1928). (2) Harding and Thordarson, I b i d . , 18, 731 (1926).
