T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y t h e Tolhurst Machine Works, of Troy, New York. This machine is 1 2 in. in diameter, 91/2in. high and a t a speed of 1800 r. p. m. exerts a centrifugal force of 550 lbs. According t o its concentration, from I O t o 2 5 gallons of t h e sludge are added and I O lbs. of cake obtained. The sludge cake contains about 88 per cent moisture. The space underneath t h e rim contains 0.158 cu. ft. Owing t o t h e small size of t h e machine and t o t h e fact t h a t t h e material must be scraped out, t h e time of cleaning is longer t h a n would be required for a l u g e r machine with an opening in the bottom, so t h a t a large machine could undoqbtedly have been filled and emptied more rapidly t h a n the small laboratory machine. We have found it entirely possible t o fill and empty t h e small machine 4 times in one hour. Calculating t h a t t h e same rate could be used with a 40-in. machine having 46 times t h e capacity, we could obtain in each filling 460 lbs. of sludge of 88 per cent moisture, equivalent t o 5 5 pounds of dry material. One 40-in. machine would, therefore, deliver t h e equivalent of 2 2 0 0 lbs. of dry material in a working d a y of I O hrs. On the supposition t h a t one-half ton of dry material will be obtained from I,OOO,OOO gallons of sewage, one machine would dewater t h e sludge from 2,000,000 gallons of sewage per day. The cost of t h e 40-in. machine a t present is only $ 7 5 0 and t h e power'to run it is small enough t o make t h e process appear practical for preparing sludge cake for a dryer. T h e actual cost of dewatering will depend upon t h e amount of water t h a t can be removed by t h e centrifuge, t h e size of dryer and t h e amount of coal required for removing t h e residual water. A drying test using 2 2 0 lbs. of 88 per cent sludge cake made by t h e John P. Devine Co. indicates t h a t t h e dewatering process can be made practical. The author desires t o acknowledge his indebtedness t o t h e members of t h e staff of t h e Illinois State Water Survey, and especially t o J. F. Schnellbach, F. L. Mickle, W. D. Hatfield, and E. Greenfield for their interest and assistance in carrying out t h e experimental work. STATB WATERSURVEY UNIVERSITY OF ILLINOIS. URBANA
THE ANALYSIS OF SULFATED OILS By RALPHHART Received July 19. 1917 INTRODUCTION
The present methods for t h e analysis of Turkey-red oils have proven t o be inadequate for the routine work of this laboratory where several such analyses have t o be made every day. The determinations of importance in such products are t h e percentages of total f a t and of combined sulfuric anhydride. The methods usually employed for total fat are (I) t o extract with ether, or (2) t o decompose with acid and t o measure t h e volume of t h e oil which separates. Both methods were found unsuitable for our purposes; besides other reasons, t h e former was too tedious, and the latter consumed too much time. The present method for t h e determination of combined sulfuric anhydride requires two gravimetric
Vol. 9 , No. g
analyses, and, because of its length, its application for factory control is limited. It was noted, however, t h a t this determination afforded a n excellent means of judging and controlling the manufacture of sulfated products, as is illustrated by t h e following case. A commercial Turkey-red oil, which was a t first passed as satisfactory, was found on analysis t o contain 40 per cent less bound SO3 t h a n it should have. As a result, the oil was retested in a practical way, and found t o be faulty in many respects. The cause of the trouble was later traced t o hot weather, which caused the temperature of t h e unwashed sulfated oil t o rise during t h e night. T o insure uniformity in shipments, this laboratory has made it a practice t o estimate t h e amount of f a t bound as soap, and t h e amount present as free f a t t y acids; t h e former was determined by titrating a water solution of t h e sample with H2S04 in presence of methyl orange, and t h e latter by titrating t h e alcoholic solution with NaOH in presence of phenolphthalein. It occurred t o t h e writer t h a t it might be possible t o saponify completely t h e rest of t h e f a t by ordinary means. A few experiments proved t h a t such was t h e case, and this fact was utilized t o develop a new method for t h e determination of f a t . A short method for combined so3 and ammonia was also worked out a t t h e same time. By our new procedure, we are able t o determine, within a reasonable length of time, not only total fat and sulfuric anhydride, b u t also ammonia a n d caustic soda. Furthermore, this method makes it possible t o estimate from t h e d a t a obtained for t h e other tests t h e amount of f a t present as soap, as free f a t t y acids and as esters, lactones, etc.; t h e only additional test required is for free f a t t y acids, which is determined as mentioned above. PRESENT METHOD F O R FAT
The technical procedure1 for t h e determination of f a t in Turkey-red oils, Monopole oils, Sulfo Textol oils, etc., is t o decompose with acid a sample contained in a special flask having a long neck graduated in cc., a n d t o boil t h e contents until t h e oil is clear. The latter is then brought within t h e graduation on t h e flask by pouring in a saturated salt solution. The per cent fat is then calculated from t h e volume of t h e oil and its specific gravity which is assumed t o be 0.945 a t room temperature. This method presents many difficulties; for example, during the heating, the oil which spreads on t h e surface of t h e water prevents the latter from boiling freely, and, unless the flask is vigorously and constantly agitated, t h e contents are likely t o spout out. Holde' says: "A disadvantage of t h e method is t h e fact t h a t t h e layers do not completely separate, t h e deviation in results being as much as I per cent." Another source of error is t h a t t h e contraction of t h e contents in t h e flask on cooling leaves behind a film of oil which is not taken into account, Finally, it has lately been almost impossible t o obtain a flask of this type t h a t will not break on heating. A modified method is t o heat t h e contents of t h e 1 "Examination of Hydrocarbon Oils," D . Holde, 1915 edition, pp. 409 and 410. English translation by E. Mueller.
Sept., 1917
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
flask on t h e s t e a m b a t h over night, or until t h e oil is clear. H o t salt solution is t h e n added and t h e flask is immersed in t h e s t e a m b a t h for a n hour, or until t h e oil column becomes clear. The last procedure, if carefully carried o u t , gives fairly good results a n d was used t o check our d a t a .
t o t h e partial saponification of t h e sulfo group, which occasionally occurs with some Turkey-red oils. I n case t h e sulfated oil was entirely neutralized with ammonia, a negative alkalinity will be obtained after i. e . , t h e alkalinity will be less expelling t h e ”3, t h a n t h e amount of alkali added. This is due t o t h e fact t h a t t h e NH3 in t h e ammonium salt of sulfoK E W METHOD FOR FAT ricinoleic acid is displaced by K a O H on boiling; this For our purpose, we may consider t h a t commercial displacement, which is quantitative, also occurs durTurkey-red oil consists of t h e following substances: ing saponification, a n d evidently must be subtracted (a) ammonia or soda salts of t h e acids HOC17H32.COZH, f r o m t h e saponification value. Such products can HOSO3C17H32.CO2H, a n d polymerized acids; ( b ) un- still be analyzed b y this method with good results, changed castor oil, lactones, etc. Benedict and Ulzerl as shown in t h e table on page 8jz b y Sample I , which s t a t e t h a t sulfo-ricinoleic acid is not decomposed on was entirely neutralized with ammonia. The reliability of t h e f a t determination, calculated boiling in alkaline or neutral solutions, b u t is easily decomposed into ricinoleic a n d sulfuric acid b y boiling from t h e alkalinity a n d saponification values, may be judged b y comparing t h e percentage of f a t t h u s with dilute mineral acids. T h e determination of fat, as developed in this determined (Col. 111) with t h e f a t found b y t h e flask laboratory, is carried o u t in two steps: (I) a solution method (Col. 11). Col. I V gives t h e per cent yield of t h e oil is titrated with N / z HzS04, in presence of in f a t as obtained in large commercial batches, t h e methyl orange, a n d t h e alkalinity is calculated in fat being determined according t o t h e new method. mgs. K O H per g. of sample; ( 2 ) in another sample t h e T h e average yield was 95.7 per cent, which compares saponification value of t h e unsaponified oil is de- very favorably with t h e theoretical yield of 96 per cent. termined in t h e usual manner. The s u m of t h e two A MM 0 NIA results divided b y t h e acid number of t h e original T o determine ammonia, two samples are analyzed castor oil f a t t y acids gives t h e per cent fat. for alkalinity; in one, t h e alkalinity is determined a s I n case of samples whose acid numbers are not described above, a n d in t h e second, i t is similarly known, t h e average value of 190 is assumed. T h e acid determined except t h a t t h e boiling with caustic soda i s numbers of castor oil f a t t y acids, as calculated from omitted. The difference between these two determinat h e saponification values given b y Lewkowitsch,2 lie tions is evidently due t o t h e ammonia, a n d may b e between 186 a n d 194,or a n average of 190. I n assum- used t o calculate it. This is much simpler t h a n t h e ing this figure, therefore, t h e maximum error is about usual method of distilling with excess NaOH, a n d z per cent of t h e fat, a n d since most commercial absorbing t h e ammonia in standardized acid. T h e Turkey-red oils contain about 50 per cent fat, t h e results obtained by this method were very good, average maximum error due t o this assumption is a n d are tabulated in Cols. VI a n d V I I ; where ammonia around I per cent. is reported as present, known amounts were added The success of this method depends obviously upon either t o commercial batches or t o laboratory samples. t h e complete saponification of t h e oil, a n d upon t h e P R E S E N T M E T H O D E O R SO3 accuracy with which t h e alkali bound as soap can be Sulfo-ricinoleic acid on boiling with dilute mineral determined. T h e saponification is carried out in t h e acids, as already mentioned, decomposes, giving a s usual manner b y heating with N / z alcoholic NaOH, one of t h e products, free sulfuric acid. The usual save t h a t t h e heating is prolonged t o 45 minutes. method for determining combined SOs is t o boil t h e Check analyses are easily obtained. T h e alkalinity necessary for t h e f a t calculation must oil with hydrochloric acid. The f a t t y matter is then be t h a t which corresponds t o t h e soda (or potash) soap extracted with ether a n d t h e total SO3 is determined only a n d not t o t h e ammonium soap, as t h e latter in t h e water layer as BaS04. I n another sample t h e acts like f a t t y acids during t h e saponification, a n d SO3 bound t o alkali is determined by washing t h e oil consequently t h e fat corresponding t o t h e ammonium dissolved in ether with concentrated salt solution, soap is allowed for in the saponification value. T o and analyzing the latter for HzS04. The difference this end, t h e solution is heated with a measured amount between these two gravimetric analyses gives t h e comof standardized NaOH, boiled t o expel ammonia, bined SOs. The following is a much simpler method. N E W M E T H O D F O R so3 a n d t h e n titrated with N / z H2S04 in presence of methyl orange. With a little experience, t h e endT h e oil is treated with a measured amount of standpoint offers no difficulty, a n d check analyses corre- ardized H2S04, boiled until t h e decomposition is comsponding t o 0.2 per cent fat are easily obtained. plete, a n d finally neutralized with standardized alkali E v e n where no ammonia is present, i t is best t o in presence of methyl orange. proceed in this manner, in preference t o titrating t h e The following changes t a k e place during t h e boiling: original solution directly, t h a t is, without t h e addition Z N ~ S O ~ O C ~ ~ H ~ ~H2S04 . C O ~ NzHz0 ~ of alkali. The boiling with excess alkali serves as a = Na2S04 zhiaHS04 ZHOC~~H~Z.CO~H blank on t h e saponification test, a n d avoids errors due After heating, t h e original acidityof t h e solution,in so far * “Analyse der Fette,” Benedict and Ulzer. p. 348. as methyl orange is affected, is decreased b y t h e forma2 “Chemical Technology and Analysis of Oils, Fats and Waxes,” tion of Glauber’s salt, a n d is increased b y t h e NaHSOd. Lewkowitsch. p. 641.
+
+
+ +
T H E J O U R N r l L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
8j2
I I1 I11 IV v VI VI1 PER CE:NT FAT Per Cent Acid Value PER CENTNH3 Appearance Flask New Yield of New of Water Solution Method No. Method Fatty Acids (a) Added Method Opalescent(e) 73.5 73.7 1( b ) 95.3 188 1.81 1.81 Opalescent(e) 2 77.1 77.0 96.0 Sone ... 188 3 White Emulsion.. 73.8 74.2 95.7 188 None ... White Emulsion.. , , . , . , . , . , 78.5 78.3 96.3 188 h'one Clear Soluble. . . . . . . . . . . . . . . . 36.6 36.0 95.4 188 01733 0.740 Clear Soluble. . . . . . . . . . . . . . . . 32.6 32.1 95.5 188 0.375 0.385 Opalescent. ................. 82.5 83.0 .. 188 None Opalescent ( e ) . 60.1 59.0 Assumed 190 . . . 0:364 9 Opalescent(e) . . . . . . . . . . . . . . . . 68.5 69.0 Assumed 190 ... None 10 Clear Soluble. 40.1 40.4 AswmPrl 19 1 . . . .1. ... None (a) Average yield 95.7%; theory 96.0%. ( b ) Neutralized entirely with ammonia. (c) Xeutralized partly with ammonia. ( d ) Sulfated castor oil soap. (e) Changes t o white emulsion on standing or on warming, Sample
................ ................ ...........
.
............... ...............
The net change in acidity, which is given b y t h e titration, is equal t o t h e difference between t h e total alkalinity due t o t h e soap a n d t h e acidity due t o t h e NaHS04. The total alkalinity of t h e original sample is obtained as above. Hence, t h e acidity corresponding t o X a H S 0 4 , or combined SO3, can be calculated. It is t o be noted t h a t 80 parts SO3 is equivalent, in this case, t o j6.1 parts of K O H . Cols. VI11 a n d I X give t h e results obtained b y t h e gravimetric method a n d our present method, respectively.
.. ..
Vol. 9 , No. 9
VI11 IX PER CENT BOUND SO^
Gravimetric Method 5.78
New Method 5.63
4:i2
4:69
2164 1.75
1.87 1.64
..
..
..
indistinct. Double t h e amount of caustic should be used for concentrated samples. The acid value of t h e castor oil f a t t y acid being known (188) t h e fat was calculated as follows: Fat = '"3 188 + 45.4 = 36.0 per cent
COMBINED SULFURIC AKHYDRIDE-Eight grams were gently boiled for one hour with 2 j cc. of standardized HzSOa solution in a 300 cc. Erlenmeyer flask, provided with a condenser as for saponification. The flask was frequently shaken. Before disconnecting, the condenser was washed out with water by a PROCEDURE spray from a wash bottle. The sample was then titrated with Below is given in detail t h e analysis of a Turkey-red caustic soda. The end-point w^s best observed by adding excess oil which was partially neutralized with ammonia. alkali and finishing the titration with acid. I t took 21.15 cc. T h e solutions required are: standardized N / P HzS04, of the alkali to neutralize the excess acid ; the titer of the alkali N / z NaOH, a n d approximately N / 2 alcoholic NaOH. was 24.48 and of the acid 31.4 (in the calculation, it should be All titrations were made in presence of methyl orange, kept in mind that the acid is partly neutralized by the alkali in the oil, which, in this case, is equivalent to 46.5 mg. KOH). unless otherwise indicated. Combined SOa TOTAL ALKALINITY-Ten grams were weighed into a z j o cc. 21.15 X 24.48 - 25 X 31.4 Erlenmeyer flask, balanced on a scale sensitive to j mg. (all 4 6 . ~ ) ~ % = 1.87 per cent 8 weighing were made in this manner), I j o cc. water added, and CONCLUSIONS titrated with N / z H2SO4. The titer of the acid was 27.02 I-Turkey-red oils a n d similar products are commg. KOH, and the titration required 1 7 . 2 cc. pletely or nearly completely saponified by N / 2 alcoholic 17.2 X 27.02 Total alkalinity = = 46.j mg. KOH per g NaOH.
=(
+
IO
VOLATILIZED-Eight grams were dissolved in IOO cc. water in a joo cc. beaker, 2 j cc. A'/ z NaOH added, and gently boiled until litmus paper no longer indicated ammonia (about one-half hour). Water was added and the alkali titrated with N 1 2 H2S04. The titer of the caustic was 27.30 mg. KOH,the acid 27.02, and it took 31.8j cc. of the latter for the titration. ALKALIXITY AFTER
WAS
3"
Alkalinity without ammonia 31.85 X 27.02 - 25 X 27.30 .- = 22.3 mg. KOH 8
Should t h e sample contain a high percentage of fat (shown b y t h e high viscosity and also by t h e fact t h a t such samples give with warm water white emulsions) double t h e amount of caustic soda should be used. F r o m t h e above d a t a , t h e ammonia was calculated as follows: Ammonia = 46.5 - 22.3 = 24.2 mg. KOH, or, 0.733 per cent
LABORATORY L. SONNEBORN SONS,INC. N E W YORKCITY
THE DETERMINATION OF TANTALUM IN ALLOY
"3.
vALuE-Eight grams were weighed into a 250 cc. Erlenmeyer flask provided with a long glass tube to serve as a reflux condenser, and 2 j cc. L V I Z alcoholic NaOH added. The flask was heated on a steam bath for 45 minutes, neutral alcohol added, and excess NaOH titrated with N / z acid in presence of phenolphthalein. The blank took 23.4 cc. of acid, the titration required 9.95 cc., and the titer was SAPONIFICATION
27.02.
Saponification value
11--Alkali bound as soap can be determined b y titrating its solution with acid in presence of methyl orange. 111-It is feasible t o calculate t h e combined SO3 from t h e increase in acidity due t o t h e splitting of t h e sulfo group. IV-Based on these fundamentals a rapid method has been developed whereby sulfated oils can be analyzed for fat, ammonia and caustic soda bound as soap, and for sulfuric anhydride in t h e form of sulfo-ricinoleic acid. Acknowledgments are due t o Dr. F. Sonneborn a n d t o Dr. F. W. Breth of this laboratory, for valuable suggestions a n d corrections.
=
(23.4
- 9.95) 27.02 = 45,4 mg. KOH 8
The alcoholic caustic should be filtered t o remove carbonate. The titration should be carried out immediately after saponification. as otherwise t h e absorption of COz from t h e air makes t h e end-point
STEELS By G. I,. KELLEY.F. B. MYERSA N D C. B. ILLIKGWORTH
Received June 21, 1917
The number of methods so far published for t h e determination of t a n t a l u m in steels is small. Most of these deal with t h e determination of t h e element in a carbon steel a n d do not indicate methods available for use with steels of a more complex character. T h e methods outlined below may be used for t h e determination of t a n t a l u m in steels containing nickel, cobalt, aluminum, chromium, vanadium a n d tungsten in addition t o other elements usually present in steel. Titanium interferes.
