T H E J O U R N A L OF I N D U S T R I A L A S D E S G I N E E R I I V G C H E M I S T R Y .
842
Place the tube in the centrifuge and whirl again for 15 or 2 0 seconds. The gasoline dissolves the fat, forming a clear layer on the top. The non-fats, t h a t is the water, salt and curd, being immiscible withthegasoline and also heavier, form the lower layer. The second whirling drives the non-fats t o the lower end of the tube almost completely, a t the same time forming a sharp line of division between the two layers. The amount of non-fats is then carefully read on the tube scale. The following is a n example of the calculation of the butter fat from these two readings:
1.7 X
cc.
Total sample. ............................. Non-fats.. ................................ IOO
9.8 1.7
= 17.36per cent. non-fats. 9.8 I O O -17.36 = 82.64 per cent. butter-fats. Care should be taken that this test is made a t a fairly uniform temperature in order t o eliminate as far as possible the changes in relative volumes due t o variations in temperature. I n case the sample when first placed in the sedimentation tube is not sufficiently liquid to insure a good reading on being whirled, it may be warmed by placing it in water or in a n oven for a few minutes at a temperature not over 110' F. The results of many tests b y this method show a variation of not over 0.2 per cent. fat on the same sample, and within the limits of about 0.5 per cent, fat when compared with the official method. TABLE OF COMPARATIVE RESULTS ON PERCENTAGE OF BUTTER-FAT OBTAINED BY L-SE OF CENTRIFUGALMETHOD AND OFFICIAL METHOD. CHEMICAL Percentage butter-fat. Percentage Sample No. Official method. Centrifugal method. difference.
-
38277 38281 38283
78.68 79.81 78.06
79.12 80.30 78.56
0.44 0.49 0.50
BUREAUO F INTERNAL REVENUE. WASHINGTON.
APPARATUS AND METHOD FOR SULPHUR DETERMINATION IN PETROLEUM ILLUMINATING AND LUBRICATING OILS.' B y P. H. CONRADSON.~
The methods generally used in determining sulphur in petroleum, illuminating and lubricating oils do not give either the total amount of sulphur compounds present or how they occur. The writer has found that in many inferior, poorly refined petroleum oils large percentages of the total sulphur compounds present may be due t o sulphonates or sulphates, which altogether escape notice in the so-called lamp methods where the oil is only partly consumed in the lamp, while in the direct oxidation methods no distinction is made. I n the examination of the illuminating (kerosene) oils used in railroad service, such as in locomotive headlights or track signal lamps (long time burner lamps) which latter require a n oil with hardly any 1 Paper presented at the Eighth International Congress of Applied Chemistry, New York, September, 1912. 2 Chief Chemist, Galena-Signal Oil Co.
Nov.,
1912
diminution in the intensity of light or candle power for 175-250 hours continuous burning with no attention, or lubricating oils, such as are used in steam turbines, gas or oil engines, superheated steam valve and cylinder lubrication, high pressure air compressors or high vacuum air pumps, it is essential t o differentiate between the sulphur compounds that might be present in the oils; therefore, the writer has found it necessary not only t o burn a larger amount of oil in the lamps, but also to consume all the oil in the oil fount and make a careful examination of the sulphur compounds t h a t may remain in the wick. The accompanying photographic cut of the dpparatus1 is self-explanatory-using ordinary small kerosene burners with chimneys, well washed and dried cotton wicks about 3 mm. (I/;) in width. The lamp founts for the illuminating oils are ordinary glass beakers; for the lubricating oils, funnels having the stems cut off and fastened to a metal socket. The burners are inserted in a small disk (lid of a n ointment box with a hole cut t o fit the burner). Filter tubes of strong glass with stem bent at right angles are fit snugly over the long arm of the glass stoppered absorption tubes, which are about 350 mm. (14") in length between the constriction and exit tube and have a diameter of about 25-35 mm. (I"-II/~) and containsmallglass beads to a depth of aboutsomm. (3"). The,products of combustion are aspirated through carbonate of soda solution containing 6 grams of Na,CO, in one liter of water and standardized with I / , ~normal hydrochloric or sulphuric acid. I n testing, place 25-50 cc. of the soda solution in the first absorption tube; a t the end of the operation the soda solution is run into a beaker and the chimneys, glass filter tubes and absorption tubes are rinsed out with water; the solution with the washings is titrated, using methyl orange as a n indicator; or, the solution may be oxidized with bromine and hydrochloric acid, precipitated with barium chlorid solution in the usual way and calculated t o sulphur (S). The wicks are separately treated and examined for sulphur compounds that may remain in the same from the oil, as will be described hereafter. I L L U M I "AT1 N G 01L S
.
For low-sulphur oils such as kerosenes made from Pennsylvania crudes, 15-20 grams of oil are used. For kerosenes made from western crudes containing larger percentages of sulphur compounds, 10-1 5 grams are used. For kerosene oils intended for severe railroad service either for headlight oil purposes or in long-time burner signal lamps, it is well to make two sulphur determinations, one as above indicated and the other as follows: 425 cc. of the oil are carefully distilled in a 600 cc. Engler's distilling flask a t the rate of 2-4 cc. per minute (the slower rate a t the beginning and at the end), until 400 cc. have come over; the Engler's flask is placed on a n asbestos gauze and covered over with asbestos wool up t o the top of the neck, the ther1 I n the cut the second absorption tube of the apparatus to the right is wrongly connected.
mometer bulb placed opposite the exit tube as usual. The z j cc. residue in the distilling flask is transferred to a bottle. Often with crdinary or poorly refined kerosene oils there is formcd a deposit or sediment, more or less adhering to the sides and bottom of the flask; i t should be carefully removed and addcd to the residue in the bottle by using successively ethyl ether, chloroform, 95 pcr cent. ethyl alcohol and hot water (as the case may require), uniting and evaporating the solvents in a small dish and transferring the .final residue to the bottle by the aid of some oi the 2 5 cc. oil residue. The sulphur compounds are then
determined by burning the whole or part oi the above well mixed oil residue to dryness in the apparatus above described. LUBRICATING OILS.
Five t o I O grams of lubricating oils are burned to dryness in the lamps as stated with kerosene. Spindle oils, thin turbine oils and automobile oils will feed through the wicks until they are all consumed, with possible once or twice trimming of the formed crust; with thick, high-viscosity oils, 5-8 cc. a i highly refined lon-sulphur kerosene are added and the mixture burned to dryness or practically s o ; then 2 cc. more of the kerosene oil arc added and burned t o dryness. The soda solution and washings are treated as above described, deducting for the sulphur in the 5-10 cc. of addcd kerosene. The wicks from the above described lamp tests are treated as follows: Cut same in small pieces, transfer to a jo cc. porcelain crucible, add 0 . 2 gram pure dried
carbonate of soda and j cc. 1.42 sp. gr. nitric acid, digest on steam or water bath (cover crucible with inverted lid) till the fibers are disintegrated; then add 2 grams pure crystallized magnesium nitrate; continue the digestion, gradually raising the temperature on hot plate or protccted gas flame till the organic matter is destroyed and most of the nitrates decomposed, leaving a white residue; aiter cooling add sufficient bromine water and hydrochloric acid, boil, dilute and precipitate with barium chlorid in the usual way and calculate t o sulphuric acid (SO,). This includes the SO, both in form of sulphates and
sulphouates ii both are present. If i t is desired to estimate the latter separately, boil the wicks with 10-1: cc. strong barium hvdrate solution: dilute t o 100 cc. with boiling water; filter and wash. The filtrate is either oxidized with bromine and hydrochloric acid or evaporated with a few drops of nitric acid to dryness and slightly ignited, the residue being treated with hydrochloric acid and boiling water. The insoluble BaSO, in either case is calculated t o SO, in sulphonates. The remaining wicks with any insoluble barium salts are then oxidized with nitric acid and magnesium nitrate, the residue taken by boiling with bromine water and hydrochloric acid; the insoluble, ii any (barium sulphates), is calculated t o SO, present in the oil as sulphates. I
The usual precaution of making blank tests with the chemicals or reagents and wicks should not be omitted.
A few analyses b y the above methods are given in the iolloiving table:
T H E J O U R N A L OF I N D U S T R I A L A N D ENGI,\-EERING
844
ILLUMINATING OILS.
1 2 2a 3 3a 4 4a
Sulphur compounds in wick from sulSulphur in lamp phonates and sulcalculated to S. phates calculated Per cent. t o SO+ Kerosene original. . . . . . . . . . . . . . . . . 0.015 No SO3 Kerosene original. . . . . . . . . . . . . . . . . 0.035 Trace SO3 Kerosene in 25 cc. residue.. 0.038 Trace SO8 Kerosene original. . 0.071 0.0075 per cent. ....... 0.135 0.013 0 018 None Kerosene original. . . . Kerosene in 25 cc. residue 0.057 None
........
S.
1
2 3 4 5
Turbine oil..
.
Machinery oil. .................... Heavy gas engine oil GALENA-SIGNAL OIL COMPANY, FRANKLIN, PA.
0.035 0.098 0.354 0.345 0.080
None 0.098 per 0.018 per 0.032 per 0.074 per
cent. cent. cent. cent.
TABLEI.-REL.4TIVE
Fig. I represents a piece of apparatus that is a great time-saver in making determinations of carbon in steel drillings. It consists of a round bottle having a t mercury trap a t 2 both the inlet and 4 outlet; these make Wa it possible t o weigh the bulb without removing the oxygen. The bottle is filled, as shown, with calcium chloride and dry soda lime ; the traps with a very little freshly d i s t i 1 1e d mercury. When filled, it weighs be tween fifty a n d sixty grams and Cop.ABSORPTION BOTTLE lasts for a t least one hundred determinations where the carbon content is about one per cent. The apparatus is so simple in construction that any fairly good glassblower could make it. MIDVALE STEELCo., PHILADELPHIA.
A NEW ALLOY WITH ACID RESISTING PROPERTIES.' B y S . W. PARR.
While marked advances have been made in the development of alloys with properties which render them resistant t o the corroding influence of the atmosphere, not so much study has been given to the production of alloys which would resist the solvent action of strong chemicals. This latter function of resistance to chemical action has been given over almost wholly t o the noble metals. However, there are certain 1 Paper presented at the Eighth International Congress of Applied Chemistry, Kew York, September, 1912.
Nov., 1912
specific requirements such as ordinarily call for the use of gold or platinum where the quantity of metal involved and the excessive cost of the same make its use almost prohibitive. These considerations have led to the studies herein described in which the effort has been. made t o develop a n alloy especially resistant t o nitric and sulphuric acids. A preliminary study was first made of certain of the more common alloys with a view to determining their relative solubility in nitric acid. An arbitrary strength of acid was chosen which was obtained by diluting the ordinary strong acid of 1.42 sp. gr. in the ratio of I of acid to 3 of water, making approximately The alloys a 2 5 per cent. or 4 N solution of " 0 , . employed, together with their order of solubility, is shown in Table I. SOLUBILITY OF METALS AND
ALLOYSIN 25 PER
CENT.
NITRICACID.
CARBOR DIOXIDE ABSORPTION BOTTLE. B y W. A. KOENIG. Received April 10, 1912.
CHEMISTRY.
Percentage dissolved in 24 hours.
1 2
3 4
5 6 7
Pure iron 99 .8% pure., . . . . . . . . . . . . . . . . . 100.0 Commercial aluminum. . . . . . . . . . . . . . . . . . . 5 1.4 Monelmet 19.2 Nichrome, .................. 7.9 Copper aluminum, Cu 90, A1 1 0 . . 3.5 Nickel (79), 1.3 Ferro silicon 0.1
.........
The tests in Table I were based on the per cent. dissolved in 24 hours at room temperature. They are of value only as they show relative solubilities. Test pieces were used of approximately the same superficial area. The amounts dissolved expressed as percentages are sufficiently accurate for comparison. The range of solubilities varies widely, being from 100.0to 0.1per cent. The last two items on the list suggest the possibility of carrying the series further. Because of its physic4 characteristics of brittleness, lack of working qualities, etc., the last number, ferrosilicon, was not selected as affording a n encouraging basis for experimentation. The next to the last number however, the nickel chrome compound with a small amount of aluminum, was selected as a suitable type for further study. A series of six mixtures was arranged as in Table I1 wherein i t was sought t o determine the effect of the introduction of copper. Some such modifying element seemed necessary for the reason that the value of No. 6 in Table I was nullified t o a large extent by reason of the difficulty experienced in casting t h a t material free from flaws. The melting point of the mixture was extremely high, approximately I S O O O , and it was thought.that by the introduction of a metal of lower melting point a product would be obtained which would flow more freely and solidify without blow-holes. The series arranged, therefore, was a nickel-copper-chrome combination with decreasing amounts of copper and increasing percentages of chromium as shown in Table 11. TABLE11. Series So. Parts S i . . . . . . . . Parts Cu.,. . . . . Parts Cr.. . . . . . . Soluble in 25 per cent. HNO3--24 hours
1.
65 30 5
1
::%le
2.
3. 4. 5. 6. 80 80 75 70 5 10 5 5 10 20 20 10 15 10 0.023 0.05 0.013 0.02 1.25 per cent. per cent. per cent. per cent. per cent. 80
The interesting fact developed in this series was the
~
