1006
T H E J O U R N A L O F 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 Vol.
t o be applicable in cases in which t h e acid formed is comparatively stable toward t h e reagent. 0.231 g. oxime, dissolved in a few drops of methyl alcohol, was mixed with 2 cc. N I P potassium hydroxide, and 5 per cent permanganate added gradually until no further oxidation took place. The manganese oxide was then dissolved by sufficient sulfurous acid, the mixture strongly acidified, and the acid taken out with ether. 0.145 g. acid was obtained, which, as it was still contaminated with an oily impurity, was again treated in the same way with permanganate. The acid solution was not extracted with ether, but was allowed to evaporate. After a few days, the greater part of the acid had separated in two large, well-formed prismatic crystals, apparently monoclinic, melting a t 89' (corr,), and evidently methyl salicylic acid. A careful comparison with the synthetic acid showed the identity of the preparations, both crystallizing from alcohol in distinct characteristic prisms, showing under the microscope oblique extinction, and a @-angleof about 4g0, as described by Graebe.1 E X A M I N A T I O N O F THE N O N - A L D E H Y D E S E C T I O N
The portions of t h e oil insoluble in bisulfite showed t h e following properties:
................ .................... ................... .......... .....
Sp. gr. a t 25O.. Rotation.. Acid value.. Saponification value., Calc. as cinnamyl acetate..
A 1.020 +0.50° 4.0 170.0 53.4 per cent
B 0,9926 4-0.75 6.0 110.0 34.5 per cent
For further light on t h e composition of this section, 38 g. of non-aldehyde A were saponified and distilled with steam. About 1 2 cc. of iight oil were obtained, the greater p a r t of t h e alcoholic product remaining
IO,
No.
12
dissolved in t h e aqueous distillate. T o remove alcohols, t h e oil was washed with 50 per cent resorcin solution, which left a residue of 6.25 cc. light oil, very insoluble in alcohol, a n d almost unattacked by permanganate. This, in fact, appeared t o be a petroleum section, evidently due t o a n adulteration of t h e crude oil. T h e aqueous distillate, on ether extraction, yielded a small amount of heavy oil, which gave benzaldehyde on oxidation with permanganate, and was probably, in p a r t a t least, cinnamyl alcohol. The alkaline residue from t h e distillation was found t o contain acetic and cinnamic acids, a n d t h e liquid acid with fruity odor, previously noted. A comparatively large amount of resin was formed in the saponification, t h e cause of which remains unexplained. T o conclude, oil of cassia has been found t o contain t h e following compounds: Previously known: Cinnamic aldehyde, 75 to go per cent Cinnamyl acetate Phenyl propyl acetate (?) Methyl ortho-coumaric aldehyde Found by the writer and Sherndal : Salicylic aldehyde, 0 . 1 to 0.2 per cent Coumarin Benzoic acid Salicylic acid Liquid acid of fruity odor Found by the writer: Benzaldehyde Methyl salicylaldehyde LABORATORY OF THE
DODGE AND
OLCOTT COMPANY
BAYONNE, NEWJERSEY
LABORATORY AND PLANT METHODS OF ANALYSIS USED I N THE COAL-TAR INDUSTRY. IV-BENZOLS AND LIGHT OIL B y J. M. WEISS Received October 24, 1918
BENZOLS
(SPINDLE) APPARATus-Hydrometer.2 The necessary ranges for this class of compounds are 0.79 t o 0.87, 0.86 t o 0.94, and 0.93 t o 1.01. METHoD-see B4.3 Benzols shall always be taken a t 15.5' C. (60' F.) and no correction shall be made of a reading taken a t a different temperature. NOTE-AS under B4. T E S T E3-SPECIFIC G R A V I T Y (WESTPHAL) All matter as t o apparatus, method, precautions, and notes as given under H44 apply t o this test on these materials. SPECIAL NOTE-This method is t h e reference method for benzols and must be used in all cases where accuracy is required as in cases of dispute or check testing. TEST E4-DISTILLATION O F PURE PRODUCTS APPARATUS-F~BS~:T h e distillation flask shall be a zoo cc. side neck distilling flask having the following dimensions: TEST EP-SPECIFIC
1 2
4
GRAVITY
Ann., 189, 137. See Fig 11, Paper I, THIS JOURNAL, 10 (1918), 735. THISJOURNAL, 10 (19181, 735. Ibid., 10 (19181, 911.
...................... ........ ................. ........................
Diameter of bulb.. Outside diameter of neck. . . . . Inside diameter of neck Length of neck.. Inside diameter of side t u b e . . . . . . . . . . . . . . Length of side t u b e . . Side tube joined t o neck above the has the neck..
................ .........................
73 mm. 24 mm. 21 mm. 105 mm. 5 mm. 127 mm.
(2.881 (0.945 (0.826 (4.134 (0.197 (5.000
in.) in.) in.) in.) in.)
in.)
52 mm. (2.047 in.)
The side tube shall be set so t h a t the smaller angle where it joins t h e neck is 7 5 ' . The allowable variation from the above dimensions shall be not more t h a n j per cent. See Fig. XVI. Thermometer: This shall be graduated from 70' to 120' C. a t intervals of 0.2' C. It shall be made of a suitable quality of glass so as not t o change its reading under conditions of use. It shall be provided with a n expansion chamber, a n d a ring a t t h e top for attaching tags. It shall conform t o the following dimensions:
..........
Total length.. Bulb length.. 70° mark t o bottom of b u l b . , Graduations per inch.. Stem diameter.. Bulb diameter..
.....
Not over 305 mm.
............................ N o t over 20 mm. ............. 80 t o 100 mm. ................... N o t over 35 mm. 5 t o 7 mm. ......................... ......................... 5 t o 7 mm.
The thermometer shall be accurate t o 0.2' C. at total immersion and shall be compared before use with a similar thermometer calibrated a t full immersion b y the Bureau of Standards, and proper correction applied. It is preferable t h a t this instrument shall not have
Dec., 1918
'
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
a supplementary bulb situated between t h e lowest graduation and t h e main mercury reservoir. However, if such a chamber is present, its lowest point shall be not more t h a n I mm. above t h e top of t h e main reservoir. Condenser: The distillate shall be condensed in a straight t u b e of l / 2 in. internal diameter and 24 in. in length, set a t an inclination of 7 5 " t o t h e vertical. A t least 1 5 in. of tube shall be cooled with cold water in a trough condenser. Burner: The heating flame shall be derived from a Bunsen burner and t h e entire flame shall be blue. Cylinder: An ordinary IOO cc. cylinder, graduated at intervals of I cc., shall be used for t h e receiver. Graduations must be clear cut and distinct. The graduate shall be approximately I in. in diameter. The mark for each I O cc. shall be longer t h a n t h e intermediate markings and shall be plainly numbered.
FIG.XVI-ASSEMBLY
OF
BENZOLDISTILLATION TEST
Assembly of Apparatus:
Shown in Fig XVI.
The
flask shall be supported on a sheet of l/s-in. asbestos board, 6 in. X 6 in., with a hole in t h e center I in. in diameter. The asbestos board shall be supported on a circular metal shield enclosing the Bunsen flame. The flask shall be so placed t h a t t h e vapor tube will extend a t least 2 in. into t h e condenser tube. The thermometer shall be held in t h e neck of t h e distillation flask by means of a cork stopper in such a position t h a t t h e top of t h e bulb shall be opposite t h e lower side of t h e side t u b e and central in t h e neck of t h e flask. ivmTHoD-The sample t o be tested shall be poured into a IOO cc. graduated cylinder and I O O cc. of t h e material shall be carefully measured and transferred t o the distilling flask. The flask shall be put in connection with t h e condenser and t h e thermometer introduced through a tightly fitting cork. The graduated cylinder which was used t o measure t h e oil shall not be rinsed out b u t shall be placed under t h e lower end of the condenser tube t o catch t h e distillate. The flask shall be heated up slowly, especially after ebullition has begun, so as t o allow the mercury column of t h e thermometer t o become fully expanded before t h e first drop distils off.
1007
The flame shall then be turned up a n d t h e distillation conducted a t t h e rate of 5 cc. per min. ( 2 drops per sec.). This rate must be exact. The distillation shall be continued t o dryness. The total yield of distillate shall not be less t h a n 95 per cent. A temperature reading shall be taken when t h e first drop of distillate falls into t h e receiving cylinder. Additional temperature readings shall be taken when 5 per cent and 95 per cent of distillate have distilled over. A final reading shall be taken of t h e "dry') point, which is t h e point a t which liquid just disappears from t h e bottom of t h e flask. PREcAuTIoNs-care must be taken t o quickly remove the burner as t h e last bubble is evaporated, otherwise, too high a dry point may be produced b y superheating. NOTES-The method given applies t o pure benzol and pure toluol. The specifications for pure benzol and pure toluol require t h a t distillation from first drop t o dry shall be complete within a 2' C. range and, further, t h a t t h e true boiling point of t h e product in question shall lie within t h a t range. To be sure t h a t t h e true boiling point is strictly within this range i t will be necessary, of course, t o correct t h e observed temperature readings for variations from t h e standard thermometer, both for inaccuracy and for stem immersion; also correction should be made for differences in barometric pressure. The barometric correction factors for each mm. of difference are as follows, these factors being applied directly as t h e difference in t h e barometric pressure may be greater or less t h a n 760 mm. Benzol.. ........................... Toluol.. X y l o l . . ............................
...........................
0.043' 0.047 ' 0.053'
It is not necessary in ordinary . require t h e chemist t o apply these
works practice t o corrections t o each test. For instance, if the material is one which boils entirely within a 2' range, around, say, from 77' t o 81' C.,when t h e corrections are applied t h e results will all fall within a similar 2 " range. The same applies t o a 2' range between 108" and 1 1 2 ' C. I t is recommended, however, t h a t such corrections be applied when t h e sample is t o be checked against results obtained by another investigator, and in reporting results in such a case, a notation should be made t o t h e effect t h a t these results have been corrected for t h e variations mentioned. An examination of all available literature on such subjects will show t h a t t h e authorities vary materially in their report of findings of t h e true boiling points of benzol, toluol and t h e three xylol isomers. The following figures, however, are considered sufficiently accurate for all commercial practice. Benzol.. ........................ Toluol Para-xylol.. Meta-xylol.. ..................... Ortho-xylol.
..........................
.....................
.....................
80.2' 110.4' 137.5' 138.5' 142.3'
C. C.
C.
C. C.
The emergent stem corrections should be made as f 0110 T?'s:
T H E J O U R N A L O F 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 Vol.
1008
Let C = Number of degrees centigrade t o be added t o the observed temperature. N = Number of degrees of the stem exposed. T = Average temperature of the bulb. t = Average temperature of the stem. K = Correction factor for the thermometer, d. e., the difference between the coefficients of expansion of mercury and glass. Then C = K N (T t),
-
EXAMPLE.
Observed temperature = 80' C. Stem temperature = 25' C. Degrees emerging (from top of flask to 80' C.) = 15' C. Thermometer coefficient = 0.000154 80' C. 25' C. = 5 5 0 c. 15" X 55' X 0.000154 = 0.12787 = 0.13' C. Temperature corrected for emergent stem = 80.13O C.
-
T E S T E5-DISTILLATION
O F COMMERCIAL BENZOLS
APPARATUS-Exactly as given for E 4 with t h e following exceptions: ( I ) The thermometer shall be a standard 0' t o 400' C. thermometer (see C9)'; (2) For materials boiling substantially below 145' C. a I-in. hole shall be used in the asbestos board on which t h e flask is supported. For materials boiling substantially above 14 j ' C. a 2-in. hole shall be used. METHOD-The distillation shall be conducted exactly as given under E4. "Special Specification Xylol" shall be read first drop, 5 per cent off, 50 per cent off, 95 per cent off, and dry, as under E4. All other materials, except "Pure Xylol," shall be read a t first drop, and then volume readings taken a t every even 5 " C. up t o t h e dry point, thus: Deg. C. 77
Per cent 1 s t drop 10 65
78
83 90 98 Dry
'(Pure Xylol" shall be read, first drop, every I ' C., and dry. PRECAUTIONS-same as under E4. NOTES-In light fractions it is well also t o determine loss by pouring t h e liquid t h a t recondenses in t h e flask into t h e graduated cylinder and noting t h e total volume. The difference between t h e reading and IOO gives t h e approximate result for "loss." I n some cases on t h e xylols where special accuracy is required a thermometer graduated from 110' t o 160' C. in 0.2' C. intervals is used. This is not necessary for ordinary practice. The specification, except for scale range, is t h e same as for t h e 70' t o 1 2 0 ' thermometer given under E4. This test, as well as E4, has been compiled from our experience and also from matter given in t h e Gas Chemists' Handbook, page 180, t h e standard method for distillation of paint thinners (A. S. T. M., D-28-17), and t h e article2 by F. W. Sperr, Jr., of the H. Koppers co. T E S T E6-SULFURIC A C I D WASH APPARATUS-Standards: The set of color standards against which wash tests shall be compared shall consist of fifteen bottles (French square flint glass, glass stoppered, one ounce capacity) each containing 1 2
THISJOURNAL, 10 (1918), 819. Met. & Chem. Eng., Nov. 1 5 , 1917, p. 586.
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No.
12
one of t h e colored solutions made up as given below, t h e bottle being sealed. For making up t h e standards t h e following basic solutions shall be used: A-59.496; g. CoC1~.6Hz0(nickel-free) made up t o 1000 cc. with a mixture of 2 5 cc. 31 per cent HCl and 97 j cc. H 2 0 . B-4j.054 g. FeC13.6HzO made up t o 1000 cc. with a mixture of 2 5 cc. 31 per cent HC1 and 975 CC. HzO. C-3.5 volumes of Solution A 36.5 vol. Solution B 90 vol. of H20. 36.5 volumes of D-3.5 volumes of Solution A Solution B. (No water is added.) E-Solution of KZCr04 saturated a t 21 O C. F-One volume of a solution of KZCr20, saturated a t 21' C. one volume of HzO. As standard color solutions t o be used for comparison t h e following shall be made up and numbered from o t o 14: No. o-Pure water. No. I-One volume of Solution C I volume of HzO. No. z-j'/z volumes of Solution C 2 volumes of HzO. No. 3-Solution C as such. No. 4-One volume of Solution D one volume of H20. KO, j-*l / Z volumes of Solution D two volumes of HzO. No. 6-solution D as such. No. 7-5 volumes of Solution E z volumes of water. No. 8-Solution E as such. volumes of Solution E l / z volume of No. 9-7 Solution F. No. 10-6~/2 volumes of Solution E one volume of Solution F. No. I I - ~ ~ / z volumes of Solution E two volumes of Solution F. No. 12-One volume of Solution E one volume of Solution F. No. 13-Two volumes of Solution E 5 volumes of Solution F. No. 14-Solution F as such. These standard solutions shall, in all cases, remain stoppered and sealed t o prevent evaporation. Test Bottles: These shall be one-ounce, French square, glass-stoppered, flint glass bottles identical in every respect with those containing t h e standard solutions. (A suitable bottle is shown in t h e Whitall T a t u m 1910 catalogue, p. 21.) METHOD-7 cc. of 96 per cent C. P. sulfuric acid shall first be placed in a test bottle and approximately 2 1 cc. of t h e material t o be tested shall be added. The bottle after being stoppered shall be thoroughly and vigorously shaken for 15 t o 20 sec. and allowed t o s t a n d for t h e specified time. (See Notes.) The resulting color of t h e acid layer shall be compared with t h e set of standards and t h e number of t h e bottle in t h e standard set corresponding t o t h e test bottle shall be noted.
+ +
+
+
+
+
+ +
+
+
+ + + +
.
Dec., 1918
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
PREcAuTIoNs-If t h e color of t h e acid layer is not uniform, it should be carefully mixed b y slowly inverting bottle once or twice. 96 per cent sulfuric acid must be used. Some C. P. acid obtained is only 94 per cent and care must be taken t o see t h a t the strength is of the proper degree. NoTEs-In pure benzol and pure toluol testing t h e benzol or toluol layer must remain white, and t h e color of t h e acid layer, after standing I j min., must not be darker t h a n No. 4. For go per cent benzol and all grades of benzol and toluol other t h a n pure, t h e benzol or toluol layer must remain white, and t h e color of t h e acid layer a f t e r standing I j min. must not be darker t h a n No. 6. For solvent naphtha t h e acid layer color only is noted, and after standing j min. i t must not be darker t h a n No. 14. It is well t o note t h a t t h e above schedule shows t h e limit of color allowable in t h e sales specifications, and i t is t o be expected t h a t t o consistently pass t h e test, works practice should call for a limit of a t least one number lighter i n each case. This test is not used on crude benzols. T h e color standards are a modification of t h e old Barrett Company standard practice made by t h e Semet-Solvay Company. S P E C I A L NOTE-In making t h e wash test upon a n agitator charge, this being recommended as a guide in determining whether material in question has been sufficiently washed t o warrant making final distillation, it is necessary t o first make t h e sample alkaline b y shaking with some of the caustic soda solution which will be used in t h e factory upon t h e wash. This is best carried out in a separatory funnel. After shaking, t h e mixture is allowed t o settle and t h e soda solution drawn off as thoroughly as possible. I O O cc. of t h e neutralized oil are then measured in a graduated cylinder and transferred t o a 2 0 0 cc. distilling flask. No thermometer need be used in this distillation, b u t care should be taken t o make t h e distillation through a condenser which has been used €or pure products, so t h a t t h e distillate may not be contaminated i n t h e condenser. The first j cc. distilled off are rejected. Then 7 0 cc. are distilled off and caught i n a clean graduated cylinder. The cylinder which was used t o measure t h e material into t h e flask should not be used for this, as i t would tend t o contaminate t h e distillate. The 7 0 cc. of distillate t h u s caught are filtered through a clean, dry, white filter, and tested for wash as described. If t h e resulting test is entirely satisfactory, t h e factory alkali wash and result in distillation may be safely relied on. TEST E7-CARBON
BISULFIDE
APPARATUS-Erlenmeyer flask, rough balance, burette, separatory funnel 2 j o cc. capacity. REAGENTS-sO1UtiOn of alcoholic caustic potash, prepared by dissolving I I O g. of potassium hydroxide in 900 g. of absolute alcohol. Standard solution of copper sulfate ( I cc. equivalent t o 0.007 j g. CSz), prepared
1009
by dissolving 12.475 g. of CuS04.jHz0 i n one liter of distilled water. Potassium ferrocyanide solution. Acetic acid solution. &IETHOD-EX&CtlY jo g. of t h e benzol t o be tested shall be weighed into a n Erlenmeyer flask, mixed well with jo g. of alcoholic potassium hydroxide solution, t h e flask stoppered and t h e mixture allowed t o s t a n d for j or 6 hrs. a t t h e ordinary temperature. T h e carbon bisulfide by this treatment is converted t o potassium xanthate. T h e mixture shall then be shaken up with about IOO cc. of water and t h e aqueous layer separated from t h e benzol. This washing shall be repeated several times with 30 cc. portions of water, adding t h e washings t o t h e original water solution. The solution shall then be diluted t o 2j0 cc. and a n aliquot portion removed, neutralized with acetic acid, and titrated with copper sulfate solution. The end-point shall be determined by placing a drop of t h e solution on a filter paper next t o a drop of potassium ferrocyanide solution. The completion of t h e titration is indicated b y a reddish brown zone of copper ferrocyanide. Cc. CuS04s o h . X3.75 =per cent CSz. C A L C U L A T I 0 N SCc. taken for titration soTE-The above quantity of alcoholic caustic potash is sufficient if t h e benzol contains less t h a n j per cent of carbon bisulfide. If it contains more, a smaller sample should be taken. I n this case, t h e formula for calculation must be modified accordingly. T E S T E8-PARAFFINS APPARATUS-Babcock milk bottles. Centrifuge. Pipette, I O cc. funnel, with capillary stem. REAGENTS-FUming sulfuric acid, 2 0 per cent free
so3.
METHOD-IO cc. of t h e benzol t o be tested shall be measured into t h e Babcock bottle, and I O cc. of t h e fuming sulfuric acid slowly added t o i t , cooling t h e bottle in a bath of ice water during t h e addition of t h e acid, and shaking t h e bottle vigorously after each addition in order t o thoroughly mix t h e contents. After t h e addition of t h e acid is complete, t h e bottle shall be removed from t h e ice bath, shaken until t h e temperature rises t o about 40' C., and then alternately cooled and shaken for a period of I j min., keeping t h e temperature below 40° C. Then t h e mixture shall be cooled again, I O cc. more of t h e fuming sulfuric acid added, t h e whole mixed thoroughly and shaken and cooled as above, keeping t h e temperature below 40' C. Finally t h e mixture shall be allowed t o s t a n d for 30 min. a t a temperature of about 3 j" C. Then t h e bottle shall be cooled in ice water and water added through t h e capillary stem of t h e funnel so t h a t i t enters below t h e surface of t h e acid. The water shall be added in small portions very cautiously and t h e bottle thoroughly shaken and cooled after t h e addition of each portion. When sufficient water has been added t o bring t h e level of t h e liquid well u p on t h e graduated portion of t h e neck, t h e bottle shall be placed in t h e centrifuge and whizzed for 5 min. T h e paraffins present will rise t o t h e surface and their volume shall then be read off in terms of t h e
IO10
T H E J O U R N A L O F 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 Vol.
graduations on the neck of the bottle. This reading (in major divisions) multiplied by 2 gives directly the volume per cent of paraffins in the original material. PRECAUTIONS-The graduated portion of the bottle should be 2 cc. divided into I O major divisions. These are further subdivided into j or I O divisions each. The readings should be taken in terms of t h e major divisions ( 0 . 2 cc. each). NOTES-011 diluting the sulfonation mixture with water i t will frequently happen t h a t a small quantity of solid sulfone will be formed, which, on centrifuging, will form a layer between the paraffins and the acid layer. This sulfone should not be mistaken for paraffins. I n benzol work we have found it necessary t o carry on t h e dilution with water rather t h a n concentrated sulfuric acid in order t o prevent solution of paraffins in the mixture. TEST EQ-HYDROGEN
SULFIDE
APPARATUS-Balance. Separatory funnel, 2 j o cc. Beakers, funnels, desiccator, crucibles, etc. REAGEKTS-sodium hydroxide c. P., I O per cent solution. Bromine water, sulfur free, saturated solution. Barium chloride, 5 per cent solution. METHOD-100 g. of t h e benzol shall be shaken thoroughly in a separatory funnel with 2 5 cc. of sodium hydroxide solution, t h e liquids allowed t o settle and the lower layer drawn off into a beaker. The water layer shall be diluted t o 400 cc., about 2 0 cc. of t h e bromine water added, t h e mixture acidulated with hydrochloric acid, t h e excess bromine boiled off and the sulfuric acid in t h e solution precipitated in the usual manner with barium chloride. The barium sulfate shall be filtered and weighed. A blank determination shall be made on t h e same amounts of t h e materials used in the analysis and t h e weight of barium sulf a t e deducted from t h a t obtained from t h e benzol. CALCULATIONS-weight of barium sulfate X 0.1460 = per cent of HZS. NOTES-Before procee,ding with determinations of HzS and SOz a qualitative test should first be made in order t o determine which of t h e two is present. This can best be done at t h e time of performing t h e disti1lation test, E4 or E j , by hanging strips of moistened lead acetate paper and starch iodate paper on t h e end of the condenser tube. If t h e lead acetate paper shows discoloration, HzS is present, but not SO2. I n this case both papers will usually be discolored. If t h e lead acetate paper shows no discoloration b u t t h e starch iodate paper develops a blue color, SO2 is present b u t not HzS. If neither paper shows discoloration, neither is present. As H2S and SOz mutually react both cannot be present simultaneously. T E S T EIO-SULBUR
DIOXIDE
Apparatus, reagents, a n d method of analysis are precisely t h e same as E9. CALCULATIONS-weight O f barium Sulfate x 0 . 2 7 4 4 = per cent SOZ. POINT O F PURE BENZOL
TEST EII-SOLIDIFYING
APPARATUS-Test-tube diameter. Thermometer, 400 cc. capacity. 1
j 0 '
THISJOURNAL, 10 (1918), 820.
in. long b y I in. inside t o 80' (see D6).* Beaker,
IO,
No.
12
METHOD-4%bout 2 0 cc. of the benzol t o be tested shall be poured into t h e test-tube and cooled in a bath of ice and water contained in a beaker, stirring continuously with a thermometer. When the solid benzol begins t o separate t h e temperature will remain constant for some time. This temperature shall be taken as t h e solidifying point. ACCURACY-
*
'.
0.05
LIGHT OIL
This material is tested for water, specific gravity, t a r acids, and t a r bases as described under heavy oil tests.l Other special tests are made as follows: TEST Bj-BULB
DISTILLATION
All matter as t o apparatus, method, precautions and notes as given under E j for materials boiling substantially above 13 j ' C. apply t o this test on these materials. SPECIAL NOTE-with light oil, a dry point is ordinarily not taken, t h e distillation being continued only until about 95 per cent of the material has distilled over. Readings should be taken a t first drop and every even 10' C. TESTS
F6
ACIDS ( C O N T R A C T I O N AND L I B ERATION METHODS)
A N D F7-TAR
These should be carried out exactly as given u n d e r H I I and H I Z . TEST F~-HEMPEL
DISTILLATION
APPARATUS-Flask, short ring neck, 2 0 0 cc. Hempel tube. Condenser and stand. Thermometer, o o to 400' (specifications as under C9).2 The assembly of the apparatus is shown in Fig. XVII.
FIG.XVII-ASSEMBLY OR HEMPEL EVALUATION TESTFOR LIGHTOIL
hiETHoD--After t h e extraction of t a r acids from Z O O cc. of oil t h e residual oil shall be placed in t h e 2 0 0 cc. bulb and the apparatus assembled as in Fig. XVII. Heat shall be applied and t h e distillation conducted a t t h e rate of I t o 2 drops per sec. The volume which has distilled at 130' C., 170' C.,and 200' C., shall be noted and recorded. The flame shall be removed when t h e thermometer reaches 200' C. 1 2
THISJOURNAL, 10 (1918) 911. Ibid., 10 (1918), 819.
Dec., 191s
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
NoTEs-This test is a very rough evaluation test used for comparison purposes between oils. The 130' fraction roughly represents crude benzol and toluol; t h e 130' t o 170' fraction, crude solvent; and t h e 170' t o 200' fraction, heavy naphtha. If more exact information is desired, t h e test given under F I O should be used. The residue in the bulb should be preserved for Test F g if this is desired. T E S T F9-CRUDE
'
FIO-DETERMINATION
OF
BEKZOL
AND
PL*N
TOLUOL
.4s~~RATus-Distillation apparatus shown i n Fig. XVI. Partial condenser distillation apparatus shown i n Fig. X V I I I . We shall be glad t o furnish a detailed drawing of this apparatus t o any who desire t o procure t h e otitfit. Three thermometers, 0' t o 200') previously standardized, and accurate t o a t least 0.5 '. One thermometer, 70' t o I~o', graduated in 0 . 2 ' intervals. One thermometer, 110' t o 160', graduated in o z ' intervals. Three graduated cylinders, capacity IOO cc. One separatory funnel, capacity 2 liters. Westplial balance. Hempel distillation apparatus shown in Fig. XVII. Steam distillation apparatus. REAGENTs-Sulfuric acid, 60' BB., commercial. Sulfuric acid, 66' BC., commercial. Caustic soda solution, I O per cent. Pure toluol, boiling within '~',11 C., sp. gr. a t 15.5' C. not less t h a n 0.870. METHOD: Preparation of Sample-Ioo cc. of the sample to be analyzed shall be distilled following the procedure of E.5. A larger sample of the oil, accurately measured a t 25' C., shall now be distilled, using a Hempel column and collecting the fraction boiling below 160' C. T h e dieerence between this fraction a n d the original sample shall be noted as "heavy oil." The size of sample taken shall be so regulated by the results obtained in the preliminary boiling test t h a t about 1000 cc. are obtained in this distillation. If the preliminary distillation shows g o per cent or more a t 160' C . , the Hempel distillation may be omitted. A c i d Wash-The fraction up t o 160' C. shall now be washed in a separatory funnel with I per cent by volume of 60" BB. sulfuric acid, care being taken t h a t the oil is kept cool during the washing. The acid sludge shall be drawn off and t h e oil washed with three successive portions of 2 volumes each of 66' BC. sulfuric acid, t h e acid sludge being drawn off after each washing, The oil shall finally be washed with a dilute solution of caustic soda and this drained off. The washed oil shall be p u t into a steam distillation apparatus a n d distilled with steam until no further oil comes over The upper oil layer shall be carefully separated from the water in a separatory funnel and *THISJOURNAL, 10 (1918),916.
measured a t 2 j ' C. The difference between this volume and t h e volume before washing is noted as "loss in washing" and represents unsaturated hydrocarbons. T h e refined fractions so obtained should consist entirely of benzol, toluol, solvent, and possibly saturated paraffin hydrocarbons.
NAPHTHALENE
APPARATUS-same as used under H17.l YIETHoD-The residue above 200' c. obtained in Test F8 shall be transferred t o the copper beaker, cooled t o 15.5' C., and held a t this temperature for 3 0 min. It shall then be filtered and pressed as described under H17. The weight of dry solids divided by the specific gravity of the original oil gives the per cent by weight of crude naphthalene. TEST
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E L EVATI ON
€ N D Vifw
FIG.XVIII-ASSEMBLY on PARTIAL CONDBNSER
If the preliminary distillation showed less t h a n 40 per cent distilling between 100' C. and 1 2 0 " C., thistrejned fraction should be mixed with an equal colume of pure toluol beJore being subjected to analysis. I n this case the quantity of material originally taken for analysis need be only about half t h a t normally necessary, since the volume of t h e total oil t o be fractionated should be 7 0 0 t o 1000 cc. Fractionation o j Material-The refined fraction, which should approximate one liter, shall .now be introduced into t h e 1'/2 liter bulb of t h e partial condenser apparatus. T h e t a n k of the partial condenser shall be filled with a high boiling oil agitated by means of a small motor-driven agitator. T h e oil in t h e t a n k shall be heated up t o 7 0 ' C. a n d the distillation of refined oil begun. The material in t h e flask shall be kept boiling vigorously so t h a t the flame under t h e partial condenser may be turned off and the temperature continue t o rise from condensation of vapors. The distillate shall be collected in I O O cc. cylinders, these being changed when nearly full, brought t o a temperature of 25' C., and measured. As the temperature of t h e oil approaches So" C. the distillation will very nearly stop and when very near the temperature of 80' C. a sudden increase in the rate of distillation will be noticed. This is when the benzol begins t o come over in large quantities. The receiver shall now be changed and all fractions up t o this point combined. This shall be called Fraction A. T h e distillation shall be continued, allowing the temperature of the oil in the oil bath to gradually rise. The rate of distillation will gradually slacken until just below 1 1 0 " C., when it is again practically stopped. At about this temperature the rate will again suddenly increase, the toluol coming over. When about 5 0 cc. of material have distilled beyond this point, the receiver shall be again changed a n d the fractions between the benzol cut and the toluol cut combined into Fraction B.
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T H E J O U R N A L O F I N D U S T R I A L A N D E N G I N E E R I X G CHE&fISTRY Vol.
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.As t h e temperature of t h e oil bath continues t o rise t h e rate of distillation will again decrease and will suddenly increase when t h e xylol boiling range is reached at about 137' C . The third cut shall be made when about jo cc. of this material have distilled over. The distillation shall be stopped at this point, this combined fraction being Fraction C. It is generally necessary during t h e latter part of t h e distillation t o place a small flame under t h e oil bath t o t a k e care of loss of heat by radiation. The entire time for t h e fractional distillation should be about z hrs. mi,
,,,
l
,,
I
IO,
NO. 12
figure and t h e volume of t h e fraction. From these figures t h e total volume of benzol and toluol i n t h e original oil are determined. The toluol figure so obtained must of course be corrected for a n y pure toluol added before t h e fractionation. Correction for P a r a s n Hydrocarbons-If paraffin hydrocarbons are present in t h e original oil they will of course appear along with t h e benzol and toluol a n d their presence here can be corrected for. This correction is made b y determining t h e gravities of t h e three fractions, B, C and D, accurately a t I 5 . 5 O C. b y means of t h e Mohr-Westphal balance following t h e procedure of H4.l Assuming a specific gravity of 0.884 for pure benzol, 0.871 for pure toluol, and 0.869 for pure xylol, t h e theoretical gravity of t h e three fractions can be calculated as follows: 0.884 X per cent benzol f 0 871 X per cent toluol =
theoretical gravity of fraction
100
T h e specific gravity of t h e aliphatic hydrocarbons corresponding t o t h e three fractions would be, respectively, 0 . 7 2 0 , 0,730, and 0.740. The percentage paraffin in t h e fraction can now be calculated as follows: Theoretical sp. gr. of the fraction Actual sp. gr. of fraction Sp. gr. of corresponding aliphatic hydrocarbons Per cent aliphatic hydrocarbons in fraction
PER
CURVEI-TEST P10.
Cm"
~ ~ L U O L
= a
= b = c X 10 = a-6 a-c
T h e per cent paraffin so obtained must of course be corrected for i n t h e benzol and toluol figures.
DISTILLATION OF BENZOL-TOLUOL MIXTURES
Interpretation of Results-Ioo cc. portions of Fractions B and C shall be submitted t o distillation following t h e procedure of E4,temperatures being observed at s t a r t , j o per cent off, and dry. T h e distillation of Fraction B shall be made using a 70' C . t o IZOOC.thermometer, and t h e distillation of Fraction C using a 110' C. t o 160' C. thermometer. All temperatures shall be corrected for barometric reading, t h e correction factors for one millimeter of difference being as follows: Fraction B-o.04jo C . ; Fraction C-0.050~ C . Fraction A should contain no toluol and shall be regarded as benzol. Fraction B is a mixture of pure benzol and toluol with a very small amount of xylol. I t s composition shall be estimated by reading on Curve I , giving t h e boiling tests of benzol-toluol mixtures, t h e percentage of toluol corresponding t o t h e temperature a t which 50 per cent of t h e material was distilled off. The dry point of t h e distillation shall then be compared with t h e dry point curve of Curve z and t h e per cent xylol estimated. This percentage shall be deducted from t h e toluol. (This fraction should not contain more t h a n z per cent of xylol.) From t h e percentage composition of t h e fraction so obtained and from its volume t h e actual amount of benzol, toluol, and xylol in i t are figured. Fraction C shall be similarly distilled and t h e percentage of toluol in i t obtainedfrom Curve 2 by t h e temperature a t which 50 per cent was distilled off. This fraction should contain nothing b u t toluol and xylol. T h e actual amount of toluol is calculated from this
PREcAuTIoNs-care should be taken throughout all t h e operations t h a t proper precautions are taken t o prevent loss both i n distillation and i n handling. Corks should be tight and t h e distillate kept cool a n d covered as much as possible. For making cork connections, shellac is recommended. REPORTING RESULTS-AU results obtained are figured back t o t h e original oil as follows: Volume of constituent X 100 = per cent constituent Original volume of oil
THE BARRETTCOMPANY 17 BATTERYPLACE, NEW YORK
CITY
