A w . , 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
t h a t t h e aqueous vapor must be t a k e n into account, there is nothing t o do b u t make t h e necessary corrections in each quantity a s found-which is more simple t h a n making a new set of equations. It seems t o be true, as first observed b y Berthelot,’ t h a t nitrogen trioxide is first formed b y t h e interaction of nitric oxide and oxygen even when t h e oxygen is in excess, b u t t h e nitrogen dioxide is so quickly formed t h a t there is no danger of error from this source. Only traces of nitric acid are formed a t t h e dilution of t h e gases used, though if pure oxygen and pure nitric oxide are mixed, larger quantities m a y result. These reactions in no way affect t h e titrations. and only t h e final volume as a small correction t o a large volume. I n experimental work t h e total ammonia consumed can be found b y titrating t h e liquor used for s a t u r a t ing t h e air (if t h e air is saturated b y this means) before a n d after t h e experiment. B u t this is of course impossible in a manufacturing plant, since t h e intake a n d exit gas are sampled only, not taken as a whole. For t h e nitrous acid, t h e most practical method for t h e case in h a n d is b y t h e use of permanganate. I n the procedure devised b y Lunge,2 t h e nitrous acid sample is placed in t h e burette a n d r u n into a measured excess of permanganate heated t o 40-50’. T h e color change is not very prompt, a n d t h e method is inconvenient unless the approximate a m o u n t of nitrous acid is known. B y working in t h e following way t h e results are obtained more quickly, t h e approximate q u a n t i t y of nitrous acid need not be known, andwhat is a matter of importance in some plants-no flame or heat is required. Prepare a dilute solution (about I volume of 3 yohydrogen peroxide t o 7 volumes of water) a n d t i t r a t e i t with permanganate. d d d a measured quantity, s a y I O cc., of this solution t o t h e nitrous acid sample, a n d t i t r a t e with permanganate. T h e nitrous acid is readily calculated from t h e difference. E v e n if t h e hydrogen peroxide had t o be titrated for every determination, t h e method is more satisfactory t h a n t h e direct use of permanganate. Of course t h e same assumptions are valid as t o t h e presence of other oxidizable bodies, etc., as with t h e direct use of permanganate. 1605 EASTCAPITOL ST. WASHINGTOS, D. C.
THE EFFECTS OF EXPOSURE ON SOME FLUID BITUMENS By CHARLESS. REEVE AWD RICHARDH. LEWIS Received April 16, 1917
I n 1912, Hubbard and Reeve published a paper3 giving t h e results of exposure on some semi-solid bitumens, a n d this was later followed b y a paper4 b y Reeve a n d Anderton in which t h e effects of exposure Compt. r e n d . , 67 (1873), 1450. “Sulfuric Acid and Alkali,” 4th E d , 1 (1913), 3 8 i . See also especially Gerlinger, Z . angew. Chem., 1901, p. 1250. 8 “The Effect of Exposure on Bitumens,” THISJOURXAL, 6 (1913), 15. A paper presented a t the Eighth International Congress of Applied Chemistry, New York, September, 1912. “ T h e Effects of Exposure on T a r Products,” J . Frank. Inst., October, 1916. 1
* Lunge,
’
743
as limited t o t a r products were shown a n d some of t h e relations between t h e results of exposure a n d laboratory tests were discussed. I n view of t h e interesting behavior shown b y t h e various products considered in t h e above investigation, t h e authors felt t h a t further results of value might be brought o u t b y continuing a similar line of investigation t o show t h e behavior of more fluid materials. T h e form of investigation is, moreover, more directly related t o materials of this character, owing t o t h e fact t h a t t h e y are largely used in surface treatment where t h e y are directly exposed in a thin layer t o t h e action of sun and air. T h e exposures were made in a box of t h e same t y p e as t h a t used in previous work and shown in Fig. I.
FIG. I
For t h e information of those who are not familiar with t h e earlier publications on t h e subject, t h e following brief description of this box is given. It is made of 3/4-in. wood and has interior dimensions 2 j X 14l/2 X 2 in. A ‘/d-in. plate glass cover rests on a strip of thick felt fastened t o t h e edges of t h e box in order t o make a tight joint and exclude all dust. For ventilation, slots are cut through each side of t h e box, and t o prevent t h e entrance of rain these are protected b y a thin board extending from t h e rim a t an angle of about 45’. Cotton batting is packed under this board against t h e slots t o exclude dust from t h e outside air. T h e samples t o be exposed were placed in 2 - 0 2 , , seamless, flat-bottom, tin boxes, having a diameter of 6 cm. and a depth of 2 cm. I n order t o insure a uniform depth of sample, approximately 1 2 cc. of t h e material under test were used. Seven rows, each consisting of six boxes of t h e same material, were placed lengthwise of t h e box, which was set with its long side extending east and west outside a window having a southern exposure. T h e m a t e r i d s used and their characteristics are given in Table I. All tests made in connection with this work v e r e carried out as described in Office of Public Roads Bidleti?i 38.’ T h e samples were exposed on J a n u a r y 7 , a n d a t t h e end of every second month a complete set ~ 7 a s withdrawn a n d tested, until t h e exposure had r u n throughout a full year T h e tests a t t h e end of each period included a careful weighing t o note a n y loss or gain, a consistency test, and t h e determination of organic matter insoluble in carbon disulfide, and fixed carbon. Where possible, penetration tests were made on t h e residues from exposure; othenvise, t h e consistency was determined b y a float test a t 40’ C. f “Methods for the Examination of Bituminous Road Materials,” b y Prevost Hubbard and Charles S. Reeve
744
T H E J O U R N A L OF I N D r S T R I A L A N D EiVGINEERING C H E M I S T R Y OP PETROLEUM PRODUCTS USED IN TESTS CRUDE PETROLEUM OIL-ASPHALT Mexican Trinidad CUT-BACK 6320 6335 6122 6121 0.926 0.947 0.958 0.937 27 32 155 172 46 68 173 195 41.5 ( 2 5 ' C.) 88.1 (25' C.) ,(;p:,C.) 49.8 (25' C.)
Vol. 9 , No. 8
TABLEI-ANALYSES Sample Number Specific gravity 25/25' C.. Flash point, C.. Burning point, C.. Specific viscosity
................ ........................ ..................... .........................
Float test, 40' C. .............................. Per cent loss, 163' C., 5 hrs.. 27.19 Consistency of residue(a). 6' 0" Bitumen soluble in CSg 99.97 Organic matter, insoluble. . . . . . . . . . . . . . . . . 0.03 Inorganic matter, insoluble.. . . . . . . . . . . . . . . 0 . 0 0 Per cent bitumen insoluble in 86' BB. naphtha 12.79 7.23 Fixed carbon ............................ ( a ) Float tests at 40' C. WATER-GASTARPREPARATION, ,,,,, Sample Number 6321 Specific gravity 25'/25' C.. .......................... Specific viscosity 50' C.. ............................. Float test, 40' C.. .................................. Free carbon ........................................ Loss a t 163' C., 5 hours.. ........................... Penetration residue.. ...............................
,?!.!
1JJ.I
.............. . .................. ................
4.84
4.12
............................ 1.126 29.8 2 2 . 4 secs. 2.4370 19.27% 1 0 . 6 mm.
Table I1 gives the results which show t h e changes for each period a t which samples were withdrawn from t h e exposure box. It will be noted t h a t a t t h e end of two months t h e crude petroleums had lost 12.47 per cent and 14.57 per cent, respectively; t h e two cut-back products had each shown a slight increase in weight, while t h e Texas residual petroleum (6336) had shown a decided increase in weight, 2.16 per cent, a n d slight softening of t h e material as indicated b y t h e float test a t 4ooC. It is interesting t o note t h a t t h e t a r preparation (6321), which on distillation gave less t h a n 2.1 per cent distillate t o 170' C., lost 7 . 2 9 per cent during t h e two coldest months of t h e year. T h e four materials above discussed were all used i n adjacent experimental sections for t h e surface treatment of a limestone macadam road, so t h a t a comparison of service with test results is possible. The treatments were applied simultaneously in t h e late fall when t h e conditions for a rapid setting u p of t h e materials were about a t their worst. T h e applications were covered with pea gravel. The behavior of t h e four products was in general accord with their relative behavior as shown in Table 11. T h e crude
(LJ
13.8" 9.79 1' 5 " 99.92 0.08 0.00 11.55 6.81
PETROLEUM RESIDUUM Texas Trinidad 6336 5857 0.957 167 198 4 3 . 0 (50' C.)
0.994 107 173 17.3 (100' C.)
L.J
12.9" 6.32 18" 99.92
1.22" 12.03 6' 30" 99.82 0.10 0.08 9.51 5.63
0.05
0.03 0.65 1.47
Distillation Test Dimathyl S u l f a t e Test Per cent b y Per cent Insoluble . Weight . Light Oils t o llOo C.. .... 0 . 5 ( a ) Fraction 110 t o 170' C .......... 1.6(b) 270 t o 315' C 7.5 Heavy Oils: 315 t o 350' C ........ 10.0 170 t o 270' C.. . . . . . . . . 18.8(c) 350 t o 375' C... . . . . . 7 . 5 270 t o 315' C.. ........ 1 3 . l ( a ) Pitch Residue.. . . . . . . . . . 65.9 ( a ) Clear. ( b ) Cloudy. (c) Slightly cloudy.
........
petroleums a n d the t a r preparation soon developed a firm mat which withstood rain a n d snow under traffic without displacement or disintegration. T h e Texas residual petroleum (6336), however, rapidly worked into a deep mud in wet weather, a n d although it soon ironed out under fair weather conditions, it s h o w e d . the same tendency t o break u p in rainy periods throughout the year. I t will be noted t h a t this particular product showed no material hardening in t h e exposure box a t t h e end of a year as compared with t h e other three materials. Referring again t o Table 11, it will be seen t h a t all the materials show a consistent loss a n d hardening for IO months. Penetration tests were possible on t h e two crude petroleums, t h e Trinidad petroleum residuum, and the water-gas t a r preparation a t t h e end of 4 months. T h e other materials remained fluid throughout t h e year, although t h e oil-asphalt cutback (6122) behaved in a peculiar a n d interesting manner. After four months, this material separated into two distinct layers-a fairly greasy fluid above a n d a hard, brittle deposit on t h e b o t t o m of t h e can. By heating gently a n d constantly stirring, a uniform mixture for testing was obtained a t t h e end of four
TABLE11-CHANGES IN MATERIALSON EXPOSURE IN B o x IN CONSISTENCY: NOTE.-Where consistency is indicated in units of time, results are float tests a t 40° C.; when no indication accompanies the figures, they represent penetrations a t 2.5' C. (100 grams, 5 seconds). T h e melting point (Cube method) is included in tests on t a r residues. ORIGINAL 2 months: March 7 4 months: M a y 7 6 months: July 7 8 months: Sept. 7 10 months: Nov. 7 12 months: Jan. 7 Specific Float Per cent ConsisPer cent ConsisPer cent ConsisPer cent ConsisPer cent ConsisPer cent ConsisNo. Viscosity test 40' C. Weight tency Weight tency Weight tency Weight tency Weight tency Weight tency 6320 41.5 (25' C.) ... -12.47 37.2" -23.72 173 -25.57 99 -27.50 30 -26.44 40 -27.62 41 6335 88.1 (25' C.) ... -14.56 53" -23.43 68 -24.96 35 -26.35 14 -26.60 31 -25.63 13 6122 49.8 (25' C.) ... +0.79 8.6" -7.04 22" -11.34 { ~ ~ ~ ~ -15.00 ~ t e d ) -16.80 ... -14.21 6121 13.8" 1 0 . 7 6 16.2" -2.65 26" -5.86 39' -9.00 43" -9.57 50" -8.20 40" 1 J J . l \ L J ~L.1 6336 43.0 (50' C.) 12.9" +2.16 7.8" -3.30 24" -6.20 48" -8.38 1' 8" -9.42 1' 19" -9.90 58" 5857 17.3 (100' C.) 1' 22" +0.18 1' 12" -6.09 83 -8.11 28 -9.29 14 -9.36 14 -8.09 16 -7.29 1' 11" -20.94 41 -24.92 11 -27.38 3 -27.34 2 -26.32 4 6321 29.8 (50' C.) 22.4" M . P. 54' C. M . p. 77' C. M . p. 78O C. M . p. 82' C. M . p . 78' C PERCENTAOE CHANGEIN INSOLUBLE ORGANIC MATTER(U) : 2 months 4 months 6 months 8 months 10 months 12 months Original NO. value Actual Calculated Actual Calculated Actual Calculated Actual Calculated Actual calculated ~ ~ calculated t ~ 6320 12.65 4-6.06 +1.57 +16.39 +2.99 +17.98 4-4.34 +21.12 +4.94 +21.66 +4.80 C20.39 $4.53 6335 8.88 +7.57 +1.29 +12.60 +2.08 125.73 +2.9j +31,34 +3.17 1-31.27 +3,22 +29.29 +3,04 6122 8.19 -0.05 -0.06 f3.16 +0.58 +6.75 f1.05 +10,86 f1.60 +13,10 f1.65 +12,65 +1,36 6121 11.55 +1.02 -0.09 3.80 +0.30 5.07 +0.72 + 8.56 +1.14 + 8.68 1-1.22 + 7.27 11.03 6336 0.65 4-0.96 -0.01 5.60 +0.02 7.88 +0.04 +12.92 +0.05 f 1 3 . 4 3 1 0 . 0 6 +11.92 +0.07 5857 9.51 +5.08 -0.02 +18.01 +0.58 +23.08 t0.73 +28.69 f0.85 +27.88 +0.94 1-28.75 10.85 6321 2.43 4-2.08 10.18 6.51 +O.Sl 8.77 1-0.81 +11.52 +0.92 +12,24 +0,92 + 9.82 + 0 , 8 7 PERCENTAGECHANGEOF FIXEDCARBON: 7.23 +1.80 4-1.03 4.05 12.23 4.51 +2.48 5.88 4-2.75 , 4.99 1-2.74 5.35 +2.64 4.84 +1.76 +0.82 2.93 +1.48 4.71 +1.61 5.67 +1.75 5.80 +1.76 5.24 11.65 4.12 -0.61 1.37 -0.04 +0.21 1.57 +0.52 2.32 4-0.74 2.98 2 . 2 5 + 0 . 8 3 +0.68 6.81 + O . 14 -0.05 0.33 + O . 18 1.85 + O , 42 2.07 +0.67 1.86 +0.72 1.67 +0.61 1.47 +0.47 -0.04 0.78 +0.05 1.49 +0.10 2.21 +0.13 2.32 2.35 +0.15 +0.18 5.63 4-0.91 -0.01 4- 2.43 4-0.36 4- 4 . 2 7 + 0 . 4 9 4- 4.60 +0.57 4.59 +0.58 5.11 1-0.49 ( a ) No. 6321 d a t a for "Insoluble in Carbon Disulfide," others for "Insoluble in 86' BC. Petroleum Naphtha." CHANGES IN WEIGHT A N D
...
.?!.! (22: s.?
+ + + + + + + +
...
++
+
++ + ++
++ + + +
+
+ +++ +
+ + + + + +
~
l
Aug., 1917
.
T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
TABLE111-CHANGES ON 163’ C. VOLATILIZATION PER CENT L O S S AND CONSISTENCY OD RESIDUE PER CENT GAININ INSOLUBLE ORGAbIC MATTER((L) PER CENT CHANGES I N FIXEDCARBON -5 HOURS-- -10 HOURS- -15 HOURS-5 HOURS-10 HOURS- -15 HOURS-5 HOURS-10 HOURS- -15 HOURSLoss Consis- Loss Consis- Loss ConsisNo. % tency Yo tency % tency Orig. Actual Calc. Actual Calc. Actual Calc. Orig. Actual Calc. Actual Calc. Actual Calc. 13.85 +5.18 4-16.80 f5.81 7.23 +4.39 +2.10 +5.10 +3.00 +5.69 f3.37 6320 27.19 6 ’ 0 “ 29.39 190 31.81 98 12.65 1.11.63 +4.64 4’46”28.31 242, 31.05 116 8.95 +3.07 +10.74 $3.50 +13.36 +4.00 4.84 +3.73 +1.67 +4.30 4-1.91 f 4 . 8 1 +2.18 8.88 6335 25.69 0.99 +1.14 3.31 +1.97 8.19 6122 13.29 22:-, 19.50 1 26.16 1’40” 6.69 4-2.90 4.12 f 0 . 3 5 +0.64 3-1.33 +0.99 -2.53 +1.46 11.55 3.85 +1.25 7.23 +2.25 6121 9.79 1 3 16.30 5;, 18” 17.47 15’+ 8.68 +2.44 6.81 +1.36 +0.74 +2.09 1.93 +2.69 +1.41 15.42 32” 0.65 0.66 +0.04 f 1.68 i-0.10 13.02 27 6336 6.32 18” 2.00 f 0 . 1 2 1.47 +0.5/ +O.lO +l.!l +0.22 +1.33 +0.27 6.54 +1.30 8.13 f 1 . 4 8 f10.77 +1.70 5.63 +2.02 +0.73 f 2 . 1 8 +0.88 + 3 01 +1.02 9.51 15.36 117 5857 12.03 6’30” 13.50 188 6.68 f 1 . 0 6 5.39 +0.58 , . .. .. .. .. . . .. 2.43 31.19 1 7.49 +1.10 . . .. 8 3 6321 19,27 106 Ig.7p.75.8O C. M. p. 78.6’C.
.
++ + +++
+ ++ ++
++ + +
+
..
..
..
....
( a ) No. 6321 data for “Insoluble in Carbon Disulfide,” others for “Insoluble in 86O Be. Petroleum Naphtha.”
months, b u t after this t h e components of t h e sample could not be sufficiently well mixed t o yield consistency test results of a n y value. The sample, in fact, behaved in a manner somewhat similar t o a n a p h t h a insoluble determination, due, no doubt, t o t h e fact t h a t t h e asphalt used was cut or thinned with a distillate t o which i t was not closely allied. T h e results on t h e two cut-back products are particularly interesting from t h e fact t h a t they show conclusively t h a t such products, when fluxed with high-boiling distillates, as were those under test, cannot be expected t o lose their volatile matter a n d develop a firm binding material under exposure. The results also serve as a refutation of claims made for t h e great value of t h e “per cent of asphalt” test, which consists in determining t h e a m o u n t of resid u e of a given penetration obtained by evaporating t h e sample a t a high temperature. A temperature as high as 260’ C. (500’ F.)is quite generally permitted in making this test, a n d petroleum products of t h e character represented b y our Samples 6121,6122 a n d 6336 will yield from 40 t o 50 per cent of residue of I O O penetration. It is evident, however, t h a t t h e high-boiling distillates driven off a t a high testing temperature are not driven 08 under t h e exposure conditions of service, a n d t h e test is therefore not a correct measure of t h e value of t h e material. I n reviewing t h e results for 1 2 months’ exposure, i t will be seen t h a t all t h e samples excepting No. 6336 showed a lower loss t h a n a t t h e previous period or even 8 months’ period, a n d t h e two residues on which float tests were made showed a slight increase in fluidity. A thorough consideration of all details of t h e work yields no explanation t h a t would make a n y error in details of t h e work responsible for these results. It has been shown in previous papers, referred to, a n d will be again demonstrated through d a t a t o be discussed later t h a t changes other t h a n those due t o volatilization occur in bituminous materials exposed t o atmospheric influences. Such changes may be responsible for t h e results obtained a t t h e later periods in t h e present work, in t h a t these later periods extended through cold weather when t h e volatilization with residuals t h a t had been exposed through hot weather would materially diminish or cease, b u t reactions due t o oxidation or other additive processes might continue. I n Table I1 t h e calculated percentages of insoluble organic matter represent t h e increase or decrease which would be brought about b y t h e loss or gain reported in t h e same table. A detailed discussion of these results is perhaps unnecessary, but, as shown b y
Hubbard and Reeve‘ in their work on harder bitumens, t h e increase in insoluble organic matter is f a r in excess of what i t would be from mere volatilization of lighter constituents. This increase ranges from 7 times t h e calculated amount in t h e case of t h e oilasphalt cut-back (61z I ) t o I 70 times t h e calculated amount in t h e Texas petroleum residuum (6336) a n d of particular interest i n t h e latter case is t h e fact t h a t this increase was attended with but, relatively immaterial hardening of t h e sample. Table I1 also gives t h e percentage change i n fixed carbon for each period of exposure, compared with t h e calculated changes based on t h e loss in weight of t h e sample. As with t h e bitumen insoluble in napht h a , t h e fixed carbon shows a marked increase over what could be accounted for b y loss of volatile constituents. Attention was called above t o t h e fact t h a t as compared with previous results all b u t one of t h e samples showed a slightly decreasing loss a t 1 2 months, a n d i t will be noted t h a t most of t h e samples show a recession in t h e percentage of insoluble organic matter and fixed carbon which had been previously present. This phenomenon is too consistent t o be attributed t o errors i n determinations, a n d would appear t o be due t o what are a t present inexplicable changes in t h e bitumen. I n order t o compare t h e effects of volatilization in laboratory testing with those obtained upon exposure, all t h e materials were subjected t o t h e volatilization test’ for 5-hour periods on 3 successive days, a n d tests were made on residues a t t h e end of 5, IO, a n d 1 5 hours, respectively. The complete results are given in Table I11 and they clearly show t h a t heating a t 163’ C. for even 5 hours produces changes in t h e material t h a t cannot be accounted for by mere loss of volatile matter, although these changes are not as great as those produced through exposure t o sun a n d air. I n order t o compare more readily t h e results of exposure with those of laboratory methods, separate tables have been prepared which embody the d a t a of particular interest. I n Table IV, for instance, results have been selected in which either t h e loss or consistency of t h e residue obtained by each method are nearly identical in order t o shorn t h e difference in t h e other factor. I t is shown t h a t t h e loss b y volatilization a t 163’ C. for 5 hrs. approximated t h e loss on exposure a t t h e periods given in t h e case of Nos. 6320, 633j, 6 1 2 1 a n d 6336, b u t t h e residues in each case, excepting No. 6 1 2 1 , were harder after exposure t h a n after t h e volatilization test. This is particularly noticeable in t h e case of t h e two crude
’ LOC. C i t .
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I X G C H E M I S T R Y
746
.Vol. 9, No. 8
TABLEIV-SELBCTED DATAFOR COMPARISONS OF RESULTS INCREASESIN ORGANIC MATTERINSOLUBLE INCREASES IN FIXED CARBON -Volatilization 1 6 3 O C.-Exfioswe-Volalilisafion 163’ C.-Exfiosure-Volatilization 163 C.-Ezfioswe-Loss ConsisLoss ConsisINCREASE INCREASE VALUE VALUE NO. Hrs. Per cent tency Mo. Per cent tency Hrs. Calc. Actual M o . Calc. Actual Hrs. Calc. Actual Mo. Calc. Actual 6320 ...... 5 27.19 6’ 0” 8 27.62 41 5 4 . 6 4 11.63 6 4 . 3 4 17.98 5 2.10 4.39 4 2.23 4 . 0 5 15 31.18 98 6 25.57 99 10 5 . 1 8 13.85 8 4 . 9 4 21.12 10 3 . 0 0 5 . 1 0 10 2 . 7 4 5 . 9 9 6335.. 5 25.69 4‘ 46” 6 24.96 35 5 3.07 8.95 6 2 . 9 5 25.73 5 1.67 3 . 7 3 6 1.61 4.71 10 28.31 242 10 26.60 13 10 3 . 5 0 10.74 10 3 . 2 2 31.27 10 1.91 4 . 3 0 10 1 . 7 6 5 . 8 0 13.29 22” 4 7.04 22” 5 1.14 0.99 6 1.05 6.75 6122.. , , , 5 5 0.64 0.35 6 0 . 5 2 1.57 10 0 . 9 9 1 . 3 3 10 0 . 8 3 2 . 9 8 1, 5 ” 9.79 6121 . . . . . . 5 10 9.57 50” 5 1.25 3.85 10 1.22 8.68 5 0 . 7 4 1.36 10 0 . 7 2 1 . 8 6 6336 . . . . . . 5 6.32 18: 6 6.20 48” 5 0.04 0.66 6 0.04 7.88 5 0.10 0.57 6 0 . 1 0 1.49 10 13.02 27 4 3.30 24“ 15 0 . 1 2 2.00 10 0 . 0 6 13.43 15 0 . 2 7 1 . 3 3 12 0 . 1 8 2 . 3 5 5857 15 15.36 117 4 6.09 83 5 1.30 6.54 8 0 . 8 5 28.69 5 0.73 2.02 10 0 . 5 8 4 . 5 9 6321 5 19.27 106 4 20.94 41 5 0.58 5.39 4 0.51 6.51 .......... 10 30.78 3 8 27.38 3 15 1 . 1 0 7.49 8 0 . 9 2 11.52 LOSS AND CONSISTENCY O F RESIDUES
-
....
.
...... ......
.......... ..........
..........
petroleums (Kos. 6320 and 6335), in which t h e resi- more pronounced t h a n those obtained in t h e routine dues from volatilization were too fluid for a penetra- laboratory test. tion test, while after losing approximately t h e same The above d a t a corroborate a n d amplify all amount on exposure they yielded residues having previous d a t a t o t h e effect t h a t bituminous materials penetrations of 41 a n d 35, respectively. Samples upon exposure undergo changes t h a t are due t o some6320 a n d 6122 also offer interesting comparisons, thing more t h a n mere loss of volatile matter. Such since t h e consistencies in two instances are identical. changes occur in samples when subjected t o t h e volaI n t h e case of t h e first material, however, i t required tilization test in a laboratory oven, although t h e changes a loss of 3 I . 81 per cent b y volatilization i n a n oven are greater when t h e exp0sure.k made under atmospheric t o produce a residue of t h e same consistency as t h a t influences. These changes differ in both character obtained through a loss of 2 5 . 5 7 per cent on exposure, a n d degree with different types of fluid bitumens, as while in t h e case of Xo. 61 2 1 i t required losses of 13. 29 would be expected from our knowledge of t h e varying a n d 7 . 0 4 per cent t o bring about t h e same result. chemical character of bituminous materials. Hubbard T o show t h e relation between t h e increase in actual and Reeve in reviewing their work on semi-solid overcalculated organic matter insoluble in samples bitumens indicated t h a t t h e increase in insoluble tested b y laboratory methods a n d exposure, samples organic matter might be due to oxidation, and t h a t for comparison were selected a t periods when t h e cal- t h e products might actually contain oxygen or be t h e culated increases based on t h e loss in weight were result of nucleus condensation brought about by t h e approximately equal. It is shown t h a t in practically reaction of oxygen with two or more hydrocarbons every instance t h e increase in organic matter as a re- originally present in t h e bitumens. The conclusions sult of exposure is several times greater t h a n t h a t pro- in t h a t case were based almost entirely on t h e results duced through heating in a laboratory oven. The of atmospheric exposure, while in t h e present d a t a Texas residual petroleum (No. 6336) shows t h e most t h e authors have included results obtained through noticeable differences b y t h e two methods where t h e t h e laboratory routine volatilization test. T h e fact calculated increase for 6 months’ exposure is identical t h a t t h e organic matter insoluble also increases mawith t h a t for 5 hours in t h e oven, whereas t h e actual terially in a closed oven where t h e changes of oxidaincrease b y t h e former method is 1 2 times t h e actual tion are reduced t o a minimum, would tend t o indiincrease obtained in t h e oven-heated sample. The cate t h a t other causes might be responsible for t h e t w o Trinidad products (Nos. 6335 a n d 5 8 j 7 ) also changes which occur. While oxygen plays its part show similar marked differences in t h e increases ob- in t h e changes which occur, t h e authors are led t o t h e conclusion t h a t polymerization a n d intermolecular tained by t h e two methods. It will be noted t h a t t h e oil-asphalt cut-back KO. reactions induced b y heat a n d possibly increased b y 6122 offers t h e only instance in which t h e actual in- t h e action of light are also very largely responsible for crease was less t h a n t h e calculated. This occurs in such changes, in addition t o those which are accounted t h e residue from t h e 5-hour volatilization and t h e sam- for b y simple evaporation. OFFICEOF PUBLICROADSAND RURALENGINEERING ple shows a similar peculiarity in t h e results of fixed WASHINGTON, D . C. carbon increases which were selected on a similar basis t o t h a t adopted for t h e other groups in Table THE OXIDATION OF MINERAL OILS BY AIR IV. T h e d a t a show t o some extent t h e same rela- I-THE EFFECT OF SULFUR ON THE OXIDATION OF tions between t h e results of oven a n d atmospheric HYDROCARBONS WITH PARTICULAR REFERENCE exposure, although t h e differences between t h e fixed TO ASPHALT carbon increases are not as marked as those €or orBy BENJAMIN T. BROOKSAND IRWIN w. HUMPHREY ganic matter insoluble. Received May 15, 1917 It has sometimes been contended t h a t t h e volatilIt has long been known t h a t on heating sulfur and ization test a t 163’ C. was too severe, a n d t h a t it paraffin, hydrogen sulfide is evo1ved.l Lidoff2 made subjected materials under test t o changes t h a t would hydrogen sulfide b y adding a petroleum “naphtha” t o not occur under ordinary conditions of exposure. hot sulfur a t 350’ t o 400’ C. a n d in 1892 Dubbs obT h e results above cited show t h a t such a n assumption tained a patent in t h e United States for a process of is not altogether well taken, a n d t h a t as a matter of 1 Galletly, Chem. N e w s , Z4 ( 1 8 i l ) , 162. 2 Chem. Zentr., 1882, 22. fact t h e effects of atmospheric exposure are much
