Dec., :192o ExP'r. No.
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
....... .. ....
Wt 'sodium oxalate g... Temp. at start of rdn.. Vol catalyst soln used cc.. Vol: KMn04 requ'ired, &. Time for 1 c c . .
TABLEI1 1 062000 70
.. . 0 .. . . . . . . . ...... .. .. 33.90 1 min. (-1 Time for entire titration ..... . . Moderately rapid
2 0.2$00 22.5 0 33.87 4 min. 11 sec. 1 hr. (approx.)
0.2$00 22.5 22.5 5 10 33.85 33.85 1 min. 45 sec.
was taken for the entire titration, and was not so accurately observed as in the preceding experiment. Nevertheless, Table I1 shows a n effect similar t o t h a t already shown.
9 min. 6 min.
CONCLUSION
3 0.2$00
4
30 sec.
masses during the course of t h e process. I n this run the permanganate was added several drops a t a time with constant agitation, as rapidly as the solution cleared, each addition being made while the solution was still faintly pink. The acidity was about I per cent H2S04, but as it was not controlled as carefully as in the preceding case, and as this, as well as the mass of KMn04, affects the rate, the time for these runs
These experiments indicate t h a t the addition of MnS04 solution t o permanganate titrations is a practicable method of increasing reaction velocity, in t h a t the time of the peroxide-permanganate titration can by this means be reduced from about 3 5 min. t o 8 sec., and t h a t of the cold oxalate-permanganate titration from over a n hour t o 6 min. for the entire titration. The use of the catalyst does not affect the accuracy of the end-point.
LABORATORY .AND PLANT THE PRESERVATION OF BAGASSE IN SUGAR-CANE MILL CONTROL1 By Guilford L. Spencer CUBAN-AMERICAN SUGARCo., 129 FRONT ST., NEW YORK,N . Y.
container. The ammonia thoroughly permeates the bagasse, saturates the acids, and imparts a characteristic yellow color t o the sample. The analysis of the bagasse is conducted as usual, except t h a t no sodium carbonate need be added in the digestion, and the water extract must be acidulated with acetic acid prior t o clarification with subacetate of lead. I n comparative tests of finely comminuted bagasse, the samples were analyzed immediately, after storage with formaldehyde, and after storage with ammonia, for periods of 3 and 6 hrs. The formaldehyde sample showed a loss after 3 hrs. and a considerable loss after 6 hrs. The ammonia sample lost 0.1 per cent sucrose in 6 hrs. The sample originally contained 3 per cent of sucrose. Therefore, formaldehyde is not apparently a safe preservative for bagasse. It is the writer's expectation t o have made many comparative tests, using ammonia in preserving bagasse samples, with a view t o arriving a t more definite information. A combination of ammonia for saturating the plant acids and a n antiseptic for preventing fermentation is desirable. ' Preliminary experiments indicate t h a t bagasse may be preserved for periods of several hours in a n atmosphere of am.monia and chloroform. This is also effective in preserving filter press-cakes.
A review in the March 1920 issue of the International Sugar Journal, page 169,calls attention t o the deterioration of bagasse composite samples as regards sucrose content. I n this review two chemists report decomposition even in the presence of formaldehyde or chloroform, a n d a third chemist's experiments show no loss of sugar after 5 hrs. storage in a stoppered bottle without antiseptic. The writer began the use of formaldehyde as a preservative of samples in the laboratory, and of juices and meladura in the factory in the season of 1903 t o 1904 in Cuba. He abandoned its use except for very short storage periods for juices (I hr.) and bagasse ( 6 hrs.), on account of inversion of sucrose by the plant acids and not on account of ferments. At t h a t time, however, experiments indicated formaldehyde t o be a fairly safe preservative for bagasse for short periods. Formaldehyde is extensively used, and is without a rival in t h e protection of juice and meladura, during forced stoppages of the factory, though loss by inversion is known t o occur. It is possible t h a t the present very heavy milling with long trains of mills and with large use of maceration water, as compared with t h e conditions of a few years ago, may be in part THE SPECIFIC HEAT OF PETROLEUM AT DIFFERENT causes of the unsatisfactory results now obtained with TEMPERATURES' formaldehyde. By F. W. Bushong and L. L. Knight I n a.ccopnting for irregularities in bagasse tests, the RESEARCH LABORATORY, GULP REFININGCo., PORTARTHUR, TEXAS writer recefitly found these t o be due t o the inefficiency The work herein described was undertaken t o of formaldehyde in protecting the samples. There was usually no evidence of fermentation, and it is determine the rate of increase in the specific heat probable t h a t the loss of sucrose was due t o inversion. of petroleum with rise in temperature. The apparatus ThiS ked t o renewed experimentation with strong employed was the Parr standard calorimeter, which ammonia, as proposed and practiced in Egypt by the gave results of sufficient accuracy for technical work. The bomb was charged with benzoic acid, as recomlate Henri Pellet. The bagasse is collected in covered cans in a very mended for the standardization of the instrument, strong atmosphere of ammonia. Cotton, saturated and the oil or other liquid under examination was with strong ammonium hydroxide, is placed in per- employed as the calorimeter fluid. forated tin boxes a t the top and bottom of the bagasse 1 Presented before the Division of Industrial and Engineering Chem1 Presented before the Section of Sugar Chemistry at the 60th Meeting of the American Chemical Society, Chicago, Ill., September 6 to 10, 1920.
istry at the 59th Meeting of the American Chemicdl Society, St. Louis, Mo., April 12 to 16, 1920.
1198
T H E J O U R N A L OF IiVDUSTRIAL A N D ENGINEERING C H E M I S T R Y
Vol.
12,
No.
12
Dec., 1 9 2 0 0.4
T H E ,JOURNAL OF I N D U S T R I A L A N D ELVGINEERING C H E M I S T R Y 0.5
I
SF€C/F/C H€A T
I
0.6
+
04
2/20
I n determinations or standardizations made with t h e talorimeter Auid one or two degrees below room temperature, t h e calculations were made in accordance with t h e directions furnished with the calorimeter, At other temperatures it was necessary t o take into account t h e rates of radiation established before t h e ignition of t h e charge and after the maximum rise. These rates were laid off on coordinate paper against t h e observed rise, and t h e points representing them were joined by a straight line upon which one-minute intervals were laid off. The sum of t h e temperature values apportioned t o t h e minute interrals was applied as a radiation correction t o the observed rise. The specific heat was calculated as follows: Tke number of calories absorbed by t h e apparatus was 'ound b y multiplying t h e water equivalent ( I 2 3 . 3 9.) by t h e corrected rise. This was deducted from t h e heat generated in t h e bomb (4869 cal. in case of t h e usual charge), giving t h e number of calories absorb( d by t h e oil. By dividing this number by t h e corrected rise and by t h e weight of t h e oil (in grams), the specific heat was obtained. For t h e standardization of t h e method, water was employed u p t o 105' F. At higher temperatures t h e heat losses due t o evaporation of water were so great as t o introduce considerable errors. Similarly in making determinations below room temperature, errors due t o condensation were introduced. High viscosity is a n unavoidable source of error which cannot be neglected in t h e consideration of t h e results. Scniff has shown t h a t t h e effect of temperature upon specific heat is t h e same for organic liquids of t h e same
I
05 SPECIF/C
1199 0.6
I
HEAT
1
PI24
chemical nature, specific heat being a linear function of temperature. Curves representing t h e specific heat of t h e different members of a given class are, therefore, parallel straight lines. The results obtained by t h e method just described, together with those taken from chemical literature, are presented in the form of curves. They show t h a t the specific heat of t h e petroleum hydrocarbons, including paraffin, is proportional t o , DATAF O R FIG.1 Temperature
c.
1I 0 100
80 68 65 52 30 15 0
Water Sp. H t . 1.0116 1.0065 1.0024
,...
1.0000
....
0.9974 1,0000 1 ,0087
Liquid Paraffin Sp. H t .
.... 0.6307 0.5974 0.5798
....
0.5700
....
Ethyl alcohol 00 80'
c. C.
Sp. H t . 0.5475 0,7694
Isoamyl alcohol
c. c.
0.5012 0.7712
Glycerol 26.5' C. 6 8 . 0 ' C.
0.5523 0.6541
00
I000
Solid Paraffin Petroleum distillates-Mean1 0.4703 0 47 21.10 0 0.5420 0.43 0,535 6 8 , 0 ° C. -10 0.40 0.478 -20 F a t t y acids 0.375 0.450 -3 0 0.4440 0.35 00 c. 0.428 -40 0.5858 0.34 1000 c 0,409 -5 0 0.32 0.392 -60 F a t t y esters 0.31 0.374 -70 0.4416 0.30 00 c. 0.358 -80 0.5296 1000 c 0.29 0.341 -90 0.28 0.325 -100 Turpentine 0.27 0.307 -1 10 0.4110 00 c. 0.26 0.293 -I20 0.4414 330 c. 0.25 0.277 -130 0.4639 53' C. 0.24 0.262 -140 0.23 0.245 -150 Benzene 0.21 0.230 -160 0.4247 3 2 . 2 ' C. 0.20 0.215 -170 0.4449 52.2OC. 0.18 0.199 -180 Benzene and homologs 0.16 0 . I83 -190 0.4042 200 c. 0.14 0.165 -200 0.4668 0.12 80' '2. .... -210 1 This is t h e mean derived f r o m about 200 determinations on distillates obtained from t h e various oils examined by the authors. R a t e of increase 0.00153 per degree C . Ice ~~
,...
c.
