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 N G C H E M I S T R Y
890
8 5 . 8 4 per cent C and 13.99 per cent H
The residual oil of t h e 300 t o 302' fraction (after separation of t h e ozonide) was refined b y means of liquid sulfur dioxide, according t o t h e method of Ede1eanu.l T h e oil t h u s refined, washed a n d dried, h a d t h e refractive index 1.4712 a t 14', a n d was found t o contain 8 5 . 4 2 per cent C 8 5 . 6 2 per cent C
Calculated for C,H,,
1 4 . 1 2 per cent H 1 4 . 3 8 per cent H
T h e oil extracted therefrom b y t h e liquid sulfur dioxide, after washing, etc., h a d t h e refractive index 1 . 5 2 2 2 a t 1 6 ' a n d contained 8 2 . 4 2 per cent C
10.31 per cent H
7 . 2 7 per cent 0 (dif.)
T h e 296 t o 298' fraction, weighing 58.34 g. after t r e a t m e n t with sodium, a n d filtration, was treated in t h e cold with ozonized air for five successive days. T h e ozonide was washed with a b o u t 2 5 cc. of light gasoline, t o which it gave only a slight color. After evaporation of t h e residual gasoline in a current of per n a t u r a l gas there remained 5.8 g. of ozonide-Io cent of t h e weight of oil. Some of this ozonide was treated with anhydrous ether, yielding a red colored solution, which was poured off from a brick-red insoluble powder. After t h e evaporation of t h e ether there remained a transparent red s y r u p which hardened slowly like a varnish. A portion for analysis was spread in a film over t h e inner surface of a porcelain boat a n d dried in a desiccator. Its weight became constant a t 0.4122 g. On combustion this gave 0.9623 g. COZ a n d 0.2336 g. H 2 0 . Found 6 3 . 6 7 per cent C 6 . 3 4 per cent H Calculated for CirHzoOa 6 3 . 7 2 per cent C 6 . 3 0 per cent H 2 9 . 9 8 per cent 0
This is in accordance with t h e results obtained b y Molinari a n d Fenaroli2 with distillates from Roumanian a n d Russian petroleums. T h e 2 5 2 t o 254' fraction-the largest of t h e upper kerosene-after drying over sodium, was refined with liquid sulfur dioxide. A-The refined oil h a d a specific gravity of 0.8240 Its a t 15' a n d t h e refractive index 1.4660 a t 15'. composition was found t o be 85.29 per cent C
1 3 . 9 8 per cent H
B-The sulfur dioxide extract, after washing, etc., had t h e refractive index 1.5412 a t 12' a n d t h e composition Calculated for CISHzo
8 8 . 9 4 per cent C 10.19 per cent H 0.87 per cent 0 (dif.) 10.07 per cent H
89.93 per cent C
This extract, B, was t h e n treated with ozonized oxygen, in t h e cold. It yielded a n ozonide which when freshly precipitated was flaky a n d almost white, b u t slowly resinified. It was t a k e n up in absolute ether a n d shaken with successive portions of a dilute aqueous solution of potassium hydroxide until freed from acids. It was t h e n washed, a n d dried over calcium chloride. After evaporation of t h e ether a thick resinous s y r u p remained. 0.4681 g . of t h e d r y substance gave 1 . 2 7 1 2 g. COz a n d 0.2884 g. HzO. Found Calc. for ClsHlaOs
7 4 . 0 6 per cent C 7 3 . 7 3 per cent C
6 . 8 9 per cent H 6 . 6 1 per cent H
19.66 per cent 0
Molinari a n d Fenaroli isolated from t h e petroleum 1
U. S. Pat. 911,553. Feb. 2, 1909; Chcm. Abs.. 8, 1082.
* Bcrichtc, 41 (1908). 3407.
Vol. 6, No.
11
of Velleja, Italy, a flaky white ozonide having t h e composition C15H1606, which t h e y believe t o have been formed from t h e hydrocarbon C1bH16 b y t h e addition of t w o 0 3 groups t o t w o double bonds. Possibly our original product also may have been t h e same double ozonide, which on t r e a t m e n t with alkali lost half of its oxygen. I n t h e excellent work "Wissenschaftliche Grundlagen der Erdolbereitung," b y Dr. L. Gurwitsch, Berlin, 1913, pp. 34-35) t h e significance of t h e suggestion of hlolinari a n d Fenaroli regarding t h e preexistence of hydrocarbons of t h e series in kerosene is critically discussed, a n d i t is pointed o u t t h a t oxidation may precede t h e ozonide formation. T h e analysis of t h e sulfur dioxide extract of t h e unoxidized 2 5 2 t o 254 ' fraction shows approximately t h e same hydrogen content as t h e hydrocarbon Cl6Hza. Since, however, t h e extraction method cannot effect complete separation of t h e t w o classes of hydrocarbons i t is very probable t h a t this extract may consist essentially of t h e hydrocarbon C15H16, contaminated by small residual quantities of ordinary naphthenes. T h e ozone reaction has given us a valuable working tool for detecting new constituents of petroleum. T h e extraction method of Edeleanu enables us t o remove these constituents from t h e main body of t h e petroleum, in concentrated form a n d apparently unaltered condition. I n t h e opinion of t h e writer, however, t h e proof of t h e chemical composition of these reactive constituents awaits t h e development of a n independent method of attacking t h e problem. 3447 PARKVIBW Arm. PITTSBURGH, PA.
EFFECT OF PRESSURE ON YIELDS OF PRODUCTS IN THE DESTRUCTIVE DISTILLATION OF HARDWOOD By R. C. PALMER Received August 5, 1914 INTRODUCTION
A s t u d y of t h e effect of pressure on yields was conducted a t t h e Forest Products Laboratory a s a p a r t of a series of experiments t o devise methods of increasing t h e amounts of valuable products obtained in t h e destructive distillation of hardwoods. It is generally known t h a t certain primary reactions occur in t h e action of d r y heat on wood substance in t h e absence of air, resulting i n t h e primary products: acetic acid, methyl alcohol, a very complex t a r , charcoal, a n d such gases as carbon dioxide, carbon monoxide a n d methane. From a theoretical standpoint, i t is possible t o produce secondary reactions between these primary products such a s zCH3COOH = CH3COCHa C02 HzO, resulting in a decrease in CH,COOH = CH3COOCH3+ acetic acid, or CHaOH HzO, giving a decrease in both alcohol a n d acetic acid. T h e decomposition reactions of wood which result in t h e formation of t a r are a t present too little understood even for speculation b u t undoubtedly a relation exists between t h e t a r a n d charcoal, both products containing a high carbon content,' a n d a relation between acid or alcohol a n d t a r is certainly not impossible
+
1 Ultimate
+ +
analysis of birch tar has been given as CaeHaOis.
Arch. j . Kemic Min. and Geol.. Vol. 6, No. 7.
Rlason.
NOV.,
I914
T H E J O C R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
METHOD O F M A K I N G EXPERIMENTS
APPARATUS--k diagrammatic sketch of t h e app a r a t u s used is shown in Fig. I . T h i s a p p a r a t u s is a cast iron autoclave with n-alls I inch thick t o withs t a n d high pressure. T h e autoclave has a jacket
use of small material because of difficulties in heating were avoided b y stirring t h e charge. Also while probably not commercial in t h e ordinary types of distilling apparatus, sawdust or chips served t h c purpose of obtaining simply comparative results. The different kinds of material were first distilled a t atmospheric pressure under conditions as far as possible comparable with t h e ordinary methods of commercially distilling wood. Distillations were then made under different pressures u p t o 1 5 0 lbs. per s q . in. I n t h e pressure distillations as soon as t h e first water distillate was coming in sufficient quantity t o insure t h a t all air h a d been displaced t h e outlet was closed until t h e desired pressure was obtained as indicated on a pressure gauge, t h e outlet then being opened just enough t o maintain t h e pressure. I n most cases very little manipulation of t h e outlet valve was necessary t o secure constant pressure COIIditions throughout t h e r u n except a t t h e very last, when t h e quantity of distillate was very small. A t y p ical d a t a sheet is shown in Table I , which indicates t h e manner of making t h e distilla,tions. R u n N o . 43.
TABLE I-BIRCH February 7. 1914.
Temperature =C.
Time
FIG I-EXPERIMENTAL AUTOCLAVE
filled with a heating medium. T h e h e a t is supplied by means of a giant Bunsen burner. A mixture of sodium a n d potassium nitrates was found t o be a convenient b a t h material. il stirring device was provided for keeping t h e charge well mixed. . It was found necessary t o stir continuously during t h e exothermic reaction i n order t o secure check runs under a n y given conditions of pressure a n d size of chip. T h e temperature of t h e distillation was measured a t a point, as near t h e center of t h e charcoal residue as t h e stirrer would permit. I n order t h a t t h e reaction should be uniformly complete i n all cases, t h e distillation was considered finished when t h e constant maximum temperature was maintained for I O minutes with constant stirring. -4 final temperature of as near t o 3 3 5 O C. as possible was attained in each distillation. I n heating u p t h e retort with air alone i t was found t h a t t h e temperature in t h e retort mas constantly a b o u t 100' lower t h a n t h e b a t h temperature, probably due t o large conduction of h e a t through t h e heavy mall. Therefore, i n making distillations, t h e b a t h was raised t o a b o u t 4j0° C. a n d maintained a t t h a t temperat u r e throughout t h e experiment. O P E R A T I O N O F RETORT-Distillations were made using: ( I ) sawdust of t w o species, maple a n d birch; ( 2 ) chips averaging I b y l/g b y l / g inch of birch. For distillations in t h e autoclave t h e small material was selected because differences due t o different qualities of material could be obviated. T h e objections t o t h e
891
Autoclave
8 . 3 0 A.M. 9.39 9.51 9.57 10.02 10.06 10.09 10.11 10.13 10.15 10.16 10.17 I O . 18
.. .
116 155 179 194 209 225 242 250 272 286 298 311
.
Bath
CHIPS \Veight charge, 2903 g . Oven d r y weight. 2621 g.
Pressure Lbs.
Total distillate Cc.
,.
.... .... , ,..
363 400 415 425 429 435 440 442 442 443 444 447
60 60 60 60 60 60 60 60 60
..
60
I00 200 300) 400 500 600 700 , 800 900 1000
REMARKS
Gas on Distillation began 60 Ibs. reached
Tar started
I
Stirred continuously
Total, 1229
RESULTS RELATIOS
BETWEES
TIME, T E M P E R A T U R E , A K D P E R
DISTILLATE-Figs. 2 a n d 3 show t h e relation between time, temperature, a n d per cent of total distillate for typical distillations made a t 0 , 60, a n d 1 2 0 lbs. pressure. Distillations were usually complete within t w o hours after t h e distillate began c o n i n g over. It is evident from t h e temperature distillate curve t h a t t h e temperature was not t h e t r u e average temperat u r e of t h e autoclave b u t only served as a n indication of t h e r a t e of rise of t h e temperature. Free t a r began coming over in t h e distillate after a b o u t t h e same lapse of time in each c x e , b u t a t 1 6 0 " for o lbs., 180Ofor 60 Ibs. a n d a b o u t 210' C. for 1 2 0 lbs. pressure. F r o m numerous other experiments b y t h e a u t h o r a n d from t h e reports of other investigators t h e destructive distillation point accompanied b y t h e formation of free t a r occurs a t about 2 7 j c C. at ntmospheric pressure. T h e thermometer reading is, therefore, evidently too low during t h e distillation stage. However, since with air alone t h e thermometer could not be rasied within 100' of t h e b a t h , a n d since t h e final temperature was in nearly all cases about 100' lower CEXT OF
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 N G C H E M I S T R Y
89 2
t h a n t h e b a t h , t h e final indicated temperature was probably more nearly correct. N o allowance is made for t h e heat developed b y t h e exothermic reaction of distillation b u t with only about 3000 g. of wood this would not be very great. I n spite of t h e uncertainty of having measured t h e actual temperature t h e following effects of pressure or t h e manner of distillation are indicated: I-The decided difference in t h e temperaturetime a n d temperature-per cent distillate curves with
Vol. 6, KO.
11
t a r . The results obtained from different forms of wood a n d different species are given in Table 11. The results in each case are t h e average of at least three consistent distillations. T h e alcohol yields from chips are decidedly higher t h a n for sawdust of t h e same material. This was a b o u t t h e most i m p o r t a n t difference of chips over t h e smaller form a n d t h e cause is probably t h e size of t h e material. Distillations on 8o-lb. charges of wood 18” long a n d 3” X 3,’’ cross section from which
120
100
80
60
I f
:40
J
F 20
0 80
120
160
200
TCMCEIATUIIC-DCOICES
240
280
320
80
360
120
160
Frcs. 11 AND 111-RELATION BETWEEN TEMPERATURE-TIME A N D PERCENTAGE
increasing pressures is probably due entirely t o t h e increase in boiling point of water under pressure. At 60 lbs. pressure, water boils a t 1 5 j O C . ; a t 1 2 0 lbs. pressure, a t 176’ C. The flattening out of t h e curves for these pressures occurs very close t o these points. 11-Th6 destructive distillation point as indicated b y t h e formation of t a r takes place a t a higher temperat u r e with increasing pressure. 111-The higher t h e pressure t h e more distillate is obtained before t a r is formed during destructive distillation. The moisture content of t h e charge in TABLE 11-EFFECT
240
200
TEMPERATURE-DFGRECS
OF
360
these chips a n d sawdust were t a k e n gave 1.54per cent alcohol. T h e same thing held t r u e for maple. Sawd u s t gave lower yields of alcohol compared t o large forms of wood. T h e effects of pressure on t h e products of destructive distillation were independent of t h e form a n d species used a n d were in general as follows: A C E T I C ACID-Increased pressure tended t o decidedly decrease t h e yield of acetic acid, t h e average effect of distilling at 1 2 0 lbs. over o lb. being a decrease of a b o u t z j per cent. I n t h e case of maple sawdust
OF
0 60 120
320
TOTAL DISTILLATE
PRESSURE O N DESTRUCTIVE DISTILLATION (Results in percentages of oven d r y Concentration of Per cent. TAR dissolved pyrp acid Pressure t a r in minus MATERI-&L Lbs. Acid Alcohol Charcoal Dissolved Total distillate moisture Maple sawdust 8.04 9.05 35.0 0 5.59 38.93 3.74 1.09 60 4.81 1.18 41.49 1.33 3.23 3.49 28.8 2.72 27.66 0.97 2.67 4.10 1.08 42.46 150 8.53 36.37 11.98 0 6.76 37.2 5.28 1.15 Birch sawdust. , , . . , , . . , 29.95 4.25 2.93 5.34 40.38 1.40 60 1.23 29.84 3.86 2.71 42.07 1.12 5.20 1.25 120 Birch chips
280
CENTIGRADE
CENTIGRADE
6 32 5.61 5.44
1.42 1.50 1.53
36.61 39.5 40.48
12.55 6.29 5.64
t h e typical cases drawn would hot account for this difference as t h e o a n d 1 2 0 lb. runs were 18.9 per cent a n d 19.1 per cent moisture, respectively, while the 6 0 lb. r u n was 2 5 . 4 per cent moisture. E F F E C T O F P R E S S U R E O N PRODUCTS-The distillate from each r u n was allowed t o s t a n d until all free t a r h a d settled o u t a n d t h e clear pyroligneous acid h a d separated. Both acid liquor a n d settled tar‘ were t h e n weighed a n d measured. T h e crude pyroligneous acid was analyzed for acid, alcohol, a n d dissolved
16.96 11.70 9.08
24.4 12.1 8.75
42.64 34.23 32.90
weight of material)
19.70 25.10 25.55
Gas, t a r and charcoal 72.17 75.02 74.49 68.98 69.73 71.48
16.03 20.13 21.21
69.60 71 33 70.77
Gas 25.2 30.3 29.36
Tar and charcoal 46.97 44.72 45.13 49.18 44.63 45.93 53.57 51.20 49.56
a t I j o lbs. t h e yield of acid was 28 per cent less t h a n a t o lb. ALCOHOL-Up t o 1 2 0 lbs. t h e effect of pressure was t o increase slightly t h e yield of alcohol, about 8 per cent more alcohol being obtained a t this pressure over o lb. Three-quarters a s much increase, or 6 per cent, was obtained with 60 Ibs. pressure. I n t h e case of maple sawdust at 1 5 0 lbs. t h e yield was practically t h e same as a t o lb., indicating t h a t above 1 2 0 lbs. t h e effect
N o v . , 1914
T H E JOURLVAL OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
of pressure is t o decrease rather t h a n increase t h e yield of alcohol. This was also substantiated b y a number of preliminary distillations. . cHeRcoaL-LAt 60 lbs. pressure, 8 per cent more charcoal mas obtained t h a n a t o lb., a n d a t I Z O lbs. there was a n increase of 1 1 per cent over atmospheric distillations. DISTILLATE-The clear pyroligneous acid, independent of moisture content of wood! was decreased a b o u t 20 per cent under 60 Ibs. pressure b u t h a d only small further decrease a t I Z O lbs. or I j o lbs. cAs--There \\-as a similar b u t rei-erse effect on t h e gas (determined b y difference). At 6 0 lbs. pressure there was about 2 j per cent more gas t h a n :it o lb., b u t I Z O or 150 Ibs. only gave very little more gas or even less t h a n 6 0 lbs. (maple sawdust a t I j o lbs. gave z per cent less t h a n a t 6 0 lbs.). . TAR-The most decided effect of distilling under pressures greater t h a n o lb. was on t h e t a r . At 60 Ibs. t h e yield of t o t a l t a r ( t a r which settled o u t of t h e distillate plus t a r dissolved in t h e crude pyroligneous acid) was 60 t o 6 j per cent less t h a n a t o lb. a n d a t 1 2 0 lbs. a n d I j o lbs. pressure a b o u t 68 per cent less. This same effect was even more apparent on t h e dissolved t a r alone. A decrease of as much as 7 j per cent a t 1j0 lbs. over o lb. being obtained for maple sawdust. T h e high yield of t a r from birch chips a s compared t o sawdust was probably due t o t h e fact t h a t t h e chips were very d r y . Other work on a much larger scale has given t h e same effect using very d r y wood. R E L A T I O N B E T W E E N GAS, TAR, A N D C H A R C O A L
It seemed probable t h a t some relation might be established between gas, t a r , a n d charcoal, a n d this has been indicated in Table 11. A n y such relation is not very marked, however, although t h e s u m of t h e three products is fairly constant. It is of interest t o compare these results with some recent work of Klasonl who has studied t h e effects of distilling birch under pressures lower t h a n atmospheric, a pressure of 0.01 mm. being maintained even during t h e gas stage b y immersing t h e receiver in liquid air. I n brief, t h e same tendencies were obtained, v k . , t h e higher t h e pressure (in t h i s case atmospheric compared t o pressures of 0.01 m m . ) t h e more alcohol a n d charcoal were obtained a n d less t a r , b u t Klason reported practically no effect on t h e acetic acid. S U 31 M A R Y
I-Destructive distillations of birch a n d maple were made on a small scale t o s t u d y t h e effect of pressures greater t h a n atmospheric on t h e yields of products. 11-In general, t h e effect of destructively distilling wood under increasing pressure is t o increase t h e alcohol slightly when moderate pressures are used a n d t o increase t h e charcoal a n d gas. Further effects were t o decrease t h e acetic acid, t h e pyroligneous liquor, and tar. 111-The effects of 60 lbs. pressure over o lb. are much more decided on all products t h a n t h e effects of increasing t h e pressure beyond 6 0 lbs. 1 “Experiments on the Dry Distillation of Wood,” Peter Klason, Arch. f . Kemie M i n . and Geol., Vol. 5, KO.7.
893
IV-The most decided effect of pressure was on t h e t a r . At 60 lbs. pressure this product v,-as decreased 60 t o 6 j per cent. T--From a practical standpoint. t h e most interesting effect of pressure is in connection with t h e yield of soluble t a r . Distillations were made a t pressures as high a s I j O lbs.. b u t t h e exothermic reaction w2.s so violcnt t h a t it was not advisable t o continue t h e experiments. X t this pressure, t h e concentration of t k e clissolred t a r in t h e pyroligneous acid w a s so low t h h t redistillation was not necessary in order t o t i t r a t e t h e distillate -or in practical operation t h e f r s t distillation of the primary liquor would not be necessery in order t o make gray acetate of lime. It is possible t h a t pyroligneous acid free from soluble t a r might be obtained by subjecting t h e distillate to a high pressure during t h e x-apor stage b u t t h e application of this result is not yet ZIPparent. FORESTPRODCCTS LABORATORY XIADISOX,WISCOSSIN
OILS OF THE CONIFERAE: 111. THE LEAF AND TWIG AND THE CONE OILS OF WESTERN YELLOW PINE AND SUGAR PINE B y A.
W.SCHORGER
Received October 1, 19 14
T h e leaf oil of western yellow pine (Pipius $ o n derosa,. Laws.) has apparently never been examined chemically. Brown’ in 1901 briefly described a plant i n Ore-gon operating on t h e needles of Piiius p o n d e r o s a , t h e products obtained being oil a n d fiber. A t o n of t h e needles produced t e n pounds of oil, equivalent t o a , yield of 0 .j o per cent of ,oil, which is considerably larger t h a n t h e yield obtained from t h e California trees. L E A F A K D T W I G O I L S O F XVESTERN Y E L L O T V P I S E
T h e oils varied in color from bright yellow t o green. When exposed t o t h e light for t w o or three days t h e yellow oils also acquired a green color. Some oils showed a green fluorescence. FRACTIONAL DISTILLATION OF
THE
LEAFOIL O F
Boiling point, C. 16 1-1 65 165-170 170-185 385-250 155-185 (35 m m . )
~ ’ E S T E R N Y E L L O ~PVI K E
Per cent 10
64 9
12.5 3
PHYSICAL A N D CHEMICAL COXSTANTS OF THE OILS OF TVESTERXYELLOW PIXE S o s . 2 173-2443 distilled from needles only; 2497-2560, from needles and twigs Ester Percentage T7.0
Sampie Sp. gr. So. 15O C.
Ref. index 15“ C.
2173 2174 2384 2385 2386 2387 2403 2404 2442 2443 2497 2498 2499 2560
1.4815 1.4812 1.4794 1 ,4793 1.4789 1.4797 1.4807 1.4832 1 .4802 1 ,4808 1 ,4805 1.4837 1.4838 1.4812
0 8762 0.8718 0.8729 0.8750 0.8739 0 8747 0 8784
0,8849
0 8722
0.8765 0 8793 0,8838 0 8844 0.8755
a-PIsEsE-The 1
c
~
-15.73 -17.30 -18.72 -1i.62 -11.47 -18.62 -18 72 -16 81 -17.82 -19.59 -17.26 -17.02 -16.77 -15.94
after Acid Ester acetyl~No. ~ 90. ~ o ation 2.36 1.87 1.15 1.58 1.73 1.58 2.11 1.28 0.88 0.85 0.87 0.84 0.67 0.73
4.02 5.70 5.15 6.71 7.11 3.88 5.94 5.15 7.65 7.83 6.32 8.10 5.89 6.73
27.58 24.11 34.18 34.15 32.52 26.19 35.10 28.81 28.79 31.97 35.68 30.59 31 . 5 8 25.14
.
-h__
.4ce-
tate 1.41 2.00
1 .so
2.35 2.49 1.36 2.08 1.80
2.68 2.74 2.21 2.84 2.06 2.35
Free
alco-
Yield
hol
of oil
6 . 6 0 0.040 5 . 1 3 0 . 040 0 057 0 072 7 , 12 0 . 0 6 6 6.24 0.097 8.20 0.058 6 . 6 2 0 . I15 5 . 9 1 0.095 6.76 0,074 8.08 0.126 6.29 0.122 7.20 0.124 5.14 0.084
::;g
oil contains b u t a small a m o u n t
Scientific ilmerican, 84 (1901), 344.
