INDUSTRIAL A N D ENGINEERING CHEMISTRY
132
rubber lining attached inseparably to the steel by this process, is now available. It is of all flanged construction, with '/cinch rubber for corrosive service and '/rinch rubber for abrasion. This piping, which has been found adaptable in many process industries, promises to have an extended application. Rubber-lined relinable valves, which are highly satisfactory in handling corrosive and abrasive liquids, have been developed. The new process also permits of lining fans and pumps, centrifugal machines, mixers, eggs, lifts, thickeners, classifiers, rolls, vats, and bins. The Cutless rubber bearing, consisting of a resilient rubber lining vulcanized to a rigid sleeve, such as bronze, cast iron, steel, and hard rubber, is another development. The only lubricant for this bearing is water. Installations rang-
Vol. 19, No. 1
ing in diameter from l / 2 inch to 15 inches have been made. These bearings are particularly serviceable in sand and slime pumps in the mining and chemical field. Summary
The Vulcalock process for vulcanizing rubber to various materials affords a new chemical engineering material with all the physical properties of the material to which it is attached and in addition the useful abrasion-resisting properties of a soft vulcanized surface and the corrosion-resisting properties of either soft or hard rubber, without hazard of breaking or cracking in transportation, construction, or operation. The most likely source of difficulty or failure of this material lies in misapplication. The manufacturers should therefore be consulted in all cases of doubt on highly specialized problems.
Action of Sodium Hydroxide on Cellulose under High Pressure' By Sven O d h a n d S. Lindberg ORCANISKALABOUTORIETKGL. TEKNISKA H~CSKOLAU. STOCKHOLM, SWBDEN
ELLULOSE is known to be very resistant to weak alkaline solutions (1 to 2 per cent), a t temperatures below 120" C., and on this fact the well-known alkaline paper pulp process of Watt, Burgess, and others is founded. With increasing temperature and concentration certain changes occur, so that at a normality of about 3 to 4 and a temperature between 200' and 300" C., the cellulose passes completely into solution with the formation of a mixture of organic acids. At the same time methanol and acetone (mesitylene) are formed. When the methanol and acetone are distilled off and the solution containing the mixture of salts is concentrated and finally dry-distilled with water vapor, further quantities of acetone and methanol are obtained, together with oils and pitch. While the formation of acids under the conditions mentioned above has been studied by several investigators, the formation of methanol and acetone seems to have escaped observation. Historical
In 1871 and 1889 Hoppe-Seylerz treated cellulose (Swedish filter paper) with water and alkalies up t o temperatures of about 250' C. H e found that up t o 200' C. no appreciable reaction could be traced except that the cellulose had increased in volume and had become more translucent-i. e., the process known as mercerization had taken place. With concentrated alkalies (about 9 N) the cellulose went into solution a t 220-240" C. with the formation of about 360 cc. of gas per gram of cellulose. The gas was chiefly hydrogen (86.8 per cent hydrogen, 0.9 per cent methane by volume) and in the solution the following acids were obtained: formic acid, acetic acid, and other fatty acids (altogether 15.2 grams per 100 grams), oxalic acid 2437 grams per 100 grams, protocatechuic acid 1275 grams per 100 grams, together with protocatechol. Since the quantity of gas amounts to about 2.7 grams, i t is evident that 21.6 per cent of the cellulose was isolated as known substances. The amount of carbon dioxide formed was not determined. Tauss3 found that pure water dissolved up t o 9.4 per cent of the cellulose at 181" C., while 14 per cent sodium hydroxide a t 152' C. dissolved 77 per cent. No detailed investigation of the products was undertaken. In 1920 Fischer and Schrader4 made a more thorough investiReceived June 9, 1926. Bcr.. 4, 15 (1871); 2. physiol. Chem., 13. 66 (1889). a Dinglers polyfech. J . , 273, 286 (1889); 516, 411 (1890). 4 Ges. Abhandl. Krnninis Kohlc. 5 , 332 (1920). 1
f
gation. Filter paper was treated with 47 grams of 4.1 N potassium hydroxide and 27 grams of 5.0 N sodium hydroxide per 100 grams of cellulose a t temperatures from 200' t o 300" C. The insoluble residue varied between 2 and 36 per cent according t o temperature. Using NaOH a t 300" C. a quantity of carbon dioxide equivalent t o 9.3 grams per 100 grams cellulose was obtained and in the solution the following acids (about 20 grams per 100 grams cellulose) were identified: formic, acetic, protocatechuic, and lactic (?).
Material and M e t h o d
Two experiments were made, the first with filter-paper cellulose and the second with cotton. Both kinds of cellulose were tested for methoxyl, but none was found. EXPERIMENT 1-Filter paper (1157 grams) containing 1.4 grams of ash (0.12 per cent) and 48.6 grams (4.23 per cent) of moisture and 1107 grams of dry organic substance (95.5 per cent) was disintegrated with 1100 grams of fused sodium hydroxide and 7000 grams of water. The sodium hydroxide contained 90.64 per cent NaOH and 7.52 per cent Na2C03, the remainder being water. This is equivalent to 100 grams NaOH and 83 grams NazO, or 90 grams NaOH and 7.5 grams NazC03, per 1000 grams cellulose. The normality of the disintegrated mixture was about 3.56. A portion of this mixture weighing 600 grams (71 grams cellulose, 64 grams NaOH, and 5.3 grams NaZC03) was slowly heated in an autoclave to 102' C. until 400 cc. of air were drawn off, and then for 5 hours to 372" C., at which point the pressure was 241 atmospheres. After this temperature had been maintained for some time the autoclave was cooled down to 30" C. and the gas formed (7300 cc. a t 0" C. and 760 mm.) was drawn off and analyzed, with the following results: Per cent by volume Hydrogen Methane Other hydrocarbons Oxygen Nitrogen
93.5 1.9 1.9 1.9 0.8
The experiment was repeated six times with similar results and altogether 39,000 cc. of gas and 3885 grams of solution were obtained. The solution was yellow to brown in color, quite transparent, and had a strong odor of methanol and mesitylene.
INDUSTRIAL A N D ENGINEERING CHEMISTRY
January, 1927
To a portion of this solution (3665 grams) 100 cc. of water were added and the whole heated in a distilling vessel with glass-bead fractionating column and condenser. Between 35" and 100" C. a distillate was obtained containing chiefly methanol and acetone. From the distillate 5.95 grams of light oil were also separated. The methanol was determined according to the method of Kir~al-Biihn,~the acetone according to the method of Messinger.6 The quantities obtained were 3.84 grams methanol and 1.79 grams acetone. The water was then completely distilled off and from the distillate 9.72 grams of pitch were extracted with ether. The residue, consisting of various alkali salts of organic acids, was steam-distilled in an electrically heated retort a t temperatures from 110" to 585" C. No appreciable quantities of gas were obtained below 245" C. and most of the gas formed between 500" and 550" C. Altogether, 45,000 cc. gas (0" C., 760 mm.) were obtained from a quantity of salt equivalent t o 212 grams cellulose. The gas had the following composition: Per cent by volume Hydrogen Carbon dioxide Methane Nitrogen Carbon monoxide Hvdrocarbons Ojrygen
52.8 17.7 11.0 6.2 5.3 4.7 2.3
The retort contained a residue of 297 grams of sodium carbonate mixed with carbonaceous material. This was analyzed and the quantity of organic matter found to be 5.14 grams. Its composition is found in Table 11. The impure sodium carbonate contained 33.1 per cent carbon dioxide. The distillate from the dry distillation was a dark, oily fluid which was redistilled and purified in the same manner as described for the original solution except that the oil and pitch were removed by means oi ether. The distillation was made in a vacuum (3 mm.) and the fraction up to 105" C. was considered as light oil, between 105 " and 205" C. as heavy oil, and the residue as pitch. EXPERIMENT 2-This experiment was carried out with pure cotton and since it was to serve more as a control the investigation was not carried out in such great detail. Eighty-nine grams of dry cotton were mixed with 100 grams of fused sodium hydroxide and 620 grams of water and heated in the same way as described in the first experiment, to a temperature of 357" C. In the solution the quantity of methanol amounted to 0.81 gram per 100 grams dry cotton. The cotton before the treatment indicated no methoxyl. R e s u l t s and P r o d u c t s
I n Table I the products have been arranged according to the various stages and the quantities recalculated on the basis of 100 grams pure ash-free cellulose. The total carbon and hydrogen are also recorded. The figures in parenthesis indicate the analysis of the products as given in Table 11. The water formed is calculated from the hydrogen deficit. The balance shows certain losses in products (3.25 per cent) while there is a gain in oxygen owing to inevitable errors in operation and analysis. If, on the other hand, the water formed is calculated from the oxygen balance, we obtain instead 11.08 grams per 100 grams and the total loss in substance amounts to 6.57 grams, which is in better accord with loss in carbon, amounting to 6.18 grams per 100 grams. In Table I1 the composition of the products, the density, and the refractive index for the oils are collected. The oils were found to be highly unsaturated. 6 8
B n . , 47, 1084 (1914). I b i d . , 21, 3366 (1888).
183 Table I
-
' 4-
TOTAL
2 )
P&DU(ZPP:
WEIGHT Grams
ii
CARBON ~ Y D R O G E NOXYGEN Grams Grams Grams
Cellulose (starting rpaterial) 100.00 41.52 High-pressure heating
6.47
52.01
Methanol Acetone Oil (3) Extract, pitch (6) Gas (1)
0.12 0.05 0.17 0.01 0.90
0.47 0.12 0.13
0.94 0.35 0.44 0.27 1.40 1.16 0.08 0.07 1.56 0.39 D r y disfillafion Organic residue in soda ash (8) 2.42 2.08 0.23 Methanol 0.60 Acetone 2.14 3.45 5.11 6.42 Light oil, (4) Heavy oil (5) 3.28 3.92 Pitch (7) 3.00 3.73 Gas (2j 5.46 14.06 COz in soda ash 43.28 11.80 Total products 82.29 35.34 Water formed 14.40 Totals 96.69 35.34 6.18 Losses and errors (3.31)
0.08 0.07 0.36 0.64 0.39 0.31 1.77
...
4.87 1.60 6.47
...
...
...
0.26 0.20 0.30 0.95 0.67 0.25 0.42 6.83 31.48 42.14 12.80 54.94 2.93
Table I1 No.
REPRACTIVB COMPOSITION DENSITY INDEX H 0 C Percent Percent Percent n2:
MATERIAL Gas Gas Oil Light oil Heavy oil Extract Pitch Organic residue
1 2 3 4 5 6 7 8
25.15 38.90 79.22 78.42 83.64 90.00 80.49 85.85
58.00 12.60 11.72 10.06 10.02 10.00 8.39 3.48
16.85 48.50 8.06 11.52 0.34
...
...
O.S& 0.8792 0.9991
1:4?44 1.50 1.535
ii:iz
10.67
... .. .. ..
*.. *.. ...
Discussion
No single formula will account for the results obtained. Evidently, the first stage of decomposition is the splitting up of cellulose into glucose, which is known to yield lactic acid on treatment with alkali. According to Raper,' salts of this acid, when heated with alkalies and alkaline hydroxides, yield a mixture of the salts of formic acid, propionic acid, and butyric acid, from which the corresponding ketone~--(C~H~)~CO, ( C I H , ) ~ C O - ~mixtures ~~ and homologs may form, yielding some products which may have the characteristics of unsaturated oils. On the other hand, formic acid decomposes both into COa HZand HzO CO. These gases were found in the gas analysis previously mentioned, but according to Fischer and Tropsch8 this dissociation is a reversible one since carbon monoxide and hydrogen with alkali under high pressure yield formates, which may react in the following way: 2NaCOOH = NazCOa H.CHO (1)
+
+
NaOH
+ + NaCOOH + 2H.CHO = CH30H
(2)
A certain equilibrium between CHIOH, H.CH0, HZ, CO, and COZ is thus probable. In this connection it should be mentioned that Rinmang gave the following reactions when lactic acid is treated with alkali: 2CH3CHOH.COONa HgO CH4 2CH3CHOH.COONa 2Na2C01 Hz
+
+
+ 2NazC03 + C Z H ~ C H ~ C+ O HzO +
+ 2NaOH = (CH&
+ 2NaOH
=
CO
J . Physiol., 81, 216 (1905). Ber., S6, 2428 (1923). 9 Sjunde allm. Svenska kemistmotets forhandlingar (7th General Meeting of Swedish Chemists, Trans.), p. 30 (1921.) 7
8
Helium Found in Ontario-The field of production of helium gas has been widened to include the Canadian province of Ontario. The Ontario Government claims t h a t a deposit of helium gas has been discovered at Inglewood, about 40 miles from Toronto. Three wells have been taken over by the government and are being worked. Commercial development of helium gas on a large scale is expected to result. The discovery was made during the war b u t was kept a secret until recently when the wells were taken over by the government.
