BRITISH CHEMICAL ABSTRACTS
B — APPLIED CHEMISTRY
M AY 22 and 29, 1931*
I.-GENERAL; PLANT; MACHINERY.
Unfired pressure v esse ls. W . S p r a r a g e n (Ind.
Eng. Chem., 1931, 23, 220—226).—The design and materials for pressure vessels which are welded are dealt with. When properly applied fusion-welding may withstand pressures th a t would cause rupture of the material itself. Steel plate of not more than 0-2% C is recommended on account of the injury to higher-carbon steels by any method of heating or by hot- and cold- working. Longitudinal seams are welded best from both sides in a double V-groove, although a single V is satis
factory if improperly fused material is chipped out from the back and the place filled in. C. A. K i n g .
Kampf viscosim eter. E. La n d t (Z. Ver. deut.
Zucker-Ind., 1930, 80, 949—955; cf. Kampf and Schrenk, A., 1930, 1014; B., 1930, 844).—This instru
ment, in which the rotation of a solid body, suspended in the experimental liquid from almost frictionless bearings, is actuated by a falling weight and measured by the rate of fall of the weight, was found satisfactory with molasses and sugar syrups too viscous for capillary viscosimeters. I t requires about 200 c.c. of liquid.
At present no means are provided for maintaining con
stant temperature. The instrum ent can be used with liquids containing suspended particles, although these are not without influence on the results. W ith molasses the relation between actuating weight and rate of rota
tion was found to be strictly linear. J". H. La n e. Surface factor [of pow ders]. J. W. M e l l o r (Trans.
Ceram. Soc., 1930, 29, [Wedgwood Bicent. Comm. Vol., f t. I], 251—257).—Mathematical. R. J. C a r t l i d g e .
Making a three-com ponent liquid-vapour chart.
J. H a p p e l and J. G r i s w o l d (Chem. and Met. Eng., 1931, 38, 92—93).—A liquid-vapour diagram for the ternary mixture of benzene, toluene, and xylene, under atmospheric pressure, is given as an example.
D. K. M o o r e .
Flow of gases at high p ressu res through m etal pipes. D. M . N e w i t t and S . K. S i r k a r (Inst. Chem.
Eng., Mar., 1931, 17—26).—The frictional resistance to the flow of air, carbon dioxide, argon, nitrogen, hydrogen, and a 3 : 1 mixture of hydrogen and nitrogen through pipes of I in. and & in- diam. has been determined.
Reynolds’ index law has been verified and there is evidence of three distinct types of flow, viz., stream-line flow, .that with eddies due to initial disturbance but not sustained, and turbulent- flow in the latter size of pipe.
D. K. M o o b e .
Control of gas su p p ly at definite temperatures.
P. Tromp (Chem. Weekblad, 1931, 28, 163—164).—
n apparatus constituting an automatic valve, which is
closed by the melting of a fusible alloy when a pre
determined temperature is exceeded in a chosen locality,
is described. S. I . L e v y .
See A., April, 449, Radioactivity m ethod for ex a m ination of pow ders. A n alysis of m ixed volatile liqu ids. 455—6, D ensity determ inations with so lid s. 456, Colour m easurem en t. 457, A nalysis of g a s m ix tu res. E lectrodialysis apparatus. 538, Extraction apparatus for liquids.
Pa t e n t s.
Apparatus for drying filter-cake. 6 . W . J o h n s o n .
From P r o c t o r & S c h w a r t z , I n c . (B.P. 345,247, 18.12.29).—See U.S.P. 1,755,005 ; B., 1930, 887.
Preventing the form ation of film s and scu m s in water or w atery liquids and on surfaces in contact therew ith. A. E. W h i t e . From W a l l a c e & T i e r n a n P r o d u c t s , I n c . ( B . P . 345,637, 18.12.29).—S e e U . S . P .
1,745,141; B . , 1930, 968.
[Combined m anually and autom atically operated]
ch em ical fire extin gu ish ers. J. I I . C o l l i e and G. F.
R im m e k ( B . P . 345,744, 30.1.30).
Apparatus for op tically investigating the dust content of air and other g ases. H . W i t t e m e i e r
(B.P. 345,601, 23.7.30).
' Furnaces [internally corrugated].—See II. Fire- extin gu ish in g agen ts.—See III. Furnace lining.
Refractory brick.—See VIII. P a ssin g currents through g ases.—See XI.
II.— FU E L ; G AS; T A R ; MINERAL OILS.
Origin of coal. W. F u c h s and O. H o r n (Z. angew.
Chem., 1931, 44, 180—184).—A number of vegetable materials, such as cellulose, wood, cotton linters, grape sugar, cheese, and linoleum, carbonised in aqueous alkali under pressure by the method of Berl, Schmidt, and Koch (B., 1931, 50), yielded dark carbonaceous products which were non-coking ; these, after hydraulic pressing, all furnished briquettes from which firm, cakiDg cokes were obtainable. Briquettes so prepared from cellulose, lignin, and wood differed from coal in th a t they gave a brown streak, dark filtrates on treatm ent with alkali, and a strong reaction and orange colour with dilute nitric acid. A firm, though swollen, coke could thus be obtained from lignin, and no difference was observed between the coke from ordinary and deresinified pine woods. Coking is thus a property common to the carbonisation products of a diversity of materials and bears no special relation to natural coal-formation. Attention is drawn to the Tole of bacterial action, with reference to the work of Taylor
* The rem ainder of this set, of Abstracts will appear in n ex t week’s is su e / 465
B r i t i s h C h e m ic a l A b s t r a c t s — B .
466 Cl. I I . — Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s.
(B., 1927, 691 ; 1928, 509). Caking cokes could not be prepared from brown coal (cf. Berl, loe. tit.).
E. L e w k o w i t s c h .
C om position of coal : its rational an alysis.
W . F r a n c i s and R. V. W h e e l e r (J.C.S., 1931, 586—593.
Cf. B., 1929, 5).—Rational analysis of a coal involves the determination of the proportions of (a) the free hydrocarbons and resins, by extraction with pyridine ; (6) the ulmins, i.e., the compounds which are converted into alkali-soluble products by oxidation ; and (c) the resistant residue, previously termed the “ organised plant entities.” The “ reactivity index ” of the ulmins, i.e., the relative ease with which they are oxidised, is also determined. Oxidation is carried out by heating the coal with a solution of nitric acid, to which potassium chlorate may be added if necessary; the correct con
centration to use varies with the carbon content of the coal. Durains contain material, absent from clarains and vitrains, which is more resistant towards oxidation than the bulk of the ulmins and less resistant than are the plant entities, and causes some difficulty in the accu
rate separation of these two constituents. Eor such coals the analysis is modified by carrying out a series of oxidations with increasing concentrations of nitric acid, plotting the weight of residue against the concen
tration of acid, and extrapolating the straight branch of the curve back to the concentration appropriate to the corresponding clarain. Examples of rational analyses of British coals arc given. A. B. M a n n i n g .
A lum inium apparatus for determ ining the tendency of coal and other m aterials to self
ignition. D. J. W. K r e u l e x (Brennstoff-Chem., 1931, 12, 107—111. Cf. B., 1930, 847).—As a result of some preliminary experiments the following conditions have been chosen as standard : the coal sample (5 c.c.-) graded to 10—20-mesh (per cm.) as previously described, is introduced into the apparatus, which is heated to and maintained a t 120° until the temperature of the coal, up through which a current of carbon dioxide is being passed, reaches 116°. Oxygen (10 litres/hr.) is then substituted for the carbon dioxide and the heating of the apparatus is resumed a t a uniform rate of 1—3°/m in.;
if the temperature curve of the coal is abnormal a t a low rate of heating, i.e., if it passes through a maximum and again falls, a higher rate is used and the heating continued until ignition takes place. The temperature a t which the heating curve of the coal cuts th a t of the aluminium block (the “ Schnittpunkt ” ) is recorded.
Observations are also made of the temperature changes in the coal when the temperature of the aluminium block is maintained constant a t successively higher values ; the temperature curves so obtained pass through maxima and subsequently fall until a critical initial temperature is reached a t which the temperature of the coal rises rapidly until ignition occurs. The “ Schnitt
punkt ” is lower when a more finely-divided sample is u se d : with brown or bituminous coal it rises with an increase in the rate of heating, but with wood charcoal it is independent thereof. A. B. M a n n i n g .
M echanism of com bustion of individual particles of solid fu els. D. E. S m i t h and A. G u d m u n d s e n
(Ind. Eng. Chem., 1931, 23, 277—285).—Small carbon
spheres were heated in a vertical tubular electric furnace through which nitrogen was passed and the temperature of the spheres was measured optically. At a specified temperature the nitrogen was replaced by a uniform current of air, the sphere burned for a definite time, allowed to cool in nitrogen, and the loss in weight deter
mined. The results show th a t the “ specific surface reaction rate ” (i.e., rate of loss of carbon per unit area of surface) increases with rise in temperature of the surface and with increase of air velocity. The rate of reaction and its temperature coefficient are much greater for small particles of carbon than for large. Carbon spheres with a surface area of 10—70 sq. mm. give a higher surface temperature, and burn faster, in moist air than in dry. The explanation of the phenomena is
discussed. H. E. B l a y d e n .
Adsorptive properties of com m ercial lam p
black. M. M. D u b i n i n and S. A. T o r o b o v (J. Appl.
Chem., Russia, 1930, 3, 843—855).—Ignition or activa
tion with steam or nitric acid partly, or with potash and hydrochloric acid thoroughly, cleans the surface. Methyl
ene-blue and iodine are readily adsorbed from aqueous solution ; the adsorption of acids is slight and complex.
Ch e m i c a l Ab s t r a c t s.
Apparatus for sam p lin g powdered fuel. D . J. W.
K r e u i j e n (Chem. Weekblad, 1931, 28, 66).—A small scoop, by the aid of which rapid and uniform sampling may be effected, even when the moisture content varies from place to place in the material, is described.
S. I . L e v y .
Effect of sodium carbonate on gasification of carbon and production of producer g a s. D . A.
Eox and A. H. W h i t e (Ind. Eng. Chem., 1931, 23, 259—266).—The reaction products of sodium carbonate and carbon a t 1000° are shown, by experiment, to be carbon monoxide and sodium. In the gasification of carbon by carbon dioxide, the sodium vaporises and reacts with carbon dioxide to form sodium oxide and carbon monoxide, the sodium oxide further re a c ts
with carbon monoxide to form sodium carbonate, and the sodium carbonate is drawn back to the surface of the carbon and again enters the reaction; the net effect is similar to th a t which would obtain if the vapour pressure of the carbon were increased to 1015 times its actual value. The gasification of carbon by water vapour in the presence of sodium carbonate can be similarly explained. The use of coke impregnated with sodium carbonate in the gas producer will cause a more rapid approach to equilibrium and also a change in the gas composition, due to the presence of sodium vapour, the gas having higher concentrations of carbon m o n o x id e
and hydrogen than those usually found ; the use of basic refractories in the lining is suggested. The use, however, of sodium carbonate f o r water-gas m a n u f a c t u r e
is not recommended, as although high steam decomposi
tions and small amounts of carbon monoxide would be obtained in the “ run ” period, large amounts of carbon monoxide would also be produced during the “ blow
period. C. B. M a r s o n .
Naphthalene rem oval [from g a s] b y m eans of tetralin. P. D e u t s c h (Gas- u. Wasserfach, 1931, 74, 245—247).—A consideration of the vapour p r e s s u r e
B ritish C h e m ic a l A b s t r a c t s — B .
Cl. I I . — Fu e l ; Ga s ; Ta b ; Mi n e r a l Oi l s. 407
of tetralin and its solvent power for naphthalene shows it to be highly suitable for spraying into town’s gas to prevent deposition of naphthalene, being as effective as 14 times the amount of xylene. Experiences with the use of tetralin are described, the average amount used being 0-03 lb., costing 0 - Id. per 1000 cub. ft. of gas.
The adoption of the process should effect considerable
economy. .A. K e y .
Testing of g as m a in s w ith ethyl m ercaptan.
A. T h a u (Gas- u. Wasserfach, 1931, 74, 247—250).—
It is concluded th a t ethyl mercaptan, because of its penetrating odour, volatility, harmlessness, and insolu
bility in water, is a very suitable substance to add to coal gas or natural gas for the detection of leaks in the mains. An account is given of experiences a t Franklin and Middletown, U.S.A. For the testing of consumers’
installations, about 4 g. per 1000 cub. ft. are introduced into the gas, using an apparatus which is described, followed by a larger amount, 16—20 g. per 1000 cub. ft., for the testing of underground mains. A. K e y .
M aterials for purifying acetylene. I, II . K.
S u m iy a and S . Y a m a d a (J. Soc. Chem. Ind., Japan, 1930, 33, 527—529 b , 530 b ) .—I. The efficiencies of various commercial preparations for the purification of acetylene (containing hydrogen phosphide, but not sulphide) were measured by a comparative method, using a mixture of an acid clay with 10% of hydrochloric acid containing 5% of mercuric chloride as standard.
Of the non-recoverable purifiers, “ Heratol ” (cf. G.P.
116,058) is recommended ; purifiers of this class, based on bleaching powder, absorb impurities well, but contaminate the gas with chlorine. Of the recoverable materials, Booer’s preparation (B.P. 181,571 ; B., 1922, 579 a ) is the most efficient, and its regeneration by air appears to be complete.
II. The addition of a minute amount of mercuric chloride to recoverable purifying materials (consisting chiefly of infusorial earth and ferric chloride) enhances the purifying action ; a small amount of cupric chloride, sulphate, or acetate, or copper powder accelerated regeneration, which was also assisted by the addition of ferric acetate. The following proportions are recom
mended : ferric chloride 9 pts., copper acetate 0-6 pt., mercuric chloride 0-15 pt., ferric acetate 1-68 pts., infusorial earth as required. E. L e w k o w i t s c h .
Hydrogenation of b itum en from the bitum inous sands of Alberta. E. H. B o o m e r and A. W. Sa d d i n g t o n
(Canad. J. Res., 1930, 2, 376—383).—The sands were intimately mixed with sodium silicate, heated, and added to a large volume of hot salt water. The crude bitumen separated thereby had d15 0-9984 and con
tained sulphur 4-16%, water 1-0% , and carbon residue 14-3%. Hydrogenation of the bitumen a t high tem
peratures and pressures, -with and without catalysts, resulted in the formation under the most favourable conditions of 80% of a light crude oil. The optimum temperature was about 380°. The best catalysts used were ammonium molybdate and aluminium chloride, the latter producing little gas and coke, b u t having the disadvantage of being corrosive and yielding an oil containing hydrogen chloride. The other catalysts had little effect on the time of reaction, bu t caused a marked
decrease in the formation of coke and ga.-;. An absorp
tion of hydrogen equal to about 3 wt.-% of the bitumen was obtained. The resultant oil had a sulphur content about one half th a t of the bitumen and was easily refined to produce a stable white gasoline.
H. S. Gajiuck. Soluble tars from m aritim e pine w ood. G . Du
P o n t and J. L . L u s s a u d (Bull. Inst. Pin, 1929, 301— 311. Cf. Hawley and Calderwood, B., 1925, 198).—
The dissolved tarry m atter in crude pyroligneous liquors from maritime pine gives on evaporation in a vacuum a t 100°/20 mm. a viscous, brown residue almost com
pletely soluble in water. This complex mixture yields no useful results by extraction with organic solvents or by neutralisation and extraction. Distillation up to 100° a t 1—3 mm. resinifies about 50%. In the distillate there are present furfuraldehyde, methylfurfuraldehyde, acetic and propionic acids, butyrolactone, 3 : i-dihydro- pyrocatechol, m.p. 104°, maltol [3-hydroxy-2-methyl- 1 : 4-pyrone], m.p. 156—-157°, and a t least two phenolic substances not obtained sufficiently pure for identifica
tion. C. H o l l i n s . .
D esulphurisation and catalytic hydrogenation of a fraction of prim ary tar. J. M. P e r t i e r r a (Anal.
Fis. Quim., 1930, 28, 1435— 1450).—The sulphur con
tent (0-70%) of a 180—300° fraction of primary tar was present chiefly as hydrogen sulphide 0-17% , mer- captans 0-09%, thioethers 0-04% , and thiophens 0-14%. On passage of the vapour of the fraction ad
mixed with hydrogen over certain metallic oxides pre
viously reduced by hydrogen and heated a t 300—350°, a maximum of 60% of the sulphur was removed ; after a second treatm ent the content of basic substances fell by 64 *2% and of phenols by 13-3%. The product of berginisation of the primary tar, after removal of the lighter fractions, and using ferric or molybdenum oxide as catalyst, contained phenols 7-2% , bases 13%, neutral oil 86-6%, and was completely soluble in ether, showing complete removal of the ulmin content (2-6%) of the tar. The initial b.p. was 50°, and 13-9% ¿stilled below 185°; the distillate (50—180°) contained aro
matic hydrocarbons (29-1%) and unsaturated hydro
carbons (42-3%). H. F. G i l l b e .
T herm al decom position of coal-tar constituents.
VII. Reaction products of the therm al decom posi
tion of m -cresol. VIII. Reaction products of the therm al decom position of o- and p -c r e so ls. IX.
Reaction m ech anism of the therm al decom posi
tion of cresols. Y. K o s a k a (J. Soc. Chem. Ind., Japan, 1931, 34, 10—12 B , 12—13 B, 13—14 B ; cf. A., 1930, 332).—VII. Pyrolysis of m-cresol a t 700° and 800° in contact with silica and coke, and a t 900° with
out contact material, gave (approx.) 95, 69-5, and 38%
of condensate, respectively. The corresponding volumes of gases evolved, based on 1 g.-mol. of m-cresol, are : 3-5, 30, and 51 litres. Deposits of carbon were found a t the three temperatures, viz., 0-5% , 3-25%, and 15%.
A table shows the amounts of compounds identified among the condensates. The amount of cresol unde
composed a t 900° is about 0-7% , a t 800° 21%, and a t 700° 86%. The contact material exerts little influence on the products. As the temperature of decomposition
a 2
B r i t i s h C h e m ic a l A b s t r a c t s — B .
468 Cl. I I . — Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s.
rises, the yields of benzene, toluene, and phenol appear to reach a maximum, those of naphthalene and anthrac
ene vary little, whilst the production of diphenyl etc.
increases.
VIII. o- and p-Cresols gave decomposition products (800°, with silica) similar to those obtained with the
«¿-compound. Tables give a comparison of the amounts of products condensed from the three isomerides (decomp.) a t 800° as well as the composition of the gases produced. The chief differences are in the quan
tities of undecomposed cresols (o -12%, m- 8%, p- 24%) and the yields of phenol (o- and p- each 19%, m- 4 • 6%).
IX. A scheme of 8 reactions is given to account for the formation of the substances identified among the products of decomposition. The differences observed in the behaviour of the three isomerides are accounted for by the fact th a t the methyl group in m-cresol is more stable than the hydroxyl group. In the o- and p- isomerides these relations are reversed.
H . In g l e s o n.
Fluorescence analysis of coal-tar and petroleum pitch. W. T e u s c h e r (Chem.-Ztg., 1930, 54, 987).—
Coalrter pitch is detectable in petroleum pitch (asphalt), but not vice versa, by its more characteristic fluorescence in 1/50,000 dilution under quartz-lamp illumination (cf.
Haitinger and Reich, A., 1929, 1127).
L . J. H o o l e y .
M echanism of form ation of higher hydrocarbons from w atęr-gas. D. F. S m i t h , C. O. H a w k , and P. L.
G o l d e n (J. Amer. Chem. Soc., 1930, 52, 3221—3232).
—When ethylene and mixtures of ethylene and carbon monoxide or hydrogen are passed over a cobalt-copper- manganese dioxide catalyst (B., 1929, 82) a t 206°, no reaction occurs. Passage of heavy hydrocarbons does not result in cracking; this process or polymerisation of ethylene does not occur in the reaction previously studied (loc. cit.). Acetone is not an intermediate pro
duct, since only 4—7% is converted into a water- insoluble oil by passage over the catalyst. When mix
tures of ethylene, carbon monoxide, and hydrogen (containing more than 10% of the hydrocarbon) are used, higher hydrocarbons and oxygen-containing compounds, b.p. below 100°, are produced. The oxy
genated compounds are dehydrated and partly poly- metised under the conditions used, and their formation depends on th e concentration of the water-gas and not the ethylene (above 10%). When water-gas is passed over an iron-copper catalyst a t 256—266°, only small amounts of methane and higher hydrocarbons are pro
duced ; carbon dioxide is the predominating reaction product. With a mixture of ethylene and water-gas no oxygen-containing compounds are produced and the ethylene does not react a t all. The action of an iron- copper-manganese dioxide catalyst is similar to th a t of the iron-copper catalyst. H . B u r t o n .
H ydrogenation of petroleum o ils. R. H. M c K e e
and A. S z a y n a (J. Inst. Petroleum Tech., 1931, 17, 121—132).—A review of certain published information dealing with this subject on the lines originally adopted
byBergius. H. S . G a r l i c k .
A ction of inorganic refining reagents on alkyl sulphides in naphtha. P. B o r g s t r o m a n d J. C.
M c I n t y r e (Ind. Eng. Chem., 1931, 2 3 , 321—323).—
The effect of the various reagents on naphthas containing the following alkyl sulphides, viz., ethyl, «-propyl, isopropyl, aliyl, »¡-butyl, zsobutyl, sec.-butyl, «-amyl, isoamyl, sec.-amyl, see.-hexyl, «-heptyl, sec.-octyl, and benzyl, has been studied. Alkyl sulphides having two or three carbon atoms in the chain are almost completely removed, whilst those with five or more are but slightly removed, when using mercuric acetate or chloride solution. When a solid such as silica gel, th a t has adsorptive powers, is used, the extent of the removal is dependent on the length of the carbon chain. Solid mercurous nitrate removes the lower sulphides, but is not so effective with the higher secondary sulphides.
C. B. M a r s o n .
What determ ines the value of absorption oil ? F. L . K a l l a m (Chem. and M e t . Eng., 1931,38,78—81).—
A series of curves showing the physical characteristics of new and used absorption oils employed in the petrol
eum industry are given. D. K . M o o r e .
R egenerating litharge for sod iu m plumbite
“ d o c to r ” [solution for petroleum refining].
(Chem. and Met. Eng., 1931, 38, 76—77).—The spent liquor containing 0-6% PbO as sodium plumbite, 4%
PbS as sludge, and 11% caustic soda solution separates on keeping into a top layer of oil, a middle layer of emulsion of caustic soda and naphtha containing the solid lead sulphide, and a layer of alkaline plumbite at the bottom. The emulsion is cut by heating to 66°
with the addition of a little sulphur, and the lead sulphide which settles out is mixed with the previously separated alkaline plumbite, heated to 80°, and oxidised by blowing air through the suspension to plumbite with the formation of sodium thiosulphate. The colour is removed from the regenerated liquor by washing with the previously separated oil. The concentration of the sodium thiosulphate is kept below 25% by withdrawing from circulation some of the spent liquor.
D. K. M o o r e .
Lum inous station ary flam es : quantitative rela
tionship between fla m e d im ensions at the sooting point and chem ical com position, w ith special reference to petroleum hydrocarbons. S. T. M tn -
c h i n (J. Inst. Petroleum Tech., 1931, 17, 102—120).—
The method of Kewley and Jackson (B., 1927, 642) for evaluating the burning of kerosenes has been extended in order to ascertain quantitatively the dependence of the tendency to soot on the composition of the oil.
Standard distillation cuts, essentially completely par- affinic, naphthenic, and aromatic, respectively, were prepared by methods described, and the maximum flame height, tendency to smoke, and aniline points were determined on various blends of these and on fractions cut from the various treated and untreated crudes taken every 10° from 150° to 280° through a Hempel column. The results show th a t the tendency to smoke of a kerosene is directly proportional to its aromatic and naphthene content and, in general, to the boiling range.
For the boiling ranges considered, the relative smoking tendencies of paraffins, naphthenes, and aromatics, respectively, are 4-4, 13-1, and 42-4. Various sub
stances were burned in the Weber photometer and their
B ritis h C h e m ic a l A b s t r a c t s — B .
Cl. I I .— Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s. 409
smoking points and the heights and radii of the flames produced were measured. From the results an equation is derived whereby the tendency to smoke can be calcu
lated for any homologous series. The paraffins show an increased smoking tendency with increase in mol. wt., but in all other homologous series the tendency is for a decrease. For a petroleum mixture the sooting tendency increases with increase in b.p. H. S. . G a r l i c k .
Ultra-violet spectroscopy of flam es of m otor fuels. V. A n a ly sis of gasoline for iron carbonyl by m eans of a sm a ll q uartz-prism spectrograph.
6. L. C l a r k , V. It. H a r d y , and H. B. W i l l m a n (J.
Physical Chem., 1930,34,1924— 1929 ; cf. B., 1929,504).
—A method using the ultra-violet spectra of gasoline flames as an accurate and sensitive means of determining iron carbonyl in gasoline is described. A small quartz- prism spectrograph will detect the carbonyl down to a concentration of 6-2 X 10~7 g. of iron per c.c., whilst a larger spectrograph will detect a concentration of the order of 5-4- X 10~7 g./c.c. The line 2450-4 A. now recorded has not been identified previously in either the flame or the electric-furnace spectrum, whilst the lines 3760-0, 3651-0, 3634-4, 3611-0, 3005-6, 2776-0, 2731-0, 2710-0, 2509-9, 2502-2, 2479-8, 2462-8, 2453-50 A.
have been identified in a flame for the first time.
L. S. T h e o b a l d .
Modified ab sorption-distillation m ethod for analysis of cracked g asolin es. C. C. T o w n e (J. Inst.
Petroleum Tech., 1931, 1 7 , 134—141).—Using synthetic mixtures of hydrocarbons, three methods for the analysis of cracked gasoline have been developed : (a) a gravi
metric (barium salt) method in which absorption in 98% sulphuric acid is followed by decomposition of the unsaturated derivatives with barium hydroxide and determination of the barium in solution correspond
ing to the aromatics. Means for arriving a t an average mol. wt. by similar means are described. (b) Using the above method as foundation, a rapid approximate absorption procedure was developed. Unsaturated compounds are absorbed by treatm ent with cold 93%
sulphuric acid in a 1-min. application. The aromatics are determined by absorption of the residual hydro
carbons in 98% sulphuric acid in 30 min. (c) For quick practical work a final procedure is to determine part of the unsaturated constituents by absorption in 3 vols.
of cold 93% sulphuric acid for 1 min., and the remainder by distillation to a predetermined temperature after treatment with 98% acid. The effect of the solvent action of sulphuric acid of different concentrations on a number of pure hydrocarbons is tabulated.
H. S. G a r l i c k .
Lubricating properties of m in eral, vegetable, and fatty o ils. A. S. T . T h o m s o n and P. S. C a l d w e l l
(J. Roy. Tech. Coll., Glasgow, 1931, 2, 490—502).—
Comparisons have been made by means of the Deeley and Boult standard testing machines, and a variable- gear-driven friction machine having a cylindrical, double- ring, oiler-type journal bearing, with an oil-bath. Static and fluid friction and viscosity (yj) tests were made on turbine, double-Shell, sperm, rape, castor, and pure Bayonne mineral oils, and on blends of the above oils with one another and with oleic acid. The static friction
(¡j.) is low for fa tty oils (i.e., the “ oiliness ” factor, 100—100 \l, is high), whilst blended oils have values intermediate between those of mineral and fa tty oils.
Since solid-friction conditions almost certainly exist when a machine is started up, it is advisable to add a fatty oil to increase the oiliness of a mineral oil and so reduce the friction. W ith animal and vegetable oils the decrease of vj with rise in temperature (up to 200° F.) is less rapid than with mineral oils, so th a t a t high temperatures the lubricating film can withstand pressure tending to break it and so produce solid-friction condi
tions. Under viscous-friction conditions the lubricating film forms more readily when vj is high, but has a lesser tendency to form and a greater tendency to break down at low rubbing speeds (and vice versa), ¡x being directly proportional to this speed. Under fluid conditions (X decreases with the load up to a certain value of the latter.
Small bearings, which involve relatively high loads, produce less friction than large bearings (low loads), but their films are more liable to breakage by over
loading. J. G r a n t .
A m ount of lubricating oil burned in the gasoline engine. C. C. M i n t e r and W. J. F i n n (Ind. Eng.
Chem., 1 9 3 1 , 2 3 , 2 8 5 ) .—Commercial electrolytic hydrogen was led into the intake pipe of a single-cylinder engine which had previously been freed from carbon deposits.
The engine was lightly loaded and run a t 6 0 0 r.p.m.
The cooling water was kept a t 1 0 0 ° . The exhaust gases were sampled and analysed, the amount of carbon dioxide present giving an indication of the amount of oil burned. A negligible quantity of oil was burned when the hydrogen was in excess. An oil of low viscosity showed less burning than one of high viscosity.
C. B . M a r s o n .
Effect of carbon black on insulating o ils. W. B . W i e g a n d , C. R. B o g g s , and D. W. K i t c h i n (Ind. Eng.
Chem., 1 9 3 1 , 2 3 , 2 7 3 — 2 7 6 ) .—Carbon black has been used successfully to improve the electrical properties of insulating oils. New transformer oils, when treated either by filtration or by sedimentation with dried carbon black, gave an average improvement in dielectric strength of about 40%. Active carbon black tends to remove moisture, electrolytes, and suspended particles.
C. B . M a r s o n .
P yrogenic decom position of paraffin oil in the presence of various catalysts and under high hydrogen p ressu re. R. O d a (J. Soc. Chem. Ind., Japan, 1 9 3 1 , 34,58—6 2 b ) .—A paraffin oil (no distillate below 3 0 0 ° / 7 6 0 mm. ; 6 0 % between 8 3 ° and 2 1 5 ° / 4 mm.) from a North Japanese crude was heated under pressure up to 4 5 0 ° (within 1 hr.) in the presence of metallic oxides, silica, iron, or bleaching earths, the rate of change of pressure being observed for comparison. In the presence of catalysts, after a short halt a t 4 5 0 ° , the temperature rose spontaneously by some 3 0 ° as a result of exothermic polymerisation of the unsaturated pro
ducts : in general, catalysts decreased the amount of cracked oil formed and increased the yield of gas and coke ; further, cracked oils obtained with a catalyst gave more of the lightest fractions and less pitch on distillation. Similar experiments conducted in a hydro
gen atmosphere are detailed. E. L e w k o w i t s c h .
B r i t i s h C h e m i c a l A b s t r a c t s — B .
470 Cl. I I . — Fu e l ; Ga s ; Ta b ; Mi n e r a l Oi l s.
Critical solution tem peratures of sy stem s of sulphur dioxide and norm al paraffins. W. F.
S e y e r and E. Todd (Ind. Eng. Chem., 1931, 2 3 , 325—
327).—Investigations into the systems sulphur dioxide with seven hydrocarbons of the C„H2,i + 2 series (n = 4. 6, 8, 10, 12, 14, 32) showed th a t the critical solution tem perature was a function of the mol. wt.
of the hydrocarbon. The am ount of hydrocarbon soluble in sulphur dioxide a t its b.p., — 10°, is compara
tively small. C. B. M a k s o n .
Liquid-vapour chart.—See I. A m m onia sy n th esis. Sulphur in o ils.—See VII. Baku lubricat
ing o il.—See X II. Synthetic resin s from lignin .—
See X III. B row n coal and grow th of crops.—See XVI.
See also A., April, 419, Adsorption of ethylene.
436, Flam e speeds of carbon m on oxid e-oxygen m ixtu res. 441, E thylene and acetylene from m ethane. 450, A n alysis of m ixtu res of hydrogen, m ethane, and ethane. 460, Form ation of petroleum
deposits. H istory of coal.
Pa t e n t s.
Carbonisation process and apparatus therefor.
F. C . G r e e n e and I. F. L a u c k s , Assrs. to O l d B e n C o a l C o r p . (U.S.P. 1,771,999, 5.8.30. Appl., 18.9.24).
—In a vertical retort fitted with a screw conveyor the coke is prevented from sticking to the conveyor by introducing into the carbonisation chamber, through a channel inside and openings in the conveyor, a suit
able lubricant, e.g., oil or powdered graphite, conveyed by a stream of gas or by gas under pressure.
D. K . Mo o r e.
Coke oven and other furnace [with corrugated heating surfaces]. C. 11. B e l l a m y , Assr. to W. H.
B l a u v e l t (U.S.P. 1,772,413, 5.8.30. Appl., 17.11.26).—
The walls of the oven are horizontally corrugated on each side to offer increased surface for heat transmission.
D. K . Mo o r e.
D istillation of carbonaceous m aterials. W . C .
K i r k p a t r i c k , Assr. to W e s t e r n G a s C o n s t r u c t i o n Co.
(U.S.P. 1,770,984, 22.7.30. Appl.. 4.8.21. Renewed 15.12.23).—A continuous vertical retort consists of a central cylindrical portion forming the combustion chambers, surrounded by an annular space forming the retort, and this also is surrounded by an annular space forming distillate chambers. The retort is divided into a number of compartments separated by winged con
veyors which, on rotation, feed the- material being carbonised from one compartment to the next below and at the same time form a seal. Each compartment communicates with its own separate distillate chamber and condenser. The distillate from each compartment is thus separately removed and cracking is eliminated.
D . K. M o o r e .
Manufacture of fuel briquettes. C . V. M c I n t i r e ,
Assr. to C o n s o l i d a t i o n C o a l P r o d u c t s C o . ( U - S .P .
1,772,053, 5.8.30. Appl., 29.5.26).—Satisfactory bri
quettes containing 8—13% of volatile m atter (excluding water) are made by mixing semi-coke w ith 10—12% of pitch, so th a t the raw briquette contains 18—20% of volatile m atter, and then carbonising by radiant heat a t 650—750° for 30 min. D. K. M o o r e .
Production of carbonised briquettes. C. V.
M c I n t i r e , Assr. to C o n s o l i d a t i o n C o a l P r o d u c t s Co.
( U . S . P . 1,772,189, 5.8.30. Appl., 15.7.24).—Briquettes made from low-temperature coke and pitch or asphalt are heated in a continuous vertical retort to about 700° by adm itting near the bottom a mixture of air and combustible gas and higher up more air, bu t in no case is the supply of air sufficient for complete combustion of the combustible gases. The exit gas preheats the air, and then part of it, enriched by other combustible gas, is used for heating the retort. D. K. M o o r e .
M anufacture of absorbent m aterials [from peat].
W.W. O d e l l (U.S.P. 1,768,963,1.7.30. Appl., 24.9.24).—
The peat is macerated, dried, and carbonised, all opera
tions being carried out in an atmosphere free from oxy
gen. The addition of certain substances, e.g., ammonium salts or alkali resinates, reduces the tendency of the peat to crack during drying. By varying the conditions under which the operations are carried out the porosity and density of the resulting product may be varied. The absorbent material may be rendered catalytic by mixing in catalysts, e.g., platinum salts, during maceration.
D. K. M o o r e .
A pparatus for producing carbon black. C. F.
C r o m m e t t , Assr. to L. N. W h e e l o c k and W. J. H a w k i n s
(U.S.P. 1,772,984, 12.8.30. Appl., 15.11.23).—Hydro
carbon gases are decomposed in the absence of air in a tube of nickel or other catalytic material. The tube is mounted in a furnace setting and carries a centrally disposed, rotatable tube which delivers the gas by means of jets on to the inner surface of the tube and also carries scrapers which remove the carbon as soon as it is deposited. The carbon then falls to a cooling chamber.
T. A. S m i t h .
Apparatus for producing carbon black. W.
H u n t ( U . S . P . 1,773,002, 12.8.30. Appl., 19.1.28).—
Gas for the production of carbon black is passed through a central tube of a burner, through the outer annulus of which a combustible gaseous mixture is passing. A number of such burners deliver into a firebrick furnace and the products of combustion are passed downwards through a cooling chamber where they are cooled with a spray of water. Carbon black is collected on a water- seal a t the bottom of the cooling chamber.
T. A. S m i t h .
Gas producers. H. F. S m i t h , Assr. to G a s R e s e a r c h
Co. ( U . S . P . 1,772,642—3, 12.8.30. Appl., [ a ] 17.11.21,
[b ] 27.4.22).—( a ) A gas producer for supplying small gas engines consists of a shell with a centrally disposed offtake for the gas. Combustion is arranged to take place between the grate and offtake, the fuel in the shell acting as insulating material. The absence of masses of insulating brickwork which requires to be heated up makes it possible to bring the producer into action more quickly. A saturator is arranged so th a t the hot gases vaporise the water by heat-exchange, (b) A large gas producer is fitted with a rotating top carrying two steam- operated pokers and fuel hopper. A master-valve controls the supply of steam to the pokers and turning engine. The exhaust steam from the pokers, engine, etc. is used in the saturator. Cooling is provided for parts of the rotating-head, poking, and fuel-feed
mechanism. T. A. S m i t h .
B r itis h C h e m ic a l A b s t r a c t s — B .
C l. I I .— Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s. 471
Producer-gas apparatus. E. S c h u m a c h e i i , Assr. to
F r a n k f u r t e r G a s g e s . (U.S.P. 1,772,819,12.8.30. Appl,, 24.1.25. Ger., 1.2.24).—Apparatus for the low-tempera- ture carbonisation and drying of fuel is fitted to the top of a producer-gas generator. Two concentric tubes are mounted above a stationary plate, the outer tube being rotatable and fitted with a scraper which delivers fuel to the generator. The fuel is fed into- the space between the tubes and is dried and distilled by the hot gases which pass from an annular outer space, through the fuel, to the inner tube, which carries off the gas from
the generator. T. A. S m i t h .
Apparatus for m anufacturing w ater-gas. W. E.
S t e i n w e d e l l , Assr. to G a s M a c h i n e r y Co. (U.S.P.
1,772,789, 12.8.30. Appl., 15.2.28).—Gas from a gener
ator is delivered downwardly to a carburettor, the duct having a centrally disposed oil spray. An air duct also leads to the top of the carburettor. During the “ blow ” period air is adm itted to the top of the carburettor and prevents the end of the spray from being burned off.
During the carburetting period the spray is kept cool by means of the oil. B etter carburetting with lower maintenance costs is obtained. T. A. S m i t h .
Gas-treating apparatus [for internal-com bustion engines]. G. E. C o o k (U.S.P. 1,772,746,12.8.30. Appl., 1.2.28).—Exhaust gases are passed first through a layer of activated charcoal or other drying material and then through a bed of “ hopcalite ” to absorb carbon mon
oxide. T. A. S m i t h .
Synthesis of m ethane from g ases. A. H . W h i t e
(U.S.P. 1,772,652, 12.8.30. Appl., 5.10.25).—Mixtures of carbon monoxide and hydrogen are passed over a nickel catalyst supported on magnesium oxide or calcium oxide. The reaction 2CO -j- 2H2 = CH4 + C02 takes place over the range 230—-760°, the carbon dioxide produced combining with the oxide. The temperature is then raised so th a t the carbonate produced is decom
posed, and afterwards lowered to the .temperature at which it is capable of producing the synthesis of methane.
T. A. S m i t h .
Manufacture of asphalt b y oxidisin g heavy petroleum hydrocarbons. A. F. M a c L a c h l a n (U.S.P.
1,774,756, 2.9.30. Appl., 12.5.28).—Petroleums or petrol
eum residuums (above d 0-909) or such hydrocarbons mixed with natural or prepared asphalt are oxidised by continuously circulating the oxidising gas and resulting fumes through the original charge, adding approx. 5% of the volume of air used per 100 gals, of original charge, and maintaining the volume of gases and fumes circulating through the material a t approx.
50 cub. ft. per 100 gals. H. S. G a r l i c k .
Manufacture of d isp ersion s of bitum inous sub
stances. N.V. D e B a t a a f s c h e P e t r o l e u m M a a t s . ,
Assees. of J. M . F a i n (B.P. 342,031, 15.11.29. U.S., 21.11.28).—Bituminous emulsions containing up to 75%
°f bitumen are prepared by adding to the water 0-25—
O'75% of mineral paste such as bentonite or clay and 0-fr—0-25% of soap or other material to lower the surface tension. T. A. S m i t h .
Treatm ent of aqueous d ispersions of bitu
minous substances. N.V. D e B a t a a s c h e P e t r o l e u m
Maats., Assees. of L. K i r s c h b r a u n ( B . P . 341,914.
21.10.29. U.S., 20.10.28).—The tendency of bituminous emulsions containing soap to break down prematurely in use when mixed with such substances as lampblack, asbestos, or cement may be overcome by treating these substances with trialkali phosphate or alkali hydroxide before adm ixture with the emulsions. T. A. S m i t h .
C atalysts for and m ethods of destructive hydro
genation [of carbonaceous m aterials]. H. W.
S t r o n g , and I m p e r i a l C h e m . I n d u s t r i e s , L t d . (B.P.
335,215—8, 19.6.29).—( a ) Heavy mineral oil and hydrogen under 250 atm. pressure are passed upwards through a steel vessel coated internally with nickel or tin and containing a number of similarly treated, hori
zontal, perforated trays between which are packed tinplate or nickel-plated iron discs or cylinders. The plated iron is activated by treatm ent with 5—10%
nitric acid containing 5% of carbamide, by immersion in borax a t 900—1000°, or by heating a t 350° in contact with paraffin wax. (b ) The reaction is carried out in the vapour phase a t 400—600° under a t least 10 atm.
pressure, (c) Alloys of tin with iron, copper, magnesium, or phosphorus having m.p. above 500° are used as catalysts in either of the above processes. Phosphor- bronze, gunmetal, and iron-tin alloys with less than 80% Sn are specifically claimed, ( d ) A porous catalyst such as bog iron ore or a dehydrated mixture of ferric oxide with 1—5% of alumina is used in addition to the metal catalysts mentioned above. A. R . P o w e l l .
Oil distillation. C. F . T e a r s , Assr. to T e x a s C o .
(U.S.P. 1,769,972, 8.7.30. Appl., 23.4.23).- T h e appar
atus consists of a still and a series of bubble-cap towers.
Oil is passed through a heat exchanger to the first bubble- cap tower and returned with the condensate to the still.
Condensate is withdrawn from each of the successive bubble-cap towers and passed through a heat exchanger, where it is reheated by the vapours from the previous tower. Vapours from the last tower are passed to a condenser. Sharp cuts are obtained. T. A. S m i t h .
Petroleum d istillation. A. McD. M c A e e e and
B . H. B a r n e s , Assrs. to G u l f R e f i n i n g C o . (U.S.P.
1,774,559, 2.9.30. Appl., 17.9.26).—Acid vapours formed by the distillation of petroleum oils containing acidic substances, e.g., aluminium chloride, are removed from the still a t the conclusion of the distillation by blowing a mixture of steam and caustic soda solution into the vapour space and allowing the vapours dis
placed to escape from the still. H. S. G a r l i c k .
Apparatus for converting hydrocarbons. G .
E g l o f f , Assr. to U n i v e r s a l O i l P r o d u c t s C o . ( U . S . P .
1,767,838, 24.6.30. Appl., 6.6.21. Renewed 21.2.29).—
Oil is passed through heating tubes mounted in a furnace where it is heated to cracking temperature, to an ex
pansion chamber to which are connected a vapour line and residue draw-off. Means are provided for separ
ately collecting the residual oil from the vaporising chamber and reflux condensate from the dephlegmator ; alternate draw-off lines direct the residue and reflux, together with the raw oil, back to the heating coil in predetermined proportions or direct such products to
storage. H. S . G a r l i c k .
Cracking of petroleum o ils. N.V. B a t a a f s c h e P e t r o l e u m M a a t s . , Assees. of W. J. P e r e l i s (B.P.
B r i t i s h C h e m ic a l A b s t r a c t s —B .
4 7 2 Cl. H . — Fu e l ; Ga s ; Ta b ; Mi n e r a l Oi l s.
343,286, 23.1.30. U.S., 14.2.29).—Increased yield in cracking is obtained by carrying out the operation in two stages. In the first the oil is heated to a tempera
ture at which coking would take place but for the fact th at the oil is highly turbulent and the heating carried on only for a short period. The oil is then passed to an evaporator, the portion containing asphalt being removed. The heavy fractions from a dephlegmator are returned for recracking in the second stage, being passed through a series of three heating coils.
T. A. S m i t h .
Cracking of petroleum oil. J. C. M o r r e l i , and H. P . B e n n e r , Assrs. to U n i v e r s a l O i l P r o d u c t s Co.
(U.S.P. 1,767,695, 24.6.30. Appl., 1.2.23. Renewed 4.6.29).—Oil is heated to conversion temperature by passage through a heating coil under superatmospheric pressure and discharged into an enlarged chamber, where the products are kept in turbulent agitation by means of paddles driven by a turbine utilising the expansive force of the vapours to supply the mechanical
power. H. S. G a r l i c k .
Cracking of [petroleum ] oil. J. S. H a r r i s o n ,
Assr. to S t a n d a r d O i l D e v e l o p m e n t Co. (U.S.P.
I,767,360, 24.6.30. Appl., 26.3.27).—Petroleum oil is heated to cracking temperature by passage through a coil set in a. furnace and retained under pressure in a digestion zone. From this zone it is continuously withdrawn in a single stream and discharged under reduced pressure and principally in thé vapour phase into a vaporising zone in which tar is separated from hydrocarbon vapours which are bubbled through oil in a stripping zone and partly condensed thereby. A fraction of the vapours containing essentially all the gasoline material passes to a rectifying zone and is separated into a condensate and an overhead distillate, which latter, together with feed oil, is continuously supplied to the stripping zone and continuously w ith
drawn and passed through the heating zone.
H. S. G a r l i c k .
Cracking of [petroleum ] oil. J. C. B l a c k (U.S.P.
1,770,098, 8.7.30. Appl., 16.11.26).—Oil mixed with aluminium chloride (2— 10%) is heated in a heat ex
changer to 315°, whereby all the unsaturated compounds are converted into saturated hydrocarbons. The mix
ture is then heated to cracking temperature in a cracking coil under pressure and passed to a dephlegmator in which the aluminium chloride is recovered.
T. A. S m i t h .
Cracking of hydrocarbon o ils. E. C. H e r t h e l ,
Assr. to S i n c l a i r R e f i n i n g Co. (U.S.P. 1,772,865, 12.8.30. Appl., 30.3.28).—Desulphurising material is added to crude oil before cracking. The mixture is preheated in the refluxing column and then fed into the vaporising chamber, where it is mixed with the material from the cracking coil. Vapours from the vaporising chamber pass to the refluxing column, the lightest being conducted to a condenser and the reflux circulated through the cracking coil. In this way the carrying over of the sulphur-removing material into the cracking coil is avoided and corrosion is minimised.
T. A. S m i t h .
Cracking of hydrocarbon o ils. II. L. P e l z e r ,
Assr. t o S i n c l a i r R e f i n i n g C o . (U.S.P. 1,774,291,
26.8.30. Appl., 7.6.27).—Oil is forcibly circulated from a bulk-supply drum through a battery of heating tubes and back to the supply drum. The heating tubes com
prise a series of banks of vertically arranged tubes situated in a flue with connexions between the upper ends, except the last in such series, and the lower ends of successive banks, the connexions being arranged externally of the flue. The first bank of heating tubes is arranged to make contact first with the heating gases in the flue, which communicates with a firebox at one end and a stack at the other. Means are provided for recirculating through the flue, together with fresh hot products of combustion, a portion of the heating gases escaping. Situated in the bulk-supply tank below the normal liquid level and between the connexions to and from the heating tubes is a bed of finely-divided solid material (e.g., fuller’s earth or coke). H . S. G a r l i c k .
Cracking of hydrocarbons. E. W. Isom and E. C. H e r t h e l , Assrs. to S i n c l a i r R e f i n i n g Co. (U.S.P.
1,774,600—2, 2.9.30. Appl., [ a - c ] 11.6.29).—( a ) Oil is passed in series through a vertical bank of tubes arranged in a flue with transverse baffles so th a t the heating gases which enter a t the top of the flue traverse the tubes several times. The oil is maintained under pressure in the heating coil and passed into a vaporising vessel which is also maintained under pressure. In (b) two or more series of heating coils, through which the oil passes in series, are mounted in the same flue, whilst the vaporising chamber is maintained under reduced pressure. In (c) the flue is divided by vertical baffles, so th a t the path of the gases is along the tubes, and is so arranged th a t the flow of oil is countercurrent to the
heating gases. T. A. S m i t h .
T reatm ent of petroleum hydrocarbons. R . C r o s s ,
Assr. to G a s o l i n e P r o d u c t s Co., I n c . (U.S.P. 1,775,067, 2.9.30. Appl., 2.8.24).—Cracking stock is passed con
tinuously through heating tubes, where it is raised to cracking temperature without any substantial vaporisa
tion or decomposition taking place, and the heated oil is passed to a digestion chamber in which the cracking reaction is completed. The oil is maintained sub
stantially in the liquid stage, and is passed to an evapora
tor, where the pressure is reduced and the lighter fractions are distilled off and passed to a series of dephlegmators and a final condenser. The reflux con
densate from the final dephlegmator may optionally be recycled to the condensate in the preceding dephlegmat- ing stage in order to distil off the remaining lighter fractions, or may be recycled from the final dephlegmat- ing stage to the unvaporised oil in the bottom of the evaporating stage in order to assist in preventing coking of the unvaporised oil. The reflux condensate remaining unvaporised in the initial dephlegmating stage is recycled through the system. H . S. G a r l i c k .
T reatm ent of petroleum o ils. F. G. R i n g and
P . G. P a r i s , Assrs. to B e t h l e h e m S t e e l Co. (U.S.P.
1,775,052, 2.9.30. Appl., 3.7.24).—Cracking stock is heated under pressure to decomposing temperature and the evolved vapours are removed and subjected to a series of selective partial condensations without loss of pressure by passing them countercurrently into heat- interchange immiscible relation with oil of high b.p.
