BRITISH CHEMICAL ABSTRACTS
B — A P P L I E D C H E M I S T R Y
DEC. 27, 1929.
I.—GENERAL; PLANT; MACHINERY.
Drying of solids. II. P. K . Sh e r w o o d (Ind. Eng.
Chem., 1929, 21, 976—980; cf. B., 1929, 153).—The rate of drying of a moist solid may be controlled by the rate of removal of vapour from the surface or by the rate of diffusion of liquid to the surface. Evaporation may take place from the surface or, in the later stages of drying, from the interior of the solid through a layer of solid which has already dried. A typical rate of drying curve has three periods. At first the rate of drying is constant, and is controlled by the rate of removal of vapour a t the surface. If parts of the surface of the solid are covered with material impervious to liquid or vapour the rate of drying may not be greatly reduced, as heat may be received by conduction or radiation a t these dry surfaces and may accelerate evaporation from the exposed surfaces. A t a critical moisture content drying proceeds at a falling rate.
This period may be divided into two parts. The reduc
tion in rate of drying in the first part of this period is due to decrease in the area of wetted surface, evapora
tion taking place through a dry layer a t certain points.
A change in the slope of the curve occurs again when the rate of diffusion of liquid becomes the controlling factor.
Equations are given for calculating the rate of drying in practice, based on the physical constants of the material and on atmospheric conditions.
C. J. Sm i t h e l l s.
Absorption. I. Very soluble gases. W . V. Hanks
and W. H . McAdams(Ind. Eng. Chem., 1929,21,103d—
1039).—Equations based on the two-film theory of Whitman (B., 1923, 913 a ) have been derived to express the effects of composition and temperature on the rate of absorption of a gas by a liquid. The absorption of ammonia by water has been investigated for gases con
taining 6—65 raol.-% of ammonia, and is in accordance with the authors’ equation. The nature of the gas used as carrier has a great influence on the numerical value of the absorption coefficient, which can be interpreted in terms of changes in film thickness (cf. A., 1925, ii, 106 :
B., 1925, 69). C. W. G ib b y .
Pa t e n t s.
Rotary-hearth furnace. E . S. Fa t k i n, Assr. to
We s t in g h o u s e El e c t r i c & Ma n u f. Co. (U.S.P.1,728,750, 17.9.29. Appl., 19.9.27).—A method of supporting tilting trays (for the goods) in an annular hearth furnace is described. B. M. Ve n a b l e s.
R otary [tubular] furnace. W . M. Du n c a n (U.S.P.
1,728,958, 24.9.29. Appl., 14.5.26).—A stepped combus
tion chamber is formed in the burner end of the furnace, the smallest diameter being adjacent to the fuel inlet.
Longitudinal air ducts are provided, which enter the furnace at the rising portions of the steps.
B . M. Ve n a b l e s.
[Grates for] furnaces. A . W . Be n n i s ( B .P . 320,347, 9.7.28).—Cast-iron fire-grate elements of the type which are supported on troughs conveying forced-draught air , are formed with tubes of stronger metal cast in them longitudinally ; several elements may be arranged in line, the tubes then being of different sizes, so th a t they can nest into each other. I t is also arranged for air currents to pass through the tubes. B . M . Ve n a b l e s.
D rying m ethods and apparatus. J. G . Ol s s o n
and F. I. E . St e n f o r s ( B .P . 299,838, 5.6.28. Swed., 2.11.27).—The material to be dried is conveyed through a long passage and subjected to transverse streams of drying medium circulated by a series of fans. -In the middle or some other part of the travel the circulating drying medium is heated by external heat, e.g., a steam coil ; from this zone the drying medium plus vapour is passed through a nest of tubes above the long drying chamber, thus serving to heat other transverse circu
lations (which become progressively cooler as the moist medium becomes cooler). There is in consequence always an available temperature difference, and the final temperature of the moist medium is so low th at practic
ally all vapour is condensed. The medium is then reconditioned for re-use either by further cooling by a water-cooled coil or by admixture of a proportion of the fresh cool air. B . M. Ve n a b l e s.
Cooling and degassing tow ers. F. K. T. v a n
It e r s o n and P. M. Ku y p e r s (B.P. 320,505, 20.9.28).—
A reinforced concrete cooling tower of flowing shape (as described in B.P. 108,863) is provided with one or more fans a t the throat, a preferred form being an aeroplane propeller on a vertical shaft.
B . M. Ve n a b l e s.
Condenser. J. A. Gi b b, Assr. to Pe t r o l e u m De r i v a t i v e s, In c. (U.S.P. 1,727,403, 10.9.29. Appl., 7.5.27).—Both inlet and outlet vapour ports are close to a pool of condensate, which is maintained out of contact with the cooling tubes. The heat from the vapour passing through the condenser is intended to revaporise low-boiling constituents from the pool.
B . M. Ve n a b l e s.
C rystallisation of substances that crystallise exotherm ically. Ap p a r e i l s e t Ev a p o r a t e u r s Ke s t- n e rSoc. An o n. (B.P. 301,496, 13.11.29. Fr., 2.12.27).—
For the direct production of dry crystals a hot saturated solution of a substance such as ammonium nitrate is subjected to strong agitation and a current of air. Two crystallising agitators may be fed alternately from one evaporator. B. M. Ve n a b l e s. 1035
B r itis h C tiom iaal A b s tr a c ts— B .
1036 Cl. I.— Ge n e r a l; Pl a n t ; Ma o i u n e b y.
Unit pulveriser. A. A. Ho l b e c k (U.S.P. 1,724,876, 13.8.29. Appl., 22.9.27).—The stationary pulverising element is attached to the removable cover plate of the
machine. B. M. Ve n a b l e s.
M ixer and conveyer. P. Th o m s o n(U.S.P. 1,731,953, 15.10.29. Appl., 16.8.26).—The loose materials are fed into one end of a worm-conveyer, which may have a diminishing pitch and be interrupted. The worm delivers the material to the interior of a screen, through which air is forced and from the exterior of which the material is removed pneumatically. B. M. Ve n a b l e s.
Pneum atic sorting of m aterials of different densities. P . S o u l a b y , and C om p, d e s M i n e s d e Bruay (B.P. 320,207, 10.9.28).—A shaking table or series of tables is provided with upward air currents in a series of zones alternating with dead zones without air. The skimmers for delivering the products are situated in the dead zones. The earlier skimmers remove lighter material sideways, whereas the later ones remove the heavier layer downwards and permit the lighter layer to pass straight on. B. M . V e n a b l e s .
Screening centrifuges. C. G. Ha u b o l d A.-G. (B.P.
310,512, 20.3.29. Ger., 28.4.28).—A centrifugal basket is driven by a sleeve shaft, within which is a solid shaft driven from the sleeve by step-up gearing. The solid shaft carries a worm-discharge device ; the distance between the periphery of the worm thread and the basket increases progressively in the direction of dis
charge of solid material. B. M. Ve n a b l e s.
B eating and/or m ixin g of liquids or sem i-liquids.
J.-W. and J. Mo r t o n (B.P. 318,851,8.6.28).—The appar
atus is suitable for whisking materials such as con
fectionery while under air pressure. The container is mounted on trunnions; the shaft for the beating device is brought through the walls of the container below the trunnion and is connected to the driving gear by dog
clutches. B. M . Ve n a b l e s.
Apparatus for treating liquids w ith gases, gases w ith liquids, and the like apparatus. G. K. Da v is ( B .P . 320,092, 4.7.28).—In an apparatus comprising a casing divided into compartments in each of which is a fanner for spraying the liquid which collects at the bottom of the compartments, gutters are arranged so th a t the spray caught on the vertical partition walls is diverted through the partition to the next compartment, thus producing a circulation of the liquid, which is controlled by varying the return openings below the liquid level. B.-M. Ve n a b i.e s.
Producing m ixtu res of liquids and ga ses. E. T.
Ch a m b e r s (B.P. 320,323, 3.7.28).—The apparatus
described can be used as a petrol carburettor, and with modifications is suitable for use as a blow lamp or fuel- oil atomiser. B. M. Ve n a b l e s.
Filter presses. Fi l t r e s Ph i l i p p e ( B .P . 318,794, 16.11.28. F r.y 10.10.28).—The plates are all to one pattern, one face being recessed and provided with feed port, the other being ribbed and provided with outlet port for filtrate ; frames are unnecessary, and the cakes are bounded on one side by the face of a plate itself and on the other by filter medium. B . M. Ve n a b l e s.
Filter. C. H . Lo e w, Assr. to Lo e w Fi l t e r Co.
(U.S.P. 1,726,035, 27.8.29. Appl., 13.3.24).—A number of circular plates are mounted on hollow hubs; each face of the plates has ribs and channels leading to the central passage through the hubs, and the periphery of each disc is provided with a rib, the cloth or filter medium being stretched over the faces of the disc by the action of friction rings applied each side of the peripheral rib. B. M . Ve n a b l e s.
[Laboratory] filter. R. B. Mil l a r d (U.S.P.
1.727.554.10.9.29. Appl., 2.10.28).—Liquid is siphoned from a high-level jar to the bottom of a filter jar. The latter is filled with filter medium and covered with a disc of paper through which the inlet pipe passes. The jar is fitted with a fluid-tight cap which secures the paper in place, and has an outlet for filtrate.
B . M . Ve n a b l e s.
Filtering devices. Soc. An o n, d e s Pr o c. R.
Au d u b e r t (S.A.P.R.A.) (B.P. 301,507, 29.11.28. F r .,
2.12.27).—The filtering medium comprises fibrous material stranded in the form of sheets and rolled up like a short wick. The block thus formed is cemented into a box-like structure, and the filtration is effected under very slight pressure or vacuum.
B. M. Ve n a b l e s.
Tank[-outlet] filter. C. G. Ha w l e y, Assr. to
Ce n t r i f i x Co r p. (U.S.P. 1,726,827, 3.9.29. Appl., 4.5.25).—A device attached to an outlet in the bottom of a tank causes the issuing fluid to whirl and deposit solid m atter in a sludge compartment. Two cocks operated by one rod are provided ; when the outlet cock for liquid is open the cock for discharge of sludge is closed and vice versa. B. M. Ve n a b l e s.
Filtering or like devices. H. A. Th o m p s o n (B.P.
318,821, 17.1.29. Addn. to B.P. 307,267 and 308,166 ; B., 1929, 499).—A method of forming the bearings for the geared scrapers of the prior patents is described.
B . M. Ve n a b l e s.
Apparatus for straining liquids. R. A. Bl a k e- b o r o u g h, J. Li n d s a y, and J. B . Bl a k e b o r o u g h ( B .P .
319,068,19.6.28).—The screen comprises a pair of endless travelling chains to which perforated screening plates are fitted in such a manner that the joints overlap.
B . M. Ve n a b l e s.
Means for separating solids from liquids. J. R.
Po w e l l, A s s r. to Ar m o u r & Co. (U.S.P. 1,729,547, 24.9.29. Appl., 20,9.26).—Sludge is drawn from the lowest corner of a tank having a sloping bottom and elevated by an ejector device to above the surface of a screen on which solid m atter is separated, the strained liquid running back into the tank. The power liquid for the ejector may be pumped from the upper part of the same tank. B. M . Ve n a b l e s.
Apparatus for separating liquids and solids.
H . C. Be h r (U.S.P. 1,727,855', 10.9.29. Appl., 10.9.27).
—A centrifugal screen is constructed after the manner of the blades of a centrifugal pump. The solid material is flung from the discharge end of the screen against a wall, from which it is removed by a series of movable
blades. B. M . Ve n a b l e s.
Separator of liquids from g a se s. T. F. Ro c h e s t e r,
Assr. to Ko r e c t Ai r Me t e r Co r p. (U.S.P. 1,731,061,
B r i t i s 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. 1037
8J 0.29. Appl., 14.12.27).—The apparatus comprises a -glass cylinder (or other casing) suitably closed at the ends. The outlet for gases is through the top and is surrounded by a depending flange. The inlet for fluid is through the bottom, up an internal pipe leading to near the top outside the depending flange but inside the casing. The outlet passage is smaller than the inlet.
B . M . Ve n a b l e s.
H.— FU E L ; G A S; T A R ; MINERAL OILS.
B riquetting of coke and sem i-coke dust, using coal as a binder. W. S w i e n t o s l a w s k i , B. R o g a , and M. C h o r ą ż y (Przemyśl Chem., 1929, 13, 465—473).—
The binding qualities of coal dust used for briquettes made of coke or semi-coke dust depend on its coking qualities ; non-coking coal is unsuitable for the purpose.
The source ofiTie coke or semi-coke dust used is of lesser importance, although better results arc obtained with semi-cokc derived from coking coal. Blixtures con
taining less than 30% of coal dust do not yield briquettes of satisfactory mechanical strength. The optimum pressure for the manufacture of briquettes is 200—400 kg./cm.2, whilst the optimum temperature varies from 380° to 440°, according to the variety of coal used.
R . Tr u s z k o w s k i.
Low-tem perature distillation [of coal] in the
“ Italian s y s t e m ” furnace. D. M e n e g i i i n i (Giorn.
Chim. Ind. Appl., 1929, 11, 391—399).—This furnace, installed a t th e communal gasworks at Genoa, is a modification by Scavia of the Piron furnace, the molten lead bath being omitted. I t comprises two superposed channels each 800 mm. wide and 10 m. long, the lower being 450 mm. and the upper 900 mm. high. The metal
lic conveyer consists of cast-iron plates articulated in chain fashion so as to form an endless band moved by toothed wheels at the extremities of the channels. The coal, ground to pass a 10-mm. sieve, is fed to give a layer about 15 mm. deep, and is distilled at 550—650°.
Both Thornley gas coal and lignite were distilled, the heating being effected by means of the ordinary gas made a t the works. One metric ton of the gas coal yielded 99-2 cub. m. of gas (calorific value 6700 kg.-cal./cub. m.), 667 kg. of semi-coke (6890 kg.-cal.), and 124-8 kg. of tar (8970 kg.-cal.), the gas consumed for heating being 230 cub. m. (4798 kg.-cal.). Of the calorific value of the coal consumed, 8-67% is obtained in the gas, 59-92%
in the semi-coke, and 14-55% in the tar ; total 83-14%.
One metric ton of dry Valdarno lignite gave 144 cub. m. of gas (2390 kg.-cal./cub. m.), 645 kg. of semi- coke (3640 kg.-cal.), and 4 3 'kg. of tar (8600 kg.-cal.), the heating gas consumed being 294 cub. m. (4752 kg.- cal.) ; 9 - 69% of the heating value of this lignite appears as gas, 66-13% as semi-coke, and 10-38% as tar.
T. H. Po p e.
Gaseous explosions. VII. Effect of lead tetra
ethyl on rate of rise of pressure. M. S. Carr and G. G. Br o w n (Ind. Eng. Chem., 1929, 21, 1071—1078;
cf. A., 1928, 1331).—The influence of lead tetraethyl on the rate of rise of pressure has been investigated for both slow-burning and fast-burning mixtures containing oxygen, nitrogen, and the following fuels : «-heptane,
«-octane, i’sooctanc, benzene, toluene, methyl alcohol,
ethyl alcohol, and ethyl ether. The effect of lead tetra
ethyl is independent of the chemical nature of the fuel, but depends largely on the type and rate of combustion and on the normal rate of rise of pressure in the un
treated fuel. In mixtures which give a maximum rate of rise of pressure below a critical rate, small additions of lead tetraethyl decrease the maximum rate of rise, but larger additions increase it. Above the critical rate of pressure rise, 0-1—1-0% by vol. of lead tetraethyl increases the maximum rate. The mechanism of the action of lead tetraethyl is discussed, and it is suggested th a t the decomposition products of lead tetraethyl are the active agents in retarding the rate of inflammation and rise of pressure, and th a t the accelerating action in fast-burning mixtures may be due to the explosive action of decomposition occurring in the flame front, the rate of inflammation being considered as greater than the rate of decomposition of the lead tetraethyl.
C. W. Gib b y.
Explosive lim its of industrial gases. J. Y e a w
(Ind. Eng. Chem., 1929, 21, 1039—1033).—The upper and lower explosive limits of mixtures of air with a number, of gaseous mixtures encountered in American city-gas manufacture have been determined. A small quantity of illuminating constituents reduces the upper limit from about 70% of gas to about 30%, but affects the lower limit to a much less extent. The upper limit is unaffected by large changes in the ratio of hydrogen to carbon monoxide, as their individual upper limits are close together, but is lowered by increasing the methane content. The limits can be calculated with considerable accuracy by the formula of Le Chatelier (Ann. Min.,
1891, 19, 388). C. W. G ib b y .
Ignition of firedam p. H. F. Co w a r d and R. V.
Wh e e l e r (Safety in Mines Res. Bd., Paper No. 53, 1929, 40 pp.).—The results of earlier work by these authors (B., 1926,179) on this subject are reviewed in the light of new data and old interpretations are confirmed or revised. Reference is also made to the results of subsequent work by Burgess and Wheeler (B., 1926, 114), Coward and co-workers (B., 1926, 426 ; 1929, 661 ; and A., 1928, 24), and by Bone and co-workers (A.,
1928, 248). C. B. Ma r s o n.
D issolved acetylene. W. Rimarski (Chem.-Ztg., 1929,53,725—727,746—748).—The volume of a cylinder of dissolved acetylene is occupied approximately as follows : porous mass 25%, acetone 40%, increase in volume of acetone due to absorption of acetylene 24%, allowance for expansion on heating to 65° 4-8%, safety space 6-2%. The porous mass should have a porosity of 70—80%, should not pack when the cylinder is dropped 100,000 times from a height of 11 mm. on to a steel plate, and should be only locally decomposed when a welding burner, fed by the gas from the cylinder, is played on to the wall of the full cylinder for 15—30 min. Apparatus for testing the internal and external ignition of the gas and its tendency to explosive decom
position is illustrated and briefly discussed.
A. R. Po w e l l.
Coking of pitch. J. P. Ko k t t n it z(Brennstoff-Chem..
1929, 10, 406—407).—The manufacture of electrode carbon by the distillation of coal pitch is briefly
B r i t i s h C h e m ic a l A b s t r a c t s— B.
1038 Cl. II.— Fu e l ; Ga s ; Ta r ; Mi n e r a l Oi l s.
discussed. The chief difficulty lies in the construction of a still capable of withstanding the high temperature, above 1000°, necessary in the final stage of the process, and has only been overcome by the recent progress in the manufacture of heat-resisting steels and refractories.
The process is interm ittent, the complete operation with a retort holding a 2750-kg. charge of pitch taking 30 hrs. The products are 58% of coke, 36% of distillate, and 6% of gas and loss. The distillate, mixed with other ta r oils, is utilised as cheap lubricating oil, heating oil, or impregnating oil. On admixture with other oils a solid is precipitated from which anthracene can be recovered.
A. B. Ma n n i n g.
[Purification from phenol of] effluents from coke ovens. M. Pr ü s s (Gas- u. Wasserfach, 1929, 72, 791—
801).—The river Emscher is estimated to receive 10,000 tons per annum of phenols in the form of coke-oven effluent*. The work of Fowler on the bacteriological purification of such effluent has been repeated by the river authority, and an artificially aerated culture pre
pared which requires only 2 cub. m. of filter material per cub, m. of effluent. The effluent must be diluted in the ratio 1 : 4, and a time of contact of 2 hrs. pro
vided. This Emscher filter is a t work a t one colliery and is described. The temperature and values require careful control, and 60 cub. m. of air/cub. m. of effluent are required. I t is, however, too expensive for general use. The use of the effluent for coke quenching is impracticable owing to the nuisance caused by vapours.
Under these circumstances four phenol recovery plants were erected in the Emscher basin and commenced work at the end of 1926. These operated the “ P o tt- Hilgenstock ” benzol process and were partly financed by the river authority. As the benzol takes up only 1% of phenols distillation of the benzol is too expensive and the phenols are removed by alkali washing. Costs are discussed, and it is claimed th at a t the present market price for carbolic acid a large coke-oven plant could work this process a t a small profit. Some indirect advantages are also obtained; e.g., the effluent water can be used for works’ purposes. The American Koppers process is described, but it is not believed th a t it will be adopted in Germany. A combination of partial extraction and bacteriological treatm ent may be desirable. For the effluent from lignite distillation benzol treatm ent is inapplicable, but experiments are proceeding using a heavy oil of b.p. 320—350°. This effluent is even more objectionable and difficult to deal with than th a t from coke ovens. In the discussion on this paper the use of activated carbon for phenol recovery in place of benzol
was advocated. C. Ir w i n.
Crude oil produced in the Salt Creek Field, W y
om in g. H. P. Ru e and I. N. Be a l l (U.S. Bur. Mines Tech. Paper No. 449, 1929, 27 pp.).—An apparatus for distilling 10-gal. charges of crude oil is described, and both steam and coking distillations were made in an effort to prepare distillates comparable with those obtained in refinery practice. Firstly, the crude oil was distilled with sufficient steam to prevent cracking, and the resulting distillates were fractionated and further -treated. Secondly, the crude oil was distilled to coke without steam, and, after removal of the coke from the
still, the entire distillate was recharged and distilled with steam as in the first process. The final yields in the two processes were, respectively : gasoline 33 • 0, 41 • 0 % ; kerosene 5 ■ 0 ,2 • 3% ; gas oil 18 • 0, 26 • 4% ; non- viscous lubricating oil 8-3, 11-5% ; viscous lubricating oil 4 • 7, 2 • 5% ; gear oil 3 • 8%, n i l ; foots oil 7 • 0, 5 • 5% ; wax 15-8, 4 -1 % ; asphalt 1-1%, n il; total coke and losses 3-3, 6-7%. H. S. G a r l i c k .
Evaluation and cracking of gas oils. R. H. G r i f f i t h (J.S.C.I., 1 9 2 9 ,4 8 ,2 5 2 — 2 6 3t).—The mechanism of gasification of gas oils has been studied in a furnace containing a silica tube heated electrically, the per
manent gas produced being burned in a Boys calori
meter and all results expressed on a thermal basis. I t is found th at the rate at which oil is passed through the cracking zone influences the results, there, being an optimum speed on either side of which loss of efficiency occurs. The changes do not, however, take place entirely on the hot surface, but the proportion of gas reaction varies with the surface: volume ratio of the apparatus. The decrease of efficiency at very low rates of oil feed is not due to further decomposition of gaseous hydrocarbons, but to other processes involving absorption of large volumes of hydrogen. When the experiments are carried out in an atmosphere of nitrogen, instead of with the addition of hydrogen, much lower figures are obtained. The temperature of cracking is also im p o rtan t; the best results are obtained a t about 750°, lower temperatures giving higher tar yields and higher temperatures leading to formation of free carbon. Com- parative tests have been performed under standard conditions on 31 oils from a very wide range of sources, and a t the same time these oils have been analysed with respect to their content of unsaturated, aromatic, naphthene, and paraffin hydrocarbons (cf. B., 1929, 841).
Results varying from 1 ■45 to 0 • 50 therms per gallon were obtained, and it is found th at a gas oil can be valued by means of chemical analysis, as the straight-chain hydro
carbons in it are of far greater importance than those having a cyclic structure. Further preliminary work on the influence of b.p. of the oil, and on the nature of the tars produced, is also described. The conclusions drawn from these small-scale experiments have been examined on two water-gas plants during normal operation;
the methods employed in obtaining the necessary measurements and in calculating the results are detailed, and it has been found th a t the same factors are involved in producing good or bad results ; the number of gallons of oil injccted into the carburettor and the temperature a t which the cracking vessels are operated are of primary importance. Measurements have been made of the sur
faces and volumes involved, and the figures obtained show th a t the same type of reaction is involved as th at observed in laboratory experiments. The amounts of methane and gaseous defines produced, and of hydrogen absorbed, per gallon of oil are shown for various operat
ing conditions on the two plants.
T herm al treatm ent of natural ga s. D. S. C h a m b e r l i n and E. B , B lo o m (Ind. Eng. C h e m ., 1929, 2 1 , 945— 949).—Natural gas was thermally treated in tubes of silica, steel, copper, iron, nickel, monel, and clay. Between 500° and 900° the various tubes had
B r i t i s 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. 1039
different effects in regard to converting methane into benzene, naphthalene, anthracene, acetylene, etc. Fused silica, clay, copper, and moncl metal do not catalyse methane and ethane to any great extent. Copper gives the highest yields a t the lowest temperatures, but the metal is consumed after a very short time in use.
Silica gives high yields at intermediate temperatures, and is the most im portant material studied, as it is not changed by heat or by products of the thermal treat
ment. Iron and nickel readily decompose methane into its elements, but these metals are rapidly disintegrated by the reaction. The effects of temperature, surface, dilution, and other factors were studied, and various units are discussed ranging from apparatus of laboratory size to a semi-commercial installation. Experiments show it is the carbon, formed as a result of the decomposition of natural gas a t.450° and above, which has a selective activity in the conversion of paraffins into aromatic com
pounds etc. This activity is easily destroyed by partial oxidation or by the formation of carbon-metal com
pounds, graphitic carbon being the final result. By a comparison of the results of these thermal treatments with th a t of gas manufacture in the by-product coke oven, assuming th a t the gases have reached an equi
librium, the practical yield of benzene has been obtained from natural gas amounting to 27-0—40-0 litres per 1000 m.3 of gas treated. The optimum temperature of benzene formation varies for each material and the method of carbon formation thereon. When the con
centration of hydrogen has attained 50—60% of the volume of the gas being treated the oil yield becomes
negligible. H. S. Ga r l i c k.
A nalyses of som e natural gasoline gases before and after treatm ent. H. C. Al l e n (Ind. Eng. Chem.
[Anal.], 1929, 1, 226—227).—The results are given of the analysis of three natural gasoline gases before and after treatm ent to remove gasoline. A comparison is made between the results obtained by combustion analysis and the method chosen, viz., fractionation by means of liquid air, and analysis of the fractions by combustion methods, the results, in general, differing considerably. H. S. Ga k l ic k.
Relation between physical characteristics and lubricating values of petroleum oils. E . D . Ries
(Ind. Eng. Chem. [Anal.], 1929, 1, 187—191).—The tests for- physical characteristics are discussed in the light of their relation to lubrication. Neither gravity nor colour bears any relation to lubricating value.
The A.S.T.M. cold test shows a rough parallelism to the actual point at which flow ceases, but the numerical values mean little. W ith Pennsylvania oils, high carbon residue as found by the Conradson test is due not to high wax content but to these oils being less volatile than those in the same viscosity range made from other crudes. In general, the removal of wax increases the Conradson carbon number of the dewaxed oil ; the wax itself forms no carbon in the test. Flash and fire tests indicate nothing as regards lubricating power and give inaccurate data on evaporation. Only a small amount of a relatively volatile component will materially lower the fire and flash values without causing undue percentage loss by evaporation. A vacuum-distillation
test giving a volatility curve similar to the Engler curve for gasoline is of greater value. The temperature- viscosity coefficient does not entirely depend on the nature of the crude oil, but may be modified by the method of refining, and is lowest of all in vacuum- distilled paraffin oils. As yet no completely satisfactory test for oiliness or for resistance to oxidation has been devised, and the need for certain new tests is advocated.
H. S. Ga r l i c k.
Reaction between lubricating oils and phos
phorus pentoxide. C. C. Fu r n a s (Ind. Eng. Chem.
[Anal.], 1929, 1, 185).—The use of yellow phosphorus to eliminate oxygen from a closed circuit in which nitrogen was circulated a t room temperature by means of a rotary blower led to the pump heating up and sticking owing to the formation of a thick gum on all friction surfaces. Tests showed this residue to contain considerable phosphorus and to be formed by phosphorus pentoxide dust being carried over by the pump and reacting at 30—35° with the lubricant. If water were added to the oil the gum dissolved and did not form again even at 100°, provided sufficient water was present to form a separate phase. H. S. Ga r l i c k.
Variation of viscosity of [lubricating] oils with tem perature. E. W. De a n and G . H. B. Da v is
(Chem. Met. Eng., 1929, 36, 618—619).—In a scheme to formulate the viscosity-temperature coefficients of oils in simple manner it w a s. found th a t the general relationship between viscosities (Saybolt) at the standard temperatures oT 100° F . and 210° F. could be expressed by Y = a + k c + c x 2, in which Y and x are the vis
cosities a t 100° F . and 210° F . , respectively. The constants are characteristic of the series of oils. A system of so-called “ viscosity indexes ” indicates the viscosity-temperature coefficients of oils on a scale in which oils having a large change of viscosity are taken as zero and oils with only small changes in viscosity
as 100. C. A. Ki n g.
O xidising lubricating oil b ottom s. A. D. De m c h e n k oand C. N. Ob r y a d c h ik o v (Neft. Choz., 1928,15, 360—366).—The material was blown with air at 235—
252°, and the composition of the gases, distillate, and residue was determined as the oxidation proceeded.
Ch e m ic a l Ab s t r a c t s.
Setting point of som e m ineral oil m ixtures. J.
Te r p u g o f f (Petroleum, 1929, 25, 1213—1214).—
Deviations between the observed and calculated setting points of mineral oil mixtures may be positive or negative according to the nature of the constituent oils. Positive deviations occur with certain blends of Russian, Texas, and Pennsylvanian oils, and negative with certain Russian, Texas, and mid-continent oils. In some cases the setting point of the mixture is lower than those of the initial oils. Since mixtures of oils of the same origin give differences between observed and calculated setting points which lie within the limits of experimental error, it follows th a t mixtures of oils of various origins undergo a change in their properties.
With positive deviations some oils are rendered more viscous, although there is no change in viscosity a t 20°, 50°, and 100° ; with negative deviations some oils are rendered more liquid. The greatest deviations occur
B r i t i s h C h e m ic a l A b s t r a c t s— B .
1 0 4 0 C l . I I . — F u e l ; G a s ; T a r ; M i n e r a l O i l s .
with Texas oils, which become more liquid with rise of temperature. Such oils, the viscosities and setting points of which are decreased in mixtures, change their liquid state very quickly as the temperature rises.
I t is assumed th a t at, e.g., 20° some hydrocarbons of those oils are only present in the colloidal state, and with rise of temperature, or oil mixing with oils of other origins, these hydrocarbons pass into ordinary solutions.
W. S. E. Cl a r k e.
Alcohol fuels for use in internal-com bustion en gines. J. G. Ki n g and A. B. Ma n n in g (J. Inst.
Petroleum Tech., 1929, 15, 350—368).—Experiments were conducted to determine the limiting factors in the preparation of mixed alcohol fuels and their behaviour in an ordinary standard petrol engine.
Absolute or 98 • 6% alcohol is miscible in all proportions with petrol, but on the addition of water to the mixture petrol separates until a t a certain concentration, depending on temperature, none remains in solution.
Marked separation is caused by 1-8% of water, and in a 1 :1 solution of petrol and absolute alcohol the amount of the separated layer a t 0° may be 36% of the volume of the petrol present. The miscibility limits and limiting percentages in stable mixtures with 95%
alcohol of seven petroleum spirits are given over the temperature range +15° to —10°, and vary over a fairly wide range. The ranges of miscibility at 15° of 95% alcohol and of a Persian petrol extend from 0 to 1-1% and 63-5 to 100% of alcohol by vol., the lower range being so limited as to be negligible.
B.S.R. benzine and Persian spirit differ from others in having higher solubilities but steeper solubility curves, so th a t the solubilities are less a t —15° than a t 0°.
Absolute alcohol and benzene are miscible a t all temperatures above the m.p. of the latter. The alcohol- benzcne mixtures which have initial crystallising points a t 0° and —10° contain, respectively, 25-1 and 59-0%
of alcohol. In the examination of ternary mixtures of alcohol, benzene, and petrol, the limiting amount of petrol in 100 vols. of mixture containing 50 vols. of alcohol was 39-5 vols. a t 15° and 31 vols. a t —5°.
W ith 2% of water present these values were con
siderably lowered. Mixtures containing 50% of benzene were stable a t —5° irrespective of the proportions of the other constituents as regards separation of solid benzene. The water separation limits for 92% and 95% alcohol are given. W ith mixtures containing 50% of petrol no clear solution was obtained at 0°, the critical point being about 3°. W ith 72% alcohol no clear solution was obtainable a t 15°. The limits of stability for varying amounts of petrol were deter
mined. Experiments in which pure benzene was replaced by commercial 90’s benzol and the alcohol by power methylated spirit each showed a reduction in miscibility range, showing th a t the limits of safety for a mixed motor fuel would be narrowed by the use of less pure alcohols and benzol. The limits of miscibility of power methylated spirit and 90's benzol in different petroleum spirits are tabulated. The above experiments were repeated using motor spirits recovered from the low-temperature carbonisation of bituminous coal with results of the same character. Phase diagrams for petrol-benzol-alcohol mixtures are given and serve to
show up the difference in aromatic content^. o [ ' the petrols. From a Series of engine tests on mixed fuels of the above type, one containing the maximum quantity of petrol safe at —20°, a second the maximum quantity of alcohol, and a third petrol containing the maximum amount of alcohol in solution, the following conclusions were arrived a t : (1) Both petrol-alcohol-benzene mixtures are suitable for use in petrol engines without any alteration beyond enlarging the carburettor jets.
(2) The petrol-alcohol mixture cannot be used satis
factorily. (3) Detonation was not observed with any of the fuels. (4) The volumetric fuel consumption increases with the volume of alcohol in the fuel.
(5) The thermal efficiency obtainable is similar to th a t of petrol. (6) The difference between mixture strengths giving maximum economy and the theoretical mixture strengths is greater with these fuels than with petrol.
(7) The mixture strength required to obtain maximum economy is nearer the limiting strength for smooth running for these fuels than with petrol.
II. S. Ga r l i c k. Pa t e n t s.
Recovery of condensates from coal-distillation ga ses. Ba r r e t t Co., Assees. of S. P. Mi l l e r (B.P.
294,106, 6.7.28. U.S., 16.7.27).—The hot gases from coke ovens or gas retorts are cooled to a limited extent, e.g., by spraying ammonia liquor into the goose-necks and collector main, and are then cleaned from suspended pitch particles by means of an electrical precipitator.
By suitable regulation of the temperature a t which the gases are cleaned, pitch of low carbon content and of any desired m.p. may be collected in the precipitator. The cleaned gases are cooled to a sufficiently low temperature to condense from them an oil suitable for use as creosote o il; or the cooling may be carried out in two stages giving, respectively, a creosote oil and a lighter tar acid oil. The gases are further treated in known manner to recover ammonia and benzol therefrom.
A. B . Ma n n i n g.
Settings for vertical retorts used in the pro
duction of gas etc. Dr a k e s, Lt d., and J. W. Dr a k e
(B.P. 320,448, 4.8.28).—Vertical retort settings in which the waste combustion gases are withdrawn from the lower end of the setting have the uptake flues leading from the producer so arranged th a t a portion of the combustible gases can be admitted to the uppermost combustion chamber while the remainder is led to a lower combustion chamber, situated preferably about one third the height of the retort from the top. Second
ary air is admitted to the combustion chambers in amounts necessary to give the desired heating effects.
A. B. Ma n n i n g.
Apparatus for production of producer g a s. L. U.
d e To y t o t (B.P. 320,441, 28.7.28).—Air and steam are introduced into the centre of combustion of the fuel through a conduit projecting axially downwards into the producer. The air passes through an injector device arranged to draw in a quantity of steam proportional to the amount of air passing. The steam is supplied from a water reservoir which communicates with a boiler surrounding the nozzle through which the air and steam enter the producer. A. B. Ma n n in g
B r i t i s h C h e m ic a l A b s t r a c t s— B .
Cl. II.-— F u e l ; G a s ; T a b ; M i n e r a l O i l s . 1041
H u r d l e s f o r washing gas e t c . W. So m m e r (B.P.
320^375, 14.1.29).—Thin wooden boards are arranged -'parallel to one another and spaced by slats running crosswise between the boards. Two connecting rods pass through each set of spacing slats and through the boards. Wedges passing through slots in the ends of the connecting rods serve to clamp the boards and slats together. [Stat. ref.] A. B. Ma n n in g.
Treatm ent of crude oils, tars, bitum inous residues, etc. L. Bo l g a r (B.P. 319,673 and 319,718, 23.3.28).—(a) Crude oil, tar, or pitch, etc. is heated with an oxidising agent, e.g., sulphuric acid, acid sludge, a t 120—200°. The precipitate which forms is separated from the liquid and further heated at a higher tempera
ture, preferably with the addition of a fluxing agent Such as anthracene oil, until the acids are decomposed.
The product forms an artificial asphalt, the physical characteristics of which' may be smtably modified by the addition of tar, pitch, etc., or of sand or other filling materials, (b) The starting material is mixed with the acid and heated a t a temperature above 1S0°, stearine pitch being added before or/and during the acid treat
ment. The mixture is then further heated with the addition of filling materials such as sand, stone meal, asbestos. The product is pressed while hot. I t is particularly suitable for the manufacture of insulating materials, roof coverings, etc. [Stat. ref. to (a).]
A. B. Ma n n i n g.
Manufacture of hydrocarbons and the like from coal, tars, m ineral oils, etc. I. G. Fa r b e n i n d. A.-G.
(B.P. 296,431, 8.8.28. Ger., 1.9.27).—When high- boiling oils are hydrogenated at 1000 atm. and at high temperature products of intermediate b.p. are obtained.
At 200 atm. a larger proportion of light, products is obtained, whilst a t 20 atm. gas, light products, and carbonaceous residue without products of intermediate b.p. are obtained. Hydrogenation of suspensions of coal, tar, etc. in stages is therefore advocated. The initial material is first hydrogenated in the liquid phase a t 200—1000 atm. The intermediate oils produced are then treated a t 20—50 atm. in the gaseous phase whereby benzine is formed exotherm ically; catalysts may be used. Thus an American crude oil (40—50% boiling above 350°) is treated with hydrogen a t 200 atm. and 450° in the presence of a chromium-molybdenum catalyst. W ithout any separation the product is expanded into a second chamber.maintained a t 20 atm.
and 480°. The mixture of gas and vapour obtained from the second chamber is cooled under pressure, and deposits a liquid consisting of benzine of high anti
knock value and about 25% of lamp oil (b.p. above 200°). Only a small proportion boils above 235°, and ... there are no losses due to formation of gas and coke.
Very heavy asphaltic oils are best treated in three stages a t p i^sures of 1000, 200, and 20 atm., respectively.
_ ^ T. A. Sm i t h.
D istillation, cracking, and hydrogenation of oils, tars, etc. ^ qhlenveredlung A.-G. (B.P. 293,430, 6.7.28. Ger.. 6.7r27).—The raw material is atomised by being fed on to a series of rapidly rotating discs, and is simultaneously heated by circulating hot gases and vapours through the apparatus. The issuing gases and vapours are passed through a superheater and recircu
lated through the atomiser, p art being withdrawn periodically and passed to a condensing system. The process may be carried out in the presence of a hydro
genating gas, and, if necessary, under pressure.
A. B. Ma n n i n g.
Production of olefines and other hydrocarbons.
J . Y. Jo h n s o n. From I. G. Fa r b e n i n d. A.-G. (B.P.
320,211, 14.9.28. Addn. to B.P. 301,775; B„ 1929, 120).—Granular porous substances, e.g., pumice, slag, are impregnated with tars, mineral oils, distillation residues, etc., and are then passed through a chamber heated to a high temperature, as described in the main patent. The granular material is re-impregnated and used again. When necessary, the coke deposited thereon is gasified in a suitable producer.
A. B. Ma n n i n g.
Production of artificial rock asphalt. J . Kl e in. (B.P. 320,357, 9.7.28).—Asphalt, pitch, oily distillation residues, etc. are emulsified with an aqueous solution of naphthenic acid or one of its salts, and a mineral filling substance, e.g., lime flour, is then added. The greater part of the excess emulsifying agent is removed in soluble form, and the remainder rendered harmless by precipitation as an insoluble metallic salt.
A. B. Ma n n i n g.
Production of gasoline hydrocarbons. W. K.
Le w i s, Assr. t o , St a n d a r d Oil De v e l o p m e n t Co.
( U .S .P . 1,730,152, 1.10.29. Appl., 3.2.23).—A gas containing gasoline hydrocarbons (e.g., natural gas) is stripped of its gasoline content by passing up a tower countercurrent to a suitable absorption liquid (i.e., a liquid which is non-volatile under the existing conditions and miscible with the hydrocarbons). The gas is introduced a t an intermediate point of a contact zone for gas and liquid, the absorption liquid entering above the gas inlet and, a t least in part, adjacent the top of the contact zone. This zone is heated near the bottom by means of a coil through which passes the hot, stripped absorption oil, and is cooled at the top by means of cooling coils. W. S . E. Cl a r k e.
Treatm ent [cracking] of hydrocarbons oils.
C. P . Du b b s, Assr. to Un i v e r s a l Oi l Pr o d u c t s Co.
(U.S.P. 1,729,307—8, 24.9.29. Appl., [a] 26.2.20,
[b] 24.9.23. Renewed [b] 3.8.28).—(a) Oil is heated to above 427° at a pressure high enough to prevent destruc
tive distillation. I t is then flashed, the flash chamber being at atmospheric pressure ; almost complete separa
tion into vapour and coke is thereby obtained. Vapours are fractionated and all insufficiently converted material is fed continuously to the charge stream, (b) The residual oil from the reaction chamber of a cracking process is removed and introduced into a coking still.
The pressure on the still is released and the oil coked by superheated steam. W. S. E. Cl a r k e.
D istillation of hydrocarbon oils. R E. Wil s o n,
Assr. to St a n d a r d Oi l Co. (U.S.P. 1,731,479, 15.10.29.
Appl., 15.1.25).—The fractionating column of a still contains a number of superposed closed cooling con
duits, which are provided with valves and are connected in parallel with a pair of manifolds. Condensate accumu
lating in a collecting pan half-way down the cooling conduits is passed outside the column. F. G. Cl a r k e.
B r i t i s h C h e m ic a l A b s t r a c t s— B .
1042 C l. V.— Fi b b e s ; Te x t i l e s ; Ce l l u l o s e ; Pa p e b.
V .- F I B R E S ; TEXTILES; CELLULOSE; PAPER.
Strength o f cellulose [pulps]. K. R i e t h (Papier- Fabr., 1929, 27, G93—694).—Variations in the results of strength measurements on pulp, carried out by the method laid down by the German Strength Commission, may amount to 25%, and are attributed to differences in the moisture content of the paper strips tested. Since strength depends on the moisture content, and the latter depends on the relative humidity (R .H .) of the atmos
phere in which the strips are conditioned, it would appear th a t all the tests were not carried out on strips fully conditioned at 65% R.H. In order to overcome this difficulty it is suggested th a t tearing-length results should be referred to the moisture content of the paper and not to any specific R.H. Methods of determining R.H. are discussed. Further errors arise in the determination of the degree of beating of the pulp. They may be due to the quantity of pulp taken for examination, the use of different sieves, non-uniformity of the apparatus used, and to the time taken for the operation. New sieves often give results which differ from those given by old sieves of the same number. The effect of different beating machines on the degree of beating, time required to reach a certain degree of fineness, and the relative merits of ball mills and hollander beaters are discussed.
B. P. Ri d g e.
Rate of decom position of viscose solutions- 0 . Faust (Ber., 1929, 62, [/?], 2567—2573).—The viscose solutions containing 5% of cellulose and 5% of sodium hydroxide are very greatly diluted with water containing phenolphthalein and brought into a flask fitted with a small dropping funnel. The acid is intro
duced through the funnel as rapidly and uniformly as possible, followed by an excess of 0 • lJV-iodine. The residual iodine is determined by titration. The interval between decolorisation of the phenolphthalein and addition of iodine is the measured time of decomposition.
The acids used are acetic, phosphoric, oxalic, hydro
chloric, sulphuric, and sulphuric treated with 5% of sodium naphthalenesulphonate previously condensed with 0-5 mol. of formaldehyde. An appreciable difference is not observed between the rates of decomposition of viscose from ripened or unripencd alkali-eellulose. The greatest rate of decomposition is observed at the com
mencement of the addition of acid. In 3 sec. the concentration of viscose with 8-54% maximal xanthate content diminishes by 1 -8—2-0% with acetic and about 2-4% with sulphuric acid. The further course of decomposition is rather more rapid with stronger than with weaker acids, but the difference gradually dis
appears. The rate of diffusion does not enter into the question since the solutions are vigorously shaken during the addition, and are so dilute that a membrane is not produced- I t is shown to be possible to esterify more than one hydroxyl group of the C6H10O5 unit of cellulose by carbon disulphide. II. We e n.
Purified wood fibres as a papermaking m aterial.
R . H. Rasch (Bur. Stand. J. Res., 1929, 3, 469—506).—
The chemical purity, colour, durability, and permanence of purified wood fibres and of papers made from them have been compared with the corresponding properties of papers made from rags and other fibres. Artificial
ageing tests (heating at 100° in dry arid moist air for 72 hrs.) show th at the relative permanence may b e
measured by determining the decrease in the a-cellulose content. Like purified rag fibres, purified wood fibres undergo little change in this test, and thus should,show similar good resistance to the yellowing effects^ of natural ageing, A high degree of hydration is detri
mental to the permanence of a paper, but inert mineral fillers tend to increase the resistan ce to agein g. Addition of glue and starch sizes to the pulp retards chemical deterioration. These results indicate th a t papers made of purified wood fibres are suitable for permanent
records. A. R. Po w e l l.
Hydration, paper form ation, and strength.
G, Porrvik (Svensk Pappers-Tidn., 1929, 32, 191—196 ; Chem. Zentr., 1929, i, 2935).—The degree of hydration of bleached sulphite-cellulose is determined by the external capillary water, the internal capillary water, and the fibre-wall water. The union of the fibres in the production of paper is essentially a colloid-chemical adhesion phenomenon, and not a felting process. The effect of milling is discussed. A. A. Eldridge.
Pa t e n t s.
Production of fibre articles. M. M. Fr o s t (U.S.P.
1,726,818, 3.9.29. Appl., 15.7.27).—The fibre is pulped in water, an adhesive, e.g., rosin soap, is added, the water expressed, and the fibre after being moulded under high pressure is dried and impregnated with molten sulphur in a closed vessel which is first exhausted and then subjected to pressure. F . R. En n o s.
Manufacture of tracing cloth. Po t t e r, Bo a r d- m a n& Co., Lt d., and P. Ha m il t o n(B.P. 320,071,3.7.28).
—Ordinary oil-starch or wax-starch tracing cloth is passed through a bath of oil, such as olive oil; containing an oil-soluble blue dye, e.g., chrysoidine-blue, and after expressing the superfluous oil is treated with a volatile solvent containing shellac; the solvent is allowed to evaporate and the cloth polished by rapidly rotating
rollers. F. R. En n o s.
Copper oxide-am m onia cellulose solution for spinning artificial silk by the stretch-spinning process. A . Ha r t m a n n, A s s r. t o Am e r. Be m b e r g Co r p. (U.S.P. 1,728,565, 17.9.29. A p p l., 5.2.25. G e r.,
24.6.24).—T o r e d u c e -th e s p i n n i n g t e m p e r a t u r e r e q u i s i t e , f o r o b t a i n i n g t h e b e s t p r o d u c t , c e llu lo s e is d is s o lv e d in a m i x t u r e o f p u r e c o p p e r h y d r o x i d e a n d a m m o n ia w i t h s u b s e q u e n t a d d i t i o n o f s o d iu m s u l p h a te . F. R. En n o s. ,
Manufacture of copper oxide-am m onia cellulose solutions for production of artificial silk. A. C a r p -
m a e l. From I. G. F a r b e n i n d . A.-G. (B.P. 320,069, 28.6.28).—The cellulose used for dissolving in the cupram- monium solution is the commercial variety, consisting of thick sheet or board which has been neither chemically pretreated to modify its solubility nor treated with water to cause it to swell. F, R. En n o s.
Carbonising the organic constituents of sulphite- cellulose lye. C. G. Sc h w a l b e (U.S.P. 1,731,354, 15.10.29. A ppl, 4.4.27. G er., 13.3.26).—Less than 3-6 kg. of sulphuric acid are added to 100 litres of the spent lye, and the mixture is heated at about 1.80° and 10 atm.
for 8 hrs. H. R o y a l - D a w s o n .
