How the Petroleum Industry Has Developed
Page 35
If you've noticed an error in this article please click here to report it so we can fix it.
The Leading Points From a Particularly interesting Paper Read in January Before the Royal Society of Arts by James Kewley, M.A.,
F.I.C., Einst.P.
MANY interesting facts regarding the petroleum industry are contained in the paper, " Evolution in the Petroleum Industry," read recently by Mr. J. Kewley, M.A., before the ,Royal Society of Arts.
The author refers, in this connection, to the Institute of Petrolee with its membership in many lands, and to that great authoritative book, " The Science of Petroleum," published by the Oxford University Press, which affords evidence of the immense interest in the industry displayed in this country, despite the fact that we produce practically no crude oil. , The production of erode oil presents ever-increasing difficulties. In older' fields deeper wells may have to be drilled, whilst new fields must be found and developed in new and often unexplored territory. In drilling, amazing progress has been made. In 1895 the deepest well was 1,200 ff., whilst in 1940 the depth reached was 15,000 _ft.
Analytic and Chemical Processes Used
It is particularly in the working up of crude oils that the industry has displayed its special character. It is an analytic rather than a synthetic process. From a complex raw material there are produced diverse produCts,by processes mainly of a physical nature, In the refining, however, chemical methods are often employed. Of recent years, moreover, the industry has entered the field of chemical manufacturing, and now makes from its basic hydrocarbons a variety of products other than hydrocarbons.
Crude oils contain a great variety of components, ranging from the simplest methane to the complex semi-solid or even solid, asphaltic bitumens.
The kerosene which Drake's well of 1859 yielded in high percentage, and of good burning quality, was the cause of the first 'oil rush and remained the Chief product up to about 1910. Crude oils from other fields, however, did not giVe such a big yield. This added to the difficulties which the refiners . Were experiencing in disposing of theirother products, the unwanted lighter fractioas and residual . fuel oils:They attempted to obtain higherYields by including as many as they dared of the Tighter fractions, also of the• heavier, thus producing .a kerosene dangerously inflammable and of poor burning
quality. Legislation put an end to that gime. Keroiene has fallen from its high estate, . and whereas the yield in 1900 was nearly 60 per cent., it is now little over 5 per cent.
When, about 1910, the Le, engine becitne an important factor, crude Oils of great diversity of character'were _ being produced in Russia, the Dutch East Indies; Rumania, Burma and Poland, but as the U.S.A. is by far the largest producer, figures from there are of the most interest. In 1900 the production of crude oil was 8,714,000 tons, and 8,000 motor vehicles were registered; in 105 the production rose to 136,000,000 tons and registered vehicles to nearly 28,000,090. Thus in 1915 there were nearly 16 tons of crude oil per vehicle, and in 1935 less than 5 tons,
How .waS this result achieved? The most obvious way was by reducing the volatility by including fradtiOns previously embodied in the kerosene. Naturally, the final boiling point of the motor spirit began to rise. From 140 degrees C. it Crawled up to 225 degrees C. Engine makers were thus forced to design better carburetters and .adopt methods of heating the intakes.
However, the method of increasing the volatility of the spirit and the yield was available, including natural gas from the wells and gases or uncondensed vapours from the distillation plant. Thus the incorporation of pentane and butane increased the volatility. By 1919, motor spirit contained 3 per cent, of these light fractions; now it may contain some 7 per cent.
Cracking Process's • Marked Progress
, The, help given by this means was, however, small, but the probleen Was salved by the develOPment of the crackdig process; by means of Which hydro' carbons. of high molecular weight and boiling point are broken down by thermal decomposition under high pressure to a lower molecular weight and boiling point within the usual motorfuel range. Cracked spirits, however, are not as stable as those distilled from natural' crudes, and require special
refining methods. The process is flexible as to yield and character of product. The refiner thus developed a process which enabled him to control, within wide limits, the yield and quality of spirit made from any given crude. As a result of these endeavours, the yield of spirit from the crude has been increased over four-fold.
Whilst the demand was rapidly rising, the efforts of vehicle makers were directed to improving efficiency
by raising compression ratios. This created a call for motor spirit of higher anti-knock value, and so far back as 1920 investigation as to the relationship between the chemical composition of the fuels and their anti-knock value was started by Ricardo. At a later date it was found desirable to express the anti-knock value in terreS of mixtures of highand low-grade standard fuel, those selected being normal heptane as zero and one of theiso-octanes considered as 100. A standard. engine, lthown as the C.F.R. (Co-operatiwe Fuel Research), was adopted, and the anti-knock values expressed in terms of octane numbers. Considered in this way, the quality of motor fuel in the U.S.A. has rjsen'in the following manner:-1931, r8; 1933, 67; 1935, 70; 1940, 73.
Improved Methods for Octane Control The cracking processes now -used are very flexible, sometimes having three furnaces, so that cuts from the distffia.tion of residue can be separately cracked under different conditions of
temperature A catalytic process of cracking has also been designed, which enables greater control of the final octane number to be obtained.
When the oil engine came on the ,scene, suitable fuels were ready. Some idea of the demand for these is given by figures for the sale of oil engines (expressed in terms of h.p.) in the U.S.A.;-1915, 86,000; 1939, 2,726,000,
Methane and ethane, because of their low critical temperatures, cannot conveniently be used as liquids, but dry or natural gas containing methane, ethane, propane, butane and pe.ntane is used as gaseous fuel in the refineries and for industrial purposes, and to some extent for the manufacture of hydrogen by thermal decomposition, also for the production of the valuable carbon black employed largely in the rubber-tyre and printing-ink industries.
Another interesting product is known
as "bottled gas." Butane and propane liquefied by pressure at ordinary temperatures are distributed in steel bottles and used for cooking and lighting purpOses, particularly where coal
gas is not available. They' are also used for the cutting and welding of metals, the bottles being more easily transportable than heavy acetylene cylinders.