FUTURE SUPPLIES

Evening Post, Volume CXXI, Issue 142, 17 June 1936, Page 26

FUTURE SUPPLIES

LUBRICATING OIL

SYNTHETIC REPLACEMENT

Our ever-increasing use of powerdriven machinery carries with it, naturally, an increasing demand for fuel, | but less apparent, however, is the concomitant growing demand for lubricants, says a writer in the Melbourne "Age." It is estimated that the consumption of lubricating oil in England is a little more than 100,000,000 gallons a year— j about one-tenth that of the petrol consumption. It is a fortunate circumstance that,, while the discovery of petroleum made possible a great extension jn the use of power-driven machinery, it supplied also an accompanying and liberal supply of suitable lubricant. Before the advent of petroleum most lubricating oils and greases were of vegetable and animal origin—for example, tallow, whale oil, palm oil, castor oil—whereas now, with the exception of castor oil, these oils are of quite minor importance from the point of view, of quantity, and in many cases would be quite unsuited to certain engines. Again, even if they were suitable and readily available in quantity, another serious objection to their use as lubricants would certainly arise from the fact that the chief animal and vegetable fats are either actual or potential foodstuffs, and we may be quite certain that the average man would place a higher value on the requirements of his stomach than, on those of the crank case .of a motor-car. ANXIETY ABOUT SUPPLIES. It is well known that in recent years a good deal of anxiety has been felt concerning the depletion of petroleum supplies. Such a depletion would constitute a serious, although not insurmountable, setback to our mechanical world, from the point of view of fuel supply, but it would be more serious in curtailing our supplies of lubricants. Readers are familiar with the fact that many countries are seriously concerned with the problem of obtaining fuel oil from sources other than petroleum—from, for instance, coal—and it becomes evident that the problem involves that of a supply of lubricating oil, since our supplies of this latter come mainly from petroleum. Further it might be surmised that the solving of the major would at the same time I effect the solving of the minor problem, but actually the situation is much more delicate than it at first appears. It is reasonably easy to. produce fuel oil [from coal, but the production of a first'class lubricant is another matter. Two oils which are almost identical in gross chemical composition and in ordinary physical properties such as density and viscosity, will generally be closely alike in calorific power, but not necessarily in lubricating power. In other words, they may contain the same elements in nearly the same proportions, but their constitution—that is, internal arrangements of their atoms—may be quite different, and constitution as opposed to mere composition seems to be one i main factor on which lubricating value depends. CHALLENGE TO THE CHEMIST. Such a problem, correlation of be-' haviour with composition and constitution, is a well-known one in chemistry, and is always a challenge to the chemist. Commenting on the present state of affairs, a prominent chemist said recently that we were in an unhappy state of ignorance. After twenty years' ■work on this subject he did not personally know of one definite specific hydrocarbon which had been isolated and characterised—and which was known to exist in the lubricating cil fractions.

The obvious step which suggests it,self is that of making a complete analysis and a subsequent examination of the constituents of a good oil. Unfortunately, lubricating oils from petroleum are mixtures of perhaps as many as a dozen individual compounds sufficiently alike to defy our present means of analysis. One is, therefore, thrown back on the synthetic method of attack, an actual building up of an oil, and it is recognised that this method of procedure is at present not only the academic solution of the problem, but probably also the best way of ensuring practically an artificial supply of lubricants. Already some progress has been made in synthesising oils from certain selected chemicals, gases of quite simple constitution occurring in the gaseous product obtained in the distillation of coal. The gist of the method is to select at starting what are known I as' unsaturated compounds—that is, compounds of such a type that two will combine with one another and produce only one, more complex, third compound—that is, produce one individual substance and not a mixture, for, as stated above, it is complexity which hitherto has delayed our progress in elucidating fundamental data connecting chemical composition with lubricating efficiency, FILMS ON SURFACES. Assuming a supply of pure synthetic material to be available, it will be possible, also, to obtain more definite information about another phase of the general problem of lubrication, the. problem of what takes place between the old and the lubricated surface. A useful amount of general knowledge exists concerning the behaviour of thin films on , surfaces, but such knowledge deals rather with the phenomena observed than with the substances involved in the process. Apparently some sort of chemical action takes place between oil and surface, and a more exact knowledge of this action can be obtained' only by the use of pure compounds in place of mixtures.