WORK OF THE CHEMIST

Timaru Herald, Volume CXXXIII, Issue 18764, 31 December 1930, Page 16

WORK OF THE CHEMIST

RESEARCH SAVED THE WORLD. Although mineral oil does not occur in Britain, recent research has shown that the deficiency can, at any rate partially, be made good, and that under certain conditions coal can be converted into liquid fuels, writes Professor J. M. Heilbron, of Liverpool University, in the “Daily Mail,” explaining “How the chemist saved us from starving.” One process whereby this is being effected is by heating coal in specially designed retorts at temperatures considerably below that employed in the gas industry. This low temperature carbonisation yields, together with gas and a soft coke admirably suitable for domestic uses as a smokeless fuel, a tar from which both fuel oils and fine motor spirit can be produced. A second promising line along which research is developing has for its object the total conversion of coal into liquid fuel. In this process coal, either finely powdered or suspended in some suitable oil, is heated under pressures of not Jess than 40001 b per square inch with hydrogen gas derived from water in presence of certain metals. By varying the conditions and previously gasifying the coal with atmospheric oxygen, a series of valuable liquids and gases, such as methane and ethylene, can be prepared, many of which may be utilised as direct fuels or readily converted into such. Alternatively, the products may serve as the basis of purely chemical processes. Thus, for example, methyl alcohol (wood-spirit), a substance used in hundreds of modem operations, but hitherto only obtainable by the expensive and wasteful wood distillation process, can now be economically synthesised directly from carbon monoxide and hydrogen. Again, by diverse processes acetylene can be cheaply prepared from coal, and this gas can be utilised for the synethetie production of acetic acid, industrial alcohol -or benzine, which latter compound has hitherto only been obtained from coal tar. It is, indeed, no exaggeration to say that the development of this applied chemistry, wherein operations are carried out under high pressure conditions previously undreamt of, opens up a new epoch of synthetic achievement of unlimited possibilities. Of all the products of high temperature coal carbonisation, coal-tar ranks as second to none importanqe. In the early days of the gas Industry this by-product was not only neglected as a waste material, but was even regarded as a nuisance. Although outwardly a black and uninviting liquid beloved and abused in turn by motorists, in the hands of the chemist it has proved a veritable El Dorado of wealth. Huge industries, embracing the manufacture of dyes, medicinal products, photographic chemicals, explosives, resins, etc., depend for their existence on coal tar. Many thousands of valuable substances are made from it, and yet day by day research reveals still further uses for this product. Before the war the fine chemical trade, which is based practically wholly on coal-tar, had almost ceased to exist in this country. To-day it once again plays an increasingly important part in our industrial life, and gives employment to thousands of workers. Despite its vigour, however, it is still young, and we must guard it carefully yet awhile if we are to maintain it against the long-establish-ed industries of foreign trade rivals. Although the photosythesis of sugar marks the first stage in the evolution of the plant, other materials besides carbon monoxide and water vapour are required for its growth and development. Of these a constant supply of nitrogen is essential, in some soluble form, such as ammonium sulphate or codium nitrate.

Under the conditions pertaining today, Nature by herself cannot supply sufficient assimilable nitrogen to maintain a fertile sou, and as a consequence artificial means have had to be adopted to make good the deficiency. It is probably hardly realised that the problem of ensuring against a shortage of nitrogen fertiliser was one of the most urgent with which the chemist has been confronted. But for scientific research the world would within a comparatively short space of time, owing to depletion of Chilean nitrate, have been in danger of starvation by the failure of its crops. To-day all such danger is for ever passed, for science has solved the riddle of how to deal with the inert nitrogen gas of the air and convert it into an active state in which it forms the basis of the most valuable fertilisers. The process now in general use consists in uniting together nitrogen and hydrogen gases at high temperature to form ammonia. The reaction is another example of modern “high pressure” chemistry, and is carried in specially designed resistant steel chambers, the raw constituents being air, water and coal. Simple as this statement of the method of production of ammonia seems to be, the translation of the process from the laboratory to the industrial stage ranks as probably the greatest triumph of modern chemical and engineering science. The marvellous plant in operation at the Imperial Chemical Industries works at Billingham, where hundreds of thousands of tons of soluble nitrogen are manufactured arinuallv, constitutes .1 national enterprise of the highest magnitude, and places us in a position of definite securii" regarding the nitrogen requiremen. the Empire. With the advent of cheap ammonium sulphate vast possibilities for the expansion of agriculture in this country can be envisaged; arable lands can be fertilised to provide richer crops and poor pastures stimulated into good grazing lands. Again, by the intensive treatment of our grass land the grazing period can be lengthened, more cattle can be maintained, and thus our meat and milk supplies increased.