FINDING FOOD

Evening Post, Volume CX, Issue 137, 8 December 1930, Page 9

FINDING FOOD

WORK OF THE CHEMIST!

RESEARCH SAVED THE WORLD

SHORTAGE OF NITEOGEN;

Although mineral oil doea not occur, in Britain, recent research has showa that the deficiency can, at any rate partially, be made good, and that under certain conditions coal can be convert* ed 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 th» gas industry. This lew temperature carbonisation yields, together with gaf and a soft coke admirably suitable foe,domestic uses as a smokeless fuel, ft tar from which both fuel oils and fin* 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 less than 40001b per square inch with hydrogen gas derived from water in presence of certain metals. VALUABLE FUELS. .'. By varying the conditions and previously gasifying the coal with atmospheric oxygen, a series of valuabla 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 serv« as the basis of purely chemical processes. Thus, for example, methyl alcohol (wood-spirit), a substance used in hundreds of modern 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 synthetic production, of acetic acid, industrial alcohol or benzine, which latter compound has hitherto only been obtained from coal tar. X 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 in importance. la the early days of the gas industry thin by-product was not only neglected as a, waste material, but was even regarded as a nuisance. LIQUID OOLD. 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-established industries of foreign trade rivals. Although the photosynthesis 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 sup» ply of nitrogen is essential, in soma 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 soil, 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 ev«tf passed, for science has solved the riddW of how to deal with the inert nitrogen gas of the air and convert it into aa active state" in which it forms the basi» ■ of the most valuable fertilisers. SAFEGUARDING THE EMPIRE. The process now In general uso con* sists in uniting together nitrogen and hydrogen gases at high temperature tai form ammonia. The reaction is anothej example of modern "high pressure'chemistry, and is carried out in speck ally 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 industral 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 annually, constitutes a national enterprise of the highest magnitude, and places us in a position of definite security regarding the nitrogen requirements of 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 grassland the grazing period caa be lengthened, more cattle can be maintained, and thus our meat and milk supplies increased.