Benzol.

Progress, Volume III, Issue I, 1 November 1907, Page 31

Benzol.

Benzol is a product of the distillation of hard coal. For a long time the only source was the coal tar of the gas works, which contained from 1 to 1.5 per cent, benzol and toluol together. This source was not sufficient to supply the demand in the chemical industries. A new source was opened out in the manufacture of coke by distillation. In this process tar. benzol, and ammonia were made as by-products. In 1904 Germany had 19,309 stills, of which 9110, or 47 2 per cent., delivered these by-products ; the rest did not. The amount of benzol produced was but small, being only about 0.5 per cent. In that year there were made about 60,000 tons of benzol from twelve million tons of coal. Of these 60,000 tons the greatest part — about 75 per cent. — was used in the d>e industry as the source of nitro-benzol, anilin, etc., for in the coal-tar dye industry Germany now has the lead. In 1906 the exportation of that country in anilin and other coal tar products amounted to 116.6 million marks, equalling, say, £5,500,000. The gas industry also used benzol for improving the quality of gas of low illuminating power. A mixture of two-thirds coal gas and one third water gas, such as now generally made by the gasworks, is usually enriched by about forty grams of benzol per cubic metre. This uses up 6000 tons per year in Germany alone. Not only in gas-works is it employed, for benzol is also used for increasing the heating power of furnaces, etc., and it is also utilised in open-air burners, such as are used for street lighting. In all, for these purposes about 1000 tons per year are used. The same material is also used as a solvent for fats, resins, guttapercha, and indiarubber ; also to remove varnishes and in the extraction from bones of oil for oil-cake. The consumption for these purposes amounts to between 3000 and 4000 tons per year. There are, therefore, left for the purpose of automobiles only between 3000 and 4000 tons !