Other sources of aromatic hydrocarbons

While olehos can be obtained industrially by synthesis from shorter molecules, or from functional molecules, aromadc hydrocarbons are not yet produced individually by th two methods. They are produced in a mixture by dehydrocydizadon as part of naphtha catalyuc reforming, and are likely to be produced shortly by the aromatization of short-chain alkanes. 

Moreover, aromatics may be of non-petroleum origin. In fact about 10 per cent of the aromatics consumed today worldwide are obtained from coal 

During the conversion of coal to coke required for the production of pig iron, crude gases or coke oven gases are formed, together with benzols and tars (coal tars). The carbonization balance depends on the volatile matter index of the coal feedstock. On the average, one ton of dry coal yields  

Benzols are essentially produced by the purification of crude gas, with a small part produced by tar distillation. Coke oven gas has the following average composition  

It is no longer employed as a city gas, but is used as a fuel in a number of steel complexes, or as a raw material for ammonia synthesis. 

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