Phenol, synthesis World production

At the end of World War II, Fischer-Tropsch technology was under study in most industrial nations. Coal can be gasified to produce synthesis gas (syngas), which can be converted to paraffinic liquid fuels and chemicals by the Fischer-Tropsch synthesis. Liquid product mainly contains benzene, toluene, xylene (BTX), phenols, alkylphenols and cresol. The low cost and high availability of crude oil, however, led to a decline in interest in liquid fuels made from coal. 

In 1865 just prior to Kekule s synthesis of phenol, Joseph Lister (1827-1912) was experimenting with carbolic acid as an aid to antiseptic surgery which he had pioneered. A mixture of crystallised carbolic acid and shellac (lac plaster) was employed in the finally adopted mode of application. The requirement of phenol for the manufacture of picric acid during the Boer war and other uses resulted in a demand which soon outstripped the resources of phenol/cresols available from coal distillation. Synthetic phenol thus became a potentially important intermediate. The lengthy processing involved in the separation of phenol and the isomeric cresols led to the desirability for specific syntheses. In 1978 of the world production of phenol only 3% came from coal sources by extraction of the mixed phenols (about 1.5% in coal tar) with 10% sodium hydroxide, acidification with carbon dbxide and separation. Phenolic compounds are also formed during catalytic cracking processes in the petroleum industry. There are historically six industriai processes for the production of synthetic phenol, variously from benzene and toluene, some of which are also applicable to the cresols and the dihydric phenols. 

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