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VIII. SYNTHESIS OF AROMATIC HYDROCARBONS
Kaiser Wilhelm Institute für Kohlenforschung had carried out laboratory experiments on synthesis of aromatic hydrocarbons from mixtures of carbon monoxide and hydrogen. It is known that, in general, mixtures of CO and H2 produce straight-chain paraffins at relatively low temperatures, alcohols in the range 300-400°C. and aromatics in the range 475-500°C.
This latter temperature range of 475-500°C. was therefore used for making aromatics, and the pressure was 30 atmospheres. Catalysts used were oxides of chromium, molybdeum, or thorium, with 5 to 10 per cent K2CO3 added to reduce carbon formation. A synthesis gas of 1:1 ratio of carbon monoxide and hydrogen were used.
The yield of liquid product was very poor, being only about 10 grams per cubic meter of synthesis gas, much of the synthesis gas going to methane and carbon, and there was also a substantial residue of unconverted gas. The liquid product contained about 50 per cent of aromatics, mostly toluene, xylenes, and higher, and about 50 per cent naphthenes.
Because of the unpromising character of the results, this research project had been temporarily abandoned by Kaiser Wilhelm Institute. (3) (17)