Old British method

Some features of the British method which was developed during the 1914 1918 period are worth mentioning. One of them was the use of toluene derived from petroleum (Borneo petroleum), as well as toluene from coal. 

Petroleum fractions distilling from 95°C to 115°C containing 55-60% of toluene, were used. The remainder constituted aliphatic hydrocarbons which would not nitrate under the conditions of the process. The MNT thus obtained, containing some petroleum components, was purified by distilling off the petroleum fraction. 

Detoluation. Another characteristic feature of this method was the extraction of higher nitrated toluene derivatives, dissolved in the spent acids. The latter were conveyed to denitration and distillation (concentration) only after the nitro compounds present in them had been extracted with nitrotoluene, an operation which was called detoluation . Primarily it consisted in stirring the spent acids, heated to 75-80°C with a quantity of crude MNT, amounting to one quarter of the acid volume. A slight amount of nitrotoluene became nitrated due to the presence of the unreacted HN03 in the spent acid. 

Later the detoluation operation was combined with partial nitration of MNT to DNT, by adding to the spent acid a certain quantity of nitric acid from the recovery operation (denitration). 

Detoluation consisted of two stages, carried out in a detoluator and in a super-detoluator (Fig. 80). 

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Washing of TM and preparing it for final purificaiion Old British method Detoluetion... 

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