CHAPTER IXTNT MANUFACTURE
TOLUENE
TOLULENE is the principal raw material for the manufacture of TNT. It is produced
from light oil and from the gases obtained by the dry distillation of coal.
In some oil producing countries (e.g. U.S.S.R.), toluene is obtained from aroma-
tic fractions of petroleum or by aromatization of heavy petroleum hydrocarbons
by cracking processes (in Poland studies on aromatization of petroleum were
carried out by K. Smolenski [1] between 1922 and 1939). In war-time the demand
for toluene for nitration was so large, that these two sources were inadequate.
During World War II new methods of toluene manufacture on an industrial scale
were developed starting from benzene and methyl alcohol and from n-heptane.
The reaction of toluene formation from benzene and methyl alcohol can be
represented by the following scheme:
(1)The reaction proceeds at a temperature of 340-380°C and at pressure of 30-35
atm in the presence of zinc diphosphate on silica catalyst.
Since under these conditions higher homologues of toluene (xylenes, etc.) can
readily be formed, a large excess of benzene is used for the process. The yield of
toluene obtainable by this method (calculated on methyl alcohol) is close to the
theoretical one.
In Germany, during World War IL nearly 4000 tons of toluene were produced
monthly by this method.
The method of preparation of toluene from n-heptane was mainly developed
in the U.S.A. It is based on the following reaction:
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