Toluene Mono-nitration in a Semi-batch Reactor

 

 

Li-Ping CHEN, Wang-Hua CHEN*, Ying LIU,
Jin-Hua PENG and Rong-Hai LIU


Dept. of Safety Eng., Sch. of Chem. Eng.,
Nanjing Univ. of Sci. & Tech. (NUST),
Nanjing, 210094, P R China

Abstract: Toluene mono-nitration in a semi-batch reactor was investigated with
reaction calorimeter (RC1). The mixed acid HNO3/H2SO4/H2O (wt%) was used
in proportion 13/66/21, which is similar to industrial parameters. The exothermic
rates at different reaction temperatures were compared, and then the curves of heat
generation rate after dosing were analyzed. The Maximal Temperature attainable
by runaway of the desired Synthetic Reaction (MTSR) under different conditions
were calculated for the course hazard evaluation. The results showed that the
average reaction heat of mono-nitration was between 169.07~177.11 kJ mol-1,
and the special heat of reactant was about 2 kJ kg-1 K-1. Average Ea of second
order kinetic was about 30 kJ mol-1, and reaction rate was 10-4 mol s-1 l-1 order of
magnitude when the strength of sulphuric acid was about 73.5%. It was also found
that when temperature or stirring speed increases, the potential heat accumulation
decreases.

Keywords: toluene mono-nitration, apparent activation energy, semi-batch
reaction, thermal hazard

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