Numerical simulation of the thermal explosions of gaseous methyl isocyanide

Abstract

A numerical simulation of the gaseous thermal explosions of methyl isocyanide and of mixtures of methyl isocyanide with methyl cyanide, is described. For all spherical vessel sizes from 0.3 to 13 dm³ and for temperatures from 330 to 370 °C, the computed explosion limits agree with the experimental values to within ca.± 0.2 Torr for critical explosion pressures in the range 2–11 Torr. For explosions of undiluted methyl isocyanide, the usual Frank-Kamenetskii critical parameter δ_c is ca. 3.95, and the reasons for its departure from the standard value of 3.32 are examined. Most important is reactant consumption, followed by gas flow away from the centre of the vessel, and variation of thermal conductivity with temperature; of lesser importance is the variation of the activation energy with pressure or of heat capacity with temperature.