No abstract

No abstract

To study the thermal explosion of liquids a low pressure autoclave has been built. The first stage of a thermal explosion, the thermal runaway, has been studied. Evaluation of the temperature-time history results in kinetic data. Comparison with other thermal methods shows that the reliability of the method is better than with DTA.Tertiary butylperoxybenzoate has been investigated in the temperature range of 330 K to 440 K. Decomposition starts with a short period of autocatalysis, up to a conversion of about 0.05. The subsequent deco#nposition can be described by a second order process in the first instance and by a first order process in the last resort. Induced decomposition occurs up to a conversion of about 0.95.The description of exploding liquids is usually based on detonation or deflagration. However, many liquids do not detonate when shocked by an explosive and do not deflagrate when ignited by a flame. Yet an explosion can occur after a prolonged period of heating. This is called thermal explosion and is characterized by a considerable degree of self-heating or thermal runaway of the liquid before the larger part of the explosion energy is released. Actually an explosion comparable to a deflagration or detonation does not occur until after a drastic change in the physical state of the liquid by the thermal runaway process.The theory of thermal explosion [1][2][3] is concerned with the competition between heat generation of the reacting system and heat dissipation by conduction, convection and radiation from the reacting mass to the outside. The tendency of the reacting system to rise above the ambient temperature due to self-heating is opposed by both the heat transfer to the surroundings and the heat consumption of the reactant. It is worth noting here that the thermal explosion theory tries to account for the onset of the explosive behaviour of energetic substances during storage or during batch-wise operation. Hence, a continuously stirred tank reactor is not considered.To evaluate the temperature-time history for a thermal explosion and to gather reaction kinetic data a low pressure autoclave has been built. Tertiary butyl peroxybenzoate (TBPB) has been chosen as a model substance [4].

No abstract

No abstract