Thermal screening of materials is a vital part of hazard assessment in the chemical industry. There is the need to identify
the worst potential hazards and to further investigate these scenarios. Several screening methods are presented, and the subject
of ramped temperature screening tests is studied in detail. Methods for the detection of exothermic reaction 'onset' temperatures
are given. It is shown that, under some circumstances, the temperature data obtained during a simple controlled ramp heating
experiment can be used to estimate the expected temperature rise that would occur under adiabatic conditions and the heat
of reaction. The use of the data to obtain nth order kinetic parameters is also demonstrated. Data obtained using the Thermal Screening Unit (TSU) are compared to those obtained using other forms of apparatus. Heats of reaction and kinetic data have also been calculated
and compare very well with data obtained using much more sophisticated adiabatic calorimeters.
Authors:C. Gonzales, J. Sempere, D. Nomen, and S. Waldram
This paper explains why directly agitated test cells are sometimes required in order to obtain good adiabatic calorimetry data that can be used with confidence to predict large scale plant behaviour. Experiments for methyl methacrylate polymerisation are reported. Simple procedures are presented for calculating genuine thermo-kinetic parameters from data which includes energy dissipation from the stirrer drive system.