(189b) Understanding the Effect of Fill-Ratio on Thermo-Kinetic Data

Understanding the effect of fill-ratio on thermo-kinetic data

 Dr Swati Umbrajkar

 Chilworth Technology, 113, Campus Drive, Princeton, NJ 08540 swati.umbrajkar@dekra.com , Phone: 609-799-4449

 Abstract

In order to safely scale up a process from the laboratory to plant scale, adiabatic tests are performed to simulate worst case scenario. Small scale adiabatic tests have a higher phi-factor or thermal inertia factor compared to a plant-scale reactor. To compensate for the high phi-factor, the data obtained from small scale adiabatic calorimeters is corrected for the phi factor. This phi correction is well understood and routinely used.

However, this well-known method to correct bench-scale experimental data for “thermal inertia” – the Phi factor – does not consider the effect of vaporization on thermo-kinetic data. The volumetric fill ratio of a calorimeter is an important parameter and is directly related to the vaporization-effect. The rate of temperature rise is sensitive to the fill ratio as well. Researchers have determined through modeling that a high fill ratio is desirable, to get more-accurate temperature rise data for a tempered exothermic reaction. A low fill ratio requires a significant Phi correction and could also give a misleading thermo-kinetic interpretation of a plant-scale reactor.

This paper examines the effect of fill ratio on the thermo-kinetic data. Experimental techniques like accelerating rate calorimetry will be appraised to study the thermo-kinetic behavior of a synthetic aromatic monomer. Testing will be performed at various fill ratios of the test cell. The effect of fill ratio on the onset temperature, rate of temperature and pressure rise will be studied.