EXAMINATION OF THE RESIDENCE TIME DISTRIBUTION IN A HIGH-PRESSURE THERMOGRAVIMETRIC SYSTEM

The literature describes experimental methods to investigate, and mathematical models to describe, the flow conditions in simple systems. For these simple systems there is good agreement between the experimental results and calculated data. For more complicated flow patterns however, these theoretical models cannot be used. In this paper it is shown that an empirical mathematical model can be used to describe the residence time distribution (RTD) in a 'non-trivial' flow system. This mathematical model describes the flow conditions (RTD) in a pressurized thermogravimetric system from 1 to 100 bar, with a set of constants for each pressure. The residence time distribution is used to correct the measured gas yield versus temperature curves from non-isothermal thermogravimetric experiments, to obtain results unaffected by the apparatus.