Formal Kinetics and Modeling

Many working groups have modeled the performance of diesel particulate traps during the past few decades. Concentrated parameter models (CSTR assumption) have been applied for the evaluation of formal kinetic models and model parameters. The formal kinetic parameters lump the heat and mass transfer effects with the reaction kinetics of the complicated reaction network of diesel soot combustion. Those models and model parameters were used for the characterization of the performance of different filter geometries and filter materials, as well as of the performance of a variety of catalytically active coatings and fuel additives [58], 

The pressure drop over a soot filter and the concentration versus time function gained from an experiment in a closed gas-loop system are shown in Fig. 15.5. 

The inflection point of the oxygen respectively the carbon dioxide concentration (maximum of the respective first deviations) is often referred to as the ignition temperature , which is commonly used as a simple measure for benchmarking work on catalyst activity or filter performance. 

Regeneration curves for different diesel particulate trap geometries and materials are shown in Fig. 15.6. 

The regeneration curves are often derived from CO2 generation data in closed-loop laboratory systems. It is assumed that the formal kinetics of soot combustion may be described by the oxidation of carbon with oxygen. A typical formal kinetic model comprises two parallel reactions of n-th order  

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