Auto-Ignition of Reactive Solid Materials

Self-heating and hot-spot formation occur frequently in many beds of reactive solids due to exothermal oxidation reactions, e. g. piles of coal, bark, hay but also in adsorbers operated with activated carbon. As a consequence of self-heating auto-ignition may take place which may cause destruction of the plant and facilities. In order to predict the self-heating behaviour of a system it is necessary to take into account not only the material properties but also apparatus specific parameters (e. g. geometry) and the operation conditions (e. g. temperature, gas flow). To be able to consider all relevant parameters the transient, 2D - computer code SEBOSS (SElf-heating Behaviour Of Stored Solids) has been developed: The computer code SEBOSS is based on the differential equations for the conservation of mass, energy and momentum which are solved by the method of lines. In order to provide the main material properties for the computer simulation a differential reactor has been designed for the determination of the chemical kinetics. Furthermore an apparatus for the measurement of the effective heat transfer coefficient has been developed which is based on a stationary two plate principle.