Advanced kinetic modelling of biomass gasification based on optimum height of the reduction zone

A mathematical model was built to estimate the working parameters of a downdraft gasifier, in which a full kinetic model at each zone of the gasifier was described. The model deals with a wide range of biomass types with elemental composition ranges of (38≤C≤52) %, (5.5≤H≤7) %, and (36≤O≤45) %. This model is able to predict gas composition, temperature and height of each zone, as well as temperature, velocity and pressure distribution at reduction zone with heating value of product gas and cold gas efficiency. It also gives prediction of tar amount in product gas and a full design condition of a downdraft gasifier which are not available in any previously published works. The final results, which proved to be in a good agreement with experimental works under different working conditions of biomass type, moisture content, and air to fuel ratio, were based on a new approach calculating optimum height of the reduction zone