Thermal utilization of meat and bone meals. Performance analysis in terms of drying process, pyrolysis and kinetics of volatiles combustion

A development of technology of thermal utilization requires a thorough knowledge of the physicochemical properties, as well as kinetics of combustion of volatiles and char. Due to waste management regulations the meat and bone meal (MBM) is regarded as biofuel constituting one of the alternatives to fossil fuels in the energy market. MBM is a heterogeneous material that may consist of several different fractions. The extensive analysis of issues related to its thermal conversion, including moisture evaporation, pyrolysis and gas burning, is reported in the paper. The samples derived from fallen animals which have undergone thermal decomposition in the plant of Jezuicka Struga S.A. (Poland) were examined. The research was carried out using a unique test stand. The study of drying process showed that the results for various samples differ to a great extent. It was observed that the time of drying process is proportional to the moisture content. Pyrolysis, being a thermal treatment itself, as the first step in gasification processes needs to be evaluated as a potential source of energy recovery from meat-and-bone meal. The conversion of animal waste by pyrolysis into fuels can contribute to the reduction of greenhouse gases. A series of laboratory tests were performed prior to establishing the best pyrolysis conditions. The paper also deals with research on the gas phase kinetics, which is the main core of a proceeding in the case of utilization process. The obtained test results allowed to determine the mass burning rates that are defined by kinetic constants in the Arrhenius equation.