TANASE DOBRE, OANA CRISTINA PARVULESCU, INMACULADA RODRIGUEZ RAMOS, LAURENTIU CEATRA, MARTA STROESCU, ANICUTA STOICA, RADU MIREA GLOBAL REACTION KINETICS AND ENTHALPY IN SLOW PYROLYSIS OF VEGETAL MATERIALS
Fixed bed pyrolysis of corn grains impregnated or not with a nickel nitrate solution was performed under carbon dioxide atmosphere, obtaining permanent gases, a pyrolytic oil and a solid residue (char). The distribution of pyrolysis products was dependent on variations in heat flux, carbon dioxide superficial velocity, grain size and impregnation degree. Correlations between these factors and process dependent variables, i.e. char mass, oil mass, operation time, material bed centre temperature and column wall temperature, were established using a 23 factorial plan. A one-stage global reaction kinetic model was selected to describe the process dynamics. An unsteady state model based on heat and mass transfer from solid particles to gaseous phase was adopted to estimate the global reaction enthalpy. The results obtained may provide useful data for the design, scaling-up, optimization and operation of fixed bed pyrolysis reactors.