Investigation of devolatilization characteristics of pulverized corn stalk at flash heating rate

The pyrolysis of pulverized corn stalk has been studied in a laminar entrained flow furnace with the aim of determining the devolatilization characteristics of biomass particles at flash heating rate. Variables investigated were reaction temperature between 800 K and 950 K and residence time between 0 .108 s and 0.224 s. Pulverized corn stalk particle size, ranging between 0.117 and 0.173 mm, was not controlled as a variable in this study. Plasma jet flow was used as the heating source to achieve a stable and controllable high temperature gas flow for the flash pyrolysis of biomass in the furnace. Argon was used as the working gas with flow rate ranging from 1.5 to 2.5 m³/h. The solid product of pyrolysis (char) collected by a water-cooled collecting tube (quench unit) and a cyclone collector was used for determining the volatilized fraction of the biomass being pyrolyzed via the ash content in the solid as a tracer. Based on the experimental results, an Arrhenius form first order reaction kinetic model of biomass pyrolysis in the furnace was introduced and relevant kinetic parameters of corn stalk pyrolysis were determined. The results show that the devolatilization characteristics of fast pyrolysis differs from that of slow pyrolysis. The studies on biomass devolatilization characteristics at flash heating rates are very important in the investigations of biomass pyrolysis liquefaction mechanism.