Effect of the Volume Reduction On the Thermal Conduction Throgh the Pyrolysis of the Biomass

In this report, the visualization of the biomass layer through the pyrolysis has been conducted. The apparent density of the biomass layer was also measured. The setting temperature of the furnace was changed from 250°C to 800°C. The heating rate of the furnace was 400°C /hr. determined From the experimental results, it was found that the volume reduction process was closely connected with the pyrolysis and divided three regions; i) region of dehydration from biomass, ii) region of pyrolysis of cellulose and iii) region of pyrolysis of lignin. It was found that the reduction process of the biomass layer through the pyrolysis could be expressed by the first-order chemical reaction model with the equilibrium. The apparent density depended on the temperature. Especially, the density at T > 350ºC became about 60% of that at room temperature. Furthermore, time course of average temperature in the biomass layer can be reproduced by the numerical simulation of the thermal conduction through the pyrolysis, which is included in the change of the apparent density and the change of the biomass surface by the volume reduction.