544 / 2018-09-25 20:29:50

Kinetic analysis and thermal parameters properties evolution of Eucalyptus pyrolysis

生物质多联产 > 生物质多联产

In recent years, with the growth of population and shortage of fossil energy, the environmental pollution problem becomes more severe. Biomass, especially eucalyptus planted in south China, is a renewable and promising source of energy. The objectives of this research were to study the pyrolysis kinetic of eucalyptus and thermo-physical properties of bio-char, including bulk density, specific heat and heat conductivity coefficient. TG-DSC was used for pyrolysis kinetic analysis with heating rate of 10, 20, and 30°C, temperatures from 25 °C to 900°C, and N2 flowrate of 30mL/min. Pyrolysis experiment was carried out in the temperature range of 150-850°C. Results showed that eucalyptus pyrolysis, with four stages, includes drying, preheating, fast pyrolysis, and carbonization. The activation energy and frequency factor of each stage were obtained by Ozawa-Flynn-Wall method and Friedman methods. Solid yield was decreased while the lower heating values of bio-char were increased gradually with the increase of temperature. Bulk density was decreased first and then increased while the volume energy density was increased in the whole experimental temperature range. The specific heat and heat conductivity coefficient were closely related to the moisture content and pores structure in bio-char. With the increase of treated temperature, the specific heat of sample presented a U-shaped tendency which was decreased firstly and then increased significantly. The heat conductivity coefficient was increased according to exponential growth after slight decrease.