2020 Volume 60 Issue 9 Pages 2107-2111
A rapid carbonization process of biomass to indirectly utilize exhaust heat by using heat storage materials (HSM) is proposed. In this process, carbonization proceeds by the heat transferred from HSM balls and the simultaneous pulverization through collisions with balls. This paper deals with the synergistic effect of the pulverization of biomass on its carbonization behavior. Biomass samples were charged together with stainless balls into an electrically heated rotary kiln-type reactor. Carbonization and pulverization experiments were carried out through both simultaneous and separated processes. The formed chars were characterized through evaluation of carbon crystallinity and observation of morphology.
The linear relationship between yields of char and carbon crystallinity was confirmed. The proposed process promoted both carbonization reaction and pulverization phenomenon. Carbon crystallinity increased with increase of carbonization time and became to be lower than that separated process. Biomass samples started to deform after 1 min in the simultaneous process due to melting of biomass surface. Deformation of char with higher stress resulted in higher pulverizing ratio and also it seemed to accelerate the pyrolysis/volatilization of organic compounds such as lignin.
