Ultra-High Temperature Flash Pyrolysis of Biomass (1300 - 1600 C)

Biomass gasification is a promising low carbon technology for the thermochemical conversion of solid, low-value feedstock into electricity and usable fuel. The thermal decomposition, or pyrolysis, of biomass is an initial step in gasification. Understanding pyrolysis may lend insight into optimizing gasification processes. An entrained flow reactor was used to characterize the pyrolysis of two biomass feedstocks, microalgae and rice hulls, at ultra-high temperatures between 1300 and 1600 °C. A characteristic time analysis was conducted to assess the relative rates of the various involved phenomena during pyrolysis including heat transfer, mass transfer, and chemical reaction time. Additionally, product gases were analyzed and compared to thermodynamic equilibrium predictions in order to assess the effect of increasing temperature on driving the involved reactions towards equilibrium which favors the production of valuable synthesis gas. Surface area and porosimetry of the resulting solid products were also analyzed to assess the effects of pyrolysis temperature on the characteristics of the pyrolysis product char.