Title : Opportunities in auto-thermal carbonisation techniques for loose biomass- A concept review of recent experimental work
Abstract:
Reactor configuration strongly influences the efficiency, energy performance, and stability of sawdust carbonization systems. Recent work by Charis and Patel (2025) demonstrated that an open mound intra-carbonization reactor can sustain conversion using external fuel at just below 10% of the total mass of raw sawdust, through strategic heat retention and controlled oxidation. Further experiments on alternative configurations based on a cylindrical reactor and cone-base reactor evaluated a broad suite of eight geometrically distinct systems, revealing the influence of particle-size stratification, airflow pathways, and combustion chamber positioning on temperature distribution and reaction-front behavior. Compounded with other auto-thermal conversions such as on flash carbonization and kon-tiki, these studies provide complementary insights into intra-bed heat transfer, permeability-driven reaction propagation, and the trade-offs between insulation and open-draft designs. Key findings include the superior heat uniformity of the intra-carbonisation open mound reactor, the strong adaptability and ~90% conversion efficiencies observed in cone reactor configurations, and the critical role of stratified packing in improving thermal penetration. This paper condenses findings throughout such experimental work, comparing it to similar work on kon-tiki reactors to identify critical parameters to be considered when setting up a reactor for spontaneous, auto-thermal pyrolysis of loose biomass.
