Pyrolysis profiles of a traditional circular kiln in Austria and a drum kiln in Namibia

Charcoal production is a handicraft of oldest tradition. Various types have been developed. One of the most popular in Europe was the circular kiln with vertically piled logs. Besides traditional techniques new developments arose during the last decades like drum kilns in Namibia. Infrared spectroscopy was applied to assess pyrolysis temperatures using an already existing prediction model. A comparison of the two very different kiln techniques revealed systematic differences in the pyrolysis process and profile, but also comparable temperature ranges from 400 to 700 degrees C. These results correspond to literature values for circular kilns and rectangular kilns with horizontally piled logs. Temperature measurements by means of thermocouples supported infrared spectroscopic results.