We were tasked with creating a dryeroven using rocket stoves. Our first prototype was metal and although extremely durable and temperatures never exceeded 450°F we have now insulated our dryer and it also serves as the pyrolyser and temperatures are now around 1200°F:
https://vuthisa.files.wordpress.com/2018/09/img_0095.jpg
The diameter of the kilns have been increased from 1.4 metre to 1.7 metre: