The second stage is just taking the CO and H2 (syngas) released by the #pyrolysis process and burn them to heat your bricks.
The actual gas released is probably much more oily, dusty and CO2 rich than it would ideally be. A lot of contents will be less pyrolysed and more distilled off the wood and partially burnt -_-
Im not sure, if that has enough energy to run the brick oven.
It may be possible to run that in as additional feed into the oven and keep the normal wood thing.
4/x