I have been thinking about how to make a carbon negative BBQ.
The idea would be, use sustainably grown wood (so you start nearly carbon neutral) and pyrolyse some of it, and bury the resulting carbon.
There are some fairly simple examples of home pyrolysis of wood on youtube, using two nested steel barrels. The wood inside the inner barrel is pyrolised, initially using heat from fuel in the outer barrel, and once it has got started, by combustion of the gases given off by the heated wood.
The idea would be to incorporate this into a barbeque that anyone could do. IE, set it up, light it, cook over it, and then bury the resulting charcoal.
It sounds fairly easy to experiment with, HOWEVER I am concerned about whether larger volumes of carbon monoxide would be emitted making such a setup less safe than a normal barbeque. Reading around, a normal barbeque emits around 8% of its gas output as CO, which is why you need to be very careful not to use one in a confined space. So fairly simple precautions can deal with some CO. But the point of pyrolysis is to heat wood in a low oxygen environment, so I'm concerned that a more CO-rich, and hence more dangerous, gas mixture might be emitted.
Most home-pyrolysis setups seem to involve leaving the setup to do its thing, whereas you obviously need to stand over a barbeque with the burgers etc so it needs to be sufficiently safe.
Is there a way to do a back-of-envelope calculation of the CO emissions of such a setup, and whether the concentrations would reach dangerous levels? Or a safe way to measure it?
