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Not completely. If the wood is from renewable sources, the carbon usage is low, because it gets recaptured when they grow the next batch. Net carbon usage is fr

by ajb 2y ago

Not completely. If the wood is from renewable sources, the carbon usage is low, because it gets recaptured when they grow the next batch. Net carbon usage is from transport and logging. As such it's much better than fossil fuels. It does contribute to air pollution, but that's more of a problem in a city, where it's diluted over a smaller area. I did once look into whether it would be possible to run a carbon negative BBQ by doing wood pyrolysis of renewable wood and ending up with black carbon to bury. It does seem possible, but still has the air quality issue. And there's a risk that you'd emit some methane (if you fail to burn it), which would be bad. Also, I wasn't sure how to figure out whether it would emit more CO than a normal BBQ. In theory that would be the best case for carbon though.

SideburnsOfDoom 2y ago
The issue with pizza ovens specifically is that they reach operating temperatures (450-500C / 840-930F) where black carbon does not accumulate, it oxidises away into the air. I see this happen every time I use my pizza oven and leave some flour behind in it.
- ajb 2y ago
  Yeah I was going off at a tangent from pizza ovens. Pyrolysis happens when you heat wood in a chamber with low ventilation (low oxygen) , which causes flammable gases (methane, CO etc) to be emitted, leaving black carbon. The flammable gases are then burned separately, to sustain the process and also to heat whatever you want. Methane burns at hot enough temperatures to power a pizza oven; so in theory you could construct one powered by pyrolysis, but it isn't going to happen in an unmodified one. A normal one should be constructed to ventilate the wood well, to avoid emitting too much CO. There is a video on youtube of some guy pyrolizing some wood by putting a metal box with it in in his oven - it's not rocket science. But I live in a city, so in the end it didn't seem like a good idea to experiment with it.
xbmcuser 2y ago
well your methane calculation might be out a bit https://news.ycombinator.com/item?id=41075095 https://news.ycombinator.com/item?id=41075095 https://www.bloomberg.com/news/articles/2024-07-24/tree-bark-removes-climate-warming-methane-from-atmosphere-study-finds https://www.bloomberg.com/news/articles/2024-07-24/tree-bark...
- ajb 2y ago
  Oh, that's good news.

by ajb 2y ago

SideburnsOfDoom 2y ago

The issue with pizza ovens specifically is that they reach operating temperatures (450-500C / 840-930F) where black carbon does not accumulate, it oxidises away into the air. I see this happen every time I use my pizza oven and leave some flour behind in it.

ajb 2y ago
Yeah I was going off at a tangent from pizza ovens. Pyrolysis happens when you heat wood in a chamber with low ventilation (low oxygen) , which causes flammable gases (methane, CO etc) to be emitted, leaving black carbon. The flammable gases are then burned separately, to sustain the process and also to heat whatever you want. Methane burns at hot enough temperatures to power a pizza oven; so in theory you could construct one powered by pyrolysis, but it isn't going to happen in an unmodified one. A normal one should be constructed to ventilate the wood well, to avoid emitting too much CO. There is a video on youtube of some guy pyrolizing some wood by putting a metal box with it in in his oven - it's not rocket science. But I live in a city, so in the end it didn't seem like a good idea to experiment with it.

xbmcuser 2y ago

well your methane calculation might be out a bit https://news.ycombinator.com/item?id=41075095 https://news.ycombinator.com/item?id=41075095 https://www.bloomberg.com/news/articles/2024-07-24/tree-bark-removes-climate-warming-methane-from-atmosphere-study-finds https://www.bloomberg.com/news/articles/2024-07-24/tree-bark...

ajb 2y ago
Oh, that's good news.