Biochar Wok Stove
I try to make little projects every few months that relate to Green Wizardy subjects. I live in an apartment, so it's difficult at the moment to get very involved the the food growing aspects of the resilience toolkit (though not impossible, I could find a community garden of some sort) and I don't have a house that I can tinker with or make improvements on.
So my idea is to take on small projects that at least get me working with various principles involved in Green Wizardry: heat, food preservation, alternative cooking methods, recycling materials, space heating, etc. and to try to consider these things from a systems points of view, thinking about their inputs and impacts, and how they inter-connect with other things. My idea is to plant as many seeds in my head as I can, and maybe they'll be a grow into something larger when the circumstances call for it.
Anyways, the project that I'm working on now is a 'biochar wok stove', basically a way to sit a wok pan over top of a burner that is producing biochar as end product (instead of wood ash.) I plan to write up a blog post about it, related to some ideas I had about cooking on woks, etc. For now, I posted a short video of the project to youtube:
For anyone who is not familiar with biochar, it is pretty much similar to charcoal, it is created by heating organic matter (very often wood) in a low oxygen environment, basically baking it so that volatile gases are emitted from the wood, leaving behind char, that is largely composed of carbon. That low-oxygen heating process is called pyrolysis.
If biochar is any different than charcoal, it is because it is often made at hotter temperatures than the traditional lower-temperature smoldering processes for used for making charcoal, and because it is often made to be added into soils, while charcoal is usually made to burn. (It also differentiates it from charcoal "briquettes" which have a lot of additives in them to make them burn better, etc.)
"Labile" carbon is the kind of carbon that is easily broken down by microbes (e.g. corn stalks, fallen trees, dead animals) and returns to the atmosphere mainly as carbon dioxide, to be pulled down to the land again eventually by plant phytosynthesis in the carbon cycle. Biochar, however, is "recalcitrant" carbon, which is very resistant to decay, they say for most cases, thousands of years, if not more.
Biochar is a very porous material, with many cavities within it, which materials adhere to very easily (which is why Brita filters along with many water treatment systems and beverage companies use charcoal to filter water). It is argued that biochar, when it is added, crushed, into a compost pile, or inoculated with compost tea, or urine, or mixed into humanure systems, can provide habitat for beneficial soil microbes and be a storehouse for nutrients for plants to draw from.
Biochar also holds onto a lot of water, so some think it could be a method to improve drought resistance from soils. Ironically, it can apparently help with drainage when it is incorporated into heavy clay soils.
There is some controversy about how much of a miracle cure biochar is for degraded soils. I've often heard that it is pretty helpful in degraded tropical soils, but less so in the temperate regions of North America. But I think a lot of studies haven't taken into account the types of nutrients and microorganisms that are being soaked into the char before it is added to soils, I'm thinking that could make a big difference, but I'm no expert in gardening and agriculture so I really couldn't say
One thing that is getting me interested is seeing applications for biochar in a lot of building products, allowing us to sequester carbon and to turn organic waste materials into useful products, so that new crops can draw down some of the carbon we have put in our atmosphere by burning fossil fuels, among other things.
Anyways, I'm thinking if we can use the heat created through making biochar, so much the better, so that's the spirit behind the biochar wok stove. It's actually not a bad choice for an outdoor cook stove, they are pretty much smokeless, they create a lot less soot than other kinds. And they give a slow steady long lasting heat, it is basically cooking over wood gas, a similar sort of flame to natural gas.
Anyways, let me know what you think! Thx.