There is an up and coming natural building and gardening technique that can actually sequester carbon in buildings, stoves, soil, etc for thousands of years, and can also capture carbon from the air and trap it, as well. It can also clean the air in your house and rid you of air pollutants like mold spores. Utilizing this technique properly, we can actually reduce the amount of carbon in the atmosphere, and improve the air quality of our homes. This technique is called Carbon Sequestration.
I’m really a fan of this idea for multiple reasons, but the obvious one being to build as many buildings as possible out of this method so we can actually attempt to reverse climate change.
Our politicians have made it abundantly clear that they aren’t taking this whole thing seriously enough, so now it’s up to we the people!
Everyone is familiar with fire! It burns things and leaves nothing but ash left. But that’s because your typical fire utilizes oxygen as a major fuel source. If one were to burn carbon based organic matter, and keep the oxygen out of the whole mix, your matter wouldn’t turn to ash, but would remain chunks of pure carbon. This is what we, in the natural building world, call Bio-Char. There are many methods of making bio-char, most of which use containers inside containers to keep oxygen away from whatever they are burning.
So… What is “Whatever they are burning?”
Well, essentially, any carbon based matter would work, but some things work more efficiently than others. Wood, for example, leaves a good bit of bio-char to use as it is mostly carbon. But even woods are different. One of the best woods to use is bamboo! (I think we’re all familiar with the versatility of bamboo, but it’s probably even more versatile than you think!)
The porousness of the bamboo makes really porous bio-char, and we’re talking holy crap porous! (pores inside of pores, inside of pores, inside of pores! Essentially micro-bacteria take up residence in all the nooks and crannies of the bio-char, and clean the air. The more porous the material, the more bacteria it can hold and the more efficient the cleaning can be!
In building, biochar is mixed with the finishing plaster coatings which are usually made of a mixture of sand and clay, but some people like to add other things to the mix as well. This is used to basically smooth out the interior and exterior walls. Here at the Eco-villiage Training Center, we use sand, clay, re-hydrated lime, and the bio-char. Lime is essentially Calcium Hydroxide. (You can think of it as limestone that has had some of it’s stone properties chemically taken away through a heating process.) Over time the lime used will draw in carbon (Hey, see how that keeps coming up!) and bond with the carbon which turns the re-hydrated lime back into limeSTONE, continually hardening the plaster over time. So, yeah… you’re right with that thought! Using this plaster strengthens your home over time, rather than deteriorating! Using the bio-char in the plaster also allows for the interior walls to clean the house air, and the exterior walls to clean the outside air! WIN-WIN BABY!!!
Bio-char is also utilized in soil for gardening, etc. In this method, it’s used to improve the health of the soil in order to grow healthier and better yielding crops. Again, bacteria and minerals get trapped up in the bio-char (sequestered carbon) but this time, they feed the plant root systems. it takes several years for the bacteria to build up and start being beneficial to the soil, but there are ways of speeding that up! One way is to soak the bio-char in urine for a while before adding it to your soil. Urine is full of nitrogen, and the two major things plants need in their soil is nitrogen and carbon. This way, you are giving them both! Another way is to add it to your compost and let the nice organics of the compost get trapped in your bio-char. The final way is to soak it in urine and then add it to compost!
You can see why this technique is gaining extreme popularity in natural building circles and with permaculturists.
The method we use to create the bio-char is, actually, simpler than most methods. We dig a hole in the ground, and set bamboo on fire!
“Um… Josh… I’m not quite sure you understand this whole fire thing. Didn’t you say you had to keep air OUT of the burn? This sounds like just a fire on the ground.”
Nope, this is a fire IN the ground. We shape the hole to resemble a WOK. this creates a pocket which is deficient of oxygen at the bottom of the Wok. once you pile enough bamboo on top, you then make a ceiling of bamboo over the top to help keep out more oxygen. This method is VERY effective, and faster than other methods. The last burn we did produced enough Bio-Char to fill up roughly 3, 50 gallon barrels in roughly 45 mins. (This is merely an eye-balled guesstimate to the volume was produced.) We then grind up the large chunks of bio-char into smaller more powdery pieces, and mix it with either compost, or plaster.
Viola! And there you have it!
Here are some pictures from some of our process: