David Derbowka is one of my favorite kinds of charistas; creative, collaborative and cares about what matters most – a better climate future. David is an environmental engineer heading up his own company, PRSI, in a faraway place in Western Canada between Calgary and Vancouver. One of his areas of focus is phytoremediation of landfill leachate using fast growing poplar trees to soak up contaminants. Carbonizing these trees helps to reduce their bulk but some contaminants (e.g. metals) may remain ensconced within the carbon lattice.
Wanting to find a non-soil use for his biochar, David has been experimenting with using it in different materials such as bricks and drywall. The samples he sent me many moons ago have traveled with me to all sorts of places including most recently to COP24 in Katowice, Poland. I’ve told his brick story many times and plan to tell it many more times to come. But now folks can hear about biochar bricks directly from David himself in this new youtube video.
Many folks enquire about recipes for using biochar in various building materials, wanting to save time and money leveraging what others have gleaned. For better or worse, many in the biochar world (and beyond!) are rather tight lipped when it comes to sharing this type of information, preferring to adhere to the capitalistic paradigm of prioritizing profits from patents. (This approach is a big part of what got us into our current carbon calamity.) David’s world view is the antithesis of that mode of thinking. As but one example, he recently shared his experiences openly and honestly with a group in South Africa that was looking to boost rural employment through green building materials.
These global, often times altruistic, collaborations are exciting to be a part of. They are what is needed to spread hope, knowledge and solutions far and wide. In this respect, I see David not only as a fellow pyrogenic lamplighter, but as one of biochar’s emerging ‘thousand points of light’ – an expression made popular by former President George H.W. Bush. It was a modernized version of former President Kennedy’s “ask not what your country can do for you, but what you can do for your country”, which was a reinterpretation of the Three Muskateer’s (and the nation of Switzerland’s) motto: ‘all for one and one for all”. We need a XXI century version of this rallying cry (or maybe these days a meme would be more appropo!) that promotes a balance between taking and giving, between carbon spending and carbon banking, and perhaps hardest of all between profiting and planetary health.
1 part Portland Cement
1 part water
3 parts biochar: note biochar should be soaked in water prior to mixing at a rate of 4 cups water to ½ cubic foot of biochar to reduce dust; particle size should be 1/8” or less.
- Mix water and Portland Cement together first
- Fold in three parts biochar. A 1/2 inch electric drill makes this easier, but could be done with muscle power. If you find the mix too dry, add water, but very little, because it gets over wetted easily. Too much water can slow curing and reduce compression strength.
- Pour biochar concrete mix into well oiled molds quickly after thorough mixing, returning a bit later to make perfect smooth finish.
- Once the product has hardened sufficiently (within 24 hours) cover with burlap soaked in water to keep it wet if possible.
- Wait 48 hours before emptying the molds or forms.
- After removal, immerse bricks in water for two days. During all moistening procedure, the char sucks up the water, and lets the portland finish curing
- Remove bricks and let them dry for ~ 27 days before using them.