Anyone make biochar?

[Prof]

Anyone ever make biochar/bone meal in the stove. I make a lot of stock from various bones and often throw the bones in a hot fire when done. They burn up nicely and add a bit of substance that makes for better traction in the driveway. I'm considering separating the bones and smashing them to go in the garden. Anyone have any experience with this?

 

[begreen]

Yes, I've toyed around with it. It's easy to do with whatever you've got that contains carbon. I've used nut shells. I've also done larger scaled biochar production with friends. All of this is to add to compost or garden soil.

In the stove the easiest thing to do is take a couple standard cans (like diced tomatoes or beans) and crimp the end of one so that it fits into the other to make a retort. You can poke some holes into a can if desired but not necessary. Fill the uncrimped can with bones, twigs, nut shells, etc. then cram in the other can. Place on a bed of coals and watch. It will flame for awhile as the stuff outgases. Once it stops, in about 15-30 minutes it's done. Remove from the coals then cool. When cool you can transfer the char to a container to collect a batch for later smashing. A friend uses a blender he picked up at the thrift store to chop his char into flakes for the garden.