Throughout the thirteen years or so that i have been building this blog, one of my primary objectives was to fully realize the future of global agriculture. My instrumentality is the natural community optimizing a swath of land. Economically the natural community numbers around 150 individuals put in combination with three other communitues to occupy a crossroads. This will easily work with a square mile of land and additional wastelands as well.
Central to our future will be the steady production of biochar to act as a nutriant sequestering agent. The soil does well with a five percent biochar content. That is sufficent.
Biochar is made from plant wastes in particular. Particularly those lacking sufficent nutrients to break down fully into the soil. Think straw and corn stover in particular along with well chipped wood fiber. you do not want to end up with large chunks in the process. I would design around all likely agro waste and then top of the supply with wood chips pulled bin from properly grooming woodlots.
All this plant waste needs to be stored in a drying shed as well leading up to the cold months.
I do think that this dried waste can be processed during the winter to produce the biochar and hot water as well to heat the housing used by the four communities.
The reason i think so is that the roasting kiln needs to operate continously through a two chamber process. The first chamber brings the temperature up to 600 plus degrees, suffiicent to reduce the material to elemental carbon. It can also act as a prewarmer for the hot water system to keep the chamber from exceeding 600 degrees and to bring the temperature of hte spent char down.
The second chamber takes the off gasses, adds oxygen and some propane if needed to bring the burn temperature up to almost 2000 degrees. This oxydizes the gas flow and reduces it all to CO2. It will not need a lot either.
We now have a stack gas at a temperature of 2000 degrees which can be used to finish the water heating process for the community.
Something like this can be readily operated all winter to produce substancial biochar on an ongoing basis. It would be cooled directly in water, screened and then blended with screened soil in order to made an easily worked with final product.
All this envisages a large V shaped drying shed and small kiln plant able to process even a ton per hour. A large capacity hot water storage tank is also envisaged.
It should be possible to internalize the community's heating needs with a system like this. That is going to be a problem as we transition to a battery based energy system.