September 14, 2025
Thank you everyone!
With your help I was able to get a wood chipper and shred the pile of biomass resulting from clearing the greenhouse site. Species present include french broom, cotoneaster, pokeweed, tamarisk, redwood, date palm, wild oats, ripgut brome and red pepper tree.
This produced a 12'X4'X16" deep pile of mulch, or 64 cubic feet. At a density of 4.8oz/l this is a mass of 544lbs, or 247kg.
Roughly half of this consists of dry grasses and branches, the other half is fresh woody vegetation, so around 1/4 of this mass is water, giving 185kg of dry biomass. At average proportions, this contains 93kg of carbon.
The best way to permanently fix as high a proportion of this carbon as possible is to convert it to its elemental form through the action of heat in the absence of oxygen, this will convert all substances other than carbon into gases that will boil from the wood chips and in their burning provide heat to sustain the process.
This is called pyrolysis, or dry distillation, and creates biochar as an output. Biochar is an excellent soil amendment, regulating pH, retaining nutrients, and improving soil structure. As elemental carbon, it is mostly inert from a biological and chemical perspective, and so the carbon it contains is unlikely to return to the atmosphere in the next 1000 years at least.
To make char, heat has to be applied in an oxygen deprived environment. The method usually used is the Top Lit Updraft Gasifier, consisting of 2 nested metal containers and a stove pipe. The drawbacks of this method are that it is a batch process and does not scale smoothly, while also sacrificing a portion of the biomass as fuel. I am interested in testing a different method, a conical kiln based on Japanese charcoal manufacturing methods.
Reported efficicency ranges between 25 and 50%. Another $400 will enable me to get a conical kiln, an essential piece of equipment for the nonprofit which will be used heavily, and will permanently remove between 24 and 47kg of carbon from the atmosphere while producing a soil amendment to grow more super aspens! All efficiency data will be recorded.
This also represents a small scale test of the integrated coppicing and char production system that will be deployed on planting sites.
September 11, 2025
Greenhouse site measured and marked out, mown and weed-eaten, and resultant biomass raked and heaped. I'm keeping the heaps moist to encourage decay and produce compost for propagation, need to get high temps in the center of the pile to help kill any stray french broom seeds.
Site is cleared of broom and pokeweed; there were some real big roots! Next is leveling and I will need pressure treated 4X4 to frame plus drain rock for the floor.
With the site prepared, I also propagated 200 cuttings from my indoor mothers (thanks for your help Elysha!!), and installed a light in my rooting window to extend the photoperiod to 16/8 to enable rooting to continue in winter.
Got the first bulb for my greenhouse photoperiod extension lighting. Need 3 more.
In process of acquiring an electric wood chipper to reduce the particle size of my biomass pile. I'm avoiding using city compost as far as possible to retain carbon within the system.
