in a 55-gallon TLUD
Tuesday, February 21, 2012
Compost Tea -
Sea Minerals -
Tuesday, February 21 was another beautiful spring day. Warm air, blue sky, few clouds, bright, sharp sunlight. Light, frisky winds moved the air. Lovely day to take pictures of dancing ethereal biomass gas flares.
Local herbalist Joanne Bakeman, Pauline, and her teenage son Joseph, joined us to bust up brush and admire the fireworks. We now have two metal lawn chairs to rest in. We'll need them before we're done turning this entire brush pile into char, plus transform the naked soil into a circular sacred mushroom, herb and flower garden.
VIDEO: Quick View
3 min 24 sec; 7.5 Mbyte, .mov
Brad loaded the barrel with twigs and chopped Johnson grassÑan undesirable invasive. These obnoxious, prolific weeds are often superior biomass converters, and can be harvested to recycle into soil carbon. Brad thinks gamma grass and other prairie grasses can make excellent biochar.
This suits my "weedy, not woody" rule for feedstocks. I'm interested in corn stover, sunflower & artichoke stalks, straw, hay as feedstocks for our burn barrel.
The burn started quick. In five minutes, flames shot out of the chimney cap. In another five minutes, flames formed a wind-blown halo around the cap. At peak, transparent red gas flares flicked up to three feet downwind.
After 45 minutes, the burn quickly ran out of gas, the flare shrank into the chimney. We could easily smother and quench the remaining charcoal fire.
In part, smoke can be attributed to wind changing the draft and air intake into and out of the burn barrel. Strong gusts of wind can suppress flames, downdraft a chimney, and enhance smokiness. But I could see more than the wind was causing the unburned carbon.
Seems we need more air entering the burn barrel, and a lot more air entering the chimney. Most of the gas flames off after it exits the top of the chimney and gets air. Not enough air enters the chimney through our holes and slots to ignite more than a tiny fraction of gases rushing up the 8-inch stovepipe.
Understanding how to control the ignition of that gas flare is crucial to design an efficient heat exchanger. Most of the heat released in a burn is in the gas flare. An insulated TLUD is an efficient, contained, functional primary burner. But a key to new carbon-negative technology is to control secondary combustion in the gas flare.
|THE CHAR CREW
Biochar Burn Home Team
Art, Pauline, Brad, Joseph, Joanne