Frequently Asked Questions

Charcoal is a high carbon, low density black residue produced by heating plant or animal materials in a restricted oxygen environment.  This is what's made in the solar-powered kilns used by the Carbon Trap Project Community.  Carbon trapped in buried charcoal is stable for millions of years. 

Biochar is sometimes used synonymously with charcoal.

Biochar is charcoal used for biological purposes like in soil, aquatic and digestive systems. Biochar is a relatively new term coined in the late 20th century.  Carbon trapped in soil biochar is stable for thousands of years.  

As a relatively new term, biochar is often used synonymously with charcoal in carbon sequestration projects.

Yes.  Unless you burn it.  Please don't.

Charcoal is made from heating biomass in a restricted oxygen environment and coal is made from heating biomass in a restricted oxygen environment under great pressure making it more dense than charcoal.  Both have similar chemical structures being made up of carbon polymers of six-member hexagonal rings.  Neither are food for lifeforms.  Both are indigestible, i.e. they don't rot.

Like coal, buried charcoal is stable for millions of years.  Even when exposed to the assaults by the voracious aerobic life in soils one carbon 14 labeling study demonstrated biochar is stable for thousands of years, which isn't bad.  Still burying is best.

Send it to the landfill where it'll be permanently buried.  The trucks are going there anyway, so there's no increase in carbon footprint.

Yes.  Nature scrubs carbon from the air using renewable solar energy (photosynthesis).

Then the CTP community permanently traps a lot of this carbon in the charcoal they produce from food and yard wastes for landfill burial.  An all net negative process.

There is a carbon footprint from equipment manufacturing and shipping.  But since this equipment is repeatedly used the project is strongly net carbon negative.

There may be some carbon footprint from cleaning the equipment, but this is small and doesn't change the net carbon negativity of the CTP.

That depends on what your goals are.  If you need fertilizer for your garden you should compost.  If you're more concerned about climate change and want to reduce atmospheric carbon you should char.  Composting releases more carbon back into the air than does charring.  Charring releases less and traps more carbon than composting.

Take coffee grounds for example.  Dry coffee grounds are about 49% carbon according to our chemical analysis.  So 10 pounds of dry coffee grounds contains about 4.9 pounds of carbon.  Composting this would lead to the release of 95% or 4.6 pounds of carbon back into the air, retaining only 3.9 ounces.  But you'll have some great natural fertilizer.

Alternatively, charring the 10 pounds of dry coffee ground reduces the released carbon by more than half, releasing only 2.3 lbs.  Further, the charcoal product permanently traps 54% of the carbon or about 2.6 pounds; almost 11-fold more carbon permanently trapped than composting.

Another difference is speed.  Composting is a slow process requiring frequent stirring and tending for weeks.  Charring is complete in a few hours.  Then just send the charcoal to the landfill and you're done.

Charring releases about half of the biomass carbon back into the air, compared to natural decay which releases nearly all of it.  Charring is fast causing a rapid off gassing that is seen as smoke.  Natural decay off gases slowly over weeks, so you don't see any smoke.