biochar

1. Simple production and post-
pyrolysis processes.
By: Josiah Hunt
Owner of Landscape Ecology and
Hawaii Biochar Products LLC.

2. Please note
• I view this method of producing biochar only as
an alternative to more costly options.
• Any attempts to harness heat or gaseous energy
are essentially forfeited.
• It is not the safest option available.
• It can be a way to produce meaningful quantities
of high quality biochar if done correctly.
• It can provide a simple and beneficial alternative
to burning waste organic material to ash, as is
currently done by many as a means of disposing
of biomass.

3. Biochar with a shovel and dirt

8. Wood-gas flames have subsided, soon to be covered

10. Covered with 4-6” of dirt and monitored for 5 days

11. Why “bake” the biochar?
• When the wood has burned to embers, it’s
then covered with dirt to “bake” for five days.
• I have found that the quality of the char as a
soil amendment can increase during this time.
• After baking, the biochar comes out softer
and cleaner (less tars and resins).
• Depending on how the soil breathes, the
temperatures can remain between 400-800oF
throughout the baking period.

12. When dirt is removed char is still hot, can re-ignite easily and
should be doused with water and removed from the pit.

13. 0.10%
1.00%
10.00%
100 120 140 160 180 200 220 240 260 280 300
Adsorption
of
R134a
-
wt
%
Temperature Celsius
Minimum CC#10
Maximum CC#14
Lehmann Oak 550C
Lehmann Pine 550C
Josiah Hunt biochar
Josiah Hunt cattle bone char
Range of Commercial
Lump charcoals for cooking
Adsorption analysis courtesy of Hugh Mclaughlin

14. Grinding
*Grinder designed and built by Robert “Bob” Ely P.E.

17. ½” minus

18. One size does not fit all
• While a smaller particle size may give you
more available surface area, larger particles
may hold water and nutrients longer.
• We have found that for our soil type and
climate the ½” minus biochar works well for
general purposes.
• Other blends have been made for special
orders such as a ½” to ¾” clean for orchids and
a ¼” minus for fertilizer blends.

19. Enhancing the product
Biochar inoculated with beneficial microorganisms

20. Composting with biochar
• The hot, moist, nutrient rich environment of compost
can enhance qualities of biochar important to plant
growth such as:
- Water retention
(hydrophobic tars and resins can be quickly decayed by microbial activity)
- Available nutrients
- pH
- CEC (by heat, microbial activity, and humic substances)
- Beneficial Microorganisms

23. Moving Forward
working on more efficient biochar production methods
Towards fuel recovery, greater efficiency
And the ability to handle municipal green
waste. Towards making a positive impact on
Hawaii and the world. Towards an
ecologically and economically sustainable
biochar system.

24. www.landscapeecology-hawaii.com