Kosfeld Fenna Thesis - Flipbook - Page 47
Process for making Biochar with Barrel Retort Kiln
Retort kiln:
biomass/waste is externally heated and through gas flow
heat remains in kiln longer
economically accessible
can be made of scrap metal
good for small-scale production and local use
1 Preparation:
Select a metal barrel (typically 55-gallon) for the kiln.
Gather the biomass feedstock (e.g., wood chips, agricultural residues, or other organic materials).
Ensure the feedstock is dry to improve ef昀椀ciency and quality of the biochar
2
Loading:
Fill the barrel with the prepared
biomass, ensuring it is loosely
packed to allow air昀氀ow.
If using a retort, place it in the
center and 昀椀ll it with biomass
as well.
5 Cooling:
Once pyrolysis is complete, seal
the barrel or cover it with a metal
lid to cut off oxygen and allow
the biochar to cool slowly.
Avoid exposing the hot biochar
to air immediately to prevent it
from combusting.
no C02 produced, left with stabile
carbon and hydrogen
3 Ignition:
feedstock will be
charcoalised / carbonised
Light a 昀椀re at the bottom
of the barrel using kindling
or other small combustible
materials.
Allow the 昀椀re to burn and
heat the biomass. As the
temperature rises, pyrolysis
begins, and volatile gases are
released.
4 Pyrolysis:
Control the air昀氀ow to ensure the process remains oxygen-limited, preventing complete combustion.
Maintain the pyrolysis process until the biomass is converted to char, which may take several hours
depending on the volume and type of biomass. Temperature between 300-600 ºC
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