Thermal Oxidizers for Biochar Off-Gas
Thermal oxidisers that burn the smoke and pyrolysis gas released by biochar kilns and reactors, with heat recovery.
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Kiln smoke burned and turned into useful heat
CRA's thermal oxidisers burn the tar, smoke and pyrolysis gas from biochar kilns and reactors, recover the heat for drying or steam, and include a flare for trips.
Stream
Pyrolysis off-gas
Heat recovery
Dryer or boiler
Trip disposal
Flare included
Kilns
Batch or continuous
What does a thermal oxidiser do at a biochar plant?
Biomass heated with little air breaks down into char and a gas rich in vapour, tar and smoke. The oxidiser burns this gas with air, leaving hot, clean flue gas.
How it works
The flue gas can then heat a feedstock dryer or a boiler, and a flare takes the gas when the oxidiser is offline.
Off-gas flows from the kiln or reactor to the oxidiser.
The oxidiser burns the vapour, tar and smoke with air.
The hot flue gas heats a dryer or a boiler.
The flare burns the off-gas whenever the oxidiser is offline.
Key Benefits
Combustible vapour, tar and smoke in the off-gas are burned before the stack.
Recovered heat can dry feedstock or raise steam.
The oxidiser copes with the changing gas from batch and continuous kilns.
A flare takes the off-gas when the oxidiser trips.
Burner management handles light-off and shutdown.
The CRA Edge
CRA has more than 30 years of experience in gas handling and flare engineering.
Design, R&D and manufacturing are carried out under one roof.
ISO 9001 certified through TÜV NORD, with designs aligned with ASME, API and CE.
Designs are customised to the process needs and the regulations that apply at site.
Applications
Frequently Asked Questions
Why burn biochar off-gas in a thermal oxidiser?
The off-gas carries tar, smoke and combustible vapour. Burning it removes the smoke and odour and gives heat the plant can use.
Can the oxidiser heat the feedstock dryer?
Yes. Hot gas from the oxidiser can supply a dryer directly or through a heat exchanger.
Why does the package include a flare?
The gas still needs a safe outlet when the oxidiser trips, so CRA includes a flare in every thermal oxidiser package.
What data does CRA need to size a biochar off-gas oxidiser?
CRA needs the kiln or reactor type, the feedstock and throughput, the expected gas flow, the planned heat use and the site conditions.
Does tar in the gas cause problems?
Tar can condense in cool ducts. CRA keeps the gas path between the kiln and the oxidiser short and hot.