I approved this comment about 1 day after I asked the
question. It always amazes me how willing to help most people are. So for Green Mountain Coffee folks I hope this gives you more to work with on your Project to Biochar coffee husks in Australia.
Comment from Paul Olivier Email him here
It is easy to gasify coffee bean husks in a top-lit updraft gasifier. But a small fan is needed to force air through the husks. I use a small 40 x 40 mm fan, and the speed of the fan is controlled by a speed regulator. The amount of power consumed by this fan in the gasification of coffee bean husks is generally less than one watt.
Virtually no smoke is created during the gasification of coffee bean husks.
Here are two pictures of coffee bean husk being gasified:
I did a similar experiment with much drier coffee husks, and I got a much bluer flame that what you see in these two pictures.
Of course I get a much better result gasifying rice hulls:
Here are some of the latest designs of my 150 mm gasifier:
All of these gasifiers are fabricated out of stainless steel so that they can be used over many years.
My 100 gasifier sells for about $30 US.
The 150 gasifier sell for about $50 US.
This is a totally non-profit effort.
I also design larger gasifiers of a 100 kW capacity.
Here equipment price drop to less than $5.00/kW.
For the larger waste management concept that I am promoting in developing countries, see:
This is a great resource and I would like to thank the author for his rapid responce to a biochar question.
Charmaster Dolph Cooke