[Terrapreta] biochar from stoker boiler

[Alex and Christine English]

Ron,
This was a preliminay test to see how chopped switchgrass behaved in the feed 
system. It was chopped in a Supreme 600 Feed Processor. It isn't likely the right tool 
but it did, with sufficient time, reduce the loggest peices to <3" and the bulk of it 
much finer still. This material then had a bulk density of 8 lb/ft3, only a little less than 
the 9.3 of the bales and 11 of dry chips.

It flowed easily into the augers that make up the feed system to the boiler.

I hope to go ahead this summer with modifications to the ash system to facilitate
the capture and quench of char from any of the fuels we use.

More than the char we are interested in the degree of ash fouling and its corrosive 
potential in the tubes of the boiler. We are trying to develop test proceedures which
predict the suitability of ag fuels and burning methods, with an eye to the long term 
durability of the boiler. 

There is a lot more to be done before we try a steady state run of a week or more.
Most likely in the fall.

This chopped fuel behaves on the grate a bit like sawdust. I liken it, oddly, to a glacier 
with crevaces where the air blast through surrounded by air starved regions, with the 
occasional burg calving off. It is no one"s ideal fuel (porrous) for stable combustion.
It is however fine for testing our other concerns without bothering with densification.

Regards,

Alex