[Gasification] Drying

[doug.williams]

Hi Adam, and Colleagues,

The short answer to your question:

>, so for me the key drying issue is can we dry ~one tonne an hour 
>continuously using ~500KW of hot water at 90C thereby >enabling us to 
>derive revenue from the higher grade heat.

Only possible if the fuel has been cut and stored under cover for some time, 
so you are only just literally, polishing and preheating the incoming fuel.

 I have a drier that uses both the exhaust gas through a heat exchanger 
(250C in, 50C out) which has then the heat from the radiator and engine 
diluted with air to 50C, being blown over the heat exchanger up through the 
wood blocks.  While not built to do anything exept dry wood blocks in the 
most practical way, given it cost money in any language to do it better,
forest green to gasifier dry in one hour is a big ask.

One tonne of wood blocks as dry gasifier fuel will have a volume of about 
20x 44 gallon drums (4,000 litres) to put into perspective the size of the 
fuel consumption, so an air flow of 90C would not make much of an impression 
on wet fuel.

The large amount of low grade available from around a gasifier and engine 
installation, should be collected and ducted to establish an air flow 
through the incoming fuel bunkers, so that all fuel on site is in the drying 
mode. Until the fuel is dried to below 10% MC, the wood will take up 
moisture again depending on  the ambient conditions.

Hope this helps to scrutinise the actual operating conditions you view in 
Germany.

Doug Williams,
Fluidyne Gasification.