Gian Claudio Faussone, October, 2011
The Italian group INSER has come up with a gasification process that they have patented as Circle Draft.
As described by them, the reactor vessel is composed of two chambers.
In the top chamber, the feedstock is pyrolysed and converted to charcoal (which is the yellow in the figure).
Then the charcoal descends into the lower vessel (grey in the figure) where it is gasified (generally with additional air) and a variable amount of steam or water.
G. Sridhar and Ravindra Babu Yarasu June, 2011
We are pleased to learn of this paper, in which Sridhar and Yarasu connect and engine that is designed to run on producer gas to a downdraft gasifier, and learn a lot of new things; one of which is that the engine runs efficiently at a higher compression ratio without any problems with knock. They do a great job of presenting the results from their trials, and then comparing standard modeling tools and finding where the gaps are. Well worth the read.
I learned from Johannes about this forum. Just like Johannes, I did a PhD at Paul Scherrer Institut and the Swiss Federal Institute of Technology in Zurich in the field of Biomass Gasification. I wish I had known this forum back then because one of the goals of my thesis was to come up with a fixed bed gasifier in the 5 to 30 kWth scale which would operate at least one week non-stop. Fortunately, I did succeed in the end as you can read in my thesis.
Electricity from wood through the combination of gasification and solid oxide fuel cells
IEA Task 33 Thermal Gasification of Biomass: Technical Presentations from the Fall Meeting Oct 30-Nov 2, 2006 Chicago, Golden, USA