[Gasification] low tar DTU two stage gasifier paper and comments

[Daniel Chisholm]

A disadvantage of the design is that its pyrolysis/drying chamber is
very large (have a look at the various photos).  This would translate
into large capital costs and space requirements.  Perfectly fine for a
research gasifier though.

Direct scale-up of this design's indirectly heated pyrolysis/drying
chamber would be a concern.  It is a relatively sophisticated piece of
gear (temps to 600C, internal feed screw, gastight) to be involved in
such a low-intensity process.  This could give a high capital cost per
unit of capacity.

As you note, its high H2 content and ability to handle high MC are
impressive.  I found its thermodynamics to be exceptionally well
designed.

I did read an article or two in which they mentioned plans for a large
scale design based on these principles, but using some sort of cyclone
design for direct contact pyrolysis.  This was at least two years ago.
I never did find enough detailed information on it to decide on its
merits.  At the time they suggested that they were in some sort of
commercial development partnership.

Don't go too hard on their low-tar claims being made at a constant load.
I think this is impressive enough in itself, and actually pretty useful.
There are a number of applications that can use constant or
near-constant loads (in fact, I'll propose one in my next email for your
consideration).  Just because an automobile requires a huge dynamic
range is no need to give up on a gasifier that is tar-free over only a
relatively inflexible load range.

-- 
- Daniel
Fredericton, NB  Canada