First American Scientific Corp. (fka FASC)

[techisbest]

email from the [e-mail] ...

One of the member's was asked to compare the different systems that were demoed at the AURI Dryer Days. His response:

Wow. That's quite an order. I do have a report I am working on for AURI that will summarize these and some others that will be out early next years. For now, here is a very brief summary:

Algaventures Belt Dryer - very interesting with very wet, liquid-consistency feedstocks, like algae (which can be less that 0.5% solids) or with the thin stillage from Al Corn Ethanol in Claremont, MN, which is pictured in the example picture of the dryer (about 12% solids). If you look on their website you'll see examples of "wicking" through a microfilter and how this speeds up water removal. There appear to be questions about how to remove water after it is dried to a certain point - for now I'll say ~ 30%.

Cellencor's Microwave Dryer - from our study of beet pulp drying (see www.auri.org) we found that the efficiency is at least equal to and the feed value better than traditional thermal drying. This may not be important if drying biomass for energy - for use in combustion or gasification systems.
In Cellencor's presentation on May 13 they intimated that microwave drying could in theory beat the 970 Btu/lb of water removed thermal limit due to the atomization of water that occurs when the material is exposed to microwave energy.
Microwave heating does have different properties also from thermal heating - the microwaves penetrating the material allow heating to occur within the biomass and not just at the surface. Industrial microwave systems have been implemented in the food industry for years (as well as lumber tempering) and Cellencor is just beginning to look at applications beyond DDGS in the biomass area.

GRRO's Tempest High Speed Air Cyclonic Dryer - this is also the dryer that Marion Mixers is improving next generation machines. I will let Greg post updates there when he shows up on the Group board.
In November meeting they claimed 800 Btu/lb of water removed with their most current installation in Cedar Rapids, IA. The day we went to Eldora, IA, in 2009 to test manure solids they were able to dry them from ~65% moisture to 11% with no heat and one pass - they came out of the dryer cool to the touch. I have personally seen this one have a lot of potential (as well as the previous two) because of the companies and their time and monetary investment in improving the technology.

The KDS Machine - The theory is sound - that the grinding action on the material increases the temperature and drives off material with that heat and the physical chopping. This is another group that claims to break the 970 Btu/lb of water removed barrier, due to the mechanical removal of loosely bound water. It will be interesting to see how the projects process at Minnesota Valley Alfalfa Producers with the KDS.

Tri-Phase Drying System's Heat Pump-Assisted Dryer - The theory is interesting (claims 500-600 Btu/lb water removed due to use of the heat pump) but I have not seen an installation. There was one near Waseca, MN, which is no longer up and running.

Energy Unlimited's Integrated Drum Drying Systems - the most traditional of our presenters at the Demos, this group points out that this is for a low value feedstock where the feedstock can be economically used as part of the energy source to dry more of the same feedstock. This system is already implemented with manure solids at Van der Geest Dairy near Wausau, WI, where they are using dried-down manure as bedding (dried to 20%) or further fuel for the system (10%).

There are other systems that I did not get time to see in action and therefore did not have to the Dryer Demos. The Rotary Biomass Dryer is one I did see, and continue to follow its progress, but have not seen in action.

Although in most case I won't be able to verify energy numbers in the AURI report, I will present what I have seen and do know about the drying systems as factually as possible.