US MicroGrid seeks to Fund Torrefied Wood Absorption Chilling Application

We're busy sifting through all the data and opinions to come up with (and publish) the reality behind the economics of Torrefied Wood.

Absorption Chillers are amazing things. They might represent the best first application for Torrefied Wood. For more about how they work you can read http://tristate.apogee.net/cool/ccaa.asp.

They take in relatively low grade heat, and produce chilled water while displacing electric chillers that consume peak load electricity

We've had some experience with absorption chillers on the back end of a cogen project we developed. They work as advertised however it is difficult to find skilled maintenance workers (outside of the NYC area where they are more prevalent because they run off the underground steam loop).

Torrefied Wood input to a boiler which creates hot water or steam to drive an absorption chiller would have the following benefits:

1) Friendly conversion efficiencies: Electric chillers have an average efficiency of around 75%. When you compare full system efficiencies of biomass in a cooling application (vs. producing electricity) you pick up this 25% and that's significant. For more specifics, see and please feel free to comment on the attached spreadsheet.

2) Good scale of operation for a demonstration plant: We've learned to "learn small then scale".

So we are actively looking for a host industrial or commercial project to run the numbers on a torrefied wood boiler driven absorption chiller. Our company would fund the project and own and operate the equipment for a client who would agree to buy the chilled water at the then current equivalent cost of electric cooling.

In the first phase, we would probably purchase torrefied wood and/or pellets from an existing supplier to fully field test the system. With economic success, we'd purchase equipment and generate our own fuel. The benefit of a couple of torrefied wood absorption chilling clients would be that we could have captive demand for part of our torrefied wood production bringing in our break even point and reducing overall business model risk.

If you know of a company or institution that would be interested in the 'offtake' agreement (agreeing to buy the chilled water) please let us know. Contact info is on our website www.usmicrogrid.com.

Excellent Overview of Chemical Process of Torrefaction

Kristoffer Persson, Ingemar Olofsson and Anders Nordin from Umea University in Sweden have started publishing on the topic of Torrefaction.

Click on the Title of this Post or the link below for a good explanation of the chemical process, it's advantages, and some preliminary evaluation of biomass stocks.

http://www.techtp.com/Biomass%20Refinement%20by%20Torrefaction.pdf

Link updated 9/04/2009

Agri-Tech Producers Demonstration Plant

The SC Biomass Council http://www.scbiomass.org/ announced that Agri-Tech Producers has been awarded a grant to develop a demonstration project of portable bio torrefaction unit.

By moving 'the factory to the field' the benefits of torrefaction are amplified.

By removing the moisture and reducing the mass through torrefication, the economics are improved over approaches which truck green chips to a torrefaction facility.

Two test burns of torrefied wood are scheduled for this year. Stay tuned.

Torrefied wood chips project, Sumter National
Forest - Agri-Tech Producers, LLC ($200,000)

Bio Torrefication

Through all the noise out there right now, we look for ideas that could truly make a difference. Our criteria is:

1) The technology must be at least 35% Carbon Positive

2) The potential scale of operation must be large enough to deliver 10% of the current US Demand for electricity

3) The cost, post inflection point, must be 20 cents per kWH or less Without subsidies and tax credits (because the government can't afford to subsidize all our consumption).

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One that has real potential is Torrefied Plant Material. New work out of NC State is showing some interesting numbers for a unit which converts plant material into a powdery charcoal like material in the field.

The numbers look promising, because the cost of material handling is significantly reduced. In most waste-to-energy applications, the cost to move and handle low BTU material creates the barrier to economic viability.

Furthermore, the resulting fuel (think charcoal chips and powder) can theoretically be co-burned with coal in existing power plants. This is what makes it exciting. A power producer could have a renewable fuel which could be added based on the relative cost of delivered Torrefied BioMass to Coal.

Two 'test burns' are scheduled for 2008. We'll be monitoring this space. Check back or contact us for updates.

If current Torrefied Pine Wood can be utilized in a coal fired plant, the next step to viability would be developing plant species for BTU value vs. food value or fiber strength. The ideal feedstock would be the kind that grows on marginal land, avoiding the current ethanol "Fuel at the expense of Food" debate.