Researchers at Iowa State University have coined an innovative process to transform agricultural waste into bio-oil. A development that brings us one step closer to a closed loop energy system. The oil can be used for "boiler fuel and perhaps transportation fuel." The feedstocks are currently cow manure and corn stalks, but they expect to be able to proccess other agricultural wastes in the future.

First, the manure needs to be dried so it can be burned... That makes it possible to move to the next step: rapidly heating the mixture in a bubbling, fluidized bed reactor that has no oxygen. It's a process called fast pyrolysis. The process thermochemically breaks the molecular bonds in the mixture. It produces charcoal that can be used to enrich soil. And it produces vapors that are condensed to a thick, dark bio-oil."

Samy Sadaka from the Center for Sustainable Environmental Technologies figures if half the animal manure in the country were processed into bio-oil, that would produce the equivalent of 45 million tons of oil.

Definitely an emerging technology to keep your eyes (and nose) on!

Now *this* is a biofuel that makes sense. Don't use food for fuel, but use waste instead.

Posted by: Alfred on July 30, 2006 10:32 AM

The article didn't answer one important question: how much energy input does this process require? I.e., what the *net* energy yield? (The article describes the gross yield, ignoring any costs.)

In the drying stage, there's the energy needed to run the fan and to turn the mixture.

Then there's the energy needed to rapidly raise the temperature in the "fast pyrolysis" stage. How is that done? The article doesn't say, but it seems to me that this is where the energy budget might go into the red -- enough to make the whole process uneconomical.

More info please!

Posted by: Charlie on July 30, 2006 2:59 PM

I wonder how well the process would work with Human-ure. We already place it in a little container....

Posted by: Daniel N Smith Jr on July 31, 2006 8:44 AM