Guys, have y'all been watching the news releases about Coskata's process to use household garbage and some special bacteria to make ethanol ? If you can get past some of V Khosla's hype, it still looks very interesting. We would be using a raw material that we seem to have an awful lot of, and it would be cheap. DF

 

Making ethanol from garbage or various waste products is noting new, the question is whether they make it in a liquid solution that has lots of water (as done with yeast) or they can make it without any, or much water?

As I've said it before, the Achilles heel of ethanol production is the distillation because it requires so much energy.

 

Here's a link to a flash animation about their process:

http://www.coskataenergy.com/process_movie.html

They convert the biomatter into "syngas" and then pump it into a bioreactor where microorganisms consume it to produce water and ethanol. The water is then seperated out of the ethanol.

Apparently it reduces the required energy by 50% and produces 100 gallons of ethanol per ton of biomatter.

 

I don't know of anything called "syngas", so until they clarify it, I assume it's probably methane (if they do the conversion at low temperature) or a complex mixture of hydrocarbons if they heat up the garbage.

 

You're right, it is a mixture. Here's Wikipedia's definition:

http://en.wikipedia.org/wiki/Syngas

I found the last sentence interesting:

 

My bad. Now I remember. (I actually studied that in school ) Historically, 'syngas' used to be made from hot coal and water; in addition, I should've checked out the link you posted before my previous reply.

In any case, the revolutionary thing in their process is the "proprietary membrane" -- that can certainly get around the distillation requirement and make ethanol production more competitive.