bobad -

The processes being used by IOGEN are fairly well known in the synfuel industry, but it requires an enzyme process to break down the cellulose, separation of the starches/sugars from some burnable (mostly solid) residue, a separate process for fermenting the starches into alcohols, and then distillation to recover the ethanol. Since each enzyme batch has to run to completion before the starches can be moved to fermentation, it's a "batch process" that's hard to convert to continuous flow processing - and hence probably "labor intensive?".

Even with the rising corn/grain prices, the requirement for multiple processes and complex processing makes it significantly more expensive than the more common grain fermentation/distillation methods in more common use.

Several groups have claimed to be "on the verge" of releasing (for commercial use) single "bugs" that will both break down the cellulose and ferment it, all in one pot. This obviously should be a much cheaper process - if sufficient yields can be attained - than the one(s) in use by IOGEN.

Resistance to building more plants of the IOGEN kind seems to be based largely on the belief that they will be obsolete - almost overnight - when (they say "not 'IF'") the new bugs are released for use.

Perhaps we'll know in a year or two.

Another development to watch, maybe, is the use of smokestack gases from coal fired plants as "food" for growing algae (green lake slime) that can be easily fermented to produce liquid fuels and clean up the stack emissions from the traditional stationary generating plants. Some results have been released that look "promising" but as yet this process is pretty much at the "pilot plant" stage. It also seems to require fairly large availability of water and good sunlight, which is something of a problem in some of the remote areas where people like to build coal-fired plants.

John