[Subjectivist]

As far as I can tell the only way to make bulk ethanol without using up food crops is to use yard waste cellulosic ethanol. The only practical way to make ethanol from cellulose is to first break it down into glucose molecules so your yeast can eat it. The only way to do that that is energy effocient is to grind the cellulose into fine mush and mix it with clean water an cellulase enzymes.

http://www.worthington-biochem.com/cel/pl.html

The biggest hold up is the cellulase enzyme is flipping expensive! Sure it is an enzyme catalyst so with proper procedure you get 85% of it back from each cycle and can use it for the next cycle again. However even if your yard waste of grass clippings and leaves is free the energy to grind it and the cost of clean water and kilograms of cellulase per cycle are going to add up in a hurry. I have yet to see a rigorous breakdown of the costs where all the inputs are accounted for, almost all of them make assumptions that some chosen feedstock will be grown like switchgrass. This is done so that federal subsidies can be set up for the chosen winner, not as the most EROEI efficient choice.

Our system n America is now dependent on government approval and subsidy to function.

[Subjectivist]

How did you ever find this thread? The 'advanced search' facility only goes back one year. (I have to search my own stuff to go back further).

Have you scanned previous posts in this thread? You will find 'Lorenzo' the original biofool. 'Lorenzo' even admitted to pumping some investor scam for some org or group. 'Lorenzo's the original Graeme, except with heart. He defended his crap nobly.

And yes, the number were done in 2005 by Pimentel. "About 57% more
energy is required to produce a liter of ethanol using wood than the energy harvested as ethanol."

I used search.php under Safari web browser by Apple, it pulls up everything back to day one of he archives for me.

I was hoping you or someone else might have something a wee bit more recent than 2005.

[Shaved Monkey]

Ive got to get the whipper sniper/weed waker out on the switch grass its taking over.
Just free mulch around here no bio fuel ....yet

[hvacman]

Cellulosic E - what a boondoggle! Research in CE has really collapsed the past few years. A lot of the pioneers are out of business. I was involved in some conceptual engineering work for a proposed CE pilot plant near Corning, CA back in 2009. The following link will download a pdf of about the best technical summary I found of actual CE plant energy inputs and outputs. It was completed in 2002 by the NREL. If the google link doesn't work, the report is Subcontractor report #SR-510-32381 and available as a pdf text download at http://www.osti.gov.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCsQFjAA&url=http%3A%2F%2Fwww.nrel.gov%2Fdocs%2Ffy02osti%2F32381.pdf&ei=AyN1U4r7CNewoQSto4GYCA&usg=AFQjCNGOTFtyQj_ImMI8h5dRNLf40zaAVw&sig2=qfRaXXzTjnlRJy3pWdb4ug&bvm=bv.66699033,d.cGU

[Pops]

I don't know about published papers but the EPA is expected to reduce the 2014 quota down from the 1.75 BILLION gallons mandated in the 2007 law.

75k was produced in the 1st qtr.

http://www.ogj.com/articles/2014/04/epa ... ndate.html

[Graeme]

I'll be interested to read comments about this analysis of eroi for biofuel produced from switchgrass. Note the authors. Quote comes from bottom of page 2428.

Seeking to Understand the Reasons for Different Energy Return on Investment (EROI) Estimates for Biofuels

Charles A.S. Hall 1,*, Bruce E. Dale 2 and David Pimentel3

Table 4 gives Dale’s estimates for the improvements in yield and reductions in energy costs for producing switchgrass. If all of these improvements in efficiency are realizable, as Dale thinks possible, then EROI for cellulosic ethanol from switchgrass might be doubled from 17:1 to 35:1. If the thermal efficiency of the biorefinery is increased (e.g., by ethanol and more net electricity produced in a gas turbine combined cycle (GTCC) system [26], then further increases in cellulosic ethanol EROI can be expected.

mdpi