All:

I attended a Biofuels Symposium yesterday at the U of M which featured six speakers from the U of M , UC-Berkeley, Princeton University and US DOE.   Following are some highlights, research findings and suppositions raised by the speakers:

"1st Generation" biofuels are defined to include grain and plant oil fuels (i.e. ethanol and biodiesel) "2nd Generation" biofuels are defined as cellulosic (grasses, trees, muni waste, misc biomass)

1st Generation

The production of corn ethanol is a fossil-fuel intensive process which yields a 25% net energy gain (energy inputs vs outputs); in contrast biodiesel yields a 93% net gain.  However, when true production costs are factored in, corn based ethanol yields only a 2% net gain.  Biodiesel production today is where ethanol production was 25 years ago -- much potential here. Biodiesel also produces far fewer greenhouse gas emissions compared to ethanol, gasoline or regular diesel.  If all available cultivated acres in U.S. were used for corn and soybean production, and all grain produced was converted to biofuels, it would replace only 12% of current gasoline demand and 6% of diesel demand.  In order to actually eliminate our dependency on foreign oil at most 1/3 could be achieved via use of biofuels, the other 2/3s would have to come from improving efficiencies and conservation.  By 2015 it is very realistic to produce diesel vehicles which achieve 80 mpg.  Almost none of the 1st gen biofuel production today is sustainable in the long-term.

2nd Generation

The Good News:  Make friends with a new acronym "LIHD" - Low Input High Diversity - grassland biomass.  Research (at the U of M) has shown that LIHD grassland, defined as a mix of 16 perennial herbaceous grassland species, yielded 238% higher bioenergy yields than monoculture yields (read: switchgrass stands) after a 10 year period (1994-2004).   LIHD plots actually produced more energy as they aged; they are also carbon negative (sequestering more carbon than is released during biofuel production).  Plus, LIHD can be produced on degraded ag lands (and were in the experiments) so little displacement of food production.   We don't know what LIHD yields would be in productive soil (presumably greater still).  LIHD stands require almost no inputs (fertilizer, replanting, pesticides) once established.

The Bad News:  2nd Gen fuels require about a 5 gals of water for every 1 gal of fuel produced (5:1).  And we have still not discovered the "magic" enzyme which will enable the efficient breakdown of cellulose, but expect to do so within the next five years.

Misc.

To motivate and make it cost effective for ag producers to convert from grains to LIHD production it is believed that 1) crop subsidies must be removed, and 2) a payment for carbon credits @ $100/ton level must be in place.  Based on current economics, a biomass conversion processing plant would need daily inputs of 2,000 tons of biomass in order to be cost effective.  The conversion to and acceptance of biofuels is likely a 50 year process; it took 100 years to get where we are today with fossil fuels.  Should not expect a quick fix.  Once introduced, CO2 lasts 100 years in the climate.  We are on the cusp of much more research into carbon sequestration and carbon crediting.

It was an interesting symposium although clearly there are more questions than answers about biofuel production. I have a copy of the U of M LIHD study summary (4 pages) if anyone would like a hard copy.