Ethanol from Cellulose

Ethanol from Cellulose: Too Good To Be True?
This page was last modified May 25, 2000.

What is ethanol and why should you care?  Well, ethanol is a liquid fuel that can be made from all forms of biomass.  While most current ethanol production comes from corn grown in the Midwest, it can also be made from cellulose, ie, trees--including your trees.  Government and industry now see ethanol as the primary renewable liquid fuel for the future.  A Department of Energy (DOE) brochure says that ethanol is:

  • A domestically produced liquid fuel from renewable, virtually inexhaustible domestic resources
  • A nonfossil transportaion fuel that contributes little, if any, net carbon dioxide to the atmosphere during production and use
  • A high-octane fuel that can contribute substantially to the U.S. automotive fuel supply
  • A fuel that an be used as a blend, a component of ethyl tertiary butyl ether (ETBE), or as a pure fuel, with excellent efficiency and performance
  • A potentially clean-burning fuel that reduces smog and emissions of carbon monoxide

NREL Photo 

So there is definitely some ethanol in your future, and probably in your forest's future.  But where will it all come from?  And at what costs to our forests and farms?  More government information on these questions is available from the DOE's Office of Transportation Technologies  and Oak Ridge National Laboratory  web sites.  Industry web sites include the Ethanol Renewable Fuels Association  and BC International , the leader in cellulose to ethanol technology. 

Some government and industry publications would have us believe that there are plentiful biomass resources, and that it's simply a matter of converting our car engines from gasoline to ethanol.  They generally don't say how much of our biomass resources are already spoken for by human agriculture and forestry, plus other non-human forms of life.  This is an issue that deserves some careful consideration

It's more than just an academic issue because, according to many senior oil geologists and engineers, oil fields everywhere in the world are now in decline--except those in the Persian Gulf--and it won't be long until these fields begin to decline too.  When that happens, oil and other energy prices will rise steeply, and demand for renewable energy sources like ethanol will also rise steeply.  Some oil geologists and engineers say we are in for a major oil shock as soon as the next year or two because Persian Gulf producers are already unable to make up for the loss of production in other parts of the world.

Government and industry publications tell us that most of the demand for ethanol feedstocks will be met by "energy crops" of switchgrasses, poplars and willows.  Most will be genetically engineered .  These supplies will come from conservation reserve and crop set-aside lands.  Other supplies will come from urban wood wastes, sawmill residues, forest thinnings, and agricultural residues.

The spreadsheet screen capture below illustrates what ORNL researchers think the supply of cellulose feedstocks could be in eight years at $50 per dry ton.  This should be the going price for wood chips when oil hits $30 per barrel.  It seems like a reasonable scenario--one that would not dislocate existing agricultural or forest industries, and that would supply about 11% of the nation's vehicle fuel needs.  With oil at $30 per barrel, this scenario could be played out, provided ethanol plants could be brought online quickly enough.

 

Notes on spreadsheet screen capture: References 1-7 are given below.  Copies of this spreadsheet are available upon request from Karl Davies.

But what happens if oil goes to $60 per barrel?  Or how about $120 per barrel?  Price increases of these magnitudes occurred during the early 1970s, and were only dampened by discovery of new oil fields in the North Sea and Alaska.  Now that these fields are in decline, and discoveries of new oil fields have slowed dramatically, will there be another deus ex machina to save the world oil economy when supplies fall short?  If not, oil prices could easily go to $240 per barrel and up in short order. 

We saw a huge increase in the cutting of cordwood after the oil shocks of the 1970s because wood heat had become much cheaper than oil heat.  Another oil shock will make this happen again, but there will also be a huge increase in cutting for wood-fired power plants and ethanol plants because the technologies are much more mature now than they were in the 1970s, and because there are more power plants, plus many more cars and trucks on the road.  Oil shocks come quickly, not giving people time to plan for oil substitutes.  There won't be time to plant energy crops and wait around ten years for them to grow.  There will hardly be time to wait for the ethanol plants to be constructed.

So here's how the next oil shock might play out in the woods:  After the short-term rationing and associated chaos, we'll see ethanol plants under construction everywhere except in the deserts.  But while they're being built, much wood will be cut for home heating and for hastily converted oil-fired power plants.  Government forestry agencies will make TV ads and booklets extolling the virtues of clearcutting for energy supplies and wildlife.  They'll also tell us that our forests are biologically over-mature and in need of "rejuvenation."

Foresters and loggers will probably get extra fuel rations.  If the situation gets really bad, they might be conscripted in some fashion to serve the national interests by "producing" more cellulose feedstocks to feed the ethanol plants.  Landowners may see their forests condemned by the state for the same purpose.  Of course the government would turn over appropriated lands to Exxon-Mobil-BP-Texaco for actual "management" of the biomass resource.  

On the positive side, we'll finally get mandatory paper recycling because most of the pulpwood needed for making paper will now go for ethanol.  We'll see public money spent on public transportation.  There will be lots more bicycles and power-assisted bicycles on the road.  Fuel cells will be specially designed to run on ethanol.  There will be national campaigns for people to go vegetarian so that land devoted to pasturage and grain production for livestock can be converted to energy crops.    

Prices for photovoltaic (PV) panels will come down and will be installed on many roofs.  Large PV arrays will be installed in sunny, desert areas.  Windmill farms will pop up wherever there's enough steady wind.  If huge efforts are made in energy efficiency at the same time, there might be enough solar and wind electricity to satisfy most residential and commercial demand.  Industrial demand will be another matter.    

Meanwhile, forests will keep disappearing into the maws of chippers for ethanol feedstock production.  Then at some point it will become clear that we face a critical choice: our forests or our cars?  It will still be years before all the energy crop plantings will be ready to harvest.  For most people this will be a very difficult choice.  Oil and car company propaganda won't make matters easier. 

We can only hope that Gaia won't get too perturbed with all this, plus all our other crimes against her, and just decide to shut us all down by means of massive forest fires, insect infestations, diseases and diebacks induced by climate change.  We'll have to hope that the same fate doesn't befall the energy crops.  And we'll have to hope that we don't get a climate "flip-flop" back towards glacial conditions just when we're busy at adapting to life without fossil fuels.  The timing would be just too much.

References

(1)
Biomass Resource Estimates
Dr Marie Walsh
Oak Ridge National Laboratory

(2)
The Economics of Biomass Production in the United States
Robin L. Graham, Ph.D., Economist, ORNL, Oak Ridge, TN, USA
Erik Lichtenberg, Ph.D., University of Maryland, College Park, MD, USA
Vernon O. Roningen, Ph.D., Economist, ERS-USDA, Washington, DC, USA
Hossein Shapouri, Ph.D., Economist, OENU-ERS-USDA, Washington, DC, USA
Marie E. Walsh, Ph.D., Economist, ORNL, Oak Ridge, TN, USA

(3)
Acreage: National Agricultural Statistics Service
USDA, Washington, D.C.
Released June 30, 1999, by the National Agricultural Statistics Service (NASS)

(4)
The Eastern Non-Industrial Private Forests
Gerald D Hertel, Assistant Director, USDA Forest Service, Northeastern Area,
State and Private Forestry, Forest Health and Management, Radnor, PA

(5)
How Much Energy Does It Take to Make a Gallon of Ethanol? [optimal scenario]
David Lorenz and David Morris
Institute for Local-Self Reliance

(6)
Table 10. Estimated Consumption of Vehicle Fuels in the United States 1992-1999
(Thousand Gasoline-Equivalent Gallons)
Alternatives to Traditional Transportation Fuels 1997
U.S. Energy Information Administration (DOE)

(7)
Ethanol Powered-Vehicles
California Energy Commission