10 March 2006

Cellulose Ethanol

It's been a long time since I posted, since I'm sick of being a negative hater. Now, for something completely different. I've been doing a lot of research on cellulose derived ethanol. I've learned a lot.

  1. Current Energy Situation
  2. Why Ethanol?
  3. Why Gasohol?
  4. Why Cellulose-derived Ethanol?

Current Situation
There are lots of well-known problems with our current oil consumption. The 2 biggies in my mind are:
  • Greenhouse gas emissions (GHGs) aka environmental impact of burning fossil fuels
  • Dependence on unstable petro-regimes provides funding for terrorism


Why Ethanol?
In the past I have been guilty (as have many others) of seeking a utopian comprehensive solution to the above problems. But gasohol -- fuel that is part gasoline, part ethanol -- represents an incremental step in the right direction with a variety of dramatic impacts that can be achieved right now.

What's wrong with corn Ethanol?
Currently, there are approximately 5 million "flex-fuel" cars and trucks on the road today that run on E-85, which is 85% ethanol and 15% gasoline. The problem is that you can only get E-85 in the mid-west corn belt. While the program has good intentions, there is speculation that the only reason the vehicles are out there is that the manufacturers get a fuel economy credit. By producing the flex-fuel vehicles, they get a gas guzzler break and are allowed to manufacture more guzzlers without penalty. Further more, the corn-derived ethanol owes its existence to Federal Farm subsidies.

The output/input ratio for corn-derived ethanol is only about 1.2. When you factor in the incredible damage industrial agriculture practices do to the soil and the water (industrial fertilizer drains into the Mississippi and Missouri Rivers, the soil loses all its value over time, etc), you have something that is not economically feasible for the long-haul.

Further more, how the heck do you deal with the vast majority of automobiles that can't run on biomass out of the box? Biodiesel is great -- if you're willing to brew it up at home and have a TDI or a Benz that will run on it.

Why Gasohol?
Friends, I bring you gasahol. It's a 90/10 blend of gasoline and ethanol. Many states already require gasohol during the winter months, when issues with ozone are minimized. "Gasohol has higher octane, or antiknock, properties than gasoline and burns more slowly, coolly, and completely, resulting in reduced emissions of some pollutants, but it also vaporizes more readily, potentially aggravating ozone pollution in warm weather." (http://www.bartleby.com/65/ga/gasohol).

Many states (like Washington) have legislation on the books to require gasohol year-round -- if issues like ozone depletion, and "will it run on every car" get sorted. I don't have an answer about the ozone claim, but I'm sure it is not an unsolvable problem. Now for the good news.

Enter switchgrass...
The input/output ratio for switchgrass-derived ethanol is 4:1. Switchgrass can be farmed sustainably. This article from 1991 explains the utopian promise of switchgrass in detail. It can be refined using bioorganisms to produce sugar and then ethanol. In other words, you could have fully organic fuel in your car, just like organic milk or vegetables! The life cycle of sawgrass to fuel and back involves a net carbon dioxide reduction, as well as the reduced emissions benefits of ethanol. Further more, you can take ruined, eroding farmland, and it's cheaper to replant it with sawgrass than the eventual cost of letting it sit. So if you're tired of Red states sucking down all your tax dollars for inefficient subsidies, here's a way they can create an economic powerhouse that creates jobs, weens us from foreign oil incrementally while creating the infrastructure for nationwide E85, and is good for the environment. (The government of Canada has estimated that if 35% of Canadian vehicles ran off of cellulose-derived gasohol, the net effect would be like removing 400,000 vehicles off the road annually.)

The Brasil Story
It's also worth pointing out that the Brazilian government mandated the use of ethanol to reduce dependency on foreign oil. The current process they use gets energy in:out ratios of 1:8, and Brasil's scientists think they can get it up to 1:10 soon.

Brasil's advantages:
They already grew a lot of sugar
The government, including the military, imposed this system on the population in a rather undemorcratic and non-market-driven factor. See the NYT article for more details.

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