Wednesday, May 23, 2007


A common characteristic of bio-fuels is that their feedstock is squeezed, mashed, pressed, shredded or otherwise processed to get the juice out. I used to live next door to a cane plantation in Hawaii and we'd end up with sticks of cane to chew from time to time as a treat. Even bio-gas from manure is twice chewed grass. There is quite a lot of work that goes into making bio-fuels.

The reason all this effort might be worth it is that liquid (or gas) fuels are pretty convenient to use in machines with automated power control. Furnaces are run by thermostats so you don't have to build a fire early in the morning when you first wake up. Car engines respond quickly to the accelerator rather than waiting for a head of stream from a boiler. Gas stoves heat right up rather than waiting for a wood fire to light. Pellet stoves are an attempted compromise, getting the fuel to flow by using smaller pieces, and hauling the sacks of pellets might be an adequate substitute for the swing of the splitting maul for those who like a bit if ruggedness, but pellets still don't flow through a pump.

Liquid fuels are easier to control as they burn, leading to higher efficiency engines and lower pollution with the addition of catalytic converters which would be poisoned by low temperature combustion products.

On Monday, I went to a conference that was mostly about how to divvy up the work of juicing the various feedstocks so that it would make sense to use these potentially real energy sources instead of ghost energy sources. The conference was organized by the Maryland Secretary of State's office as part of a sister state program with Brazil's Rio de Janeiro state that has been ongoing for a number of years. Brazil has the greatest experience with biofuels and so there was quite a lot to learn from the attendees from there.

The first presentation was given by Paulo de Sousa Coutinho of Brazil Ecodiesel. This presentation was impressive and I'm just going to steal figures from it to give an idea of the thought and planning that has gone into this effort. So, let's take the Energy Balance figures he gave:

Corn (US) 1.3
Beet (EU) 1.9
Cane (Brazil) 8.3
Soy (US) 1.9
Rapeseed (EU) 3.0
Sunflower (EU) 3.2
Castor bean (Brazil) 10.5

Now, Energy Balance is being used in a particular way here. It is the ratio of real energy out to ghost energy in. So, if it takes just as much energy from natural gas to produce the fertilizer for an energy crop as you get out in energy, then the value would be one. Now, let me say that some at the conference calculated the value for gasoline to be about 0.7, less than one, and this use does not make a lot of sense because there is no real energy out in the case of gasoline, but perhaps this was just an illustration assuming the numerator was nonzero. In any case, the numbers can be changed in the denominator as well by including more real energy in the production process. De Sousa Coutinho made this point rather dramatically when he pointed out that as soon as ethanol can be used instead of methanol for transesterification of plant oil to biodiesel, then the Energy Balance for their castor bean feedstock shoots up to 40. Similarly, for corn, which is very nitrogen hungry, substituting solar fertilizer production would raise its rather low value. Part of Brazil's high numbers are owing to their advances in real energy. Their farm equipment runs partly on ethanol for example. They are also planning for efficient use by spreading production of biodiesel across Brazil in close cooperation with unions. They expect 100,000 farmers this year. With more and more real energy bootstrapping all of these numbers head to infinity as the denominators go to zero. Since real energy is free, anything that has a positive (real) net energy gain should be fine.

Or should it?

While real energy just makes sense and we'll laugh at ourselves for our flirtation with ghost energy as one of our greatest follies, let us not forget that we are being pushed back to sanity by a crisis. We are stressing the ecosystem that sustains us, and we don't have a lot of room to make mistakes just now. If we make liquid fuels too high of a priority, we can make mistakes that may not be at all easy to recover from. Both de Sousa Coutinho and Alfred Szwarc, who presented next on ethanol in Brazil, emphasized the sustainability of their efforts and particularly that neither castor beans nor sugarcane are grown where the rain forest areas are. Why is this a sensitive topic? In part because EU demand for biodiesel has led the the deforestation of rain forests to produce palm oil and this causes much more carbon dioxide emission than using ghost energy because the peat in the soil rots. Oops....

There was another area of discomfort at the conference: $4/bushel corn. May people were quick to say its about time and this can't have anything to do with the price of tortillas. People were quick to point out that an extra $50 a year in grocery costs were nothing compared to the high gas prices we're seeing.

This is spin. High corn prices and high tortilla prices are related in a fundamental way and saying someone else is worse (OPEC) is not saying what you are doing is good. There are big problems with low corn prices but they are based on some pretty ancient wisdom: in Genesis 41 skinny cows eat up fat cows. Ensuring a surplus of grain avoids famine and surpluses mean low prices in a market economy. If we are seeing higher corn prices, we need to look to see if our policy for avoiding famine is still working.

In any case, Maryland seems like a good place to grow energy crops and it was interesting that barley came up at the environmental breakout session. This is a winter cover crop so it hardly seems like it is competing for food production. In Maryland, what we are really missing is our huge oyster harvest, the shells of which happen to sequester permanently about 30% of the carbon dioxide emission from cars in Maryland when it is at historic productivity. At this session Tom Simpson from UMD spoke on the impacts of bio-fuels on water quality and especially what fertilizer does to the Chesapeake Bay. You have to be smart about this kind of thing but I do wonder what oyster oil smells like run through a diesel engine?

Some people like their oyster raw
To feel it slither down their craw
I prefer my oyster juiced
To get the temperature reduced.

With apologies to Roy Blount Jr.

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