An Open Letter to Ethanol Factories

Posted on October 17, 2005. Filed under: Vehicles - Ethanol |

John Frantz, a physican and renewable energy advocate from Monroe, Wisconsin, offers his thoughts on ethanol:

The manufacture of ethanol for fuel from corn is wasteful of energy because the energy required to plant and harvest the corn, plus the energy to ferment and distill it, approximates the energy in the product ethanol. All green plants produce sugar (almost always glucose) by photosynthesis in the leaves. This is transported to their seeds and the inner layer of bark (cambium layer) where it is converted (polymerized) to starch for storage. This is why peas are at their best when freshly picked before the new sugar arriving from the leaves has been converted into starch. Starch is easily converted back to sugar for use by the embryo plant or in the mother plant for its own new growth especially in the spring.

Ethanol production whether whiskey, vodka or as a gasoline additive utilizes embryo plants (almost always barley) to digest other starch from corn, potatoes, rice, etc. The resulting sugar is fermented by yeast to ethanol and carbon dioxide—hence the fizz in beer and champagne. When glucose is polymerized to cellulose (woody fibers) instead of starch, this is a one-way street as far as the plant is concerned. Cellulose is degraded biologically only by soil bacteria whether in the soil or inhabiting termites or other animal intestines. If we could devise an industrial scale artificial termite intestine, crop wastes and sawdust would be the feedstock instead of cornstarch (the only portion of the corn converted to ethanol in our present ethanol factories). How do tiny termite bodies manage to retain the bacteria needed to digest cellulose by a continuous process (as opposed to a batch process like the fermentation followed by distillation in an ethanol plant)? Continuous processes are almost always much more efficient than batch processes—an axiomatic precept in chemical engineering. It would seem that the bacteria that do the work for termites would be expelled from such a small insect body long before they got the job done. The interesting answer is that the bacteria inhabit spaces among the hairs of a hairy paramecium (a one celled animal much larger than bacteria and much smaller than termites). The paramecia swim up stream in the termite intestine like miniature spawning salmon, carrying the bacteria forever upstream where the chemical action is happening.

A team containing microbiologists and chemical engineers should promptly solve the straightforward assignment of devising an industrial scale termite intestine. They probably wouldn’t even need the paramecia because of economies of scale. It also happens that termite digestion can be tuned in the laboratory to produce various chemical entities from methane to hydrogen and in a rather pure state. Methane is easily converted to methanol, which is interchangeable with ethanol as a fuel additive. So, when (if) the hydrogen economy blossoms, our new factories could be adapted to become geographically distributed producers of hydrogen, incidentally obviating some problems in transporting the hydrogen to its users.

It is notable that 10% ethanol in gasoline is an excellent and sufficient octane enhancer. Also it is totally nontoxic unlike tetraethyl lead and methyl tertiary butyl ether. (Don’t drink anything that is mixed with gasoline).

In summary, non-beverage ethanol production is wasteful of energy unless the ethanol can be produced from a feedstock of waste material.



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