2 minute read

I read the below article in Wired a few days ago and was so struck by it that I had to write about it here.  A friend and I had talked about this very topic the previous Sunday while hiking south of Denver, so this was already on my mind.


The article stresses that the process itself involved in the production of ethanol is fairly straight-forward:

  1. Thermochemical treatment  The raw plant feedstock is treated with chemicals — often diluted sulfuric acid — to break down cell walls and make the cellulose accessible.
  2. Enzymes    A mix of cellulase enzymes is then added to convert the cellulose and hemicellulose molecules into the simple sugars glucose and xylose.
  3. Fermentation    Yeast or bacteria are added, converting the sugar into a mixture of ethanol and water, what refineries call “the beer.”
  4. Distillation    The ethanol is refined and purified, producing a fuel that could one day end up in your gas tank.

This echoed what I already knew (at least marginally understood anyway), but I was surprised to hear that the biggest barrier to large-scale production of ethanol is the molecular structure of cellulose, and the difficulties involved in breaking down that structure.   I was under the impression that this particular problem had been solved & was scalable. There are approaches, to be sure, of breaking down cellulose to produce cellulases, but apparently none so far has proven cost-effective (translation: it isn’t profitable).

I was even more surprised – pleasantly so – at the amount of research currently being funded on this & other renewable energy sources.  I had argued with my friend that substantial research wasn’t being conducted into renewable energy sources now, mostly because the political climate didn’t favor it.  I was wrong, and that’s great.  I do feel somewhat vindicated, though, to see the Wired article point out one of my primary assertions:  that when Reagan declared the energy crisis over in the 80s, federal funding of energy research vanished nearly overnight.  And it has taken twenty years to correct that mistake.

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