A few weeks back, I went to the weekly flea market at the fairgrounds. I love books, so I pawed through every book collection there. We’re running out of shelf space, so I bought a few choice ones. This particular trip, I picked up Isaac Asimov’s New Intelligent Man’s Guide to SCIENCE: Vol II, The Biological Sciences.

Now, I’m a sucker for Asimov’s non-fiction. In fact, Asimov’s prolificness and my readitude of it won me a trip to Hawaii (but that’s another story). Anyway, just judging by the title, I knew this book was bound to be good: to hell with you Old Intelligent Men, you Non-Intelligent Men, and ALLLLLL you Women!

So I’m cruising through the first couple of chapters, right up to the part about photosynthesis. Now there’s something I haven’t thought about since high school biology. As we all know, photosynthesis is how plants take light, plus water, plus carbon dioxide, and turn it into oxygen and carbs (those evil, evil carbs!). In particular, the chlorophyll in the plant uses the light energy to break up water molecules into hydrogen and oxygen.

That’s when the light went off. As you know, there’s a meme floating around the zeitgeist that we need to stop burning fossil fuels as energy sources, and use hydrogen instead. Using pure hydrogen as a fuel has a great upside, because it’s clean burning (producing just water as a by-product) There’s just one problem: There ain’t no pure hydrogen on earth.

Oh, there’s some, but the problem with hydrogen is it tends to buddy up with other elements and form compounds. That’s why I haven’t really paid much attention to the talk about burning hydrogen as an “energy source,” because it’s NOT an energy source; you have to expend energy breaking the hydrogen loose from whatever compound it’s in. Hydrogen could be used as an energy storage and conversion medium, but producing hydrogen by, say, electrolysis of water, is still a losing proposition if you’re getting the electricity from a coal-fired power plant. OK, you could probably take advantage of some economy of scale, but the dirty coal is still being burned. Sure, we could use solar cells, but then you have to put energy into creating the cells.

But what if you could grow your hydrogen-producing system? Bio-engineer what would literally be a “power plant?” This idea struck me just now when reading Asimov’s book. And whenever I have moments like this, I think, “Either this idea is so incredibly stupid that only Dilbert’s boss could come up with it, or else somebody is already working on it.”

Well, actually, both could be true, but at any rate, somebody is already working on it.

For several decades, we have known that green algae can produce hydrogen directly from water….Scientists at the University of California, Berkeley, have found that sulfur deprivation of Chlamydomonas reinhardtii, a green algae, turns off the normal photosynthesis pathways, causing cells to stop emitting oxygen and stop producing carbohydrate, protein, and fat energy reserves. Hydrogenase is induced and activated by the low oxygen tension, and the stored energy reserves are then used to produce hydrogen. Once the stores are depleted, sulfur must again be added to return the system to normal photosynthesis. By cycling between sulfur and non-sulfur metabolism, hydrogen can be cyclically produced in a two-stage process.

There’s actually quite a bit of interest in the idea of biological hydrogen production. If you, loyal readers, have any expertise in this, please leave a comment. Also, feel free to point out any pointy-haired boss (PHB) moments I might have had in this post.

Posted in uncategorized on April 11th, 2004 by Thibodeaux | RSS 2.0 |