Algal Biodiesel Virtuous Cycles
Tuesday, July 15, 2008 at 08:16PM
Toby Considine in Energy, Re-thinking things

I am reading more and more about how close algal biodiesel is, perhaps a year or two away. I will reserve my judgment on ship dates, but note that there are claims that algae can produce oils suitable for making biodiesel out of without genetic engineering. I am not as concerned with genetic modifications as some are, but do acknowledge that the presence of such modifications would concern others and throw barriers up in the way of permitting.

Biodiesel algae seems to grow best in glass, where it can be exposed to maximum sunlight. It works best when micronutrients can be bubbled through it, although one plan seems to rely on osmosis through a filter from a waste stream.

But what I like best is that this algae (or any algae) seems to grow best when carbon dioxide is bubbled through it. Most of any oil is, of course, carbon and hydrogen, with a little oxygen perhaps thrown in. A good source of carbon is an essential fuel for plants. This is why plants in general, more popularly the rain forest, and more importantly, sea algae are such important consumers of CO2 and producers of oxygen.

Hmmmm – so biodiesel algae would work best with a ready source of carbon dioxide….

One of the fantasies I am enjoying most right now is algal scrubbing of CO2. I do not recall if I ran across this somewhere, or came up with it myself when tossing and turning on a late night. So here’s the deal.

Coal plants scrub their smoke stacks of any chemicals that may be harmful to algae. The result is then bubbled through a huge series of algae vats, which consume CO2 and release oxygen. The oil producing algae is harvested to produce biodiesel. The carbon in the biodiesel would, eventually, end up in the air, but not before another trip, through the nation’s cars and trucks.

Because of the scrubbing, coal becomes one of the cleanest ways to produce energy. The high costs of scrubbing are paid for by biodiesel production.

What’s your energy fantasy?

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