Algae - Fuel of the Future?greenspun.com : LUSENET : TB2K spinoff uncensored : One Thread
You'll Never Look at Algae the Same Way Again--or So Researchers Hope http://www.latimes.com/news/science/science/20000228/t000019201.html
By LEE DYE
Scientists have discovered an astonishingly simple method of producing the "fuel of the future" from ordinary green algae, but Americans may have to learn to love pond scum. A "metabolic switch" discovered by researchers at UC Berkeley causes the algae to stop producing oxygen and release hydrogen instead, offering the promise of cheap production of a renewable fuel that could someday power everything from cars to cell phones. The significance of the discovery hinges partly on whether the process can be scaled up to an industrial level, and experts are optimistic that it can. The research, sponsored by the U.S. Department of Energy, could be a major step toward the day when hydrogen gas can be used on a large scale to power fuel cells, which produce electricity in a process similar to a battery. The only byproduct from a fuel cell is water that is so pure you can drink it, according to researchers in the field. But researchers have been stymied in their efforts to produce hydrogen gas in large quantities. "This is exciting to us, at least from a scientific perspective," said biochemist Michael Seibert of DOE's National Renewable Energy Laboratory in Golden, Colo., who is a collaborator on the research. What remains to be seen is whether it can be refined to the point that it is commercially viable, Seibert said. Because of the difficulty in producing hydrogen, fuel cells have been limited to uses where they are essential, such as aboard the space shuttle. Scientists have known for nearly 60 years that algae can produce hydrogen, but they have been able to pry the gas loose only in trace quantities. The experiment at Berkeley produced far more hydrogen than anyone else has been able to extract, said Tasios Melis, a microbial biology professor. And it all came about because of a bit of serendipity. While some researchers in his lab were trying to find the "molecular switch" that would turn on the hydrogen producer in the algae, others were working on quite a different problem, also involving algae. The second group was studying protein production in the algae. The algae's diet must include sulfur to produce protein and, in an effort to slow down that process, the researchers reduced the level of sulfur, in effect "starving" the algae. It turns out that denying sulfur to the algae turned off photosynthesis, and the cells in the algae stopped producing oxygen. That was exactly what the other researchers had been trying unsuccessfully to do, because they thought that if they could shut down photosynthesis, the algae would switch to an alternative method of survival, respirating hydrogen instead of oxygen. Melis said the two paths of research caused something in his mind to "click." "I thought, 'My God, I'm looking at the switch,' " he said. "This is what we have been trying to find." Melis and researcher Liping Zhang began an experiment by denying the algae its sulfur. Within 24 hours, photosynthesis shut down and the algae stopped releasing oxygen. But then an astonishing thing happened. Bubbles began rising in the liter-size bottle of algae, which looked a little like green tea. "We were saying, 'God, what is this coming out?' " Melis said. " 'Is it oxygen? No. Where would it come from? There is no oxygen activity anymore.' " Seibert's lab repeated the experiment, and then used sophisticated equipment to confirm that the gas was indeed pure hydrogen. The algae continued to bubble away, producing about a tenth of a fluid ounce of hydrogen per hour. That may not seem like much, but in the world of hydrogen production, it was a gusher. In the past, before the discovery of the switch, algae produced so little hydrogen that it could not even be seen, Seibert said. Now, he added, "We can see bubbles [of hydrogen] coming out of the algae." Melis believes that the yield from the first experiments can be increased tenfold, and that is the focus of the current research. He said a small pond of algae should produce enough hydrogen to run a dozen cars. But how many ponds of scum can we stand? Seibert, admitting he was on a "dangerous" course of predicting the future, speculated that if the process can be perfected, the real estate demands may not be all that great. At least not when compared with other energy sources that also have high demands, such as oil fields, coal mines and power plants. It would take an area roughly the size of New Mexico to produce enough algae to satisfy all the current energy demands for the United States, he said. "That's not to say it would all be in New Mexico," he added quickly. Any warm area with lots of sunlight and access to water--possibly even seawater--could serve the purpose, Seibert said. Algae already is produced on an industrial scale in California's San Joaquin Valley for such purposes as food supplements and chemical extraction. The hydrogen production process is renewable in that it doesn't kill the algae, the researchers said. After about four days, the algae has used up all its stored carbohydrates and other fuels and, if sulfur is returned to its diet, photosynthesis restarts and the algae refills its energy warehouse. Then the "switch" can be thrown and the process starts all over again. Capturing the hydrogen from scum ponds would not necessarily call for a high-tech solution. "The other day I was watching my 16-year-old son pull the tarps over the swimming pool where he works as a lifeguard," Melis said. "I thought, gosh, if these tarps were airtight, they could cover a pond and trap the hydrogen. Then you could bleed it off and collect it. "You may not need to employ any fancy systems."
-- cin (email@example.com), March 06, 2000
GREAT!!!! I'm ahead of the game! I got some growing in my diesel NOW!
-- Squirrel Hunter (firstname.lastname@example.org), March 06, 2000.
Definitely a technology to monitor. But bear in mind the limitations of so-called "renewable" technologies---the Second Law of Thermodynamics: All closed systems run down. Frictional and conversion losses will see to that. Entropy is a bitch.
Given: our planet is not quite a closed system. We are treated to an influx of solar energy at about 1 Watt/meter^2 maximum full sunlight. Divide that by 4 to get a high average (not counting cloud cover losses). Divide that by available land area to get total Kw potential worldwide. Divide that by Kw (or horsepower) requirements of the human enterprise and you'll find we come up woefully short.
The only reason we can function at the current level is our use of stored energy produced by millions of years of sunlight.
I'm working on getting the numbers, but you can do your own math---and scare yourself silly---as I have.
"I would rather discover a single fact, even a small one, than debate the great issues at length without discovering anything at all."--- Galileo Galilei, c. 1640
-- (Hallyx@aol.com), March 06, 2000.
...then an astonishing thing happened. Bubbles began rising in the liter-size bottle of algae, which looked a little like green tea. "We were saying, 'God, what is this coming out?'" Melis said. "'Is it oxygen? No. Where would it come from? There is no oxygen activity anymore.'"
A couple of milligrams of Beano might have solved the problem.
-- I'm Here, I'm There (I'm Everywhere@so.beware), March 06, 2000.