Study: Sunflowers Could Supply Hydrogen Fuel

One of these days you might find yourself tooling down the highway in a car that runs on flower power.

Or maybe not.

But at least that's the goal of British researchers who say they have come up with a way to extract hydrogen from sunflower oil — the same stuff you might put on your salad — which in turn could be used as the fuel of the future, powering everything from our cars to our cell phones.

Hydrogen holds great promise as a clean-burning fuel that could free us forever from fossil fuels. But it has been hyped so much recently that it is often seen as the answer to all our energy problems so we don't need to worry about potentially catastrophic global oil shortages.

Don't bet on it.

There are nightmares associated with the acquisition and distribution of hydrogen that could kill this dream in its infancy. Despite the fact that hydrogen is found just about everywhere, it doesn't travel alone. And separating it from other elements, such as oxygen, requires processes that also use energy.

And where does that energy normally come from? It is produced by burning fossil fuels — the stuff we're trying to get away from — in processes that use more energy than the extracted hydrogen is likely to produce. That's called a net energy loser, and until someone solves that problem hydrogen power isn't going to go anywhere.

What If …

Yet, there is a glimmer of hope. Researchers around the globe are fine tuning a "breakthrough," if we dare use that overworked word, that came out of Japan a quarter of a century ago. It just may be possible to get all the hydrogen we need by using ordinary sunlight to drive something called "artificial photosynthesis."

Kenichi Honda and Akira Fujishima were researching photochemical processes at the University of Tokyo in the late 1960s when they made a remarkable discovery. They hooked an electrode coated with titanium dioxide to another electrode coated with platinum and exposed it to sunlight.

In a process that is similar to photosynthesis, by which living cells use sunlight to grow, the researchers were able to split water into its two components, hydrogen and oxygen. Honda and Fujishima announced their findings in what has been called a "milestone paper" in 1971, for which they recently received the 2004 Japan Prize for their pioneering work.

Ever since then scientists and engineers around the world have been trying to build upon that early research and create machines that can carry out artificial photosynthesis and produce hydrogen efficiently enough to make it worth the effort. If we're going to switch to a hydrogen economy we're going to need lots of the stuff, and we can't pave the planet with solar collectors to get it.

It seems to be one of those situations where all the right pieces are there, but putting them together has been a real challenge.

Titanium dioxide, for example, is readily available. It's probably in the toothpaste you used this morning. It's found in beach sand, and certain rocks, and it's widely used as a whitening agent in everything from paint to cosmetics.

And of course there's no shortage of water. So all you need is sunshine, and where can you find a lot of that? How about Australia?

That thought occurred to two professors at the University of New South Wales in Sydney, who have been tinkering with artificial photosynthesis for years, and they claimed recently to be on the brink of success. Janusz Nowotny and Chris Sorrell told an international conference in Sydney last month that they expect to be extracting hydrogen from water on a large scale within seven years.

"Based on our research results, we know we are on the right track," Nowotny said in a press release issued prior to the conference.

"We have abundant sunlight, huge reserves of titanium and we're close to the burgeoning energy markets of the Asia-Pacific region," Sorrell added. But, he said, the same technology could be used anywhere.

So, success is at hand, right?

Maybe, but maybe not.

Stumbling Blocks

Others have made similar claims, leading to disputes that at times have been vitriolic.

Chemists at Duquesne University in Pittsburgh announced two years ago in a paper published in the journal Science that they had achieved an efficiency of 8.35 percent in the conversion of solar energy to hydrogen extraction. That's considerably higher than most other claims.

But they came under immediate attack, with one critic claiming their "remarkable achievement" was meaningless because they had used electricity, not just solar power, in their experiments. Even the Japanese researchers jumped on them for not citing their earlier work.

All of that reveals the importance of this research. The stakes are enormous, and the rewards could be astronomical, if this idea ever moves from the lab to the factory.

In the meantime, there's that bit about sunflowers.

Valerie Dupont, an energy engineer with the University of Leeds in England, told the national meeting of the American Chemical Society last month that she and her colleagues have developed a "hydrogen generator" that pulls hydrogen out of sunflower oil using only air and water vapor and two catalysts, one nickel-based and the other carbon-based.

Dupont reported that the generator produces hydrogen that is 90 percent pure, which she says is better than most other methods. But it also produced carbon dioxide and methane, two greenhouse gases.

And even if it works perfectly, there's still that old problem of scale. How many sunflowers would have to be sacrificed just to fuel those English cabs zipping around London?

Lee Dye’s column appears weekly on A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.