水藻可煉生質油！ 科學家20年研究鹹魚翻身

The same slippery brown algae that covers streamside rocks, making footing hazardous for anglers, contains oil that can be turned into diesel fuel, says a Montana State University microbiologist.

Keith Cooksey is one of many U.S. scientists who studied the feasibility of turning algal oil into biodiesel in the 1980s.

From 1978 to 1995 a study to investigate algae as a source of fuel and its ability to consume the greenhouse gas carbon dioxide, CO2, was funded by the U.S. Department of Energy and administered by the National Renewable Energy Laboratory.

Twelve universities participated in the research program, which studied 3,000 strains of algae.

Cooksey specifically searched for thermophilic strains of algae isolated from hot springs. Cooksey's lab made a number of discoveries that were published in scientific journals. Funding dried up, however, and the scientists moved on.

"Rumor had it that big oil got in the way," Cooksey said. "They didn't want competition so the project was dropped."

Now, even big oil is interested in algae.

Chevron Corporation and the National Renewable Energy Laboratory announced in October that they have entered into a collaborative research and development agreement to produce liquid transportation fuels using algae.

Chevron and NREL scientists will collaborate to identify and develop algae strains that can be economically harvested and processed into finished transportation fuels such as jet fuel. Chevron Technology Ventures, a division of Chevron U.S.A. Inc., will fund the initiative.

"NREL operated the Aquatic Species Program for the Department of Energy for nearly 20 years, giving us unique insights into the research required to produce cost-effective fuels from algal oils or lipids. Our scientists have the advanced tools and the experience to rapidly increase the yield and productivity of key species of algae," said NREL Director Dan Arvizu.

"In Chevron we have found an ideal research partner with the skills and knowledge to transform these algal lipids to cost-competitive fuels and to distribute those fuels to consumers," he said.

As little as a year ago most of the energy sector was not aware of the potential of algae. But in the past few months Cooksey has been getting phone calls and e-mails from researchers and others who read about his work with algae on the Internet or had seen it referenced in scientific journals.

Companies tried to hire him as a consultant, and he was invited to attend conferences.

"It's a very strange feeling," said Cooksey, now 72. "You don't usually have people bending your ear on what you did 20 years ago. Science doesn't work that way, but in this case, it did."

Cooksey said his lab in the 1980s figured out how to increase oil production from algae. It developed a system that screened algae for their oil content. Cooksey’s lab developed a stain for algae, called Nile Red. When treated with the stain, the algae became fluorescent under certain conditions, making it easier to measure their oil content.

At the same time, algae technology provides a means for recycling waste carbon dioxide from fossil fuel combustion.

Algal biodiesel is one of the only avenues available for high-volume re-use of CO2 generated in power plants. It is a technology that marries the potential need for carbon disposal in the electric utility industry with the need for clean-burning alternatives to petroleum in the transportation sector.

The DOE program envisioned vast arrays of algae ponds covering acres of land located adjacent to power plants. The bubbling of flue gas from a power plant into these ponds would provide a system for recycling of waste CO2 from the burning of fossil fuels.

Algae grow naturally along rivers, the seashore, and in the mangrove swamps of southern Florida. They also grow in wastewater treatment ponds and can be grown commercially in excavated ponds.

Algae can be grown especially well in desert states that have plenty of sunshine and access to water unusable for traditional agriculture or drinking. Because of its salt content, salt water is more economical than fresh water for growing algae, so southwestern states with saline aquifers might find it easy to grow them.

It is possible to sequester as much as one billion tons of CO2 per year from algae farms in lands not useful for any other purpose in the Southwestern United States alone, the DOE program concluded.

Green Star Products, Inc. of San Diego, California announced in December that its algae-to-biodiesel program has attracted companies that need inexpensive CO2 sequestration.

"Algae eat CO2; convert it to oil, proteins, carbohydrates and other useful products; and, emit only oxygen to our atmosphere," says Green Star president Joseph LaStella.

"Algae farms are glutton eaters of CO2 gas and produce 100 times more oil per acre than traditional oil crops (such as soy oil), which can be converted to biodiesel," LaStella says.

Green Star has partnered with Biotech Research, Inc. to build a 100 acre commercial algae facility adjacent to an existing biodiesel plant and will use the CO2 emitted from the biodiesel plant's boilers to feed the algae, which will reduce global warming emissions.

The algae oil produced from the facility will be turned into biodiesel through the existing biodiesel plant facilities. The partners now are seeking funding and the right location.

LaStella said, "Algae were responsible for creating the Earth's oxygen atmosphere three billion years ago and it took around two billion years to form the modern atmosphere with 20 percent oxygen. Without algae we would not be here. We must ask our micro-size friends to again save us from ourselves."