VOA常速英语:New Process Uses Algae to Produce Alternative Fuel

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Researchers around the world are trying to find alternative fuels to replace fossil fuels, which are finite and might not be available in sufficient quantities in coming decades to meet the growing world demand for energy. In addition, burning fossil fuels produces carbon dioxide, which is linked to climate change. One U.S. company may have found a partial solution to both problems by using carbon dioxide to grow algae, which can be used to produce fuel.

On a 9.6-hectare tract of land on the Texas coast south of Houston, a start-up company from Florida called Algenol, in partnership with the Dow Chemical company, plans to build more than 3,000 bioreactors, starting next year. The bioreactors will grow algae that can produce ethanol fuel through a special process that involves using carbon dioxide from nearby coal-burning power plants to promote faster growth of the algae.

Algenol is already testing the process with 40 bioreactors in Florida, but the partnership with Dow and the U.S. Department of Energy on the Texas project is a major leap forward.

"There are very significant capabilities that Dow has that they are bringing to bear in this process," said Paul Woods, Algenol's Chief Executive Officer. "And I would say the same thing for the DOE [Department of Energy]. They will give us a financial ability to accelerate the process, to bring on more jobs, to have capabilities brought in from additional partners."

For Dow Chemical, the main focus will be producing material from algae that can be used to make plastics. The company currently uses natural gas for that purpose.

The Algenol bioreactors also produce oxygen as a byproduct and that can be fed into a power plant to burn coal more cleanly. Carbon dioxide produced by the power plant can be recycled back into the bioreactors to help promote more algae growth.

Once the site is developed, Paul Woods says the fuel it produces will be competitive with gasoline produced from petroleum at nearby refineries.

"We do not, in any way, intend to come to market with fuel that is more expensive than gasoline," he said. "We, in fact, intend to come to market with fuel that is less expensive than gasoline."

Some energy experts and environmentalists have expressed skepticism about the benefits of biofuels, especially ethanol produced from corn. But Woods notes that algae, using Algenol's patented process, produces eight times more energy than the energy used to make it. Corn-based ethanol produces only slightly more energy than it takes to produce it. And unlike corn, algae is not grown for food.

The Alegnol process involves the long-term growth of algae with continual extraction of the ethanol rather than cooking material to produce alcohol, which is the most common way ethanol is made from corn, sugar cane or waste material.

Many energy experts favor the development of electric vehicles rather than a heavy investment in biofuels. But Paul Woods says that idea is limited by the batteries used to store energy and that there is no battery currently available that can power long-haul trucks or heavy machinery.

"There will always be an advantage to a liquid transportation fuel. It has a lot more energy density than batteries," he said. "It will for a long time, at least while I am alive. And it is not just trucks and heavy machinery. It is even for an average family taking a longer trip than just a work commute, you really are going to have to have transportation fuel."

Biofuels are also favored by U.S. federal energy policies. The Energy Independence and Security Act of 2007 calls for increased use of biofuels in coming decades, with a goal of producing more than 136 billion liters of renewable fuels by the 2022.