Air Products & Chemicals Inc. opened Pennsylvania's first hydrogen-filling station near Beaver Stadium on the Pennsylvania State University main campus this month.

The experimental station - one of 53 nationwide, according to the National Hydrogen Association - cost $10.5 million and is part of a national effort to break what some politicians call the nation's addiction to foreign oil by developing hydrogen-powered fuel-cell vehicles.

Fuel cells function like batteries by converting hydrogen and air into electricity, and Air Products, one of the world's largest producers of hydrogen for industry, is aiming to play a big role if the technology takes off.

"It's clear to us that the hydrogen economy will ultimately happen. It's not a question of if it will happen, but when," said Ed Kiczek, senior business development manager for future energy solutions at Air Products, which has 50 employees in the Allentown area devoted to hydrogen-fuel projects.

President Bush has called hydrogen a viable alternative to petroleum, and his administration has tagged $1.2 billion for hydrogen-fuel-cell development over several years.

The Air Products station in State College is partly financed by the Department of Energy. Another chemical company, Philadelphia's Arkema Inc., has received two separate grants worth a total of $12.1 million from the federal agency to adapt its Kynar polymer for fuel-cell membranes. About a dozen researchers work on the project in King of Prussia.

Fuel-cell membranes are extremely thin - one-thousandth of an inch - and stacked like a deck of cards. Hydrogen is fed to the special membranes, releasing hydrogen electrons in an electro-chemical reaction. The hydrogen electrons are then fed to an electric circuit for power. The byproduct of the reaction is mixed with oxygen to form water for emissions. "We feel that we are probably on the right track," said Michel Foure, the director of research and development, who leads Arkema's fuel-cell program.

With India and China putting added burdens on the world's petroleum reserves, "there is no way that any economy can rely on oil" for the long haul, said Yury Gogotsi, a professor of material science and engineering at Drexel University.

Hydrogen is one alternative energy source for vehicles. The others are ethanol, solar and electricity, Gogotsi said. Corn-based ethanol is popular. But experts doubt that farmers can produce sufficient corn to feed people and livestock and to fuel the economy. Hydrogen can be obtained from bountiful sources, including coal and water, and the exhaust from a pure-hydrogen vehicle is water.

Researchers and political leaders have several economic and technical obstacles to overcome before commuters will zip around in fuel-cell cars, Gogotsi said. The nation has to replace gasoline stations with those peddling hydrogen; fuel cells have to be improved; reliable hydrogen sources have to be developed; and scientists need to invent ways to store more hydrogen in vehicles to avoid repeated fueling stops.

In State College, Air Products and Penn State are experimenting with a fuel blend of 30 percent hydrogen and 70 percent natural gas. The blend is burned in specially adapted internal-combustion engines. It is considered an intermediate step to 100 percent hydrogen vehicles.

"We're still working out the wrinkles," said Hugh Mose, general manager for the 125-employee Centre Area Transportation Authority. The authority is lending one of its 52 buses to the project.

"If you don't get the blend just right, you'll lose power, or you won't get the benefit of reduced emissions," Mose said. Soon the bus will be loaded with sandbags to simulate the weight of passengers on the road.

Air Products - which had $8.1 billion in sales in 2005 - says it does not intend to enter the retail market with company-branded hydrogen-filling stations, but is selling its technology and equipment to others.

Oil giant BP P.L.C. used Air Products equipment in a hydrogen-filling station in Beijing, which will fuel transit buses for the 2008 Olympics. Air Products also supplied BP with technology for hydrogen stations in Detroit and California.

With the stations, Air Products is shrinking its huge industrial hydrogen reformers - usually built near oil refineries in the Gulf Coast and California - to something that can fit on a lot the size of a gas station. The initial goal is modest. The State College station will produce the hydrogen equivalent of 100 gallons of gasoline a day.

"The scientific community is in agreement that hydrogen has a lot of potential," said Joel A. Anstrom, director of Hybrid and Hydrogen Research Center at Penn State. "The question is bringing the cost down to make it viable."