CHICAGO HEIGHTS | Remember when a gallon of fuel cost less than a buck?

Students at Bloom High School do.

Advanced Placement chemistry students will take part in a project funded by a $10,000 grant to convert vehicles at the school from running on diesel to biodiesel fuel costing 89 cents a gallon to produce.

BP Americas Inc. gave the grant to chemistry teacher Barry Latham to refit the trucks to run on biodiesel brewed from the cafeteria cooking oil.

"I can make a 30-gallon batch in 24 hours," he said. "Last year, we made almost 1,000 gallons."

Specifically, the grant will pay for the diesel vehicles to get new filters and be refitted with synthetic rubber hosing because, as a strong solvent, biodiesel dissolves natural rubber.

"This will save the district on fuel costs," Latham said, adding that the process eliminates almost all waste. "Nothing produced goes in a landfill or is poured down the drain."

And the students? Well the students will be the chemists behind the project, testing chemicals, alcohols and catalysts then measuring the purity of the final product to ensure the biodiesel really is biodiesel.

The conversion occurs in the school greenhouse, where a set of connected containers, filters, timers, pipes, switches and heaters comprise the system that turns used french fry cooking oil into the yellowish liquid biodiesel.

"Hearing him explain it all, now I'm excited about it," said Cathy Hopkins, of Glenwood, an incoming senior in Latham's class. She and twin brother David will spend part of the summer working on labs and independent research projects studying biofuels. Hopkins, who has an interest in science and math, hopes work in the lab next year will help her decide a career path.

"You can run your diesel car on 100 percent biodiesel," Latham said.

He recommends a blend of diesel and biodiesel to acclimate your car to the different fuel. Biodiesel works best in warm temperatures because it starts to thicken at less than 50 degrees and freezes at 32, he said.

But the benefits of biodiesel outweigh the cold weather concerns and go far beyond the low costs of making the fuel.

"A change from diesel to biodiesel results in 75 percent less emissions," Latham said.

The engines also run smoother and quieter because of the fuel, he said.

Latham demonstrated a more subtle perk of biodiesel by kneeling and smelling the exhaust coming from his old Mercedes turbodiesel in the school parking lot: "It smells like french fries."