Avocado Oil, Taco Grease Fuel Eco-Bus in Mexico
MEXICO CITY Ecologists toured Mexico City taco stands and sushi bars Wednesday to refuel an old school bus with waste cooking oil that will power the next leg of a green-awareness tour from California to Costa Rica.
The bus, which ran on avocado oil during a week-long drive down from the U.S. border, is being used to prove that vehicles can run on recycled fuels that pollute less than gasoline as it chugs around oil refineries, factories and eateries collecting vegetable oil.
"We're running low, we have to score some oil today," said environmentalist Zak Zaidman as crew members called around the greasiest-sounding eateries in the city's phone directory.
"We have two Japanese restaurants that have lined up a gallon or two and we are trying some taco stands. And we hope to hear back from a restaurant where we had dinner last night."
The eye-catching 1974 white American bus is loaded with tanks that can carry 350 gallons of oil. Its diesel engine has been modified to run on the more viscous food oil.
Headed for Guatemala, El Salvador, Honduras, Nicaragua and lastly Costa Rica, it left San Francisco Dec. 1 with 150 gallons of waste oil from local Chinese and taco restaurants.
It next filled up with used frying oil -- still hot -- from a Mexican restaurant in Tucson, Arizona, and a load of avocado oil from a refinery across the border in Sonora, Mexico.
"We are probably down to about 75 gallons so it would be good to score a lot. If we can't get it all at once we'll just get it little by little. We can just go to a restaurant, see what's in their grease trap, and pick it up," Zaidman said.
Waste Oil Everywhere
Vegetable oil is carbon-neutral, meaning when burned it releases the same amount of carbon as the plant it came from sucked in during its life, unlike much dirtier fossil fuels.
"Oil is a nonrenewable resource and our atmosphere is a finite container for our pollution," Zaidman said.
"When you look at all the waste oil thrown away by restaurants and companies that fry chips and stuff, there's tons that could be salvaged."
Crops like soybeans can also be grown for biofuels -- seen as a transitional energy source that Zaidman said could cover 10 percent of fuel needs, including for things like industry and tractors, for 30 to 40 years. "What with pollution and wars over oil, a lot of people want to get off petroleum," he said.
His group, who notes the diesel engine was actually invented to run on peanut oil, hopes to take its Sustainable Solutions Caravan tour, now in its second year, to Europe in 2005.
The bus uses biodiesel, a nontoxic fuel made from vegetable oil, alcohol and lye, to start off its engine until it is hot enough to heat up the food oil and reduce its viscosity.
A trickle of green-minded U.S. car users is going to pumping stations for biodiesel, which works with a normal engine but emits exhaust fumes that smell like fried food.
To convert a diesel engine to run on food oil costs around $400, a much cheaper option than fuel cell cars on the market.
Zaidman said there is no effect on engine efficiency.