technology: Powering Trucks to Buses: This Spuds for You

Bill Siuru

What do you get when you cross a bunch of scientists with used French fry cooking oil? Gas, but not the smelly kind.

For instance, in Idaho - a state best known for its potatoes and French fry production - researchers have developed a biodiesel fuel produced from used French fry oil. This oil, combined with ethanol, called hydrogenated soy ethyl ester (HySEE), reportedly can be used in diesel engines with little or no modification, according to the Pacific Northwest and Alaska Regional (PN&A) Biomass Energy Program, the Idaho Department of Water Resources and the University of Idaho's Agricultural Engineering Department.

To prove this concept, PN&A recently began an "Over-the-Road" HySEE demonstration project that involves running a Kenworth tractor-trailer rig on a 50-50 blend of HySEE and regular diesel fuel. Following a three-day process, the J.R. Simplot Co., a French fry potato manufacturer, produces the HySEE in 500-gallon batches. It takes approximately 1.25 gallons of waste French fry cooking oil to create one gallon of biodiesel.

In addition, Simplot operates the Kenworth tractor-trailer, which is averaging 5.5 miles per gallon, at its plant in Caldwell, Idaho. Over a two- year period, Simplot will produce 20,000 gallons of biodiesel, and the Kenworth will cover 200,000 miles. After the demonstration, the rig's 435-horsepower Caterpillar 3406E engine will be disassembled to assess the impact of using the new fuel.

Several of PN&A's other programs involve American Indian tribes. For instance, Idaho's Nez Perce Tribe now is using biodiesel fuel in a Dodge pickup, a Ford pickup, a Suburban, a lawn mower and a garden tractor. The tribe has its own plant which makes fuel derived from used cooking oil from several area restaurants. Here methanol, rather than ethanol, is used because it is less sensitive to water.

Another interesting example of biodiesel testing is the "Truck-in-the-Park" demonstration. This project's goal is to reduce Yellow-stone Park's pollution by using biodiesel fuel in tour buses and park trucks.

Perhaps of greatest interest to park officials is that the biodiesel produces less visible smoke. Also, the exhaust has a nicer odor than its more conventional counterpart: Some say it smells like cooking French fries. However, the pleasant smell concerned park rangers who were afraid that it might attract Yellow-stone's bears.

So, to alleviate these concerns, the National Park Service conducted a study with 10 captive bears and concluded that the animals weren't attracted to the smell.

Researchers say that biodiesel fuels, either produced from vegetable oil or animal fat, are environmentally friendly. For instance, their gaseous emissions are less than with regular diesel fuel. In fact, since the ingredients in biodiesel are part of the natural cycle, they could lead to zero net gain of carbon monoxide and carbon dioxide emitted into the atmosphere.

Additionally, unlike fossil-based diesel, vegetable oils contain negligible sulfur levels, thus their combustion would not emit acid-rain-causing sulfur dioxide. Also, since the fuels are biodegradable, they break down quickly preventing long-term soil or water table damage.

Likewise, the HySEE fuel, in particular, can reduce the cost of producing biodiesel fuel by more than $1.40 a gallon since waste French fry oil costs 11 cents a pound versus about 30 cents for virgin vegetable oils, such as rapeseed oil (the more typical bio-diesel source), researchers say. Currently, at approximately $3 a gallon, cost is the main factor inhibiting biodiesel's widespread commercialization.

Doubtless, the impact of these studies will be far reaching, given that approximately 4 billion pounds of waste vegetable oil and animal fat are created in the United States annually.

The PN&A Regional Biomass Energy Program covers Alaska, Idaho, Montana, Oregon and Washington. For more information, contact PN&A, DOE Seattle Regional Support Office, 800 5th Ave., #3950, Seattle, Wash. 98104. (206) 553-2079.