SCHOOL bus maker counting on new technology to cut tailpipe emissions

Wednesday, June 6th 2001, 12:00 am

By: News On 6

TULSA, Okla. (AP) _ A white handkerchief emerging spotless from a diesel engine tailpipe may mean International Truck and Engine Corp. won't be waving a white flag in the war between alternative fuels.

International, a division of Chicago-based Navistar International, showed off its new ``green diesel technology'' Tuesday as it unveiled its new $45 million, 400-worker school bus plant in Tulsa.

Regional sales manager Bill Cheever stuffed a white handkerchief in the tailpipe of a diesel-powered bus equipped with a device to filter emissions that contribute to smog.

Once removed, the cloth had no visible traces of black soot, commonly seen belching from buses, truck tractors and other diesel-burning vehicles. The bus tailpipe appeared to expel only warm air instead of the smoky stench of diesel exhaust.

The technology, dependent on new diesel fuel with lower amounts of sulfur, already meets stringent emission standards that become effective in 2007.

New technological success is imperative for International, among the world's largest diesel engine manufacturers for buses and mid-sized trucks that include dump trucks and delivery vehicles. Sales were $8.5 billion last year.

The company manufactures 60 percent of all school bus chassis and is warring for market share against engines that burn compressed natural gas and other fuels as tighter emission standards loom.

``We always want to lead. We don't want to follow anybody,'' said John Horne, International's chairman.

The U.S. Environmental Protection Agency is mandating cleaner exhaust and fuels to reduce tailpipe emissions by the equivalent of 164 million cars. By model year 2007, heavy-duty trucks and buses are to cut emissions by 95 percent.

Diesel engines were dealt a setback in April when air quality officials in Southern California voted to require school-bus operators in the Los Angeles area to buy other alternative fuel vehicles.

But International officials said green diesel technology will eventually win out because of what they tout as superior fuel and engine performance.

The EPA and the California Air Resources Board's recently certified International's technology for use in school buses.

New regulations call for lower levels of nitrogen oxide, soot and particulates in smog, which contributes to asthma and other respiratory ailments.

To cut emissions, International engineers lowered the engine timing to reduce nitrogen oxide in the exhaust. But lower timing increases the amounts of particulates, which include soot and tiny oil vapors in the exhaust.

A device called a continuous regenerative trap, which works like a catalytic converter and a muffler, removes the particulates. The system is dependent on new diesel fuel with substantially lower amounts of sulfur, which inhibits the trap.

Sulfur in highway diesel is to be cut from 500 parts per million to 15 parts per million in 2006.

``This fuel will be required to get the maximum out of technology like this,'' Cheever said.

The green diesel technology coupled with low-sulfur diesel resulted in 50 percent less particulates than natural gas powered vehicles. The engine also has lower emissions of nitrogen oxide and hydrocarbons, Cheever said.

But the technology adds about $7,000 to the price of a school bus and some districts currently don't want to pay the extra money until they are required to do so.

Compressed natural gas can add $35,000 to the price of a large $85,000 bus, said Tom Cellitti, vice president and general manager for International's bus division. A regular sized school bus in Oklahoma normally costs about $50,000, he said.

Beginning in August, new flat-nosed school buses made in Tulsa will have engines equipped with the technology. The buses will be bound mostly for California and Arizona, Cellitti said. Eventually, all buses at the plant will have the engines and exhaust systems, he said.