`Cleaner air' bus hits UBC roads for test runs

The 1981 GMC bus parked behind UBC's Dept. of Mechanical Engineering looks, sounds and performs like a regular diesel-powered transit coach with three notable exceptions.

Powered by a unique natural gas injection system, the vehicle emits half the pollutants and costs close to half as much to fuel as its gas-guzzling counterparts. And then there's the paint job.

"She's a beauty," remarks Brad Douville, admiring the blue sky side panels dotted with clouds.

Douville, 27, is chief engineer for Westport Innovations Inc., a UBC spin-off company with big plans for its revolutionary technology called High Pressure Direct (HPD) Injection. He believes the research breakthrough could save the diesel engine from extinction.

Prof. Philip Hill, with UBC's Dept. of Mechanical Engineering, has been developing HPD injection technology with Douville and others in his lab since 1989. Six of his former students have moved into full-time jobs at Westport headquarters located a five-minute walk from Hill's lab.

"I didn't foresee this arrangement when I started but I certainly have no complaints," says Hill, whose research was initially funded by the B.C. Science Council. "The teamwork to date has been fantastic."

Hill's technology, licensed to Westport in 1994 through the UBC's Industry Liaison Office, is not the first attempt to adapt a diesel engine to natural gas. What sets the HPD system apart from other natural gas conversions is that it drastically reduces harmful emissions of both nitrogen oxides and tiny soot particulates without compromising a diesel engine's efficiency or performance.

The U.S. Environmental Protection Agency (EPA) signed an agreement with manufacturers in 1995 to cut emissions from heavy-duty trucks and buses in half starting in 2004. Westport President David Demers says the Westport technology gives manufacturers a low-cost method of meeting terms of the agreement by bringing emissions of nitrogen oxides and particulates below 1998 EPA levels.

The conversion to HPD injection is done without expensive modifications to the engine and power train. The retrofit requires replacing the diesel fuel injectors, adding a natural gas storage tank and a patented on-board gas compressor which maintains high injection pressure as tanks empty.

The secrets to Hill's research breakthrough are the compressor and UBC-designed injectors which have two tiny ports, one for natural gas and another for a jet of diesel fuel to ignite the gas as it is injected into the cylinder.

Diesel fuel in standard engines automatically ignites when it comes in contact with hot compressed air. Natural gas doesn't auto-ignite so the HPD injectors supply supplementary diesel fuel assistance. Other natural gas conversions, such as those in use by B.C. Transit, require a throttle and spark ignition which sharply reduces fuel economy.

Douville will be behind the wheel when Westport rolls out its first demonstration vehicle this month, a 16-year-old bus from the Los Angeles County Metro Transit Authority.

The bus's Detroit Diesel engine, retrofitted with the HPD injection system, will undergo tests for two months in and around UBC before being shipped to California for formal trials.