In Search of the Biodiesel Hybrid Holy Grail

While diesel engine designs have advanced rapidly, allowing more efficient and relatively less polluting diesel vehicles of all types, Europe has waited until now to taste the bitter fruit of their generation-old love of dirty diesels. From a recent report in The Irish Times: "German motorists are facing drastic driving restrictions in all major cities as a result of new EU clean air legislation. But their counterparts in Ireland will be able to drive on because Irish cities have not yet breached the limits". Across Europe, this issue is causing a serious row.From the IT again: "The tough new limits, in place since January 1st, mean that city air may not contain more than 50 micrograms of fine particle dust per cubic metre. The dust particles, known as PM10s, are most commonly released from diesel engines. Cities are allowed to breach the limit on no more than 35 days a year. Munich and Stuttgart are already above it, and environmental activists have started legal battles to force them to take action. D'sseldorf, Frankfurt and Berlin are close behind".

While diesel cars on every continent have always been cheaper to drive then plain gasoline ones, they've also had the drawback of relatively higher emission rate per mile driven for acid forming gases and seriously health-threatening particulate matter. This is particularly important in Europe, where a very large portion of the auto and truck fleet is diesel and where retrofit improvements would be very expensive: hence recent proposals to meet the health standards by limiting city driving times.

emissions from diesel engines over time.JPG
The USEPA has been collaborating with the industry for years to produce a "negotiated rule making" on what the new diesel technology standards should be,and when they come into effect. USEPA and refiners also are working to lower the sulfer content of US-sold diesel fuel, a prerequisite for the new diesel engines to function right. For the recently improved diesels, designs will include exhaust filters to catch the nasty little particles. The really good news, TreeHuggers, is that designers are working toward diesel engines that emit less particles, sans filters.

Put it all together and incorporate it into a diesel/electric hybrid and you have the recipe for a bio-diesel hybrid car with phenomenal efficiency, low cost to operate, reduced acid gas emissions, and elimination of the particulate risk.

According to a trade journal, DaimlerChrysler's future diesel hybrids will be based on the hybrid technology being developed with GM and would be available in late 2007 or early 2008. Given the pollution problem now surfacing in the EU and the higher cost of diesel there, the first diesel hybrids could well appear there. For now, we'll have to be satisfied with looking at concept cars like the Opel Astra diesel hybrid pictured at the front of this post or at a military prototype.

by: John Laumer