Diesel engines hold a lot of promise, especially the ones in use over in Europe. They make more torque than their petrol cousins, usually come equipped with turbochargers, and tend to emit fewer emissions in low-sulfur form.
Researchers at a lab in Munich, Germany, have built a turbocharged diesel engine that they hope will emit less than 5 milligrams of soot and 80 milligrams of nitrogen per kilometer without resorting to a catalytic converter. Lofty goals, but they are making good headway.
Under development by researchers at Technische Universitaet Muenchen (TMU), the diesel engine uses a variety of high tech solutions as well as precision measuring instruments to figure out exactly how soot forms. The engine is being developed to meet ever more stringent European emissions standards. The Euro 6 standards, set to go into effect in 2014, allows for just 5 milligrams of soot and 80 milligrams of nitrogen per kilometer.
That is half the emissions currently allowed under Euro 5 standards. The TMU researchers have taken it a step further by denying themselves the luxury of using a catalytic converter, which captures many of the engine emissions before going into the air. How? Technology.
For example, a high-pressure injector atomizes fuel down to miniscule rivulets, allowing them to be completely burned in the combustion chamber and thus minimizing the amount of unburned fuel allowed into the atmosphere. A high-compression turbocharger compresses the air to ten atmospheric pressures, twice what most cars use. This pushes enough oxygen into the combustion chamber to ensure a complete burn of the fuel.
They also developed a microscopic method of measuring exactly what happens in a combustion chamber to figure out how soot forms. As it turns out, the unburned fuel in the combustion chamber becomes enveloped in exhaust gases, building layer upon layer on the piston, valves, and other places, thus reducing fuel and emission efficiency over the life of the vehicle.
Cool stuff, and being able to eliminate catalytic converters would shave a few bucks off the price of new cars for sure (plus, thieves might stop stealing them for the rare metals inside).
Source: Eureka Alert | Image: Sebastian Pflaum