Bosch reduces nitrogen oxide emissions

From 2014, new European Commission legislation will require a drastic reduction in nitrogen oxide (NOx) emissions in new passenger cars and light commercial vehicles. In addition, elevated nitrogen oxide levels in some European cities are causing concern. Bosch systems are already reducing nitrogen oxide emissions. The automotive supplier Bosch offers technical solutions for challenging standards such as Euro 6 – first and foremost, the Denoxtronic system for treating exhaust gas. “The more vehicles that are equipped with Denoxtronic, the sooner the nitrogen oxide situation will ease,” says Dr. Markus Heyn, president of the Bosch Diesel Systems division. “We’ve already taken the first step: there are already vehicles on the road that conform to the Euro 6 standard.” Bosch offers its system for both passenger cars and commercial vehicles. Both versions of the Denoxtronic system can reduce nitrogen oxide emissions by up to 95 percent. This is achieved by injecting liquid urea – also know as Adblue – into the exhaust gas flow. This reacts with the exhaust gas and turns nitrogen oxide into harmless steam and nitrogen.

For decades now, engineers at Bosch have been intensively studying the chemical process of combustion in order to develop solutions for reducing NOx emissions. The development of the diesel engine illustrates this. A odern diesel has around 96 percent lower raw emissions of nitrogen oxide than one produced in the early 1990s. This is also due to further developments in injection technology. “Nitrogen oxides are an invariable by-product of lean combustion – that is, when there is excess air in the combustion chamber. But less fresh air in the combustion chamber means more particulate matter. Optimizing combustion always has to move between these two poles,” says Jürgen Gerhardt, who is senior vice president for diesel engineering at Bosch.

Denoxtronic pays off through lower consumption
Optimized combustion alone is sufficient for compact-class passenger cars to satisfy the European Commission’s NOx emissions limit of 80 grams per kilometer, which will come into force in 2014. Large sedans, SUVs, and heavy commercial vehicles will only be able to achieve this with exhaust-gas treatment systems such as Bosch Denoxtronic. Although this will mean additional expense for vehicle buyers, lower fuel consumption can offset the higher cost. Overall, Denoxtronic helps to reduce fuel consumption by as much as 5 percent. It does this by enabling even leaner combustion, depending on the type of engine in which it is installed. The exhaust-gas treatment system thus practically pays for itself.

Bosch offers Denox solutions for all vehicle classes. In the compact class, these include engine-based technologies such as injection systems and NOx storage catalytic converters. For larger cars, Bosch offers the proven Denoxtronic 5, which is designed for system pressures ranging from 4.5 to 8.5 bar. Here as well, Bosch believes in the virtues of a compact design. Thanks to a supply module that can be integrated into the AdBlue tank, the Denoxtronic 5 is particularly suitable for use in compact commercial vehicles, SUVs, and sedans. For other commercial vehicles, Bosch offers Denoxtronic 6. The system is 4 percent smaller than previous versions. It thus saves valuable installation space and weight, and in addition can be produced more cost-effectively.