Reducing emissions efficiently Bosch improves exhaust-gas treatment systems for commercial vehicles

· 2.2 cuts nitrogen-oxide emissions by up to 95 percent

· Maintenance-free Departronic 2 helps regenerate particulate filters

· Both available for 12- or 24-volt vehicle electrical systems

Bosch exhaust-gas treatment systems mean low emissions and higher efficiency for commercial vehicles – now and in the future. Denoxtronic, now improved and in its third generation, plays a major role in lowering nitrogen-oxide emissions and fuel consumption. Departronic, whose second and latest generation is maintenance-free, controls particulate-filter regeneration.

Denoxtronic: robust and versatile
Since emissions legislation was first introduced for commercial vehicles, nitrogen-oxide emissions have been reduced by 86 percent. The Denoxtronic 2.2 metering system developed by Bosch works together with an SCR (selective catalytic reduction) catalytic converter to lower nitrogen-oxide emissions by up to 95 percent. Using data from the engine electronics, such as the readings for engine speed and operating temperature, the Denoxtronic metering module injects just the right amount of AdBlue, a urea-water solution, into the exhaust gas flow. This gives rise to ammonia, which reacts with the nitrogen oxides in the SCR catalytic converter to produce non-toxic nitrogen and water. When SCR exhaust-gas treatment is used, CO2 emissions and fuel consumption can be lowered by roughly 3 percent. This cuts operating costs, and is one reason for the continuing rise in popularity of SCR exhaust-gas treatment for commercial vehicles, especially with emissions standards becoming stricter worldwide in the future. Continuous improvements have been made to Denoxtronic since the first generation went into series production in 2004. The second Denoxtronic generation, launched in 2006, injects such finely atomized AdBlue into the exhaust upstream of the SCR catalytic converter that there is no need for to use compressed air for metering. The current, third generation is available for both 12- and 24-volt vehicle electrical systems. Where the delivery module used to be warmed by electric heaters, the third generation of Denoxtronic offers an alternative: the module can be attached to the engine cooling circuit to utilize the heat it gives off. The robust system has a long service life and, thanks to its modular construction, can be integrated flexibly and easily into many different vehicle models. The electronic control system for Denoxtronic can be integrated either into the engine control unit or into a separate metering control unit, depending on which option customers prefer.

Departronic for particulate-filter regeneration
Bosch Departronic has been in the market since 2006. This diesel-metering system regenerates particulate filters in medium and heavy commercial vehicles. It injects a precisely metered quantity of diesel into the exhaust flow, upstream of the oxidation catalyst. As this fuel burns, exhaust temperatures rise to roughly 600 degrees Celsius. This temperature increase causes the soot collected in the particulate filter to burn off. Compared with post-injection in the engine itself, Departronic is more economical: since the engine oil does not become diluted, it does not need to be changed nearly as often. The second Departronic generation has been improved in a variety of ways. It, too, can now be used with either a 12- or a 24-volt electrical system. Because Departronic can now handle a fuel supply pressure of 8 bar, diesel can be pumped into the system from the low-pressure circuit of the diesel injection system. Manufacturers of commercial vehicles can save money because an additional fuel pump is unnecessary. Departronic is self-cleaning and thus requires no maintenance. Its components are designed to withstand the harsh conditions to be found in commercial vehicles. The entire system has also been made lighter and more compact than the previous generation. Departronic will help commercial-vehicle manufacturers meet the emissions targets in the standards EPA 2007 and 2010, interim and final Tier 4, and Euro 6.

The Bosch Group is a leading global supplier of technology and services. In the areas of automotive and industrial technology, consumer goods, and building technology, some 275,000 associates generated sales of 38.2 billion euros in fiscal 2009. The Bosch Group comprises Robert Bosch GmbH and its more than 300 subsidiaries and regional companies in over 60 countries. If its sales and service partners are included, then Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for growth. Each year, Bosch spends more than 3.5 billion euros for research and development, and applies for some 3,800 patents worldwide. With all its products and services, Bosch enhances the quality of life by providing solutions which are both innovative and beneficial.

The company was set up in Stuttgart in 1886 by Robert Bosch (1861-1942) as “Workshop for Precision Mechanics and Electrical Engineering.” The special ownership structure of Robert Bosch GmbH guarantees the entrepreneurial freedom of the Bosch Group, making it possible for the company to plan over the long term and to undertake significant up-front investments in the safeguarding of its future. Ninety-two percent of the share capital of Robert Bosch GmbH is held by Robert Bosch Stiftung GmbH, a charitable foundation. The majority of voting rights are held by Robert Bosch Industrietreuhand KG, an industrial trust. The entrepreneurial ownership functions are carried out by the trust. The remaining shares are held by the Bosch family and by Robert Bosch GmbH.

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PI7053 – August 2010