Study on Emission Reducing Method with New Lean NOX Catalyst for Diesel Engines

Katsuji Wada; Norio Suzuki; Naohiro Satoh; Tomoko Morita; Satoshi Yamaguchi; Hiroshi Ohno

doi:10.4271/2007-01-1933

2007-07-23

Study on Emission Reducing Method with New Lean NOX Catalyst for Diesel Engines 2007-01-1933

In recent years, emission regulations have become more stringent as a result of increased environmental awareness in each region of the world. For diesel engines, reducing NO_X emissions is a difficult technical challenge.[1],[2],[3],[4].

To respond to these strict regulations, an exhaust gas aftertreatment system was developed, featuring a lean NO_X catalyst (LNC) that uses a new chemical reaction mechanism to reduce NO_X.

The feature of the new LNC is the way it reduces NO_X through an NH₃-selective catalytic reduction (SCR), in which NO_X adsorbed in the lean mixture condition is converted to NH₃ in the rich mixture condition and reduced in the following lean mixture condition. Thus, the new system allows the effective reduction of NO_X. However, in order to realize cleaner emission gases, precise engine control in response to the state of the exhaust aftertreatment system is essential. This control includes maintaining the LNC activation state and reducing NO_X emissions before LNC activation.

In this study, effective NO_X reduction technology was developed by combining controls, such as that for maintaining LNC activation temperature, with studies of engine emission improvements and techniques to supply reductant to the catalyst.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Digital $37.00 Print $37.00

Preview Document

We also recommend:

Standards

SAE Mobilus®

Publications

News

Events

Professional Development

A World in Motion (PreK-12)

Participate with SAE

SAE Membership

Donate

Study on Emission Reducing Method with New Lean NOX Catalyst for Diesel Engines 2007-01-1933

SAE MOBILUS