Nitrogen diesel catalysts

Table 28. Emission of carbon monoxide, gaseous hydrocarbons, nitrogen oxides and particulate matter from a passenger car equipped with an IDI/NA diesel engine, and conversion over a diesel catalyst in the fresh and the engine aged state, in the different phases of the US-FTP 75 vehicle test procedure and of the European MVEG-A vehicle test procedure. ...

Compliance with the EuroIII standards (2000) forced the fitting of Diesel oxidation catalysts (DOC) in the exhaust line [for the after-treatment of unburnt hydrocarbons (HC) and carbon monoxide (CO)]. Additionally, the exhaust gas recirculation (EGR) was adapted to reduce the engine-out emissions of nitrogen oxides (NOx). 

Catalyst activities, specific, 10 47t Catalyst additives, nitrogen oxide emissions and, 11 719 Catalyst-based diesel particulate filter (CB-DPF) technology, 10 61-62 Catalyst bed(s)... 

NO control, diesel engine, 10 61. See also Nitrogen oxide (NO ) exhaust control NO emissions, 10 32, 35, 36, 46, 137 NO production, 13 855, 856-857 NO reduction catalysts, 12 430 NO reduction technology, post regenerator, 11 719-720 NOXSO process, 22 779 Nozzle disk centrifuge... 

A lean NOx trap (LNT) (or NOx adsorber) is similar to a three-way catalyst. However, part of the catalyst contains some sorbent components which can store NOx. Unlike catalysts, which involve continuous conversion, a trap stores NO and (primarily) N02 under lean exhaust conditions and releases and catalytically reduces them to nitrogen under rich conditions. The shift from lean to rich combustion, and vice versa, is achieved by a dedicated fuel control strategy. Typical sorbents include barium and rare earth metals (e.g. yttrium). An LNT does not require a separate reagent (urea) for NOx reduction and hence has an advantage over SCR. However, the urea infrastructure has now developed in Europe and USA, and SCR has become the system of choice for diesel vehicles because of its easier control and better long-term performance compared with LNT. NOx adsorbers have, however, found application in GDI engines where lower NOx-reduction efficiencies are required, and the switch between the lean and rich modes for regeneration is easier to achieve. 

The cobalt molybdate catalyst is also suitable for the reduction of organic nitrogen bases (30). From Colorado-shale-oil fractions containing 2% N2 and 0.7% sulfur, jet and Diesel fuels have been obtained with 0.01 to 0.1% N2 and 0.03 to 0.04% sulfur. 

SINOx [Siemens NO system] A process for removing nitrogen oxides and dioxins from the exhausts of stationary diesel engines and truck engines, based on the SCR process. The catalyst is based on titania and is in the form of a honeycomb. The reducing agent is ammonia, generated from an aqueous solution of urea. See SCR. 

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