Advanced exhaust gas treatment concepts

One of the objectives of the project is to develop and demonstrate advanced aftertreatment technologies. In the first year of the project the main activity has been to develop new advanced catalyst formulations (DOC, NSC, and SCR/SCRF) and to supply the selected solutions for the demonstration vehicles.

The main challenges in all cases were to extend the activity windows of the catalysts, to ensure that they are effective under the most challenging RDE conditions, in particular those linked to city driving. In addition to catalyst components, Johnson Matthey supplied synthetic test rig catalyst characterization data to Ricardo to enable aftertreatment modelling to be performed over various Real Driving Emissions (RDE) drive cycle scenarios. A complete engine and vehicle simulations have been performed considering different aftertreatment systems. For each demonstrator vehicle (WP2, WP5 and WP6), a mainstream and a backup aftertreatment solutions have been proposed.

At CRF the aftertreatment technologies have been integrated on a demo vehicle and the experimental data have been shared within the partners to drive component development and the simulations activities. One of the main key issue is clearly the low exhaust temperature in heavy urban conditions that could heavily reduce the aftertreatment NOx reduction efficiency. In those conditions a thermal management strategy is needed and a deterioration on fuel consumption needs to be taken into account.

Various exhaust thermal management strategies have been simulated in Ricardo to understand the effect on emissions control and fuel consumption. Moreover an experimental campaign has been realized using a Fiat 1,6L diesel engine to assess the performances of an exhaust variable valve timing.

In parallel Chalmers is developing a detailed SCRF simulation based on laboratory experimental testing, where the effect of soot on the ammonia oxidation and standard SCR reactions was studied and also the effect of gas composition on the soot regeneration was examined.