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It is easier and more economical to conduct R49 13-mode cycle emission tests in engine test bed compared to chassis dynamometer ECE R83 test. This is because of costlier test equipment for chassis dynamometer and requirement of separate dynamometers for various categories of vehicles, even when connected with the same engine. Two methods have been attempted for predicting ECE R 83 cycle emissions from R49 test results based on the extensive emission trials conducted in both engine and chassis dynamometers. The first method is by using the modified weightage factors applied to each mode results of R49 test. While the second method uses the mapped ECE R 83 load/speed points for a particular configuration of vehicle and translating them to nearest load/speed point of R49 cycle. The predicted emission values conform well to the actual chassis dynamometer results.

Three catalysts such as Cu-X, Cu-Ni-X, and Cu-Fe-X based on X-Zeolite have been developed by exchanging its Na+ with copper, Iron and Nickel metal ions and tested in a commercial Maruti 800 cc S I engine and some encouraging results for reduction of NOx and CO have been obtained. The bi-metal catalysts are named based on the order of ion-exchange treatment. Out of three catalysts, Cu-X catalyst exhibits the best NOx and CO conversion performance while Cu-Ni-X shows better performance compared to Cu-Fe-X catalysts at any catalyst temperature. Maximum NOx and CO conversion efficiencies achieved with Cu-X catalyst are 62.2% and 62.4%, with Cu-Ni-X catalyst are 47.0% and 50.0%, and with Cu-Fe-X are 43.1% and 43.8% respectively. Unlike noble metals, the doped X-Zeolite catalysts studied here, exhibit significant NOx reduction for a wide range of A/F ratio and exhibit a slow rate of decrease with increase in A/F ratio.

Copper ion-exchanged X-zeolite with urea infusion was tested for nitrogen oxide (NOx)conversion efficiency in this study. Temperature datapoints were obtained to arrive at peak activation temperatures. Variation of the air/fuel ratio showed the widening of the λ-window(the range of air-fuel ratios over which the NOx conversion efficiency is considerable); a maximum of 62% NOx conversion efficiency was obtained in the lean-burn range. Effects of space velocity variations were also observed. In order to minimise the deactivation of zeolite caused by water, ammonium carbonate and ammonium sulphate were deposited on the copper ion-exchanged X-zeolite and the corresponding NOx conversion efficiencies measured. Ammonia slip (leakage of unreacted ammonia), a prospective pollution hazard, was observed to be more in case of urea infusion than ammonium salt deposition at higher temperatures.

Three catalysts based on X-zeolite have been developed by exchanging its Na+ ion with Copper, Nickel and Vanadium metal ions and tested in a stationary SI engine exhaust to observe their potentialities for NOx and CO controlling. The catalyst Cu-X, in comparison to Ni-X and V-X, exhibits much better NOx and CO reduction performance at any temperature. Maximum NOx conversion efficiencies achieved with Cu-X, Ni-X and V-X are 62.2%, 59.7% and 56.1% respectively. Unlike noble metals, the doped X-zeolite catalysts, studied here, maintain their peak NOx reduction performance through a wider range of A/F ratio. Back pressure developed across the catalyst bed is found to be well within the acceptable limits.