Page 22 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

Introduction 5

European standards to be met in years 2000 and 2005 respectively (see also European directive
9411 2/EEC). The last four columns correspond to the current USA Federal emission standards
(1996), to the Californian TLEV (1996-1998+), LEV (2000) and ULEV (2005) emission
standards.

US drimg cycle
SS EU driving cycle
1.4

1.2

1.0

0.8

0.6

0.4
spec&
0.2 onsumption
www
0

rotational speed @I’M)

Fig. 3 (from [34], p. 162)

As Table 1 shows, in some respects the draft 2005 European regulations are more severe than
the Californian ULEV standards, which until now have been seen as very close to the limit of
what is technically feasible for the internal combustion engine. The proposed European 2005
limit of 0.25 g/km NO, for light duty diesel engines is completely beyond the diesel’s
technology reach unless one key technology, the NO, reduction catalytic converter, can be
brought to full effectiveness and to production in the meantime. It must be borne in mind that
the driving cycles of EC2005 and ULEV involved differ significantly (see [6] and [7]). For the
TLEV, LEV and ULEV standards the HC is measured as non-methane organic gases
(NMOG).