Abstract
It was investigated whether the urea SCR system has sufficient effect of NOx reduction or not under driving on the ordinary road. The driving test was conducted by putting the on-board FT-IR gas analyzer on the light-duty truck equipped with urea SCR system. Functional performance of that system was analyzed by continuous measurement data of the concentration of NOx, N2O, etc. and exhaust-gas temperature. As test results, it was revealed that the NOx reduction effect cannot be sufficiently exhibited if the SCR catalyst is not heated to the activation temperature, and phenomena enlarging the N2O emission during cold-start was found.
