Tag - Emissions

CITA Webinar “Validation of a Method to Test NOx Emissions”


The webinar, hosted by CITA and the Joint Research Centre (JRC), took place on June 19th on the CITA Zoom channel with over 80 participants. The discussion focused on the collaborative project between the two organizations, aimed at validating a new method for testing nitrogen oxide (NOx) emissions during Periodic Technical Inspections (PTI) in the EU.

Mr. Jacopo Franzetti, Project Manager for Scientific Research at JRC – European Commission, and Mr. Max Holtermueller from DEKRA together with Mr. Thomas Ost, leader of the CITA Taskforce on Emissions, led the presentations. They highlighted the importance of NOx, its formation and reduction, and the scope, the method and results of the project.

Why Focus on NOx? Nitrogen oxides (NOx) are harmful pollutants with severe health impacts. NOx is a strong oxidizing agent that can cause respiratory issues, aggravate other pollutants' effects, and lead to diseases like asthma, bronchitis, and cardiovascular problems. A significant improvement in air quality in Europe has been noted, but NOx levels still exceed WHO guidelines, contributing to premature deaths. NOx primarily forms at high temperatures in the presence of sufficient oxygen, commonly occurring under high engine loads. This poses a challenge for PTI, as controlling these conditions during inspections is complex.

The Project. The JRC has developed a streamlined method for measuring NOx emissions during the PTI of modern Euro 6d diesel light-duty and Euro VI heavy-duty vehicles. This aims to identify malfunctions in Selective Catalytic Reduction (SCR) systems, crucial for reducing NOx emissions. The objective of the project was to validate a NOx monitoring method tailored for PTI in the EU, focusing on modern diesel vehicles under real-world conditions. Various CITA members participated, testing vehicles across different EU countries to account for diverse PTI systems.

The Results. 161 vehicles from various countries were tested, encompassing a wide range of mileages and ages. Key findings include:

  • Vehicle Age and Mileage:  A very wide range of vehicles were tested, with mileages ranging from 0 to 347.000 km.
  • NOx Emissions: Average NOx emissions were 26 ppm in the first 30 seconds, with significant variations among different participants and vehicle conditions.
  • Feedback: Participants rated the method's feasibility, integrability, and time effort on a scale from 1 to 5, with average scores indicating moderate satisfaction. Challenges included difficulty in warming up vehicles and software/hardware issues.

Conclusion. The validated method is suitable for modern diesel vehicles with SCR catalysts but not for those without. While the method is generally simple, integrating the warm-up process into PTI remains a challenge. Further optimization and precise specifications for the warm-up process are necessary. CITA's Task Force on Emissions is preparing a detailed report on the project's findings, expected to be published by August/September. Additionally, a survey on driving practices during PTI will be conducted between CITA members.

CITA remains committed to supporting the method's further development and implementation.