New emissions regulation Euro 7: An opportunity to drive further innovation in emission control systems for ICE vehicles

The process for a new Euro 7 emissions regulations for cars, vans, trucks and buses is ongoing. It continues to consider the stringency and testing measures required to ensure that new vehicles make a real contribution to the EU’s zero-emission ambition by 2050. The Association for Emissions Control by Catalyst (AECC) is closely following the results of ongoing work and provides input from testing programmes that show how cars and trucks with internal combustion engines (ICEs) will be able to contribute to this goal.

Good progress has already been made on vehicle emissions under the most recent Euro 6 for light-duty and Euro VI for heavy-duty emissions regulations. Compliance is now also checked during on-road driving.

AECC has previously highlighted some areas where pollutants are still permitted at relatively high levels under these regulations. Such gaps in the current legislation can be improved by means of the future Euro 7.

AECC believes that three main principles are needed to ensure that ICE vehicles, including hybrid vehicles, continue to be part of the solution to reduce pollution levels in European cities. The legislation will need to focus on real world emissions, be fuel and technology neutrality, and consider a total system approach. 

Is it technically possible to further lower pollutant emissions from diesel and gasoline vehicles?

It certainly is. AECC and other key players have been working on demonstrating how internal combustion engine equipped cars will be able to achieve the ‘ultra-low’ real-world emissions.

A range of advanced emission control and powertrain technologies are being used, both in gasoline and diesel vehicles to achieve these emissions reductions. For example, catalysts placed nearer to the engine to have a faster light-off and heat-up, as well as heating strategies to keep the emissions control system warm, ensure lowest pollutant emissions in a broad range of driving conditions, particularly under urban operation.

Technology developments have shown that both gasoline and diesel cars can achieve similar ultra-low levels of emissions. AECC has demonstrated how the already low emissions from gasoline and diesel vehicles can be further reduced under cold start and urban operations.

A fuel- and technology-neutral approach will benefit a future Euro 7 legislation. The Euro 7 framework will incentivise innovation on emission control technologies. As it has been shown on the AECC ultra-low diesel demonstrator (ULED), emissions can be reduced in a broad range of conditions, but certain limitations remain. As an example of this, very short trips are still a challenge and further reduction of the cold start emissions are required.

For heavy-duty vehicles like trucks and buses, testing has shown that even with significant improvements under the Euro VI-D legislation, high emission events still occur. AECC is carrying out a vehicle demonstrator programme to show that better integration, including close-coupled catalysts, as well as appropriate volumes of currently available emission control technologies can reduce pollutant emissions in a broad range of real-world operating conditions.

A similar programme has been conducted by Southwest Research Institute (SwRI) in the United States, where a team of engineers achieved  very low (~26.8 mg/kWh ) nitrogen oxides (NOx) emission . The best-performing system, shown below, uses an additional selective catalytic reduction (SCR) catalyst close to the engine. This is showing us what can be done and the next emission standards will kick-start this innovation to happen.

Source: SwRI

But, how about CO2 emissions?

Climate change is a major challenge that we are facing as a society, and the contribution to the greenhouse gas emissions by road transport is still significant. The industry must ensure that all vehicles reduce their carbon footprint. This can be done by using renewable and sustainable fuels which are an important tool to reduce CO2 emissions on current and future fleet.

AECC and IAV have shown (figure below) that using renewable fuel (e.g. hydrogenated vegetable oil – HVO) in the ULED demonstrator vehicle resulted in comparable NOx emissions.

Source: MTZ 2020

Tightening road vehicle emissions limits and ensuring that testing more accurately reflects real-world driving, will have a clear beneficial impact on air quality in Europe. This will help the EU move towards its goal of zero emissions. Without significant government subsidies, battery electric vehicles remain less cost-efficient than internal combustion engine vehicles which will continue to be needed to have clean, efficient, convenient and affordable mobility.

By taking a total system approach and legislating for the lifetime of the vehicle, the European Commission will ensure that Euro 7 cars continue to meet the regulations over their lifetime.