Emissions from vehicle traffic affect both people and the environment greatly. The different types of emissions are global and local emissions. The global emissions primarily affect the climate, of which the most important emission is carbon dioxide, CO2. These emissions are very hard to remove from combustion engines; however, you can reach net-zero emissions through using renewable fuels.
The local emissions directly affect the local environment and people’s health. The most common and important local emissions are particles and nitric oxide. Particles go deep into our lungs, and can cause allergies and diseases, and nitric oxide contributes to acidification and eutrophication.
In the future, emission limits will probably be much stricter, while engines need to be more efficient. This is a challenge that we are well on our way to solve, but it requires both research and political decisions to reach this goal.
Thus, an obvious goal for Combustion and Propulsion Systems is research focusing on combustion with zero emissions, while maintaining high efficiency. Furthermore, catalysts and purification systems must be developed to work optimally in all conditions, including for example cold starts and accelerations. This is done in several projects where post-treatment systems are studied, both in detail and with a system perspective.
Examples of other areas of research in post-treatment systems are particulate emissions in dual-fuel systems and removal of particles and NOx.