Tackling vehicle emissions

Testing, regulations and research drive a push towards cleaner vehicles.

Spikes of particulate emissions of more than 1,000 times the normal rate have been found in two popular Euro 6d-temp diesels. This was caused by the periodic regeneration of diesel particulate filters (DPFs). The test by Ricardo, commissioned by the environmental NGO Transport & Environment (T&E) examined a Nissan Qashquai and an Opel/Vauxhall Astra and revealed that  the particle number emissions exceeded the limit by between 32-115% on all tests in which a full DPF regeneration occurred.

Simulating real-world driving, the lab tests measured pollutants including ultrafine particles, volatile and semi-volatile particles and ammonia which are currently unregulated and difficult to measure on the road. Where there was no regeneration in the tests, the vehicles were within their legal limits for gaseous pollutants and particulate matter (nitrogen oxides, carbon monoxide, total hydrocarbons, total hydrocarbons and nitrogen oxides, particulate matter.

There is a significant gap in the current Euro regulations because they don't apply the legal limit to regeneration tests. This means that between 60-99% of emissions of all regulated particles is ignored for the two test cars. It's significant to note that current regulations ignore large amounts of particle pollution which are potentially the most harmful to health.

A draft UN regulation is set to create a single approval for all major markets for emissions test procedures. More than 53 countries are either signatories to the UN regulations or adopt them unilaterally. Manufacturers will have to meet stringent emission limits for all kinds of driving environments for hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx) and particulate matter (PM). Additionally, a specific accelerated ageing test will be introduced to guarantee that new vehicles’ pollution control devices remain fully effective up to 160,000 km (99,419 miles).

The draft regulation will be submitted to the World Forum for Harmonization of Vehicle Regulation (WP.29) for adoption at its next meeting in June 2020, and entry into force in January 2021.

Meanwhile emissions from trucks are the focus of an Advance Notice of Proposed Rule (ANPR) by the US Environmental Protection Agency as part of the Cleaner Trucks Initiative. Following petitions from more than 20 organisations to revise and promulgate more stringent oxides of nitrogen (NOx) standards, the proposed rule aims to reduce costs for engine manufacturers by streamlining and improving certification procedures. 

The Truck and Engine Manufacturers' Association (EMA) President Jed Mandel said, "EMA looks forward to working with EPA on potential improvements to the heavy-duty on-highway engine regulations that can reduce the overall costs of compliance, preserve the necessary diversity of the commercial vehicle marketplace and protect our customers' need for fuel-efficient, durable and reliable trucks."

The EPA is seeking input from the public and all interested stakeholders. The full text of the ANPR can be found here.

Research by Ecole polytechnique fédérale de Lausanne (EPFL) has revealed the potential to reduce trucks CO2 emissions by almost 90%. The CO2 is captured within the exhaust system, converted into a liquid and stored on the vehicle. It is then delivered to a service station where it will be converted into fuel using renewable energy. The concept is being patented and is the subject of a paper.