Demonstration of Low Criteria Pollutant and Greenhouse Gas Emissions: Synergizing Vehicle Emission Reduction Technology and Lower Carbon Fuels 2024-01-2121

This study focuses on evaluation of various fuels within a conventional gasoline internal combustion engine (ICE) vehicle and the implementation of advanced emissions reduction technology. It shows the robustness of the implemented technology packages for achieving ultra-low tailpipe emissions to different market fuels and demonstrates the potential of future GHG neutral powertrains enabled by drop-in lower carbon fuels (LCF).

An ultra-low emission (ULE) sedan vehicle was set up using state-of-the-art engine technology, with advanced vehicle control and exhaust gas aftertreatment system including a prototype rapid catalyst heating (RCH) unit. Currently regulated criteria pollutant emission species were measured at both engine-out and tailpipe locations. Vehicle was run on three different drive cycles at the chassis dynamometer: two standard cycles (WLTC and TfL) at 20°C, and a real driving emission (RDE) cycle at -7°C. Several EN228 compliant fuels, including lower-carbon fuel candidate, were tested. Fuels were formulated representing the distribution of volatility, C9 and higher aromatics (A9⁺), and C11 and higher aromatics (A11⁺) currently in the European market.

The results show that with ULE technology, a significant reduction in tailpipe emissions is achievable across various test cycles and conditions. It was found that fuel property effects on tailpipe emissions are mitigated by the ULE test vehicle. However, the engine-out total hydrocarbon (THC) and particle number (PN) emission showed sensitivity to fuel formulation. Fuel mid-distillation range was a good general predictor of engine-out THC emissions. Engine-out PN emissions were not consistently correlated with any fuel properties. However, Yield Sooting Index (YSI) in combination with back-end volatility was correlated with PN emissions on two of three test cycles on this vehicle.