Regulations around the globe are driving the adoption of alternative fuels and vehicles through the implementation of stricter standards aimed at reducing carbon footprint and criteria emissions such as nitrogen oxides (NOx), particulate matter (PM), and total hydrocarbon (THC) emissions. Low emission zones have been implemented across Europe which restrict access by some vehicles with the aim of improving the air quality. The Paris Agreement on climate change declared governments’ intentions to reduce greenhouse gas (GHG) emissions as outlined in each country’s nationally determined contribution. Providing affordable energy to support prosperity while reducing environmental impacts, including the risks of climate change, is the dual challenge for the energy and transport industries.
Development and deployment of low-emission liquid fuels and complementary engine hardware optimization could provide options to meet air quality as well as proposed, ambitious greenhouse gas (GHG) reduction targets. To take advantage of these potential benefits, these fuels must be compatible with the existing fleet and comply with current fuel standards. This work represents a joint effort by Porsche and ExxonMobil Research & Engineering Company. The goal of this work is to evaluate the potential of low-emission fuels to improve tailpipe emissions from in-use and new vehicle fleets.
In this study, a number of fuels with various qualities and low-emissions potential were tested for resulting criteria emissions (NOx, PM, THC). A research Porsche single cylinder engine, including advanced engine combustion design elements, was used for combustion and emissions analysis. The tests were done under stationary and dynamic load as well as under different temperature conditions.
Significant reductions to criteria emissions were obtained with the new fuel formulations, when compared to an existing European market fuel. Reductions of more than 90% in particulate emissions, 10 to 20% in NOx emissions, and up to 30% in THC emissions were achieved. Additionally, vehicle test results on both, a 1996 993 and a 2016 991.2 Porsche Carrera, with some selected fuels are presented and compared. Emission reduction potential with the 993 (23 years old vehicle) were similar to the 991.2 by using the low emission formulations showing the potential of the fuels in legacy vehicles, not equipped with gasoline particulate filters (GPF), to comply with current emission regulations. Furthermore, these fuels can be formulated to be compliant with existing European fuel regulations.
