Gasoline Direct Injection Engine Emissions of OC and EC: Laboratory Comparisons with Port Fuel Injection Engine

Abstract

To better understand carbonaceous aerosol emissions from gasoline vehicles, a gasoline direct injection (GDI) vehicle with and without a gasoline particle filter (GPF) installed and a port fuel injection (PFI) vehicle were tested on a chassis dynamometer using standard emission drive cycles. Carbonaceous particles emitted from the vehicles were collected on quartz filters and analyzed using three different thermal optical protocols to assess the sensitivity of organic carbon (OC) and elemental carbon (EC) emission estimates to the methods, showing OC obtained by the IMPROVE and EC by the NIOSH protocol was the lowest. Compared to the PFI vehicle, the GDI vehicle had higher EC and OC emissions under cold-start cycles by 1415% and 46%, respectively. However, the OC emission from the PFI vehicle was higher than GDI during an aggressive driving cycle by 146%. By considering OC collected on a quartz filter behind a Teflon filter, the emissions from PFI vehicle were found to be more volatile than the GDI vehicle. This is consistent with the OC forming characteristics for GDI and PFI engines, which are pyrolyzed particles from incomplete combustion and incomplete volatilization of fuel droplets, respectively. Generally, the particle phase OC emissions from gasoline engines are more volatile than other sources (e.g., biomass burning), supported by the very low level of pyrolyzed organic carbon (POC) and small differences among protocols in the current study. Once the GDI vehicle was equipped with a GPF, the removal efficiency of EC was > 98%, but OC emissions could increase as a result of regeneration, suggesting that the effect of a GPF on total carbon emitted to the atmosphere needs further evaluation, especially considering the formation of secondary organic aerosol.

Determination of Vehicle Emission Rates for Ammonia and Organic Molecular Markers Using a Chassis Dynamometer

“…According to Zhang et al [45], a significant proportion of pollutants emitted from vehicles consists of organic components. In this study, exhaust gas samples were collected and analyzed during driving in the US06 and CVS-75 modes to determine the ER of OC and EC based on the fuel type.…”

“…OC and EC emissions were quantified using quartz filters for gas collection, and the results are presented in Table 6. Diesel engines are extensively utilized in various applications such as vehicles, ships, and construction machinery due to their high thermal efficiency, cost-effectiveness, and durability [1,45]. However, the widespread use of diesel engines also contributes to significant environmental pollution issues [32].…”

“…To mitigate PM emissions, the installation of DPF in diesel vehicles has become crucial for effective exhaust gas emission control, considering the substantial role of diesel vehicles as a major source of PM production [1]. Nevertheless, despite the oxidation and combustion of most PM during vehicle operation, non-volatile substances such as elemental carbon, ash, and soot persist [7,32,45]. Hence, this study focused on analyzing the carbon content by capturing exhaust gas during DPF regeneration (DPFre) using EURO6 vehicles (EURO6 DPFre).…”

Energy Saving and Pollutant Emission Reduction by Adding Hydrogen in a Gasoline-fueled Engine

“…Many people suffered from high traffic contamination exposure when they stay in the near road, stop at a traffic light or spend time during heavy traffic circumstances (Tsai et al, 2020;Yu et al, 2021). Also, the traffic-related air pollutants could be considered as critical issues related to human health (Tsai et al, 2020;Zhang et al, 2022).…”