Particle Number Emissions of Gasoline, Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) Fueled Vehicles at Different Ambient Temperatures

Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) are included in the group of promoted transport fuel alternatives for traditional fossil fuels in Europe. Both CNG and LPG fueled vehicles are believed to have low particle number and mass emissions. Here we studied the Solid Particle Number (SPN) emissions >4 nm, >10 nm and >23 nm of vehicles applying CNG or LPG and gasoline fuels in laboratory at 23C and sub-zero (-7C) ambient temperature conditions. The SPN23 emissions in CNG or LPG operation modality at 23C were below the SPN23 limit of diesel and gasoline direct injection vehicles 6x10^11 1/km. Nevertheless, the limit was exceeded at sub-zero temperatures or when sub-23 nm particles were included or when gasoline was used as a fuel. The key message of this study is that gas-fueled vehicles produced particles mainly <23 nm and the current methodology might not be appropriate. However, only in a few cases absolute SPN >10 nm emission levels exceeded 6x10^11 1/km when >23 nm levels were below 6x10^11 1/km. Setting a limit of 1x10^11 1/km for >10 nm particles would also limit most of the >4 nm SPN levels below 6x10^11 1/km.

LAHDE Tero;  GIECHASKIEL Barouch; 

2021-07-19

MDPI

JRC125583

2073-4433 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC125583,   

10.3390/atmos12070893 (online),