Changes of Air Pollution and Climate Forcing Emissions due to Fuel Switching to Gasohol in Motorcycle Fleet in an Urban Area of Thailand

Abstract

This research aims to examine the exhaust emission changed due to fuel switching to gasohol in actual motorcycles (MC) fleet in Nakhon Pathom municipality, Thailand. International Vehicle Emissions (IVE) model was applied by specifying the year 2010 as a base case and the target year of 2020 as Business as Usual (BAU). The parking lot survey, GPS monitoring and MC counting on selected roads during weekday and weekend were conducted. Fuel switching from gasoline octane number 91 to gasohol in all MC fleet in the municipality was set as a scenario according to current Thailand’s transport energy policies. Total pollution emissions reduction of the following pollutants after switching to gasohol E10 (10% of ethanol) for all MC in the fleet compared to BAU were obtained: benzene (86%), 1,3-butadiene (69%), VOC (including evaporation) (31%) and CO (29%), while the following pollutants increased: acetaldehydes (>100%), formaldehydes (51%), NOx (9%) and PM (5%). Gasohol use scenario produced larger amount of CO2 (29%) and CH4 (9%). Only a small deviation of climate forcer emissions in CO2-equivalent (reduced by 8% for 20-year and increased by 2% for 100-year horizon) were obtained. Switching to gasohol in MC fleet in Nakhon Pathom municipality unable to achieve air quality and climate co-benefit. Restriction of the local emission factors (EFs) available for adjusting the model’s EFs can be influence to the emission calculation. Also, as PM was excluded from the calculation of GWP due to lack of OC and EC information, this can affect the analysis of climate forcer emissions.

Keywords

• gasohol
• climate co-benefit
• motorcycles
• IVE model
• fuel switching