Comparison of CO2 Emissions from Vehicles in Thailand

Abstract

Emission of carbon dioxide (CO₂), a greenhouse gas, from typical passenger vehicles in Thailand was investigated using a chassis dynamometer in the Automotive Emission Laboratory. The vehicle running method was controlled under the standard Bangkok driving cycle. CO₂ emissions were measured at three different speeds for the following four vehicle types commonly used in Thailand: heavy duty diesel (HDD), light duty diesel (LDD), and light duty gasoline (LDG) vehicles and motorcycles (MC). HDD vehicles had the highest average CO₂ emission rate, followed by LDD, LDG and MC at 1,198.8±93.1, 268.4±21.3, 166.1±27.7 and 42.5±6.1 g km^-1, respectively; all values were significantly different (p < 0.05) from each other. The effect of different fuel types, including diesel, gasoline 91, gasohol 95, gasohol 91, liquid petroleum gas (LPG) and natural gas for vehicles (NGV), on the CO₂ emission level was also compared. HDD vehicles had a higher rate of CO₂ emission when using either NGV or diesel, while LDD vehicles emitted more CO₂ with diesel than with NGV. For LDG vehicles, more CO₂ was emitted with gasohol 91 than with gasohol E20, LPG or NGV. Finally, MC had a higher average CO₂ emission rate with gasohol 95 than with gasoline 91 and gasohol 91 at any vehicle speed. The CO₂ emission rates obtained in this study can be used as a basis to create a database that supports development of an efficient transportation management system and reduced vehicular emission of greenhouse gases in Thailand.