Effects of Fuel Adulteration on the Emissions from Spark Ignition Engines
Automotive spark ignition engines are designed to run on specific fuels. Alteration of the specification of the fuel leads to changes in performance and emissions of engines. Blending of fuels such as kerosene and diesel, used lubricant, and industrial solvents such as xylene and toluene is considered to be clandestine fuel adulteration practice and is a widespread problem in South East Asian countries. This blending may cause suboptimal performance of the engines and may increase emissions of CO, HC, NOx, SOx, particulate matter and polycyclic aromatic hydrocarbons (PAHs), due to the change in combustion dynamics with the alteration in the physical and chemical characteristics of the fuel. Results from various studies have shown that the emissions are significantly influenced by the chemical structure and physical properties such as boiling point and viscosity, of the spark ignition engine fuel. However, most of these studies involved known fuels blends of relatively simple hydrocarbons and the octane number was controlled. Consequently, the effect of blending heavier fuels like kerosene with gasoline, resembling one of the most common forms of adulteration has not been sufficiently addressed. This study uses custom kerosene adulterated fuels to determine the influence of the amount of kerosene in the blend on the regulated emissions. In addition, an engine simulation program, ISIS, is used to simulate some of the exhaust emissions to compare with experimental values and help understand the experimental results.