Effect of Cetane Improver on Combustion and Emission Characteristics of Coal-Derived Sasol IPK in a Single Cylinder Diesel Engine

Sasol IPK is a coal-derived synthetic fuel under consideration as a blending stock with JP-8 for use in military ground vehicles. Since Sasol IPK is a low ignition quality fuel with Derived Cetane Number (DCN) of 31, there is a need to improve its ignition quality. This paper investigates the effect of adding different amounts of Lubrizol 8090 cetane improver to Sasol IPK on increasing its DCN. The experimental investigation was conducted in a single-cylinder research type diesel engine. The engine is equipped with a common rail injection system and an open Engine Control Unit (ECU). Experiments covered different injection pressures and intake air temperatures. Analysis of test results was made to determine the effect of cetane improver percentage in the coal-derived Sasol IPK blend on autoignition, combustion and emissions of carbon monoxide (CO), total unburned hydrocarbon (HC), oxides of nitrogen (NOx), and particulate matter (PM). In addition, the effect of cetane improver on the apparent activation energy of the global autoignition reactions was determined.