The effect of diesel fuel compositions and distillation properties on PM production

Although the demand for petroleum products is expected to decrease in the future, the demand for diesel fuel remains relatively stable. In the production of diesel fuel, blending cracked fraction from heavy oil such as Light Cycle Oil (LCO) and kerosene is generally operated at a refinery in addition to utilizing the diesel fuel fraction from crude distillation unit. Cracked fraction contains higher aromatic and naphthenic components than straight-run diesel, while kerosene has lighter distillation properties. Previous research has shown that the compositions and distillation properties of diesel fuel affect the amount of particulate matter (PM) production. This study aims to quantitatively evaluate the impact of these factors on PM production through engine bench test, considering refinery operations. To evaluate the effects of fuel composition, the test fuels are prepared with significant variations in aromatic and naphthenic components, while maintaining other parameters such as distillation properties and cetane number at constant level. To evaluate the effect of distillation properties, two series of test fuels are prepared. One series varied the front side of distillation by adjusting kerosene content, while the other series varied the end side of distillation by the method of distillation fraction. The equation for estimating PM production is developed by a regression analysis of the results. The coefficients of the equation quantify the contribution of compositions and distillation properties on PM production. Aromatics were found to have greater impact on PM production than naphthenes, with naphthenobenzene contributing more significantly than alkylbenzenes. Additionally, both aromatics and naphthenes with polycyclic-structures were found to have greater impact on PM production than monocyclic-structures. The study also confirmed that lighter distillation properties, through both kerosene blending and distillation fraction method, effectively reduce PM production.