Formation and burning of soot particles in a diesel cylinder when working on ethanol-fuel emulsion

Abstract

The chemistry of the processes of formation and burning of soot particles in a diesel cylinder is associated with a large number of chemical reactions and is very complicated. During combustion, the fuel supplied to the engine cylinder does not completely burn out. Complete combustion is hindered by a number of factors: the limited mixture formation and combustion processes in time, the imperfection of the fuel supply and atomization processes, and the uneven concentration of oxygen and fuel. So, with a lack of air and a high temperature of the air charge in the engine cylinder, the supplied fuel undergoes pyrolysis with the formation of products of incomplete oxidation: carbon monoxide, aldehydes, carboxylic acids, soot, and various heavy hydrocarbons. Soot has a large specific surface area, up to 75-80 m2 / g, which leads to its high absorbent capacity. Therefore, when it settles in the engine’s exhaust system, soot absorbs unburned hydrocarbons like a sponge, forming black, ointment-like deposits. With increasing temperature of the exhaust gases, for example, with an increase in engine load, these deposits are prone to ignition.