Gas and soot formed in the dimethoxymethane pyrolysis. Soot characterization

The many simultaneous processes occurring within in a diesel engine make difficult a thorough understanding of the mechanisms responsible for reduction of soot and/or NOX when an oxygenated compound is added to diesel fuel. Thus, in order to explore the use of oxygenated compounds as biofuels/additives, it is interesting to study their conversion under well-controlled laboratory conditions, together with kinetic studies that help to interpret and understand the reaction schemes that occur during such processes. The aim of this work has been to contribute to the knowledge of the dimethoxymethane (DMM) pyrolysis, one of the oxygenated compounds proposed in literature as alternative fuel. In this way, the influence of pyrolysis temperature (1075-1475 K) and inlet fuel concentration (33,333 and 50,000 ppm DMM) on the sooting propensity of DMM, soot reactivity and its properties is analyzed. Therefore, this work includes pyrolysis experiments under different experimental conditions, focusing on the gas-phase analysis and the soot formation, together with a gas-phase model. Additionally, the interaction of soot with O2 and with NO has been studied, and since soot properties are important on the oxidation rate, selected soot samples have been characterized by different instrumental techniques (elemental analysis, physical adsorption with N2, Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), and Raman spectroscopy).