Estudo da cinética da combustão de metanol em ar com ignição por descarga elétrica de uma vela veicular

Abstract

This study investigates the behaviour of chemical species in different mixtures of air and methanol (CH3OH) under conditions of spark discharge from the ignition plug. Using experimental parameters such as reduced electric field, electronic temperature, and electron density, we explore the effects of discharge in various scenarios through numerical simulation. The research addresses the complexities of plasma-assisted combustion, examining the role of reactive oxygen and nitrogen species (RONS) and key reactants such as H, OH, and H2O in methanol decomposition. Employing a comprehensive model composed of 112 interconnected species by 1081 physical and chemical processes, including shock sections resulting from electron impact. We highlight the adoption of two distinct approaches: the first considered two different sets of operating parameters for the ignition plug. In contrast, the second analyzed different values for methanol concentration (5% and 2.5%) in the mixture. We observe the impact of discharge parameters on species density, emphasizing the production of atmospheric pollutants (NOx, CO, CO2, and CH2O), and the predominance of parameters for the 10% duty cycle over the 40%, along with the importance of the 5% air and methanol mixture resulting in higher densities and production and consumption rates for most species compared to the 2.5% mixture. Through meticulous investigation of reaction pathways, the study highlights critical plasma-chemical processes and their ramifications in combustion and environmental pollution. The findings offer fundamental insights into the mechanisms governing combustion and oxidation processes, presenting significant contributions to the advancement of more efficient and environmentally sustainable combustion technologies.