Study on the correlation between mechanical and oxidation characteristics of methanol/biodiesel particulate matter

In order to effectively reduce the number of diesel exhaust particles and reduce particulate emissions, it is necessary to have a deep understanding of the mechanical and oxidation characteristics of diesel exhaust particles. For the combustion particles of methanol/biodiesel (BM5, BM10, and BM15), atomic force microscopy and thermogravimetric analyzers were used to study changes of particle in mechanical parameters and oxidation rules, and association impact analysis was performed. Biodiesel (B100) was used as a reference. The results showed that with the increase of methanol content, the attraction force F_at, the cohesive force F_ad, the adhesion energy W_ad, and Young's modulus E of the methanol/biodiesel particles all decreased significantly. During the oxidation process, the weight loss rate of SOF increased, while the content of soot decreased. In addition, the initial combustion temperature of the SOF component T_SOF and soot component T_soot in particles as well as the burn-out temperature T_end showed a downward trend. There was a certain correlation between the mechanical parameters and the oxidation properties of the particles. The smaller the mechanical parameters, such as the attraction force F_at, viscous force F_ad, the cohesive force F_ad, the adhesion energy W_ad, and Young's modulus E, the greater the looseness of the particles, the smaller the particle hardness and the degree of graphitization.