Mechanism of hydrocarbon generation from sodium stearate decarboxylation by microwave assisted pyrolysis

Renewable hydrocarbon fuel have significant advantage to biodiesel (fatty acid methyl ester). The purpose of present study was to explore decarboxylation mechanism of fatty acid sodium salt with microwave radiation. Sodium stearate (C₁₈) was chosen as a model compound, the carboxy-terminal of this dipolar molecular was further polarized with microwave radiation. The Lorentz force of ions or dipolar molecules were moved in accordance with the way of electromagnetic waves, contributing to the formation of carbanion, which effectively promote the decarboxylation reaction. Glycerol possessing high dielectric constant were added which formed a "high-temperature locus" that lowed the activation energy of decarboxylation reaction and played a role as the hydrogen donor. The liquid products were analysed and the results showed C₈~C₂₀ n-alkanes and n-alk-1-enes were arranged regularly which complied with the law of hydrocarbon pyrolysis. All the work proved the feasibility of deriving renewable hydrocarbon fuel from fatty acid sodium salt by microwave pyrolysis.