Nitration Intensification of an Aliphatic Compound in Micellar Medium with Cationic Surfactant to Synthesize a Bioadditive

The objective of this work is to intensify the global rate of the nitration reaction of a vegetable oil using a micellar medium in order to synthesize a biobased cetane improver. The vegetable oil is a biodiesel composed mainly of methyl oleate. The use of micelles enables greater mass transfer between the organic and aqueous phases by solubilizing the oil within the nitrating agent contained in the micelles. Cationic surfactants are used because they demonstrate higher efficiency in this type of medium. The exothermic nitration reaction kinetics are monitored using an RC1 calorimetric reactor, and the stability of the micellar medium is analyzed by DLS. The final product was characterized using various techniques such as iodine value determination, GC-MS, and ESI-MS. The final product consists of four chemical compounds: methyl 8-nitro oleate, methyl 10-nitrate stearate, methyl 10-nitrate 9-nitrostearate, and methyl 8-nitro-9-nitrostearate, whose selectivity varies according to the synthesis temperature and surfactant concentration. A chemical model of the nitration process is proposed, and the thermal power profiles released by the reaction mixture are used to estimate the energetic and kinetic parameters of the reaction. Moreover, a Cooperative Fuel Research (CFR) engine was used to determine the cetane number of a reference diesel blended with 5 vol % of the bioadditive in accordance with ASTM D613. The results showed an increase of 5.7 cetane number points.