Catalytic Conversion Of Oleic Acid To Dimethyl Azelate

Azelaic acid and dimethyl azelate are very important organics which can producechemical raw material and synthesis intermediate,and mainly used in the synthesis ofdioctyl azelate plasticiser.There are also applied in the productions of medicine，food，chemical，automobile industry. Supported catalyst used for ozonization,oxicrackingand esterification of oleic acid to prepare dimethyl azelate was studied,as well asnew reactor.In the present investigation, the oxidation of ozonized oleic acid was investigatedin an adsorption-film reactor. The investigation indicated that SiO₂is a good absorbantfor both oleic acid and it’s ozonide. The influences of reaction temperature, reactiontime, and alcohol esterification conditions of oxidation products on product yieldswere investigated. The investigation discovered that when the esterification reactionswere carried out over WO₃/SiO₂and MoO₃/SiO₂catalysts at200℃for4h. Metaloxide catalysts supported on SiO₂were investigated and MoO₃/SiO₂and WO₃/SiO₂were found to be good catalysts, which given high Dimethyl azelate yields. Thecatalyst loading amount and reaction conditions were also investigated for theesterification-desorption reaction,10wt%MoO₃/SiO₂-450and10wt%WO₃/SiO₂werefound to give the highest product yields. The ozonation reaction time and reactiontemperature of oleic acid and the reaction conditions of oleic acid oxidation wereinvestigated, and optimized reaction conditions were obtained for the whole reactionprocess of oleic acid oxidation to prepare dimethyl azelate. At the optimized reactionconditions,50.88%of Dimethyl Azelate yield was obtained.The Stability of catalyst10wt%MoO₃/SiO₂was tested.The specific surface areaanalysis and TG-DSC analysis of used catalyst showed that coking on the surface ofcatalyst was the reason that leaded to catalyst deactivation.The investigation indicated that azelaic acid may insituly formed from theoxidation of oleic acid ozonide, and then esterified over acid site to form the finalester products. The oxidation of oleic acid ozonide was carried out over the MoO₃orWO₃catalysts. Since the absorbant offered a high surface area for the adsorption ofoleic acid ozonide, the farther oxidation could more easily conducted.