Deoxygenation of Oleic Acid Methyl Ester in FCC Process Conditions Over Protonated and Sodium Exchanged Y and ZSM-5 Zeolites

Abstract

One way to take advantage from out of speci cation biodiesel and waste from biodiesel tank bottom drainage is to co-process them in a uidized catalytic cracking (FCC) unit. The present work deals with the cracking of oleic acid methyl ester (OAME) as a biodiesel model, under conditions close to that of FCC process over ZSM-5 and Y zeolites, either in protonated or sodium forms, for the production of deoxygenated compounds. Catalytic fast cracking of OAME pre-adsorbed on the catalyst surface was performed, with a catalyst:OAME mass ratio of 10:1 in a micro-pyrolysis system at 650°C, coupled to a GC/MS for on line analysis of the products. Results show that the cracking of OAME without a catalyst favored the formation of linear alkenes and polyenes. Fast cracking of OAME over HZSM-5 and HY acidic zeolites led to the production of aromatics, due to hydrogen transfer. Cracking over NaY and HY zeolites produced remarkable amounts of rami ed saturated hydrocarbons. The formation of alkylated hydrocarbons was not signi cant over ZSM-5 zeolite probably due to a small pore size of this zeolite.NaY catalyst favored the production of hydrocarbons in the range of kerosene (C8-C12). Low acidic zeolites favored the production of non-aromatic hydrocarbons. Product distribution was affected by catalyst shape selectivity and acidity. These results show that residues from the biodiesel chain can be directly co-processed in FCC units to obtain high value hydrocarbons, mainly in the jet fuel and gasoline ranges. Statement Of NoveltyThis work shows that oleic acid methyl ester as a model of residues from off-spec biodiesel and waste from biodiesel tank bottom drainage can be directly co-processed in a FCC unit, using ZSM-5 and Y zeolites as catalysts in H-and Na-form. The use of such residues in FCC process can promote the production o high value hydrocarbons, mainly in the jet fuel and gasoline ranges. These results may be of great interest to the growing market for renewable jet fuel since the aviation industry is committed to reduce CO2 emissions towards zero net carbon emissions. To the best of our knowledge, such a systematic study has not been reported yet.