Production of bio-olefins from oleic acidvia oxidative dehydrogenation using vanadium oxides/sba-15 catalysts

Abstract

Long-chain olefins (≥C10) are important commodity chemicals, which are primarily used to manufacture everyday products such as plastic packaging, surfactants and detergents in cleaning products, and lubricant oil additives. However, the long-chain olefins are currently synthesized from the petroleum refining process via ethylene oligomerization or thermal cracking of long-chain paraffins. To support the Bio-Circular-Green Economy (BCG) model, the direct synthesis of olefins from renewable feedstocks has become an attractive route to promote overall sustainability. The objective of this research was to study the possibility to transform oleic acid (OA), one of the unsaturated fatty acids in palm oil, to produce the long-chain bio-olefins via oxidative dehydrogenation (ODH) using an nVxOy/SBA-15 catalyst. The effects of various parameters such as vanadium content (0.5, 1.0, 3.0, and 5.0 wt%), reaction temperature (400-550 °C), processing time (2, 6, 8 h), and reusability of the catalyst on the OA conversion and the selectivity to olefins in the liquid and gaseous products was investigates. It was found that the ODH of OA using 1.0%VxOy/SBA-15 catalyst carried on at 450 oC for 2 h provided the best OA conversion (83.7%), whereas the 0.5%VxOy/SBA-15 catalyst obtained the high selectivity to long-chain olefins with carbon atoms in the range of C7-C17 (44.6%). However, the higher reaction temperature at 550 oC promoted the aromatization for producing 25.4% of aromatic compounds. Moreover, the long-time process (6-8 h) and catalyst regeneration above 1st cycle decreased the catalyst performance due to the catalyst’s structure collapse and increases in coke formation, respectively.