Green Synthesized TiO2 NPs Based Mixed Metal Oxide Catalyst for Biodiesel Production from Waste Biomass Oil

Abstract

The ongoing energy crisis and global warming issues have pushed the research community to search for sustainable energy supplies such as biodiesel. In this regard, inedible oils which are not consumed by humans could be potential biodiesel sources. Herein, the biodiesel was produced by trans-esterifying the apricot seeds oil (ASO) employing series of green synthesized (mediated by banana peel extract) TiO2 based NiO-TiO2 heterogeneous nano-catalysts with varying loadings of NiO (5, 10 and 15 by weight percent). The as-prepared catalysts were characterized using advanced techniques like FT-IR, XRD, SEM and FE-SEM. These studies established the successful impregnation of NiO with TiO2 NPs. The efficiency of NiO-TiO2 with 10 wt% of NiO loading calcined at 500 °C was superior to other nano-catalysts. The parametric study of transesterification reaction to yield biodiesel adapting this catalyst revealed the maximum yield (93.4 %) with MeOH : oil and catalyst loading of 20:1 and 2 wt% correspondingly in 1 h at 55 °C. GC-MS analysis was executed for investigating and confirming the composition of obtained biodiesel at optimized conditions. Furthermore, the heterogeneous catalyst was reusable for five cycles without regeneration for transesterification of ASO. In addition, fuel characteristics such as calorific and acid value were measured by using titrations and bomb calorimeter respectively and compared with ASTM6751 and EN14214 standards.