Science of the Total Environment
Formulation of biodiesel (C-18 ester links) is attracting lots of attention in recent times owing to their sustainability, economic aspects and simple operational technique. Alcoholysis or trans esterification is the effective technique to yield FAME (fatty acid methyl esters) or biodiesel. The catalyst system is an influential factor for this research and broader choices of catalysts are explored. Chemical and biological catalogues of catalysts include acids, bases, oxides, carbonates and porous ex. zeolites and mesoporous materials. The intensive research on chemical catalysts in homogeneous media points at challenges in separation of catalyst from the products and thermal instability. In the need of major advancements towards convenience, heterogeneous catalysts have evolved as defensive catalyst with predictive efficiency. However, in depth studies these types faces setback in selectivity and limited activity issues. Furthermore, biocatalysts leads in context of mild operating conditions and good selectivity. But, the attractive features get masked with operational costs. Nanotechnology has created niche in this alternative fuel industry based on their excellent reactivity with selectivity and lower reaction time owing to their higher surface area and small pore size. Nano sized catalysts plays a pivotal role in heterogeneous phase catalysts as well as in lipase immobilization. This article will enlighten the knowledge of catalysts applied in biodiesel synthesis, their prospects and challenges in the burgeoning renewable fuel market. The review also covers the pertinence of biodiesel produced using these catalysts and their attractive features.
