Acid Activated fly Ash, as a Novel Solid Acid Catalyst for Esterification of Acetic Acid

An efficient solid acid catalyst (AAFA) has been synthesized by mechanical and thermal activation of F-type fly ash (SiO2 and Al2O3>70%) followed by chemical activation using concentrated HCl at 110oC. The activation of fly ash resulted in increased silica content (79%) and surface area (5.42 m2/g) having sufficient silanol activity for esterification of n-butanol and acetic acid. The catalyst was characterized by XRD, FT-IR, and SEM techniques. The product n-butyl acetate is an important fine chemical intermediate, widely used in pharmaceutical and as flavoring agent in confectionary. The catalyst was completely recyclable without significant loss in activity up to five reaction cycles, which confers its stability during reaction. The work reports an innovative use of solid waste fly ash as an effective solid acid catalyst.