Synthesis of n-Butyl Levulinate Over Caesium Containing Heteropoly Acid Supported Zeolite β Catalysts

The aim of the present work is to investigate an environmentally benign method for the catalytic conversion of biomass derived compounds into fine chemicals. Levulinic acid (LA) is one of the key biomass-derived chemicals that can be converted into biofuels and various other value-added chemicals. n -Butyl levulinate ester is an important chemical used in the production of fuel additives, solvents, plasticizing agents, and odorous substances. The work presented here focused on the esterification of n-butyl levulinate by reaction of LA and n-butanol in the presence of synthesized 20% tungstophosphoric acid (TPA) supported zeolite β (TPA-Zβ), CsTPA-Zβ and Cs-Zβ catalysts. Various catalyst characterization techniques have been used, specifically, XRD, SEM–EDS, FT-IR, nitrogen physisorption and NH₃ -TPD. The highest % yield of n -butyl levulinate is obtained with shorter reaction time in the case of a 20% TPA supported zeolite β catalyst, calcined at 300 °C. The addition of Cs ions to TPA appears to improve catalytic performance.

Graphical Abstract