- Esterification of levulinic acid over Sn(II) exchanged Keggin heteropolyacid salts: An efficient route to obtain bioaditives
-
In this paper, we describe a process to add value to the biomass derivatives (i.e., levulinic acid), converting it to bioadditives over solid Sn(II) exchanged Keggin heteropolyacid salts. These solid catalysts are an attractive alternative to the traditional soluble and corrosive Br?nsted acid catalysts. Among Sn(II) heteropoly salts, the Sn1.5PW12O40 was the most active and selective catalyst, achieving high conversions (ca. 90 %) and selectivity (90–97 %) for alkyl esters and angelica lactone, the main reaction products. The impacts of the main reaction parameters (i.e., catalyst load, temperature, and the molar ratio of alcohol to acid) were investigated. The use of renewable raw material, and an efficient and recyclable catalyst are the main positive features of this process. The Sn1.5PW12O40 catalyst was easily recovered and reused without loss activity.
- Da Silva, Márcio José,Chaves, Diego Morais,Teixeira, Milena Galdino,Oliveira Bruziquesi, Carlos Giovani
-
-
- Catalytic upgrading of α-angelica lactone to levulinic acid esters under mild conditions over heterogeneous catalysts
-
Butyl levulinate was prepared starting from α-angelica lactone and butanol over Amberlyst 36. Different reaction conditions were optimized, which resulted in full conversion and 94% selectivity toward the ester at 75°C. A reaction network analysis reveals pseudo-butyl levulinate and levulinic acid as intermediates in the preparation of butyl levulinate. The mild protocol was successfully applied for different alcohols and compared with the esterification of levulinic acid. Overall, this study identifies α-angelica lactone as a better candidate than levulinic acid for the heterogeneously catalysed preparation of levulinic acid esters. A catalyst screening shows that also zeolites and zirconia-based catalysts are able to catalyse the reaction. However, the transformation of the intermediate pseudo-butyl levulinate into butyl levulinate requires acid sites of sufficient strength to proceed.
- Al-Shaal, Mohammad G.,Ciptonugroho, Wirawan,Holzh?user, Fabian J.,Mensah, Joel B.,Hausoul, Peter J. C.,Palkovits, Regina
-
p. 5168 - 5173
(2015/11/27)
-