Catalytic depolymerisation of isolated lignins to fine chemicals using a Pt/alumina catalyst: part 1—impact of the lignin structure. Issue 2 (2nd December 2014)

• Record Type: Journal Article
• Authors: Bouxin, Florent P.; McVeigh, Ashley; Tran, Fanny; Westwood, Nicholas J.; Jarvis, Michael C.; Jackson, S. David
• Is Part Of: Green chemistry. Volume 17:Issue 2(2015)
• Page Start: 1235
• Page End: 1242
• Publication Date: 2014-12-02
• Subjects: Environmental chemistry -- Industrial applications -- Periodicals; Environmental management -- Periodicals; 660
• DOI: 10.1039/c4gc01678e
• Languages: English
• ISSNs: 1463-9262

Abstract

Abstract : Catalytic depolymerisation of lignins with different β- O -4 linkage percentages affected both the yield and the nature of aromatic monomeric products. Abstract : Four lignin preparations with different contents of alkyl–aryl ether bonds were depolymerised using an alumina supported platinum catalyst. The results showed that the proportion of β- O -4 linkages is the crucial factor for both the yield and the nature of the monomeric products. Highly condensed lignin generated mainly non-alkylated phenolic products while uncondensed lignin generated mainly phenolic products retaining the 3-carbon side-chain. These phenolic products with the 3-carbon chain still attached were considerably less abundant than the maximum potential yield calculated from selective cleavage of alkyl–aryl ether bonds by thioacidolysis, demonstrating that the scope for improved yield remains. Although the catalytic conversion yield rose with an increasing content of labile ether linkages in the lignin structure, optimisation of the catalytic depolymerisation was increasingly required to minimize side reactions. Gel permeation chromatography showed that the products converged towards the same molecular weight distribution regardless of the starting material. The full potential of the highly uncondensed lignin was reached only after the minimisation of condensation reactions during the catalytic conversion.