Catalytic Oligomerization of Furfuryl Alcohol over Homogeneous and

Heterogeneous Catalysts

Xiaojun Chan,[a] and Taejin Kim[a, b]

a Department of Materials Science and Engineering, Stony Brook University, Stony Brook, NY

11794

b Department of Chemical and Molecular Engineering, Stony Brook University, Stony Brook, NY 11794

Abstract

The conversion of lignocellulosic biomass into fuels has been investigated as results of
increasing demand for petroleum oil and environmental concern. Furfuryl alcohol (FA), which is produced from furfural derived from a selective dehydration of xylose, is an attractive intermediate chemical for the production of template chemicals, such as levulinic acid and alkyl levulinate. During the formation of template chemicals, FA can be also converted to oligomer / polymer via dehydration under acidic conditions. To minimize the yield of oligomer/polymer
and maximize the yield of LA, fundamental understanding of undesired side reactions is required. The acid-catalyzed FA oligomer/polymerization has been studied in the liquid phase to identify the intermediate species and investigate the reaction mechanism. At room temperature, with a mineral acid (H2SO4) and Amberlyst 15 polymeric resin, FA monomer was vigorously converted into oligomer/polymers. A strong C=C and C=O bands observed in the Raman and IR spectra, respectively, provided the formation of a conjugated diene and diketone structure during the reaction. Based on the mass spectrometer data, FA monomer converted into a broad range of carbon number oligomers and three different dimer structures were observed; terminal CH2OH, ether bridged and methylene bridged dimer. In the case of metal oxide catalysts (Al2O3, ZrO2, TiO2, and Nb2O5), even at 100 oC, FA oligomerization was not observed, while WO3 can change the FA monomer color from yellow to red. It is suggested that small amount of FA monomer converted into oligomer over WO3 catalyst and the number of carbon can possibly be controlled.