Xylose Isomerization with Zeolites in a Two-Step Alcohol–Water Process

Marta Paniagua, Saravanamurugan Shunmugavel, Mayra Melián Rodriguez, Juan A Melero, Anders Riisager

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Isomerization of xylose to xylulose was efficiently catalyzed by large-pore zeolites in a two-step methanol–water process that enhanced the product yield significantly. The reaction pathway involves xylose isomerization to xylulose, which, in part, subsequently reacts with methanol to form methyl xyluloside (step 1) followed by hydrolysis after water addition to form additional xylulose (step 2). NMR spectroscopy studies performed with 13C-labeled xylose confirmed the proposed reaction pathway. The most active catalyst examined was zeolite Y, which proved more active than zeolite beta, ZSM-5, and mordenite. The yield of xylulose obtained over H-USY (Si/Al=6) after 1 h of reaction at 1008C was 39%. After water hydrolysis in the second reaction step, the yield increased to 47%. Results obtained from pyridine adsorption studies confirm that H-USY (6) is a catalyst that combines Brønsted and Lewis acid sites, and isomerizes xylose in alcohol media to form xylulose at low temperature. The applied zeolites are commercially available; do not contain any auxiliary tetravalent metals, for example, tin, titanium, or zirconium; isomerize xylose efficiently; are easy to regenerate; and are prone to recycling.
Original languageEnglish
JournalChemSusChem (Print)
Volume8
Issue number6
Pages (from-to)1088-1094
Number of pages7
ISSN1864-5631
DOIs
Publication statusPublished - 2015

Keywords

  • Alcohols
  • Heterogeneous catalysis
  • Isomerization
  • NMR spectroscopy
  • Zeolites

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