Dehydration of xylose to furfural using a Lewis or Brönsted acid catalyst and N2 stripping

The activity of Lewis (Nb2O5) and Brönsted (Amberlyst 70) acid catalysts for the cyclodehydration of xylose to furfural was studied. The nature of the acidity resulted in significant changes in the reaction mechanism. Lewis acid sites promote the formation of xylulose, while Brönsted acid sites are required to further dehydrate the sugar to furfural. Amberlyst 70 in water/toluene at 175 °C showed lower activity but gave a higher furfural yield. Using N2 as the stripping agent considerably improved the furfural yield and product purity in the stripped stream. Catalyst stability was also studied.

Graphical abstractThe present work studied the change of the xylose dehydration mechanism and furfural yield using Lewis (Nb2O5/Cabosil) or Brönsted (Amberlyst 70) acid catalysts in combination with simultaneous discontinuous N2-stripping.Figure optionsDownload full-size imageDownload as PowerPoint slide