Selective dehydration of different substrates, such as fructose, sucrose and inulin, to 5-hydroxymethyl-2-furaldehyde has been studied in aqueous medium by using heterogeneous niobium-based catalysts. Batch experiments have been performed in the presence of both commercial niobium phosphates and catalysts prepared by treatment of niobic acid with phosphoric acid. Flow experiments on catalyst packed beds have been also examined. Finally, batch catalytic experiments, characterized by combination of reaction and products extraction steps, have been also carried out.