Behavior of 5-HMF in Subcritical and Supercritical Water

Our group studied the decomposition behavior of 5-hydroxymethylfurfural (5-HMF) in both subcritical and supercritical water. The experiments were performed in the temperature range of 175−450 °C at 25 MPa, with residence times ranging from 80 to 400 s. The decomposition of 5-HMF had Arrhenius characteristics, and the liquid product acted as an intermediate compound to form gas products of mainly CO2, CO, and H2. The decomposition behavior can be reasonably described by a first-order serial reaction. Though 5-HMF has been thought to reduce the carbon gasification efficiency in biomass conversion by initiating the formation of tar and char, the reaction of 5-HMF alone in water did not produce any detectable tar or char under our experimental conditions.