Stabilities of glucose in super/near-critical water or super/ near-critical methanol

The stabilities of glucose in various temperatures,pressures and residence times were studied.The experimental results indicated that high temperature decreased the stability of glucose.The selectivities of furfural derivatives,which were major byproducts by decomposition of glucose both in water and methanol,presented the maximum values with the increase of temperature.The pressures made little effects on the conversion of glucose in supercritical water at elevated temperature.In methanol,however,the conversion of glucose increased with the pressure and leveled off after the critical pressure.The yields of furfural derivatives both in water and in methanol reach the maxima in the vicinities of the critical pressures.The longer the residence time is,the higher the conversion rate of glucose either in supercritical water or in supercritical methanol.The yield and selectivity of furfural derivative in supercritical water decreased with the extension of residence time,meanwhile,the maximum yield and the selectivity of furfural derivative occurred.