Effect of heating rate on liquefaction of cellulose by hot compressed water

The effect of heating rate on the liquefaction of a microcrystalline cellulose particle was investigated by using a batch type reactor with a temperature controller. Experiments were carried out over the temperature range of 443–553 K. The temperature profile of the heating was controlled to obtain a proportional relationship with time. Heating rates ranged from 0.0167 to 0.167 K/s. The resulting concentration profiles of cellulose, oligosaccharides, monosaccharides and pyrolysis products were analyzed using a theoretical model which considered temperature variation during the reaction. The calculated results exhibit a reasonable fit to the experimental data. The predicted cellulose concentration profiles over a wide range of heating rates indicate that liquefaction of cellulose is affected when the heating rate is below 1 K/s. It is concluded that consideration of the heating process is necessary in the modeling of liquefaction when using reactors which cannot achieve fast heating.