DefinePK

Abstract

This study investigated kinetics of hydrothermal carbonization (HTC) decomposition reaction of sugarcane bagasse treated with hot compressed water under varied temperature in range 200-300 °C. Experiments were carried out using a batch type reactor with a temperature controller. Characterization results showed that the decomposition reaction was influenced by temperature and reaction time. Degradation of hemicellulose's began at 200°C (3 min) and was completed at 240°C (5 min) to form arabinose and xylose. Cellulose started to decompose at 240°C (5 min) and was completely degraded at 270°C (20 min). Lignin decomposed at temperature range 200-300°C, and produced aromatic and phenolic compounds. The kinetics calculation for decomposition reactions such as hydrolysis and dehydration reactions are adopted as the heterogeneous reaction model. The model assumes that solid particle is cylindrical shape and this size is shrinking with reaction (cylindrical shrinking core model). Results of calculation indicated that the reaction is controlled with the diffusion through product layer. From these calculation and the results of decomposition mechanism can be explained as follows: (i) hydrothermal carbonization cellulose and hemicellulose's are decomposed preferentially and un-reacted lignin part to be diffusion layer. (ii) the hydrolysis and dehydration reaction started at 200ºC and 240ºC respectively and reaction rate increased with increasing temperature.