Combustion behaviour of palm kernel shell torrefied by mild pressurization technique.

Abstract

Continuous supply of the costly inert gas such as nitrogen during torrefaction is undesirable due to cost burden in terms of operational cost. Therefore, mild pressurization technique is introduced to eliminate completely the dependence on inert gas for producing solid biofuel for power generation. In the present study, the combustion behaviour of torrefied palm kernel shell (PKS) was investigated by using Thermogravimetric Analyzer (TGA) under temperature range of 30 to 900°C, heating rate of 10 and 30 °C/min, and oxygen flow rate of 20 ml/min. The used PKS has been torrefied by the mild pressurization technique for various residence times of 30 to 90 minutes and temperature of 300°C. Based on the thermogravimetry (TG) and derivative thermogravimetry (DTG) curves, it was found that the ignition temperature of the torrefied samples ranges from 276 to 285°C while the burnout temperature ranges from 476 to 482°C. For the PKS torrefied with longer residence time, the total percentage of mass loss during combustion stage becomes less. Finally, when the heating rate for TGA is changed from 10 to 30°C/min, almost same TG and DTG curves were obtained.