Horowitz-Metzger kinetic analysis of coconut shell waste combustion using thermogravimetric technique.

Coconut, as an evergreen plant, grows abundantly and generates coconut shell waste (CSW) as a by-product, often mistreated when it can be used as a renewable energy source. This research aims to study the kinetics of CSW combustion through thermogravimetric analysis (TGA). The sample was combusted from a temperature of around 27℃ to 1000 ° C at a constant heating rate of 30 ° C min-1 and an airflow rate of 100 ml min−1. The thermogravimetric (TG) and derivative thermogravimetric (DTG) curves show that the thermal decomposition of the CSW existed in three phases: from room temperature to 135 ° C occurred the release of moisture content, followed by a phase of active combustion in which cellulose and hemicellulose were decomposed and burned, and finally after the temperature of 550℃ was the solid residue decomposition occurred. The combustion kinetic parameters of CSW were evaluated using Horowitz-Metzger's integral method. The moisture content release phase possessed a lower activation energy value (80.99 kJ mol−1) compared to the main phase of the biomass combustion of CSW (127.80 kJ mol−1). Thermodynamic parameters were investigated as well, and it was revealed that a certain amount of heat was needed to decompose the CSW sample into an activated complex throughout the combustion reaction. [ABSTRACT FROM AUTHOR]