Investigation on Thermokinetic Study and Optimization of Sugarcane Bagasse Thermal Pyrolysis

Abstract

In this article, studies on kinetics and thermodynamics of sugarcane bagasse (SB) pyrolysis using thermogravimetric data have been carried out. The optimization of the process parameters involved in thermal pyrolysis was also investigated using a statistical technique called response surface methodology. The investigations on the physical properties of SB have revealed the presence of a high amount of volatile matter of about 79.54 wt% and less ash content of 3.02 wt% and a heating value of 18.27 MJ/kg. The thermogravimetric analysis of SB was performed at 5, 10, 15, and 20 °C/min heating rate under the inert atmosphere of nitrogen with a flow rate of 100 ml/min. The thermogravimetric studies have confirmed that the maximum degradation occurred in the temperature range of 200–500 °C. The kinetic parameters of SB pyrolysis at different heating rates were estimated by using Mampel’s first-order model-fitting method. The kinetic study has manifested an optimum activation energy value of 83.56 kJ/mol at 10 °C/min and a lower activation energy of 76.22 kJ/mol at 15 °C/min. The average activation energy of all the heating rates was obtained to be 79.04 kJ/mol. The thermodynamic studies affirmed an average ΔS value of − 150.27 J/K/mol, ΔH value of 73.819 kJ/mol, and ΔG value of 168.294 kJ/mol, respectively. The optimization studies showed that the maximum bio-oil yield was 43.02 wt% at optimum parameters such as the temperature of 500 °C, a nitrogen flow rate of 100 ml/min, and a heating rate of 20 °C/min, respectively. The gross calorific value and kinematic viscosity of the bio-oil obtained at optimum condition were found to be 34.02 MJ/kg and 14.20 cSt., respectively. It was also observed that the bio-oil obtained at optimum conditions contains a high amount of water of 23.70% attributing to a lesser calorific value of the bio-oil. Hence, it can be corroborated that the properties like water content, conradsons carbon residue, oxygen content, and kinematic viscosity need to be upgraded to make it a viable fuel source.