Exploration of the bioenergy potential of Dactyloctenium aegyptium through pyrolysis, kinetics, and thermodynamic parameters to produce clean fuels and biochemicals

Abstract

The Egyptian grass (Dactyloctenium aegyptium) is a common low-cost coarse grass which is adapted to poor soils. The biomass of the Egyptian grass may be used to produce cleaner and sustainable fuels through pyrolysis without causing any contradictory impact on the land for food. It is profound to understand the thermochemical character of the Egyptian grass biomass for its efficient thermal conversion to clean fuels and chemicals. The current study elucidated the pyrolysis process of this biomass for the very first time based on the pyrolysis data. Heat-dried powdered biomass of Dactyloctenium aegyptium was pyrolyzed at 10 min−1, 30 min−1 and 50 °C min−1 in a simultaneous Thermogravimetry–Differential Scanning Calorimetry analyzer (TGA-DSC) under nitrogen atmosphere. Isoconversional models of Kissenger-Akahira-Sunose (KSA), Flynn–Wall–Ozawa (FWO) and first and second order reaction kinetics model were used to analyze the pyrolytic kinetic parameters. The pyrolysis of D. aegyptium grass biomass was shown to be a three-stage pyrolysis process where around 50 % of the product formation was happening within a narrow temperature range of 240–360 °C with the Activation energies ranged from 167 to 267 kJ mol−1 and thermodynamic parameters including 18.25–18.63 MJ kg−1 of high heating values, 169–177 kJ mol−1 of Gibb’s free energies, and 166–256 kJ mol−1 of reaction enthalpy have shown the outstanding pyrolysis and co-pyrolysis potential of Egyptian grass to produce clean fuels.