Thermodynamics and Kinetics Parameters of Eichhornia crassipes Biomass for Bioenergy

Abstract

Background: Eichhornia crassipes is an aquatic plant well known for its role in soil reclamation due to the containment of valuable nutrients. Moreover, its biomass is an abundant and low-cost biological resource. Pyrolysis of a biomass offers one of the cleanest methods to harness the bioenergy stored in the biomass.

Objective: The present study was focused on evaluating the bioenergy potential of Eichhornia crassipes via pyrolysis.

Methods: Biomass of E. crassipes was collected from a municipal wastewater pond. Oven dried powdered biomass of E. crassipes was subjected to pyrolysis at three heating rates including 10, 30 and 50 °C min-1 in a simultaneous Thermogravimetry-Differential Scanning Calorimetry analyzer under an inert environment containing nitrogen. Data obtained were subjected to isoconversional models of Kissenger-Akahira-Sunose (KSA) and Flynn-Wall-Ozawa (FWO) to understand the reaction chemistry.

Results: Kinetic parameters have shown that the pyrolysis followed first-order reaction kinetics. The average values of activation energies (129.71-133.03 kJ mol-1) and thermodynamic parameters including high heating values (18.12 MJ kg-1), Gibb's free energies (171-180 kJ mol-1) and enthalpy of reaction (124-127 kJ mol-1) have shown the remarkable bioenergy potential of this biomass.

Conclusion: This low-cost biomass may be used to produce liquids, gases, and biochar in a costefficient and environmentally friendly way via pyrolysis or co-pyrolysis in the future.

Keywords: E. crassipes; Gibb's free energies; Low-cost biomass; TGA-DSC; bioenergy; pyrolysis..