Physicochemical Characterization, Thermal Behavior, and Pyrolysis Kinetics of Sewage Sludge
Author:
Messaoudi Hanane12ORCID, Koukouch Abdelghani2ORCID, Bakhattar Ilias1, Asbik Mohamed1ORCID, Bonnamy Sylvie3ORCID, Bennouna El Ghali2, Boushaki Toufik4ORCID, Sarh Brahim4, Rouboa Abel5ORCID
Affiliation:
1. Thermal and Energy Research Team, Ecole Nationale Supérieure d’Arts et Métiers, Mohammed V University in Rabat, Rabat 10000, Morocco 2. Green Energy Park (IRESEN, UM6P), Ben Guerir 43150, Morocco 3. Laboratory of Confinement, Materials and Nanostructures (ICMN)-CNRS UMR7374, 45071 Orleans Cedex 2, France 4. Institute of Combustion, Aerothermal, Reactivity and Environment (ICARE)-CNRS UPR3021, 45071 Orléans Cedex 2, France 5. Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Abstract
Pyrolysis is an energy recovery technique with significant potential for managing wastewater treatment plant byproducts. This research aims to investigate the physicochemical and thermal properties of Moroccan sludge, as well as the behavior of its decomposition during pyrolysis at three different heating speeds (5, 10, and 20 K/min). Characterization of the sludge before pyrolysis through ultimate analysis, proximate analysis, FTIR spectroscopy, and XRD revealed that the sludge consists predominantly of organic matter, with a volatile matter rate of 48%, an ash rate of 37%, and a higher heating value (HHV) of 15 MJ/kg. The TGA-DTG curves identified four distinct stages in the sludge decomposition process: drying, decomposition of organic matter, degradation of calcium carbonate, and decomposition of inorganic matter. Using TG-MS analysis, the principal gases identified during pyrolysis were H2O, H2, CH4, CO2, CO, NO, and SO. The average activation energies (Ea) determined through kinetics models were found to be 413.4 kJ/mol for the Kissinger–Akahira–Sunose (KAS) model, 419.6 kJ/mol for the Flynn–Wall–Ozawa (FWO) model, and 416.3 kJ/mol for the Starink model. The values of Ea and the pre-exponential coefficient (A) obtained through the KAS, FWO, and Starink techniques are consistent with ΔG values ranging between 152 and 155 KJ/mol. The positive ΔS values range from 0.003 to 1.415 kJ/mol.K, indicating the complexity of the sludge response during pyrolysis and the spontaneity of the chemical reaction at high temperatures. The kinetic data obtained serves as a pillar for the development and improvement of sewage sludge pyrolysis systems, reinforcing their role in sustainable energy production.
Subject
Energy (miscellaneous),Energy Engineering and Power Technology,Renewable Energy, Sustainability and the Environment,Electrical and Electronic Engineering,Control and Optimization,Engineering (miscellaneous),Building and Construction
Reference57 articles.
1. Rijksdienst voor Ondernemend Nederland (2023, September 13). Business Opportunities Report for Reuse of Wastewater in Morocco Commissioned by the Netherlands Enterprise Agency. Available online: https://www.rvo.nl/sites/default/files/2018/06/Business-opportunities-report-for-reuse-of-wastewater-in-morocco.pdf. 2. The presence of contaminations in sewage sludge—The current situation;Fijalkowski;J. Environ. Manag.,2017 3. Effect of sewage sludge content on gas quality and solid residues produced by cogasification in an updraft gasifier;Seggiani;Waste Manag.,2012 4. Investigation du lessivage des stocks de boues d’épuration de Nador: Étude sur terrain et apport de l’expérimentation;Zerrouqi;J. Water Sci.,2012 5. Oladejo, J., Shi, K., Luo, X., Yang, G., and Wu, T. (2018). A Review of Sludge-to-Energy Recovery Methods. Energies, 12.
|
|