Co-pyrolysis characteristics and kinetic analysis of sewage sludge and peanut shells by TG-MS

• Published in: Journal of the Energy Institute 2024-10, Vol.116, p.101736, Article 101736
• Main Authors: Shen, Fang, Wen, Xiaoping, Lu, Can, Ojo, Abiodun Oluwaleke, Zhu, Yifei, Wu, Xiaoyong, Zhang, Weiwei
• Format: Article
• Language: English
• Subjects: Kinetics; Peanut shells; Pyrolysis; Sludge; Synergy; TG-MS
• ISSN: 1743-9671
• DOI: 10.1016/j.joei.2024.101736

This paper is a study on the pyrolysis characteristics and kinetics of sewage sludge, peanut shells, and their mixtures. The pyrolysis characteristics of sludge have been investigated by using TG-MS with different heating rates and peanut shell mixing ratios. The results indicate that reaction intensity increases with higher heating rates and the pyrolysis process occurs predominantly at higher temperature range. At a heating rate of 10 °C/min, sludge and peanut shells exhibited maximum pyrolysis weight loss of 48.32 % and 94.99 %, correspondingly. As the heating rate reduced, modifications in the heating rate exerted a more significant impact on the gas particles' current intensity. When the heating rate during the pyrolysis of peanut shells was elevated from 5 °C/min to 10 °C/min, the H2 particle current's intensity increased by a factor of 0.31 from 1.3 × 10-10 A to 1.7 × 10-10 A. During pyrolysis, a synergistic effect was observed in the mixture of sludge and peanut shells. The peanut shell mixing ratio that showed the highest synergistic pyrolysis effect was 40 wt%. An increase of 8.12 % in the maximum weight loss (TG) and 0.05 %/°C in the maximum weight loss rate (DTG) were check observed when compared to theoretical values. Additionally, the minimum activation energy needed for a sample to lose 1 % of its weight was only 0.323 kJ/mol. The higher the activation energy, the more significant the impact of the rate of warming was on the activation energy of the reaction. However, at low rates of temperature increase, the temperature rate increases a noteworthy impact on the activation energy necessary for the reaction. The optimization of the sludge-mixed peanut shell pyrolysis gasification process was supported by the theoretical reference and fundamental data available. In order to reduce the environmental burden of sludge treatment, biomass has been added to provide new solutions and ideas for sludge the reduction, and biomass reduction, resourcefulness and high-value utilization of sludge and biomass. •The pyrolysis of sewage sludge could be improved by blending peanut shells.•They're existed significant interaction between sludge and peanut shells.•The synergistic effect was strongest when the blending 40 % of peanut shells.•Blending peanut shells can reduce the activation energy of sludge pyrolysis.•Thermal hysteresis occurs in pyrolysis with increasing heating rate.