Co-pyrolysis of sewage sludge and waste tobacco stem: Gas products analysis, pyrolysis kinetics, artificial neural network modeling, and synergistic effects

Chaowei Ma; Fengxia Zhang; Jianhang Hu; Hua Wang; Shiliang Yang; Huili Liu

doi:10.1016/j.biortech.2023.129816

Co-pyrolysis of sewage sludge and waste tobacco stem: Gas products analysis, pyrolysis kinetics, artificial neural network modeling, and synergistic effects

Bioresour Technol. 2023 Dec:389:129816. doi: 10.1016/j.biortech.2023.129816. Epub 2023 Oct 2.

Authors

Chaowei Ma¹, Fengxia Zhang², Jianhang Hu³, Hua Wang¹, Shiliang Yang⁴, Huili Liu⁴

Affiliations

¹ Engineering Research Center of the Ministry of Education for Metallurgical Energy Conservation and Emission Reduction, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; Southwest United Graduate School, Kunming 650092, Yunnan Province, PR China.
² Engineering Research Center of the Ministry of Education for Metallurgical Energy Conservation and Emission Reduction, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; Kunming Metallurgy College, Kunming 650033, Yunnan Province, PR China.
³ Engineering Research Center of the Ministry of Education for Metallurgical Energy Conservation and Emission Reduction, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; Southwest United Graduate School, Kunming 650092, Yunnan Province, PR China. Electronic address: hujh51@126.com.
⁴ Engineering Research Center of the Ministry of Education for Metallurgical Energy Conservation and Emission Reduction, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China; State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming 650093, Yunnan Province, PR China.

PMID: 37793553
DOI: 10.1016/j.biortech.2023.129816

Abstract

This research comprehensively investigates the co-pyrolysis of sewage sludge (SS) and waste tobacco stem (WTS). Various SS and WTS ratios (1:0, 0.75:0.25, 0.50:0.50, 0.25:0.75, and 0:1) were tested over a range of heating rates (30 °C to 800 °C). Apparent activation energies were calculated using model-free methods, and the co-pyrolysis mechanism was described with the master plot method. Results suggest that SS and WTS co-pyrolysis follows power-law models (P3, P4). Among blends, S75W25 exhibited optimal synergy, with the lowest activation energy required for the pyrolysis reactions and inhibits CO₂ emissions. S75W25's pyrolysis gas primarily contained acids (e.g., ethylxanthogenacetic acid, acetic acid), hydrocarbons (e.g., supraene, cyclopropyl carbinol), and other compounds (e.g., CO₂, pyrazine, pyridine, indole). ANN was utilized to forecast the temperature-mass loss relationships in co-pyrolysis, with the optimal model being ANN21, yielding a high correlation coefficient (R² = 0.99999). This study offers guidance for the efficient utilization of waste SS and WTS.

Keywords: Artificial neural network; Co-pyrolysis; Kinetics; Sewage sludge; Waste tobacco stem.

MeSH terms

Carbon Dioxide
Kinetics
Neural Networks, Computer
Nicotiana*
Pyrolysis
Sewage*

Substances

Sewage
Carbon Dioxide