Co-pyrolysis of Sewage Sludge with Paint Sludge: Kinetics and Thermodynamic Analysis via Iso-conversional Methods

This study explored the synergistic interaction of sewage sludge (SS) and automotive paint sludge (PS) during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems, utilizing thermogravimetric analysis (TGA) and thermogravimetric-mass spectrometry (TGA-MS). The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS. The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS, while the main source of the antagonistic effect is that, during the mechanical mixing process, the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect, hindering the volatilization of volatile components. SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas. This study will provide some in-depth insights into the co-pyrolysis of SS/PS, and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns.