64 / 2023-05-31 18:43:21

Study on the Characteristics of Thermal Oxidation of Waterborne Polyurethane Paint Residue

waterborne polyurethane paint residue, solid waste, pyrolysis characteristics, oxidation characteristics, kinetic characteristics analysis.

We describe thermogravimetric analyses and pyrolysis kinetic studies carried out on waterborne polyurethane paint residue with extremely high volatile content. The effects of heating rate (10℃/min, 20℃/min, 30℃/min) and oxygen concentration (5%, 10%, 21%, 30%) on its weight loss characteristics and characteristic temperature were investigated and analyzed. Pyrolysis kinetic parameters were calculated by the Coats-Redfern method. The results show that: 1) There are two stages of pyrolysis of waterborne polyurethane paint residue. At 200~325℃ and 330~500℃. We find that with increasing heating rate the pyrolysis strength of waterborne polyurethane paint residue increases 2) There are two stages in the oxidation reaction, namely 150~300℃ and 320~460℃. The ignition index D and comprehensive combustion index S of waterborne polyurethane paint residue increase with the increase of heating rate, and increasing the heating rate can promote the oxidation reaction of waterborne polyurethane paint residue. 3) When the heating rate is constant at 20℃/min, increasing the oxygen concentration can promote the precipitation and combustion of volatile matter, in addition to the oxidation reaction at 21%O2 4) When increasing the heating rate, the activation energy of the pyrolysis reaction of waterborne polyurethane paint residue first increases and then decreases; the activation energy of the oxidation reaction is significantly reduced. 10%O2 is the optimal oxygen concentration for oxidation reaction. 5) There is a significant "kinetic compensation effect" between the activation energy E and frequency factor A of pyrolysis and oxidation reactions, with a fitting line InA=-0.98927+0.17735 ×E. This article provides a reference for studying the pyrolysis and oxidation characteristics of paint waste residue, and provides theoretical guidance for finding the optimal conditions for thermal treatment of solid waste from paint waste residue.