(403d) Impact of Feedstock Composition on Pyrolysis Kinetics and Product Distribution from Municipal Solid Waste

Thermochemical technologies can convert municipal solid waste (MSW) into energy-dense products, offering a reliable resource for energy recovery. In this study, three distinct MSW samples, plastic-rich, paper-rich, and whole paper blends, were analyzed using a thermogravimetric analyzer (TGA) in an inert (argon) atmosphere at four different heating rates (5, 10, 15, and 20 °C/min) up to 700 °C. Pyrolysis experiments were conducted in a drop tube reactor at 500 °C to investigate the impact of MSW composition on product distribution. The Flynn-Wall-Ozawa (FWO) isoconversional method and Criado's master plots were employed to determine kinetic triplets: apparent activation energy (E_a), pre-exponential factor (A), and kinetic model. The thermal degradation kinetics of these MSW samples exhibited distinct patterns. The plastic-rich MSW followed a single-stage three-dimensional diffusion D3 model (E_a = 256.68 kJ/mol, A = 9.3 x 10¹⁶ min^-1), while the paper-rich MSW followed a single-stage third-order F3 model (E_a = 169 kJ/mol, A = 5.2 x 10¹⁷ min^-1). The whole paper-rich MSW underwent a two-stage process, with a third-order F3 model (E_a = 201 kJ/mol, A = 1.8 x 10¹⁶ min^-1) followed by a one-dimensional diffusion D1 model (E_a = 241 kJ/mol, A= 4.9 x 10¹⁶ min^-1). The paper-rich and whole paper MSWs produced higher C₁-C₃ gas yields compared to the plastic-rich MSW. Tar analysis further indicated that the paper and whole paper-rich MSWs predominantly produced oxygenated hydrocarbons, whereas the plastic-rich MSW exhibited a higher proportion of aliphatic hydrocarbons. These results enhance understanding of MSW pyrolysis mechanisms and product distribution, promoting efficient waste conversion and energy solutions.