2023 AIChE Annual Meeting
(633e) Assessing the Kinetics of Solid Waste Pyrolysis Under Catalytic and Non-Catalytic Conditions Using Thermogravimetric Analysis.
The disposal of solid waste through landfill and incineration poses a significant and costly challenge to global health, and results in the loss of a valuable resource for the circular economy. However, thermal pyrolysis of the organic components of MSW offers a scalable method for producing liquid fuels. In order to optimize this process, detailed knowledge of the associated thermochemistry and kinetics is required. This study utilizes thermogravimetric analysis (TGA) and kinetic modeling to analyze the catalytic and non-catalytic pyrolysis of a model solid waste feedstock containing cellulose, sucrose, sugarcane bagasse, and low-density polyethylene (LDPE). Results indicate that co-pyrolysis of biomass and plastic waste, with or without catalysts, occurs in four main stages. Non-catalytic MSW pyrolysis is influenced by sample heating rates but has little effect on the temperature or mass loss during each stage. In contrast, catalytic pyrolysis is sensitive to the catalyst:feedstock mass ratio, and kinetic analysis reveals a monotonic increase in activation energy for each stage of pyrolysis. However, energy barriers for individual stages decrease with increasing catalyst:feedstock ratio and are sensitive to the catalyst type. The study shows that TGA is an effective tool for catalyst selection and process optimization, provided that low heating rates are used. Catalyst selection plays a crucial role in reducing the energy required for the pyrolysis process, and the resulting products are of great importance in determining the economics of the process.