Biomass and Municipal Solid Waste (MSW) Pyrolysis in a Bench-scale Drop Tube Reactor
Date
2023-05-30
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Abstract
Biomass pyrolysis has been recognized as a promising solution to address the challenges of energy demand and solid waste treatment in a renewable manner. However, the complexity of the process has limited the understanding of the link between theoretical modeling and engineering data, and commercial reactors are not yet available in the market. This thesis investigates the effect of biomass pyrolysis controlling parameters on a bench-scale drop tube reactor (DTR) and analyzes the behavior of a biomass-MSW mixture in TGA and DTR.
The study aims to achieve three main objectives: (1) to modify the bench-scale DTR to enhance its efficiency, (2) to investigate the effects of temperature, carrier gas (N2) flow rate, and feedstock particle sizes on product yield and composition, and (3) to analyze the behavior of a biomass-MSW mixture in TGA and DTR reactions. To achieve these objectives, a series of experiments were conducted, and the products were analyzed for properties such as heating value, moisture, chemical composition, and yield. The results indicate that poor heat transfer limits the efficiency of the reaction, resulting in low liquid yields of 10-25%. The optimal reaction temperature is found to be around 500°C, as temperatures below this value result in unreacted biomass, while temperatures higher than 600°C led to gasification and the production of more syngas than bio-oil. An increase in nitrogen flowrate can improve heat transfer, but it also reduces the time for product condensation and collection. Smaller feedstock particles (<125 μms) are less affected by heat transfer issues, but they tend to agglomerate, which reduces bio-oil yield. The study also found that a temperature higher than 500°C is required to fully convert MSW mixtures. The study proposes several recommendations to address the heat transfer issue, including decreasing the reactor diameter, increasing the reactor length, and preheating the nitrogen flow to 400-500°C before it enters the reactor. Overall, the findings of this study have significant implications for the development of biomass pyrolysis technology and provide insights into the design and optimization of pyrolysis reactors for efficient and sustainable energy production and waste management.
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Keywords
Pyrolysis, Municipal solid waste, bio-oil, biofuel, renewable energy
Citation
He, C. (2023). Biomass and municipal solid waste (MSW) pyrolysis in a bench-scale drop tube reactor (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.