Popovic, Nevena (2000) Physical and chemical characterization and upgrading of char derived from scrap tires by ultra fast pyrolysis. Masters thesis, Memorial University of Newfoundland.
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In the search for a commercially efficient technology for solving the problem of scrap tires, pyrolysis is accepted as an environmentally and economically attractive recycling method to recover useful products from scrap tire waste. Ireton International Waste Management is commercially developing an ultra fast pyrolysis technology called the Continuous Ablative Reactor (CAR) which can heat solid particles to a high temperature (500-600 °C) in under one second. The pyrolytic char obtained in this ultra fast pyrolysis process has been characterized and efforts were made to upgrade the product. EnerVision Inc. (Halifax) provided samples from their pilot unit. Initial investigations were focused on the char in its original form. The char contained inorganic compounds present in tires, along with the original carbon black and a substantial amount of condensed organic by-products formed during the pyrolysis process. The contaminants in the char were reflected in an oily appearance, specific odour and high ash content These contaminants can be eliminated, or significantly reduced. The economic feasibility of the process depends on the char quality and its usefulness in high value commercial applications. -- High temperature heat treatments (600-900 °C) and oxidation processes using various agents (i.e., air, H₂O₂, HNO₃) present an opportunity to elevate the char quality and improve its commercial value. In this study, it was demonstrated that the production of highly activated char is possible by activation using steam or carbon dioxide. The adsorption properties of the activated char so obtained were found to be comparable to those of the commercial active carbons. Hence, ultra fast pyrolysis may provide a recycling alternative for waste tires and for the production of new adsorbents from low-cost waste material. -- Analytical techniques used in characterizing the chars and activated chars (and described in this thesis) included flame atomic absorption, scanning electron microscopy, transmission electron microscopy, Malvern particle size counting, Raman spectroscopy, FT- infrared spectroscopy, N₂ and CO₂ adsorption studies, and sequential pyrolysis GC-MS.
|Item Type:||Thesis (Masters)|
|Additional Information:||Bibliography: leaves 100-106.|
|Department(s):||Science, Faculty of > Chemistry|
|Library of Congress Subject Heading:||Waste tires--Recycling; Pyrolysis; Char--Analysis|
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