The occurrence of temperatures in municipal solid waste (MSW) landfill gas (LFG) extraction systems in excess of 55°C is a problem that has gained much attention in the solid waste industry, both domestically and globally. Facilities which frequently experience such temperatures are termed Elevated Temperature Landfills (ETLFs), and recent research conducted at the University of Central Florida (UCF) has provided strong evidence that ash, both MSW incinerator ash (MSWIA) and coal combustion ash (CCA), when co-disposed with unburned MSW, provides materials which are able to participate in abiotic exothermic reactions that may lead to the development or sustainment of ETLFs. These reactions include ash hydration and carbonation, as well as the oxidation and corrosion of metals commonly found in ash. Over the course of this project, sixteen ash samples from across the U.S. were analyzed (ten MSWIAs and six CCAs) using spectroscopic and thermal analyses. X-ray diffraction (XRD), x-ray fluorescence (XRF), and scanning electron microscopy coupled with x-ray dispersive elemental spectroscopy (SEM/XEDS) provided insight into ash compositions, while thermal gravimetric analysis (TGA) shed light into the sensitivity of ashes to changes in temperature. Results from this project reveal that the high-temperature incineration of MSW and coal feedstocks, as well as weathering processes impacting these ashes, yields a heterogenous material with many complex mineral and glassy phases. A simple heat-generation equation was developed and, using ash compositions obtained via XEDS, a value termed relative heat potential (RHP) was calculated for each sample. Results show that CCAs may be expected to generate roughly 15% more heat than MSWIAs when deposited in landfills, likely due to their greater aluminum content.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd2020-1780 |
| Date | 01 January 2021 |
| Creators | Villarruel-Moore, Angel |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations, 2020- |
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