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dc.contributor.authorBourke, Jareden_NZ
dc.date.accessioned2007-02-22T15:27:11Z
dc.date.available2007-08-29T15:34:41Z
dc.date.issued2007en_NZ
dc.identifier.citationBourke, J. (2007). Preparation and Properties of Natural, Demineralized, Pure, and Doped Carbons from Biomass; Model of the Chemical Structure of Carbonized Charcoal. (Thesis, Master of Science (MSc)). The University of Waikato, Hamilton, New Zealand. Retrieved from https://hdl.handle.net/10289/2330en
dc.identifier.urihttps://hdl.handle.net/10289/2330
dc.description.abstractPioneering work performed by Rosalind Franklin over half a century ago provided the first structural models of two distinct carbon types: those that become graphitic during carbonization at high temperatures, and those that do not. Moreover it is known that certain properties of carbonaceous materials including combustion, surface area, electrical resistivity, and catalytic properties are influenced by mineral impurities. The nature of this division in biocarbon structure and the known effects of minerals on carbon properties have led to this work; three principal topics were addressed; (1) the investigation of the solid state structure of biocarbons derived from various biomass feedstocks, (2) the removal of inorganic minerals from biomass, and (3) the investigation of biocarbon electronic structure subsequent to doping with select inorganic minerals. Charcoals and carbonized charcoals (i.e. biocarbons) were prepared from a wide variety of biomass substrates, including pure sugars containing 5- and 6-membered rings with furanose and pyranose configurations, lignin, agricultural residues (corncob and nut shells) and a hard wood. These biocarbons were subject to proximate and elemental analysis, gas sorption analysis, and analysis by ICP-MS, SEM, XRD, ESR, 13C CPMAS NMR, and MALDI-TOF MS. All the carbonized charcoals contained oxygen heteroatoms, had high surface areas, and were excellent conductors of electricity. Doping the biocarbon with boron or phosphorus resulted in a slight improvement in its electrical conductivity. The XRD analysis indicated that the carbonized charcoals possess an aromaticity of about 71% that results from graphite crystallites with an average size of about 20 . The NMR analysis confirmed the highly aromatic content of the carbonized charcoals. The ESR signals indicated two major types of carbon-centered organic radicals. A number of techniques employed highlighted differences between carbonized charcoals and synthetic graphite but none more so than MALDI-TOF spectrometry. The biocarbons contained readily desorbed discrete ions with m/z values of 701, 685, 465, 453, 429, and 317. All of the above findings were used to develop a model for the structure of carbonized charcoal that is consistent with the biocarbon's oxygen content, microporosity and surface area, electrical conductivity, radical content, and its MALDI-TOF spectra. The removal of inorganic mineral constituents from various biomass feedstocks was achieved via simple washing/soaking techniques using two different aqueous media; deionized water and citric acid. The most effective and consistent demineralization treatment for removing minerals from biomass involved a hot 0.1 molL-1 citric acid percolation treatment, ca. 67% of inorganic mineral matter was removed. Mineral matter at the levels present in typical biomass derived charcoals and carbons had no significant influence upon the surface area or the electrical resistivity in carbonaceous materials after high heat treatment (950 C).en_NZ
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/zip
dc.language.isoen
dc.publisherThe University of Waikatoen_NZ
dc.rightsAll items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectFlash Carbonizationen_NZ
dc.subjectCharcoalen_NZ
dc.subjectCarbonen_NZ
dc.subjectCarbonized Charcoalen_NZ
dc.subjectBiomassen_NZ
dc.subjectDemineralizationen_NZ
dc.subjectDopingen_NZ
dc.subjectMALDI-TOF-MS.en_NZ
dc.titlePreparation and Properties of Natural, Demineralized, Pure, and Doped Carbons from Biomass; Model of the Chemical Structure of Carbonized Charcoal.en_NZ
dc.typeThesisen_NZ
thesis.degree.disciplineScience and Engineeringen_NZ
thesis.degree.grantorUniversity of Waikatoen_NZ
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (MSc)en_NZ
uow.date.accession2007-02-22T15:27:11Zen_NZ
uow.date.available2007-08-29T15:34:41Zen_NZ
uow.identifier.adthttp://adt.waikato.ac.nz/public/adt-uow20070222.152711en_NZ
uow.date.migrated2009-06-09T23:30:46Zen_NZ
pubs.place-of-publicationHamilton, New Zealanden_NZ


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