https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:51243 Wed 06 Mar 2024 15:07:20 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:50414 2CO₃: 43.5%, Na₂CO₃: 31.5%, K₂CO₃: 25%) during slow temperature ramping rates (5 °C/min) under N₂ at temperatures above 750 °C. Initial findings suggest that approximately 50 wt% of graphite experiences interlayer expansion. The conventional d spacing of 0.34 nm is modified to a range of intervals between 0.41 nm and 1.22 nm. As a consequence of high operational temperature (800 °C), cations (Li⁺, Na⁺ and K⁺) as well as potentially the anion (CO₃²–) intercalate between graphitic layers and overcome Van der Waal force between layers. Employing a pressurized N₂ environment of 5 bar and 10 bar successfully controls carbonate vaporization and decomposition, as well as inducing ordered layer manipulation to exfoliate more graphite planes from the edges towards deeper levels of the particles. Exploring parameters of both carbonate loading and treatment time in addition to pressure demonstrate that this work opens up a rich selection of parameters that can be used to produce carbons with tuned properties from graphite.]]> Tue 25 Jul 2023 17:58:35 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45721 Mon 29 Jan 2024 18:37:58 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:40921 Mon 29 Jan 2024 17:48:04 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:44056 2CO₃: 43.5%, Na₂CO₃: 31.5%, K₂CO₃: 25% mol), subjected to two different higher heating temperatures (350 °C and 600 °C). It is shown here that the addition of a carbonate eutectic affects char-making reactions through: tar generation modification, changes in the emitted volatile molecules, alteration of surface oxygenate bonds as well as transformation in the morphology of the remnant char. Initial results using Differential Thermal Gravimetric Analysis (DTG) show that, in carbonate treated samples, char yield is increased at both temperatures investigated. In treated cellulose, a reduced temperature onset of mass loss is observed, expected to be from modified depolymerisation and inhibition of levoglucosan formation for samples heated to both 350 °C and 600 °C. Gas analysis by micro-GC proves that carbonate is involved in the cracking of condensable volatiles, which generates a highly porous char structure and increases the emission of non-condensable volatiles. In addition, SEM results for carbonate treated cellulose demonstrate extensive pore generation including both surface and internally generated pores and interconnected tunnel-like structures at higher temperature (600 °C). This was not reflected however in BET results due to the melted salt blocking the available internal porous structure. Improvement in BET results for chars produced at 600 °C was regardless seen on carbonate addition in both biomass (improving from 371 m² g⁻¹ to 516 m² g⁻¹) and lignin (improving from 11 m² g⁻¹ to 209 m² g⁻¹).]]> Mon 29 Jan 2024 17:46:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46145 Eucalyptus pilularis biomass and ternary molten carbonate eutectic [Li₂CO₃, 43.5%; Na₂CO₃, 31.5%; and K₂CO₃, 25% (mole percentage)] in thermogravimetric analysis at three different temperatures, 600, 750, and 900 °C, was studied. These salts affect the slow pyrolysis process, including changes in the volatile release mechanism and the morphology of remnant char material. The initial results show that, in the presence of molten carbonate, biomass particles make bubble-shaped larger particles, which result in less volatile emissions and more char residue. It is suggested that the ternary eutectic has a chemical diluent and catalytic role, particularly in the case of higher salt doping. Results from scanning electron microscopy images give strong evidence that molten carbonates capture volatiles inside swelling carbon particles, which causes the generation of various sizes of pores as well as char-making reactions, and at a higher temperature, the bubble-shaped particles will rupture. Swelling of this nature has previously only been observed clearly in coal precursors; however, this is the first observation in a biomass-based system. Also, at a temperature above 750 °C, decomposition of molten carbonate generates CO₂ and carbon/carbonate gasification produces CO as well as a more “activated” biochar.]]> Fri 11 Nov 2022 18:31:02 AEDT ]]>