- Title
- Effects of brown coal fly ash on 30% monoethanolamine CO₂ capture systems
- Creator
- Chowdhury, Mohammad
- Date
- 2019
- Type
- Text; Thesis; PhD
- Identifier
- http://researchonline.federation.edu.au/vital/access/HandleResolver/1959.17/171010
- Identifier
- vital:14219
- Abstract
- Accumulation of fly ash during post-combustion capture (PCC) of CO2 is an emerging concern. This work assesses concerns that soluble ash components (e.g. Na, Ca, Mg) increase conductivity of amine systems increasing corrosion rates, and decreasing CO2 capture e ciency; slightly soluble metals ions (e.g. Fe) may catalyse amine oxidation; and insoluble ash components cause erosion and blockages in the PCC plants as well as providing catalytic surfaces. Loy Yang brown-coal y ashes (using XRD, SEM, EDS and ICP-MS) are rst characterised and separated into soluble, insoluble and char fractions. The e ect of each fraction on MEA oxidation (measured by UV-vis and organic acid formation) and corrosion is determined using lab-scale experiments in static and stirred pressurised reactors at simulated PCC stripper conditions. Fly ash was three times more soluble in severely oxidising conditions compared to mild 30% MEA extractions. Vantho te represents 10-20% of the y ash and was the main source of sodium, calcium and magnesium ions while Szmolnockite was a source of iron. Iron solubility was dependent on conditions, with 5% soluble in aqueous MEA and 10% in simulated desorber conditions. The soluble fraction was the only ash fraction to signi cantly promote MEA oxidation. Aged pall rings from a PCC pilot plant had severe grain boundary corrosion and chromiumoxide depletion. Grain boundary corrosion was less severe in pall rings under severely oxidising conditions. The e ects of soluble ash were unclear while organic acids promoted pitting. Fly ash is an important source of soluble sodium, calcium and iron into 30% MEA. The insoluble fraction had minimal impact on MEA oxidation and corrosion, suggesting that it was inert. Soluble ash fractions increased corrosion severity and promoted MEA oxidation. This work shows that deep y ash removal prior to PCC is particularly important for ashes with high solubility in the CO2 absorption system.; Doctor of Philosophy
- Publisher
- Federation University Australia
- Rights
- Copyright Mohammad Chowdhury
- Rights
- Open Access
- Rights
- This metadata is freely available under a CCO license
- Rights
- Was restricted access from 1/3/2020 for 18 months only
- Subject
- Loy Yang; Lignite; Chemical analysis; PCC
- Full Text
- Thesis Supervisor
- Vincent Verheyen
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