Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.

Bibliographic Details
Main Author: Hunt, Anton (Anton Stuart)
Other Authors: Ahmed F. Ghoniem.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2015
Subjects:
Online Access:http://hdl.handle.net/1721.1/100059
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author Hunt, Anton (Anton Stuart)
author2 Ahmed F. Ghoniem.
author_facet Ahmed F. Ghoniem.
Hunt, Anton (Anton Stuart)
author_sort Hunt, Anton (Anton Stuart)
collection MIT
description Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.
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spelling mit-1721.1/1000592019-04-10T23:12:26Z Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis Hunt, Anton (Anton Stuart) Ahmed F. Ghoniem. Massachusetts Institute of Technology. Department of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering. Mechanical Engineering. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015. This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Cataloged from student-submitted PDF version of thesis. Includes bibliographical references. Ion transport membranes (ITMs) are dense ceramic membranes which have the potential for 100% selective separation of oxygen from air. ITMs operate at extreme temperatures (>800°C), necessary for the mobility of lattice oxygen ions: this can result in significant experimental challenges. Specifically, the local gas compositions at both the high oxygen (air) and low oxygen (sweep) surfaces influence the oxygen flux: these experimental measurements have not been available until now. A novel ITM research reactor has thus been developed which can directly sample gases at the membrane surface at high temperature flux conditions. This ITM reactor has been scaled up to allow for gas-probing instruments to be used without overly disrupting the experimental flowfield. The ITM stoichiometry investigated in this study is La₀.₉9Ca₀.₁1FeO3-[delta] (LCF), and has been chosen for its chemical stability attributes and consequent applicability to industry. Two modes of operation have been investigated using the LCF ITM in the reactor: inert (using CO₂ sweep gas to carry away an oxygen-enriched stream) and reactive (using CO₂:CH₄ sweep gas resulting in fuel reactions with the permeating oxygen). There is a huge advantage to running ITMs reactive: the oxygen flux can be enhanced by an order of magnitude or more, whilst useful fuel synthesis reactions can be actively enhanced by the catalytic ITM surface. This study therefore utilizes the local measurement capabilities of the novel ITM reactor to develop a physical understanding through oxygen flux models for both modes of operation: inert and reactive. Both flux models enable the prediction of the oxygen lux with the operating conditions necessary as input parameters. They are therefore useful tools for future optimization of ITM reactor designs. Further insight using the flux models is also provided. The inert flux model is used to determine the surface oxygen vacancy concentration which drives the oxygen flux. The reactive flux model is used in preliminary numerical simulations of ITM reactors to produce flux performance maps based on the input operating conditions. by Anton Hunt. Ph. D. 2015-12-03T18:46:27Z 2015-12-03T18:46:27Z 2015 2015 Thesis http://hdl.handle.net/1721.1/100059 929653178 eng M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 237 pages application/pdf Massachusetts Institute of Technology
spellingShingle Mechanical Engineering.
Hunt, Anton (Anton Stuart)
Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
title Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
title_full Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
title_fullStr Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
title_full_unstemmed Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
title_short Experimental investigations of oxygen-separating ion transport membranes for clean fuel synthesis
title_sort experimental investigations of oxygen separating ion transport membranes for clean fuel synthesis
topic Mechanical Engineering.
url http://hdl.handle.net/1721.1/100059
work_keys_str_mv AT huntantonantonstuart experimentalinvestigationsofoxygenseparatingiontransportmembranesforcleanfuelsynthesis