{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/300813"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/300813","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Evaluating new Oxygen Transfer Materials for Air Separation, Oxy-Fuel Combustion and other Processes","abstract":"Chemical looping air separation was the pre-dominant commercial process to produce oxygen until it was superseded by the Hampson-Linde cycle in the early $20^{th}$ century. A chemical air separation loop is characterised by the cyclic reduction and oxidation of solid material serving as an oxygen carrier, which has the capacity to release gas phase oxygen. At the time, the so-called Brin process suffered from the deactivation of the oxygen carrier material due to carbonation if the air was not pre-treated. In the past decade, however, the process has gained considerable attention due to advances in material science. The objective of this Dissertation is to suggest novel materials suitable for this air separation process. In this Dissertation, the entire process from the identification of, in theory, suitable oxygen transfer materials $via$ the synthesis and evaluation (regarding thermochemical properties) of these materials through to the investigation of the kinetic parameters and stability over many redox cycles is carried out. Although oxygen is an important industrial gas used for many applications, here, chemical looping air separation is investigated as a method of avoiding the emission of CO$_2$ from a power plant $via$ oxy-fuel combustion and subsequent CO$_2$ capture. First, a fully heat integrated model of a power station, linked to a model of chemical looping air separation system is developed to back calculate the thermochemical properties, $i.e.$ enthalpy ($\\Delta H_{r,298K}^{o}$) entropy ($\\Delta S_{r,298K}^{o}$) reaction, of the oxygen carrier required for efficient operation. It is demonstrated that an oxy-fuel steam power plant fed with oxygen from chemical looping air separation can be operated with an energy penalty of as low as 1.5 percentage points. However, this is only possible for materials possessing a narrow range of $\\Delta H_{r,298K}^{o}$ and $\\Delta S_{r,298K}^{o}$. From a list of oxygen carriers possessing favourable thermodynamic properties, the perovskite SrFeO$_{3-\\delta}$ is selected for further investigation. In a tubular micro-reactor, developed and optimised for minimum noise and response time, oxygen transfer capacities and reaction kinetics of the pure, Mn-doped and Co-doped SrFeO$_{3-\\delta}$ are investigated. The rate constants of the reduction reaction have been successfully extracted, however, this was not possible for the oxidation which proceeded too rapidly. The apparent activation energy, $E_{a,app}$, the pre-exponential factor, $A'$, for SrFeO$_{3-\\delta}$, SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$, SrCo$_{0.4}$Fe$_{0.6}$O$_{3-\\delta}$ are 128.9, 45.3 and 271.3 kJ/mol, and 3.9$\\cdot$10$^{5}$, 6.29 and 35.5$\\cdot$10$^{12}$ mol/s/Pa/m$^3$, respectively. SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$ showed both the highest oxygen transfer capacity and rate of reduction and SrCo$_{0.4}$Fe$_{0.6}$O$_{3-\\delta}$ the lowest; around 325 and 117 $\\mu$mol of O$_2$ per gram of oxygen carrier material at 898 K, respectively. When subjecting SrFeO$_{3-\\delta}$ and SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$ to 1000 redox cycles, both showed an increase in the maximum observed rate of reduction and the oxygen transfer capacity.","abstract_html":"Chemical looping air separation was the pre-dominant commercial process to produce oxygen until it was superseded by the Hampson-Linde cycle in the early 20th century. A chemical air separation loop is characterised by the cyclic reduction and oxidation of solid material serving as an oxygen carrier, which has the capacity to release gas phase oxygen. At the time, the so-called Brin process suffered from the deactivation of the oxygen carrier material due to carbonation if the air was not pre-treated. In the past decade, however, the process has gained considerable attention due to advances in material science. The objective of this Dissertation is to suggest novel materials suitable for this air separation process. In this Dissertation, the entire process from the identification of, in theory, suitable oxygen transfer materials $via$ the synthesis and evaluation (regarding thermochemical properties) of these materials through to the investigation of the kinetic parameters and stability over many redox cycles is carried out. Although oxygen is an important industrial gas used for many applications, here, chemical looping air separation is investigated as a method of avoiding the emission of CO2 from a power plant $via$ oxy-fuel combustion and subsequent CO2 capture. First, a fully heat integrated model of a power station, linked to a model of chemical looping air separation system is developed to back calculate the thermochemical properties, $i.e.$ enthalpy (\\Delta Hr,298Ko) entropy (\\Delta Sr,298Ko) reaction, of the oxygen carrier required for efficient operation. It is demonstrated that an oxy-fuel steam power plant fed with oxygen from chemical looping air separation can be operated with an energy penalty of as low as 1.5 percentage points. However, this is only possible for materials possessing a narrow range of \\Delta Hr,298Ko and \\Delta Sr,298Ko. From a list of oxygen carriers possessing favourable thermodynamic properties, the perovskite SrFeO3-δ is selected for further investigation. In a tubular micro-reactor, developed and optimised for minimum noise and response time, oxygen transfer capacities and reaction kinetics of the pure, Mn-doped and Co-doped SrFeO3-δ are investigated. The rate constants of the reduction reaction have been successfully extracted, however, this was not possible for the oxidation which proceeded too rapidly. The apparent activation energy, Ea,app, the pre-exponential factor, $A'$, for SrFeO3-δ, SrMn0.1Fe0.9O3-δ, SrCo0.4Fe0.6O3-δ are 128.9, 45.3 and 271.3 kJ/mol, and 3.9$\\cdot$105, 6.29 and 35.5$\\cdot$1012 mol/s/Pa/m3, respectively. SrMn0.1Fe0.9O3-δ showed both the highest oxygen transfer capacity and rate of reduction and SrCo0.4Fe0.6O3-δ the lowest; around 325 and 117 μmol of O2 per gram of oxygen carrier material at 898 K, respectively. When subjecting SrFeO3-δ and SrMn0.1Fe0.9O3-δ to 1000 redox cycles, both showed an increase in the maximum observed rate of reduction and the oxygen transfer capacity.","abstract_has_math":true,"creators":["Goerke, Richard Hinrich"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Scott, Stuart Ashley"],"committee_chairs":[],"committee_members":[],"year":2020,"date_issued":"2020-04-25","date_published":"2020-04-25","updated_at":"2026-07-22T22:24:20Z","subjects":["Chemical looping","Air separation","Oxygen Production","Carbon Capture","CCS","Clean Coal","Perovskites","Oxygen Carrier"],"languages":["en"],"rights":["Fig. 1-2, Concept of chemical looping air separation, copyright holder is Elsevier, copyright license number 4726390207289 Fig. 4-3, Phase diagram of Sr-Fe-O under 1 bar of nitrogen, copyright holder is Elsevier, copyright license number 4726391446039"],"rights_urls":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/e9db0b31-df02-46bd-8f88-0102d8f63d34/download","https://creativecommons.org/licenses/by-nc/4.0/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.47887","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Scott, Stuart Ashley"]},{"key":"dc:creator","label":"Author","values":["Goerke, Richard Hinrich"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2020-04-25"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/300813"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemical looping","Air separation","Oxygen Production","Carbon Capture","CCS","Clean Coal","Perovskites","Oxygen Carrier"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/e9db0b31-df02-46bd-8f88-0102d8f63d34/download","https://creativecommons.org/licenses/by-nc/4.0/","Fig. 1-2, Concept of chemical looping air separation, copyright holder is Elsevier, copyright license number 4726390207289 Fig. 4-3, Phase diagram of Sr-Fe-O under 1 bar of nitrogen, copyright holder is Elsevier, copyright license number 4726391446039"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["10.17863/CAM.47887"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/2ee74558-a6f2-434a-a66c-74098fbc8bc5/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Chemical looping air separation was the pre-dominant commercial process to produce oxygen until it was superseded by the Hampson-Linde cycle in the early $20^{th}$ century. A chemical air separation loop is characterised by the cyclic reduction and oxidation of solid material serving as an oxygen carrier, which has the capacity to release gas phase oxygen. At the time, the so-called Brin process suffered from the deactivation of the oxygen carrier material due to carbonation if the air was not pre-treated. In the past decade, however, the process has gained considerable attention due to advances in material science. The objective of this Dissertation is to suggest novel materials suitable for this air separation process. In this Dissertation, the entire process from the identification of, in theory, suitable oxygen transfer materials $via$ the synthesis and evaluation (regarding thermochemical properties) of these materials through to the investigation of the kinetic parameters and stability over many redox cycles is carried out. Although oxygen is an important industrial gas used for many applications, here, chemical looping air separation is investigated as a method of avoiding the emission of CO$_2$ from a power plant $via$ oxy-fuel combustion and subsequent CO$_2$ capture. First, a fully heat integrated model of a power station, linked to a model of chemical looping air separation system is developed to back calculate the thermochemical properties, $i.e.$ enthalpy ($\\Delta H_{r,298K}^{o}$) entropy ($\\Delta S_{r,298K}^{o}$) reaction, of the oxygen carrier required for efficient operation. It is demonstrated that an oxy-fuel steam power plant fed with oxygen from chemical looping air separation can be operated with an energy penalty of as low as 1.5 percentage points. However, this is only possible for materials possessing a narrow range of $\\Delta H_{r,298K}^{o}$ and $\\Delta S_{r,298K}^{o}$. From a list of oxygen carriers possessing favourable thermodynamic properties, the perovskite SrFeO$_{3-\\delta}$ is selected for further investigation. In a tubular micro-reactor, developed and optimised for minimum noise and response time, oxygen transfer capacities and reaction kinetics of the pure, Mn-doped and Co-doped SrFeO$_{3-\\delta}$ are investigated. The rate constants of the reduction reaction have been successfully extracted, however, this was not possible for the oxidation which proceeded too rapidly. The apparent activation energy, $E_{a,app}$, the pre-exponential factor, $A'$, for SrFeO$_{3-\\delta}$, SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$, SrCo$_{0.4}$Fe$_{0.6}$O$_{3-\\delta}$ are 128.9, 45.3 and 271.3 kJ/mol, and 3.9$\\cdot$10$^{5}$, 6.29 and 35.5$\\cdot$10$^{12}$ mol/s/Pa/m$^3$, respectively. SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$ showed both the highest oxygen transfer capacity and rate of reduction and SrCo$_{0.4}$Fe$_{0.6}$O$_{3-\\delta}$ the lowest; around 325 and 117 $\\mu$mol of O$_2$ per gram of oxygen carrier material at 898 K, respectively. When subjecting SrFeO$_{3-\\delta}$ and SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$ to 1000 redox cycles, both showed an increase in the maximum observed rate of reduction and the oxygen transfer capacity."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["69de4e5ffd40805a205c0199a2dd392c","87eda9de84448d1f82354d60eee3eb5f"]},{"key":"dc:title","label":"Title","values":["Evaluating new Oxygen Transfer Materials for Air Separation, Oxy-Fuel Combustion and other Processes"]}]}],"canonical_facts":{"dc:contributor.advisor":["Scott, Stuart Ashley"],"dc:creator":["Goerke, Richard Hinrich"],"dc:date.issued":["2020-04-25"],"dc:description.abstract":["Chemical looping air separation was the pre-dominant commercial process to produce oxygen until it was superseded by the Hampson-Linde cycle in the early $20^{th}$ century. A chemical air separation loop is characterised by the cyclic reduction and oxidation of solid material serving as an oxygen carrier, which has the capacity to release gas phase oxygen. At the time, the so-called Brin process suffered from the deactivation of the oxygen carrier material due to carbonation if the air was not pre-treated. In the past decade, however, the process has gained considerable attention due to advances in material science. The objective of this Dissertation is to suggest novel materials suitable for this air separation process. In this Dissertation, the entire process from the identification of, in theory, suitable oxygen transfer materials $via$ the synthesis and evaluation (regarding thermochemical properties) of these materials through to the investigation of the kinetic parameters and stability over many redox cycles is carried out. Although oxygen is an important industrial gas used for many applications, here, chemical looping air separation is investigated as a method of avoiding the emission of CO$_2$ from a power plant $via$ oxy-fuel combustion and subsequent CO$_2$ capture. First, a fully heat integrated model of a power station, linked to a model of chemical looping air separation system is developed to back calculate the thermochemical properties, $i.e.$ enthalpy ($\\Delta H_{r,298K}^{o}$) entropy ($\\Delta S_{r,298K}^{o}$) reaction, of the oxygen carrier required for efficient operation. It is demonstrated that an oxy-fuel steam power plant fed with oxygen from chemical looping air separation can be operated with an energy penalty of as low as 1.5 percentage points. However, this is only possible for materials possessing a narrow range of $\\Delta H_{r,298K}^{o}$ and $\\Delta S_{r,298K}^{o}$. From a list of oxygen carriers possessing favourable thermodynamic properties, the perovskite SrFeO$_{3-\\delta}$ is selected for further investigation. In a tubular micro-reactor, developed and optimised for minimum noise and response time, oxygen transfer capacities and reaction kinetics of the pure, Mn-doped and Co-doped SrFeO$_{3-\\delta}$ are investigated. The rate constants of the reduction reaction have been successfully extracted, however, this was not possible for the oxidation which proceeded too rapidly. The apparent activation energy, $E_{a,app}$, the pre-exponential factor, $A'$, for SrFeO$_{3-\\delta}$, SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$, SrCo$_{0.4}$Fe$_{0.6}$O$_{3-\\delta}$ are 128.9, 45.3 and 271.3 kJ/mol, and 3.9$\\cdot$10$^{5}$, 6.29 and 35.5$\\cdot$10$^{12}$ mol/s/Pa/m$^3$, respectively. SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$ showed both the highest oxygen transfer capacity and rate of reduction and SrCo$_{0.4}$Fe$_{0.6}$O$_{3-\\delta}$ the lowest; around 325 and 117 $\\mu$mol of O$_2$ per gram of oxygen carrier material at 898 K, respectively. When subjecting SrFeO$_{3-\\delta}$ and SrMn$_{0.1}$Fe$_{0.9}$O$_{3-\\delta}$ to 1000 redox cycles, both showed an increase in the maximum observed rate of reduction and the oxygen transfer capacity."],"dc:format.checksum.md5":["69de4e5ffd40805a205c0199a2dd392c","87eda9de84448d1f82354d60eee3eb5f"],"dc:identifier.doi":["10.17863/CAM.47887"],"dc:identifier.uri":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/2ee74558-a6f2-434a-a66c-74098fbc8bc5/download"],"dc:language":["en"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/300813"],"dc:rights":["https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/e9db0b31-df02-46bd-8f88-0102d8f63d34/download","https://creativecommons.org/licenses/by-nc/4.0/","Fig. 1-2, Concept of chemical looping air separation, copyright holder is Elsevier, copyright license number 4726390207289 Fig. 4-3, Phase diagram of Sr-Fe-O under 1 bar of nitrogen, copyright holder is Elsevier, copyright license number 4726391446039"],"dc:subject":["Chemical looping","Air separation","Oxygen Production","Carbon Capture","CCS","Clean Coal","Perovskites","Oxygen Carrier"],"dc:title":["Evaluating new Oxygen Transfer Materials for Air Separation, Oxy-Fuel Combustion and other Processes"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-22T22:24:20Z"}