Defluidization of ilmenite, an oxygen carrier for chemical looping combustion – laboratory experiments with potassium salts

Research output: Chapter in Book/Conference proceedingConference contributionScientificpeer-review

Abstract

Use of biomass in Chemical Looping Combustion (CLC) and subsequent CO2 capture ideally leads to negative CO2 emissions (Bio-CLC).  In Bio-CLC ash-forming matter of biomass, mainly consisting of potassium, calcium, sulfur, phosphorus, and chlorine, may interact with the oxygen carrier, causing agglomeration, and thus inhibit the chemical looping process. The detailed/exact mechanisms behind these effects are not properly understood. Ilmenite, an iron-titanium mineral, can be used as an oxygen carrier in CLC.In this study the interactions between ilmenite and potassium compounds, typical for biofuel ashes, in a labscale furnace were investigated. Mixtures of ilmenite with different potassium compounds were thermally treated in an oxidizing environment at 850 and 950 °C. The interactions between potassium compounds and the carrier material were studied using DTA, XRD, and SEM-EDS. Thermodynamic equilibrium calculations were carried out to verify the reactions.  Finally, results from the laboratory tests were used to explain the behavior of ilmenite in the presence of salts in a lab-scale fluidized bed conversion. The bed agglomeration mechanisms depend on the potassium salt: dihydrogen phosphate or chloride glued the particles, whereas carbonate reacted with the bed particles.
Original languageUndefined/Unknown
Title of host publication30th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, July 2-6, San Diego, California : ECOS 2017
EditorsAsfaw Beyene
PublisherSan Diego State University
Pages1–12
Publication statusPublished - 2017
MoE publication typeA4 Article in a conference publication
EventInternational Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems - 30th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS-2017
Duration: 2 Jul 20176 Jul 2017

Conference

ConferenceInternational Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems
Period02/07/1706/07/17

Keywords

  • Ash interaction
  • Chemical Looping Combustion
  • Ilmenite

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