Matching Items (2)
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- All Subjects: Carbon Capture
- All Subjects: MOF
- Status: Published
Description
The large-scale anthropogenic emission of carbon dioxide into the atmosphere leads to many unintended consequences, from rising sea levels to ocean acidification. While a clean energy infrastructure is growing, mid-term strategies that are compatible with the current infrastructure should be developed. Carbon capture and storage in fossil-fuel power plants is one way to avoid our current gigaton-scale emission of carbon dioxide into the atmosphere. However, for this to be possible, separation techniques are necessary to remove the nitrogen from air before combustion or from the flue gas after combustion. Metal-organic frameworks (MOFs) are a relatively new class of porous material that show great promise for adsorptive separation processes. Here, potential mechanisms of O2/N2 separation and CO2/N2 separation are explored.
First, a logical categorization of potential adsorptive separation mechanisms in MOFs is outlined by comparing existing data with previously studied materials. Size-selective adsorptive separation is investigated for both gas systems using molecular simulations. A correlation between size-selective equilibrium adsorptive separation capabilities and pore diameter is established in materials with complex pore distributions. A method of generating mobile extra-framework cations which drastically increase adsorptive selectivity toward nitrogen over oxygen via electrostatic interactions is explored through experiments and simulations. Finally, deposition of redox-active ferrocene molecules into systematically generated defects is shown to be an effective method of increasing selectivity towards oxygen.
First, a logical categorization of potential adsorptive separation mechanisms in MOFs is outlined by comparing existing data with previously studied materials. Size-selective adsorptive separation is investigated for both gas systems using molecular simulations. A correlation between size-selective equilibrium adsorptive separation capabilities and pore diameter is established in materials with complex pore distributions. A method of generating mobile extra-framework cations which drastically increase adsorptive selectivity toward nitrogen over oxygen via electrostatic interactions is explored through experiments and simulations. Finally, deposition of redox-active ferrocene molecules into systematically generated defects is shown to be an effective method of increasing selectivity towards oxygen.
ContributorsMcIntyre, Sean (Author) / Mu, Bin (Thesis advisor) / Green, Matthew (Committee member) / Lind, Marylaura (Committee member) / Arizona State University (Publisher)
Created2019
Description
The United States and most of the world is pushing to significantly reduce carbon emissions, with many countries intent on fostering carbon negative energy processes to offset ozone depletion and climate changes. 30% of the U.S. greenhouse gas emissions are generated from the combustion of fossil fuels to generate electricity1. Current commercial IGCC carbon capture processes employ a capital and operating cost intensive water-gas shift reaction facilitated by a high temperature reactor followed by a low temperature reactor and an amine absorber to separate the hydrogen and carbon dioxide streams to capture the carbon. Dr. Jerry Y.S. and his laboratory at Arizona State have developed a hydrogen permselective MFI type ZSM-5 zeolite membrane reactor that effectively facilities the water gas shift reaction with high conversion and separates the CO2 and H2 streams during reaction to generate ultrapure retentate and permeate streams. The membrane, formed by secondary free growth, is synthesized on an ultrapure a-alumina membrane support currently purchased from an outside vendor. The purpose of this study was to design an α-alumina support processing plant with capability to supply one full-scale commercial reactor annually with membranes. The design yielded a DCFRoR of 71% for a 20-year project life. A zeolite membrane processing material balance was conducted using alumina support as the raw material. The study showed very low material costs and consumption rates for all materials except a gas used to refine the membrane after processing. The results of both studies were favorable enough to suggest further study.
ContributorsNorman, Taylor Cristine (Author) / Lin, Jerry Y.S. (Thesis director) / Meng, Lie (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-05