Development of CaO-based Sorbents for Post-Combustion Carbon Capture in the Calcium Looping Process

dc.contributor.advisorMahinpey, Nader
dc.contributor.authorHashemi, Seyed Mojtaba
dc.contributor.committeememberHassanzadeh, Hassan
dc.contributor.committeememberBryant, Steven L.
dc.contributor.committeememberShimizu, George Kisa Hayashi
dc.contributor.committeememberZendehboudi, Sohrab
dc.date2022-06
dc.date.accessioned2022-05-20T16:05:25Z
dc.date.available2022-05-20T16:05:25Z
dc.date.issued2022-05
dc.description.abstractPost-combustion carbon capture with solid sorbents is a low-cost and more efficient alternative to traditional amine technologies for CO2 capture. Calcium looping technology is among the most promising technologies for mitigation of CO2 from industrial flue gases. Low price, high theoretical uptake capacity, fast sorption kinetics, and high-temperature operation are some of the advantages of the calcium looping process. Despite the promising attributes of the process, a main barrier for commercialization of the process is the loss of the uptake capacity of sorbents over cycles. Therefore, development of highly stable sorbents is of utmost importance for commercialization of this technology. To this end, this thesis investigates the fabrication of synthetic sorbents for the calcium looping process, considering two main goals: i) high CO2 uptake capacity, and ii) stability in cyclic operation. In this study, the solution combustion synthesis technique was used for fabrication of CaO-based sorbents. The effect of fuel type and fuel ratio were investigated to optimize the physical properties of the produced sorbents and their CO2 capture performance. Among citric acid, β-alanine, and urea tested in this study, citric acid was determined as the optimum fuel for solution combustion synthesis. A stoichiometric ratio of fuel to oxidizers produced the optimum sorbents in case of citric acid, whereas for urea a high ratio of fuel to oxidizer (6 to 1) produced the best sorbents. The CaO sorbents produced using this method exhibited a high initial uptake capacity (0.69 g/g) and conversion, however, the uptake capacity quickly reduced over cycles due to sintering and agglomeration of CaO grains. To improve the cyclic stability of the sorbents, metal stabilizers with high Tammann temperatures were incorporated into the structure of CaO. Seven different metals (Al, Ce, La, Mg, Nd, Y, and Zr) were investigated at an identical molar ratio of stabilizer to sorbent (M:Ca = 1:14) to find the optimum stabilizer producing the best combination of uptake capacity and stability. Results indicated that Mg-stabilized sorbents are most efficient in terms of their stabilizing effect, owing to the high Tammann temperature of MgO (>1250 °C). Additionally, the uptake capacity of Mg-stabilized sorbent was higher than other sorbents due to the lower molar mass of MgO compared to other metal oxides. Mg-stabilized sorbents maintained an uptake capacity of 0.15 g/g after 100 cycles of carbonation and calcination under industrially relevant calcium looping conditions, a nearly 70% improvement over unpromoted CaO sorbents. Sorbents were further extruded and spheronized using a binder to investigate the cyclic operation in a fixed or fluidized bed reactor setting. The uptake capacity of spherical sorbents was slightly reduced compared to powdery sorbents due to diffusion limitations, as well as addition of a binder during the spheronization process.en_US
dc.identifier.citationHashemi, S. M. (2022). Development of CaO-based sorbents for post-combustion carbon capture in the calcium looping process (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.en_US
dc.identifier.doihttp://dx.doi.org/10.11575/PRISM/39797
dc.identifier.urihttp://hdl.handle.net/1880/114686
dc.language.isoengen_US
dc.publisher.facultySchulich School of Engineeringen_US
dc.publisher.institutionUniversity of Calgaryen
dc.rightsUniversity of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.en_US
dc.subjectCCUSen_US
dc.subjectCarbon captureen_US
dc.subjectCCSen_US
dc.subjectCalcium loopingen_US
dc.subjectsorbenten_US
dc.subjectsolid sorbenten_US
dc.subjectadsorptionen_US
dc.subjectfixed bed reactoren_US
dc.subjectfluidized bed reactoren_US
dc.subjectclimate changeen_US
dc.subjectglobal warmingen_US
dc.subjectCO2en_US
dc.subjectcarbon dioxideen_US
dc.subjectsolution combustionen_US
dc.subjectnanosorbenten_US
dc.subjectnanomaterialen_US
dc.subjectnanoen_US
dc.subjectpost-combustion captureen_US
dc.subject.classificationEnergyen_US
dc.subject.classificationEngineeringen_US
dc.subject.classificationEngineering--Chemicalen_US
dc.subject.classificationEngineering--Environmentalen_US
dc.titleDevelopment of CaO-based Sorbents for Post-Combustion Carbon Capture in the Calcium Looping Processen_US
dc.typedoctoral thesisen_US
thesis.degree.disciplineEngineering – Chemical & Petroleumen_US
thesis.degree.grantorUniversity of Calgaryen_US
thesis.degree.nameDoctor of Philosophy (PhD)en_US
ucalgary.item.requestcopytrueen_US
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