Processing and Evaluation of Next Generation Oxygen Carrier Materials for Chemical Looping Combustion

Processing and Evaluation of Next Generation Oxygen Carrier Materials for Chemical Looping Combustion PDF Author: Mina Hamedi Rad
Publisher:
ISBN:
Category : Oxides
Languages : en
Pages : 104

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Book Description
This study follows two methods to achieve a modified CaMnO3-d structure with higher oxygen capacity and stability. The first method is replacement of manganese with iron as a cheaper alternative and the second method is size effect investigations of A-site dopants on CaMn0.9Fe0.1O3-d and its oxygen capacity and stability. Solid state reaction followed by mechanical extrusion is used as the preparation method. All synthesized perovskites are characterized by TGA and XRD analyses. The samples of highest oxygen capacity and stability are further characterized by SEM and BET analyses. Oxygen uncoupling behavior and reactivity of these samples are also examined using a fluidized bed reactor performing Chemical Looping Combustion. The temperature effect is also investigated during chemical looping process at temperatures of 800, 850, 900 and 950 °C. In the first method, since calcium could not be incorporated in the structure, strontium is used as the A-site cation. SrFeO3-d has shown to be more stable than CaMnO3-d. However, because of low oxygen capacity, it is doped on the A-site (La and Ba) and B-site (Al, Ti, Mn, Co) by 10 mol% (Sr0.9La0.1FeO3-d, Sr0.9Ba0.1FeO3-d, SrFe0.9Al0.1O3-d, ii SrFe0.9Ti0.1O3-d, SrFe0.9Mn0.1O3-d, SrFe0.9Co0.1O3-d). Results reveal that manganese doped structure (SrFe0.9Mn0.1O3-d) has the highest oxygen capacity. Adding more manganese to the structure increases the oxygen capacity even further. The best iron-based structure has 30 mol% manganese, doped on the B-site, having 28% mass change in an inert atmosphere (SrFe0.7Mn0.3O3-d, SFM73) and high stability. Results of conducted experiments in second method demonstrated that Strontium doped perovskite (Ca0.9Sr0.1Mn0.9Fe0.1O3-d, CS91MF91) is the best synthesized oxygen carrier among all synthesized manganese and iron-based perovskites. This material shows excellent oxygen uptake and release (1.78 wt. %) and high stability. The reactivity and oxygen uncoupling behavior experiments of SFM73 and CS91MF91 show no uncoupling behavior in the synthesized perovskites, nearly complete methane conversion for SFM73 and complete methane conversion for CS91MF91. The synthesized perovskites also possess high stability and no agglomeration tendency.

Processing and Evaluation of Next Generation Oxygen Carrier Materials for Chemical Looping Combustion

Processing and Evaluation of Next Generation Oxygen Carrier Materials for Chemical Looping Combustion PDF Author: Mina Hamedi Rad
Publisher:
ISBN:
Category : Oxides
Languages : en
Pages : 104

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Book Description
This study follows two methods to achieve a modified CaMnO3-d structure with higher oxygen capacity and stability. The first method is replacement of manganese with iron as a cheaper alternative and the second method is size effect investigations of A-site dopants on CaMn0.9Fe0.1O3-d and its oxygen capacity and stability. Solid state reaction followed by mechanical extrusion is used as the preparation method. All synthesized perovskites are characterized by TGA and XRD analyses. The samples of highest oxygen capacity and stability are further characterized by SEM and BET analyses. Oxygen uncoupling behavior and reactivity of these samples are also examined using a fluidized bed reactor performing Chemical Looping Combustion. The temperature effect is also investigated during chemical looping process at temperatures of 800, 850, 900 and 950 °C. In the first method, since calcium could not be incorporated in the structure, strontium is used as the A-site cation. SrFeO3-d has shown to be more stable than CaMnO3-d. However, because of low oxygen capacity, it is doped on the A-site (La and Ba) and B-site (Al, Ti, Mn, Co) by 10 mol% (Sr0.9La0.1FeO3-d, Sr0.9Ba0.1FeO3-d, SrFe0.9Al0.1O3-d, ii SrFe0.9Ti0.1O3-d, SrFe0.9Mn0.1O3-d, SrFe0.9Co0.1O3-d). Results reveal that manganese doped structure (SrFe0.9Mn0.1O3-d) has the highest oxygen capacity. Adding more manganese to the structure increases the oxygen capacity even further. The best iron-based structure has 30 mol% manganese, doped on the B-site, having 28% mass change in an inert atmosphere (SrFe0.7Mn0.3O3-d, SFM73) and high stability. Results of conducted experiments in second method demonstrated that Strontium doped perovskite (Ca0.9Sr0.1Mn0.9Fe0.1O3-d, CS91MF91) is the best synthesized oxygen carrier among all synthesized manganese and iron-based perovskites. This material shows excellent oxygen uptake and release (1.78 wt. %) and high stability. The reactivity and oxygen uncoupling behavior experiments of SFM73 and CS91MF91 show no uncoupling behavior in the synthesized perovskites, nearly complete methane conversion for SFM73 and complete methane conversion for CS91MF91. The synthesized perovskites also possess high stability and no agglomeration tendency.

Handbook of Chemical Looping Technology

Handbook of Chemical Looping Technology PDF Author: Ronald W. Breault
Publisher: John Wiley & Sons
ISBN: 3527342028
Category : Business & Economics
Languages : en
Pages : 488

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Book Description
This comprehensive and up-to-date handbook on this highly topical field, covering everything from new process concepts to commercial applications. Describing novel developments as well as established methods, the authors start with the evaluation of different oxygen carriers and subsequently illuminate various technological concepts for the energy conversion process. They then go on to discuss the potential for commercial applications in gaseous, coal, and fuel combustion processes in industry. The result is an invaluable source for every scientist in the field, from inorganic chemists in academia to chemical engineers in industry.

Fe2O3-based Oxygen Carriers for Gaseous and Solid-fueled Chemical Looping Processes

Fe2O3-based Oxygen Carriers for Gaseous and Solid-fueled Chemical Looping Processes PDF Author: Ankita Majumder
Publisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages : 204

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Book Description
Chemical looping is an efficient, economic and sustainable means for electricity and/or chemicals production with inherent CO2 sequestration ability. Oxygen carriers play a crucial role in the successful operation of a chemical looping system as their physical and chemical properties dictate the fuel conversion efficiency of the system. They are expected to undergo multiple redox cycles while maintaining their reactivity and mechanical strength in order to improve the overall process economics for commercial viability. This research investigates the behavior of oxygen carriers under different reactive conditions and evaluates their feasibility for biomass chemical looping systems. The reduction kinetics of OSU’s iron titanium complex metal oxide (ITCMO) oxygen carrier particles are investigated at elevated pressures with H2 and CH4 for application in OSU’s Shale gas-to-Syngas process. Under CH4, there is almost a 5-fold increase in the reduction rate with an increase in pressure from 1 to 10 atm. Solid characterization revealed increased porosity and surface area at elevated pressures. Faster reaction kinetics at higher pressures can translate into increased processing capacity, reduced reactor sizing, and decreased capital costs. The steam to H4 conversion efficiency of Fe2O3 based oxygen carriers using Al2O3, MgAl2O4 and TiO2 as support materials is investigated in a fixed bed for chemical looping H2 generation. All supported-Fe2O3 based oxygen carriers exhibited >70% steam conversion, close to thermodynamic predictions. Due to its ability to not form complexes with the active material, MgAl2O4 -supported Fe2O3 was selected for further investigation. Thermogravimetric studies with steam oxidation exhibited excellent recyclability and no significant drop in reactivity. MgAl2O4 -supported Fe2O3 also exhibited enhanced steam oxidation kinetics at elevated pressures. Tar derived from biomass pyrolysis is a major concern for biomass thermochemical conversion processes. For biomass fueled chemical looping processes, it is important to evaluate effects of tars on the oxygen carriers. Fixed bed experiments demonstrated that OSU’s ITCMO oxygen carriers have reasonable reactivity for cracking most biomass-derived tar components. To further enhance the tar cracking ability of Fe2O3 -based oxygen carriers, they are combined with traditional tar cracking catalysts. Based on thermogravimetric reactivity and fixed bed tar cracking experiments, NiO is selected as an additive for Fe2O3 -based oxygen carriers for biomass chemical looping systems. The outcomes from this research will help in the development of economic and efficient oxygen carriers for the commercialization of the various chemical looping applications.

Chemical Looping Systems for Fossil Energy Conversions

Chemical Looping Systems for Fossil Energy Conversions PDF Author: Liang-Shih Fan
Publisher: John Wiley & Sons
ISBN: 1118063139
Category : Technology & Engineering
Languages : en
Pages : 353

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Book Description
This book presents the current carbonaceous fuel conversion technologies based on chemical looping concepts in the context of traditional or conventional technologies. The key features of the chemical looping processes, their ability to generate a sequestration-ready CO2 stream, are thoroughly discussed. Chapter 2 is devoted entirely to the performance of particles in chemical looping technology and covers the subjects of solid particle design, synthesis, properties, and reactive characteristics. The looping processes can be applied for combustion and/or gasification of carbon-based material such as coal, natural gas, petroleum coke, and biomass directly or indirectly for steam, syngas, hydrogen, chemicals, electricity, and liquid fuels production. Details of the energy conversion efficiency and the economics of these looping processes for combustion and gasification applications in contrast to those of the conventional processes are given in Chapters 3, 4, and 5.Finally, Chapter 6 presents additional chemical looping applications that are potentially beneficial, including those for H2 storage and onboard H2 production, CO2 capture in combustion flue gas, power generation using fuel cell, steam-methane reforming, tar sand digestion, and chemicals and liquid fuel production. A CD is appended to this book that contains the chemical looping simulation files and the simulation results based on the ASPEN Plus software for such reactors as gasifier, reducer, oxidizer and combustor, and for such processes as conventional gasification processes, Syngas Chemical Looping Process, Calcium Looping Process, and Carbonation-Calcination Reaction (CCR) Process. Note: CD-ROM/DVD and other supplementary materials are not included as part of eBook file.

A Novel Mixed Metallic Oxygen Carrier for Chemical Looping Combustion

A Novel Mixed Metallic Oxygen Carrier for Chemical Looping Combustion PDF Author: Mohammad Rezwanul Quddus
Publisher:
ISBN:
Category :
Languages : en
Pages : 326

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Book Description
In last decades, significant concerns have been raised regarding the global warming effects. To date, about one - third of the total anthropogenic CO2 emission results from power generation using fossil based fuel and CO2 is regarded as the main contributor to global warming. Therefore, technologies for efficient capture of CO2 are becoming of great value. In this respect, Chemical-Looping Combustion (CLC) has received significant attention as a promising technology facilitating concurrent CO2 capture and power generation. This non - conventional technique employs a solid carrier, known as oxygen carrier, to supply oxygen and it facilitates the combustion process in absence of N2 diluted air. Therefore, the combustion products (CO2 and water) are easily separable without any extra downstream processing cost involved in other available alternatives. However, the non- vailability of suitable oxygen carriers still hinders the commercialization of CLC. This study, thus, deals with the development of a new mixed metallic oxygen carrier, Ni-Co/La-?-Al2O3. Several characterization techniques are used to evaluate the reactivity and stability of the prepared oxygen carriers under the industrial-scale conditions of a CLC processes. Apart from the beneficia l effects of La and Co, the reducibility and the structural properties of the prepared oxygen carriers are found to be influenced significantly by the different preparation methods used. N2 adsorption isotherms show that?-Al2O3 retains its structural int egrity under some specific preparation conditions. Reducibility as determined by consecutive temperature programmed techniques resembles the chemical properties of? - and?-Al2O3 for the other preparation techniques. However, no bulk phase change is detected for all the oxygen carriers studied using XRD. The SEM/EDX and H2 chemisorption analyses show the absence of metal agglomeration and suggest that the prepared oxygen carriers are highly stable under CLC operating conditions. The prepared oxygen carriers are also tested for reactivity, stability and fluidizability in the CREC Riser Simulator using multiple reduction/oxidation cycles with CLC fuel. Results obtained show expected reducibility, oxygen carrying capacity and stability. The solid-state kinetics of the reduction processes are developed using nucleation and nuclei growth model (NNGM) and unreacted shrinking core model (USCM). The NNGM model shows better adequacy over USCM in describing the mechanism of reduction process.

Chemical Looping Combustion Reactions and Systems

Chemical Looping Combustion Reactions and Systems PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Chemical Looping Combustion (CLC) is one promising fuel-combustion technology, which can facilitate economic CO2 capture in coal-fired power plants. It employs the oxidation/reduction characteristics of a metal, or oxygen carrier, and its oxide, the oxidizing gas (typically air) and the fuel source may be kept separate. This topical report discusses the results of four complementary efforts: (5.1) the development of process and economic models to optimize important design considerations, such as oxygen carrier circulation rate, temperature, residence time; (5.2) the development of high-performance simulation capabilities for fluidized beds and the collection, parameter identification, and preliminary verification/uncertainty quantification; (5.3) the exploration of operating characteristics in the laboratoryscale bubbling bed reactor, with a focus on the oxygen carrier performance, including reactivity, oxygen carrying capacity, attrition resistance, resistance to deactivation, cost and availability; and (5.4) the identification of kinetic data for copper-based oxygen carriers as well as the development and analysis of supported copper oxygen carrier material. Subtask 5.1 focused on the development of kinetic expressions for the Chemical Looping with Oxygen Uncoupling (CLOU) process and validating them with reported literature data. The kinetic expressions were incorporated into a process model for determination of reactor size and oxygen carrier circulation for the CLOU process using ASPEN PLUS. An ASPEN PLUS process model was also developed using literature data for the CLC process employing an iron-based oxygen carrier, and the results of the process model have been utilized to perform a relative economic comparison. In Subtask 5.2, the investigators studied the trade-off between modeling approaches and available simulations tools. They quantified uncertainty in the high-performance computing (HPC) simulation tools for CLC bed applications. Furthermore, they performed a sensitivity analysis for velocity, height and polydispersity and compared results against literature data for experimental studies of CLC beds with no reaction. Finally, they present an optimization space using simple non-reactive configurations. In Subtask 5.3, through a series of experimental studies, behavior of a variety of oxygen carriers with different loadings and manufacturing techniques was evaluated under both oxidizing and reducing conditions. The influences of temperature, degree of carrier conversion and thermodynamic driving force resulting from the difference between equilibrium and system O2 partial pressures were evaluated through several experimental campaigns, and generalized models accounting for these influences were developed to describe oxidation and oxygen release. Conversion of three solid fuels with widely ranging reactivities was studied in a small fluidized bed system, and all but the least reactive fuel (petcoke) were rapidly converted by oxygen liberated from the CLOU carrier. Attrition propensity of a variety of carriers was also studied, and the carriers produced by freeze granulation or impregnation of preformed substrates displayed the lowest rates of attrition. Subtask 5.4 focused on gathering kinetic data for a copper-based oxygen carrier to assist with modeling of a functioning chemical looping reactor. The kinetics team was also responsible for the development and analysis of supported copper oxygen carrier material.

Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture

Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture PDF Author: Paul Fennell
Publisher: Elsevier
ISBN: 0857097601
Category : Technology & Engineering
Languages : en
Pages : 467

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Book Description
Calcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to chemical looping and combustion. Chapters review the market development, economics, and deployment of these systems, also providing detailed information on the variety of materials and processes that will help to shape the future of CO2 capture ready power plants. - Reviews the fundamental principles, systems, oxygen carriers, and carbon dioxide carriers relevant to calcium and chemical looping - Provides a lucid explanation of advanced concepts and developments in calcium and chemical looping, high pressure systems, and alternative CO2 carriers - Presents information on the market development, economics, and deployment of these systems

Oxygen-carrier Materials for Chemical-looping Combustion

Oxygen-carrier Materials for Chemical-looping Combustion PDF Author: Paul Cho
Publisher:
ISBN:
Category :
Languages : en
Pages : 33

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Book Description


Novel Oxygen Carrier Materials for Chemical Looping Combustion

Novel Oxygen Carrier Materials for Chemical Looping Combustion PDF Author: Kelly Sedor
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

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26th European Symposium on Computer Aided Process Engineering

26th European Symposium on Computer Aided Process Engineering PDF Author:
Publisher: Elsevier
ISBN: 0444634444
Category : Computers
Languages : en
Pages : 2482

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Book Description
26th European Symposium on Computer Aided Process Engineering contains the papers presented at the 26th European Society of Computer-Aided Process Engineering (ESCAPE) Event held at Portorož Slovenia, from June 12th to June 15th, 2016. Themes discussed at the conference include Process-product Synthesis, Design and Integration, Modelling, Numerical analysis, Simulation and Optimization, Process Operations and Control and Education in CAPE/PSE. Presents findings and discussions from the 26th European Society of Computer-Aided Process Engineering (ESCAPE) Event