Author: Kelly SedorPublisher:
ISBN:
Category :
Languages : en
Pages : 116
Book Description
Novel Oxygen Carrier Materials for Chemical Looping Combustion
Author: Kelly SedorOxygen-carrier Materials for Chemical-looping Combustion
Author: Paul ChoNickel-Alumina Oxygen Carrier Materials for Chemical-looping Combustion
Author: Kelly E. SedorCalcium and Chemical Looping Technology for Power Generation and Carbon Dioxide (CO2) Capture
Author: Paul FennellPublisher: Elsevier
ISBN: 0857097601
Category : Technology & Engineering
Languages : en
Pages : 467
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
Novel Co-precipitated Oxygen Carriers for Chemical Looping Combustion of Gaseous Fuel
Author: Ngozi Chinwe EkpeDevelopment and Characterisation of Oxygen-carrier Materials for Chemical-looping Combustion
Author: Paul ChoPublisher:
ISBN: 9789172916050
Category :
Languages : en
Pages : 61
Book Description
A Novel Mixed Metallic Oxygen Carrier for Chemical Looping Combustion
Author: Mohammad Rezwanul QuddusPublisher:
ISBN:
Category :
Languages : en
Pages : 326
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.
Development of Iron-based Oxygen Carriers in Recyclability, Physical Strength and Toxicity-tolerance for Coal-direct Chemical Looping Combustion Systems
Author: Cheng Lung ChungPublisher:
ISBN:
Category : Chemical engineering
Languages : en
Pages :
Book Description
This dissertation presents investigations of chemical looping technology as a transformative process for combustion of fossil fuels for power generation with CO2 capture. Specifically, the dissertation seeks to synthesize and characterize a low-cost iron-based oxygen carrier that can be employed in a commercial chemical looping combustion system with realistic material lifetime and adequate resistance to toxicity from pollutants from fossil fuels such as coal. Two secondary metal oxides (Al2O3 and TiO2) as support materials for Fe2O3 and their respective reaction-induced morphological changes are presented. A novel iron-based oxygen carrier was consequently identified to be sustainable over 3000 redox cycles in high temperatures (1000 °C) at the lab scale without chemical and physical degradation. Oxygen carrier of the same design also exhibited high resistance toward attrition from circulation and fluidization in two pilot-scale demonstration units under representative conditions. Tolerance of the active ingredients of the iron-based oxygen carriers against common toxic elements in the fossil fuel feedstock, such as alkaline and sulfur compounds from conversion of coal, through multiple fixed bed experiments under conditions representative of the counter-current moving bed reducer and thermogravimetric experiments up to 9000 ppm of H2S. The likelihood of agglomeration and interaction of alkaline metals (Na, K) with the iron-based oxygen carriers were found to be extremely low under normal operating conditions. Instead, proper distribution of coal was more crucial to avoid agglomeration caused by melting of SiO2. Sulfur deposition on iron-based oxygen carriers, although observed, was reversible through regeneration with air and did not result in degradation in the recyclability of the oxygen carriers. A potential pathway for sulfur emission via the combustor spent air was also identified. The sulfur emission and distribution of the Coal-Direct Chemical Looping (CDCL) 25 kWth sub-pilot unit which utilized the iron-based oxygen carriers was determined with a custom heat-traced gas sampling system. More than 69% of the total amount of atomic sulfur from high sulfur coal was converted to SO2 and H2S in the reducer flue gas stream while less than 5% was released as SO2 in the combustor spent air. The missing atomic sulfur in the balance was attributed to sulfur retained in coal ash as inorganic sulfur compounds. A flue gas clean-up system targeting both H2S and SO2 is therefore recommended to meet the quality of CO2-rich stream for transportation and sequestration in a commercial CDCL system. The projected sulfur emission in the combustor spent air was under the US EPA sulfur emission regulation safe to be released to the atmosphere without a costly acid removal system. The findings demonstrate the robustness of the CDCL system, together with the iron-based oxygen carriers, to handle high sulfur coal without severe performance and economic penalties.
Chemical Looping Systems for Fossil Energy Conversions
Author: Liang-Shih FanPublisher: John Wiley & Sons
ISBN: 1118063139
Category : Technology & Engineering
Languages : en
Pages : 353
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.
Handbook of Chemical Looping Technology
Author: Ronald W. BreaultPublisher: John Wiley & Sons
ISBN: 3527342028
Category : Business & Economics
Languages : en
Pages : 488
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.