scholarly journals Comparison of oxygen carriers for chemical-looping combustion

2006 ◽  
Vol 10 (3) ◽  
pp. 93-107 ◽  
Author(s):  
Marcus Johansson ◽  
Tobias Mattisson ◽  
Anders Lyngfelt
Keyword(s):  
Fossil Fuels ◽  
Oxygen Carrier ◽  
High Reactivity ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Reducing Conditions ◽  
Different Temperatures ◽  
Combustion Technology ◽  
Separation Of Co2

Chemical-looping combustion is a combustion technology with inherent separation of the greenhouse gas CO2. This technique involves combustion of fossil fuels by means of an oxygen carrier which transfers oxygen from the air to the fuel. In this manner a decrease in efficiency is avoided for the energy demanding separation of CO2 from the rest of the flue gases. Results from fifty oxygen carriers based on iron-, manganese- and nickel oxides on different inert materials are compared. The particles were prepared using freeze granulation, sintered at different temperatures and sieved to a size 125-180 mm. To simulate the environment the particles would be exposed to in a chemical-looping combustor, reactivity tests under alternating oxidizing and reducing conditions were performed in a laboratory fluidized bed-reactor of quartz. Reduction was performed in 50% CH4/50% H2O while the oxidation was carried out in 5% O2 in nitrogen. In general nickel particles are the most reactive, followed by manganese. Iron particles are harder but have a lower reactivity. An increase in sintering temperatures normally leads to an increase in strength and decrease in reactivity. Several particles investigated display a combination of high reactivity and strength as well as good fluidization behavior, and are feasible for use as oxygen carriers in chemical-looping combustion.

scholarly journals Chemical looping combustion of biomass for renewable & non- CO2 emissions energy- status and review

2018 ◽  
Vol 7 (2.1) ◽  
pp. 6
Author(s):  
Goli Venkata Siva Naga Sai ◽  
Rajat C Pundlik ◽  
P Venkateswara Rao ◽  
Ganesh R Kale
Keyword(s):  
Fossil Fuels ◽  
Fossil Fuel ◽  
Fuel Combustion ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Fossil Fuel Combustion ◽  
Energy Status ◽  
Energy Demands ◽  
Combustion Technology ◽  
Separation Of Co2

World depends on fossil fuel combustion for thermal energy generation. Fossil fuel combustion leads to the generation of CO2 and extinction of non-renewable resources. To meet the future energy demands replacement of existing technologies should take place in the view of large quantities of GHG’s emissions from fossil fuels and their extinction. Chemical looping combustion (CLC) is primarily a combustion technique with an inherent separation of CO2 from the flue gases. Due to its advantage of negativeCO2 emissions, chemical looping combustion got attention of many researchers since last one and half decade. Recent research advancements in the CLC provided a platform for further research and developments in chemical looping combustion of biomass. This paper reviewsthe CLC of biomass to present the overview of chemical looping combustion technology and its status of biomass utilization as a fuel in CLC reactors.

Comparison of Chemical-Looping with Oxygen Uncoupling and Chemical-Looping Combustion Technology Reaction Mechanism

2014 ◽  
Vol 955-959 ◽  
pp. 2261-2266
Author(s):  
Xiao Ning Gao ◽  
Hui Min Xue ◽  
Yuan Li ◽  
Xue Feng Yin
Keyword(s):  
New Technologies ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
High Efficient ◽  
Direct Separation ◽  
Fuel Reactor ◽  
Combustion Technology

In order to reduce the emission of CO2and control the global greenhouse effect, the paper introduces and compares two new technologies named chemical-looping combustion (CLC) and chemical-looping with oxygen uncoupling (CLOU) that are both high-efficient and clean. Through comparative analysis, CLC has been widely studied because of its direct separation of CO2, reduction loss of the heat, improvement of energy efficiency and avoiding of the generation of fuel type NOxin the combustion process. Besides the current research for metal oxygen carrier, there are some scholars find various non-metal oxygen carriers that have the better performance in CLC. But the study on reactors of CLC is still not mature, especially the solid fuel reactor, which is different from CLOU. In a certain sense, CLOU is an improved technology based CLC, besides the bove advantages, it also can react with coal directly. Many scholars use coal as fuel in the fluidized bed by the technology of CLOU, and the results of them are feasible. So from this perspective, CLOU technology has more broad prospects than CLC in the China.

Review of Hydrogen Production from the Steam-Iron Process by Chemical-Looping Combustion

2014 ◽  
Vol 953-954 ◽  
pp. 966-969 ◽  
Author(s):  
Long Fei Wang ◽  
Shu Zhong Wang ◽  
Ming Luo
Keyword(s):  
Hydrogen Production ◽  
Solid Fuel ◽  
Process Development ◽  
Oxygen Carrier ◽  
Energy Conversion Efficiency ◽  
High Reactivity ◽  
Future Research ◽  
Pure Hydrogen ◽  
Chemical Looping ◽  
Oxygen Carriers

Chemical looping hydrogen production (CLH) is a promising method for pure hydrogen production, which not only can improve energy conversion efficiency and reduce environmental pollution, but also can separate carbon dioxide. This paper try to review the present chemical looping hydrogen process development on the screening of oxygen carrier particles of gaseous fuel and solid fuel, the design of proper reactors, and the system simulation. The design of solid fuel CLH system and the development of oxygen carriers with high reactivity and abrasion resistance for solid fuel at high temperature and pressure will be future research focuses.

scholarly journals Na-β-Al2O3 stabilized Fe2O3 oxygen carriers for chemical looping water splitting: correlating structure with redox stability

2021 ◽  
Author(s):  
Nur Sena Yüzbasi ◽  
Andac Armutlulu ◽  
Thomas Huthwelker ◽  
Paula Abdala ◽  
Christoph Müller
Keyword(s):  
Fossil Fuels ◽  
Oxygen Carrier ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Cycle Number ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Edx Analyses ◽  
H2 Yield

Chemical looping is an emerging technology to produce high purity hydrogen from fossil fuels or biomass with the simultaneous capture of the CO2 produced at the distributed scale. This process requires the availability of stable Fe2O3-based oxygen carriers. Fe2O3-Al2O3 based oxygen carriers exhibit a decay in the H2 yield with cycle number due to the formation of FeAl2O4 that cannot be re-oxidized. In this study, the addition of sodium (via a sodium salt) in the synthesis of Fe2O3-Al2O3 oxygen carriers was assessed as a means to counteract the cyclic deactivation of the oxygen carrier. Detailed insight into the oxygen carrier’s structure was gained by combined X-ray powder diffraction (XRD), X-ray absorption spectroscopy (XAS) at the Al, Na and Fe K-edges and scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy (STEM/EDX) analyses. The addition of sodium prevented the formation of FeAl2O4 and stabilized the oxygen carrier via the formation of a layered structure, Na-β-Al2O3 phase. The resulting material, Na-β-Al2O3 stabilized Fe2O3, showed a very high H2 yield of ca. 13.3 mmol/g during 15 cycles.

scholarly journals Chemical Looping Combustion of Methane: A Technology Development View

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Rutuja Bhoje ◽  
Ganesh R. Kale ◽  
Nitin Labhsetwar ◽  
Sonali Borkhade
Keyword(s):  
Technology Development ◽  
Oxygen Carrier ◽  
Clean Energy ◽  
Unit Weight ◽  
Chemical Looping Combustion ◽  
Process Conditions ◽  
Net Energy ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Byproduct Formation

Methane is a reliable and an abundantly available energy source occurring in nature as natural gas, biogas, landfill gas, and so forth. Clean energy generation using methane can be accomplished by using chemical looping combustion. This theoretical study for chemical looping combustion of methane was done to consider some key technology development points to help the process engineer choose the right oxygen carrier and process conditions. Combined maximum product (H2O + CO2) generation, weight of the oxygen carrier, net enthalpy of CLC process, byproduct formation, CO2emission from the air reactor, and net energy obtainable per unit weight (gram) of oxygen carrier in chemical looping combustion can be important parameters for CLC operation. Carbon formed in the fuel reactor was oxidised in the air reactor and that increased the net energy obtainable from the CLC process but resulted in CO2emission from the air reactor. Use of CaSO4as oxygen carrier generated maximum energy (−5.3657 kJ, 800°C) per gram of oxygen carrier used in the CLC process and was found to be the best oxygen carrier for methane CLC. Such a model study can be useful to identify the potential oxygen carriers for different fuel CLC systems.

The Performance Research on Reaction of Fe2O3/Al2O3 Oxygen Carrier and CO in Chemical-Looping Combustion Process

2012 ◽  
Vol 550-553 ◽  
pp. 974-978
Author(s):  
Wen Yan Li ◽  
Xing Lei Liu ◽  
Qiu Luan Chen ◽  
Feng Ming Chu
Keyword(s):  
Oxygen Carrier ◽  
Combustion Process ◽  
Kinetic Mechanism ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Novel Technology ◽  
Mechanism Function ◽  
Tg And Dtg ◽  
Performance Research

Chemical-looping combustion (CLC) is a novel technology, which has inherent property of separating the greenhouse gas CO2, which uses oxygen carriers to transfer oxygen for combustion from air to fuel. The reactivity of Fe2O3/Al2O3 oxygen carrier was assessed by measuring their ability to oxidize CO. The kinetics and mechanism of oxygen carrier have been studied by TG and DTG techniques. The kinetic mechanism function of the reaction between Fe2O3/Al2O3 and CO has been built using the Coats-Redfern equation.

Thermodynamic and Kinetic Analysis of Ca-Based Oxygen Carrier in Chemical-Looping Combustion

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Chang Jing ◽  
Cui Dejie
Keyword(s):  
Kinetic Analysis ◽  
Oxygen Carrier ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Calcium Sulfide ◽  
Oxygen Carriers ◽  
Thermo Gravimetric ◽  
Caso4 Oxygen Carrier ◽  
Carbon Dioxide Co2 ◽  
Gravimetric Apparatus

Chemical-looping combustion (CLC) is a promising technology to capture carbon dioxide (CO2) inherently and conveniently without the additional apparatus. At present, for some metal oxide oxygen carriers, the high costs and the positive hazards to the environment inhibit the developing of CLC systems. The feasibility of using CaSO4 oxygen carrier in the CLC system is studied in this paper. Through the thermodynamic analysis, the carbon deposition and the sulfur evolution are studied in the reaction between CaSO4 and a typical syngas. In addition, providing that hydrogen (H2) is fed as the gaseous fuel in the CLC system, the kinetic analysis is investigated on the reduction of CaSO4 by H2 and the oxidation of calcium sulfide (CaS) by oxygen (O2) through the thermo-gravimetric apparatus (TGA). The kinetic models are built on the reduction and the oxidation of the oxygen carrier. The results calculated from the models agree well with the experimental data. Finally, the possible reaction mechanisms for the reduction and the oxidation are explored.

Advances in Chemical-Looping Combustion for Solid Fuels

2013 ◽  
Vol 316-317 ◽  
pp. 99-104 ◽  
Author(s):  
Ming Luo ◽  
Shu Zhong Wang ◽  
Long Fei Wang
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Carrier ◽  
Combustion Efficiency ◽  
Chemical Looping Combustion ◽  
Solid Fuels ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Technical Problems ◽  
Solid Coal ◽  
Recent Advances

Chemical-looping combustion (CLC) is a new method for the combustion of fuels with inherent separation of carbon dioxide, which can simultaneously improve combustion efficiency and reduce environmental pollution. Since solid coal is considerably more abundant than natural gas, it would be highly advantageous if the CLC process could be adapted for solid fuels. The present review introduces the technical approaches for the solid fuels CLC process, and the existing technical problems in solid fuels CLC are discussed. The demands in oxygen carriers of chemical looping combustion for solid fuels are analyzed, and the recent advances in metal oxides oxygen carriers (Cu-, Ni- and Fe-based) and calcium based oxygen carrier are summarized. The recent advances in reactor design are outlined. The main problems in reactor deign are mentioned and the relative measures are pointed.

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