scholarly journals Kinetic Behavior of Fabricated CuO/ZrO2 Oxygen Carriers for Chemical Looping Oxygen Uncoupling

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2156
Author(s):  
Young Ku ◽  
Chia-Wei Chang ◽  
Shr-Han Shiu ◽  
Hsuan-Chih Wu ◽  
Niels Michiel Moed
Keyword(s):  
Elevated Temperatures ◽  
Cupric Oxide ◽  
Oxygen Carrier ◽  
Fixed Bed ◽  
Reduction Rate ◽  
Fixed Bed Reactor ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Redox Cycles ◽  
Reduction And Oxidation

Chemical looping with oxygen uncoupling (CLOU) is an innovative alternative to conventional combustion. CuO/ZrO2 oxygen carriers were tested in this system for their effectiveness and resilience. Cupric oxide (CuO) was demonstrated to be a reliable oxygen carrier for oxygen-uncoupling with consistent recyclability even after 50 redox cycles in a thermogravimetric analyzer (TGA). The reduction of CuO to generate Cu2O and oxygen was observed to be improved markedly for experiments operated at higher temperatures; however, the oxidation of Cu2O by air to generate CuO was hindered for experiments carried out at elevated temperatures. The reduction rate of fabricated CuO/ZrO2 particles containing 40% CuO was enhanced with increasing temperature and decreased with increasing particle size for experiments operated in a fixed bed reactor. The geometrical contraction and Avrami-Erofe’ev models were demonstrated to be appropriate for describing the reduction and oxidation of CuO/ZrO2, respectively. The activation energies for the reduction and oxidation were determined to be 250.6 kJ/mol and 57.6 kJ/mol, respectively, based on experimental results in the temperature range between 850 and 1000 °C.

scholarly journals Coal Chemical-Looping with Oxygen Uncoupling (CLOU) Using a Cu-Based Oxygen Carrier Derived from Natural Minerals

Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1453 ◽  
Author(s):  
Ping Wang ◽  
Bret Howard ◽  
Nicholas Means ◽  
Dushyant Shekhawat ◽  
David Berry
Keyword(s):  
Solid Fuel ◽  
Low Cost ◽  
Oxygen Carrier ◽  
Fixed Bed ◽  
Xrd Analysis ◽  
Reaction Rates ◽  
Fixed Bed Reactor ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Redox Cycles

Chemical-looping with oxygen uncoupling (CLOU) is considered a promising technology to burn solid fuels with improved CO2 capture and has the potential to improve fuel conversion and reaction rates. Cu-based oxygen carriers (Cu-OC) are often used in solid fuel CLOU. This study focused on investigating Cu-OC derived from a natural mineral for solid fuel CLOU because of their potentially lower cost compared to synthetic OCs. Reactivity and recyclability of a natural ore-derived Cu-OC on coal char (Powder River Basin sub-bituminous coal) were studied at 900 °C in Ar and air using TGA-QMS and fixed-bed reactor-QMS for five cycles. Cu-OC was prepared by simply heating chalcopyrite in air. Chalcopyrite is one of the principle copper sulfide ores and one of the primary ores for copper. The prepared Cu-OC had primarily CuO and CuFe2O4 (CuOFe2O3) as active compounds based on XRD analysis and an oxygen capacity 3.3% from oxygen uncoupling. The carbon conversion efficiency Xc was 0.94 for reduction at a ratio of Cu-OC to char ϕ = 75 and the product gas was primarily CO2 with trace O2. The reactivities and the rates were similar for five redox cycles. These results indicate that the natural ore-derived material with low cost has potential as a competitive oxygen carrier in solid fuel CLOU based on its reactivity in this study.

Effects of ZnO Addition on Fe2O3/Al2O3 Oxygen Carriers on CH4 Reduction for Chemical Looping Combustion

2016 ◽  
Vol 872 ◽  
pp. 196-200
Author(s):  
Sujinda Thongsermsuk ◽  
Benjapon Chalermsinsuwan ◽  
Prapan Kuchonthara ◽  
Pornpote Piumsomboon
Keyword(s):  
Oxygen Carrier ◽  
Synergetic Effect ◽  
Fixed Bed ◽  
Reduction Process ◽  
Fixed Bed Reactor ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Fuel Gas ◽  
Physical Mixing

Fe2O3/Al2O3/ZnO oxygen carriers with small content ZnO (5 wt% to 10 wt%) were prepared by physical mixing method and were evaluated its capability as an oxygen carrier in a chemical looping combustion. The combustion was conducted by using CH4 as a fuel gas. The reduction process of Fe2O3/Al2O3/ZnO oxygen carrier was carried out in a fixed bed reactor. The solid reduction products were characterized by X-ray diffraction (XRD) and Scanning Electron Microscope with EDS Attachment (SEM-EDS). The results show that the reactivity of Fe2O3/Al2O3/ZnO oxygen carriers is greater than that of Fe2O3/Al2O3 which is implied the synergetic effect between ZnO and Fe2O3. XRD results show that the iron oxide in the oxygen carriers is reduced to metallic iron. SEM-EDS also shows that the iron agglomeration is prevented. Consequently, the suitable content of ZnO in oxygen carriers is ranged from 5 wt% to 10 wt%.

Performance in a Fixed-Bed Reactor of Titania-Supported Nickel Oxide as Oxygen Carriers for the Chemical-Looping Combustion of Methane in Multicycle Tests

2006 ◽  
Vol 45 (1) ◽  
pp. 157-165 ◽  
Author(s):  
Beatriz M. Corbella ◽  
Luis F. de Diego ◽  
Francisco García-Labiano ◽  
Juan Adánez ◽  
José M. Palacios
Keyword(s):  
Nickel Oxide ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Oxygen Carriers

Chemical-looping combustion of methane with CaSO4 oxygen carrier in a fixed bed reactor

2008 ◽  
Vol 49 (11) ◽  
pp. 3178-3187 ◽  
Author(s):  
Qilei Song ◽  
Rui Xiao ◽  
Zhongyi Deng ◽  
Huiyan Zhang ◽  
Laihong Shen ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Caso4 Oxygen Carrier

Hydrogen production from chemical looping steam reforming of glycerol by Ni based Al-MCM-41 oxygen carriers in a fixed-bed reactor

Fuel ◽  
2016 ◽  
Vol 183 ◽  
pp. 170-176 ◽  
Author(s):  
Bo Jiang ◽  
Binlin Dou ◽  
Kaiqiang Wang ◽  
Yongchen Song ◽  
Haisheng Chen ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Mcm 41

scholarly journals Computational Fluid Dynamics Modeling of the Fuel Reactor in NETL's 50 kWth Chemical Looping Facility

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Ronald W. Breault ◽  
Justin Weber ◽  
Doug Straub ◽  
Sam Bayham
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Oxygen Carrier ◽  
Fixed Bed ◽  
Nucleation And Growth ◽  
Chemical Looping ◽  
Gravimetric Analysis ◽  
Oxygen Carriers ◽  
Dynamics Modeling ◽  
Fuel Reactor

The National Energy Technology Laboratory (NETL) has explored chemical looping in its 50 kWth facility using a number of oxygen carriers. In this work, the results for methane conversion in the fuel reactor with a hematite iron ore as the oxygen carrier are analyzed. The experimental results are compared to predictions using CPFD's barracuda computational fluid dynamics (CFD) code with kinetics derived from the analysis of fixed bed data. It has been found through analytical techniques from thermal gravimetric analysis data as well as the same fixed bed data that the kinetics for the methane–hematite reaction follows a nucleation and growth or Johnson–Mehl–Avrami (JMA) reaction mechanism. barracuda does not accept nucleation and growth kinetics; however, there is enough sufficient variability of the solids dependence within the software such that the nucleation and growth behavior can be mimicked. This paper presents the method to develop the pseudo-JMA kinetics for barracuda extracted from the fixed bed data and then applies these values to the fuel reactor data to compare the computational results to experimental data obtained from 50 kWth unit for validation. Finally, a fuel reactor design for near complete conversion is proposed.

scholarly journals LaFe1-xNix as a Robust Catalytic Oxygen Carrier for Chemical Looping Conversion of Toluene

2021 ◽  
Vol 12 (1) ◽  
pp. 391
Author(s):  
Haiming Gu ◽  
Juan Yang ◽  
Guohui Song ◽  
Xiaobo Cui ◽  
Miaomiao Niu ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Fixed Bed ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Carbon Gasification ◽  
Syngas Production ◽  
Toluene Conversion ◽  
Substituted Ferrite ◽  
Tar Model Compound ◽  
H2 Yield

Chemical looping biomass gasification is a novel technology converting biomass into syngas, and the selection of oxygen carrier is key for efficient tar conversion. The performance of LaFe1-xNix as a robust catalytic oxygen carrier was investigated in the chemical looping conversion of toluene (tar model compound) into syngas in a fixed bed. LaM (M = Fe, Ni, Mn, Co, and Cu) was initially compared to evaluate the effect of transition metal on toluene conversion. LaFe (partial oxidation) and LaNi (catalytic pyrolysis) exhibited better performance in promoting syngas production than other oxygen carriers. Therefore, Ni-substituted ferrite LaFe1-xNix (x = 0, 0.2, 0.4, 0.6, 0.8 and 1) was further developed. The effects of Ni-substitution, steam/carbon ratio (S/C), and temperature on toluene conversion into C1 and H2 were evaluated. Results showed that the synergistic effect of Fe and Ni promoted toluene conversion, improving H2 yield yet with serious carbon deposition. Steam addition promoted toluene steam reforming and carbon gasification. With S/C increasing from 0.8 to 2.0, the C1 and H2 yield increased from 73.9% to 97.5% and from 197.7% to 269.6%, respectively. The elevated temperature favored toluene conversion and C1 yield. LaFe0.6Ni0.4 exhibited strong reactivity stability during toluene conversion at S/C = 1.6 and 900 °C.

The Sustainable Capability Research on Copper- and Iron-Based Oxygen Carrier

2010 ◽  
Vol 146-147 ◽  
pp. 1398-1401
Author(s):  
Lei Chen ◽  
Jing Jin ◽  
Hui Wei Duan
Keyword(s):  
Oxygen Carrier ◽  
Pure Oxygen ◽  
Chemical Looping ◽  
Oxygen Carriers ◽  
Reaction Ratio ◽  
Iron Based ◽  
Reduction And Oxidation ◽  
The One ◽  
The Comparative Study ◽  
Better Than

Chemical-looping combustion (CLC) is a new kind of efficient method to separate CO2. At present, most of CLC research focuses on the development of oxygen carriers. The sustainable capability is the one of important standards to evaluate performance of oxygen carrier. The iron- based and copper- based oxygen carrier were chosen in this paper. The comparative study between the analytically pure oxygen carriers and the prepared oxygen carriers with Al2O3 were made according to the reactivity of reduction and oxidation. The data was obtained by the TGA, SEM and XRD. The results show that the prepared carriers with Al2O3 are greatly improved both in reaction ratio and sustainable capability, and Fe- based oxygen carrier is better than the Cu- based oxygen carrier in the sustainable capability.

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