Identifying iron-based oxygen carrier reduction during biomass chemical looping gasification on a thermogravimetric fixed-bed reactor

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.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.872.196 ◽

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%.

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Characterization and Performance in a Multicycle Test in a Fixed-Bed Reactor of Silica-Supported Copper Oxide as Oxygen Carrier for Chemical-Looping Combustion of Methane

Energy & Fuels ◽

10.1021/ef050212n ◽

2006 ◽

Vol 20 (1) ◽

pp. 148-154 ◽

Cited By ~ 53

Author(s):

B. M. Corbella ◽

L. de Diego ◽

F. García-Labiano ◽

J. Adánez ◽

J. M. Palacios

Keyword(s):

Copper Oxide ◽

Oxygen Carrier ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Chemical Looping Combustion ◽

Chemical Looping ◽

And Performance

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Hydrogen production from chemical looping steam reforming of glycerol by Ni-based oxygen carrier in a fixed-bed reactor

Chemical Engineering Journal ◽

10.1016/j.cej.2015.05.120 ◽

2015 ◽

Vol 280 ◽

pp. 459-467 ◽

Cited By ~ 65

Author(s):

Bo Jiang ◽

Binlin Dou ◽

Yongchen Song ◽

Chuan Zhang ◽

Baoguo Du ◽

...

Keyword(s):

Hydrogen Production ◽

Steam Reforming ◽

Oxygen Carrier ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Chemical Looping

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Evaluation of Cu-based oxygen carrier for chemical looping air separation in a fixed-bed reactor

Chemical Engineering Journal ◽

10.1016/j.cej.2015.11.009 ◽

2016 ◽

Vol 287 ◽

pp. 292-301 ◽

Cited By ~ 31

Author(s):

Kun Wang ◽

Qingbo Yu ◽

Qin Qin ◽

Zongliang Zuo ◽

Tianwei Wu

Keyword(s):

Oxygen Carrier ◽

Fixed Bed ◽

Air Separation ◽

Fixed Bed Reactor ◽

Chemical Looping ◽

Chemical Looping Air Separation

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

Energies ◽

10.3390/en12081453 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1453 ◽

Cited By ~ 2

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.

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