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

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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Syngas Generation from Methane Using a Chemical-Looping Concept: A Review of Oxygen Carriers

Journal of Chemistry ◽

10.1155/2013/294817 ◽

2013 ◽

Vol 2013 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Kongzhai Li ◽

Hua Wang ◽

Yonggang Wei

Keyword(s):

Oxygen Carrier ◽

Cost Savings ◽

Oxygen Storage ◽

Pure Oxygen ◽

Chemical Looping ◽

Oxygen Carriers ◽

Gaseous Oxygen ◽

Solid Oxides ◽

Oxidation Of Methane ◽

Gaseous Oxidant

Conversion of methane to syngas using a chemical-looping concept is a novel method for syngas generation. This process is based on the transfer of gaseous oxygen source to fuel (e.g., methane) by means of a cycling process using solid oxides as oxygen carriers to avoid direct contact between fuel and gaseous oxygen. Syngas is produced through the gas-solid reaction between methane and solid oxides (oxygen carriers), and then the reduced oxygen carriers can be regenerated by a gaseous oxidant, such as air or water. The oxygen carrier is recycled between the two steps, and the syngas with a ratio of H2/CO = 2.0 can be obtained successively. Air is used instead of pure oxygen allowing considerable cost savings, and the separation of fuel from the gaseous oxidant avoids the risk of explosion and the dilution of product gas with nitrogen. The design and elaboration of suitable oxygen carriers is a key issue to optimize this method. As one of the most interesting oxygen storage materials, ceria-based and perovskite oxides were paid much attention for this process. This paper briefly introduced the recent research progresses on the oxygen carriers used in the chemical-looping selective oxidation of methane (CLSOM) to syngas.

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Chemically and physically robust, commercially-viable iron-based composite oxygen carriers sustainable over 3000 redox cycles at high temperatures for chemical looping applications

Energy & Environmental Science ◽

10.1039/c7ee02657a ◽

2017 ◽

Vol 10 (11) ◽

pp. 2318-2323 ◽

Cited By ~ 42

Author(s):

Cheng Chung ◽

Lang Qin ◽

Vedant Shah ◽

Liang-Shih Fan

Keyword(s):

Mechanical Stability ◽

Chemical Reactivity ◽

Low Cost ◽

Oxygen Carrier ◽

Chemical Looping ◽

Titanium Oxides ◽

Oxygen Carriers ◽

Redox Cycles ◽

Iron Based

A low-cost oxygen carrier material realized through an Al-based skeleton encapsulating iron–titanium oxides with long-term chemical reactivity and mechanical stability for commercial chemical looping applications.

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Devolatilization of Residual Biomasses for Chemical Looping Gasification in Fluidized Beds Made up of Oxygen-Carriers

Energies ◽

10.3390/en14020311 ◽

2021 ◽

Vol 14 (2) ◽

pp. 311

Author(s):

Andrea Di Giuliano ◽

Stefania Lucantonio ◽

Katia Gallucci

Keyword(s):

Fluidized Beds ◽

Oxygen Carrier ◽

Reaction Model ◽

Chemical Looping ◽

Oxygen Carriers ◽

First Order ◽

Fluidizing Agent ◽

Mitigate Climate Change ◽

Bubbling Beds ◽

Better Than

The chemical looping gasification of residual biomasses—operated in fluidized beds composed of oxygen-carriers—may allow the production of biofuels from syngas. This biomass-to-fuel chain can contribute to mitigate climate change, avoiding the accumulation of greenhouse gases in our atmosphere. The ongoing European research project Horizon2020 CLARA (G.A. 817841) investigates wheat-straw-pellets (WSP) and raw-pine-forest-residue (RPR) pellets as feedstocks for chemical looping gasification. This work presents experimental results from devolatilizations of WSP and RPR, in bubbling beds made of three different oxygen-carriers or sand (inert reference), at 700, 800, 900 °C. Devolatilization is a key step of gasification, influencing syngas quality and quantity. Tests were performed at laboratory-scale, by a quartz reactor (fluidizing agent: N2). For each pellet, collected data allowed the quantification of released gases (H2, CO, CO2, CH4, hydrocarbons) and mass balances, to obtain gas yield (ηav), carbon conversion (χavC), H2/CO ratio (λav) and syngas composition. A simplified single-first order-reaction model was adopted to kinetically analyze experimental data. WSP performed as RPR; this is a good indication, considering that RPR is similar to commercial pellets. Temperature is the dominating parameter: at 900 °C, the highest quality and quantity of syngas was obtained (WSP: ηav = 0.035–0.042 molgas gbiomass−1, χavC = 73–83%, λav = 0.8–1.0); RPR: ηav = 0.036–0.041 molgas gbiomass−1, χavC = 67–71%, λav = 0.9–1.0), and oxygen-carries generally performed better than sand. The kinetic analysis suggested that the oxygen-carrier ilmenite ensured the fastest conversion of C and H atoms into gases, at tested conditions.

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

Processes ◽

10.3390/pr9122156 ◽

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.

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Reduction and oxidation kinetics of NiWO4 as an oxygen carrier for hydrogen storage by a chemical looping process

RSC Advances ◽

10.1039/d1ra05077j ◽

2021 ◽

Vol 11 (47) ◽

pp. 29453-29465

Author(s):

P. E. González-Vargas ◽

J. M. Salinas-Gutiérrez ◽

M. J. Meléndez-Zaragoza ◽

J. C. Pantoja-Espinoza ◽

A. López-Ortiz ◽

...

Keyword(s):

Hydrogen Storage ◽

Oxidation Kinetics ◽

Oxygen Carrier ◽

Reaction Scheme ◽

High Potential ◽

Chemical Looping ◽

Oxygen Carriers ◽

Storage Density ◽

Reduction And Oxidation ◽

Kinetics Of

H2 storage of NiWO4 with a volumetric storage density of 496 g L−1 was studied and evaluated under a chemical looping reaction scheme by TGA. Results confirms the high potential of NiWO4 to current oxygen carriers reported in the literature.

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Feasibility Study of an Iron-Based Composite Added with Al2O3/ZrO2 as an Oxygen Carrier in the Chemical Looping Applications

Crystals ◽

10.3390/cryst11080971 ◽

2021 ◽

Vol 11 (8) ◽

pp. 971

Author(s):

Ching-Ti Kao ◽

Cheng-Hsien Shen ◽

Heng-Wen Hsu

Keyword(s):

Relative Density ◽

Feasibility Study ◽

Spinel Phase ◽

Oxygen Carrier ◽

Dense Layer ◽

Chemical Looping ◽

Oxygen Carriers ◽

Redox Cycles ◽

Iron Based ◽

Crush Strength

The chemical looping process is a promising approach for carbon capture. Oxygen carriers play the crucial role of carrying oxygen between oxidation and reduction reactors. In this study, iron-based composites, added with alumina and zirconia, were used as the oxygen carriers. The feasibility study of these composites for chemical looping applications was then evaluated by measuring their properties, including mechanical properties, relative density, microstructures, crystal structure, and their capacity of oxygen. The results suggest that the addition of zirconia led the decrease of the bulk relative density and thus had a negative effect to both crush strength and attrition. Crush strength declined from 57 kgf to 26 kgf when using zirconia, replacing alumina, in an iron-based composite as the inner material. In addition, the phases in oxidizing and reducing reaction were also revealed. The formation of the spinel phase (FeAl2O4) was the major factor that altered the capacity of oxygen. It inhibited Fe2O3’s ability to be completely reduced to Fe and thus decrease the capacity of oxygen. The value was therefore decreased from 9.7% to 6.2% after 50 redox cycles in alumina addition composite. On the other hand, for the zirconia addition, all of the Fe2O3 could transform to Fe, which provided 8.5% of oxygen capacity after 50 redox cycles. A dense layer which was identified as the Fe2O3 in the bulk surface was observed in the samples reacted with 50 redox cycles. The proposed mechanism of the formation of Fe2O3 layer and its corresponding kinetic analysis was also revealed in this study.

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