- Title
- Reactivity of Al₂O₃- or SiO₂-supported Cu-, Mn-, and Co-based oxygen carriers for chemical looping air separation
- Creator
- Song, Hui; Shah, Kalpit; Doroodchi, Elham; Wall, Terry; Moghtaderi, Behdad
- Relation
- Energy & Fuels Vol. 28, Issue 2, p. 1284-1294
- Publisher Link
- http://dx.doi.org/10.1021/ef402268t
- Publisher
- American Chemical Society
- Resource Type
- journal article
- Date
- 2014
- Description
- The chemical looping air separation (CLAS) is a novel method for producing high-purity oxygen, which can be effectively integrated to oxy-fuel power plants. CuO/Cu₂O, Mn₂O₃/Mn₃O₄, and Co₃O₄/CoO have been found to be the most thermodynamically suitable oxidation pairs for the CLAS process. In the current study, the reactivity and stability of these metal oxides were analyzed further. A total of six different oxygen carrier samples were prepared by the dry impregnation method on SiO₂ and Al₂O₃ supports. Their redox behavior has been investigated in a thermogravimetric analyzer (TGA) at four different temperatures, i.e., 800, 850, 900, and 950 °C, where the temperature-programmed oxygen release and oxidation were applied for 5 continuous cycles using nitrogen and air, respectively. The results indicate that, although relatively all oxygen carriers exhibited good reactivity, CuO/Cu₂O with SiO₂ and Co₃O₄/CoO with Al₂O₃ were found to be most stable. Furthermore, oxygen transport capacity (OTC) (%) and rate of oxygen transport (ROT) (% min⁻¹) were calculated. It was found that Cu oxide with SiO₂ has the highest OTC of 4.77% as well as the highest ROT of 5.1 and 10.9% min⁻¹ for oxygen release and oxidation, respectively, at 950 °C. The CuO/SiO₂ oxygen carrier also exhibited better stability for the 41 continuous cycle test, with only 10.3% loss in OTC compared to 22.3% for Co₃O₄/Al₂O₃. The grain size growth was found to be the key cause in the loss of OTC. The oxygen concentration in the outlet stream for the CuO/SiO₂ oxygen carrier was measured in packed-bed experiments at different temperatures. It was observed that the oxygen concentration at the outlet of the reactor was consistent with the equilibrium values at studied temperatures.
- Subject
- chemical looping air separation (CLAS); high-purity oxygen; oxy-fuel power plants
- Identifier
- http://hdl.handle.net/1959.13/1304198
- Identifier
- uon:20823
- Identifier
- ISSN:0887-0624
- Language
- eng
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