Reduction kinetics analysis of sol–gel-derived CuO/CuAl2O4 oxygen carrier for chemical looping with oxygen uncoupling
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Chemical looping with oxygen uncoupling (CLOU) is a promising technology due to its potential to reduce energy efficiency penalty and cost associated with CO2 capture. In this work, a CuO/CuAl2O4 oxygen carrier (OC) prepared by sol–gel was investigated in its oxygen release kinetics (4CuO → 2Cu2O + O2). Based on several well-organized temperature-programmed reduction experiments which were conducted in a thermogravimetric analyzer, the activation energy E (343.7 kJ mol−1) and pre-exponential factor A (3.78 × 1012 s−1) were determined and the Avrami–Erofeev random nucleation and subsequence growth model fitted well with the reduction experimental data. The enhancement of OC reduction rate in real fluidized bed CLOU reactor using different types of solid fuels (petroleum coke, anthracite, bituminous, and lignite) was identified in terms of the chemical kinetics and thermodynamics for the first time. It was found that the CuO reduction rate is more sensitive to the local temperature change than the oxygen concentration driving force. The results could contribute to the design, operation, and performance prediction of real CLOU reactors.
KeywordsReduction kinetics Solid fuels CLOU Oxygen concentration driving force Kinetics barrier
This research was funded by “National Natural Science Foundation of China (51390494) and 51561125001.” Meanwhile, the staffs from the Analytical and Testing Center and Huazhong University of Science and Technology are also appreciated for the related experimental analysis.
- 6.Abad A, Adánez-Rubio I, Gayan P, Garcia-Labiano F, de Diego LF, Adánez J. Demonstration of chemical-looping with oxygen uncoupling (CLOU) process in a 1.5 kW(th) continuously operating unit using a Cu-based oxygen-carrier. Int J Greenh Gas Control. 2012;6:189–200. doi: 10.1016/j.ijggc.2011.10.016.CrossRefGoogle Scholar
- 30.Brown ME, Dollimore D, Galwey AK. Reactions in the solid state. New York: Elsevier; 1980.Google Scholar
- 32.Arjmand M, Keller M, Leion H, Mattisson T, Lyngfelt A. Oxygen release and oxidation rates of MgAl2O4-supported CuO oxygen carrier for chemical-looping combustion with oxygen uncoupling (CLOU). Energy Fuels. 2012;26(11):6528–39.Google Scholar
- 33.Kubaschewski O, Evans EL, Alcock C. Metallurgical thermochemistry. Oxford: Pergamon press; 1979.Google Scholar