Evaluation of CuAl₂O₄ as an Oxygen Carrier in Chemical-Looping Combustion

Citations Over TimeTop 10% of 2012 papers

Abstract

The chemical-looping combustion (CLC) process is a novel solution for efficient combustion with intrinsic separation of carbon dioxide. The process uses a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, reacts with the solid oxygen carrier. In this work, copper(II) aluminate (CuAl2O4) was assessed as a potential oxygen carrier using methane as fuel. The carrier particles were produced by freeze–granulation and calcined at 1050 °C for a duration of 6 h. The chemical-looping characteristics were evaluated in a laboratory-scale fluidized-bed reactor in the temperature range of 900–950 °C during 45 alternating redox cycles. The oxygen carrier exhibited reproducible and stable reactivity behavior in this temperature range. Neither agglomeration nor defluidization was noticed in any of the cycles carried out at 900–925 °C. However, after reactivity tests at 950 °C, soft agglomeration and particle fragmentation were observed. Systematic phase analysis of the Cu–Al–O system during the redox cycle was carried out as a function of duration of reduction and oxygen concentration during the oxidation period. It was found that the CuAl2O4 is reduced to copper(I) aluminate (CuAlO2; delafossite), Cu2O, and elemental Cu. The CuAlO2 phase is characterized by slow kinetics for oxidation into CuO and CuAl2O4. Despite this kinetic limitation, complete conversion of methane with reproducible reactivity of the oxygen carrier is achieved. Thus, CuAl2O4 could be a potential oxygen carrier for chemical-looping combustion.

Related Papers

• → Improved redox performance of Fe2O3/Al2O3 oxygen carrier via element doping in chemical looping combustion(2021)31 cited
• → Development of MgMnO3-δ as an oxygen carrier material for chemical looping combustion(2018)22 cited
• → Study of Dimensional Changes during Redox Cycling of Oxygen Carrier Materials for Chemical Looping Combustion(2014)15 cited
• → The Effect of CBB(CaO·BaO·B<sub>2</sub>O<sub>3</sub>) Addition on the Physical Properties and Oxygen Transfer Reactivity of NiO-based Oxygen Carriers for Chemical Looping Combustion(2016)1 cited
• Reactivity and stability of Cu-decorated Fe_2O_3/Al_2O_3 oxygen carrier for chemical looping combustion(2014)