Reduction kinetics analysis of sol–gel-derived CuO/CuAl2O4 oxygen carrier for chemical looping with oxygen uncoupling

Abstract

Chemical looping with oxygen uncoupling (CLOU) is a promising technology due to its potential to reduce energy efficiency penalty and cost associated with CO 2 capture. In this work, a CuO/CuAl 2 O 4 oxygen carrier (OC) prepared by sol-gel was investigated in its oxygen release kinetics (4CuO ? 2Cu 2 O ? O 2 ). 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 9 10 12 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.

Performance and Kinetic Evaluation of Synthesized CuO/SBA‐15 Oxygen Carrier for Chemical Looping with Oxygen Uncoupling

“…To overcome these limitations and to improve the performances of CuO, various support materials such as Al 2 O 3 , SiO 2 , ZrO 2 , TiO 2 , bentonite, sepiolite, etc., have been explored. A number of OC preparation methods, such as mechanical mixing plus pressurized pelletizing, impregnation, spray drying, and freeze granulation, etc., have been proposed to synthesize these OCs to enhance their performance . Table provides a brief review of research activities on CuO‐based supported OCs for the CLOU process.…”

Molecular Dynamics Simulation of the Microscopic Sintering Process of CuO Nanograins Inside an Oxygen Carrier Particle

“…To date, a lot of materials including TiO 2 , ZrO 2 , SiO 2 , Al 2 O 3 , MgAl 2 O 4 , and CuAl 2 O 4 ,, have been used as the support for CuO due to their thermally stability and high melting point. Various method (e.g., impregnation, sol–gel, mechanical mixing, spray drying) are adopted for the preparation of supported-CuO OC particles, and the preparation processes are almost involved in drying, granulation, calcination, grinding, and sieving. − How to choose appropriate support materials to enhance the sintering resistance becomes a challenge for the preparation of Cu-based OC.…”

Developing Oxygen Carriers for Chemical Looping Biomass Processing: Challenges and Opportunities

“…[134] Cu-Based Oxygen Carriers: Cu-based OCs have received much research attention owing to their high lattice oxygen activity and high oxygen transport capacity. [39] Meanwhile, the main disadvantages of Cu-based OCs include their low melting points and poor mechanical strength, [135], that is, CuO must be supported on refractory-type materials, for example, Al 2 O 3 , [136] MgAl 2 O 4 , [137] CuAl 2 O 4 , [138,139] ZrO 2 , [140,141] TiO 2 -Al 2 O 3 , [142,143] SiO 2 , [144,145] diatomite, [146] bentonite, [147][148][149] sepiolite, [150] and olivine, [97] in order to render resistance against sintering, agglomeration, and attrition. CuO's ability to release gaseous oxygen at temperatures above 800 °C makes it suitable for chemical looping oxygen uncoupling (CLOU).…”