Chemical Looping With Oxygen Uncoupling Research Articles

Chemical looping with oxygen uncoupling: an advanced biomass combustion technology to avoid CO2 emissions

Bioenergy with carbon dioxide (CO2) capture and storage (BECCS) technologies represent an interesting option to reach negative carbon emissions, which implies the removal of CO2 already emitted to the atmosphere. Chemical looping combustion (CLC) with biomass can be considered as a promising BECCS technology since CLC has low cost and energy penalty. In CLC, the oxygen needed for combustion is supplied by a solid oxygen carrier circulating between the fuel and air reactors. In the fuel reactor, the fuel is oxidized producing a CO2-concentrated stream while the oxygen carrier is reduced. In the air reactor, the oxygen carrier is regenerated with air. Chemical looping with oxygen uncoupling (CLOU) is a CLC technology that allows the combustion of solid fuels as in common combustion with air by means of an oxygen carrier that release gaseous oxygen in the fuel reactor. In the last years, several Cu-based, Mn-based, and mixed oxide oxygen (O2) carriers have been tested showing good CLOU properties. Among them, copper (Cu)-based and Cu-Manganese (Mn) mixed oxides showed high reactivity, O2 release rate, and high O2 equilibrium concentration. The aim of this work is to study the viability of biomass combustion by CLOU process. The combustion of three types of biomass (pine sawdust, olive stone, and almond shell) were studied in a continuous 1.5 kWth CLC unit. Two O2 carriers were tested: a Cu-based oxygen carrier with Magnesium, Aluminum, Oxgen (MgAl2O4) as an inert prepared by spray drying (Cu60MgAl) and a mixed Cu-Mn oxide prepared by spray granulation (Cu34Mn66). These materials are capable of releasing gaseous oxygen when they are reduced in a different range of temperatures. CO2 capture and combustion efficiency were evaluated. Two fuel reactor operation temperatures were used: 775–850 °C for Cu34Mn66 and 900–935 °C for Cu60MgAl. High CO2 capture efficiencies and 100% combustion efficiency were reached with both oxygen carriers and with all the biomasses tested. Therefore, the CLOU technology with the Cu- and Cu-Mn-based oxygen carriers allowed avoiding CO2 emissions maintaining high combustion efficiencies. Results obtained demonstrate that this innovative biomass combustion technology combined with carbon storage lets an efficient BECCS process implementation.

Conversion of Coal in a Fluidized Bed Chemical Looping Combustion Reactor with and without Oxygen Uncoupling

Chemical looping combustion (CLC) is a carbon capture technology that involves circulating metal-based oxygen carrier particles between two reactors, where the metal is alternately oxidized by air and then reduced by fuel as the fuel combusts. In the variant of CLC known as chemical looping with oxygen uncoupling (CLOU), the oxygen carrier releases gaseous O2 in the fuel reactor, allowing for a rapid reaction with solid fuels. This study focuses on improving the understanding of mechanisms responsible for carbon conversion of coal and coal char in a bench-scale fluidized bed reactor using oxygen carriers with and without oxygen uncoupling properties. Effects of coal particle size and temperature on the rate of carbon conversion are evaluated in order to quantify performance and to aid in design and modeling of large-scale fully circulating chemical looping systems. The data confirms that conversion with a copper-based CLOU carrier is faster and results in lower CO and CH4 concentrations than the natural o...

Evaluation of Mn-Fe mixed oxide doped with TiO2 for the combustion with CO2 capture by Chemical Looping assisted by Oxygen Uncoupling

Bimetallic manganese-iron materials have been identified as suitable oxygen carriers for Chemical Looping Combustion (CLC) and Chemical Looping with Oxygen Uncoupling (CLOU) processes. These materials allow the combustion of a fuel with inherent CO2 capture according to two parallel mechanisms: reaction with lattice oxygen and oxygen uncoupling. This work is focused on the evaluation of the reactivity and physicochemical characterization of oxygen carrier particles consisting of a manganese-iron mixed oxide with manganese to iron molar ratio of 66:34 and doped with titanium (7 wt% TiO2) with the objective of determining suitable conditions to be used in CLC and CLOU processes. Particles were prepared by spray drying and the sintering procedure was optimized in order to achieve particles with high reactivity and mechanical strength. In addition, suitable magnetic properties were also sought in order to allow oxygen carrier recover and reuse in a chemical looping unit burning solid fuels. Optimum operating conditions for the fuel combustion and regeneration stages were determined in order to promote the oxygen uncoupling mechanism. Thus, temperature during the fuel combustion must be as high as possible to enhance the oxygen transference; but conditions for oxygen carrier regeneration by air must be carefully selected in order to take advantage of the oxygen uncoupling capability of this material. An oxidizing temperature interval of 1123–1173 K maximized the regeneration, while an air excess higher than 20% would be recommended in order to guarantee oxygen uncoupling capability.

Oxygen Vacancy Creation Energy in Mn-Containing Perovskites: An Effective Indicator for Chemical Looping with Oxygen Uncoupling

Chemical looping with oxygen uncoupling (CLOU) is a novel process for carbon dioxide capture from coal combustion. Designing a metal oxide oxygen carrier with suitable oxygen release and uptake (re...

CO2 Gasification of a Lignite Char in Microfluidized Bed Thermogravimetric Analysis for Chemical Looping Combustion and Chemical Looping with Oxygen Uncoupling

Chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) are novel combustion technologies with low energy penalty CO2 capture. In a CLC/CLOU unit, the gasification of c...

Chemical Looping Combustion Using Two Different Perovskite Based Oxygen Carriers: A Pilot Study.

Two perovskite type oxygen carriers, for the application in chemical looping combustion, called C14 and C28 are investigated. The composition of C14 is CaMn0.9Mg0.1O3−δ and CaMn0.775Mg0.1Ti0.125O3−δ for C28, respectively. Both oxygen carriers allow chemical looping with oxygen uncoupling (CLOU), they release oxygen under conditions with low oxygen partial pressure. The materials are tested in a 120 kWth pilot plant at TU Wien. Operating temperatures from 800 °C to 960 °C are investigated, further the influence of active inventory and air equivalence number is reviewed. In addition to the experiments in the pilot plant, particle analysis is performed. In total, the CLC operation for C14 was 29.5 h and 22.7 h for C28, resulting in 75 different operating points. Both oxygen carrier materials are able to fully convert the natural gas, used as fuel. A temperature dependency is noticeable for both, the best results are achieved at 960 °C, the highest investigated temperature. Both, C14 and C28 are able to release about 10 % of the total available oxygen via oxygen uncoupling. The performance of both oxygen carriers is strongly linked to the air equivalence number and the resulting amount of excess oxygen in the air reactor. Low oxygen partial pressures lead to incomplete fuel conversion.

Deactivation Behavior of a Refractory-Brick Supported CuO Material in Decomposition-Oxidation Cycles of Chemical Looping with Oxygen Uncoupling (CLOU)

Chemical Looping with Oxygen Uncoupling (CLOU) which uses solids oxygen carrier providing gaseous oxygen for combustion is an effective technology for CO2 capture with low-energy penalty. Oxygen carrier is a cornerstone for CLOU, because stable and high rate of oxygen release must be assured. In this work, a refractory brick was attempted as support for Cu-based oxygen carrier due to its high crushing strength and agglomeration resistance. Samples of Cu25RefBri, Cu30RefBri and Cu40RefBri with 25-40wt.% CuO loadings were prepared via successive impregnation and then calcined at 800oC for 6h in air atmosphere. Decomposition-oxidation cycles were performed in a TGA apparatus and a batch fluidized bed reactor at temperatures of T=900-950oC. The Cu25RefBri showed the highest rate of oxygen release among the stated oxygen carrier samples. This material, however, showed decrease of reactivity in either TGA or fluidized bed tests, mainly attributable to the formation of low-active CuAl2O4 spinel. The stable rate of oxygen release from Cu25RefBri could be as low as 0.2∙10-4 kgO2/(s∙kgOC), while the stable O2 concentration can be decreased to 0.8vol.% at 900oC, which is much lower that the equilibrium value at this temperature. In combination of hard agglomeration found at oxidation stage under 950oC, the attempted Cu25RefBri could not be considered as a suitable oxygen carrier for CLOU.

Effects of Coal Ash on CuO as an Oxygen Carrier for Chemical Looping with Oxygen Uncoupling

Chemical looping with oxygen uncoupling (CLOU) features the natural release of gaseous oxygen from oxygen carriers to efficiently burn solid fuels, producing a nearly nitrogen-free CO2 stream for c...

Comparative study of fuel-N and tar evolution in chemical looping combustion of biomass under both iG-CLC and CLOU modes

Chemical looping combustion (CLC) processes combined with CO2 sequestration and sustainable management of biomass represent a promising BioEnergy with Carbon Capture and Storage (BECCS) technology. One of the aspects to be considered in the combustion of biomass is the formation of NOx and the possible existence of tar in the gaseous product stream. The advantage of the CLC technology compared to other CO2 capture technologies is that only fuel-N contributes to nitrogen oxides formation. Moreover, scarce information is available about tar formation in CLC. Thus, this work focuses on these two aspects and compares the results obtained when two different chemical looping combustion modes are used, namely In Situ Gasification Chemical Looping Combustion (iG-CLC) and Chemical Looping with Oxygen Uncoupling (CLOU). Important differences were observed depending on the combustion mode. In both cases most of the fuel-N appeared as N2 in the fuel reactor. However, in iG-CLC more than 94% of the nitrogen measured in the fuel reactor was N2 independently of the biomass used. These percentages under the CLOU mode were lower. In this case, low amounts of N2O were also detected, although it decreased to almost zero at 850 °C. In the air reactor, NO was found and its concentration remained below the legal limit for NOx emissions in power installations with all the types of biomass tested and operating modes. Tar species and concentrations found at the fuel reactor outlet stream were different under the two combustion modes. About 2.5–3.7 g/Nm3 total tar could be found at 980 °C burning under iG-CLC mode, mostly naphthalene. On the contrary, insignificant tar amounts were found in CLOU.

Oxygen Uncoupling of Cu-Based Oxygen Carrier with the Presence of Coal Ash in Chemical Looping Process

Chemical looping with oxygen uncoupling (CLOU) represents a potentially high-efficiency approach to capture CO2 in the utilization of solid fuels. With the presence of complex mineral matters in solid fuels, the interaction between oxygen carrier and coal-derived ash in CLOU was necessary to be well understood. In this work, three typical coal ashes were selected and mixed with a Cu-based oxygen carrier (OC), and their impacts on the chemical and physical behavior of the oxygen carrier were studied comprehensively. The factor including coal ash types, ash content, CLOU cycle number, and reaction kinetics was evaluated. The results suggest that the presence of ash could lead to an obvious decrease of solid conversion during oxygen uncoupling. The most probable reason was attributed to the consumption of dissociate CuO with the formation of CuAl2O4. With the mass ratio of ash increased, the oxygen-releasing ability of samples was seen to become worse. Both of these effects tended to be a bit more serious af...

Evaluating Algae as an Alternative Fuel for Chemical Looping Combustion

Chemical Looping Combustion (CLC) and Chemical Looping with Oxygen Uncoupling (CLOU) are low-pollution energy generation techniques conventionally utilizing natural gas or synthetic gas as fuel. Using a redox reaction of metal oxides in dual fluidised beds, CO2 can be captured and prevented from entering the atmosphere at efficiencies up to 80% [4,8]. Algae is a sustainable source of biofuel with the additional benefit of carbon capture through photosynthesis [7]. This Meta-Study attempts to determine the viability of algae as CLC/CLOU reactor fuel for long term sustainable energy generation by identifying trends in different fuels and reactants to see if algae fuel can produce an acceptable output and identify areas of weakness. Energy balance calculations were performed as well as thermal energy output, processing energy and enthalpy values. Graciliara sp. and Chlorella Vulgaris made the most effective fuels for CLC and CLOU respectively due to the low amount of algae required to produce fuel. For CLC, 3.57kg Graciliara sp. produced 1kg fuel. For CLOU, 1.7kg Chlorella Vulgaris produced 1kg fuel. CLOU was the most mass efficient with an energy/mass efficiency ratio of 11600kJ/kg compared to CLC’s 15.7kJ/kg. The energy balance ratio analysis of the production of algal fuel also identified Chlorella Vulgaris as the best fuel, with an EBR of -0.4 in CLOU. In terms of evaluating output, CLOU's energy/mass efficiency ratio surpassed a modern coal plant [45], whose value was 2840 kJ/kg. The defining factor was the enthalpy of reaction.

Development of MgMnO3-δ as an oxygen carrier material for chemical looping combustion

Chemical looping combustion (CLC) is attracting attention as a promising technology for carbon dioxide separation. Oxygen carrier materials are the most important factor in determining the efficiency of CLC. In this paper, we present MgMnO3-δ with a defect cubic spinel structure as an oxygen carrier material with high efficiency, low cost, and stable properties. MgMnO3-δ has a non-stoichiometric oxygen content of MgMnO2.68. The reduced composition of MgMnO3-δ in H2, CO, or CH4 is a complete solid solution of (Mg,Mn)O. The redox reaction from MgMnO3-δ to (Mg,Mn)O is reversible and stable. Interestingly, MgMnO3-δ also shows a chemical looping oxygen uncoupling (CLOU) phenomenon and is reduced to MgMn2O4 and MgO in N2 at 900 °C. The oxygen transfer capacities of MgMnO3-δ under 15% H2/N2, 15% CO/CO2, 15% CH4/N2, and 15% CH4/CO2 are 8.34, 8.56, 8.42, and 8.74 wt%, respectively, at 900 °C. The oxygen transfer capacity was well maintained during the 5th redox cycle. No phase or structure changes or agglomeration occurred as the redox cycle number increased. Moreover, MgMnO3-δ has a high tolerance to carbon deposition when used in CO or CH4 fuels.

Process Simulation and Energy Analysis of Chemical Looping Combustion and Chemical Looping with Oxygen Uncoupling for Sawdust Biomass

AbstractThe integral part of chemical looping combustion (CLC) and chemical looping with oxygen uncoupling (CLOU) for solid fuels such as biomass consists of an interconnected fluidized air and fuel reactor. The heat recovery/loss in both reactors needs to be analyzed to commercialize these novel fuels based on CLC and CLOU processes. Here, complete process level modelling of CLC and CLOU process is attempted and explored using the ASPEN simulator with sawdust as the biomass. Initially, a benchmarking study of CLC is performed to validate the CO2, CO, and CH4 concentration in the fuel reactor and O2 and CO2 concentrations in the air reactor using 81.1 % Fe2O3 (oxygen carrier) as the reactive component. Thereafter energy analysis is carried out with sawdust biomass using the catalyst combination of 60 % Fe2O3−Al2O3 and 40 % CuO−ZrO2 for CLC and CLOU, respectively. In biomass, for CLOU a 51 % conversion is realized in the fuel reactor and 48 % is realized in the air reactor. The energy analysis gave a difference in energy output between CLC and CLOU of 43 Watts i.e., 201 Watts in CLOU and 158 Watts in CLC.

CuO supported on manganese ore as an oxygen carrier for chemical looping with oxygen uncoupling (CLOU)

The chemical-looping with oxygen uncoupling (CLOU) is a promising technology that could be used for combustion of solid fuels with inherent separation of carbon dioxide. In this work, manganese ore supported CuO (CMO) oxygen carrier was synthesized. The oxygen transport capacity (Ro) and the reaction reactivity of CMO were investigated in TGA. The CLOU tests with biochar as fuel were performed. The reaction reactivity with biochar was enhanced due to the synergistic effect between manganese ore and CuO, and a value of Ro, 3.31%, was observed in TGA at 950 °C after 15 redox cycles. In fluidized bed tests, CMO shows excellent cycle performance; full conversions of biochar and the values closed to 100% carbon capture efficiency were obtained in the temperature range of 850–950 °C. However, obvious sintering of CMO was observed when the operating temperature reached 1,000 °C, which was further verified by the SEM, BET and PSD results. From XRD patterns, CuMn2O4, CuO, Fe2O3, and SiO2 were detected in the fresh CMO sample. The presence of CuMn2O4 in fresh CMO sample indicated that manganese ore reacted with CuO during calcination. The CuMnO2, Cu2O and Mn3O4 observed in reduced CMO sample indicated that the gaseous oxygen was derived from CuO/Cu2O and CuMn2O4/CuMnO2 systems. The CMO was fully regenerated in air reactor after 10 cycles at 950 °C. In addition, CMO sample showed a higher crushing strength and magnetic property. These results indicated that CMO can be used as a good oxygen carrier candidate for CLOU below 950 °C.

Chemical looping with air separation (CLAS) in a moving bed reactor with CuO/ZrO2 oxygen carriers

Zirconia supported CuO oxygen carriers were prepared for carrying out chemical looping with oxygen uncoupling (CLOU) and chemical looping with air separation (CLAS) operation in a thermogravimetric analyzer (TGA), a fixed bed reactor and a moving bed reactor (MBR). In this study, graphite used as solid fuel for CLOU with CuO/ZrO2 oxygen carriers was also explored in a fixed bed reactor. 40 wt.% CuO/ZrO2 particles sintered at 1000 °C revealed reasonable reactivity without noticeable agglomeration as observed. For fixed bed operation, time required for graphite combustion with CuO/ZrO2 was decreased for experiments conducted at higher reaction temperatures. For experiments carried out in the moving bed reactor, the oxygen concentration and oxygen molar flow rate in the outlet stream can be adjusted by varying operating temperatures, CuO/ZrO2 flow rate, and carrier gas (N2) flow rate. Therefore, moving bed reactors are technically feasible to serve as fuel reactor for chemical looping with air separation.

CLOU process performance with a Cu-Mn oxygen carrier in the combustion of different types of coal with CO2 capture

The Chemical Looping with Oxygen Uncoupling (CLOU) process is a Chemical Looping Combustion (CLC) technology that allows the combustion of solid fuels with inherent CO2 separation by using oxygen carriers based on metal oxides. This technology has a low energy penalty and thus low CO2 capture costs. The oxygen carrier used in the CLOU process must be able to release gaseous oxygen, an aspect that limits the availability of metal oxides for this process. This work investigated the suitability of an oxygen carrier containing 34 wt% CuO and 66 wt% Mn3O4 (active phase Cu1.5Mn1.5O4) prepared by granulation regarding the CO2 capture, combustion efficiency and lifetime of the particles. The effect of the different types of coal (two sub-bituminous and a lignite) on combustion and CO2 capture efficiencies by CLOU was studied at different oxygen carrier to coal ratios in a continuous 1.5 kWth rig. It was found that full combustion could be reached regardless of the coal used. However, CO2 capture efficiencies were highly determined by coal rank. Finally, it was found that working with oxygen carrier to coal ratios higher than ϕ = 4, which corresponded to values of the variation of the oxygen carrier conversion lower than ΔXoc = 0.25, decreased the effect of chemical stress on the attrition rate. Therefore, it is clearly beneficial for the lifetime of oxygen carrier particles to operate with low variations of the oxygen carrier conversion (ΔXoc) between fuel and air reactors.

Coal combustion with a spray granulated Cu-Mn mixed oxide for the Chemical Looping with Oxygen Uncoupling (CLOU) process

The Chemical Looping with Oxygen Uncoupling (CLOU) process is a form of Chemical Looping Combustion (CLC) technology that enables the combustion of solid fuels by means of oxygen carriers that release gaseous oxygen in the fuel reactor, i.e. with oxygen uncoupling capability. In recent years, tests have found several Cu-based, Mn-based and mixed oxide oxygen carriers with suitable properties for the CLOU process. Among them, Cu-Mn mixed oxides show high reactivity and high O2 equilibrium concentration at temperatures of interest for coal combustion. In this work, proof of concept was demonstrated by burning coal with Cu-Mn mixed oxides in a 1.5kWth CLOU unit for the first time. The effect of fuel reactor temperature, solids circulation flow, fluidization agent in the fuel reactor (inert N2 or steam as gasifying agent), and excess air in the air reactor on combustion efficiency and CO2 capture rate was analysed. The results showed that high combustion efficiency and CO2 capture are feasible using this material at relatively low fuel reactor operating temperatures. Therefore, the developed Cu-Mn mixed oxide was a suitable material for use as an oxygen carrier for the CLOU combustion of solid fuels. Optimum operating conditions were determined for this oxygen carrier with regard to the oxygen circulation rate and air reactor conditions for the regeneration of the oxygen carrier.

Chemical looping with oxygen uncoupling (CLOU) and chemical looping combustion (CLC) using copper-enriched oxygen carriers supported on fly ash

An experimental investigation on chemical activity and stability of innovative CuO-based oxygen carriers (OC) supported on coal fly ash, towards Chemical Looping Combustion (CLC) and Chemical Looping Oxygen Uncoupling (CLOU) is presented. The materials were prepared by granulation of fine powders of CuO and fly ash (FA), with 40–60–80wt% CuO loading (Cu40FA, Cu60FA and Cu80FA), using a high shear granulator. CLC and CLOU activities were investigated in a thermogravimetric analyzer (TGA) in the presence of a reactive fuel or an inert atmosphere, respectively. A rather stable CLOU capacity (Ro-CLOU) in the range of 4–8g O2/100g OC was found over 42 redox cycles, in agreement with the stoichiometry of the prepared samples. CLC oxygen carrying capacity (Ro-CLC) with gaseous fuel, on the other hand, has evidenced a quick decline for the material with higher copper loading (80wt% CuO). Furthermore, both oxygen carriers with 40–60wt% CuO were tested for combustion of coal in a macro-TGA rig using CO2 as carrier gas and different OC:fuel ratios. First, a blank test in the absence of the OC was carried out to characterize the fast devolatilization and slow gasification reactions taking place due to the exposure of the fuel to high temperature and CO2-rich atmosphere. The comparison of the weight loss curve evolution with and without oxygen carrier, and the measured residual carbon after test, enabled to extract the CLOU effect for each combination of material/solid fuel.

Spray granulated Cu-Mn oxygen carrier for chemical looping with oxygen uncoupling (CLOU) process

One form of Chemical Looping Combustion (CLC) with CO2 capture as an alternative to the burning of solid fuels is the Chemical Looping with Oxygen Uncoupling (CLOU) process. The CLOU process requires metal oxides with O2 release capacity at temperatures that are suitable for solid fuel combustion, e.g. copper and manganese oxides. A Cu-Mn mixed oxide comprising 34wt% CuO and 66wt% Mn3O4 and prepared by fluidized bed granulation was analysed for use as an oxygen carrier for the CLOU process. TGA and batch fluidized bed reactors were used to investigate oxygen generation rates, agglomeration behaviour and oxygen carrier attrition. A medium volatile coal from South Africa and its char were used as fuel in a batch fluidized bed reactor in a temperature range of 800–930°C. The Cu-Mn oxygen carrier showed good release O2 rate and a high rate of oxygen transfer by direct gas-solid reaction. The presence of CO as a combustion product appeared only at low oxygen carrier to coal ratios. This material has the capacity to generate O2 at lower temperatures than needed for Cu-based oxygen carriers, which suggests that this material is suitable for work at lower temperatures in a fuel reactor with complete combustion of the fuel. The low attrition rate and attrition index, together with the stable crushing strength of the particles with redox cycles, make this Cu-Mn oxygen carrier suitable for operation in a continuous CLOU unit.

Evaluation of a hierarchically-structured CuO@TiO2-Al2O3 oxygen carrier for chemical looping with oxygen uncoupling

High redox reactivity as well as sufficient physical durability of the oxygen carrier (OC) is of critical importance for the successful implementation of chemical looping processes. In this work, CuO@TiO2-Al2O3 OC with hierarchical structure, which is a kind of CuO-rich, Al2O3-supported and TiO2-stablized ternary combined metal oxides system, was prepared by the self-assembly template combustion synthesis (SATCS) method. Performance of the rationally designed OC was cyclically tested with H2 in a thermogravimetric analyzer (TGA), as well as with coal in a batch fluidized bed reactor. TGA results showed that both the reduction and oxidation reactivity of the OC exhibited a reinforcing process during the first few cycles and then stabilized within the next dozens of cycles, and no obvious reactivity degradation phenomenon was observed. Reaction characteristics of the OC were further examined by reacting with coal in a fluidized bed reactor. Several critical performance indexes, like carbon conversion rate, oxygen release rate and combustion efficiency at different temperatures were calculated and compared. Mutual promotion relationship between carbon conversion rate of the coal and oxygen release rate of the OC was observed. Moreover, 20 cycles of redox process with anthracite were further conducted at 900°C to evaluate both the physical and chemical stability of the OC. Stable and high combustion efficiency (higher than 97.2%) was achieved during the cyclic fluidized bed test, and the subsequent physicochemical characterization indicated that neither CuAl2O4 phase was formed nor serious sintering problem occurred within the used OC samples. Thermo-mechanical analysis (TMA) results demonstrated relatively high transformation temperature of the OC, which explains well its superior anti-sintering property. All in all, the SATCS-derived CuO@TiO2-Al2O3 OC exhibited distinguished advantages of preventing the side reaction between CuO and Al2O3 to form copper aluminates as well as inhibiting the OC sintering, which could be a suitable OC candidate for commercial application in chemical looping with oxygen uncoupling (CLOU) processes.