Investigation of modifying anti-sintering and oxygen uncoupling performance of CuO/TiO2 by MgO addition: Novel oxygen carrier.

• For its high mechanical strength, TiO 2 selected to support CuO oxygen carrier. • Various MgO ratios added to CuO/TiO 2 to enhance its poor anti-sintering. • Oxygen carriers characterization revealed that MgO enhanced anti-sintering. • Fixed bed and TGA used to investigate the oxygen uncoupling reactivity. • High MgO ratios have stable reactivity, high TiO 2 was better first but declined. Copper-based oxygen carrier is a strong candidate for commercial-scale chemical looping technology due to its high reactivity. In contrast, it has poor attrition and sintering resistance. Several supports have been used so far; however, they suffered from a high attrition rate under continuous operation. TiO 2 has not been tested under continuous operation due to its poor sintering resistance, although it has the highest crushing strength. The novelty of this study is to use CuO/TiO 2 and look to enhance its anti-sintering by MgO addition. Incipient wet impregnation method was used to synthesize 60 wt%CuO/40 wt%support (support:40 %TiO 2 , 30 %TiO 2 /10 %MgO, 20 %TiO 2 /20 %MgO, 10 %TiO 2 /30 %MgO, and 40 %MgO) calcinated at 890 °C for 7 h. XRD, XPS, SEM, and BET surface area have been used to characterize oxygen carriers. Oxygen uncoupling performance has been tested on a TGA at 920 °C through 10 cycles. The oxygen uncoupling capacity of all samples was around the theoretical value (6%); results also showed better uncoupling reactivity with a higher load of TiO 2 , while the sintering was also higher, as disclosed by SEM and BET. A fixed bed system was used for additional investigation; its results were almost identical to TGA. The results ascribed to high oxygen vacancies and copper concentration on the surface with a higher load of TiO 2. So, all oxygen carriers have additionally calcinated for 48 h at 920 °C and tested again in a fixed bed, then the effect of sintering was dominant, and the reactivity was uniformly better with a higher load of MgO and sintering resistance. [ABSTRACT FROM AUTHOR]