Batch fluidized bed test of SATS-derived CaO/TiO2–Al2O3 sorbent for calcium looping

Abstract

High CO2 capture capacity and attrition resistance are of great significance for CaO-based CO2 sorbents during successive carbonation/calcination cycles. In this study, a novel self-assembly template synthesis (SATS) method is proposed to manufacture a hierarchical structure CaO/TiO2–Al2O3 sorbent, where Ca-rich, Al2O3-supported and TiO2-stabilized in a core–shell microarchitecture. Preparation experiments, including crushing strength and attrition tests of fresh CaO-based CO2 sorbents, confirm the operational feasibility of sorbents to conduct carbonation/calcination cycles in a batch fluidized bed. After 10 cyclic tests, it is interesting that CaO/TiO2–Al2O3 sorbent achieves superior CO2 capture capacity and favorable cyclic stability of 0.78mol CO2/mol CaO, which maintains almost 100% of the initial CO2 capture amount. As for attrition resistance, CaO/TiO2–Al2O3 sorbent performs an appreciable crushing strength of 1.46N and shows a low attrition loss with almost no variation of particle size distribution even after 10 cycles. All the tests are also conducted for CaO and CaO/Al2O3 sorbents for comparison, and the CO2 capture capacity and attrition resistance of the SATS-derived CaO/TiO2–Al2O3 sorbent are highlighted. In addition, it is concluded that the CaO/TiO2–Al2O3 sorbent performs prospective raw material cost in repeated carbonation/calcination cycles, which provides a possible path to realize industrial application.