High-Efficiency CaO-Based Sorbent Modified by Aluminate Cement and Organic Fiber Through Wet Mixing Method

Abstract

CaO-based sorbents are usually used for high-temperature postcombustion CO2 capture through cyclic carbonation–calcination reactions. However, the rapid decay of sorbent reactivity limits their application. In this study, three types of CO2 sorbent precursors, namely Ca(CH3COO)2, Ca(OH)2, and CaCO3, are used to produce initial CaO-based sorbents. Then, the initial sorbents are mixed with aluminate cement and organic fibers at an appropriate ratio to synthesize high-efficiency sorbents. Our results show that the cyclic performance of the sorbent that decomposed from Ca(CH3COO)2 is better than that decomposed from Ca(OH)2 and CaCO3. It is mainly because the sorbent pore structure becomes much developed after Ca(CH3COO)2 decomposition. Furthermore, when mixed with aluminate cement, the CaO-based sorbent achieves a good performance for CO2 capture because of the formation of the sorbent skeleton Ca12Al14O33. For example, when the mass ratio of Ca(OH)2 to aluminate cement is set as 1:1, CaO conversion achieves...