Enhanced CO2 Capture Durability and Mechanical Properties Using Cellulose-Templated CaO-Based Pellets with Steam Injection during Calcination

Abstract

Cellulose-templated CaO-based pellets were prepared via an extrusion–spheronization method. However, the CO2 capture capacity of the modified sorbents still deteriorated rapidly after multiple cycles, and the mechanical properties were also reduced. Steam injection during calcination was conducted to enhance the CO2 capture performance of the sorbents. The modified pellets with 10 vol % steam injection present a faster carbonation rate compared to sorbents calcined under higher steam concentrations. A CO2 uptake of 0.32 g/g was obtained after 20 cycles, 133 and 60% higher than the raw sorbent and modified sorbent without steam reactivation. Moreover, the simultaneous thermal and atmosphere-induced sintering resulted in a nearly 4 times enhancement of the mechanical strength of the sorbents from 3.9 to 14.7 N. Under the harsh environment (calcined at 950 °C), the presence of steam further aggravated the sintering of the sorbent, resulting in a dramatic decrease in CO2 uptake.