Robust Immobilized Amine CO2 Sorbent Pellets Utilizing a Poly(Chloroprene) Polymer Binder and Fly Ash Additive

Pelletization of ca. 50 wt % amine/silica carbon dioxide sorbents was achieved with the novel combination of fly ash (FA) as a strength additive and hydrophobic poly(chloroprene) (PC) as a binder. The PC content and overall synthesis procedure of these materials were optimized to produce pellets, labeled as FA/E100-S_(20/80)_12.2, with the highest ball-mill attrition resistance (<0.5 wt % by fines, 24 h) and maximum CO2 capture capacity of 1.78 mmol CO2 g−1. The strength of the pellets was attributed to hydrogen-bonding of the relatively homogeneous PC network with the interlocked FA and BIAS particles (DRIFTS, SEM-EDS). The low degradation of 3–4 % in the pellet's CO2 capture capacity under both dry TGA (7.5 h) and practical fixed-bed (6.5 h dry; 4.5 h humid,≈5 vol % H2O) CO2 adsorption–desorption conditions highlights the pellet's excellent cyclic stability. These robust pellet characteristics make PC/FA/sorbent materials promising for commercial scale, point-source CO2 capture.