Steam-Stable BIAS Pellets for CO2 Capture Under Practical Conditions

Pelletization of basic immobilized amine sorbent (BIAS) particles is required to improve their mechanical strength and facilitate their practical CO2 capture application under fixed or dynamic reactor conditions. Herein, we utilized two methods to prepare amine-functionalized BIAS pellets. Method (ii-a) involved combining latex polychloroprene (PC)/polyamine solutions with fly ash (FA)/BIAS powder to form sorbent pellets. Alternatively, method (ii-b) entailed shaping and drying wet pastes of binder solution plus FA/SiO2 powder into pellet supports. These supports were then functionalized with leach-resistant polyethylenimine MW = 800 (PEI800)/N-N-diglycidyl-4-glycidyloxyaniline (tri-epoxide cross-linker, E3) or ethylenamine E100/E3 mixtures. All pellets were screened for CO2 capture by thermogravimetric analysis (dry 14% CO2/N2, 55–75 °C), H2O stability by accelerated water washing, and mechanical strength by crush and ball-mill attrition testing. The mechanism of superior method (ii-b) pellet formation w...