Preparation and performance of amine-based polyacrylamide composite beads for CO2 capture

The macropore composite beads were prepared as CO2 adsorbent by polymerization of polyacrylamide and impregnation of 1,2-epoxyhexane functionalized poly(ethyleneimine). The consecutive CO2 adsorption-desorption tests were performed at 1 bar in the range of 50-125 °C. The time required to achieve 90% CO2 uptake (2.64 mmol·g−1) is less than 10 min, and 90% CO2 desorption can be realized within 11 min. After 50 cycles of adsorption-desorption, the adsorption capacity declines 9.2 wt.%. According to the adsorption-desorption thermodynamics without consideration of the heat recovery, the calculated regeneration heat is 2.2 MJ·kg−1(CO2). The attrition resistance of the spherical beads was tested in a bubbling fluidized-bed reactor, and the attrition ratio is 0.30 wt.%·h−1 at 130 °C. These results indicate that the synthesized adsorbent possesses high adsorption efficiency, low desorption energy, and good attrition resistance performance, showing good application prospects for CO2 capture in fluidized-bed reactors.