Carbon dioxide adsorbent and method for manufacturing same, as well as carbon dioxide separation system

A method for manufacturing a carbon dioxide adsorbent includes: forming a kneaded product containing a hydrophilic fiber, a powdery porous material, and an aqueous hydrophilic binder dispersion into particles and drying the particles to generate porous material particles containing the hydrophilic fiber and the powdery porous material combined by the hydrophilic binder; and preparing an aqueous amine solution having an amine concentration of 5% or more and 70% or less and a temperature of 10° C. or higher and 100° C. or lower, impregnating the aqueous amine solution into the porous material particles, and aeration-drying the porous material particles impregnating the amine. The carbon dioxide adsorbent contains the porous material particles and the amine carried by the porous material particles, the porous material particles containing the hydrophilic fiber and the powdery porous material combined by the hydrophilic binder.