Abstract: A carbon dioxide adsorbent including silica gel and an amine compound carried by the silica gel. The silica gel has a spherical shape, a particle size ranging from 1 mm to 5 mm inclusive, an average pore diameter ranging from 10 nm to 100 nm inclusive, a pore volume ranging from 0.1 cm3/g to 1.3 cm3/g inclusive, and a waterproof property N that is defined by an expression (1) and that is not lower than 45%, N=(W/W0)×100??(1) where N is the waterproof property in percentage (%) of the silica gel, W0 is a total number of particles of the silica gel immersed in water, W is a number of particles of the silica gel not subjected to breakage out of W0.

Abstract: 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.

Abstract: A carbon dioxide adsorbent including silica gel and an amine compound carried by the silica gel. The silica gel has a spherical shape, a particle size ranging from 1 mm to 5 mm inclusive, an average pore diameter ranging from 10 nm to 100 nm inclusive, a pore volume ranging from 0.1 cm3/g to 1.3 cm3/g inclusive, and a waterproof property N that is defined by an expression (1) and that is not lower than 45%, N=(W/W0)×100??(1) where N is the waterproof property in percentage (%) of the silica gel, W0 is a total number of particles of the silica gel immersed in water, W is a number of particles of the silica gel not subjected to breakage out of W0.

Abstract: A method for manufacturing a carbon dioxide adsorbent includes preparing an amine aqueous solution having an amine compound concentration ranging from 5% to 70% inclusive and a temperature ranging from 10° C. to 100° C. inclusive, impregnating silica gel with the amine aqueous solution, and aeration-drying the silica gel carrying the amine compound. The silica gel has a particle size ranging from 1 mm to 5 mm inclusive, an average pore diameter ranging from 10 nm to 100 nm inclusive, and a pore volume ranging from 0.1 cm3/g to 1.3 cm3/g inclusive.

Abstract: An acid gas adsorbent that reversibly adsorbs an acid gas contained in a gas to be processed includes: metal oxide porous material particles; and an acid gas adsorbing agent with which the porous material particles are impregnated. Each of the porous material particles has binary pores including: a mesopore having a pore diameter in a nanometer region of 2 nm or more and 200 nm or less; and a macropore having a pore diameter in a micrometer region of more than 0.2 ?m. The macropore is an empty pore, and the mesopore is filled with the acid gas adsorbing agent.

Abstract: 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.

Abstract: A method for manufacturing a carbon dioxide adsorbent includes preparing an amine aqueous solution having an amine compound concentration ranging from 5% to 70% inclusive and a temperature ranging from 10° C. to 100° C. inclusive, impregnating silica gel with the amine aqueous solution, and aeration-drying the silica gel carrying the amine compound. The silica gel has a particle size ranging from 1 mm to 5 mm inclusive, an average pore diameter ranging from 10 nm to 100 nm inclusive, and a pore volume ranging from 0.1 cm3/g to 1.3 cm3/g inclusive.