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 separation recovery method includes: bringing a particulate carbon dioxide adsorbent and a treatment target gas containing carbon dioxide into contact with each other to make the carbon dioxide adsorbent adsorb the carbon dioxide contained in the treatment target gas; and bringing the carbon dioxide adsorbent which has adsorbed the carbon dioxide and superheated steam into contact with each other to desorb the carbon dioxide from the carbon dioxide adsorbent and thereby regenerate the carbon dioxide adsorbent, and recovering the desorbed carbon dioxide. A saturation temperature of the superheated steam which is brought into contact with the carbon dioxide adsorbent is not more than a temperature of the carbon dioxide adsorbent which contacts the superheated steam. The regenerated carbon dioxide adsorbent is utilized for adsorption of the carbon dioxide again without being subjected to a drying step.

Abstract: A carbon dioxide separation recovery method includes: bringing a particulate carbon dioxide adsorbent and a treatment target gas containing carbon dioxide into contact with each other to make the carbon dioxide adsorbent adsorb the carbon dioxide contained in the treatment target gas; and bringing the carbon dioxide adsorbent which has adsorbed the carbon dioxide and desorption steam into contact with each other to desorb the carbon dioxide from the carbon dioxide adsorbent, and thereby, regenerate the carbon dioxide adsorbent and recover the desorbed carbon dioxide. The step of recovering the carbon dioxide includes utilizing a recovery gas as a heat source of a heat exchanger, the recovery gas containing the desorption steam which has contacted the carbon dioxide adsorbent and the carbon dioxide which has been desorbed from the carbon dioxide adsorbent.

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 carbon dioxide separation recovery method includes: bringing a particulate carbon dioxide adsorbent and a treatment target gas containing carbon dioxide into contact with each other to make the carbon dioxide adsorbent adsorb the carbon dioxide contained in the treatment target gas; and bringing the carbon dioxide adsorbent which has adsorbed the carbon dioxide and superheated steam into contact with each other to desorb the carbon dioxide from the carbon dioxide adsorbent and thereby regenerate the carbon dioxide adsorbent, and recovering the desorbed carbon dioxide. A saturation temperature of the superheated steam which is brought into contact with the carbon dioxide adsorbent is not more than a temperature of the carbon dioxide adsorbent which contacts the superheated steam. The regenerated carbon dioxide adsorbent is utilized for adsorption of the carbon dioxide again without being subjected to a drying step.

Abstract: A carbon dioxide separation recovery method includes: bringing a particulate carbon dioxide adsorbent and a treatment target gas containing carbon dioxide into contact with each other to make the carbon dioxide adsorbent adsorb the carbon dioxide contained in the treatment target gas; and bringing the carbon dioxide adsorbent which has adsorbed the carbon dioxide and desorption steam into contact with each other to desorb the carbon dioxide from the carbon dioxide adsorbent, and thereby, regenerate the carbon dioxide adsorbent and recover the desorbed carbon dioxide. The step of recovering the carbon dioxide includes utilizing a recovery gas as a heat source of a heat exchanger, the recovery gas containing the desorption steam which has contacted the carbon dioxide adsorbent and the carbon dioxide which has been desorbed from the carbon dioxide adsorbent.

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.

Abstract: A carbon dioxide separation and recovery system includes: an adsorption reactor, which adsorbs, by an adsorbent, carbon dioxide contained in a to-be-treated gas, discharges the to-be-treated gas from which the carbon dioxide has been removed, and discharges the adsorbent that has adsorbed the carbon dioxide; a desorption reactor, which receives the adsorbent discharged from the adsorption reactor, condenses desorbing steam on the adsorbent to cause carbon dioxide to desorb from the adsorbent, and then discharges the adsorbent; and an adsorbent dryer, which receives the adsorbent discharged from the desorption reactor, dries the adsorbent until a water content ratio thereof becomes a predetermined value greater than or equal to a water content ratio limit by causing, with use of a drying gas, condensation water contained in the adsorbent to evaporate as steam, and then discharges the adsorbent.

Abstract: A carbon dioxide recovery system includes: a desorption vessel configured to cause carbon dioxide to be desorbed from an absorbent; a carbon dioxide holder connected to desorption vessel via the desorption vessel and carbon dioxide recovery pipe; a pump configured to feed gas in the desorption vessel to the carbon dioxide holder via carbon dioxide recovery pipe; and at least one pressure switching device including at least one stage of hopper, an inlet valve configured to open and close the hopper's inlet port, an outlet valve configured to open and close the hopper's outlet port, an exhaust pipe connected to the hopper and configured to exhaust the hopper, an exhaust valve configured to open and close the exhaust pipe, an air supply pipe connected to the hopper and configured to supply carbon dioxide to the hopper, and an air supply valve configured to open and close the air supply pipe.

Abstract: A treatment tower of a carbon dioxide separation system includes a treatment container of a tower shape, having inner space which is virtually dividable into a regeneration treatment chamber, drying treatment chamber, and adsorption treatment chamber arranged in this order from the top to the bottom, by two hindrances which are upper and lower hindrances and hinder the downward movement of the adsorbent while maintaining the bedded (layered) flow of the adsorbent, a first passage member formed with ejection holes which eject a gas used in a treatment in each of the treatment chambers to a lower portion of each of the treatment chambers, and a second passage member formed with a gas discharge hole which discharges the gas having contacted the adsorbent from an upper portion of each of the treatment chambers. In the two treatment chambers on the lower side, gas discharge holes are formed below the hindrances.

Abstract: A carbon dioxide separation and recovery system includes an adsorption tower, a regeneration tower, and a drying tower. The adsorption tower causes a target gas to contact an adsorbent to adsorb carbon dioxide contained in the target gas to the adsorbent. The regeneration tower causes a normal-pressure wet gas which is a gas mixture of the carbon dioxide and steam to contact the adsorbent having adsorbed the carbon dioxide to desorb the carbon dioxide from the adsorbent. The drying tower dries the adsorbent. In addition, the carbon dioxide separation and recovery system includes a compressor that compresses the carbon dioxide, and an ejector that expands the carbon dioxide discharged from the compressor while suctioning negative-pressure steam, to generate the wet gas.

Abstract: A treatment tower of a carbon dioxide separation system includes a treatment container of a tower shape, having inner space which is virtually dividable into a regeneration treatment chamber, drying treatment chamber, and adsorption treatment chamber arranged in this order from the top to the bottom, by two hindrances which are upper and lower hindrances and hinder the downward movement of the adsorbent while maintaining the bedded (layered) flow of the adsorbent, a first passage member formed with ejection holes which eject a gas used in a treatment in each of the treatment chambers to a lower portion of each of the treatment chambers, and a second passage member formed with a gas discharge hole which discharges the gas having contacted the adsorbent from an upper portion of each of the treatment chambers. In the two treatment chambers on the lower side, gas discharge holes are formed below the hindrances.

Abstract: A carbon dioxide separation and recovery system includes an adsorption tower, a regeneration tower, and a drying tower. The adsorption tower causes a target gas to contact an adsorbent to adsorb carbon dioxide contained in the target gas to the adsorbent. The regeneration tower causes a normal-pressure wet gas which is a gas mixture of the carbon dioxide and steam to contact the adsorbent having adsorbed the carbon dioxide to desorb the carbon dioxide from the adsorbent. The drying tower dries the adsorbent. In addition, the carbon dioxide separation and recovery system includes a compressor that compresses the carbon dioxide, and an ejector that expands the carbon dioxide discharged from the compressor while suctioning negative-pressure steam, to generate the wet gas.

Abstract: A carbon dioxide separation and recovery system includes: an adsorption reactor, which adsorbs, by an adsorbent, carbon dioxide contained in a to-be-treated gas, discharges the to-be-treated gas from which the carbon dioxide has been removed, and discharges the adsorbent that has adsorbed the carbon dioxide; a desorption reactor, which receives the adsorbent discharged from the adsorption reactor, condenses desorbing steam on the adsorbent to cause carbon dioxide to desorb from the adsorbent, and then discharges the adsorbent; and an adsorbent dryer, which receives the adsorbent discharged from the desorption reactor, dries the adsorbent until a water content ratio thereof becomes a predetermined value greater than or equal to a water content ratio limit by causing, with use of a drying gas, condensation water contained in the adsorbent to evaporate as steam, and then discharges the adsorbent.