Abstract: A composite amine absorbent to absorb at least one of CO2 and H2S in a gas includes: a chain monoamine; a diamine; a cyclic compound represented by the following chemical formula: where R1: any one of hydrogen, a hydrocarbon group having a carbon number of 1 to 4, and a hydroxyalkyl group, R2: oxygen or N—R3, and R3: any one of hydrogen, a hydrocarbon group having a carbon number of 1 to 4, and a hydroxyalkyl group; and water.

Abstract: A composite amine absorbent according to the present invention is an absorbent for absorbing CO2 or H2S, or both of CO2 and H2S in a gas. The absorbent is obtained by dissolving (1) a linear monoamine, (2) a diamine, and (3) propylene glycol alkyl ether, for example, represented by the following chemical formula (I) in water. In the composite amine absorbent, the components complexly interact, and the synergistic effect thereof provides good absorbability of CO2 or H2S, or both of CO2 and H2S and good releasability of CO2 or H2S absorbed during regeneration of the absorbent. Furthermore, the amount of water vapor in a reboiler 26 used during regeneration of the absorbent in a CO2 recovery unit 12 can be reduced.

Abstract: A CO2 recovery unit includes a CO2 absorber that brings a gas having a low CO2 concentration into countercurrent contact with a CO2 absorbent to remove CO2 from the gas. The CO2 recovery unit further includes a first absorbent circulation line that supplies a CO2 absorbent from a first CO2 absorption section as a first circulation solution to an upper side of a first CO2 absorption section; a second absorbent circulation line that supplies a CO2 absorbent from a second CO2 absorption section as a second circulation solution to an upper side of a second CO2 absorption section; and an absorbent discharge line that discharges a part of the first circulation solution from the first absorbent circulation line and supply the part of the first circulation solution as a discharged solution to the second absorbent circulation section.

Abstract: An absorbent liquid which absorbs at least one of CO2 and H2S from a gas, including a secondary linear monoamine; a tertiary linear monoamine or a sterically hindered primary monoamine; and a secondary cyclic diamine, wherein a concentration of each of the secondary linear monoamine, the tertiary linear monoamine or the sterically hindered primary monoamine; and the secondary cyclic diamine is less than 30% by weight.

Abstract: A geothermal heat utilization system (10) includes a pumping well (20), a water injection well (30), a pipe (13) having two ends which are immersed in water stored in the pumping well (20) and the water injection well (30) so as to connect the pumping well (20) and the water injection well (30) to each other, a pump (21) and a pump (31) which are respectively provided inside the pumping well (20) and the water injection well (30) and pump up stored water through the pipe (13), a valve (25) and a valve (35) which are respectively provided on a pressurization side of the pump (21) inside the pumping well (20) and a pressurization side of the pump (31) inside the water injection well (30), and a heat exchanger (14) which is configured to exchange heat with the pipe (13).

Abstract: A carbon dioxide recovery system includes: a heat exchanger that is disposed between a boiler and a desulfurization device, configured to cool exhaust gas flowing from the boiler to the desulfurization device, and configured to heat a heat medium; and a carbon dioxide recovery device that is configured to, when supplied with heat of the heat medium, separate and recover carbon dioxide from an absorber which has absorbed the carbon dioxide.

Abstract: An absorbent for absorbing CO2 or H2S, or both of CO2 and H2S in a gas contains, as components, (a) a secondary linear monoamine, (b) a tertiary linear monoamine, and (c) a secondary cyclic diamine. When the concentration of the secondary linear monoamine (a) is more than 30% by weight and less than 45% by weight and the concentration of the tertiary linear monoamine (b) is more than 15% by weight and less than 30% by weight, absorbability of CO2 or H2S, or both of CO2 and H2S is good, and releasability of CO2 or H2S that have been absorbed during regeneration of the absorbent is good. The amount of steam of a reboiler used during regeneration of the absorbent in a CO2 recovery unit can be thus reduced.

Abstract: A composite amine absorbent according to the present invention is an absorbent for absorbing CO2 or H2S, or both of CO2 and H2S in a gas. The absorbent is obtained by dissolving (1) a linear monoamine, (2) a diamine, and (3) propylene glycol alkyl ether, for example, represented by the following chemical formula (I) in water. In the composite amine absorbent, the components complexly interact, and the synergistic effect thereof provides good absorbability of CO2 or H2S, or both of CO2 and H2S and good releasability of CO2 or H2S absorbed during regeneration of the absorbent. Furthermore, the amount of water vapor in a reboiler 26 used during regeneration of the absorbent in a CO2 recovery unit 12 can be reduced.

Abstract: An absorbent liquid which absorbs at least one of CO2 and H2S from a gas, including a secondary linear monoamine; a tertiary linear monoamine or a sterically hindered primary monoamine; and a secondary cyclic diamine, wherein a concentration of each of the secondary linear monoamine, the tertiary linear monoamine or the sterically hindered primary monoamine; and the secondary cyclic diamine is less than 30% by weight.

Abstract: An absorbent liquid which absorbs at least one of CO2 and H2S from a gas, including a secondary linear monoamine; a tertiary linear monoamine or a sterically hindered primary monoamine; and a secondary cyclic diamine, wherein a concentration of each of the secondary linear monoamine, the tertiary linear monoamine or the sterically hindered primary monoamine; and the secondary cyclic diamine is less than 30% by weight.

Abstract: A geothermal heat utilization system includes a heat source well facility, a heat source device having a refrigeration cycle including a compressor, a condenser, an expanded portion, and an evaporator, a primary refrigerant circuit that is connected to a first unit which is one of the condenser and the evaporator of the heat source device, heat exchange being able to be performed between the first unit and the well-side pipe, a secondary refrigerant circuit that is connected to a second unit which is the other of the condenser and the evaporator of the heat source device, heat exchange being able to be performed between the second unit and a load, and a mode switching unit that switches between a cold heat storage operation mode in which the primary refrigerant circuit is connected to the evaporator and the secondary refrigerant circuit is connected to the condenser and a cold heat discharge operation mode in which the primary refrigerant circuit is connected to the condenser and the secondary refrigerant cir

Abstract: This invention provides a CO2 desorption catalyst that has an excellent CO2 desorption activity and that can be used to replace metal filler. This invention provides a CO2 desorption catalyst comprising an inorganic powder or inorganic powder compact, the inorganic powder or inorganic powder compact having a BET specific surface area of 7 m2/g or more.

Abstract: A geothermal heat utilization system (10) includes a pumping well (20), a water injection well (30), a pipe (13) having two ends which are immersed in water stored in the pumping well (20) and the water injection well (30) so as to connect the pumping well (20) and the water injection well (30) to each other, a pump (21) and a pump (31) which are respectively provided inside the pumping well (20) and the water injection well (30) and pump up stored water through the pipe (13), a valve (25) and a valve (35) which are respectively provided on a pressurization side of the pump (21) inside the pumping well (20) and a pressurization side of the pump (31) inside the water injection well (30), and a heat exchanger (14) which is configured to exchange heat with the pipe (13).

Abstract: An absorbing liquid which absorbs the CO2 or H2S or both contained in a gas, and which comprises 1) at least one tertiary-monoamine main agent selected from a tertiary-monoamine group and 2) at least one secondary-diamine first additive selected from a secondary-diamine group, the secondary-diamine concentration being within the range of 0.05 to 0.5 in terms of the additive concentration index represented by the following expression (I). (Additive concentration index)=[(secondary-diamine acid dissociation index) (pKa)/(tertiary-monoamine acid dissociation index) (pKa)] (index ratio)×[(secondary-diamine molar concentration) (mol/L)/(tertiary-monoamine molar concentration) (mol/L)] (molar ratio) (I).

Abstract: An absorbent is prepared by dissolving in water 1) monoethanolamine (MEA) and 2) a primary amine represented by the following formula (1) and having high steric hindrance. Releasability of CO2 or H2S during regeneration of the absorbent is thereby improved, and the amount of water vapor used during regeneration of the absorbent in a facility for recovering CO2 or H2S can be reduced. R1 to R3: H or a hydrocarbon group having 1 to 3 carbon atoms, at least one of R1 to R3 being a hydrocarbon.

Abstract: A geothermal heat utilization system includes a heat source well facility, a heat source device having a refrigeration cycle including a compressor, a condenser, an expanded portion, and an evaporator, a primary refrigerant circuit that is connected to a first unit which is one of the condenser and the evaporator of the heat source device, heat exchange being able to be performed between the first unit and the well-side pipe, a secondary refrigerant circuit that is connected to a second unit which is the other of the condenser and the evaporator of the heat source device, heat exchange being able to be performed between the second unit and a load, and a mode switching unit that switches between a cold heat storage operation mode in which the primary refrigerant circuit is connected to the evaporator and the secondary refrigerant circuit is connected to the condenser and a cold heat discharge operation mode in which the primary refrigerant circuit is connected to the condenser and the secondary refrigerant cir

Abstract: An absorbent liquid which absorbs at least one of CO2 and H2S from a gas, including a secondary linear monoamine; a tertiary linear monoamine or a sterically hindered primary monoamine; and a secondary cyclic diamine, wherein a concentration of each of the secondary linear monoamine, the tertiary linear monoamine or the sterically hindered primary monoamine; and the secondary cyclic diamine is less than 30% by weight.

Abstract: A CO2 recovery apparatus capable of recovering CO2 by using only a low-quality exhaust heat at 100° C. or less is provided. The present invention includes an absorption tower for allowing a basic aqueous solution to absorb CO2; and a regenerator for heating a basic aqueous solution with CO2 absorbed therein using a heating medium having a temperature of 100° C. or less, thereby desorbing CO2.

Abstract: This invention provides a CO2 desorption catalyst that has an excellent CO2 desorption activity and that can be used to replace metal filler. This invention provides a CO2 desorption catalyst comprising an inorganic powder or inorganic powder compact, the inorganic powder or inorganic powder compact having a BET specific surface area of 7 m2/g or more.

Abstract: A CO2 recovery unit for recovery and removal of CO2 in a CO2-containing flue gas using a CO2-absorbent within a CO2 absorber is provided. The CO2 absorber includes a CO2-absorbing unit for the absorption of CO2 in a CO2-containing flue gas, a main water rinsing unit that is provided on a gas flow downstream side of the CO2-absorbing unit and that uses rinsing water to recover the accompanying CO2-absorbent while cooling decarbonated flue gas, and a preliminary water rinsing unit provided between the CO2-absorbing unit and the main water rinsing unit. A portion of the rinsing water containing the CO2-absorbent that is circulated in the main water rinsing unit is withdrawn and is subjected to preliminary water rinsing in the preliminary water rinsing unit. The preliminary rinsing water is allowed to meet with a CO2-absorbent while allowing the rinsing water to directly flow down on the CO2-absorbing unit side.