Carbon dioxide recovery system
A carbon dioxide recovery system includes: an adsorber configured to adsorb and desorb carbon dioxide; a supply channel through which supply gas passes; a storage section configured to store carbon dioxide desorbed from the adsorber; and a gas supply section supplying carbon dioxide stored in the storage section to the adsorber. The carbon dioxide recovery system is operated in an adsorption mode, a desorption mode or in a desorption preparation mode. In the adsorption mode, the adsorber adsorbs CO 2 contained in the supply gas supplied through the supply channel. In the desorption mode, the adsorber desorbs the adsorbed CO 2 , and the storage section stores CO 2 desorbed from the adsorber. In the desorption preparation mode, the gas supply section supplies CO 2 stored in the storage section to the adsorber during a time from an end of the adsorption mode to a start of the desorption mode.
1 . A carbon dioxide recovery system for separating and recovering CO 2 from a supply gas containing CO 2 and non-CO 2 gas other than CO 2 , the carbon dioxide recovery system comprising:
an adsorber configured to adsorb or desorb CO 2 ;
a supply channel through which the supply gas passes;
a storage section configured to store CO 2 desorbed from the adsorber;
a gas supply section configured to supply CO 2 stored in the storage section to the adsorber; and
a throttle valve provided in the supply channel, wherein
the carbon dioxide recovery system is configured to set:
an adsorption mode in which the adsorber adsorbs CO 2 contained in the supply gas supplied through the supply channel;
a desorption mode in which CO 2 adsorbed by the adsorber is desorbed and the storage section stores the desorbed CO 2 desorbed from the adsorber; and
a desorption preparation mode in which the gas supply section supplies CO 2 stored in the storage section to the adsorber, during a period from an end of the adsorption mode to a start of the desorption mode, wherein during the desorption preparation mode, the throttle valve has a smaller opening degree than an opening degree in the adsorption mode, and
the throttle valve is located downstream of the adsorber in a flow direction of the gas when CO 2 stored in the storage section is supplied to the adsorber in the desorption preparation mode.
2 . The carbon dioxide recovery system according to claim 1 , wherein the adsorber is configured to adsorb or desorb CO 2 in accordance with a variation in a CO 2 partial pressure inside the adsorber, the carbon dioxide recovery system further comprising
a pressure adjuster configured to adjust the CO 2 partial pressure inside the adsorber, and
the pressure adjuster adjusts the CO 2 partial pressure inside the adsorber to a predetermined pressure in order to cause the adsorber to adsorb CO 2 in the adsorption mode, and to adjust the CO 2 partial pressure inside the adsorber to be lower than the predetermined pressure in order to cause the adsorber to desorb CO 2 .
3 . The carbon dioxide recovery system according to claim 1 , further comprising:
an auxiliary storage section configured to store discharged gas discharged from the adsorber when the CO 2 is supplied by the gas supply section in the desorption preparation mode, wherein
the auxiliary storage section is configured to cause the discharged gas stored in the auxiliary storage section to merge with the supply gas and is supplied to the adsorber in the adsorption mode.
4 . The carbon dioxide recovery system according to claim 1 , wherein
a plurality of the adsorbers are provided,
when a specific adsorber operates in the adsorption mode, the other adsorber other than the specific adsorber operates in the desorption preparation mode or the desorption mode, and
a discharged gas, discharged from the other adsorber operating in the desorption preparation mode along with a supply of CO 2 by the gas supply section, is mixed with the supply gas and joins the specific adsorber operating in the adsorption mode.
5 . The carbon dioxide recovery system according to claim 3 , further comprising:
a check valve provided upstream in a flow direction of the supply gas from a merge point where the discharged gas merges with the supply gas in the supply channel, and
the check valve is configured to allow the gas flowing along the flow of the supply gas to pass therethrough, and to shut a flow of the gas flowing against the flow of the supply gas.
6 . The carbon dioxide recovery system according to claim 1 , wherein
the desorption mode is performed for an execution time that is longer than an execution time of the desorption preparation mode.
7 . A carbon dioxide recovery system for separating and recovering CO 2 from a supply gas containing CO 2 and non-CO 2 gas other than CO 2 , the carbon dioxide recovery system comprising:
an adsorber configured to adsorb or desorb CO 2 ;
a supply channel through which the supply gas passes;
a storage tank configured to store CO 2 desorbed from the adsorber;
a gas supply device configured to supply CO 2 stored in the storage section to the adsorber;
a throttle valve provided in the supply channel; and
a controller configured to switch an operation mode, among an adsorption mode in which the adsorber adsorbs CO 2 contained in the supply gas supplied through the supply channel, a desorption mode in which CO 2 adsorbed by the adsorber is desorbed and the storage tank stores therein the desorbed CO 2 desorbed from the adsorber, and a desorption preparation mode in which the gas supply device supplies CO 2 stored in the storage tank to the adsorber during a period from an end of the adsorption mode to a start of the desorption mode, wherein during the desorption preparation mode, the throttle valve has a smaller opening degree than an opening degree in the adsorption mode, wherein
the controller controls the gas supply device to switch the desorption mode from the desorption preparation mode, in response to a result in which the controller determines that a predetermined condition is satisfied, and
the throttle valve is located downstream of the adsorber in a flow direction of the gas when CO 2 stored in the storage section is supplied to the adsorber in the desorption preparation mode.
8 . The carbon dioxide recovery system according to claim 7 , further comprising:
a gas concentration sensor configured to detect a CO 2 concentration of the discharged gas discharged from the adsorber along with the supply of CO 2 by the gas supply section in the desorption preparation mode, wherein
the controller controls the gas supply device to switch the desorption mode from the desorption preparation mode, in response to a result in which the controller determines that the CO 2 concentration detected by the gas concentration sensor reaches or exceeds a predetermined concentration in the desorption preparation mode.
9 . The carbon dioxide recovery system according to claim 7 , further comprising:
a gas concentration sensor configured to detect a non-CO 2 gas concentration of the discharged gas discharged from the adsorber along with the supply of CO 2 by the gas supply section in the desorption preparation mode, wherein
the controller controls the gas supply device to switch the desorption mode from the desorption preparation mode, in response to a result in which the controller determines that the non-CO 2 gas concentration detected by the gas concentration sensor becomes below a predetermined concentration.
10 . The carbon dioxide recovery system according to claim 7 , wherein
the controller controls the gas supply device to switch the desorption mode from the desorption preparation mode, in response to a result in which the controller determines that a lapse time from the start of the desorption preparation mode reaches a predetermined time.
11 . The carbon dioxide recovery system according to claim 10 , wherein
upon transition to the desorption mode, the controller controls the gas supply device to lower the CO 2 partial pressure in the adsorber compared to the adsorption mode, and supplies the CO 2 desorbed from the adsorber to the storage section.