CO2 separation device in gas and its membrane separation method and method for controlling membrane separation of CO2 separation device in gas
A source gas introduction line for introducing source gas containing CO 2 , a first membrane separator for membrane-separating CO 2 from source gas, a first permeable gas discharge line for discharging first permeable gas permeated by membrane separation of the first membrane separator, a first non-permeable gas discharge line for discharging first non-permeable gas not permeated by membrane separation of the first membrane separator, a second membrane separator provided at a downstream side of the first membrane separator and for further membrane-separating CO 2 from the first non-permeable gas, a second permeable gas discharge line for discharging second permeable gas permeated by membrane separation of the second membrane separator, a second permeable gas return line branched from a part of the second permeable gas discharge line and for returning the second permeable gas to a source gas side, and a CO 2 concentration meter are included.
1. A CO 2 separation device in gas, comprising:
a source gas introduction line configured to introduce source gas containing CO 2 ,
a first membrane separator connected to an end of the source gas introduction line and configured to membrane-separate CO 2 from the source gas;
a first permeable gas discharge line configured to discharge first permeable gas permeated by membrane separation of the first membrane separator to be collected as collected CO 2 ;
a first non-permeable gas discharge line configured to discharge first non-permeable gas not permeated by membrane separation of the first membrane separator;
a second membrane separator provided at a downstream side of the first membrane separator and configured to membrane-separate CO 2 from first non-permeable gas;
a second permeable gas discharge line configured to discharge second permeable gas permeated by membrane separation of the second membrane separator to be collected as collected CO 2 ;
a first permeable gas branch line branched from a part of the first permeable gas discharge line and configured to return the first permeable gas to the source gas;
a return line of second permeable gas branched from a part of the second permeable gas discharge line and configured to return the second permeable gas to a source gas side or a first non-permeable gas side; and
a CO 2 concentration meter provided in the first permeable gas discharge line and configured to measure CO 2 concentration in the first permeable gas; wherein
the second permeable gas and a part of the first permeable gas is recycled to the source gas side in the case where the CO 2 concentration in the first permeable gas is 90 mol % or less.
2. The CO 2 separation device in gas according to claim 1 , further comprising a CO 2 concentration meter for measuring CO 2 concentration in the source gas or the first permeable gas or the second permeable gas.
3. The CO 2 separation device in gas according to claim 1 , further comprising:
a CO 2 concentration meter for measuring CO 2 concentration in the source gas; and
a third membrane separator for pre-processing provided at an upstream side of the first membrane separator and configured to separate CO 2 in the source gas in accordance with CO 2 concentration in the source gas to obtain source gas having CO 2 gas concentration of the predetermined concentration.
4. The CO 2 separation device in gas according to claim 1 , in which a compressor provided in the source gas introduction line and configured to compress the introduced source gas is provided at an upstream side of the first membrane separator.
5. The CO 2 separation device in gas according to claim 1 , further comprising:
CO 2 separation equipment for further separating CO 2 in the second non-permeable gas discharged from the part of the second non-permeable gas discharge line; and
a return line of CO 2 gas configured to return the CO 2 gas separated by the CO 2 separation equipment to the source gas or the first non-permeable gas.
6. The CO 2 separation device in gas according to claim 1 , further comprising a compressor in the second permeable gas discharge line at a location after the return line of second permeable gas for compressing the second permeable gas to be collected as CO 2 .
7. A CO 2 separation device in gas, comprising:
a source gas introduction line configured to introduce source gas containing CO 2 ,
a first membrane separator connected to an end of the source gas introduction line and configured to membrane-separate CO 2 from the source gas;
a first permeable gas discharge line configured to discharge first permeable gas permeated by membrane separation of the first membrane separator to be collected as collected CO 2 ;
a first non-permeable gas discharge line configured to discharge first non-permeable gas not permeated by membrane separation of the first membrane separator;
a second membrane separator provided at a downstream side of the first membrane separator and configured to membrane-separate CO 2 from first non-permeable gas;
a second permeable gas discharge line configured to discharge second permeable gas permeated by membrane separation of the second membrane separator to be collected as collected CO 2 ;
a return line of second permeable gas branched from a part of the second permeable gas discharge line and configured to return the second permeable gas to a source gas side or a first non-permeable gas side; and
a CO 2 concentration meter provided in the source gas introduction line and configured to measure CO 2 concentration in the source gas; wherein
the second permeable gas is recycled to the source gas side in the case where the CO 2 concentration in the source gas is 20 mol % or less.
8. The CO 2 separation device in gas according to claim 7 , further comprising a first permeable gas branch line branched from a part of the first permeable gas discharge line and configured to return the first permeable gas to the source gas.
9. The CO 2 separation device in gas according to claim 7 , further comprising a CO 2 concentration meter for measuring CO 2 concentration in the source gas or the first permeable gas or the second permeable gas.
10. The CO 2 separation device in gas according to claim 7 , further comprising:
a CO 2 concentration meter for measuring CO 2 concentration in the source gas; and
a third membrane separator for pre-processing provided at an upstream side of the first membrane separator and configured to separate CO 2 in the source gas in accordance with CO 2 concentration in the source gas to obtain source gas having CO 2 gas concentration of the predetermined concentration.
11. The CO 2 separation device in gas according to claim 7 , in which a compressor provided in the source gas introduction line and configured to compress the introduced source gas is provided at an upstream side of the first membrane separator.
12. The CO 2 separation device in gas according to claim 7 , further comprising:
CO 2 separation equipment for further separating CO 2 in the second non-permeable gas discharged from the part of the second non-permeable gas discharge line; and
a return line of CO 2 gas configured to return the CO 2 gas separated by the CO 2 separation equipment to the source gas or the first non-permeable gas.
13. A method of membrane separation in a CO 2 separation device in gas comprising:
serially providing membrane separators including separation membrane for selectively separating CO 2 from source gas containing CO 2 in two stages;
discharging first permeable gas permeated by membrane separation of the first membrane separator to be collected as collected CO 2 and second permeable gas permeated by membrane separation of the second membrane separator to be collected as collected CO 2 ,
obtaining CO 2 concentration in the source gas or the first permeable gas after membrane separation by the first membrane separator when first non-permeable gas not permeated by membrane separation of the first membrane separator in the first stage is membrane-separated by the second membrane separator in the second stage;
recycling the second permeable gas after membrane separation by the second membrane separator to a source gas side in the case where the obtained CO 2 concentration in the first permeable gas is 90 mol % or less, or the obtained CO 2 concentration in the source gas is 20 mol % or less; and
returning the first permeable gas after membrane separation by the first membrane separator to the source gas.
14. A method of membrane separation in a CO 2 separation device in gas comprising:
serially providing membrane separators including separation membrane for selectively separating CO 2 from source gas containing CO 2 in two stages;
discharging first permeable gas permeated by membrane separation of the first membrane separator to be collected as collected CO 2 and second permeable gas permeated by membrane separation of the second membrane separator to be collected as collected CO 2 ,
obtaining CO 2 concentration in the source gas or the first permeable gas after membrane separation by the first membrane separator when first non-permeable gas not permeated by membrane separation of the first membrane separator in the first stage is membrane-separated by the second membrane separator in the second stage;
recycling the second permeable gas after membrane separation by the second membrane separator to a source gas side in the case where the obtained CO 2 concentration in the first permeable gas is 90 mol % or less, or the obtained CO 2 concentration in the source gas is 20 mol % or less;
further separating CO 2 in second non-permeable gas from the second membrane separator by CO 2 separation equipment; and
returning the CO 2 gas separated by the CO 2 separation equipment to the source gas or the first non-permeable gas.
15. A method for controlling membrane separation in the CO 2 separation device in gas, comprising:
serially providing first and second membrane separators including separation membrane for selectively separating CO 2 from source gas containing CO 2 in two stages, and providing a third membrane separator for pre-processing in a bypass line that bypasses a source gas introduction line at an upstream of the first membrane separator;
obtaining CO 2 concentration in the source gas when first non-permeable gas not permeated by membrane separation of the first membrane separator in the first stage is membrane-separated by the second membrane separator in the second stage; and
membrane-separating CO 2 in the source gas by the third membrane separator for pre-processing, setting the CO 2 concentration of third non-permeable gas not permeated by the third membrane separator to 30 mol % or less and introducing the third non-permeable gas having the CO 2 concentration of 30 mol % or less to the first membrane separator to selectively separate CO 2 .