US 12,151,208 B2
Stable isotope concentration method
Takashi Kambe, Tokyo (JP); Takehiro Igarashi, Tokyo (JP); and Hitoshi Kihara, Tokyo (JP)
Assigned to TAIYO NIPPON SANSO CORPORATION, Tokyo (JP)
Appl. No. 17/914,971
Filed by TAIYO NIPPON SANSO CORPORATION, Tokyo (JP)
PCT Filed Mar. 8, 2021, PCT No. PCT/JP2021/008972
§ 371(c)(1), (2) Date Sep. 27, 2022,
PCT Pub. No. WO2021/199934, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-062432 (JP), filed on Mar. 31, 2020.
Prior Publication US 2023/0104429 A1, Apr. 6, 2023
Int. Cl. B01D 59/04 (2006.01); F25J 3/08 (2006.01)
CPC B01D 59/04 (2013.01) [F25J 3/08 (2013.01); F25J 2215/50 (2013.01); F25J 2220/90 (2013.01)] 2 Claims
OG exemplary drawing
 
1. A stable isotope concentration method using multiple cascaded distillation columns (1st column to mth column; m is an integer of 2 or more),
wherein the method includes a step in which one of gas and liquid is supplied from a position at the bottom of a (n−1) th column to a position at the top of an nth column (1<n=m), and when gas is supplied from the (n−1)th column to the nth column, liquid is returned, and when liquid is supplied from the (n−1)th column to the nth column, gas is returned from a position at the top of the nth column to a position at the bottom of the (n−1)th column; and
wherein in each distillation column, when a flow rate of an ascending gas in the column is a first flow rate and a flow rate of the gas or the liquid supplied from a previous column or a next column is a second flow rate, the second flow rate is 4% by volume or more with respect to the first flow rate.