The object of the present invention is to provide a stable isotope concentration method that reduces equipment cost and power without prolonging the start-up time and enables efficient concentration, and the present invention provides 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 in the vicinity of the bottom of a (n−1)th column to a position in the vicinity of the top of an nth column (1<n≤m), and the other of liquid and gas is returned from a position in the vicinity of the top of the nth column to a position in the vicinity of 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.

The object of the present invention is to provide a stable isotope concentration method that reduces equipment cost and power without prolonging the start-up time and enables efficient concentration, and the present invention provides 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 in the vicinity of the bottom of a (n−1)th column to a position in the vicinity of the top of an nth column (1<n≤m), and the other of liquid and gas is returned from a position in the vicinity of the top of the nth column to a position in the vicinity of 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.

Method and Apparatus for separating at least one CO isotope compound, especially isotope compound 13C16O, from natural CO, comprising: a rectification column system (110) comprising a plurality of rectification sections (112,114,116,118,120) arranged adjacent to one another in a chain-like manner, including an upper rectification section (112) and a plurality of lower rectification sections (114,116,118,120), each rectification section comprising a heating means (112a,114a,116a,118a,120a) to maintain evaporation of liquid present therein, provided that the heating means (112a) of the at least one of the plurality of rectification sections (112) is provided to comprise a heat pump cycle (112b).

Method and Apparatus for separating at least one CO isotope compound, especially isotope compound 13C16O, from natural CO, comprising: a rectification column system (110) comprising a plurality of rectification sections (112,114,116,118,120) arranged adjacent to one another in a chain-like manner, including an upper rectification section (112) and a plurality of lower rectification sections (114,116,118,120), each rectification section comprising a heating means (112a,114a,116a,118a,120a) to maintain evaporation of liquid present therein, provided that the heating means (112a) of the at least one of the plurality of rectification sections (112) is provided to comprise a heat pump cycle (112b).

Method and Apparatus for separating at least one CO isotope compound, especially isotope compound 13C16O, from natural CO, comprising: a rectification column system (110) comprising a plurality of rectification sections (112,114,116,118,120) arranged adjacent to one another in a chain-like manner, including an upper rectification section (112) and a plurality of lower rectification sections (114,116,118,120), each rectification section comprising a heating means (112a,114a,116a,118a,120a) to maintain evaporation of liquid present therein, provided that the heating means (112a) of the at least one of the plurality of rectification sections (112) is provided to comprise a heat pump cycle (112b).

Method and Apparatus for separating at least one CO isotope compound, especially isotope compound 13C16O, from natural CO, comprising: a rectification column system (110) comprising a plurality of rectification sections (112,114,116,118,120) arranged adjacent to one another in a chain-like manner, including an upper rectification section (112) and a plurality of lower rectification sections (114,116,118,120), each rectification section comprising a heating means (112a,114a,116a,118a,120a) to maintain evaporation of liquid present therein, provided that the heating means (112a) of the at least one of the plurality of rectification sections (112) is provided to comprise a heat pump cycle (112b).

An object of the present invention is to provide a carbon stable isotope enrichment method that does not require safety measures against combustibility and toxicity and that enables high-concentration .sup.13C enrichment without isotope scrambling, and the present invention provides a carbon stable isotope enrichment method including a distillation step for enriching carbon tetrafluoride stable isotope molecules containing .sup.13C by distilling raw material carbon tetrafluoride containing multiple types of carbon tetrafluoride stable isotope molecules in a distillation column group in which multiple distillation columns are cascaded.

An object of the present invention is to provide a carbon stable isotope enrichment method that does not require safety measures against combustibility and toxicity and that enables high-concentration .sup.13C enrichment without isotope scrambling, and the present invention provides a carbon stable isotope enrichment method including a distillation step for enriching carbon tetrafluoride stable isotope molecules containing .sup.13C by distilling raw material carbon tetrafluoride containing multiple types of carbon tetrafluoride stable isotope molecules in a distillation column group in which multiple distillation columns are cascaded.

The present invention relates to the field of distillation of isotopes obtained by distillation columns. An object of the present invention is to describe an innovative distillation column which provides significant improvements to the prior art. In particular, the distillation column will be a modular innovatively conceived column having any needed height.

The present invention relates to the field of distillation of isotopes obtained by distillation columns. An object of the present invention is to describe an innovative distillation column which provides significant improvements to the prior art. In particular, the distillation column will be a modular innovatively conceived column having any needed height.