摘要:
A isotopic gas of high purity is obtained at low cost, wherein for example, in a case of separating 13CH4 from methane gas and obtaining 13CH4 of high purity, the enrichment of 13CH4, using the difference in adsorption of 12CH4 and 13CH4 onto an adsorbing material, is performed up to a certain concentration, and thereafter, 13CH4 is enriched by a separation method by distillation that uses the difference in boiling point.