Explanation

deuterium is an isotope of hydrogen, also called heavy hydrogen, with the chemical symbol of D or 2H. deuterium gas is a colorless, odorless flammability gas at normal temperature, with an abundance of 0.015% on the earth. It contains very little common hydrogen, and most of it exists in seawater and common water in the form of heavy water D2O, namely deuterium oxide. deuterium is an isotope of hydrogen, consisting of a proton, a neutron and an electron. It was discovered in liquid hydrogen by H.C. Yuri and F.G. Brickvid in 1931. The mass concentration of deuterium in seawater is about 30 mg/L. deuterium gas is widely used in military, thermonuclear experiments and optical fiber manufacturing. The separation principle of deuterium gas can be divided into two categories: one is to directly use the mass isotope effect, and the movement difference of individual isotope molecules and ions with different masses in the gravity field and electric field; The other is to use the statistical characteristics of isotopes. The main preparation methods of deuterium include liquid hydrogen distillation, electrolytic heavy water method, palladium/alloy film or metal hydride method. Electrolytic heavy water method: the main compound of deuterium is heavy water (D2O). Gaseous deuterium can be decomposed into heavy water by sodium or red hot iron, or obtained by electrolysis of heavy water in the presence of sodium carbonate. heavy water electrolysis is the main method to produce deuterium. The principle of deuterium production by electrolysis of heavy water is identical to that of hydrogen generation production by water electrolysis. deuterium gas is generated on the cathode and oxygen is generated on the anode. However, it uses solid electrolyte sulfonic group to bind to polylctrafluorocthylone. The conductive medium is hydrated deuterium ion (D+? D2O), while the sulfonic group is immobile. Using ordinary water electrolysis device, deuterium oxide as elonrolyte (such as KOD, NaOD), or SPE (Solid polymer Elec trolyte) membrane electrolyzer to electrolyze heavy water, 99% deuterium gas can be obtained on the cathode, and after separation and purification, high-purity deuterium products can be obtained. This method has high technical content, can be large or small in scale, is easy to control, and is safe and reliable. Palladium membrane or metal hydride method: because the decomposition pressure of deuteride is higher than that of hydride, the absorption equilibrium pressure of hydrogen and deuterium by the same metal is different from the decomposition equilibrium pressure. This pressure difference characteristic and their difference in activation or conditioning energy can be used to separate hydrogen and deuterium, which is suitable for the separation and purification of deuterium containing gas and the recovery and utilization of Tokamak waste gas in nuclear power plants. liquid hydrogen rectification method: the content of deuterium in natural hydrogen is 0.0139%~0.0156%, the boiling point of D2 is 23.5K, H2 is 20.38K, and the boiling point of HD (hydrogen deuteride) is 22.13K. It is theoretically entirely possible to produce deuterium gas by distilling liquid hydrogen. During low-temperature distillation, the first concentration is HD, which must be converted into D2 through a catalyst. The equilibrium mixture of HD and H2 can only continue distillation and concentration. There are four main processes for low-temperature distillation and separation of hydrogen isotopes, namely four tower process, three tower process, two tower process, and two tower process with side line return feed balance device.

Classification