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CN-121972105-A - Method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis

CN121972105ACN 121972105 ACN121972105 ACN 121972105ACN-121972105-A

Abstract

The invention belongs to the technical field of isotope recovery and separation, and discloses a method for recovering high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis. The invention selects the proper concentration of the dilute sulfuric acid to maintain the hydrolysis rate of the carbon 13 urea, and prevents the sulfate radical and the urea from forming an adduct by controlling the concentration of the dilute sulfuric acid, thereby increasing 13 CO 2 release efficiency, controlling the reaction rate and avoiding side reactions. The invention also establishes a set of reaction device for carrying out acidic constant-temperature hydrolysis recovery 13 CO 2 of the carbon 13 urea under reduced pressure, obviously increases the gas-liquid phase contact area and the residence time by arranging the rectifying column, realizes visual water removal and low temperature by a water removal column and a condensing tube, solves the problems of pollution of external CO 2 , high impurity air content and higher water content, and ensures 13 CO 2 to realize higher abundance recovery.

Inventors

  • XU PENGFEI
  • LIU ZHENXING
  • YANG DIAN
  • WU XI
  • HE HONGYU
  • ZHAO DONGSHENG
  • YU HAIBO

Assignees

  • 安徽中核桐源科技有限公司

Dates

Publication Date
20260505
Application Date
20251226

Claims (7)

  1. 1. A method for recovering high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis, which is characterized by comprising the following steps: (1) Assembling a reaction device; The reaction device comprises a reaction container, a rectifying column, an intermediate container 1, a dewatering column, an intermediate container 2, a condensing tube, a steel bottle and a vacuum pump which are sequentially connected through pipelines; the reaction device also comprises a magnetic stirrer and a liquid nitrogen container, wherein the reaction container is arranged on the magnetic stirrer; (2) Placing carbon 13 urea and sulfuric acid solution in a reaction container, vacuumizing the reaction device through a vacuum pump, adding liquid nitrogen into a liquid nitrogen container, and pre-cooling a steel bottle for standby; (3) And (3) heating and stirring by a magnetic stirrer, heating to react, rectifying products generated in the reaction process by a rectifying column, dehydrating by a dehydrating column, condensing by a condensing pipe, and finally collecting the carbon 13 carbon dioxide which is obtained by dry icing in a steel bottle to finish the recovery of the high-abundance carbon 13 carbon dioxide from the carbon 13 urea based on acidic constant-temperature hydrolysis.
  2. 2. The method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis according to claim 1, wherein the water removal column is filled with cobalt-free allochroic silica gel with the particle size of 3-5 mm.
  3. 3. The method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis according to claim 2, wherein the circulating cooling medium of the condensing tube is absolute ethyl alcohol, and the temperature of the circulating cooling medium of the condensing tube is-10 ℃.
  4. 4. The method for recovering high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis according to claim 3, wherein the pressure in the reaction device after vacuum pumping is less than or equal to 30mTorr.
  5. 5. The method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis according to claim 4, wherein the mass fraction of the sulfuric acid solution is 10-60%.
  6. 6. The method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis according to claim 5, wherein the molar ratio of the carbon 13 urea to sulfuric acid in the sulfuric acid solution is 1-6:1.
  7. 7. The method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis according to claim 6, wherein the reaction temperature is 80-90 ℃, and the reaction time is 1-6 h.

Description

Method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis Technical Field The invention relates to the technical field of isotope recovery and separation, in particular to a method for recovering high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis. Background According to the latest data, the annual yield of 13 C urea reaches 4000 kg, wherein about 8-10% of the urea becomes a defective product due to the fact that the abundance is not up to standard (85-95%), but the current treatment mode of the defective product mainly has the following three types of defects: (1) The incineration method can lead to the complete loss of 13 C resources, and the treatment cost per ton is up to 2 ten thousand yuan; (2) The traditional acidolysis method adopts 98% concentrated sulfuric acid to directly decompose, and can generate 13CO2, but the reaction releases heat severely to cause the local temperature to exceed 200 ℃, urea condensation is initiated to generate biuret (the side reaction rate is more than 8%), acid mist corrodes equipment (the annual corrosion rate of 316L stainless steel is more than 0.8 mm), the cost is higher, the uncontrollable risk of the reaction is larger, and the purification is difficult; (3) The pyrolysis method is carried out at a high temperature of more than 300 ℃, so that the energy consumption is high and the cost is high. How to solve the obvious defects of the existing 13 C urea reject treatment mode is a problem which needs to be solved in the isotope resource recovery field. Disclosure of Invention The invention aims to provide a method for recovering high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis, which solves the problems of the existing 13 C urea reject processing mode. In order to achieve the above object, the present invention provides the following technical solutions: the invention provides a method for recycling high-abundance carbon 13 carbon dioxide from carbon 13 urea based on acidic constant-temperature hydrolysis, which comprises the following steps: (1) Assembling a reaction device; The reaction device comprises a reaction container, a rectifying column, an intermediate container 1, a dewatering column, an intermediate container 2, a condensing tube, a steel bottle and a vacuum pump which are sequentially connected through pipelines; the reaction device also comprises a magnetic stirrer and a liquid nitrogen container, wherein the reaction container is arranged on the magnetic stirrer; (2) Placing carbon 13 urea and sulfuric acid solution in a reaction container, vacuumizing the reaction device through a vacuum pump, adding liquid nitrogen into a liquid nitrogen container, and pre-cooling a steel bottle for standby; (3) And (3) heating and stirring by a magnetic stirrer, heating to react, rectifying products generated in the reaction process by a rectifying column, dehydrating by a dehydrating column, condensing by a condensing pipe, and finally collecting the carbon 13 carbon dioxide which is obtained by dry icing in a steel bottle to finish the recovery of the high-abundance carbon 13 carbon dioxide from the carbon 13 urea based on acidic constant-temperature hydrolysis. Preferably, the water removal column is filled with cobalt-free allochroic silica gel with the particle size of 3-5 mm. Preferably, the circulating cooling medium of the condensing pipe is absolute ethyl alcohol, and the temperature of the circulating cooling medium of the condensing pipe is-10 ℃. Preferably, the pressure in the reaction device after vacuumizing is less than or equal to 30mTorr. Preferably, the mass fraction of the sulfuric acid solution is 10-60%. Preferably, the molar ratio of the carbon 13 urea to the sulfuric acid in the sulfuric acid solution is 1-6:1. Preferably, the reaction temperature is 80-90 ℃, and the reaction time is 1-6 hours. Compared with the prior art, the invention has the following beneficial effects: (1) The invention selects the proper concentration of the dilute sulfuric acid to maintain the hydrolysis rate of the carbon 13 urea, and prevents the sulfate radical and the urea from forming adducts (such as [ CO (NH 2)2·H2SO4 ]) by controlling the concentration of the dilute sulfuric acid, thereby increasing the 13CO2 release efficiency, controlling the reaction rate and avoiding side reactions. (2) The invention builds a set of reaction device for recovering 13CO2 of carbon 13 urea through acidic constant-temperature hydrolysis under reduced pressure, obviously increases the gas-liquid contact area and the residence time by arranging the rectifying column, realizes visual water removal and low temperature by removing water columns and condensing pipes, solves the problems of pollution of external CO 2, high impurity air content and higher water content, and ensures 13CO2 to realize hi