Method for separating carbon isotopes using electromigration

Abstract

The present invention relates to an apparatus for separating carbon isotopes and a method for separating carbon isotopes using same. Specifically, the apparatus for separating carbon isotopes according to an aspect of the present invention comprises: a pocket part which is composed of a magnetic metal to store a carbon mixture in the center portion thereof; an electrode connection part at both ends; and a graphite precipitation part between the pocket part and the electrode connection part, wherein carbon isotopes can be efficiently separated and concentrated through electromigration.

Description

Carbon isotope separation method using electromigration

[0001] The present invention relates to a method for separating and concentrating carbon isotopes using electromigration.

[0002] Isotope separation technology is a technology for separating specific isotopes from a mixture of isotopes of the same element with different atomic weights.

[0003] Meanwhile, carbon is carbon-12, which has a natural composition ratio of 98.89%. 12 C) and 1.1% carbon-13( 13 C) There are two types of stable isotopes, and each isotope is extremely useful in various industrial fields, making them a crucial source of isotope separation and enrichment. However, current techniques for separating carbon isotopes require expensive equipment and specialized skills, use materials that are harmful to the environment and human health, and have low separation efficiency.

[0004] One aspect of the present invention provides a separation device capable of efficiently separating and concentrating carbon isotopes and a method for separating carbon isotopes using the same.

[0005] One aspect of the present invention provides a carbon isotope separation device comprising: a pocket portion storing a carbon mixture in a central portion; electrode connection portions at both ends; and a graphite precipitation portion between the pocket portion and the electrode connection portion; wherein the carbon isotope separation device is made of a magnetic metal.

[0006] The above magnetic metal may be nickel or cobalt.

[0007] The above carbon isotope separation device may further include a joule heating device connected to the electrode connection.

[0008] Another aspect of the present invention comprises the steps of: connecting the electrode connection part of the carbon isotope separation device to the electrode of the line heating device; connecting the pocket part of the carbon isotope separation device to the electrode of the line heating device; 12 C and 13 A method for separating carbon isotopes is provided, comprising the steps of: introducing a carbon mixture containing C and heating the mixture to melt the carbon mixture; and precipitating graphite through electromigration.

[0009] The above precipitated graphite 12 C content is the carbon content of the mixture. 12 It may be more than 16at% of the C content.

[0010] The above-mentioned line heating may form a temperature gradient that decreases in the direction of both ends in the pocket portion.

[0011] The temperature of the above pocket portion may be 1300°C to 1400°C, and the temperature of the graphite precipitation portion may be 800°C to 1,200°C.

[0012] The above electromigration may be performed for 20 to 60 hours.

[0013] The carbon isotope separation method using electromigration of the present invention produces well-aligned graphite while simultaneously separating and concentrating carbon isotopes economically and environmentally friendly. Specifically, the carbon isotope separation method according to one embodiment is environmentally friendly because it does not use materials harmful to the human body or the environment, and it also has the advantages of a simple process and high energy efficiency, making it expected to be advantageous for practical industrial applications.

[0014] Figure 1 is a photograph of a carbon isotope separation device according to one embodiment.

[0015] FIG. 2 is a photograph of a carbon isotope separation device connected to a string heating device according to one embodiment.

[0016] FIG. 3 is a photograph of a carbon isotope separation device after performing electromigration according to one embodiment.

[0017] Figure 4 is a temperature gradient graph for regions a to e shown in Figure 3.

[0018] Figure 5 is a Raman spectrum for the regions a to e shown in Figure 3.

[0019] FIG. 6 is an image of the boundary between a precipitated graphite region and a magnetic metal (nickel) region observed with a scanning electron microscope after performing electromigration according to one embodiment.

[0020] Figure 7 is a carbon mixture source. 13 C content (at%) and graphite precipitation after electromigration in Examples 1 to 10 13 This is a graph showing the C content.

[0021] Unless otherwise defined herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0022] As used herein, the singular forms may be intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0023] Throughout this specification, the terms "comprises," "includes," "contains," or "has" a component, unless specifically stated to the contrary, do not exclude other components, but rather may include other components, and do not exclude additional unrecited elements, materials, or processes.

[0024] The numerical ranges used herein include the lower and upper limits and all values ​​within that range, increments logically derived from the shape and width of the defined range, all doubly defined values, and all possible combinations of the upper and lower limits of numerical ranges defined in different shapes. Unless otherwise specified herein, values ​​outside the defined range that may arise due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0025] Unless otherwise specified herein, “about” may be considered a value within 30%, 25%, 20%, 15%, 10% or 5% of the stated value.

[0026] In this specification, “joule heating” means a process in which heat is generated due to the flow of electric current through a conductor.

[0027] In this specification, “electromigration” refers to a phenomenon in which atoms in a metal move along the current when a current is applied to the metal.

[0028] Below, the present disclosure will be described in detail. However, this is merely exemplary and the present disclosure is not limited to the specific embodiments described as examples.

[0029] One aspect of the present invention provides a device capable of separating and concentrating carbon isotopes using electromigration, and a method for separating carbon isotopes using the same.

[0030] A carbon isotope separation device according to one embodiment (Fig. 1) may be made of a magnetic metal and include a pocket portion storing a carbon mixture in the center; electrode connection portions at both ends; and a graphite precipitation portion between the pocket portion and the electrode connection portion.

[0031] The above magnetic metal can be used without limitation as long as it is a magnetic metal with high solubility in carbon, and non-limiting examples thereof include nickel or cobalt.

[0032] The carbon isotope separation device according to one embodiment may further include a joule heating device connected to the electrode connection portion (Fig. 2).

[0033] Another aspect of the present invention provides a method for separating carbon isotopes using the above-described carbon isotope separation device.

[0034] A method for separating carbon isotopes according to one aspect comprises the steps of: connecting an electrode connection part of the above-described carbon isotope separation device to an electrode of a line heating device; and connecting a pocket part of the carbon isotope separation device to the electrode of the line heating device. 12 C and 13 It may include a step of introducing a carbon mixture including C and heating the mixture to melt the carbon mixture; and a step of precipitating graphite through electromigration.

[0035] The above precipitated graphite 12 C content is the carbon content of the mixture. 12 It may be 1 at% or more, 2 at% or more, 5 at% or more, or 10 at% or more, or 16 at% or more, or 95 at% or less, or 92 at% or less, or 90 at% or less, relative to the C content. That is, according to the carbon isotope separation method according to one aspect, a relatively lighter isotope is separated by electromigration. 12 It can be seen that C diffuses faster through the metal and can be precipitated in concentrated amounts compared to the carbon mixture source, and by repeating the above separation method, pure 13 C and 12 It is expected that C can be separated.

[0036] According to a method for separating carbon isotopes according to one aspect, a temperature gradient that decreases in the direction of both ends from the pocket portion may be formed by the above-described Joule heating, and the graphite precipitation portion may mean a section where carbon atoms moving through electromigration are precipitated by the decreasing temperature gradient.

[0037] At this time, when performing string heating using direct current, graphite can be precipitated only in the graphite precipitation portion in the cathode direction based on the pocket portion, and when using alternating current, graphite can be precipitated in both graphite precipitation portions based on the pocket portion.

[0038] When performing the above electromigration, the temperature of the pocket portion may be a temperature range in which carbon can be dissolved, for example, 1,300°C to 1,400°C, or 1,300°C to 1,350°C, and the temperature of the graphite precipitation portion may be 800°C to 1,200°C, or 900°C to 1,200°C, or 900°C to 1,100°C.

[0039] The above electromigration may be performed for 20 to 60 hours, or 30 to 60 hours, or 40 to 60 hours, and may be performed under an argon atmosphere.

[0040] Hereinafter, the above-described implementation examples will be described in more detail through examples. However, the following examples are for illustrative purposes only and do not limit the scope of the rights.

[0041] The physical properties of the examples were measured as follows.

[0042] 1. Scanning Electron Microscope (SEM)

[0043] The graphite precipitation region was characterized using a scanning electron microscope (FEI Verios 460) under conditions of 10 kV electron accelerating voltage and 0.8 nA beam current.

[0044] 2. Raman spectrum

[0045] A confocal Raman microscope (Horiba LabRAM HR Evolution) was used in mapping mode with a 532 nm laser source, a x100 objective, 10% (~3 mW) laser power, one accumulation, and an acquisition time of 0.5 s, and the resulting spectra were plotted by analyzing them with OriginPro software.

[0046] [Example 1]

[0047] Nickel metal bulk (Shaanxi Super Metal Materials Co. Limited) with a purity of 99.9 wt% was processed into a carbon isotope separation device (Fig. 1). The carbon isotope separation device made of nickel was annealed in an argon:hydrogen = 1:3 atmosphere, and both ends were connected to electrode holders of a string heater (Fig. 2).

[0048] since, 12 C carbon powder (Alfa Aesar) and 13 A carbon mixture source containing C carbon powder (Cambridge Isotope Laboratories Inc.) in a 10 / 90 weight ratio was ball milled and then placed into the pocket of a carbon isotope separation device. Joule heating was then performed by applying direct current under an argon atmosphere, and electromigration was performed for 50 h at a pocket temperature of 1350°C (Fig. 3). The temperature was monitored using a pyrometer focused on the lower region of the pocket through the side window of the furnace.

[0049] A photograph of a carbon isotope separation device after performing electromigration is shown in FIG. 3, and the temperature gradient graph and Raman spectrum for regions a to e shown in FIG. 3 are shown in FIG. 4 and FIG. 5, respectively, and the scanning electron microscope measurement results for region c are shown in FIG. 6.

[0050] Referring to Fig. 4, it can be seen that a temperature gradient is formed in which the temperature decreases in the direction of both ends based on the pocket portion, and referring to Fig. 5, it can be seen that the G and 2D peaks, which are Raman spectrum peaks of graphite, are observed only in the c to d region. That is, it was confirmed that graphite was precipitated only in the temperature decreasing region (c to d) corresponding to the cathode direction based on the pocket portion, and it can be seen that carbon diffuses by electromigration and graphite is precipitated in the region where the temperature decreases.

[0051] [Examples 2 to 5]

[0052] Isotope ratios of carbon mixture sources ( 12 C / 13 C) was performed in the same manner as in Example 1, except that the weight ratio was changed from 10 / 90 to 30 / 70, 50 / 50, 70 / 30, and 90 / 10.

[0053] [Example 6]

[0054] The same procedure as in Example 1 was followed, except that cobalt metal bulk (Shaanxi Super Metal Materials Co. Limited) with a purity of 99.95 wt% was used instead of nickel metal as the material for the carbon isotope separation device.

[0055] [Examples 7 to 10]

[0056] Isotope ratios of carbon mixture sources ( 12 C / 13 C) was performed in the same manner as in Example 6, except that the weight ratio was changed from 10 / 90 to 30 / 70, 50 / 50, 70 / 30, and 90 / 10.

[0057] The weight ratios of 10 / 90, 30 / 70, 50 / 50, 70 / 30, and 90 / 10 used in the above examples 12 C / 13By measuring IRMS (Isotope Ratio Mass Spectrometry) for C carbon mixture sources, 13 The results of calculating the C content (at%) are shown in Table 1 below. In addition, through the Raman spectrum results for the graphite precipitates after performing electromigration in Examples 1 to 10, 13 Calculating the C content (at%) (Nano Lett. 2009, 9, 12, 4268-4272) and the carbon mixture source 13 It is shown in Figure 7 in comparison with the C content (at%).

[0058] Carbon mixture source ( 12 C / 13 C)IRMS 12 C (at%) 13 C(at%)10 / 9010.7089.3030 / 7032.8367.1750 / 5050.9549.0570 / 3071.8028.2090 / 1090.209.80

[0059] Referring to Fig. 7, the graphite contained in the graphite precipitated through electromigration 13 It can be seen that the C content decreases compared to the initial carbon mixture source, i.e., the relatively lighter isotope is lost through electromigration. 12 It was confirmed that C can diffuse faster through the metal and be precipitated in concentrated amounts compared to the carbon mixture source, and this experiment was repeated to obtain pure 13 C and 12 It is expected that C can be separated.

[0060] As described above, the present invention has been described by limited embodiments, but these are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains can make various modifications and variations based on this description.

[0061] Therefore, the idea of ​​the present invention should not be limited to the described embodiments, and all things that are equivalent or equivalent to the following claims as well as the claims are considered to fall within the scope of the idea of ​​the present invention.

Claims

1. A carbon isotope separation device comprising a pocket portion storing a carbon mixture in a central portion; electrode connection portions at both ends; and a graphite precipitation portion between the pocket portion and the electrode connection portion; A carbon isotope separation device, wherein the above carbon isotope separation device is made of a magnetic metal.

2. In paragraph 1, A carbon isotope separation device, wherein the magnetic metal is nickel or cobalt.

3. In paragraph 1, A carbon isotope separation device, wherein the carbon isotope separation device further includes a joule heating device connected to an electrode connection portion.

4. A step of connecting the electrode connection part of the carbon isotope separation device according to paragraph 1 to the electrode of the line heating device; In the pocket part of the carbon isotope separation device 12 C and 13 A method for separating carbon isotopes, comprising the steps of: introducing a carbon mixture containing C and heating the mixture to melt the carbon mixture; and precipitating graphite through electromigration.

5. In paragraph 4, The above precipitated graphite 12 C content is the carbon content of the mixture. 12 A method for separating carbon isotopes having a C content of 16 at% or more.

6. In paragraph 4, A method for separating carbon isotopes, wherein a temperature gradient is formed in the pocket section by heating the above-mentioned string, thereby decreasing in the direction of both ends.

7. In paragraph 6, A method for separating carbon isotopes, wherein the temperature of the pocket portion is 1300°C to 1400°C, and the temperature of the graphite precipitation portion is 800°C to 1,200°C.

8. In paragraph 4, A method for separating carbon isotopes, wherein the above electromigration is performed for 20 to 60 hours.

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