KR20160098662A - Reduction method of gas using couette-taylor reactor - Google Patents

Abstract

The present invention relates to a gas reduction method using a Couette-Taylor reactor comprising the steps of: supplying an electrolyte and gas to the Couette-Taylor reactor including an external cylinder and an internal cylinder; mixing the electrolyte and the gas by rotating the internal cylinder of the Couette-Taylor reactor; and electrolyzing a mixture of the electrolyte and the gas by applying constant voltage or constant current to the external cylinder and the internal cylinder.

Description

Reduction method of gas using couette-taylor reactor [

The present invention relates to a process for reducing a gas using a Quatt-Taylor reactor.

Recently, global cooperation for greenhouse gas reduction, which is the main cause of global warming, and greenhouse gas regulation and climate change response policies in each country are being actively implemented. The Kyoto Protocol, which was formally enacted in February 2005, includes the six major greenhouse gases: CO ₂ , CH ₄ (methane), N ₂ O (nitrous oxide), HFC (Hydro Fluor Carbon), PFC Carbon: Perfluorocarbons), SF ₆ (sulfur hexafluoride), and imposed greenhouse gas reduction obligations around the world.

Of the six greenhouse gases, N ₂ O not only has a global warming index that is 310 times that of CO ₂ , but also contributes to the destruction of the ozone layer. N ₂ O is mainly produced industrially in the fluidized bed combustion process, the nitric acid production process, the adipic acid production process and the caprolactam production process, and is expected to increase by 0.5 to 0.9 ppb annually according to the biological nitrogen circulation. CH ₄ , HFCs, PFCs and SF ₆ can be recycled after the collection and recycling process for greenhouse gas reduction and treatment. On the other hand, N ₂ O is a chemically stable material compared to other nitrogen oxides, and material conversion using an additional process is required after the collection and recovery process, such as CO ₂ treatment.

Currently, N ₂ O pyrolysis, high temperature catalytic decomposition, mid-temperature catalytic decomposition and selective catalytic reduction (SCR) technologies have been developed to reduce N ₂ O occurring in various industrial fields, but most of them are required to be high energy and high cost . Such techniques are suitable for use as an additional source of heat generated during the manufacturing process in industry, but are unsuitable for decomposing N ₂ O generated at room temperature from livestock manure, anesthetic gas, and the like. Therefore, a technique capable of decomposing N ₂ O at room temperature is indispensable.

Electrolysis technology using electrochemical reaction is a typical technique for decomposing N ₂ O at normal temperature conditions. N ₂ O reduction with the electrochemical reaction using the electric energy of the external in such a way as to reduce the N ₂ O adsorbed to the electrode with N _2, the electrode and the electrolyte, the interface between the N ₂ O dissolved in the electrolyte relevant to the reaction And the potential applied to the electrode also has a great influence. So much for N ₂ O in research efficiency selective development of the electrode material (catalyst), and an electrolyte that can be reduced to, but focuses on the development of the optimal electrode-based control methods, such as setting the potential, substantially N ₂ O electrolysis There is no such process system.

As a prior art related thereto, there is a contact decomposition method of N ₂ O disclosed in Korean Patent Laid-Open Publication No. 10-1993-0009637 (published on June 21, 1993).

Accordingly, it is an object of the present invention to provide a method for reducing a greenhouse gas, which is a main cause of global warming, using a Kuett-Taylor reactor.

The problems to be solved by the present invention are not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a method for manufacturing a quartz-Taylor reactor including: supplying an electrolyte and a gas to a Kuett-Taylor reactor including an outer cylinder and an inner cylinder; Rotating the inner cylinder of the Kuett-Taylor reactor to uniformly mix the electrolyte and the gas; And applying a constant voltage or a constant current to the outer cylinder and the inner cylinder to electrolyze the mixture of the electrolyte and the gas. The present invention also provides a method of reducing gas using the CuTe-Taylor reactor.

The electrolyte is potassium sulfate (K ₂ SO _4), sodium hydroxide (NaOH), sodium chloride (NaCl), potassium hydroxide (KOH), potassium chloride (KCl), potassium nitrate (KNO _3), potassium carbonate (KHCO _3), first At least one selected from the group consisting of sodium phosphate (NaH ₂ PO ₄ ), sodium diphosphate (Na ₂ HPO ₄ ) and sodium ascorbate can be used.

And the concentration of the electrolyte is 0.01 to 0.5 M.

The gas is carbon monoxide (CO), carbon dioxide (CO _2), nitrogen monoxide (NO), nitrogen dioxide (NO _2), nitrous oxide (N ₂ O), diantimony nitrogen (N ₂ O _3), dinitrogen tetroxide (N ₂ O ₄ ), dinitrogen monoxide (N ₂ O ₅ ), sulfur dioxide (SO ₂ ) and sulfur trioxide (SO ₃ ) can be used.

The electrolyte and the gas are supplied at a rate of 1 to 500 ml / min.

And the inner cylinder is rotated at 20 to 10,000 rpm.

At this time, if the outer cylinder of the Kuett-Taylor reactor is an operating electrode, the inner cylinder is a counter electrode, and if the outer cylinder is a counter electrode, the inner cylinder is an operating electrode.

The outer and inner cylinders of the Kuett-Taylor reactor are made of titanium (Ti), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu) Au), indium (In), tin (Sn), and lead (Pb) is wrapped around the outside of stainless steel (SUS).

The outer cylinder and the inner cylinder of the Kuett-Taylor reactor are made of stainless steel (Ti), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt) And at least one selected from the group consisting of gold (Ag), gold (Au), indium (In), tin (Sn) and lead (Pb).

And the constant voltage is applied in a range of -5.0 to 5.0V.

And the constant current is applied in a range of 0.1 mA to 5.0 A.

Further, after the electrolysis, the undegraded gas is re-supplied to the Kuett-Taylor reactor to electrolyze.

According to the present invention, not only is it possible to quickly and uniformly mix an electrolyte and a gas using a Kuett-Taylor reactor to increase the solubility of the gas dissolved in the electrolyte, but also to use the outer cylinder and inner cylinder of the Kuett- Thereby allowing the gas to be electrolyzed in the reactor.

In addition, mixing of the gas and the electrolyte and decomposition of the gas can be performed at the same time, thereby shortening the process time and enabling the gas to be electrolyzed with high efficiency.

FIG. 1 is a flowchart showing a method of reducing a gas using a Kuett-Taylor reactor according to the present invention.
2 is a schematic diagram showing a Kuett-Taylor reactor used in a reducing method of a gas using a Kuett-Taylor reactor according to the present invention.
FIG. 3 is a graph showing changes in cyclic voltammetry (CV) according to the concentration of the gas dissolved in the electrolyte in the gas reduction method using the Kuett-Taylor reactor according to the present invention.
4 is a graph showing the calibration curve of I _p at the N ₂ O concentration obtained from FIG. 3 and the voltage near -0.5 V (vs. SCE).
FIG. 5 is a graph showing the solubility of a gas depending on the use of a Kuett-Taylor reactor in a reducing method using a Kuett-Taylor reactor according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving it will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

The present invention provides a method for producing a quat-Taylor reactor comprising: supplying an electrolyte and a gas to a Kuett-Taylor reactor comprising an outer cylinder and an inner cylinder;

Rotating the inner cylinder of the Kuett-Taylor reactor to uniformly mix the electrolyte and the gas; And

And applying a constant voltage or a constant current to the outer cylinder and the inner cylinder to electrolyze the mixture of the electrolyte and the gas. The present invention also provides a method of reducing gas using the CuTe-Taylor reactor.

The method of reducing the gas using the CuTe-Taylor reactor according to the present invention is a method of rapidly and uniformly mixing an electrolyte and a gas using a CuTe-Taylor reactor to increase the solubility of the gas dissolved in the electrolyte, The gas can be electrolyzed in the reactor using the outer cylinder and the inner cylinder of the reactor as electrodes. In addition, mixing of the gas and the electrolyte and decomposition of the gas can be performed at the same time, thereby shortening the process time and enabling the gas to be electrolyzed with high efficiency.

FIG. 1 is a flowchart showing a method of reducing a gas using a Kuett-Taylor reactor according to the present invention. Hereinafter, the present invention will be described in detail with reference to Fig.

The method of reducing a gas using a Kuett-Taylor reactor according to the present invention includes the step (S10) of supplying an electrolyte and a gas to a Kuett-Taylor reactor including an outer cylinder and an inner cylinder.

In the method of reducing the gas using the Kuett-Taylor reactor according to the present invention, it is preferable to use a substance that does not cause a side reaction while assisting current flow in the electrolyte during electrolysis, specifically potassium sulfate (K ₂ SO ₄ ), Sodium hydroxide (NaOH), sodium chloride (NaCl), potassium hydroxide (KOH), potassium chloride (KCl), potassium nitrate (KNO ₃ ), potassium carbonate (KHCO ₃ ), sodium monophosphate (NaH ₂ PO ₄ ) Sodium diphosphate (Na ₂ HPO ₄ ) and sodium ascorbate (Na-ascorbate) can be used.

The concentration, pH and temperature of the electrolyte may vary depending on the kind of the electrolyte and the electrolysis conditions. In the present invention, the concentration of the electrolyte is preferably 0.01 to 0.5 M. When the concentration of the electrolyte is less than 0.01 M, there is a problem that the electrolytic efficiency is lowered due to the high resistance of the electrolyte. When the concentration exceeds 0.5 M, there is a problem that a large amount of gas can not be saturated.

Also, the pH may be 1 to 13, and the internal temperature of the reactor is preferably 0 to 40 ° C. When the temperature of the reactor is lower than 0 ° C, there is a problem that the electrolyte solidifies and flow can not be formed. When the temperature exceeds 40 ° C, there is a problem that a large amount of gas can not be saturated.

A material in which the gas was reduced by the electrolytic character, carbon monoxide (CO), carbon dioxide (CO _2), nitrogen monoxide (NO), nitrogen dioxide (NO _2), nitrous oxide (N ₂ O), diantimony nitrogen (N ₂ O ₃ ), dinitrogen tetroxide (N ₂ O ₄ ), dinitrogen monoxide (N ₂ O ₅ ), sulfur dioxide (SO ₂ ) and sulfur trioxide (SO ₃ ) can be used.

At this time, it is preferable that the electrolyte and the gas are supplied at a rate of 1 to 500 ml / min. When the feed rate exceeds 500 ml / min, there is a problem that the flow of the quat-Taylor vortex is not formed due to the rapid flow in the axial direction.

Next, the method for reducing gas using the Kuett-Taylor reactor according to the present invention includes rotating the inner cylinder of the Kuett-Taylor reactor to uniformly mix the electrolyte and the gas (S20).

The inner cylinder is preferably rotated at 20 to 10,000 rpm. When the rotation is less than 20 rpm, there is a problem that a Kuett-Taylor vortex flow is not formed, and when the rotation is more than 10,000 rpm, there is a problem that the electrolysis efficiency is lowered.

In the method of reducing gas using the Kuett-Taylor reactor according to the present invention, when the inner cylinder is rotated, the electrolyte flows in the rotating direction. The centrifugal force and the Coriolis force cause the fluids present in the inner cylinder to flow toward the outer cylindrical direction And becomes more unstable as the rotational speed increases, so that a vortex that rotates in opposite directions regularly along the axial direction can be formed to uniformly mix the gas in the electrolyte and increase the solubility of the gas.

The method for reducing gas using the Kuett-Taylor reactor according to the present invention includes a step (S30) of electrolyzing a mixture of the electrolyte and the gas by applying a constant voltage or a constant current to the outer cylinder and the inner cylinder.

At this time, if the outer cylinder of the Kuett-Taylor reactor is the working electrode, the inner cylinder is the counter electrode, and if the outer cylinder is the counter electrode, the inner cylinder may be the working electrode.

The outer cylinder and the inner cylinder of the CuTe-Taylor reactor may be made of titanium, iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu) The foil comprising at least one selected from the group consisting of gold (Au), indium (In), tin (Sn) and lead (Pb) may be in the form of enveloping the outside of stainless steel (SUS) - The outer cylinder and the inner cylinder of the Taylor reactor are made of titanium (Ti), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu) , Gold (Au), indium (In), tin (Sn) and lead (Pb).

The constant voltage is preferably applied at -5.0 to 5.0V. When the above-mentioned constant voltage is lower than -5.0 V, there is a problem that not only the gas but also the electrolyte is reduced, and when it exceeds 5.0 V, there is a problem that the electrolyte is oxidized.

The constant current is preferably applied in a range of 0.1 mA to 5.0 A. When the constant current is less than 0.1 mA, there is a problem that the electrolysis rate is slow. When the constant current is more than 5.0 A, the electrolysis efficiency is lowered.

In addition, it is possible to perform electrolysis by applying a pulse. When a pulse is applied, the voltage or current can be changed and electrolyzed according to the electrolysis time within the range of applying the constant voltage to the constant current.

The method of reducing a gas using the Kuett-Taylor reactor according to the present invention may further include supplying the undegraded gas after the electrolysis to the Kuett-Taylor reactor to electrolyze it.

In the method of reducing the gas using the Kuett-Taylor reactor according to the present invention, the gas which has not been decomposed after the electrolysis is recovered at the outlet, and the gas is put into the Cu-Taylor reactor and electrolyzed.

FIG. 2 is a schematic view showing a Kuett-Taylor reactor in a reducing method of a gas using a Kuett-Taylor reactor according to the present invention. 2, the Kuett-Taylor reactor 100 according to the present invention includes an outer cylinder 120, an inner cylinder 130, and a drive motor 110 for rotating the inner cylinder 130, An inner cylinder 130 is provided in the outer cylinder 120. An inlet 140 is provided at one side of the cylindrical external cylinder 120 in which the interior is hollow and a terminal outlet 150 is provided at an opposite side of the inlet 140. A plurality Side discharge ports 151, 152, 153, and 154 are provided. Valves are provided in each of the injection port 140, the terminal discharge port 150 and the plurality of side discharge ports 151, 152, 153 and 154 to control and interrupt the injection and discharge of the electrolyte and the gas.

The above-described Kuett-Taylor reactor can be used to reduce the gas. Specifically, when the electrolyte and the gas are supplied through the inlet 140 of the Kuett-Taylor reactor 100 including the outer cylinder 120 and the inner cylinder 130, the electrolyte and the gas are supplied to the outer cylinder 120, And the inner cylinder 130. The inner cylinder 130 of the KuT-Taylor reactor 100 is rotated to generate a flow. When the angular velocity of the inner cylinder 130 is slow, a laminar quet flow is generated. On the other hand, as the angular velocity increases, the electrolyte and the gas tend to flow toward the outer cylinder 120, Taylor vortices are generated above the critical velocity. Taylor vortices are arranged in a very regular loop in the major axis direction and rotate in opposite directions, so they do not mix in the major axis direction and can induce uniform mixing. The rotational speed of the inner cylinder can be adjusted to 10,000 rpm to form a Kuett-Taylor vortex flow, preferably 20 to 10,000 rpm as described above.

Meanwhile, the uniformly mixed electrolyte and gas can be electrolyzed by applying a constant voltage or a constant current to the outer cylinder 120 and the inner cylinder 130. In this case, when one of the cylinders is the working electrode and the other is the counter electrode, if the outer cylinder 120 of the Kuett-Taylor reactor 100 is the working electrode, And the inner cylinder 120 may be used as a working electrode when the outer cylinder 130 is a counter electrode.

When the gas introduced into the inlet 140 of the Kuett-Taylor reactor 100 is electrolyzed using the two cylinders 120 and 130 as electrodes, the outlet 150 of the Kuett-Taylor reactor 100 is connected to the outside Is present in the cylinder 120 and the degree of electrolysis according to the position of the Kuett-Taylor reactor 100 can be confirmed by adding the terminal outlet 150 to the positions 151, 152, 153 and 154. If there is gas that can not be decomposed in the electrolyte discharged from the terminal discharge port 150, it can be supplied again to the injection port 140 of the Kuett-Taylor reactor 100 to perform electrolysis.

Example 1: Reduction of gas

N ₂ O was fed to the Kuett-Taylor reactor at a rate of 100 ml / min and a 0.3 M K ₂ SO ₄ aqueous solution adjusted to pH 12 was fed at a flow rate of 250 ml / min. At this time, the internal temperature of the reactor was adjusted to 25 ° C. When N ₂ O was dissolved at 25 ° C, the saturation concentration was 24.3 mM. The inner cylinder was rotated at an angular speed of 20 rpm to dissolve N ₂ O in a K ₂ SO ₄ solution to form a Cuat-Taylor vortex flow. Next, a constant voltage was applied to the outer cylinder and the inner cylinder of the Kuett-Taylor reactor, and N ₂ O was electrolyzed by applying a voltage to the working electrode to -0.5 V relative to the reference electrode. Due to the electrolysis, N ₂ O was reduced to N ₂ .

Experimental Example 1: Analysis of cyclic voltage-current change according to the concentration of gas dissolved in an electrolyte

In the method of reducing the gas using the Kuett-Taylor reactor according to the present invention, the change of the cyclic voltage according to the concentration of the gas dissolved in the electrolyte was examined and the results are shown in FIG.

The cyclic voltammetry (CV) behavior of the Pd electrode (area 0.196 ㎠) was analyzed according to the concentration of N ₂ O in 0.3 M K ₂ SO ₄ electrolyte. 99.9% N ₂ O gas was dissolved at 100 ml / min for 30 minutes in order to saturate N ₂ O in a 0.3 M aqueous K ₂ SO ₄ solution adjusted to pH 12. If the control under the atmospheric pressure the temperature of the solution to 25 ℃ dissolving the N ₂ O and a saturated concentration of 24.3 mM, it was analyzed by cyclic voltammetry by diluting the saturated solution to adjust the concentration of the electrolyte within the N ₂ O. Pd was used as a working electrode, a Pt mesh was used as a counter electrode, and a saturated calomel electrode (SCE) was used as a reference electrode. The voltage of the working electrode was changed from 1.0 V to -1.2 V and the scanning rate was changed from -1.2 V to 1.0 V at a scanning rate of 50 mV / s.

As shown in FIG. 3, it was confirmed that the peak current density (I _p ) changes according to the concentration of N ₂ O at a voltage of about -0.5 V (vs. SCE).

4 is a graph showing the calibration curve of I _p at the N ₂ O concentration obtained from FIG. 3 and the voltage near -0.5 V (vs. SCE). Referring to FIG. 4, it was confirmed that there is a linear correlation between the concentration of N ₂ O dissolved in 0.3 M K ₂ SO ₄ electrolyte on the Pd electrode and I _p .

Experimental Example 2: Analysis of gas solubility according to presence or absence of a Kuett-Taylor reactor

The solubility of the gas according to the use of the Kuett-Taylor reactor in the method of reducing the gas using the Kuett-Taylor reactor according to the present invention was examined. The results are shown in FIG.

For dissolution of the N ₂ O were fed the N ₂ O to 100 ml / min, 0.3 M of K ₂ SO ₄ electrolyte and dropped flowing at a flow rate of 250 ml / min, Koo eth- Taylor vortices of 20 rpm for the flow forming The inner cylinder was rotated at an angular speed.

As shown in FIG. 5, when the N ₂ O is dissolved in the Kuett-Taylor reactor without rotating the inner cylinder, it can be seen that the saturation concentration value is similar to that obtained when N ₂ O is saturated by simple agitation. On the other hand, when the internal cylinder was rotated at an angular speed of 20 rpm in a Kuett-Taylor reactor to form and dissolve a Kuett-Taylor vortex flow, the I _p of the saturated solution was 10.49 mA / cm 2, Which is about 19.1% higher. When the concentration of N ₂ O is converted to 30.1 mM using the calibration curve of FIG. 4, the solubility value is 23.9% higher than the conventional saturation concentration.

In addition, Ku eth- it can be seen that the Taylor vortex flow formed by dissolving the N ₂ O when the time until when N ₂ O is to be saturated can be reduced from about 8 minutes behind if it is not to form a vortex flow.

Although the present invention has been described with respect to a specific embodiment of a method for reducing a gas using a Kuett-Taylor reactor according to the present invention, it is apparent that various modifications can be made without departing from the scope of the present invention.

Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

It is to be understood that the foregoing embodiments are illustrative and not restrictive in all respects and that the scope of the present invention is indicated by the appended claims rather than the foregoing description, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

100: Couette-Taylor reactor
110: Driving motor 120: External cylinder
130: inner cylinder 140: inlet
150:
151, 152, 153, 154: side outlet

Claims (12)

Supplying an electrolyte and a gas to a Kuett-Taylor reactor including an outer cylinder and an inner cylinder;
Rotating the inner cylinder of the Kuett-Taylor reactor to uniformly mix the electrolyte and the gas; And
And applying a constant voltage or a constant current to the outer cylinder and the inner cylinder to electrolyze the mixture of the electrolyte and the gas.
The method according to claim 1,
The electrolyte is potassium sulfate (K ₂ SO _4), sodium hydroxide (NaOH), sodium chloride (NaCl), potassium hydroxide (KOH), potassium chloride (KCl), potassium nitrate (KNO _3), potassium carbonate (KHCO _3), first Characterized in that it is at least one selected from the group consisting of sodium phosphate (NaH ₂ PO ₄ ), dibasic sodium phosphate (Na ₂ HPO ₄ ) and sodium ascorbate (Na-ascorbate) Reduction method.
The method according to claim 1,
Wherein the concentration of the electrolyte is in the range of 0.01 to 0.5 M.
The method according to claim 1,
The gas is carbon monoxide (CO), carbon dioxide (CO _2), nitrogen monoxide (NO), nitrogen dioxide (NO _2), nitrous oxide (N ₂ O), diantimony nitrogen (N ₂ O _3), dinitrogen tetroxide (N ₂ O ₄ ), dinitrogen monoxide (N ₂ O ₅ ), sulfur dioxide (SO ₂ ) and sulfur trioxide (SO ₃ ).
The method according to claim 1,
Wherein the electrolyte and the gas are supplied at a rate of 1 to 500 ml / min.
The method according to claim 1,
Wherein the inner cylinder is rotated at 20 to 10,000 rpm. ≪ RTI ID = 0.0 > 18. < / RTI >
The method according to claim 1,
Wherein the inner cylinder is a counter electrode when the outer cylinder of the Kuett-Taylor reactor is the working electrode, and the inner cylinder is the working electrode when the outer cylinder is the counter electrode. .
The method according to claim 1,
The outer and inner cylinders of the Kuett-Taylor reactor are made of titanium (Ti), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt), copper (Cu) Wherein the foil including at least one member selected from the group consisting of gold (Au), indium (In), tin (Sn) and lead (Pb) is wrapped around the outside of stainless steel (SUS) Method of reducing gas using reactor.
The method according to claim 1,
The outer cylinder and the inner cylinder of the Kuett-Taylor reactor are made of stainless steel (Ti), iron (Fe), nickel (Ni), palladium (Pd), platinum (Pt) Wherein the alloy is a mixture of at least one selected from the group consisting of gold (Au), indium (In), tin (Sn) and lead (Pb) Reduction method.
The method according to claim 1,
Wherein the constant voltage is applied at -5.0 to 5.0 V. The method for reducing a gas using the CuTe-Taylor reactor.
The method according to claim 1,
Wherein the constant current is applied in a range of 0.1 mA to 5.0 A.
The method according to claim 1,
Wherein the gas decomposed after the electrolysis is supplied to the Guet-Taylor reactor to be electrolyzed to decompose the gas using the Kuet-Taylor reactor.

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