KR102590997B1 - Bubble Column Reactor Containing More than two molten layers for Catalytic pyrolysis of Hydrocarbon - Google Patents

Abstract

It relates to a bubble column reactor containing two or more layers of melt for a hydrocarbon catalytic pyrolysis reaction according to the present invention, and more specifically, to increase the catalytic pyrolysis rate of hydrocarbons while using a minimum amount of liquid melt catalyst, resulting in high yield without carbon deposition. It relates to a bubble column reactor for catalytic pyrolysis of hydrocarbons, capable of obtaining target pyrolysis products.

Description

Bubble Column Reactor Containing More than two molten layers for Catalytic pyrolysis of Hydrocarbon}

It relates to a bubble column reactor containing two or more layers of melt for a hydrocarbon catalytic pyrolysis reaction according to the present invention, and more specifically, to catalytically pyrolyze liquid or gaseous hydrocarbons in the presence of a liquid melt catalyst and a heat transfer fluid to produce hydrogen, carbon, Or, it relates to a bubble column reactor for catalytic thermal decomposition of hydrocarbons, which produces hydrocarbons with lower molecular weight than the input hydrocarbons.

A bubble column reactor is a tower-type reactor that has a large aspect ratio and is a device that introduces reactants into the bottom and allows the reaction to occur while floating. Compared to stirred tank reactors, bubble column reactors are widely used in chemical engineering due to their relatively low equipment costs, simple structure, and low operating costs due to low energy costs. Among various application fields, a bubble column reactor can also be applied to the thermal decomposition of hydrocarbons. The existing thermal decomposition process involves passing a heating tube for a short period of time to cause thermal decomposition.

However, the method of thermal decomposition by transferring heat to the reactant through the wall of the heating tube has a low heat transfer rate and low process efficiency. To compensate for this, a cushion that introduces a solid catalyst into the heating tube is applied, but among the thermal decomposition products of hydrocarbons One disadvantage was that carbon was deposited on the catalyst, causing deactivation.

Accordingly, the present invention proposes a method of thermally decomposing materials that are liquid at the thermal decomposition temperature, such as metals or salts, by receiving them in a bubble column reactor. In particular, when the melt performs a catalytic action in the reactor, unlike a solid catalyst, carbon deposition does not occur, and carbon, which has a relatively lower density than the melt such as metal or salt, is separated from the melt and floats to the upper layer of the reactor. In addition, the melt has a very high heat transfer rate, so it can quickly supply the heat needed for the reaction, making it effective in reducing the size of the reactor.

Meanwhile, the cost of the process also includes the cost of the melt, and if the amount of melt can be reduced or replaced with a cheaper melt, it will help reduce the process cost.

Korea Patent Publication No. 2018-0117951 (Publication date: 2018.10.30) Korean Patent Publication No. 2017-0143251 (Publication date: 2017.12.29)

The main purpose of the present invention is to solve the above-mentioned problems, and to provide a bubble column reactor that can obtain the target thermal decomposition product in high yield without carbon deposition by increasing the catalytic thermal decomposition rate of hydrocarbons while using a minimum amount of liquid molten catalyst. It is provided.

In order to achieve the above object, one embodiment of the present invention includes a pyrolysis reactor in which an inlet through which a liquid or gaseous hydrocarbon fluid flows is formed on one side, and an outlet through which a reaction product is discharged is formed on the other side; And a structure disposed inside the thermal decomposition reactor, accommodating liquid molten catalysts and heat transfer fluids with different specific gravity, and having the liquid molten catalyst layer and heat transfer fluid layer sequentially arranged from the inlet to the outlet of the thermal decomposition reactor. A catalytic reaction unit having a catalytic reaction unit, wherein the surface tension of the heat transfer fluid is 83 mN/m or more, and the liquid melt catalyst includes Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V, Cr is one or more metals selected from the group consisting of Ga, In, Sn, Bi, Te and Sb, and the layer thickness ratio of the liquid molten catalyst layer and the heat transfer fluid layer is 1: 0.1 to 10. to provide.

In a preferred embodiment of the present invention, the liquid melting catalyst may include a first metal and a second metal, and the first metal may be a metal with a higher melting point than the second metal.

In a preferred embodiment of the present invention, the first metal is one or more metals selected from the group consisting of Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V and Cr, and the second metal is It is one or more metals selected from the group consisting of Ga, In, Sn, Bi, Te, and Sb, and contains 3 wt% to 15 wt% of the first metal and 85 wt% to 97 wt% of the second metal, based on the total weight of the liquid molten catalyst. It may be characterized as containing wt%.

In a preferred embodiment of the present invention, the heat transfer fluid may include one or more compounds represented by the following formula (1).

[Formula 1]

MX

In Formula 1, M is selected from the group consisting of Li, Na, K, Sr, Ba, Mg, Ca, Mn, Zn, La, Co, Ni, Cu, Ce, Fe, Sc, Ti, V and Cr, is selected from the group consisting of F, Cl, Br, I, OH, SO ₃ and NO ₃

In a preferred embodiment of the present invention, the catalytic thermal decomposition reaction may be performed at 500°C to 1100°C.

According to the present invention, in converting hydrocarbons into hydrogen, carbon, and hydrocarbons with lower molecular weight than the input hydrocarbons by catalytic thermal decomposition, a liquid molten catalyst is used as a thermal decomposition catalyst, and at the same time, heat is transferred to the hydrocarbons through uniform contact between the liquid molten catalyst and the hydrocarbons. Efficiency can be improved, and as the melt itself acts as a catalyst, the time or energy required to cleave the carbon-hydrogen bonds of hydrocarbons can be reduced.

In addition, according to the present invention, the rate of thermal decomposition of hydrocarbons can be increased by increasing the residence time of hydrocarbons by slowing down the rising speed of injected hydrocarbon bubbles or droplets due to interfacial tension at the interface between the liquid melt catalyst and the heat transfer fluid, and increasing the hydrocarbon thermal decomposition rate. By reducing the ratio, the liquid molten catalyst only contributes to the formation of radicals at the beginning of the reaction, and by allowing the subsequent conversion reaction to proceed in a heat transfer fluid, the amount of liquid molten catalyst is minimized, increasing economic efficiency in commercialization processes such as scale up. You can do it.

Figure 1 is a schematic diagram of a bubble column reactor performing catalytic thermal decomposition of hydrocarbons according to an embodiment of the present invention.
Figure 2 is a graph measuring hydrogen yield according to catalytic thermal decomposition temperature in Examples 1 and 2 and Comparative Examples 1, 2, and 5 of the present invention.
Figure 3 is a graph measuring hydrogen yield according to catalytic thermal decomposition temperature in Examples 3 and 4 and Comparative Examples 3, 4, and 6 of the present invention.
Figure 4 is a graph measuring hydrogen yield according to the surface tension of the heat transfer fluid in Examples 1 and 2 and Comparative Examples 1 and 2 of the present invention.
Figure 5 is a graph measuring hydrogen yield according to the surface tension of the heat transfer fluid in Examples 3 and 4 and Comparative Examples 3 and 4 of the present invention.
Figure 6 is a graph measuring hydrogen yield according to the layer thickness ratio of the liquid molten catalyst layer and the heat transfer fluid layer in Examples 5 to 7 and Comparative Examples 8 and 9 of the present invention.

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

As used herein, terms such as “comprises,” “contains,” “includes,” or “has” indicate the presence of features, values, steps, operations, components, parts, or combinations thereof described in the specification. It refers to, and does not exclude the possibility that other features, values, steps, operations, components, parts, or combinations thereof not mentioned may exist or be added.

The present invention provides a thermal decomposition reactor in which an inlet is formed on one side through which liquid or gaseous hydrocarbon fluid flows, and on the other side, an outlet through which reaction products are discharged is formed; And a structure disposed inside the thermal decomposition reactor, accommodating liquid molten catalysts and heat transfer fluids with different specific gravity, and having the liquid molten catalyst layer and heat transfer fluid layer sequentially arranged from the inlet to the outlet of the thermal decomposition reactor. A catalytic reaction unit having a catalytic reaction unit, wherein the surface tension of the heat transfer fluid is 83 mN/m or more, and the liquid melt catalyst includes Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V, Cr is one or more metals selected from the group consisting of Ga, In, Sn, Bi, Te and Sb, and the layer thickness ratio of the liquid molten catalyst layer and the heat transfer fluid layer is 1: 0.1 to 10. It's about.

In the conventional catalytic thermal decomposition method of hydrocarbons, when a solid catalyst and a heat transfer fluid were used, carbon deposition on the solid catalyst accelerated during the decomposition of hydrocarbons such as methane after heat transfer, making it difficult to expect long-term efficiency, and when a liquid molten catalyst was used, There was a problem of low economic feasibility due to the use of large quantities of expensive liquid molten catalyst.

Accordingly, in the present invention, a liquid molten catalyst and a heat transfer fluid of two or more layers are used, but the heat transfer fluid has a specific gravity smaller than that of the liquid molten catalyst and can exhibit large interfacial tension at the interface with the liquid molten catalyst. Alternatively, by performing catalytic pyrolysis of the hydrocarbon fluid by arranging a liquid molten catalyst layer and a heat transfer fluid layer in the direction from the inlet into which the gaseous hydrocarbon fluid flows to the outlet, respectively, the first carbon of the hydrocarbon fluid with the highest activation energy is removed during pyrolysis. -Hydrogen bonds are cut in the liquid molten catalyst layer, and then a radical conversion reaction by hydrocarbon radicals with low activation energy occurs in the heat transfer fluid layer, which can reduce the content of liquid molten catalyst required for the thermal decomposition process of hydrocarbons, and the liquid molten catalyst and The rising speed of the hydrocarbon fluid is delayed due to interfacial tension at the interface between the heat transfer fluids, thereby improving the residence time and increasing the thermal decomposition rate of hydrocarbons.

Hereinafter, a preferred embodiment of a bubble column reactor using catalytic thermal decomposition of hydrocarbons according to the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a schematic diagram of a bubble column reactor performing catalytic thermal decomposition of hydrocarbons according to an embodiment of the present invention. Referring to FIG. 1, the bubble column reactor 100 according to the present invention includes a thermal decomposition reactor 10 and a catalytic reaction unit 50.

The thermal decomposition reactor 10 accommodates a liquid molten catalyst and a heat transfer fluid, which will be described later, therein to form a liquid molten catalyst layer and a heat transfer fluid layer, and receives a gaseous or liquid hydrocarbon fluid such as methane to be treated and catalytically decomposes the melt. The decomposition reactor can be used without limitation as long as it is a reactor applied to general thermal decomposition, and is preferably a bubble fluidized bed reactor that allows continuous processing and has low process costs.

The pyrolysis reactor 10 has an inlet 11 through which liquid or gaseous hydrocarbon fluid flows in on one side, and an outlet 12 and 13 through which unreacted reaction products after catalytic pyrolysis are discharged on the other side. do. The inflow of the liquid or gaseous hydrocarbon fluid may be supplied into the thermal decomposition reactor through one or more inlets formed in the thermal decomposition reactor. Preferably, the inlet is connected to the lower part of the thermal decomposition reactor to produce liquid or gaseous hydrocarbons. The fluid can be introduced into the liquid molten catalyst layer disposed at the bottom of the thermal decomposition reactor. In particular, as the liquid or gaseous hydrocarbon fluid is introduced into the lower part of the thermal decomposition reactor, the liquid or gaseous hydrocarbon fluid rises and sequentially contacts the liquid molten catalyst and the heat transfer fluid to achieve catalytic thermal decomposition. This increases the reaction area and increases the efficiency of heat and mass transfer, thereby maximizing decomposition efficiency.

In addition, in the thermal decomposition reactor 10, since the levitation of the liquid or gaseous hydrocarbon fluid due to the difference in specific gravity may be faster than the completion of the reaction, the height of the reaction reactor must be made sufficiently high or the height of the melted liquid molten catalyst and heat transfer fluid may be raised. The residence time of the liquid or gaseous hydrocarbon fluid in the liquid melt catalyst and heat transfer fluid can be increased through stirring, etc.

In order to maintain the liquid molten catalyst and heat transfer fluid in a molten state, the thermal decomposition reactor may additionally supply heat from an external heat source by a separate heating means such as a heater (not shown), thereby maintaining the liquid molten catalyst and heat transfer fluid in a molten state. Can be continuously maintained in a molten state and can receive the reaction heat necessary for thermal decomposition of liquid or gaseous hydrocarbon fluid.

The hydrocarbon fluid introduced into the thermal decomposition reactor can be applied without limitation as long as it is a hydrocarbon fluid in a liquid or gaseous state. For example, it may be methane, natural gas, etc., and inert gas and/or rain in addition to the hydrocarbon fluid in a liquid or gaseous state. May contain inert gas.

Hydrocarbons such as methane contained in the liquid or gaseous hydrocarbon fluid may be 2% (v/v) or more, more preferably 40% (v/v), based on the total volume of the liquid or gaseous hydrocarbon fluid supplied into the reactor. v/v) may be ~100% (v/v), and the inert gas and/or non-inert gas is 98% (v/v) or less, more preferably 60%, based on the total volume of the hydrocarbon fluid in the liquid or gas phase. It may be less than %(v/v).

Meanwhile, the catalytic reaction unit 50 disposed inside the thermal decomposition reactor increases heat transfer efficiency to the liquid or gaseous hydrocarbon fluid flowing into the thermal decomposition reactor and breaks the bonds and carbon-hydrogen bonds between the constituent molecules of the hydrocarbon fluid to form methyl radicals. It is intended to hydrogenate hydrocarbons by converting them into hydrogen radicals, and accommodates liquid molten catalysts and heat transfer fluids with different specific gravity, forming a liquid molten catalyst layer 60 and a heat transfer fluid layer ( 70) has a structure in which they are arranged sequentially.

The liquid molten catalyst layer 60 is formed of the liquid molten catalyst 61, and has a larger specific gravity than the heat transfer fluid layer, so it is disposed below the heat transfer fluid layer 70 in the catalytic reaction section due to the difference in specific gravity, and is either a liquid or gaseous hydrocarbon fluid. By cutting the bonds between hydrocarbon constituent molecules, the methyl radicals of the hydrocarbon fluid can be converted into carbon and hydrogen through C2, C3, aromatic compounds, etc. in a subsequent reaction in the heat transfer fluid layer 60, which will be described later.

The liquid melt catalyst 61 can be applied without limitation as long as it is a liquid melt catalyst capable of hydrogenating hydrocarbons. For example, Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V, Cr, Ga, It may be In, Sn, Bi, Te, Sb, etc., and may preferably include a first metal and a second metal in a molten state, wherein the first metal is a metal with a higher melting point than the second metal. It can be.

The first metal may be selected from the group consisting of Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V, Cr, and is preferably Ni, Mn, Fe, etc. in terms of decomposition efficiency. The second metal has a relatively lower melting point than the first metal, and can be used without limitation as long as it is a metal that alloys well with other metals. Preferably, it may be Ga, In, Sn, Bi, Te, and Sb. In addition, in the combination of the first metal and the second metal of the liquid melt catalyst, Ni-Bi may be even more preferable.

At this time, the liquid melt catalyst may include 3 wt% to 15 wt% of the first metal and 85 wt% to 97 wt% of the second metal, based on the total weight of the liquid melt catalyst. If the first metal is included in less than 3 wt% based on the total weight of the liquid melt catalyst, thermal decomposition may not occur properly due to lack of reactivity, or problems may arise where the product distribution width is too wide, and 15 wt% may occur. If it exceeds this, the first metal may not be sufficiently melted into the second metal, which may cause the first metal to become a starting point for carbon deposition and cause a decrease in activity.

In addition, if the second metal is included in less than 85 wt% based on the total weight of the liquid melt catalyst, the first metal may not be sufficiently melted and may cause carbon deposition, and if it exceeds 97 wt%, the first metal may not be sufficiently melted. In this case, problems may arise such as thermal decomposition not occurring efficiently due to lack of reactivity or the distribution range of the product being widened.

The molten metal catalyst of the present invention can liquefy existing metal catalysts at low temperatures by receiving two or more metals with different melting points in a molten liquid state in a thermal decomposition reactor, thereby improving heat transfer efficiency and thermal decomposition efficiency. A synergistic effect can be achieved to prevent activity decline.

Meanwhile, the heat transfer fluid layer 70 has a smaller specific gravity than the liquid molten catalyst and a surface tension of 83 mN/m or more, and the heat transfer fluid 71 contains one or more compounds among the compounds represented by the following formula (1): It can be preferably NaCl, NaBr, KCl, KBr, and more preferably NaCl.

[Formula 1]

MX

In Formula 1, M is selected from the group consisting of Li, Na, K, Sr, Ba, Mg, Ca, Mn, Zn, La, Co, Ni, Cu, Ce, Fe, Sc, Ti, V and Cr, X is selected from the group consisting of F, Cl, Br, I, OH, SO ₃ and NO ₃ .

If the surface tension of the heat transfer fluid is less than 83 mN/m, the interfacial tension is insufficient and the residence time of the hydrocarbon fluid cannot be increased as intended.

The liquid molten catalyst layer 60 and the heat transfer fluid layer 70 may be formed in the catalytic reaction unit 50 at a layer thickness ratio of 1:0.1 to 10, preferably 1:1 to 5. If the layer thickness ratio of the heat transfer fluid layer to the liquid molten catalyst layer is less than 1:1, the economic feasibility compared to the catalytic thermal decomposition effect is low as a large amount of expensive liquid molten catalyst is received, and the layer thickness of the heat transfer fluid layer to the liquid molten catalyst layer is reduced. If the ratio exceeds 1:10, the content of liquid molten catalyst may be low, which may cause problems with decomposition efficiency at low temperatures.

The liquid molten catalyst and heat transfer fluid in a molten state of the present invention have a large heat capacity and high thermal conductivity compared to fluidized sand, gas, or steam used in conventional pyrolysis, so they can quickly supply a large amount of heat to the hydrocarbon fluid, and the corresponding liquid molten catalyst And the heat transfer fluid has a larger specific gravity than the hydrocarbon fluid but has a low viscosity, so it can effectively penetrate the input hydrocarbon fluid and perform catalytic thermal decomposition. It is also effective in separation because it has a different specific gravity from the pyrolyzed reaction product.

The liquid or gaseous hydrocarbon fluid flowing into the catalytic reaction unit inside the thermal decomposition reactor 10 is catalytically decomposed by sequentially passing through the liquid molten catalyst layer 60 and the heat transfer fluid layer 70, and then through the discharge section of the thermal decomposition reactor. It is discharged through (12,13).

The liquid or gaseous hydrocarbon fluid introduced into the thermal decomposition reactor 10 is catalytically decomposed by the liquid molten catalyst layer and the heat transfer fluid layer to produce hydrogen, solid carbon, and hydrocarbons with a lower molecular weight than the introduced hydrocarbon as reaction products. , the reaction products can be smoothly separated by the difference in specific gravity between the liquid melt catalyst and the heat transfer fluid. The separated reaction product may be discharged to the outside through the discharge portions 12 and 13 of the thermal decomposition reactor. At this time, one or more discharge ports of the pyrolysis reactor may be formed depending on the pyrolyzed product. For example, hydrogen among the pyrolyzed products is discharged to the discharge portion 12 formed at the top of the pyrolytic reaction reactor. Solid carbon, etc. can be discharged through the discharge portion 13 formed on the upper side of the thermal decomposition reactor.

The catalytic pyrolysis is performed by controlling the temperature of the molten liquid molten catalyst and the heat transfer fluid. The temperature control of the liquid molten catalyst and the heat transfer fluid depends on the type of the liquid molten catalyst and the heat transfer fluid, the composition ratio of the pyrolyzed product, etc. It can be selected appropriately, preferably at 500°C to 1100°C, and preferably at 800°C to 1000°C. If the catalytic pyrolysis temperature is lower than 500°C, the molten catalyst may not melt and serve as a starting point for carbon deposition, and sufficient heat energy may not be supplied for pyrolysis, so the pyrolysis reaction may occur slowly, and the catalytic pyrolysis temperature may be lower than 1100°C. If it is high, heat energy is supplied excessively and energy is wasted, and molten catalysts or heat transfer fluids with low boiling points may evaporate and be lost.

The catalytic pyrolysis method of hydrocarbon fluid according to the present invention performs a catalytic pyrolysis reaction by supplying hydrocarbon fluid to the above-described bubble column reactor, thereby increasing the thermal decomposition rate of hydrocarbon fluid while using a minimum amount of liquid molten catalyst and at the same time eliminating the problem of carbon deposition. can be solved, and when catalytic pyrolysis is performed by repeatedly introducing hydrocarbon fluid, high value-added products such as hydrogen, naphtha, and low-molecular-weight monomers can be continuously obtained.

The thermal decomposition method of the present invention as described above will be explained in more detail through the following examples, but the present invention is not limited thereto.

<Example 1>

In a cylindrical pyrolysis reactor with a cross-sectional area of 3.4 cm ² and a length of 20 cm, a liquid molten catalyst layer mixed with 10 wt% Ni and 90 wt% Bi and a NaCl heat transfer fluid layer (surface tension 100 mN/m) were placed for 5 cm each. A bubble column reactor was manufactured including a catalytic reaction section formed to a length of 5 cm.

<Examples 2 to 4>

The same bubble column reactor as Example 1 was manufactured by combining the liquid melt catalyst and heat transfer fluid shown in Table 1 below.

<Comparative Examples 1 to 7>

The same bubble column reactor as Example 1 was manufactured by combining the liquid melt catalyst and heat transfer fluid shown in Table 1 below.

division Liquid molten catalyst layer heat transfer fluid layer Surface tension of heat transfer fluid (mN/m) Liquid melt catalyst Layer thickness (cm) heat transfer fluid Layer thickness (cm) Example 1 Ni-Bi 5 NaCl 5 100 Example 2 Ni-Bi 5 NaBr 5 85 Example 3 Sn 5 NaCl 5 100 Example 4 Sn 5 NaBr 5 85 Comparative Example 1 Ni-Bi 5 KCl 5 82 Comparative Example 2 Ni-Bi 5 KBr 5 72 Comparative Example 3 Sn 5 KCl 5 82 Comparative Example 4 Sn 5 KBr 5 72 Comparative Example 5 Ni-Bi 10 - - - Comparative Example 6 Sn 10 - - - Comparative Example 7 - - NaCl 10 100

<Experimental Example 1: Measurement of catalytic thermal decomposition performance according to thermal decomposition temperature>

To measure the catalytic thermal decomposition performance according to the thermal decomposition temperature, catalytic thermal decomposition was performed at 880°C, 910°C, 940°C, and 1000°C for 120 minutes under normal pressure using the bubble column reactor manufactured in Examples 1 to 4 and Comparative Examples 1 to 6. was performed respectively to measure the amount of hydrogen produced. The hydrocarbon fluid injected into the bubble column reactor used a methane-containing gas mixed with 90 vol% methane and 10 vol% nitrogen, and was injected into the bubble column reactor at a rate of 10 sccm. Hydrogen generated after the catalytic pyrolysis reaction was measured at 20-minute intervals using connected GC (Gas chromatography), and the yield was calculated based on the average value of the four points, discarding the maximum/minimum values. The results are shown in Figures 2 and 3. It was.

As shown in Figures 2 and 3, comparing the hydrogen yields of Examples 1 to 4 and Comparative Examples 1 to 6, the hydrogen yields of Examples 1 to 4 and Comparative Examples 1 to 4 were liquid phase melt under the same thermal decomposition temperature conditions. It was found to be higher than the hydrogen yield of Comparative Examples 5 and 6, which had only a catalyst layer, and showed the same tendency for each thermal decomposition temperature. Additionally, it was found that the hydrogen yield increased as the pyrolysis temperature increased.

<Experimental Example 2: Measurement of catalytic thermal decomposition performance according to surface tension>

In order to measure the catalytic pyrolysis performance according to the surface tension of each layer, catalytic pyrolysis was performed at 1000°C for 120 minutes under normal pressure using the bubble column reactor manufactured in Examples 1 to 4 and Comparative Examples 1 to 4, respectively. The amount of hydrogen produced was measured.

The hydrocarbon fluid injected into the bubble column reactor used a methane-containing gas mixed with 90 vol% methane and 10 vol% nitrogen, and was injected into the bubble column reactor at a rate of 10 sccm. Hydrogen generated after the catalytic pyrolysis reaction was measured at 20-minute intervals using connected GC (Gas chromatography), and the yield was calculated based on the average value of the four points, discarding the maximum/minimum values. The results are shown in Figures 4 and 5. It was.

As shown in Figures 4 and 5, when comparing the hydrogen yields of Examples 1 and 2 and Comparative Examples 1 and 2, and Examples 3 and 4 and Comparative Examples 3 and 4, the heat transfer fluid layer under the same pyrolysis temperature conditions When the surface tension was 83 mN/m or more (Examples 1 to 4), the increase in hydrogen yield compared to when only the liquid molten catalyst layer was provided was found to be significantly increased compared to Comparative Examples 1 to 4.

<Experimental Example 3: Measurement of catalytic thermal decomposition performance according to layer thickness>

In order to measure the catalytic pyrolysis performance according to the thickness of each layer, the thickness of the liquid molten catalyst layer and the heat transfer fluid layer were adjusted to the thicknesses shown in Table 2 below in the same bubble column reactor as in Example 3, and catalytic pyrolysis was performed at 1000 ° C. for 120 minutes. Afterwards, the amount of hydrogen produced was measured. The hydrocarbon fluid injected into the bubble column reactor used a methane-containing gas mixed with 90 vol% methane and 10 vol% nitrogen, and was injected into the bubble column reactor at a rate of 10 sccm. Hydrogen generated after the catalytic pyrolysis reaction was measured at 20-minute intervals using connected GC (Gas chromatography), and the yield was calculated based on the average value of the four points with the maximum/minimum values discarded, and the results are shown in Figure 6.

division Liquid molten catalyst layer heat transfer fluid layer Liquid melt catalyst Layer thickness (cm) heat transfer fluid Layer thickness (cm) Example 5 Ni-Bi 5 NaCl 5 Example 6 Ni-Bi One NaCl 9 Example 7 Ni-Bi 9 NaCl One Comparative Example 8 Ni-Bi 10 - - Comparative Example 9 - - NaCl 10

As shown in Figure 6, the hydrogen yields of Examples 5 to 7 were found to be about 20% to 40% higher than Comparative Examples 8 and 9, which were provided with only a liquid molten catalyst layer or only a heat transfer fluid layer, especially Examples 6 and 7. Likewise, it was confirmed that a hydrogen yield similar to Example 7 could be obtained even when the thickness of the liquid molten catalyst layer was thin. Additionally, in the comparison of Examples 10 and 11, it can be seen that the difference in hydrogen yield occurs significantly at the interface itself rather than before or after passing through the interface.

Accordingly, it was confirmed that when a composite reaction layer of a liquid molten catalyst layer and a heat transfer fluid layer is formed as in the present invention, a high hydrogen yield can be obtained even when a small amount of liquid molten catalyst is used. In addition, by showing that the difference in hydrogen yield depending on the position of the interface was not large, it was confirmed that the difference in hydrogen yield was caused by the delay of reactant bubbles or droplets, contrary to the prediction in the existing literature that the difference in hydrogen yield increases due to the crushing of bubbles at the interface.

Therefore, the bubble column reactor containing two or more layers of melt for hydrocarbon catalytic pyrolysis reaction according to the present invention can increase the thermal decomposition rate of hydrocarbon fluid while using a minimum amount of liquid melt catalyst and at the same time solve the carbon deposition problem. I was able to confirm.

Although the invention has been described with reference to the above-described embodiments, different embodiments may be constructed within the spirit and scope of the invention. Accordingly, the scope of the present invention is defined by the appended claims and their equivalents, and is not limited by the specific embodiments described herein.

10: Pyrolysis reactor
50: Catalytic reaction unit
60: Liquid molten catalyst layer
61: Liquid melt catalyst
70: heat transfer fluid layer
71: heat transfer fluid
100: bubble column reactor

Claims (6)

A pyrolysis reactor having an inlet formed on one side through which liquid or gaseous hydrocarbon fluid flows, and an outlet formed on the other side through which reaction products are discharged; and
It is disposed inside the thermal decomposition reactor, and has a structure in which liquid molten catalyst and heat transfer fluid with different specific gravity are accommodated, and the liquid molten catalyst layer and heat transfer fluid layer are sequentially arranged from the inlet to the outlet of the thermal decomposition reactor. Including a catalytic reaction unit;
In the catalytic reaction unit, the surface tension of the heat transfer fluid is 83 mN/m or more, and the liquid molten catalyst is Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V, Cr Ga, In, Sn, A bubble column reactor comprising at least one metal selected from the group consisting of Bi, Te, and Sb, and wherein the layer thickness ratio of the liquid molten catalyst layer and the heat transfer fluid layer is 1:0.1 to 10.
According to paragraph 1,
The liquid melt catalyst includes a first metal and a second metal, and the first metal is a metal with a higher melting point than the second metal.
According to paragraph 2,
The first metal is one or more metals selected from the group consisting of Ni, Co, Mn, Fe, Cu, Zn, Sc, Ti, V, and Cr, and the second metal is Ga, In, Sn, Bi, Te. and at least one metal selected from the group consisting of Sb.
According to paragraph 2,
The liquid molten catalyst is a bubble column reactor characterized in that it contains 3 wt% to 15 wt% of the first metal and 85 wt% to 97 wt% of the second metal, based on the total weight of the liquid molten catalyst.
According to paragraph 1,
A bubble column reactor, wherein the heat transfer fluid contains one or more compounds represented by the following formula (1):
[Formula 1]
MX
In Formula 1, M is selected from the group consisting of Li, Na, K, Sr, Ba, Mg, Ca, Mn, Zn, La, Co, Ni, Cu, Ce, Fe, Sc, Ti, V and Cr, X is selected from the group consisting of F, Cl, Br, I, OH, SO ₃ and NO ₃ .
According to paragraph 1,
A bubble column reactor, characterized in that the temperature of the liquid molten catalyst and heat transfer fluid is 500 ℃ ~ 1100 ℃.