Catalyst for steam reforming of light oil, preparation method therefor, and method for producing hydrogen using same

Abstract

The present invention relates to a catalyst for steam reforming of light oil, a preparation method therefor, and a method for producing hydrogen using the catalyst for steam reforming of light oil. More specifically, the present invention discloses a catalyst for steam reforming of light oil, which is supported on a mesoporous SiO2 support and comprises one or more non-noble metal active materials selected from the group consisting of Ni, Co, Cu, and Fe, wherein carbon deposition is suppressed through interactions between the support and the active material during steam reforming of light oil, thereby promoting hydrogen production through steam reforming. According to the present invention, the catalyst can maintain a high specific surface area despite being prepared at a high firing temperature of 800°C, and has a strong interaction with the non-noble metal-based active material to exhibit high catalytic activity, thereby increasing hydrogen production efficiency.

Description

Catalyst for steam reforming of light oil, method for manufacturing the same, and method for producing hydrogen using the same

[0001] The present invention relates to a catalyst for steam reforming light oil, a method for manufacturing the same, and a method for producing hydrogen using said catalyst for steam reforming light oil. Specifically, the invention relates to a catalyst for steam reforming light oil in which a non-precious metal active material is supported on an SiO2 carrier.

[0002] Plastics are increasingly used worldwide due to their advantages, such as excellent durability, heat resistance, lightweight properties, and superior economic efficiency. However, with a recycling rate of only 9% for waste plastics, the problem of environmental pollution caused by plastic waste is becoming serious. As of 2016, the annual discharge of plastic waste into rivers, lakes, and oceans is estimated to be between 9 and 23 million tons, while the discharge into terrestrial environments is estimated at 13 to 23 million tons. Since the natural decomposition or removal rate of waste plastics ranges from decades to centuries, the rate at which plastics enter a region exceeds the natural removal or purification rate, leading to the accumulation of plastic waste. As such, plastics are considered "lowly reversible pollutants" because their discharge cannot be reduced and they remain in the environment for extended periods. Accumulated waste plastics can threaten living organisms through toxicity, accumulate in the form of microparticles or cause damage to biological organs, or restrict the movement of organisms by attaching to or entangling their locomotor organs.

[0003] To curb plastic waste, a resolution was adopted to prevent the indiscriminate influx of plastics into countries lacking plastic waste management systems through the Basel Convention, and to establish the first binding international agreement at the UN Environment Assembly to address the problem of plastic pollution. However, since reducing plastic usage is a realistically difficult task, technological development to increase recycling rates is crucial. Recycling methods for waste plastics include thermal recycling, which produces thermal energy from waste plastics; physical recycling, which processes waste plastics without altering their physical properties; and chemical recycling, which produces chemical raw materials. Thermal recycling emits greenhouse gases and environmental pollutants, similar to conventional incineration, while physical recycling has the disadvantage of being difficult to apply to plastics made of composite materials or those with high levels of contamination. Chemical recycling includes depolymerization, gasification, and pyrolysis methods; among these, pyrolysis is gaining attention due to its ability to utilize various waste plastic raw materials and its low initial investment costs.

[0004] Waste plastic pyrolysis is a technology that produces gas and pyrolysis oil by reacting waste plastics at high temperatures of 300–800°C under oxygen-free conditions. The generated gas is utilized as a heat source for the pyrolysis process. Pyrolysis oil consists of light oil, heavy oil, and high-boiling point waxes, and is used as a raw material or fuel to replace petroleum. However, among the pyrolysis oils, light oil cannot be sold or used as fuel due to the risk of explosion caused by its low flash point, making it necessary to process it or convert it into other substances.

[0005] As a solution to these problems, producing hydrogen from light oil derived from waste plastics via steam reforming offers the advantage of generating hydrogen as a clean energy source while simultaneously utilizing light oil that would otherwise be unsalable. However, to stably produce and supply high-quality, high-purity hydrogen gas over extended periods through this process, it is essential to first develop a customized catalyst with high activity that is suitable for the steam reforming of waste plastic-derived light oil.

[0006] In hydrocarbon reforming processes, catalyst performance is directly linked to operating costs and hydrogen production efficiency. Catalysts play a role in accelerating reactions by lowering the activation energy through contact with reactants, and catalysts composed primarily of metals and metal oxides are utilized in hydrocarbon reforming. Metal oxide catalysts consist of an active material, a support material that holds the active material, and a co-catalyst that enhances catalyst performance. Since the active material plays a crucial role in catalyst activity by facilitating the conversion of reactants, the selection of the active material is critical to ensuring excellent catalytic performance depending on the reaction.

[0007] Generally, precious metal catalysts are the most widely used catalysts for the steam reforming of hydrocarbons. While these catalysts are the most desirable in terms of hydrogen efficiency due to their high activity and stability even with low loading amounts, they have disadvantages in terms of economic feasibility and practicality for large-scale processes because they are susceptible to sintering at high temperatures and have high manufacturing costs. For this reason, research on the steam reforming of hydrocarbons using non-precious metal active materials is underway; however, the catalytic suitability of non-precious metal active materials for the steam reforming of light oil derived from waste plastics has not yet been studied.

[0008] Accordingly, the inventors prepared a steam reforming catalyst from various non-precious metal active materials such as Ni, Co, Cu, and Fe, and confirmed that the active material can be applied to a light oil reforming reaction derived from waste plastics to exhibit excellent hydrogen production characteristics, thereby completing the present invention.

[0009] Accordingly, the present invention has as its technical problem to provide a catalyst for steam reforming of light oil.

[0010] In addition, the present invention has another technical problem to solve by providing a method for manufacturing a catalyst for steam reforming of light oil.

[0011] In order to solve the above technical problem, the present invention,

[0012] Comprising one or more non-precious metal active materials selected from the group consisting of Ni, Co, Cu, and Fe, supported on a mesoporous SiO2 carrier,

[0013] A catalyst for steam reforming light oil is provided, characterized by inhibiting carbon deposition through the interaction between the carrier and the active substance during steam reforming of light oil and promoting hydrogen production through steam reforming.

[0014] In the present invention, the light oil is characterized as being a hydrocarbon having 7 to 12 carbon atoms derived from waste plastic.

[0015] In addition, in the present invention, the catalyst has a specific surface area of ​​at least 200 m² 2 It is characterized by being / g.

[0016] In addition, to solve the aforementioned other technical problems, the present invention,

[0017] A step of preparing a mesoporous SiO2 carrier by reacting a template material and a silica precursor by a hydrothermal synthesis method; and

[0018] A step of preparing a catalyst by impregnating the above-mentioned carrier with an aqueous solution of an active material precursor and then calcining it; including

[0019] A method for manufacturing a catalyst for steam reforming light oil is provided, characterized by manufacturing a catalyst for steam reforming light oil.

[0020] In addition, the present invention uses a catalyst for steam reforming light oil,

[0021] A method for producing hydrogen using a catalyst for light oil steam reforming is provided, characterized by producing hydrogen by reacting light oil and steam under reaction conditions of a reaction temperature of 650 to 800°C and a steam / carbon ratio of 1.5 to 3.0.

[0022] According to the present invention, a catalyst for steam reforming light oil can be provided, wherein a non-precious metal active material is supported on a SiO2 carrier having a mesoporous structure.

[0023] In addition, according to the method for manufacturing a catalyst for steam reforming light oil of the present invention, the catalyst can maintain a high specific surface area even though it is manufactured at a high calcination temperature of 800°C, and can increase hydrogen production efficiency by exhibiting high catalytic activity through strong interaction with the non-precious metal active material.

[0024] Figure 1 shows the synthesis process of a catalyst according to the present invention.

[0025] Figure 2 shows the TPR pattern of a catalyst according to one embodiment of the present invention.

[0026] Figure 3 shows the nitrogen adsorption / desorption curve (a) and pore distribution (b) of a catalyst of one embodiment of the present invention.

[0027] Figure 4 shows the XRD pattern analysis result of a catalyst according to one embodiment of the present invention.

[0028] Figure 5 shows the hydrogen production yield of a catalyst according to one embodiment of the present invention.

[0029] Figure 6 shows the light oil conversion rate of a catalyst according to one embodiment of the present invention.

[0030] Figure 7 shows the hydrogen production yield and light oil conversion rate of the catalyst according to the comparative example of the present invention.

[0031] The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the invention to specific embodiments, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. Similar reference numerals have been used for similar components in the description of each drawing.

[0032] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are intended to specify the presence of the features, numbers, steps, reactions, components, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, reactions, components, or combinations thereof.

[0033] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0034] The present invention relates to a catalyst for steam reforming light oil, which is supported on a SiO2 carrier having a mesoporous structure and comprises one or more non-precious metal active materials selected from the group consisting of Ni, Co, Cu, and Fe, thereby suppressing carbon deposition through the interaction between the carrier and the active material during steam reforming of light oil and promoting hydrogen production through steam reforming. The catalyst of the present invention is used for the production of hydrogen gas by the steam reforming reaction of light oil.

[0035] The above light oil refers to crude oil that contains a large amount of low molecular weight hydrocarbons in its composition, is light due to its low specific gravity, and has a relatively low boiling point, and may include light oil separated from waste plastic pyrolysis oil. According to one embodiment of the present invention, the light oil derived from waste plastic is obtained by separating heavy oil from waste plastic pyrolysis oil and contains hydrocarbons having 7 to 12 carbon atoms, and may include hydrocarbons having 7 to 9 carbon atoms as a major component.

[0036] The above light oil can generate hydrogen through a steam reforming reaction, and since the reforming reaction is an endothermic reaction that is advantageous at high temperatures, the production of hydrogen increases as the reaction temperature increases, and in the case of hydrocarbons with a high number of carbon atoms, even higher temperatures are required. This is because the steam reforming reaction of methane separated by the reforming reaction of hydrocarbons with a high number of carbon atoms occurs advantageously at high temperatures, which can increase the amount of hydrogen produced. Therefore, when steam reforming light oil, a temperature higher than the steam reforming reaction temperature of 500 to 800°C for general hydrocarbons is required.

[0037] The above active material is one or more non-precious metal active materials selected from the group consisting of Ni, Co, Cu, and Fe. The above non-precious metal active material provides excellent active sites in the steam reforming reaction of light oil and promotes the decomposition of carbon-hydrogen bonds, thereby enabling smooth hydrogen production. Specifically, Ni and Co perform the role of separating hydrogen present in hydrocarbons and can simultaneously promote the reforming reaction by decomposing CC bonds within the hydrocarbons, while Fe-based catalysts can exhibit activity in the hydrocarbon reforming reaction by decomposing CC bonds and CO bonds. Most preferably, Ni can be used.

[0038] However, while the above-mentioned non-precious metal active material has price competitiveness compared to conventionally used precious metal active materials, it has the disadvantage of the catalyst becoming deactivated due to carbon deposition, where carbon accumulates on the surface of catalyst particles during high-temperature reactions, and sintering, where catalyst particles clump together. Therefore, in order to apply the above-mentioned non-precious metal active material to high-temperature reactions including steam reforming of light oil, it is important to select an appropriate support to increase the thermal stability of the catalyst and ensure that the catalyst maintains a high degree of dispersion even at high temperatures.

[0039] In the present invention, the carrier is a mesoporous SiO2 carrier. The SiO2 carrier is thermally and chemically stable, so it can maintain its particle structure even at a high temperature of 1000°C, and its structure can be controlled to have a uniform pore structure during manufacturing. Therefore, when a catalyst is manufactured by supporting an active substance on the carrier, the active substance can be evenly dispersed, and hydrocarbon decomposition can be promoted by having a high specific surface area.

[0040] According to one embodiment of the present invention, the catalyst for steam reforming light oil according to the present invention uses SiO2 with a mesoporous structure having high thermal stability as a support material, thereby maintaining a high specific surface area even at a high calcination temperature of 800°C, and thus exhibiting high catalytic activity. Furthermore, since the catalyst according to the present invention is manufactured by supporting a non-precious metal active material on the SiO2 support with a mesoporous structure, even when the steam reforming catalyst manufactured therefrom is placed at high temperatures, the support and the active material can maintain a strong interaction, thereby maintaining high catalytic activity and enabling high durability.

[0041] In addition, the present invention provides a method for manufacturing a catalyst for steam reforming. Hereinafter, the method for manufacturing the catalyst will be explained in detail in steps with reference to Fig. 1, which shows the synthesis process of the catalyst according to the present invention.

[0042] First, the step involves preparing a mesoporous SiO2 carrier by reacting a template material with a silica precursor using a hydrothermal synthesis method. Although the specific surface area and pore size of the uniform mesoporous SiO2 carrier can be controlled by the synthesis method, they do not have a linear relationship with each other; therefore, an optimal specific surface area and pore structure exist depending on the manufacturing method, and accordingly, the surface area and pore characteristics of the catalyst on which the active material is supported may vary.

[0043] Specifically, a molding material and an acid solution are placed in distilled water and stirred, and then an alcohol solvent is added and stirred to prepare a mixed solution. The molding material is not particularly limited as a molding material for creating a mesoporous structure in the SiO2 carrier; any material that allows the pores formed in the SiO2 carrier after the removal of the mold to have a mesoporous structure may be used. As an example, various block copolymers such as Pluronic or Tetronic block copolymers, such as F108, F98, F88, P123, P105, and P104, may be used. Preferably, P123 may be used.

[0044] The above acid solution uses hydrochloric acid, sulfuric acid, etc., and the reaction must be carried out while maintaining a relatively high concentration of 1M to 2M to obtain a mesoporous material having an ordered structure. Preferably, hydrochloric acid is used.

[0045] As the above alcohol solvent, all of the commonly known alcohols such as methanol, ethanol, propanol, isopropanol, 1-butanol, and 2-butanol can be used, but 2-butanol is preferred.

[0046] Subsequently, a silica precursor is mixed into the above-mentioned mixed solution and stirred, then reacted in a hydrothermal synthesis reactor and dried to produce a solid product. The hydrothermal synthesis method is a method of synthesizing a material using water or an aqueous solution under high temperature and high pressure, and through the above hydrothermal synthesis, silica having a regular pore structure can be formed. Specifically, the solution mixed with the silica precursor can be reacted in the above-mentioned hydrothermal synthesis reactor at a temperature of 80 to 120°C for 20 to 24 hours, and then dried in an oven to produce a product.

[0047] Subsequently, the above product is filtered, washed, dried, and calcined to produce a SiO2 carrier with a uniform mesoporous structure. At this time, it is preferable to calcin at 600 to 1000°C.

[0048] Next, the step involves preparing a catalyst by impregnating the carrier with an aqueous solution of an active material precursor and then calcining it. A general method of impregnating in a solution can be used for impregnation, and it is preferable that the calcination be performed at 600 to 1,000°C.

[0049] Generally, in catalyst manufacturing, the calcination temperature must be higher than the reaction temperature. This is because the state of the metal and the support changes during the calcination process; therefore, calcination must be performed at a temperature higher than the reaction temperature before the reaction to prevent changes in the catalyst's properties during the reaction. Consequently, while the finally manufactured catalyst is used in the steam reforming process, the bonding strength between the active material and the support is increased, thereby preventing the catalyst from volatilizing and being lost, which can improve the durability and reaction characteristics of the catalyst. Therefore, if the calcination temperature is below 600°C, there are issues regarding the stability of the catalyst and the ease of removing impurities from the catalyst, and if it exceeds 1,000°C, there are issues regarding the difficulty of guaranteeing the desired reactivity due to the sintering of the active material and the interaction between the active material and the support. As a result, it is preferable that the calcination in the above step according to the present invention be performed at 600 to 1,000°C.

[0050] The catalyst prepared by the above steps may have a uniform mesopore structure with a size of 2 to 10 nm. If the pore size is less than 2 nm, the structural and thermal stability of the catalyst decreases during the reaction, which may lead to a decrease in catalyst activity due to sintering of the support during the catalyst preparation and reaction process. If it exceeds 10 nm, the specific surface area decreases, resulting in reduced catalyst activity. Therefore, it is preferable to have uniform mesopores of 2 to 5 nm to enhance catalyst performance.

[0051] In addition, the catalyst has a specific surface area of ​​at least 200 m² 2 It is desirable that / g. If the specific surface area is 200m² 2 If it is less than / g, the dispersibility of the active ingredient decreases, and catalytic activity decreases.

[0052] As such, the catalyst for steam reforming light oil according to the present invention is manufactured with a structure in which a non-precious metal active material is supported on a SiO2 carrier, and thus 200m despite high calcination temperatures 2 The mass transfer rate was increased by maintaining a high specific surface area of ​​more than 1g / g, and efficient hydrogen production was enabled by incorporating uniform mesopores to increase the contact area and catalytic activity between the light oil and the active material.

[0053] In another aspect, the present invention provides a method for producing hydrogen using a catalyst for steam reforming light oil. Specifically, light oil and steam are reacted at a reaction temperature of 650–800°C, a steam-to-carbon ratio of 1.5–3.0, and a space velocity of 10,000–150,000 mL·g cat -1 ·h -1 It is characterized by producing hydrogen by reacting under the reaction conditions. In this case, if the reaction temperature is below 650°C, the temperature is too low to supply sufficient energy for the chemical reaction to proceed, so sufficient catalytic activity cannot be expected; if it is above 800°C, it is undesirable because deactivation occurs due to phenomena such as the sintering of the active material at high temperatures. Regarding the steam / carbon ratio, if it is below the range specified above, the reaction proceeds similarly to the thermal decomposition of hydrocarbons, thus failing to utilize the advantages of the steam reforming reaction for obtaining abundant hydrogen gas; if it exceeds the range specified above, carbon generation is suppressed, but there is a problem of increased energy costs. Additionally, the space velocity is 10,000 mL·g cat -1 ·h -1If it is less than, the processing capacity of the reactant per unit catalyst is too low, which may reduce the production of the product per unit catalyst, and 150,000 mL·g cat -1 ·h -1 If it exceeds, heat transfer within the reactor becomes a problem, and the conversion rate of methane drops sharply, making it impossible to obtain the desired product yield.

[0054] In other words, if the reaction temperature, steam / carbon ratio, and space velocity ranges specified under the above reaction conditions are exceeded, there is a risk that the hydrogen production yield will decrease during the steam reforming reaction of light oil.

[0055] The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

[0056] <Example>

[0057] Catalyst manufacturing

[0058] The SiO2 support was prepared by a hydrothermal synthesis method using a tetraethylorthosilicate (TEOS) precursor and 35% HCl.

[0059] 6g of Pluronic P123 and 11.8g of 35% HCl were added to 217g of distilled water and stirred, and then 6g of butanol (Aldrich, 99.4%) was added while stirring at 25°C. After stirring for 1 hour, 12.9g of TEOS was added at 25°C and stirred, then placed in a sealed polypropylene reactor and heated at 100°C for 24 hours. The product obtained after heating was dried in a 100°C oven for 24 hours. The dried product was filtered, washed with distilled water until the pH reached 7.0, dried in a 100°C oven, and then calcined at 800°C.

[0060] The active materials Ni, Co, and Fe were each prepared by dissolving 5 wt.% of Ni(NO3)2·6H2O, Co(NO3)2·6H2O, and Fe(NO3)3·9H2O precursors in distilled water, then impregnating them onto a SiO2 support by an impregnation method, and then calcining at 800°C to produce Example 1 (Ni / SiO2), Example 2 (Co / SiO2), and Example 3 (Fe / SiO2).

[0061] <Comparative Example>

[0062] 13.8 mL of Tetraethlyorthosilicate (TEOS) was placed in a crucible and calcined at 800°C for 6 hours to obtain a specific surface area of ​​14 m² 2 Very low SiO2 was produced at / g.

[0063] The active substance Ni was prepared by dissolving a Ni(NO3)2·6H2O precursor in 5 wt.% distilled water, then impregnating it onto the SiO2 support using an impregnation method, and then calcining it at 800°C to produce a comparative example (5 wt.% Ni / SiO2).

[0064] Catalytic reaction

[0065] The experiment on the reforming reaction of light oil derived from waste plastics was carried out in a cylindrical quartz reactor with a diameter of 4–6 mm. 25 mg of catalyst was injected, and thermocouples were installed in the catalyst bed to measure and control the reaction temperature. Prior to the reforming reaction experiment, catalytic reduction was performed for 3 hours at 800°C in a 5% H2 / N2 gas atmosphere to activate the catalyst.

[0066] Dodecane, a standard substance, was used as the reactant. Dodecane is a substance with 12 carbon atoms and is the substance with the highest number of carbon atoms among the light oil components obtained from the waste plastic pyrolysis plant in Okcheon. Referring to Table 1, which shows the GC-MS analysis results of the light oil, the main components of the light oil consist of hydrocarbons with carbon atoms ranging from C7 to C9. However, since carbon deposition, which is a cause of catalyst deactivation, is preferred when hydrocarbons with high carbon atoms are used as raw materials, dodecane, which has the highest number of carbon atoms, was selected as the standard sample to create harsh conditions.

[0067] RT(min)FormulaNameArea(%)3.02C7H 14 1-Heptene8.33.16C7H 16 Heptane6.03.21C7H 12 3-Hexyne, 2-methyl-1.93.67C7H 14 Cyclohexane, methyl-1.54.75C7H8Toluene11.54.84C7H 12 Cyclohexane, methylene-1.35.54C8H 16 1-Octene 5.9 5.8 1C8H 18 Octane5.26.45C9H 20 Heptane, 2,4-dimethyl-1.56.77C9H 18 2,3,3-Trimethyl-1-hexene4.77.02C9H 18 2,4-Dimethyl-1-heptene10.57.58C8H 10 Ethylbenzene 5.68.39C 10 H 20 4-Nonene, 2-methyl-6.18.60C9H 20 Nonane2.610.63C 10 H 20 1-Decene1.410.88C 10 H 22 Octane, 3,5-dimethyl-1.012.16C 12 H 244-Octene, 2,3,6,7-tetramethyl-0.714.19C 12 H 26 Dodecane0.5

[0068] The catalytic reaction was at a reaction temperature of 800°C, a water vapor / carbon ratio of 2.5, and 27,690 mL·g cat -1 ·h -1 The experiment was performed at a space velocity of . Dodecane and water vapor were injected at 0.4 mL / min and 0.9 mL / min, respectively, and a preheater was installed to heat the dodecane to 330°C and the water vapor to 180°C so that they could be injected in vapor form. For the post-reaction gas, moisture and liquid products were removed using a -2°C constant temperature water bath and a desiccant, and then analyzed using micro gas chromatography (Agilent Micro GC-490).

[0069] <Test Example>

[0070] Catalyst Characterization

[0071] Characterization was performed to analyze the correlation between the performance and characteristics of the catalyst.

[0072] Since the reforming reaction of light oil derived from waste plastics is an oxidation-reduction reaction, to verify the reduction characteristics of the catalyst, a Temperature programmed reduction (TPR) was performed using AutoChem II 2920 by heating the catalyst from 50°C to 1,000°C at a rate of 10°C / min under 10% H2 / Ar gas conditions.

[0073] To determine the specific surface area and pore characteristics of the catalyst, the specific surface area of ​​the catalyst was determined using ASAP 2020, and N2 adsorption / desorption analysis was performed to determine the pore characteristics.

[0074] To verify the dispersion of metals in the catalysts, H2 chemisorption analysis was performed on the Ni / SiO2 catalyst, and CO chemisorption analysis was performed on the Co / SiO2 and Fe / SiO2 catalysts using AutoChem II 2920. Prior to the chemisorption analysis, the catalysts were reduced with 10% H2 / Ar gas at 800°C for 3 hours. After reduction, the temperature was lowered to 50°C, and H2 or Co gas was injected in pulses to induce chemisorption onto the catalysts.

[0075] X-ray diffraction (XRD) analysis was performed to confirm the crystallographic characteristics of the catalyst.

[0076] The analysis results of Examples 1 to 3 are shown in Figures 2 to 6.

[0077] Figure 2 shows the results of TPR analysis performed under temperature-elevated reduction to determine the reduction characteristics of the prepared catalyst. In the case of Example 1, in which Ni was supported as the active material, reduction peaks were observed at 670 and 784°C. Generally, for Ni / SiO2 catalysts, a reduction peak for Ni, which has weak interaction with the support, is observed at 400°C; however, this was not observed in Example 1. This result is attributed to the strong interaction between the active material Ni and the mesoporous SiO2, and due to this strong interaction, sintering and carbon deposition, which are causes of catalyst deactivation in the modification reaction, can be suppressed. In the case of Example 2, reduction peaks appeared at 370, 532, and 911°C. The peak observed at 370°C is the peak that appeared as Co3O4 was reduced to CoO, the peak at 532°C is the peak that appeared as CoO, which has weak interaction with SiO2, was reduced to Co, and the peak observed at 911°C is the peak that appeared as CoO, which has strong interaction with SiO2, was reduced to Co. In the case of Example 3, a catalyst in which Fe is supported as the active material, three peaks appeared. The first peak observed at 480°C is the peak that appeared as Fe3O4 was reduced to Fe2O3, the peak observed at 660°C is the peak that appeared as Fe2O3 was reduced to FeO, and the peak at 900°C is the peak that appeared as FeO was reduced to Fe. From the above results, since peaks with strong interactions between the active material and the support material are strongly observed in Examples 1 and 2, high stability of the catalyst and a resulting carbon deposition inhibition effect can be expected.

[0078] Figure 3 shows the nitrogen adsorption / desorption curve (a) and pore distribution (b) for analyzing the pore characteristics of the catalyst according to the present invention. Regardless of the type of active metal, the nitrogen adsorption / desorption curve (a) exhibited the H3 form of Hysteresis type VI for all Examples 1 to 3. The shape of the curve indicates that all examples possess a mesoporous structure. Referring to Figure 3(b), which shows the pore distribution, and Table 2, which shows the specific surface area, pore volume, and dispersion of the active material of the catalyst, all Examples 1 to 3 have uniform mesopores of 3.5 nm and an active material dispersion of 2.0% or more. The pore volume was highest in the order of Co / SiO2 > Ni / SiO2 > Fe / SiO2, and was 0.4 cm for all. 3 It can be confirmed that it has a value greater than or equal to / g. In addition, all of Examples 1 to 3 are 200m 2 It can be confirmed that it possesses a high specific surface area of ​​more than / g; this is because SiO2 was applied as a support, so it maintains a mesoporous structure despite the high calcination temperature of 800℃, resulting in 200m 2 It is assessed that it can maintain a high specific surface area of ​​more than / g and a uniform dispersion of active substances.

[0079] Catalyst specific surface area (m 2 / g) Pore size (cm 3 / g) Dispersion of active substance (%) Example 1 (Ni / SiO2) 217.79 0.44 3.0 Example 2 (Co / SiO2) 240.17 0.49 2.5 Example 3 (Fe / SiO2) 224.15 0.40 2.2

[0080] Referring to Figure 4, which shows the results of the small angle XRD pattern analysis of Examples 1 to 3, it can be confirmed that the mesopores have large pore sizes, as low angles of 1° or less were observed in all of Examples 1 to 3. The peak appearing at 2θ of 21° is the XRD diffraction peak of SiO2. In the case of Example 1, the diffraction peak of NiO appeared at 37.1, 44.5, 51.8, 62.8, and 76.3°. In the case of Example 2, the diffraction peak of Co3O4 appeared at 36.5, 44.3, 51.6, and 75.8°, and the diffraction peak of CoO appeared at 42.5 and 61.6°. In the case of Example 3, the diffraction peak of Fe2O3 appeared at 36°, and it was difficult to observe the remaining diffraction peaks due to the small crystal size. It has been stated that, generally, smaller crystal sizes exhibit higher dispersion; however, according to the results in Table 2, Example 1 showed the highest dispersion. This result is believed to be due to the fact that, in addition to crystal size, the size of the diffraction peaks may be reduced by the amorphous metal. Figure 5 shows the hydrogen production yield when Examples 1 to 3 were applied to the light oil reforming reaction. Hydrogen production yield is a catalyst performance indicator representing the amount of hydrogen that can be produced from light oil; increasing the hydrogen production volume of the process through the development of catalysts with high hydrogen yield is essential for the economical operation of the process for producing high-purity hydrogen from light oil derived from waste plastics. Reaction temperature of 800°C, water vapor / carbon ratio of 2.5, 27,690 mL·g cat -1 ·h -1Among the catalysts prepared under space velocity conditions, Example 1 showed the highest hydrogen production yield of over 7%, and the hydrogen production yields were observed in the order of Ni / SiO2 > Co / SiO2 > Fe / SiO2. It is believed that the Ni / SiO2 catalyst exhibits a relatively high hydrogen yield because its hydrocarbon decomposition performance is improved, as it maintains the dispersion of the active material Ni and a high specific surface area, while possessing high catalytic stability due to the strong interaction between Ni and SiO2.

[0081] Referring to Figure 6, the catalyst prepared differently from the hydrogen production yield results shows a light oil conversion rate of 30–40%, so it can be observed that the trend of the light oil conversion rate and the trend of the hydrogen production yield do not coincide. From this result, it can be understood that although the performance of breaking carbon-to-carbon bonds of hydrocarbons in light oil in Examples 1 to 3 is similar, the performance of breaking bonds between carbon and hydrogen within the hydrocarbon is superior in Example 1, in which Ni is supported as an active material.

[0082] In contrast, referring to Fig. 7, which shows the hydrogen production yield and light oil conversion yield when the comparative example is applied to the light oil reforming reaction, the comparative example exhibits a hydrogen production yield of 5% or less and a light oil conversion rate of 20% or less, even though it was carried out under the same reaction conditions as Examples 1, 2, and 3. This indicates that the comparative example is 14m 2 It can be understood that hydrogen production is impossible because, due to the low specific surface area of ​​ / g, the mass transfer rate is low and the contact area between the light oil and the active material and catalytic activity are suppressed, leading to easy carbon deposition at high temperatures.

[0083] Therefore, from the above results, the catalyst for steam reforming light oil according to the present invention is manufactured with a structure in which a non-precious metal active material is supported on a SiO2 carrier, and thus, despite the high calcination temperature of 800℃, 200m 2The mass transfer rate was increased by maintaining a high specific surface area of ​​greater than / g, and uniform mesopores of 3.5nm size were formed at 0.4cm 3 It contains a pore volume of 1 / g or more and has a high dispersion of active material of 2.0% or more to increase the contact area between the light oil and the active material and the catalytic activity. In addition, it was confirmed that using Ni as the active material among non-precious metal active materials in a non-precious metal catalyst for producing hydrogen from waste plastic-derived light oil can achieve a higher hydrogen production yield compared to using Fe or Co as active materials. Accordingly, the catalyst according to the present invention can be effectively applied to hydrogen production by being used as a catalyst in the steam reforming reaction of light oil.

[0084] The foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not to limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

1. Supported on a mesoporous SiO2 carrier and comprising one or more non-precious metal active materials selected from the group consisting of Ni, Co, Cu, and Fe, A catalyst for steam reforming light oil, characterized by inhibiting carbon deposition through the interaction between the carrier and the active substance during steam reforming of light oil and promoting hydrogen production through steam reforming.

2. In Paragraph 1, A catalyst for steam reforming light oil, characterized in that the light oil is a hydrocarbon having 7 to 12 carbon atoms derived from waste plastic.

3. In Paragraph 1, The above catalyst has a specific surface area of ​​at least 200 m² 2 A catalyst for steam reforming light oil, characterized by having a weight of / g.

4. A step of preparing a mesoporous SiO2 carrier by reacting a template material and a silica precursor by a hydrothermal synthesis method; and A step of preparing a catalyst by impregnating the above carrier with an aqueous solution of an active material precursor and then calcining it; including A method for manufacturing a light oil steam reforming catalyst, characterized by manufacturing a light oil steam reforming catalyst according to any one of claims 1 to 3.

5. Using the catalyst of any one of claims 1 to 3, A method for producing hydrogen using a catalyst for light oil steam reforming, characterized by reacting light oil and steam under reaction conditions of a reaction temperature of 650 to 800°C and a steam / carbon ratio of 1.5 to 3.0.

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