Hydrorefining technique of mixed oil containing waste bio-oil

Abstract

The present disclosure provides a method for hydrotreating a mixed oil including a waste bio-oil and a waste plastic pyrolysis oil.SOLUTION: The method for producing refined oil including the method for hydrotreating mixed oil described above provides refined oil in which impurities are reduced to the level of the refined raw material, and in particular, oxygen impurities contained in a large amount are also significantly reduced.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure provides a method for hydrotreating a mixed oil containing waste bio-oil and waste plastic pyrolysis oil, and a method for producing a refined oil. [Background technology]

[0002] The more waste plastic is reused, the more its properties gradually deteriorate, and so it remains difficult to recycle, resulting in most plastics being disposed of as garbage. Discarded waste plastics are difficult to process due to their low density and large volume, and in particular, they take a long time to decompose naturally, causing serious soil pollution.

[0003] Biowaste includes agricultural by-products, oily waste, animal and vegetable oils and fats, and organic waste derived from living organisms. Most of these are disposed of as waste because they are inedible and have little industrial value. However, when such biowaste is disposed of, it generates a severe odor as it decays, making it very difficult to specify a disposal site, making it difficult to dispose of.

[0004] In order to solve these problems of waste plastics and waste biomass, and to solve problems such as reducing carbon dioxide, a substance that causes global warming, and increasing costs of crude oil, a method is known in which these materials are used as raw materials to convert them into usable oil.

[0005] However, waste plastic pyrolysis oil and waste bio-oil contain higher levels of impurities such as chlorine, nitrogen, and metals than fractions produced from crude oil using conventional methods. Therefore, they cannot be immediately used as high-value-added fuels such as gasoline and diesel, and must therefore undergo a refining process.

[0006] As described above, the purification method for removing impurities such as chlorine, nitrogen, and metals contained in waste plastic pyrolysis oil involves reacting the waste plastic pyrolysis oil with hydrogen in the presence of a hydrogenation catalyst to dechlorinate / denitrify it, or using a chlorine adsorbent to adsorb and remove the chlorine contained in the waste plastic pyrolysis oil.

[0007] However, waste bio-oil contains a large amount of oxygen that does not contribute to energy, and has the problem of being difficult to refine using the same hydrotreating process as the waste plastic pyrolysis oil described above. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present disclosure is to provide a method for hydrotreating a mixed oil that can hydrotreat a mixed oil containing a large amount of oxygen, the mixed oil including waste bio-oil and waste plastic pyrolysis oil.

[0009] An object of the present disclosure is to provide a method for hydrotreating a mixed oil containing waste bio-oil and a method for producing a refined oil by purifying the mixed oil.

[0010] An object of the present disclosure is to provide refined oil from a mixed oil containing waste bio-oil, with impurities reduced to the level of a refined raw material. [Means for solving the problem]

[0011] The present disclosure provides a method for hydrotreating a mixed oil containing waste plastic pyrolysis oil and waste bio-oil, in which the mixed oil is hydrotreated with a reaction gas containing hydrogen gas in the presence of a plurality of molybdenum-based hydrogenation catalysts, and the plurality of molybdenum-based hydrogenation catalysts may be two or more molybdenum-based hydrogenation catalysts each having a different metal support.

[0012] In one aspect of the present disclosure, the plurality of molybdenum-based hydrogenation catalysts may include a molybdenum-based hydrogenation catalyst including an alumina support and a molybdenum-based hydrogenation catalyst including a zirconia support.

[0013] In one aspect of the present disclosure, the mixed oil may be hydrotreated using a multi-stage catalyst layer, each catalyst layer being formed of a molybdenum-based hydrogenation catalyst containing a different metal support.

[0014] In one aspect of the present disclosure, the multi-stage catalyst layer may include a catalyst layer formed of a molybdenum-based hydrogenation catalyst including an alumina (AlO) support and a catalyst layer formed of a molybdenum-based hydrogenation catalyst including a zirconia (ZrO) support.

[0015] In one embodiment of the present disclosure, the mixed oil may contain 0.01 to 90 wt % of waste bio-oil relative to the total mass.

[0016] In one embodiment of the present disclosure, the waste bio-oil may contain 5% by weight or more of oxygen impurities based on the total mass.

[0017] In one aspect of the present disclosure, the waste bio-oil may have a boiling point of 200°C or higher.

[0018] In one embodiment of the present disclosure, the mixed oil may be hydrotreated at a reaction temperature of 330 to 500°C.

[0019] As one aspect of the present disclosure, in the mixed oil hydrotreating method, the hydrogen gas input may be 100 bar or less.

[0020] As one aspect of the present disclosure, in the method for hydrotreating mixed oil, the volume ratio of the hydrogen gas to the mixed oil input may be 300:1 to 3000:1.

[0021] In one embodiment of the present disclosure, the method for hydrotreating the mixed oil comprises hydrotreating the mixed oil at a liquid hourly space velocity (LHSV) of 0.1 to 10 h-1 may be.

[0022] The present disclosure can provide a method for producing a refined oil, including the steps of producing a product by the above-mentioned mixed oil hydrotreating method, and removing impurities contained in the product that have been hydrotreated.

[0023] In one embodiment of the present disclosure, the refined oil may contain, based on the total mass, 5 ppm or less of chlorine, 40 ppm or less of nitrogen, 5 ppm or less of sulfur, 5 wt. % or less of olefins, 1 wt. % or less of conjugated diolefins, and 5 ppm or less of metal-based compounds.

[0024] In one aspect of the present disclosure, the refined oil may contain less than 5% by weight of oxygen based on the total mass. [Effects of the Invention]

[0025] The mixed oil hydrotreating method according to the present disclosure can continuously hydrotreat mixed oil containing waste plastic pyrolysis oil and waste bio-oil for a long period of time.

[0026] The method for hydrotreating a blended oil according to the present disclosure can provide a refined oil with a significantly reduced content of the large amount of oxygen contained in the blended oil.

[0027] The method for producing refined oil according to the present disclosure can provide refined oil with significantly reduced impurity content by purifying impurities such as chlorine, nitrogen, sulfur, and metals contained in blended oil. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic diagram illustrating a method for hydrotreating a mixed oil according to one embodiment of the present disclosure. [Figure 2] 1 is a diagram illustrating a method for hydrotreating a mixed oil under a multi-stage catalyst layer according to one embodiment of the present disclosure. [Figure 3] 1 is a diagram illustrating a method for producing refined oil according to one aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0029] Unless otherwise defined, the technical and scientific terms used in this specification have the meanings that are commonly understood by a person of ordinary skill in the art to which this invention belongs, and in the following description, descriptions of known functions and configurations that may obscure the gist of this disclosure will be omitted.

[0030] Also, as used in this disclosure, the singular forms "a," "an," and "the" can be intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0031] Furthermore, units used in this disclosure unless otherwise specified are based on weight, and for example, units such as % or ratio mean % by weight or weight ratio, and unless otherwise defined, % by weight means the weight % of any one component of the total composition.

[0032] Furthermore, the numerical ranges used in this disclosure include the lower and upper limits, all values ​​within the range, increments logically derived from the form and width of the defined range, all values ​​limited therein, and all possible combinations of upper and lower limits of numerical ranges limited in different forms. Unless otherwise specified in the present specification, values ​​outside the numerical range that may occur due to experimental error or rounding of values ​​are also included in the defined numerical range.

[0033] The term "comprising" in this disclosure is an open-ended statement having the equivalent meaning of expressions such as "comprising," "containing," "having," or "featuring," and does not exclude further unrecited elements, materials, or steps.

[0034] The present disclosure can provide a method for hydrotreating a mixed oil, which includes a step of hydrotreating a mixed oil obtained by mixing waste plastic pyrolysis oil and waste bio-oil with a reaction gas containing hydrogen gas in the presence of multiple molybdenum-based hydrogenation catalysts.

[0035] The waste plastic pyrolysis oil refers to a mixture of hydrocarbon fractions produced by thermally decomposing waste plastics, where the waste plastics may include solid or liquid wastes related to synthetic polymer compounds such as waste synthetic resins, waste synthetic fibers, waste synthetic rubber, and waste vinyl.

[0036] The waste plastic pyrolysis oil may contain impurities such as chlorine compounds, nitrogen compounds, and metal compounds in addition to hydrocarbon fractions, and may also contain impurities in the form of chlorine, nitrogen, metals, etc. bonded to hydrocarbon compounds contained in the waste plastic pyrolysis oil.

[0037] The waste bio-oil can be produced from waste edible oil, sewage sludge, insect lipids, agricultural by-products, oily waste, animal and plant oil components, and biological waste organic matter through processes such as transesterification, pyrolysis, and fermentation.

[0038] The waste bio-oil may contain impurities such as chlorine, nitrogen, and sulfur, similar to the waste plastic pyrolysis oil, and may also contain impurities in the form of hydrocarbon compounds bound with chlorine, nitrogen, sulfur, etc. In particular, the waste bio-oil may contain a larger amount of oxygen impurities than the waste plastic pyrolysis oil.

[0039] That is, the waste bio-oil may need to be hydrotreated to remove a large amount of oxygen impurities. Furthermore, even if the waste bio-oil is a mixed oil mixed with waste plastic pyrolysis oil, which is produced in a higher yield than the waste bio-oil, a technology is required that can hydrotreat and remove oxygen impurities and other impurities in addition to oxygen impurities.

[0040] In one aspect of the present disclosure, the mixed oil hydrotreating method may use a plurality of molybdenum-based hydrogenation catalysts, and the plurality of molybdenum-based hydrogenation catalysts may each include two or more molybdenum-based hydrogenation catalysts having different metal supports.

[0041] The molybdenum-based hydrogenation catalyst may include, for example, one or more metal supports selected from alumina (AlO), silica (SiO), silica-alumina (SiO-AlO), titania (TiO), molecular bodies, zirconia (ZrO), aluminum phosphate (AlPO), carbon, and niobia (NbO).

[0042] The mixed oil hydrotreating method uses multiple molybdenum-based hydrogenation catalysts each having a different metal support, allowing for excellent hydrotreating and refining of a large amount of oxygen impurities and impurities such as nitrogen, chlorine, sulfur, and metals. Furthermore, the mixed oil hydrotreating method uses multiple molybdenum-based hydrogenation catalysts each having a different metal support, allowing for easy removal of impurities from the mixed oil without any special process.

[0043] In one aspect of the present disclosure, the plurality of molybdenum-based hydrogenation catalysts may include a molybdenum-based hydrogenation catalyst including an alumina support and a molybdenum-based hydrogenation catalyst including a zirconia support.

[0044] The molybdenum-based hydrogenation catalysts each include an alumina (Al2O3) support or a zirconia (ZrO2) support, and as described above, can hydrotreat impurities in mixed oils containing a large amount of oxygen impurities with excellent reactivity.

[0045] Furthermore, the molybdenum-based hydrogenation catalysts, which differ from each other in that they include an alumina (Al2O3) support or a zirconia (ZrO2) support, have excellent resistance to water generated when oxygen impurities are hydrotreated, preventing the hydrotreatment reaction of the catalyst from being reduced by the generated water and enabling the mixed oil to be hydrotreated with excellent hydrotreatment reactivity for a long period of time.

[0046] In one aspect of the present disclosure, the molybdenum-based hydrogenation catalyst may be a catalyst in which molybdenum metal and one or more metals selected from nickel, tungsten, cobalt, and the like are supported on the above-mentioned metal support.

[0047] Furthermore, the molybdenum-based hydrogenation catalyst may be one in which molybdenum and nickel or cobalt are supported on a metal support, or one in which a molybdenum-based metal and nickel are supported, in order to have excellent hydrogenation reactivity for impurities in a mixed oil containing waste plastic pyrolysis oil and waste bio-oil. However, this is not necessarily a limitation as long as the metal supports of the multiple molybdenum-based hydrogenation catalysts are different from each other and the hydrogenation reaction of the mixed oil is not impaired.

[0048] In yet another aspect of the present disclosure, the molybdenum-based hydrogenation catalyst may be a molybdenum-based sulfide hydrogenation catalyst in which sulfur is bound to molybdenum supported on a metal support, and the molybdenum-based sulfide hydrogenation catalyst is preferred from the viewpoint of purifying the mixed oil by hydrogenation treatment of sulfur impurities and oxygen impurities with high reactivity.

[0049] For example, the molybdenum-based hydrogenation catalyst may be one or more selected from the group consisting of NiMo / γ-Al2O3 and CoMo / γ-Al2O3, NiMo / γ-ZrO2 and CoMo / γ-ZrO2, or the plurality of molybdenum-based hydrogenation catalysts may include NiMo / γ-Al2O3 and NiMo / γ-ZrO2.

[0050] The molybdenum-based catalysts according to the above example are preferred because they have excellent hydrogenation reactivity and high water resistance, but are not necessarily limited thereto as long as they do not impair the hydrotreating reaction of the mixed oil.

[0051] In the mixed oil hydrotreating method according to one embodiment of the present disclosure, the mixed oil can be hydrotreated using the mixed oil hydrotreating system 1 described below.

[0052] 1, in a hydrotreating method according to an embodiment of the present disclosure, mixed oil is injected into a hydrotreating reactor 10 via a mixed oil supply line 20, and the mixed oil injected into the hydrotreating reactor 10 is hydrotreated in a catalyst layer 30 formed of a plurality of molybdenum-based hydrogenation catalysts. Next, a product formed by hydrotreating the mixed oil can be discharged through a product discharge line 40.

[0053] As described above, the catalyst layer 30 may include a plurality of molybdenum-based hydrogenation catalysts having different metal supports, and the metal support of each of the plurality of molybdenum-based hydrogenation catalysts may be an alumina (AlO) support or a zirconia (ZrO), but is not necessarily limited thereto.

[0054] In one aspect of the present disclosure, the mixed oil may be hydrotreated in a multi-stage catalyst layer, each catalyst layer being formed of a molybdenum-based hydrogenation catalyst containing a different metal support.

[0055] In the method for hydrotreating the mixed oil, a plurality of molybdenum-based hydrogenation catalysts having different metal supports may be formed in one catalyst layer as in the embodiment shown in FIG. 1 above, and the mixed oil may be hydrotreated. However, it is preferable to hydrotreat the mixed oil using a multi-stage catalyst layer in which each catalyst layer is formed of a molybdenum-based hydrogenation catalyst having a different metal support.

[0056] The multi-stage catalyst layer, in which each catalyst layer is formed of a molybdenum-based hydrogenation catalyst having a different metal support, can have excellent hydrogenation reactivity against each impurity contained in the mixed oil and high resistance to the hydrogenated impurities, thereby maintaining excellent hydrogenation reactivity for a long period of time.

[0057] As described above, the molybdenum-based hydrogenation catalysts having different metal supports forming the multi-stage catalyst layer may have different metal supports and the active metals supported on the metal supports may be the same or different. However, it is preferred that the active metals be the same in terms of having excellent hydrotreating reactivity under the same hydrotreating reaction conditions, but this is not necessarily a limitation.

[0058] The multi-stage catalyst layer formed with different molybdenum-based hydrogenation catalysts is preferred because it can selectively and excellently hydrogenate impurities such as chlorine, nitrogen, oxygen, sulfur, and metals contained in the mixed oil in each catalyst layer during the hydrotreatment reaction of the mixed oil.

[0059] In one embodiment of the present disclosure, the mixed oil hydrotreating method can hydrotreat the mixed oil in a mixed oil hydrotreating system 1 shown in FIG. 2 below.

[0060] 2, in a method for hydrotreating mixed oil according to one embodiment of the present disclosure, mixed oil is injected into a hydrotreating reactor 10 via a mixed oil supply line 20, and the injected mixed oil is sequentially brought into contact with an upper catalyst layer 30a and a lower catalyst layer 30b to undergo a hydrotreatment reaction. Next, a product produced by hydrotreating the mixed oil can be discharged through a product discharge line 40.

[0061] In the embodiment of FIG. 2 below, the mixed oil hydrotreating method is described as only performing a hydrogenation reaction of the mixed oil in the upper catalyst layer 30a and the lower catalyst layer 30b in the mixed oil hydrotreating system 1, but the multi-stage catalyst layer may be formed of three or more catalyst layers.

[0062] As described above, the multi-stage catalyst layer can be formed such that each catalyst layer contains a molybdenum-based hydrogenation catalyst having a different metal support.

[0063] The molybdenum-based hydrogenation catalyst included in each stage may be a catalyst in which a molybdenum-based metal and one or more metals selected from nickel, tungsten, and cobalt are supported on a metal support, or a catalyst in which a molybdenum-based metal and nickel or tungsten are supported, or a catalyst in which a molybdenum-based metal and nickel are supported, but is not necessarily limited thereto.

[0064] The molybdenum-based catalysts having different metal supports may have the same metal supported on the metal support, as long as they have excellent hydrogenation reactivity under predetermined reaction conditions. For example, a catalyst having a molybdenum-based metal and nickel supported thereon is preferred. However, this is not necessarily a limitation as long as a refined oil having the target impurity content in the present disclosure can be produced.

[0065] The two molybdenum-based hydrogenation catalysts, each having an alumina (Al2O3) support or a zirconia (ZrO2) support, can hydrogenate the large amount of oxygen impurities contained in the mixed oil with excellent reactivity, as described above. Furthermore, the multi-stage catalyst layer preferably includes the alumina-supported molybdenum-based hydrogenation catalyst and the zirconia-supported molybdenum-based hydrogenation catalyst in each stage, thereby providing each stage with higher resistance to the impurities produced by the hydrogenation treatment.

[0066] In one embodiment of the present disclosure, the mixed oil hydrotreating method can include a multi-stage catalyst layer including the above-mentioned molybdenum-based hydrogenation catalyst layer containing an alumina metal support and a molybdenum-based hydrogenation catalyst layer containing a zirconia support, in which the mixed oil is contacted with the alumina metal supported molybdenum-based hydrogenation catalyst and the zirconia supported molybdenum-based hydrogenation catalyst in that order.

[0067] The mixed oil hydrotreating method will be described with reference to FIG. 2 below. Mixed oil injected into a mixed oil supply line 20 may be sequentially contacted with an upper catalyst layer 30a and a lower catalyst layer 30b to undergo a hydrogenation reaction. Here, the upper catalyst layer 30a may be formed of an alumina metal-supported molybdenum-based hydrogenation catalyst, and the lower catalyst layer 30b may be formed of a zirconia-supported molybdenum-based hydrogenation catalyst.

[0068] The mixed oil hydrotreating method not only enables excellent hydrotreating of oxygen impurities contained in the mixed oil by sequentially contacting an alumina-supported molybdenum-based hydrogenation catalyst and a zirconia-supported hydrotreating catalyst, but also allows the zirconia-supported molybdenum-based hydrogenation catalyst layer to have significantly excellent water resistance, thereby continuously providing excellent hydrogenation reactivity of the mixed oil.

[0069] Therefore, the mixed oil hydrotreating method uses the above-mentioned multi-stage catalyst layer and molybdenum-based hydrogenation catalysts with different metal supports, which have excellent hydrogenation reactivity for the mixed oil containing waste bio-oil, and can remove hydrotreated impurities to produce refined oil with an extremely low impurity content.

[0070] In one aspect of the present disclosure, the waste plastic pyrolysis oil may contain impurities such as nitrogen, chlorine, sulfur, and metals in the form of single compounds or in the form bound to hydrocarbon compounds, as described above, and may further contain olefins having 6 or less carbon atoms and conjugated diolefins having 6 or less carbon atoms.

[0071] The waste plastic pyrolysis oil may contain, relative to its total mass, 300 ppm or more of nitrogen (N), 30 ppm or more of chlorine, and 100 ppm or less of sulfur, and may contain 20% by mass or more of olefins and 1% by mass or more of conjugated diolefins under conditions of 1 atmosphere and 25°C. However, this may vary depending on the waste plastics that are used as the raw material for the waste plastic pyrolysis oil, and is not necessarily limited thereto.

[0072] The waste plastic pyrolysis oil may have a hydrocarbon fraction content of 10 or more carbon atoms of 30% by weight or more, 40% by weight or more, 50% by weight or more, and 95% by weight or less, or 90% by weight or less, for example, 30 to 95% by weight, 40 to 95% by weight, or 50 to 95% by weight.

[0073] Waste plastic pyrolysis oil containing a hydrocarbon fraction having a carbon number of 10 or more in the above range is preferable because the refined oil produced by hydrogenation and the hydrogenation-treated impurity removal process has excellent compatibility, but this is not necessarily a limitation.

[0074] In one aspect of the present disclosure, the waste bio-oil can be produced from waste bio-materials such as waste cooking oil, sewage sludge, insect lipids, agricultural by-products, oily waste, animal and plant oil and fat components, and biological waste organic matter, as described above.

[0075] The waste bio-oil may contain, based on its total mass, 100 ppm or more of nitrogen (N), 10 ppm or more of chlorine (Cl), and 10 ppm or less of sulfur (S), although this may vary depending on the waste bio-oil used to produce it.

[0076] In one embodiment of the present disclosure, the waste bio-oil may contain oxygen impurities in an amount of 5 wt% or more, 10 wt% or more, 15 wt% or more, 20 wt% or more, 45 wt% or less, 40 wt% or less, 35 wt% or less, or 30 wt% or less, based on the total mass, for example, 10 to 50 wt%, 15 to 50 wt%, or 20 to 50 wt%.

[0077] The waste bio-oil may contain not only impurities such as nitrogen, chlorine, and sulfur, but also a large amount of oxygen impurities within the above range. The mixed oil hydrotreating method can hydrotreat the waste bio-oil with excellent reactivity even when it contains a large amount of oxygen impurities within the above range, and can produce refined oil with a significantly reduced content of oxygen impurities.

[0078] In one aspect of the present disclosure, the waste bio-oil may have a boiling point of 200°C or more, 205°C or more, 210°C or more, 215°C or more, or 220°C or more, and may be, but is not limited to, 250°C or less or 240°C or less.

[0079] The waste bio-oil may contain a large amount of hydrocarbon fractions having a carbon number of 14 or more and have a high boiling point within the above-mentioned range. The mixed oil hydrotreating method is preferable because it can hydrotreat the mixed oil to be hydrotreated with excellent reactivity even if it contains waste bio-oil with a high boiling point.

[0080] In one embodiment of the present disclosure, the mixed oil may contain waste bio-oil in an amount of 0.01 wt % or more, 0.1 wt % or more, 0.5 wt % or more, 1 wt % or more, 5 wt % or more, 10 wt % or more, 20 wt % or more, or 50 wt % or less, 80 wt % or less, 90 wt % or less, or 100 wt % or less, based on the total mass of the mixed oil, for example, 0.01 to 90 wt %, 0.1 to 50 wt %, 0.5 to 50 wt %, 1 to 50 wt %, 5 to 50 wt %, 10 to 50 wt %, or 20 to 50 wt %.

[0081] That is, the hydrotreating method is preferable because it can effectively hydrotreat impurities such as nitrogen, chlorine, sulfur, metals, and especially oxygen contained in the mixed oil through an excellent hydrogenation reaction even when the mixed oil contains up to 50% by weight of waste bio-oil containing a large amount of oxygen impurities, and can easily remove the hydrogenated impurities later. However, this is not necessarily limited as long as it can produce the refined oil with reduced impurities targeted in the present disclosure.

[0082] Therefore, the mixed oil hydrotreating method can provide a method for producing refined oil having high purity by hydrotreating and purifying impurities such as oxygen, nitrogen, chlorine, sulfur, metals, olefinic compounds, and conjugated diolefins contained in mixed oil containing a large amount of oxygen impurities.

[0083] In one aspect of the present disclosure, the method for hydrotreating a mixed oil can hydrotreat the mixed oil using a reaction gas containing hydrogen gas in the presence of a plurality of molybdenum-based hydrogenation catalysts.

[0084] In one embodiment of the present disclosure, the mixed oil hydrotreating method may be performed at an input pressure of hydrogen gas of 100 bar or less, 90 bar or less, 80 bar or less, 70 bar or less, 20 bar or more, 30 bar or more, 40 bar or more, or 50 bar or more, for example, 20 to 100 bar, 20 to 90 bar, 20 to 80 bar, 20 to 70 bar, 30 to 70 bar, 40 to 70 bar, or 50 to 70 bar.

[0085] The pressure of the hydrogen gas introduced in the hydrotreating process of the mixed oil is 50 cm 3 The volume of the reactor may be measured at a hydrogen gas pressure that is recognizable to a person skilled in the art, but the volume of the reactor is merely an example and is not particularly limited as long as the pressure is within the range of the hydrogen gas pressure that can be recognized by a person skilled in the art.

[0086] The hydrotreating method can hydrotreat impurities contained in the mixed oil by introducing hydrogen gas at a pressure within the above-mentioned range and utilizing the excellent hydrogenation reactivity of the mixed oil. Furthermore, a hydrotreating method driven by a hydrogen pressure within the above-mentioned range is preferred because it can ensure worker safety and suppress the generation of NH4Cl impurities and the rate of increase in differential pressure within the reactor. However, this is not necessarily a limitation as long as it satisfies the target impurity reduction of the present disclosure.

[0087] In one embodiment of the present disclosure, the liquid hourly space velocity (LHSV) of the mixed oil hydrotreating method is 0.1 h -1 More than 0.3h -1 More than 0.5h -1 That's it, 1.0h -1 That's it, 2.0 hours -1 That's all, 10.0h -1 Below, 8.0h -1 Below, 5.0h -1 For example, 0.1 to 10 hours -1, 0.3~8h -1 or 0.5 to 5 hours -1 can be carried out in

[0088] The step of hydrotreating at a liquid hourly space velocity within the above range is preferable because it enables stable hydrotreating of the mixed oil and easily removes hydrogenated impurities contained in the product obtained by hydrotreating the mixed oil, as will be described later, to obtain a refined oil of high purity, but this is merely an example and is not necessarily limiting.

[0089] In one embodiment of the present disclosure, in the mixed oil hydrotreating method, the volume ratio of the input hydrogen gas to the mixed oil (gas-to-oil ratio) may be 300:1 to 3000:1, and in another embodiment, the volume ratio may be 500:1 to 2500:1 or 800:1 to 1500:1.

[0090] A method for hydrotreating a mixed oil that satisfies the above-mentioned range of GOR is preferred because it can provide excellent hydrotreating efficiency for the mixed oil and also ensure reaction stability.

[0091] In one embodiment of the present disclosure, the reaction temperature in the mixed oil hydrotreating method may be 330° C. or higher, 340° C. or higher, 350° C. or higher, 360° C. or higher, 370° C. or higher, 380° C. or higher, 390° C. or higher, and 500° C. or lower, 490° C. or lower, 480° C. or lower, 470° C. or lower, 460° C. or lower, 450° C. or lower, 430° C. or lower, or 400° C. or lower. For example, the reaction temperature may be 330 to 500° C., 330 to 450° C., or 350 to 450° C.

[0092] The mixed oil hydrotreating method satisfying the reaction temperature range is preferred because it improves the efficiency of the mixed oil hydrotreating, thereby significantly reducing the impurity content of the refined oil produced by hydrotreating the mixed oil.

[0093] In addition, a hydrotreating method satisfying the reaction temperature range described above is preferable because it can hydrotreat impurities without deteriorating the hydrocarbon fraction having 10 or more carbon atoms contained in the mixed oil and without increasing the content of impurities such as additional olefins and conjugated diolefins. However, this is not necessarily limited as long as the mixed oil can be hydrotreated.

[0094] Therefore, the mixed oil hydrotreating method can purify the impurities contained in the mixed oil by hydrotreating the mixed oil containing waste bio-oil and waste plastic pyrolysis oil containing a large amount of oxygen impurities using the above-mentioned molybdenum-based hydrogenation catalyst, multi-stage catalyst layers, and hydrotreating reaction conditions.

[0095] The present disclosure can provide a method for producing a refined oil, including the steps of producing a product by the mixed oil hydrotreating method and removing impurities hydrotreated in the product.

[0096] The hydrotreated impurities contained in the product may include hydrogen sulfide gas (H2S), hydrogen chloride (HCl), ammonia (NH3), water vapor (H2O), and small amounts of methane (CH4) and ethane (C2H6), which are produced by hydrotreating impurities such as nitrogen, chlorine, sulfur, and oxygen contained in the mixed oil.

[0097] The hydrotreated impurities are discharged through the steam outlet of the reactor in the impurity removal step, and finally, refined oil can be obtained.

[0098] In one embodiment of the present disclosure, the method for producing refined oil can produce refined oil from the above-mentioned products using a mixed oil hydrotreating system 1 and an impurity removal system 2 according to the embodiment of Figure 3 below.

[0099] Referring to FIG. 3, the mixed oil is subjected to a mixed oil hydrotreating system 1, and the product produced by the hydrogenation reaction of the mixed oil is injected into a refinery reactor 50 via a product supply line 60. Hydrotreated impurities contained in the injected product are removed via a hydrotreated impurity discharge line 70, and refined oil from which the impurities have been removed can be obtained.

[0100] In FIG. 3 below, the product supply line 60 may be connected to the product discharge line 40 in FIG. 2 below, which allows the method for producing refined oil to perform the steps of producing a product by hydrotreating a mixed oil and removing hydrotreated impurities contained in the product in a continuous process, thereby providing excellent processability.

[0101] In one embodiment of the present disclosure, the refined oil may contain, based on the total mass, 5 ppm or less of chlorine, 40 ppm or less of nitrogen, 5 ppm or less of sulfur, 5 wt. % or less of olefins, 1 wt. % or less of conjugated diolefins, and 5 ppm or less of metal-based compounds.

[0102] The impurity content of the refined oil can be determined by analyzing the components of the hydrotreated impurities discharged from the hydrotreated impurity discharge line 70 in FIG. 3 below using 2D gas chromatography (2D-GC) and calculating the hydrotreated impurity components analyzed by 2D-GC based on the total boiling point.

[0103] The refined oil from which impurities have been removed to the above content range is preferable because, even though it contains a large amount of waste bio-oil, the contained impurities can be hydrotreated by the above-mentioned hydrotreatment method, which has excellent processability, without the need for additional special processes.

[0104] In yet another embodiment of the present disclosure, the refined oil may contain chlorine of 5.0 ppm or less, 4.9 ppm or less, 4.5 ppm or less, 4.0 ppm or less, 3.0 ppm or less, 2.5 ppm or less, 2 ppm or less, 1.5 ppm or less, 1.3 ppm or less, 1.0 ppm or less, or 0.8 ppm or less, based on the total mass of the refined oil. The lower limit is not limited, and the refined oil may contain no chlorine, or 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more.

[0105] In yet another embodiment of the present disclosure, the refined oil has a nitrogen content of 40.0 ppm or less, 35.0 ppm or less, 34.3 ppm or less, 30.0 ppm or less, 35.0 ppm or less, 30.0 ppm or less, 20.0 ppm or less, 19.2 ppm or less, 19.0 ppm or less, 15.0 ppm or less, 10.0 ppm or less, 7.0 ppm or less, 6.5 ppm or less, 6.4 ppm or less, 6.0 ppm or less, 5. It may contain 8 ppm or less, 5.6 ppm or less, 5.3 ppm or less, 5.0 ppm or less, 4.5 ppm or less, 4.3 ppm or less, 4.0 ppm or less, 3.5 ppm or less, 3.0 ppm or less, 2.5 ppm or less, 2.0 ppm or less, 1.5 ppm or less, or 1.0 ppm or less, and although there is no lower limit, it may contain no nitrogen or may have a nitrogen content of 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more.

[0106] In yet another aspect of the present disclosure, the refined oil may contain, by total mass, sulfur in an amount of 5.0 ppm or less, 4.0 ppm or less, 3.0 ppm or less, 2.8 ppm or less, 2.5 ppm or less, 2.0 ppm or less, 1.6 ppm or less, 1.4 ppm or less, 1.1 ppm or less, 1.0 ppm or less, or less than 1.0 ppm, and may contain, but is not limited to, zero sulfur, or sulfur in an amount of 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more.

[0107] In yet another embodiment of the present disclosure, the refined oil may have a metal-based compound concentration of 5.0 ppm or less, 4.8 ppm or less, 4.5 ppm or less, 4.4 ppm or less, 4.0 ppm or less, 3.5 ppm or less, 3.2 ppm or less, 3.1 ppm or less, 3.0 ppm or less, 2.5 ppm or less, 2.0 ppm or less, 1.6 ppm or less, 1.5 ppm or less, 1.0 ppm or less, or less than 1.0 ppm, and although the lower limit is not limited, the refined oil may be free of metal-based compounds or may have a metal-based compound concentration of 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more.

[0108] In yet another embodiment of the present disclosure, the refined oil may have an olefin content of 5.0 wt% or less, 4.0 wt% or less, 3.0 wt% or less, 2.5 wt% or less, 2.2 wt% or less, 2.0 wt% or less, 1.8 wt% or less, 1.5 wt% or less, 1.4 wt% or less, 1.1 wt% or less, 1.0 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.1 wt% or less, or less than 0.1 wt%, based on the total mass of the refined oil; and, without limiting the lower limit, the refined oil may have no olefins or an olefin content of 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more.

[0109] In one aspect of the present disclosure, the refined oil may have conjugated diolefins of 1.0 wt. % or less, 0.8 wt. % or less, 0.5 wt. % or less, 0.2 wt. % or less, 0.1 wt. % or less, or less than 0.1 wt. % based on the total mass of the refined oil, and may have, without limitation, no conjugated diolefins or 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more of conjugated diolefins.

[0110] The refined oil containing the impurities of chlorine, nitrogen, sulfur, metals, olefins, and conjugated diolefins within the above ranges can be produced from a mixed oil containing waste plastic pyrolysis oil and waste bio-oil with excellent processability without any additional process steps.

[0111] The method for producing refined oil is preferred because it can achieve an excellent purification rate of impurities such as chlorine, nitrogen, sulfur, metals, olefins, and conjugated diolefins contained in a mixed oil containing waste plastic pyrolysis oil and waste bio-oil, and is particularly excellent in purification rate of chlorine and nitrogen.

[0112] That is, refined oil containing the impurities of chlorine, nitrogen, sulfur, metals, olefins, and conjugated diolefins within the above ranges is preferably purified to the level of a refinery feedstock, and can be used as a raw material to replace crude oil. This is preferable because it does not cause environmental pollution problems caused by fossil fuels and does not reduce productivity due to unstable crude oil prices.

[0113] In one embodiment of the present disclosure, the refined oil may contain less than 5% by weight, less than 4.0% by weight, less than 3.5% by weight, less than 3.0% by weight, less than 2.0% by weight, less than 1.5% by weight, less than 1.2% by weight, less than 1.0% by weight, less than 0.5% by weight, less than 0.4% by weight, 0.3% by weight or less, 0.2% by weight or less, 0.1% by weight or less, or less than 0.1% by weight, based on the total mass of the refined oil; and may contain, without limitation, no oxygen, or 0.001 ppm or more, 0.005 ppm or more, or 0.01 ppm or more of oxygen.

[0114] The refined oil may be produced by hydrotreating a mixed oil containing a waste bio-oil containing a large amount of oxygen, or may be produced by removing oxygen impurities from the mixed oil so that the oxygen content falls within the above range.

[0115] Therefore, the method for producing refined oil can produce refined oil with high purity even when waste bio-oil containing a large amount of oxygen impurities is mixed with waste plastic pyrolysis oil, and the hydrogenation treatment method can provide a variety of inputs by simultaneously inputting waste bio-oil containing a large amount of oxygen, rather than only inputting waste plastic pyrolysis oil.

[0116] The mixed oil hydrotreating method and the refined oil manufacturing method including the same according to the present disclosure will be described in more detail below with reference to examples. However, the following examples are merely a reference for explaining the present disclosure in detail, and the present disclosure is not limited thereto and can be realized in various forms. Furthermore, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. Furthermore, the terms used in the description in this disclosure are merely for the purpose of effectively describing specific examples and are not intended to limit the present disclosure.

[0117] [Measurement method] 1. Measurement of impurities The nitrogen, sulfur, chlorine, metal components, olefins, conjugated diolefins, and oxygen contained in the waste plastic pyrolysis oil, waste bio-oil, and refined oil were measured using TNS (Total Nitrogen, Sulfur) analyzers (NSX-2100V, TS-100V, TS-100), ion chromatography (Compact IC Pro / AQF-2100H), ICP (Inductively Coupled Plasma) measurement instrument (NexIOn 350S), ED-XRF (Energy Dispersive X-ray Fluorescence), and elemental analyzer (EA 2000 Series), and their contents were calculated.

[0118] [Example 1] A mixed oil was produced by mixing 50 wt% waste plastic pyrolysis oil and 50 wt% waste bio-oil.

[0119] The waste plastic pyrolysis oil was found to contain impurities of 1,100 ppm nitrogen, 80 ppm sulfur, and 250 ppm chlorine using the above measurement method.The waste bio-oil was also found to contain impurities of 60 ppm nitrogen, 10 ppm sulfur, and 10 ppm chlorine using the above measurement method.

[0120] In the hydrotreating reactor, an upper catalyst layer formed of a NiMo / γ-Al2O3 catalyst and a lower catalyst layer formed of a NiMO / γ-ZrO2 catalyst were arranged in order in the feed direction of the mixed oil to be fed as molybdenum sulfide hydrogenation catalysts.

[0121] The hydrotreating reactor was then operated at a liquid hourly space velocity (LHSV) of 2.5 h -1 The mixed oil was hydrotreated at a reaction temperature of 350°C, a hydrogen gas input pressure of 60 bar, and a hydrogen gas mixed oil ratio (GOR) of 1,000.

[0122] The hydrotreated mixed oil produced in the hydrotreating reactor was injected into a separator, which was operated at 25°C to remove ammonia, hydrogen sulfide, water, and hydrogen chloride contained in the hydrotreated mixed oil, and a refined oil was obtained at the bottom of the separator.

[0123] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0124] [Example 2] A refined oil was produced in the same manner as in Example 1, except that a multi-stage catalyst layer was not formed in the hydrotreating reactor, and a single catalyst layer was formed by mixing NiMo / γ-Al2O3 catalyst and NiMo / γ-ZrO2 catalyst.

[0125] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0126] [Example 3] A refined oil was produced in the same manner as in Example 1, except that the reaction temperature of the hydrotreating reactor was 330°C.

[0127] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0128] [Example 4] A refined oil was produced in the same manner as in Example 1, except that the reaction temperature of the hydrotreating reactor was 450°C.

[0129] Next, the refined oil produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0130] [Example 5] A refined oil was produced in the same manner as in Example 1, except that the hydrogen pressure in the hydrotreating reactor was 150 bar.

[0131] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0132] [Example 6] In Example 1, the hydrotreating reactor was operated at a reaction temperature of 390°C and a liquid hourly space velocity (LHSV) of 10 h -1 A refined oil was produced in the same manner except that the above procedure was followed.

[0133] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0134] [Example 7] A refined oil was produced in the same manner as in Example 1, except that the hydrotreating reactor was a GOR 4000.

[0135] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0136] [Example 8] A refined oil was produced in the same manner as in Example 1, except that the mixed oil contained 60 wt % of the waste bio-oil based on the total mass of the mixed oil.

[0137] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0138] [Comparative Example 1] A refined oil was produced in the same manner as in Example 1, except that the catalyst layer of the hydrotreating reactor was formed using only NiMo / γ-Al 2 O 3 catalyst.

[0139] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0140] Comparative Example 2 Refined oil was produced in the same manner as in Example 1, except that NiMo / γ-Al2O3 catalyst was used in the upper catalyst layer and CoMo / γ-Al2O3 catalyst was used in the lower catalyst layer.

[0141] Next, the refined oil thus produced was measured by the above-mentioned measuring method, and the results are shown in Table 2 below.

[0142] [Table 1]

[0143] [Table 2]

[0144] In Table 2, the refined oils produced by the methods of Examples 1 to 8 satisfied the following criteria: nitrogen 40 ppm or less, chlorine 5 ppm or less, sulfur 5 ppm or less, metal compounds 5 ppm or less, olefins 5 wt % or less, and conjugated diolefins 1 wt % or less. In particular, the oxygen content was 0.3 wt % or less, confirming that the impurities in the blended oil were significantly reduced, and preferably, that the impurities were removed to a level that allowed the blended oil to be used in a crude oil refining process.

[0145] In contrast, in Table 2, it was confirmed that the refined oils produced by the methods of Comparative Examples 1 and 2 had a higher impurity content than the refined oils produced by the methods of Examples 1 to 8.

[0146] Therefore, the mixed oil hydrotreating method and the refined oil manufacturing method including the same according to the embodiments of the present disclosure can hydrotreat even waste bio-oil containing a large amount of oxygen impurities due to its excellent reactivity, and the refined oil manufacturing method including the same can produce refined oil with a very low impurity content, in particular, reduced oxygen impurities.

[0147] Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples and may be embodied in various different forms, and those skilled in the art will understand that the present invention may be embodied in other specific forms without changing the technical concept or essential features of the present invention. Therefore, it should be understood that the above-described examples are illustrative in all respects and are not limiting. [Explanation of symbols]

[0148] 1. Mixed oil hydrotreating system 2. Impurity removal system 10 Hydrotreating reactor 20 Mixed oil supply line 30 Catalyst layer 30a Upper catalyst layer 30b Lower catalyst layer 40 Product discharge line 50 Purification Reactor 60 Product supply line 70 Hydrotreated impurities discharge line

Claims

1. A method for hydrotreating a mixed oil containing waste plastic pyrolysis oil and waste bio-oil, in which the mixed oil is hydrotreated with a reaction gas containing hydrogen gas in the presence of a plurality of molybdenum-based hydrogenation catalysts, comprising: The method for hydrotreating a mixed oil, wherein the plurality of molybdenum-based hydrogenation catalysts are two or more molybdenum-based hydrogenation catalysts each containing a different metal support.

2. 2. The method for hydrotreating a mixed oil according to claim 1, wherein the plurality of molybdenum-based hydrogenation catalysts include a molybdenum-based hydrogenation catalyst containing an alumina support and a molybdenum-based hydrogenation catalyst containing a zirconia support.

3. 2. The method for hydrotreating a mixed oil according to claim 1, wherein the hydrotreating of the mixed oil is performed using a multi-stage catalyst layer formed of a molybdenum-based hydrogenation catalyst, each catalyst layer including a different metal support.

4. The multi-stage catalyst layer is made of alumina (Al ２ O ３ A catalyst layer formed of a molybdenum-based hydrogenation catalyst containing a support and zirconia (ZrO ２ 4. The method for hydrotreating a mixed oil according to claim 3, further comprising a catalyst layer formed of a molybdenum-based hydrogenation catalyst comprising a support.

5. The mixed oil hydrotreating method according to claim 1, wherein the mixed oil contains 0.01 to 90% by weight of waste bio-oil based on the total mass.

6. The method for hydrotreating a mixed oil according to claim 1, wherein the waste bio-oil contains 5 wt% or more of oxygen impurities based on the total mass.

7. The method for hydrotreating a mixed oil according to claim 1 , wherein the waste bio-oil has a boiling point of 200° C. or higher.

8. 2. The method for hydrotreating a mixed oil according to claim 1, wherein the reaction temperature for hydrotreating the mixed oil is 330 to 500°C.

9. 2. The method for hydrotreating a mixed oil according to claim 1, wherein the hydrogen gas introduced is 100 bar or less.

10. 2. The method for hydrotreating a mixed oil according to claim 1, wherein the volume ratio of the hydrogen gas and the mixed oil introduced is 300:1 to 3000:

1.

11. The mixed oil hydrotreating method is carried out at a liquid hourly space velocity (LHSV) of 0.1 to 10 h －１ The method for hydrotreating a mixed oil according to claim 1, wherein

12. Producing a product by the mixed oil hydrotreating method according to any one of claims 1 to 11; and removing hydrotreated impurities contained in the product.

13. 13. The method for producing a refined oil according to claim 12, wherein the refined oil contains, based on the total mass, 5 ppm or less of chlorine, 40 ppm or less of nitrogen, 5 ppm or less of sulfur, 5 wt. % or less of olefins, 1 wt. % or less of conjugated diolefins, and 5 ppm or less of metal-based compounds.

14. 13. The method for producing a refined oil according to claim 12, wherein the refined oil contains less than 5% by weight of oxygen based on the total mass of the refined oil.

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