Preparation method of petroleum-based high-softening-point asphalt

Abstract

The preparation method of the petroleum-based high-softening-point asphalt comprises the following steps: an oxidation heat treatment step: introducing oxidizing gas into a raw material containing petroleum-based residual oil for heating; and a reduced pressure heat treatment step of heating the product of the oxidation heat treatment step under reduced pressure conditions. The oil-based residue oil has an aromatization index value of 0.73 or more and a boiling point of 300 DEG C or more when 70 volume% (vol%) is distilled on a distillation curve measured by the ASTM D86 method, and the softening point rise rate of the product of the oxidation heat treatment step is 10-20 DEG C / h when passing through 1 / 3 of the total vacuum heat treatment reaction time in the vacuum heat treatment step, and the softening point rise rate of the product of the oxidation heat treatment step is 10-20 DEG C / h when passing through 1 / 3 of the total vacuum heat treatment reaction time in the vacuum heat treatment step. The softening point of the high softening point asphalt is 150 to 300 DEG C, and the coking value of the high softening point asphalt is 58 to 85 weight percent (wt%).

Description

Technical Field

[0001] The invention relates to a method for preparing petroleum-based high-softening-point asphalt and the high-softening-point asphalt prepared by the method. Background Art

[0002] High softening point asphalt is used as a raw material or precursor for various carbon materials and graphite materials such as carbon fiber, activated carbon, and secondary battery negative electrode materials. In order to prepare high softening point asphalt, there is generally known a method of using coal-based or petroleum-based materials as raw materials through an oxidation process and a heat treatment process.

[0003] It is known that when high softening point asphalt is used as a raw material for secondary battery negative electrode materials, the less quinoline insoluble substances, inorganic impurities such as metals, or heteroatoms such as nitrogen and sulfur contained in the high softening point asphalt, the better the effect of improving battery capacity, life characteristics, and output power characteristics. Petroleum-based raw materials do not actually contain quinoline insoluble substances, so compared with high softening point asphalt prepared using coal-based materials as raw materials, high softening point asphalt prepared using petroleum-based materials as raw materials has the advantage of relatively less quinoline insoluble substances.

[0004] However, in the case of preparing high softening point asphalt using petroleum-based substances as raw materials, the coking value of the prepared high softening point asphalt is lower than the coking value of high softening point asphalt prepared using coal-based substances as raw materials. Therefore, the product quality is unfavorable and there is a problem of low carbonization yield when using high softening point asphalt as raw material.

[0005] In order to improve the carbonization yield of petroleum-based high softening point asphalt, the previous technology for preparing high softening point asphalt using petroleum-based raw materials proposed the use of peroxide compounds (KR2014-0090062A) or halogen compounds (KR1997-0036066A, KR2000-0026341A, KR2015-0069372A). When using the above method to prepare high softening point asphalt, explosive or corrosive chemicals are used in the preparation process, so there are problems of increased process operating costs and increased safety risks.

[0006] The present inventors have thus confirmed that petroleum-based high softening point asphalt can be produced in an economical, efficient and safe manner by controlling the physical properties of petroleum-based raw materials and adjusting the operating conditions in the production process, thereby completing the present invention. Summary of the invention

[0007] Technical issues

[0008] An object of the present invention is to provide a method for preparing a petroleum-based high-softening-point asphalt of excellent quality having an increased coking value by using a raw material containing petroleum-based residual oil.

[0009] The object of the present invention is to provide a method for economically and safely preparing high-quality petroleum-based high-softening point asphalt.

[0010] The purpose of the present invention is not limited to the purpose mentioned above, and other purposes and advantages of the present invention not mentioned can be understood through the following description, and will be more clearly understood through the embodiments of the present invention. Moreover, it is obvious that the purposes and advantages of the present invention can be achieved by the means and combinations thereof shown in the scope of the invention claims.

[0011] Technical Solution

[0012] In order to achieve the above-mentioned purpose, one embodiment of the present invention can provide a method for preparing a petroleum-based high softening point asphalt, comprising: an oxidative heat treatment step, in which an oxidizing gas is charged into a raw material containing petroleum-based residual oil for heating; and a reduced pressure heat treatment step, in which the product of the oxidative heat treatment step is heated under reduced pressure. The aromatization index value of the petroleum-based residual oil is above 0.73, and the boiling point when 70 volume percent (vol%) is distilled on the distillation curve determined by the ASTM D86 method is above 300°C. In the reduced pressure heat treatment step, the softening point rising rate of the product of the oxidative heat treatment step after 1 / 3 of the total reduced pressure heat treatment reaction time is 10-20°C / h, the softening point of the high softening point asphalt is 150-300°C, and the coking value is 58-85 weight percent (wt%).

[0013] The high softening point asphalt may have a softening point of 200 to 300°C.

[0014] The petroleum-based residual oil may include one or more selected from the group consisting of pyrolysis fuel oil (PFO), naphtha cracking bottom oil (NCB), ethylene tar (EBO), fluid catalytic cracking-decant oil (FCC-DO), residual fluid catalytic cracking-decant oil (RFCC-DO) and aromatic extract (AE).

[0015] The feedstock containing petroleum-based residual oil may contain hydrotreated petroleum-based residual oil.

[0016] The process temperature of the oxidation heat treatment step can be 250-400° C., the process time of the oxidation heat treatment step can be 1-20 hours, and the charging flow rate of the oxidizing gas can be 0.01-2 L / min relative to 1 kg of the petroleum-based residual oil.

[0017] The oxidizing gas may include one or more selected from the group consisting of air, oxygen, and ozone.

[0018] The oxidizing gas may further include an inert gas for dilution, and the inert gas for dilution may include one or more selected from the group consisting of nitrogen gas and argon gas.

[0019] The process pressure of the reduced pressure heat treatment step may be 1 to 300 torr, the process heat treatment temperature of the reduced pressure heat treatment step may be 300 to 430° C., and the process time of the reduced pressure heat treatment step may be 4 to 20 hours.

[0020] In the reduced pressure heat treatment step, an inert gas or steam may be mixed, and the inert gas may include one or more selected from the group consisting of nitrogen and argon.

[0021] The preparation method of the petroleum-based high softening point asphalt of the present invention may also include a normal pressure heat treatment step, in which the product of the reduced pressure heat treatment step is heat treated under normal pressure conditions, the process heat treatment temperature of the normal pressure heat treatment step may be 300 to 430°C, and the process time of the normal pressure heat treatment step may be 0.5 to 20 hours.

[0022] Still another embodiment of the present invention provides a petroleum-based high softening point asphalt prepared according to the method for preparing a petroleum-based high softening point asphalt according to one embodiment of the present invention.

[0023] Another embodiment of the present invention provides a negative electrode material for a secondary battery including a petroleum-based high softening point pitch prepared according to the method for preparing a petroleum-based high softening point pitch according to one embodiment of the present invention.

[0024] Effects of the Invention

[0025] The method for preparing petroleum-based high softening point asphalt of the present invention can use petroleum-based raw materials to prepare petroleum-based high softening point asphalt with a significantly increased coking value, thereby preparing petroleum-based high softening point asphalt with high quality and high carbonization yield.

[0026] The preparation method of the petroleum-based high softening point asphalt of the present invention does not use peroxide compounds or halogen compounds, does not have explosion hazards in the preparation process, and can reduce the discharge of environmental pollutants. Therefore, high-quality petroleum-based high softening point asphalt can be prepared safely and economically.

[0027] When a negative electrode material for a secondary battery comprising the petroleum-based high softening point pitch prepared by the method for preparing the petroleum-based high softening point pitch of the present invention is used, the capacity, life and charge and discharge efficiency of the secondary battery can be improved.

[0028] The specific effects of the present invention will be described together with the above-mentioned effects in the following detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a sequence diagram for illustrating a method for preparing a petroleum-based high softening point asphalt according to an example of the present invention.

[0030] Figure 2 The present invention is a simplified process diagram for illustrating a method for preparing a petroleum-based high softening point asphalt according to an example of the present invention.

[0031] Best Mode for Carrying Out the Invention

[0032] The above-mentioned purposes, features and advantages will be described in detail in the following content, and ordinary technicians in the technical field to which the present invention belongs can easily implement the technical ideas of the present invention. In the process of describing the present invention, if the detailed description of the known technology related to the present invention is judged to be likely to unnecessarily confuse the gist of the present invention, its detailed description will be omitted. The terms described below are terms recorded after considering the functions and effects in the present invention, and the meaning of each term should be interpreted based on the overall content of this specification.

[0033] In this specification, when it is mentioned that a certain structural element is located on other structural elements, it means that it can be directly formed on other structural elements or a third structural element can be interposed between them. In addition, in the drawings, the thickness of the structural elements may be exaggerated for the effective description of the technical content. In the entire specification, parts represented by the same reference numerals represent the same structural elements.

[0034] In various embodiments of the present specification, the terms "first", "second", "third", etc. are used to describe various structural elements, but these structural elements are not limited by these terms. These terms are only used to distinguish a certain structural element from other structural elements.

[0035] The terms used in this specification are used to illustrate the embodiments, rather than to limit the present invention. In this specification, unless otherwise specified, a sentence in the singular includes the plural form. The descriptions such as "comprising" and "containing" used in this specification do not exclude the existence of the mentioned structural element or the addition of one or more other structural elements.

[0036] Hereinafter, the present invention will be described in detail.

[0037] One embodiment of the present invention provides a method for preparing petroleum-based high softening point asphalt.

[0038] Reference Figure 1 and Figure 2 The method for preparing a petroleum-based high softening point asphalt according to an embodiment of the present invention may include: an oxidative heat treatment step, in which an oxidizing gas is introduced into a raw material containing petroleum-based residual oil for heating; and a reduced pressure heat treatment step, in which a product of the oxidative heat treatment step is heated under reduced pressure conditions.

[0039] Oxidation heat treatment step S1

[0040] Preferably, the aromatization index value of the petroleum-based residual oil contained in the raw material of the present invention may be greater than 0.73, greater than 0.75, or greater than 0.80. If a petroleum-based residual oil with an aromatization index value less than 0.73 is used as a raw material, the reactivity is rapid and the amount of oil discharged by decomposition is large, and the growth of the mesophase during carbonization is difficult, resulting in the problem of not being able to obtain high-quality high-softening point asphalt.

[0041] Furthermore, preferably, the boiling point of the petroleum-based residual oil when 70% of the distillation is distilled on the distillation curve determined by the standard ASTM D86 method can be above 300°C, above 320°C, or above 330°C. When a raw material having a boiling point of less than 300°C when 70% of the distillation is distilled on the distillation curve is used, not only the yield of the preparation of the high softening point asphalt is low, it is difficult to adjust the reaction temperature in the reduced pressure heat treatment process, but also the product quality is reduced due to the lack of high molecular weight substances in the molecular weight distribution of the prepared high softening point asphalt.

[0042] Generally, petroleum-based residual oil has a large molecular weight and a high boiling point compared to light oil, and is therefore suitable for use as a raw material for carbon materials. However, compared to carbon materials prepared using coal-based residual oil, carbon materials prepared using petroleum-based residual oil have a low carbonization yield and a low coking value, which may cause a decrease in the quality of the final prepared product.

[0043] In order to solve the technical problem, the inventors focused on using petroleum-based residual oil with controlled physical properties of aromatization index and distillation curve as raw material, and then by adjusting the operating conditions of reduced pressure heat treatment, it is possible to prepare high softening point asphalt with excellent physical properties having a high coking value and a softening point adjusted to 150-300°C even when using petroleum-based residual oil as raw material, thereby completing the present invention.

[0044] The petroleum-based residual oil that can be used as a raw material is not particularly limited as long as it is used in the technical field to which the present invention belongs. For example, the petroleum-based residual oil can include one or more selected from the group consisting of cracking fuel oil, naphtha cracking tower bottom oil, ethylene tar, fluid catalytic cracking clarified oil, heavy oil catalytic cracking clarified oil and aromatic extract.

[0045] Furthermore, the petroleum-based residual oil that has been hydrotreated may be used as a raw material. Therefore, the raw material containing the petroleum-based residual oil may include petroleum-based residual oil and hydrotreated petroleum-based residual oil.

[0046] The process temperature of the oxidative heat treatment step S1 is the temperature of the reactants in the oxidative heat treatment step, preferably, it can be 250-400°C, it can be 300-400°C, it can be 300-350°C. If the temperature of the reactants in the oxidative heat treatment process is less than 250°C, the molecular weight of the petroleum-based residual oil is not sufficiently increased, and the yield of the high softening point asphalt as the final product is reduced. In addition, if the temperature of the reactants in the oxidative heat treatment process is greater than 400°C, coking will occur due to the sharp increase in the content of quinoline insolubles in the reactants of the oxidative heat treatment process. In addition, if the petroleum-based residual oil is heat-treated under high temperature conditions or oxidation reaction conditions, resulting in excessive polymerization of aromatic compounds, the petroleum-based residual oil will also be converted into insoluble substances.

[0047] Preferably, the process time of the oxidative heat treatment step S1 can be 1 to 20 hours, can be 5 to 20 hours, can be 10 to 15 hours, but is not limited thereto. If the process time of the oxidative heat treatment step is less than 1 hour, it will be difficult for the oxidation reaction to fully occur. In addition, if the process time of the oxidative heat treatment step is greater than 20 hours, the physical properties of the high softening point asphalt as the final product will be deteriorated due to inducing excessive polymerization reaction. In particular, if the oxidation reaction is excessively carried out, the oxygen content of the prepared high softening point asphalt will be increased. This will reduce the performance of the secondary battery when it is subsequently used as a raw material for the negative electrode material of a secondary battery.

[0048] In the oxidative heat treatment step S1, preselectively, the charging flow rate of the oxidizing gas can be 0.01 to 2 L / min, 0.3 to 2 L / min, 0.5 to 2 L / min, or 0.3 to 1 L / min relative to 1 kg of the petroleum-based residual oil. If the flow rate of the oxidizing gas is less than 0.01 L / min relative to 1 kg of the petroleum-based residual oil, the yield and quality of the product will be reduced due to insufficient cross-linking reaction. On the other hand, if the flow rate of the oxidizing gas is greater than 2 L / min relative to 1 kg of the petroleum-based residual oil, the excessive amount of the oxidizing gas will cause a sharp increase in the content of toluene insolubles as a heavy component and an increase in the content of quinoline insolubles (QI).

[0049] In the oxidation heat treatment step S1, the oxidizing gas may include one or more selected from the group consisting of air, oxygen and ozone. For example, the oxidizing gas may directly use air in the atmosphere. In addition, the oxidizing gas may be diluted with an inert gas for use. Therefore, the oxidizing gas may also include an inert gas for dilution. The inert gas for dilution may include one or more selected from the group consisting of nitrogen and argon.

[0050] Generally, in order to increase the softening point of high-softening-point asphalt as the final product, a catalyst can be used under high pressure conditions, and in order to reduce the quinoline insoluble (QI) content in the high-softening-point asphalt, a peroxide (peroixide) compound can be mixed with an oxidizing gas for use.

[0051] However, if the catalyst is used under high pressure conditions, not only expensive high pressure vessels are required, but also an additional process for removing the catalyst is required, which increases the cost of producing high softening point asphalt.

[0052] Furthermore, if peroxide compounds are added to the oxidizing gas, there will be an explosion hazard during the preparation process due to the high reactivity of peroxide compounds, which will increase the cost of peroxide compounds, the cost of hazardous materials management and the cost of wastewater treatment. Therefore, the economic efficiency of large-scale production of high softening point asphalt will be reduced.

[0053] According to the present invention, the molecular weight of petroleum-based residual oil can be increased by the oxidation heat treatment process, thereby improving the yield of high softening point asphalt as the final product. In particular, the oxidation heat treatment process does not require high pressure conditions and does not use a catalyst, and can produce economical and high-quality petroleum-based high softening point asphalt.

[0054] Furthermore, according to the present invention, before or during the oxidation heat treatment process, peroxide compounds may not be used as the oxidation reactor. Not using the peroxide compounds has the advantage of making the preparation process economical and preventing explosion hazards in the preparation process.

[0055] On the other hand, the oxidative heat-treated petroleum-based residual oil can be prepared into petroleum-based asphalt through the oxidative heat treatment step S1. Therefore, the "petroleum-based asphalt" in this specification can refer to the petroleum-based residual oil oxidatively heat-treated through the oxidative heat treatment step S1.

[0056] Reduced pressure heat treatment step S2

[0057] A reduced pressure heat treatment step S2 may be performed to heat the petroleum-based asphalt, which is a product of the oxidative heat treatment step S1, under reduced pressure. The reduced pressure heat treatment step may be performed in a reduced pressure heat treatment device.

[0058] In order to control the softening point rising rate of the initial reactants, the reduced pressure heat treatment device for performing the reduced pressure heat treatment step S2 may include a sampling device for the reactants, a device for adjusting the outflow of oil flowing out in the form of waste gas (Off Gas) of the reactor, and a device for adjusting the internal pressure of the reactor.

[0059] The heavy oil of the petroleum-based asphalt can be removed by the reduced pressure heat treatment step S2, the softening point can be increased, and the content of toluene insoluble matter can be increased, thereby increasing the carbonization yield of the asphalt.

[0060] If the petroleum-based asphalt is subjected to a normal pressure heat treatment step or a pressure heat treatment step instead of a reduced pressure heat treatment step unlike the present invention, it will be difficult to remove the heavy oil and the softening point of the asphalt will not increase.

[0061] In the reduced pressure heat treatment step S2, preferably, the softening point rising rate of the product (petroleum-based asphalt) of the oxidative heat treatment step after 1 / 3 of the total reduced pressure heat treatment reaction time can be 10-20°C / h, 12-20°C / h, 14-20°C / h, 14-18°C / h, or 14-16°C / h.

[0062] If the softening point rising rate is below 10°C / h, the undischarged heavy oil acts as a solvent to inhibit the generation of toluene-insoluble matter (TI) through thermal polymerization of high-softening point asphalt, which ultimately reduces the coking value of high-softening point asphalt. In addition, since the oil is not discharged in the initial stage of the reaction, the oil is polymerized under the action of heat. When the reaction proceeds to the second half, the oil with a larger molecular weight becomes more difficult to remove, making it difficult to increase the softening point of the asphalt.

[0063] On the other hand, if the softening point increase rate is above 20°C / h, the molecular weight of the high softening point asphalt cannot be sufficiently increased due to the shortened reduced pressure heat treatment reaction time, thereby causing the problem of reduced product quality of the high softening point asphalt.

[0064] Preferably, the process pressure of the reduced pressure heat treatment step S2 can be 1 to 300 Torr, 1 to 100 Torr, 1 to 200 Torr, 50 to 250 Torr, 80 to 100 Torr, or 80 to 150 Torr, but is not limited thereto.

[0065] Preferably, the heat treatment temperature of the reduced pressure heat treatment step S2 can be 300-430°C, can be 200-400°C, or can be 300-350°C. If the heat treatment temperature of the reduced pressure heat treatment process is less than 300°C, it will be difficult to remove the heavy oil, and it will be difficult to prepare high-quality high-softening point asphalt due to the reduced generation of toluene insolubles. In addition, there will be limitations in increasing the softening point of petroleum-based asphalt due to insufficient removal of the heavy oil in the asphalt. If the heat treatment temperature of the reduced pressure heat treatment process is greater than 430°C, coke will be formed due to the coking phenomenon of the petroleum-based asphalt, and there will be a problem of a sharp increase in the content of quinoline insolubles (QI).

[0066] Preferably, the process time of the reduced pressure heat treatment step S2 can be 1 to 20 hours, can be 4 to 20 hours, can be 5 to 15 hours, can be 5 to 12 hours. If the reduced pressure heat treatment process is carried out for less than 1 hour, the heavy oil cannot be fully removed, and it will be difficult to prepare asphalt with a high softening point. In addition, due to insufficient time for the thermal polymerization reaction, toluene insolubles cannot be fully generated, and low-quality high-softening point asphalt with a low carbonization yield will be prepared. If the reduced pressure heat treatment process is carried out for more than 20 hours, toluene insolubles will be excessively generated due to excessive polymerization reaction, and the operating cost of the process and the preparation cost of the product will increase due to the increase in process time.

[0067] In the reduced pressure heat treatment step S2, an inert gas or steam may be mixed, and the inert gas may include one or more selected from the group consisting of nitrogen and argon, thereby more effectively removing the heavy oil from the petroleum-based asphalt. In particular, when the inert gas or steam is heated and then charged, the heavy oil can be more effectively removed.

[0068] For example, the flow rate of the inert gas or steam may be 0.01 to 2.0 L / min relative to 1 kg of the petroleum-based asphalt, but is not limited thereto.

[0069] The reduced pressure heat treatment step S2 of the present invention is characterized in that no oxidizing gas is charged. If an oxidizing gas is charged in the reduced pressure heat treatment step S2 unlike the present invention, there is a problem that quinoline insolubles are rapidly formed due to the oxidation reaction at high temperature.

[0070] Normal pressure heat treatment step S3

[0071] The method for preparing petroleum-based high softening point asphalt of the present invention can selectively perform a normal pressure heat treatment step S3 on the petroleum-based asphalt after the reduced pressure heat treatment step S2. The normal pressure heat treatment step S3 can increase the toluene insoluble content of the petroleum-based high softening point asphalt.

[0072] For example, preferably, the process heat treatment temperature of the atmospheric pressure heat treatment step S3 can be 300-430° C., but is not limited thereto. If the heat treatment temperature of the atmospheric pressure heat treatment step S3 is less than 300° C., it will be difficult to generate heavy toluene insolubles, and if the heat treatment temperature of the atmospheric pressure heat treatment step is greater than 430° C., coke will be formed due to the coking phenomenon of petroleum-based asphalt, and the content of quinoline insolubles will increase sharply.

[0073] For example, the process of the normal pressure heat treatment step S3 can be carried out for 0.5 to 20 hours. On the contrary, if the process of the normal pressure heat treatment step S3 is less than 0.5 hours (= 30 minutes), the toluene insolubles cannot be fully generated due to the short heat treatment reaction time. If the process of the normal pressure heat treatment step S3 is greater than 20 hours, the operating cost of the process and the preparation cost of the product will increase due to the increase in the operating time.

[0074] High softening point asphalt

[0075] Preferably, the softening point of the petroleum-based high softening point asphalt prepared by the method for preparing the petroleum-based high softening point asphalt of the present invention may be 150 to 300°C, or 200 to 300°C.

[0076] The coking value of pitch is a physical property that affects the yield of conversion into carbon materials when the pitch is carbonized, and is comprehensively affected by the molecular weight, aromatization index, molecular structure, etc. of the pitch. Relative to the total weight of the petroleum-based high softening point pitch, the coking value of the high softening point pitch of the present invention can be 50 weight percent or more, can be 58 weight percent or more, and preferably has a range of 58 weight percent to 85%. If the coking value of the high softening point pitch is less than 58 weight percent, more volatile substances are produced when the high softening point pitch is carbonized and the yield of conversion into carbon materials is low, so there is a problem that it cannot be used as a raw material for carbon materials. On the other hand, if the coking value of the high softening point pitch is greater than 85 weight percent, the high softening point pitch contains almost no volatile substances, but will be composed of aromatized hydrocarbons with large molecular weight, which will make it difficult to process the high softening point pitch or difficult to evenly coat it on the negative electrode material of the secondary battery.

[0077] Therefore, the petroleum-based high softening point asphalt prepared by the method for preparing the petroleum-based high softening point asphalt of the present invention has a high softening point and a significantly increased coking value.

[0078] According to the present invention, petroleum-based residual oil can be used as a raw material to prepare a petroleum-based high softening point asphalt by performing an oxidative heat treatment step S1 and a reduced pressure heat treatment step S2. The petroleum-based high softening point asphalt can be used as a raw material for a carbon material or a graphite material, or as a precursor of a carbon material or a graphite material. When used as a raw material for various carbon materials and graphite materials, it can be used as an excellent precursor with a high carbonization yield. For example, the petroleum-based high softening point asphalt can be used as a precursor of carbon fiber through a carbonization process and a graphitization process.

[0079] As an embodiment, when the petroleum-based high softening point pitch of the present invention is used as a precursor material for carbon fibers, the properties of the high softening point and carbonization yield of the petroleum-based high softening point pitch, as well as the high coking value and low impurity content, can be exhibited. Therefore, the physical properties of the carbon fibers prepared using the petroleum-based high softening point pitch, such as tensile strength and tensile modulus, will be excellent. Furthermore, as an embodiment, the specific surface area and mechanical strength of the activated carbon prepared using the petroleum-based high softening point pitch will be excellent.

[0080] As one embodiment, the petroleum-based high softening point pitch of the present invention can be used as a binder material or a coating material for negative electrode materials (eg, natural graphite negative electrode materials, artificial graphite negative electrode materials, etc.).

[0081] As an embodiment, petroleum-based high softening point asphalt can be used as a carbon-based negative electrode material by subjecting it to a carbonization process, and can be used as a precursor of carbon fibers by subjecting it to a carbonization process and a graphitization process.

[0082] As an embodiment, when the petroleum-based high softening point asphalt prepared by the method for preparing the petroleum-based high softening point asphalt of the present invention is used as a raw material for a negative electrode material of a secondary battery, the performance of the prepared secondary battery can be improved. DETAILED DESCRIPTION

[0083] The present invention will be described in more detail below by way of examples. However, the following examples are only for illustrating the present invention, and the content of the present invention is not limited to the following examples.

[0084] Example 1

[0085] As petroleum-based residual oil, a pyrolysis fuel oil (PFO) having an aromatization index of 0.76 and a boiling point of 320° C. when 70% of the distillation curve is distilled according to the standard ASTM D86 method is used as a raw material, and an oxidative heat treatment step of heating by charging an oxidizing gas is performed in an oxidation reactor. Air is used as the oxidizing gas, and is charged at a flow rate of 0.5 L / min relative to 1 kg of the pyrolysis fuel oil. The temperature of the reactant in the oxidative heat treatment step is 320° C., and the oxidative heat treatment process is performed for 6 hours.

[0086] Then, the pressure was reduced to 80 Torr, and a reduced pressure heat treatment step was performed at 350°C for 15 hours to prepare a petroleum-based high softening point asphalt. In the reduced pressure heat treatment step, the softening point increase rate of the reactant in the initial 5 hours was adjusted to 14°C / h.

[0087] The softening point of the prepared petroleum-based high-softening-point asphalt is 242° C., and the coking value is 68 weight percent relative to the total weight of the petroleum-based high-softening-point asphalt.

[0088] Example 2

[0089] As petroleum-based residual oil, a pyrolysis fuel oil having an aromatization index of 0.80 and a boiling point of 340°C when 70% of the distillation curve measured by the standard ASTM D86 method is used as a raw material, and an oxidative heat treatment step of heating by charging an oxidizing gas is performed in an oxidation reactor. Air is used as the oxidizing gas, and is charged at a flow rate of 0.3 L / min relative to 1 kg of the pyrolysis fuel oil. The temperature of the reactant in the oxidative heat treatment step is 350°C, and the oxidative heat treatment process is performed for 10 hours.

[0090] Then, the pressure was reduced to 150 Torr, and a reduced pressure heat treatment step was performed at 370°C for 12 hours to prepare a petroleum-based high softening point asphalt. In the reduced pressure heat treatment step, the softening point increase rate of the reactant in the initial 4 hours was adjusted to 16°C / h.

[0091] The softening point of the prepared petroleum-based high-softening-point asphalt is 258° C., and the coking value is 74 weight percent relative to the total weight of the petroleum-based high-softening-point asphalt.

[0092] Comparative Example 1

[0093] As petroleum-based residual oil, a pyrolysis fuel oil having an aromatization index of 0.68 and a boiling point of 310°C when 70% of the distillation curve measured by the standard ASTM D86 method is used as a raw material, and an oxidative heat treatment step of heating by charging an oxidizing gas is performed in an oxidation reactor. Air is used as the oxidizing gas, and is charged at a flow rate of 0.3 L / min relative to 1 kg of the pyrolysis fuel oil. The temperature of the reactant in the oxidative heat treatment step is 350°C, and the oxidative heat treatment process is performed for 10 hours.

[0094] Then, the pressure was reduced to 150 Torr, and a reduced pressure heat treatment step was performed at 370°C for 12 hours to prepare a petroleum-based high softening point asphalt. In the reduced pressure heat treatment step, the softening point increase rate of the reactant in the initial 4 hours was adjusted to 16°C / h.

[0095] The softening point of the prepared petroleum-based high-softening-point asphalt is 245° C., and the coking value is 56 weight percent relative to the total weight of the petroleum-based high-softening-point asphalt.

[0096] Comparative Example 2

[0097] As petroleum-based residual oil, a pyrolysis fuel oil having an aromatization index of 0.76 and a boiling point of 280°C when 70% of the distillation curve measured by the standard ASTM D86 method is distilled is used as a raw material, and an oxidative heat treatment step of heating by charging an oxidizing gas is performed in an oxidation reactor. Air is used as the oxidizing gas, and is charged at a flow rate of 0.5 L / min relative to 1 kg of the pyrolysis fuel oil. The temperature of the reactant in the oxidative heat treatment step is 320°C, and the oxidative heat treatment process is performed for 6 hours.

[0098] Then, the pressure was reduced to 80 Torr, and a reduced pressure heat treatment step was performed at 350°C for 15 hours to prepare a petroleum-based high softening point asphalt. In the reduced pressure heat treatment step, the softening point increase rate of the reactant in the initial 5 hours was adjusted to 14°C / h.

[0099] The softening point of the prepared petroleum-based high-softening-point asphalt is 244° C., and the coking value is 55 weight percent relative to the total weight of the petroleum-based high-softening-point asphalt.

[0100] Comparative Example 3

[0101] The process was carried out in the same manner as in Example 1, except that the rate of increase in the softening point of the reactant in the initial 5 hours of the reduced pressure heat treatment step was adjusted to 24° C. / h instead of 14° C. / h.

[0102] The softening point of the prepared petroleum-based high-softening-point asphalt is 238° C., and the coking value is 53 weight percent relative to the total weight of the petroleum-based high-softening-point asphalt.

[0103] The aromatization index of the petroleum-based residual oil in Examples 1 to 2 and Comparative Examples 1 to 3, the boiling point at 70% distillation on the distillation curve measured according to the standard ASTM D86 method, the initial softening point rising rate in the reduced pressure heat treatment step, and the physical properties of the prepared petroleum-based high softening point asphalt are shown in the following Table 1.

[0104] Table 1

[0105]

[0106] With reference to Table 1, it can be confirmed that the petroleum-based high softening point asphalts of Examples 1 and 2 have a high softening point of 200° C. or more and a high coking value of 58 weight percent or more.

[0107] On the contrary, the comparative example 1 uses thermal cracking fuel oil with an aromatization index of 0.68 and a boiling point of 310°C at 70% distillation on the distillation curve measured by the standard ASTM D86 method as the raw material. The results show that as the aromatization index of the petroleum-based raw material decreases, the coking value of the prepared petroleum-based high softening point asphalt also decreases.

[0108] Furthermore, Comparative Example 2 used a raw material having the same aromatization index value as Example 1, but used a thermal cracking fuel oil having a low boiling point when 70% was distilled on the distillation curve measured according to the standard ASTM D86 method as the starting raw material. It can be confirmed that the coking value of the prepared petroleum-based high softening point asphalt is low.

[0109] In addition, Comparative Example 3 used the same petroleum-based residual oil as in Example 1 as a raw material, and carried out an oxidative heat treatment reaction process under the same operating conditions. However, in the reduced pressure heat treatment process, the softening point rise rate of the initial reactant was increased to 24°C / h for preparation, and it was confirmed that the coking value of the prepared petroleum-based high softening point asphalt was low.

[0110] The above is described in more detail with reference to the embodiments and drawings of this specification, but this specification is not limited to the embodiments and drawings, and various modifications can be implemented without departing from the technical ideas of this specification. Therefore, the embodiments disclosed in this specification are not intended to limit the technical ideas of the present invention, but are used to illustrate the present invention, and the scope of the technical ideas of the present invention is not limited to these embodiments. Therefore, no matter from which aspect, the embodiments described above should be interpreted as examples rather than limitations. The protection scope of this specification and the present invention should be interpreted in accordance with the protection scope of the invention claims, and all technical ideas within the same scope should be interpreted as included in the scope of rights of this specification and the present invention.

Claims

1. A method for preparing petroleum-based high softening point asphalt, characterized in that: include: an oxidative heat treatment step of heating the feedstock containing petroleum-based residual oil by injecting an oxidizing gas; and a reduced pressure heat treatment step of heating the product of the oxidative heat treatment step under reduced pressure, The petroleum-based residual oil has an aromatization index value of 0.73 or more, and a boiling point of 300° C. or more when 70% by volume is distilled on a distillation curve measured by ASTM D86 method. In the reduced pressure heat treatment step, the softening point increase rate of the product of the oxidation heat treatment step after 1 / 3 of the total reduced pressure heat treatment reaction time is 10 to 20°C / h, The high softening point asphalt has a softening point of 150 to 300° C. and a coking value of 58 to 85 weight percent.

2. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The high softening point asphalt has a softening point of 200 to 300°C.

3. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The petroleum-based residual oil includes at least one selected from the group consisting of cracked fuel oil, naphtha cracked bottom oil, ethylene tar, fluidized catalytic cracking clarified oil, heavy oil catalytic cracking clarified oil and aromatic extracts.

4. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The feedstock containing petroleum-based residual oil includes hydrogenated petroleum-based residual oil.

5. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The process temperature of the oxidation heat treatment step is 250-400°C. The process time of the oxidation heat treatment step is 1 to 20 hours. The injection flow rate of the oxidizing gas is 0.01 to 2 L / min relative to 1 kg of the petroleum-based residual oil.

6. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The oxidizing gas includes one or more selected from the group consisting of air, oxygen, and ozone.

7. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The oxidizing gas further includes an inert gas for dilution. The dilution inert gas includes at least one selected from the group consisting of nitrogen gas and argon gas.

8. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The process pressure of the reduced pressure heat treatment step is 1 to 300 Torr, The heat treatment temperature of the reduced pressure heat treatment step is 300-430°C. The process time of the reduced pressure heat treatment step is 4 to 20 hours.

9. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: In the reduced pressure heat treatment step, an inert gas or steam is mixed in. The inert gas includes at least one selected from the group consisting of nitrogen gas and argon gas.

10. The method for preparing petroleum-based high softening point asphalt according to claim 1, characterized in that: The method further comprises a normal pressure heat treatment step, wherein the product of the reduced pressure heat treatment step is heat treated under normal pressure. The process heat treatment temperature of the normal pressure heat treatment step is 300-430°C. The process time of the normal pressure heat treatment step is 0.5 to 20 hours.

11. A petroleum-based high softening point asphalt, characterized in that: Prepared according to the method for preparing petroleum-based high softening point asphalt according to any one of claims 1 to 10.

12. A negative electrode material for a secondary battery, characterized in that: A petroleum-based high softening point asphalt prepared by the method for preparing a petroleum-based high softening point asphalt according to any one of claims 1 to 10.

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