JPWO2007074939A1 - Coking coal for power storage carbon materials - Google Patents

Abstract

When washing activated carbon obtained by activating alkali, it is possible to reduce the residual alkali content in the activated carbon because the washing liquid is easy to enter and exit, and as raw material coal that gives activated carbon that can simplify the washing operation, or for needle coke production The raw carbon has a structure in which the ratio between the crystallite size and the lattice constant of graphitized material when graphitized at 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. Coking coal is provided.

Description

  The present invention relates to a raw material carbon for power storage carbon material and needle coke. In particular, the present invention relates to a raw material coal that provides activated carbon from which residual alkali metals can be easily removed as activated carbon for an electric double layer capacitor electrode. The present invention also relates to raw coal suitable for needle coke.

In recent years, carbon materials have been widely used in the field of electric power. As such a carbon material for power storage, for example, activated carbon having a relatively large surface area is used for an electrode of an electric double layer capacitor, and coke having a relatively small surface area is used as a negative electrode of a lithium ion secondary battery. Yes. In particular, electric double layer capacitors are attracting attention as backup power supplies, auxiliary power supplies, etc., and development focusing on the performance of activated carbon as an electrode for electric double layer capacitors has been widely made. Electric double layer capacitors using activated carbon as a polarizable electrode are excellent in electrostatic capacity, so that demand for electric device electrode applications and the like is growing rapidly with the development of the electronics field. Recently, in addition to the miniaturization of conventional memory backup power supplies, development of large-capacity products that can be used for auxiliary power supplies such as motors has been carried out.
As a method for producing these activated carbons, the carbonaceous material is subjected to a gas activation treatment or a chemical activation treatment, for example, an alkali activation treatment using an alkali metal hydroxide as an activation aid, and then an alkali metal or heavy metal from the activation treatment product. In order to remove water, neutralization washing with a strong acid such as hydrochloric acid, nitric acid or sulfuric acid is generally performed.
With the demand for higher performance of electric double layer capacitors, there has been a need to further reduce the residual alkali metal in activated carbon for electric double layer capacitor electrodes. However, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-123462), even if the alkali metal can be removed up to a certain level by repeated washing with water and pickling, it is difficult to remove it further. . For this reason, an electric double layer capacitor using a carbon material after alkali activation has an initial capacitor capacity, but has a problem of deterioration over time such that the capacitor capacity greatly decreases when used for a long time.
On the other hand, from the viewpoint of the cleaning operation, the cleaning operation is as simple as possible, that is, it is desirable that the number of times of cleaning is as small as possible in terms of cost. In Patent Document 2 (International Publication No. 2004-011371 pamphlet), an easily activated graphitized carbonaceous material is subjected to an alkali activation treatment, and the obtained activation treatment product is used as hot water, carbonated water, hot hydrochloric acid, aqueous ammonia, hot hydrochloric acid. In addition, although it is described that activated carbon is obtained by washing in order of hot water, since the washing operation is complicated, development of activated carbon having a structure in which residual alkali metal is easily removed has been strongly desired.
On the other hand, needle coke used for the aggregate of graphite electrodes for electric steelmaking is generally manufactured using petroleum heavy oil or coal tar as a raw material. In the process of producing a graphite electrode, first, coke grains and a binder pitch are blended at a predetermined ratio, heat-combined, and then extruded to produce a raw electrode. The raw electrode is fired, graphitized, and then processed to obtain a graphite electrode product.
Since the graphite electrode is used under severe conditions such as a high temperature atmosphere, it is desired that the coefficient of thermal expansion (CTE) is low. That is, the smaller the coefficient of thermal expansion, the smaller the electrode consumption during electric steelmaking, and the cost of electric steelmaking can be reduced.
In addition, the graphitization is a process of heat treatment at about 3000 ° C., and a method using a direct current type furnace (LWG furnace) is common, but when graphitization is performed using an LWG furnace, the rate of temperature rise Therefore, the gas generation speed increases, and an abnormal expansion phenomenon called puffing is likely to occur. When puffing occurs, the electrode is reduced in density, and in some cases, the electrode is damaged.
Therefore, methods for controlling the coefficient of thermal expansion and the quality of puffing during the manufacture of needle coke have been studied, and various methods have been proposed. For example, in Patent Document 3 (Japanese Patent Laid-Open No. 5-105881), an oligomer whose polymerization degree is adjusted is added to a de-QI pitch from which a quinoline insoluble matter is substantially removed from a coal tar-based raw material, and a delayed coking method is used as it is. A method of coking is disclosed. Patent Document 4 (JP-A-5-163491) describes a range in which coal tar heavy oil and petroleum heavy oil have a nitrogen content of 1.0 wt% or less and a sulfur content of 1.4 wt% or less. The raw oil is prepared by mixing the raw oil into a delayed coker, and the raw coke is calcined in the temperature range of 700 to 900 ° C. and cooled once. After that, the method of calcination again in the temperature range of 1200 to 1600 ° C. is disclosed. In Patent Document 5 (Japanese Patent Laid-Open No. 5-202362), when producing coal tar by rapid pyrolysis of coal, the pyrolysis temperature in the reactor is kept at 750 ° C. or higher, and A method is disclosed in which a liquid product is obtained by setting the residence time in the reactor to 5 seconds or less, and the liquid product or pitch contained therein is carbonized. Patent Document 6 (Japanese Patent Application Laid-Open No. 7-3267) discloses a raw material oil obtained by mixing a petroleum heavy oil alone or a mixture of a coal tar heavy oil from which the quinoline insoluble component has been previously removed with the petroleum heavy oil. As a petroleum-based heavy oil, a method using a pre-adjusted so that the content of particles such as ash is in the range of 0.05 wt% to 1 wt% is disclosed. ing.
However, even with the methods described in Patent Documents 3 to 6, the effect of reducing the thermal expansion coefficient or suppressing puffing is not necessarily sufficient, and the quality of the obtained coke is as an aggregate of graphite electrodes for electric steelmaking. The actual situation is that the required level has not yet been reached.

The inventors of the present invention have activated carbon obtained by alkali activation of raw coal having a specific structure, which makes it easy for the cleaning liquid to enter and exit during cleaning, and as a result, can reduce the residual alkali content in the activated carbon, It was found that the washing operation can be simplified.
Furthermore, the present inventors have found that needle coke obtained by further calcining such raw coal has a sufficiently small thermal expansion coefficient and puffing is sufficiently suppressed.
In the present invention, “coking coal” refers to a carbide used as a raw material for activated carbon or needle coke, obtained by coking a raw oil such as heavy oil or residual oil.
That is, the present invention has a structure in which the ratio of the crystallite size and the lattice constant of graphitized material when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. It relates to coking coal characterized by having.
Further, the present invention provides an initial boiling point of 200 ° C. or higher obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or higher under a condition of a total pressure of 16 MPa or higher so that the hydrocracking rate is 30% or lower. And a second heavy oil having an initial boiling point of 150 ° C. or higher and a sulfur content of 0.5% by mass or less, obtained by fluid catalytic cracking of hydrocarbon oil. The present invention relates to a raw material oil composition for producing the raw coal.
Moreover, this invention relates to the manufacturing method of the said raw coal characterized by coking the said raw material oil composition at 300-800 kPa and 400-600 degreeC.
The present invention also relates to activated carbon obtained by activating the raw coal or the raw coal heat-treated product obtained by heat-treating the raw coal at 550 to 900 ° C. under normal pressure with an alkali metal hydroxide.
The present invention also relates to an electric double layer capacitor using the activated carbon as an electrode material.
Furthermore, this invention relates to the needle coke obtained by calcining the said raw coal at 800-1600 degreeC.
[The invention's effect]
The activated carbon obtained by alkali activation of the raw coal of the present invention is easy for the cleaning solution to enter and exit, and as a result, the amount of residual alkali metal is reduced even in the same cleaning operation, so the cycle of the electric double layer capacitor using it as an electrode material Improved characteristics. Moreover, since the washing operation is simplified, the activated carbon can be manufactured at a lower cost, and its industrial value is extremely large. Further, the needle coke obtained by further calcining the raw coal of the present invention has a sufficiently small coefficient of thermal expansion, and puffing is sufficiently suppressed.

Hereinafter, the present invention will be described in detail.
In the raw coal of the present invention, the ratio of the crystallite size and the lattice constant of the graphitized product when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. Gives structure. When the ratio of the crystallite size to the lattice constant on the 002 plane exceeds 360, or the ratio of the crystallite size to the lattice constant on the 110 plane exceeds 1500, the ratio of the edge plane to the crystallite of the raw coal is For this reason, it is considered that the amount of potassium remaining in the activated carbon increases because the cleaning solution cannot enter the crystallites through the edge surface and the cleaning effect is reduced.
Here, the interlayer distance d ₀₀₂ (lattice constant) of the microcrystalline carbon and the crystallite size Lc ₀₀₂ of the microcrystalline carbon were determined by the Japan Society for the Promotion of Science 117th Committee, “Lattice constant and crystallite of artificial graphite” In accordance with the “size measurement method”, the X-ray diffraction method is used as follows.
That is, sample powder (one obtained by graphitizing raw coal at 2800 ° C.) is filled in a sample holder, and an X-ray diffraction pattern is obtained using CuKα rays monochromatized by a graphite monochromator as a radiation source. The peak position of the diffraction pattern is obtained by the centroid method (a method of obtaining the centroid position of the diffraction line and obtaining the peak position using the corresponding 2θ value), and the diffraction peak of the (111) plane of the high-purity silicon powder for standard materials. Use to correct. Then, the wavelength of the CuKα ray is set to 0.15418 nm, and the interlayer distance d ₀₀₂ of microcrystalline carbon is calculated by the Bragg formula expressed by the following formula (1).
d ₀₀₂ = λ / (2 sin θ) (1)
The presence or absence of formation of the graphite structure in the sample can be confirmed, for example, by having a clear peak at 2θ of about 25 ° in the powder X-ray diffraction pattern of the sample. That is, graphite has a stacked structure of layers having a planar network structure of so-called benzene ring, as measured by powder X-ray diffraction, diffraction peak based on C ₀₀₂ is sharply interlayer distance d _{002 =} 0.335 nm It is observed as a sharp peak (2θ is about 25 °). Further, the half width (β) is measured from the diffraction line pattern, and the size of the crystallite is obtained by the following formula (2).
Lc ₀₀₂ = 91 / β (2)
When the raw coal of the present invention is heat-treated at 2800 ° C., the X-ray diffraction pattern is compared, which is very close to the structure of graphite.
In the present invention, the raw material oil and the production method thereof are not particularly limited as long as the raw coal satisfying the above conditions is obtained. However, the raw material oil is preferably hydrodesulfurized oil, fluid catalytic cracking obtained in the petroleum refining process. A raw material oil composition obtained by blending at least two raw material oils selected from residual oil and vacuum distillation residue oil is preferred.
As the raw material oil composition in the present invention, in particular, a heavy oil having specific properties (hereinafter referred to as a first heavy oil) obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more. What consists of a mixture of the heavy oil (henceforth a 2nd heavy oil) which has the specific property obtained by the fluid catalytic cracking of hydrocarbon oil is preferable.
The first heavy oil according to the present invention is obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more so that the hydrocracking rate is 30% or less under the condition of a total pressure of 16 MPa or more. It is a heavy oil with an initial boiling point of 200 ° C. or higher.
As described above, the sulfur content of the heavy oil used as the raw material oil for the first heavy oil is 2% by mass or more, preferably 2.5% by mass or more, and more preferably 3% by mass or more. Although an upper limit is not specifically limited, 5 mass% or less is preferable, More preferably, it is 4 mass% or less.
The heavy oil used as the first heavy oil feedstock is not particularly limited as long as the sulfur content satisfies the above conditions. For example, crude oil, atmospheric distillation residue obtained by distillation of crude oil, or reduced pressure Examples include distillation residual oil, visbreaking oil, tar sand oil, shale oil, and mixed oils thereof. Among these, atmospheric distillation residue and vacuum distillation residue are preferably used.
The hydrodesulfurization for obtaining the first heavy oil is performed under conditions of a total pressure of 16 MPa or more, preferably 17 MPa or more, more preferably 18 MPa or more. When the total pressure is less than 16 MPa, the heavy oil is excessively decomposed by hydrodesulfurization, and a heavy oil suitable as a raw oil composition for obtaining the raw coal of the present invention cannot be obtained. Although an upper limit is not specifically limited, 25 Mpa or less is preferable, More preferably, it is 22 Mpa or less.
The conditions other than the total pressure in hydrodesulfurization are not particularly limited as long as the hydrocracking rate is 30% or less, but it is preferable to set various conditions as follows. That is, the hydrodesulfurization temperature is preferably 300 to 500 ° C., more preferably 350 to 450 ° C., and the hydrogen / oil ratio is preferably 400 to 3000 NL / L, more preferably 500 to 1800 NL / L. The hydrogen partial pressure is preferably 7 to 20 MPa, more preferably 8 to 17 MPa, and the liquid space velocity (LHSV) is preferably 0.1 to 3 h ⁻¹ , more preferably 0.15 to 1.0 h ^{−. 1} and more preferably 0.15 to 0.75 h- ¹ .
Moreover, as a catalyst (hydrodesulfurization catalyst) used for hydrodesulfurization, a Ni-Mo catalyst, a Co-Mo catalyst, the catalyst which combined both, etc. are mentioned, These may use a commercial item.
Of the hydrodesulfurized oil obtained by the above hydrodesulfurization, a heavy oil having an initial boiling point of 200 ° C. or higher, preferably 250 ° C. or higher is used as the first heavy oil. The upper limit of the initial boiling point is not particularly limited, but is preferably 450 ° C. or lower, more preferably 400 ° C. or lower.
Further, the sulfur content of the first heavy oil is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, further preferably 0.35% by mass or less, and particularly preferably 0.3% by mass. % By mass or less, most preferably 0.25% by mass or less. When the sulfur content of the first heavy oil exceeds 0.5% by mass, it tends to induce early coking, and as a result, the resulting raw coal has a structure with low crystallinity, and the raw coal is activated with alkali. The residual alkali metal in the activated carbon thus obtained is not preferable, and needle coke obtained by calcining the raw coal is not preferable because puffing tends to occur.
The asphaltene content of the first heavy oil is preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less. When the asphaltene content of the first heavy oil exceeds 5% by mass, early coking is promoted, and as a result, the resulting raw coal has a structure with low crystallinity, and the activated carbon obtained by alkali activation of the raw coal This is not preferable because the residual alkali metal increases, and the thermal expansion coefficient of needle coke obtained by calcination of the raw coal tends to increase, which is not preferable.
The saturated content of the first heavy oil is preferably 60% by mass or more, more preferably 65% by mass or more, and further preferably 70% by mass or more. On the other hand, the upper limit is preferably 85% by mass or less, and more preferably 80% by mass or less. When the saturated content of the first heavy oil is less than 60% by mass, the orientation of the mesophase is deteriorated, and the raw coal has a low crystallinity structure, which is not preferable.
The density of the first heavy oil at 15 ° C. is preferably 0.85 to 0.89 g / cm ³ .
The second heavy oil according to the present invention is a heavy oil having an initial boiling point of 150 ° C. or higher obtained by fluid catalytic cracking of hydrocarbon oil and a sulfur content of 0.5% by mass or less.
Here, “fluid catalytic cracking” means a process of cracking a high-boiling fraction using a solid acid catalyst or the like. The fluid catalytic cracking apparatus used for such treatment is also called an FCC (Fluidized Catalytic Cracking) apparatus.
The hydrocarbon oil that is the raw material oil of the second heavy oil is not particularly limited as long as it can obtain a heavy oil whose initial boiling point and sulfur content satisfy the above conditions by fluid catalytic cracking, A hydrocarbon oil having a density at 15 ° C. of 0.8 g / cm ³ or more is preferred.
Such hydrocarbon oils include straight-run gas oil, vacuum gas oil, desulfurized gas oil, desulfurized vacuum gas oil, atmospheric distillation residual oil, vacuum distillation residual oil, shale oil, tar sand bitumen, orinocotal, coal liquefied oil, Examples include hydrorefined products and mixtures thereof. In the present invention, vacuum gas oil and desulfurized vacuum gas oil are particularly preferably used.
The conditions for fluid catalytic cracking are not particularly limited as long as it is possible to obtain a heavy oil whose initial boiling point and sulfur content satisfy the above conditions. For example, the reaction temperature is 480 to 550 ° C., the total pressure is 1 to 3 kg. / Cm ² G (98 to 294 kPa gauge pressure), catalyst / oil ratio of 1 to 20 wt / wt, and contact time of 1 to 10 seconds are preferable.
Examples of the catalyst used for fluid catalytic cracking include a silica / alumina catalyst, a zeolite catalyst, or a catalyst in which a metal such as platinum is supported on these catalysts. A commercial item may be used for these catalysts.
The initial boiling point of the second heavy oil thus obtained is required to be 150 ° C. or higher, preferably 200 ° C. or higher, more preferably 220 ° C. or higher. If the initial boiling point is lower than 150 ° C., the yield of raw coal is reduced, and the resulting raw coal has an amorphous structure, and the remaining alkali metal in the activated carbon obtained by alkali activation of the raw coal is obtained. This is not preferable because the amount increases, and the thermal expansion coefficient of needle coke obtained by calcining the raw coal is increased. The upper limit of the initial boiling point is preferably 350 ° C. or lower, more preferably 300 ° C. or lower.
Further, the sulfur content of the second heavy oil needs to be 0.5% by mass or less, preferably 0.4% by mass or less, more preferably 0.3% by mass or less. If the sulfur content exceeds 0.5 mass%, there is a tendency to induce early coking, and the resulting raw coal has a coke structure with poor crystallinity, and the remaining alkali metal in the activated carbon obtained by alkali activation of the raw coal This is not preferable because the amount increases, and puffing of needle coke obtained by calcining the raw coal cannot be sufficiently suppressed.
The nitrogen content of the second heavy oil is not particularly limited, but is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and further preferably 0.1% by mass or less. . When the nitrogen content is more than 0.2% by mass, the needle coke puffing cannot be sufficiently suppressed.
The raw material oil composition of the present invention is preferably obtained by mixing the first heavy oil and the second heavy oil described above. Moreover, the raw material oil composition of the present invention may further contain a vacuum distillation residue oil in addition to the first heavy oil and the second heavy oil.
As the above-mentioned vacuum distillation residue oil, an initial boiling point of 300 ° C. or more obtained as a residue oil when petroleum is distilled under reduced pressure, an asphaltene content of 12 mass% or less, a saturation content of 50 mass% or more, and a sulfur content of 0.3 mass%. The following heavy oils are preferred. Examples of the petroleums include crude oil, vacuum distillation residue obtained by distillation of crude oil, and mixed oils thereof. The treatment conditions when the above petroleums are distilled under reduced pressure are not particularly limited as long as the boiling point, asphaltene content, saturated content and sulfur content of the obtained vacuum distillation residue oil satisfy the above conditions, but the pressure is preferably 30 kPa or less, The temperature is preferably 400 ° C. or higher.
As a mixing ratio of the first heavy oil and the second heavy oil, when the activated carbon used for the electrode material for the electric double layer capacitor is manufactured, the content of the first heavy oil in the obtained raw material oil composition The ratio is preferably 5% by mass or more, more preferably 10% by mass, further preferably 15% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. It mix | blends so that it may become. Moreover, when producing raw material coal for needle coke, the mixing ratio of the first heavy oil and the second heavy oil is preferably 1 to 50% by mass of the first heavy oil. More preferably, it is 5-50 mass%, and it is still more preferable that it is 15-50 mass%.
In the case of a combination of the first heavy oil, the second heavy oil, and the vacuum distillation residue oil, the content of the vacuum distillation residue oil is preferably 10% by mass or more, more preferably 20% by mass or more. More preferably, it is 30% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and still more preferably 50% by mass or less. At this time, the 1st heavy oil and the 2nd heavy oil are blended so that it may become 10 mass% or more, respectively.
Next, the raw material oil composition of the present invention is subjected to coking (carbonization) treatment.
Examples of the method for coking the raw material oil composition include a delayed coking method, a visbreaking method, a flexi coking method, a yurika process, and H-Oil. Among these, the delayed coking method is particularly preferable.
In the delayed coking method, the raw material oil composition is placed in a delayed coker and heat treated under pressure. The pressure of the delayed coker is preferably 300 to 800 kPa. The temperature is preferably 400 to 600 ° C, more preferably 450 to 550 ° C, and the time is preferably 24 to 72 hours, more preferably 36 to 60 hours.
By the coking process, carbide (raw coke) that becomes raw coal is obtained.
When the raw coal of the present invention is graphitized at a temperature of 2800 ° C. in an inert gas atmosphere, the ratio of the crystallite size and the lattice constant of the graphitized material is 360 or less, more preferably 350 or less on the 002 plane. , 110 has a structure of 1500 or less, more preferably 1300 or less.
The sulfur content of the raw coal of the present invention is usually 0.3% by mass or less, and the bulk specific gravity is usually 0.55 or more.
The raw coal of the present invention preferably has a true specific gravity of not less than 2.23, more preferably not less than 2.24 when graphitized at 2800 ° C. in an inert gas atmosphere. . If the true specific gravity is less than 2.23, the crystallites are randomly arranged, and the edge surfaces are closed by the crystallite surfaces.
In the present invention, when the first heavy oil alone or the mixed oil of the first heavy oil and the second heavy oil is heat-treated at 500 ° C., it is 10 μm or less present in the raw coal. The proportion of the mosaic structure is as small as 2% or less, preferably 1% or less. Here, a small proportion of a mosaic structure of 10 μm or less in the raw coal means that the growth state of liquid crystal called mesophase is good. The mesophase is an intermediate product produced by thermal decomposition and polycondensation accompanying heat treatment of the feedstock oil, and a series of aromatic rings developed along the same plane.
The method for measuring the mosaic structure in the raw coal is as described in “Basics of Carbonization Engineering”, Yuzo Sanada and Sugirou Otani (Ohm), page 147.
Conventionally, when a raw material oil contains a large amount of a saturated component, particularly an aliphatic component, a crosslinking reaction occurs in addition to the polymerization and polycondensation of aromatic components during coking, so that a three-dimensional crystal grows and the mesophase is sufficient. It is considered that the structure does not grow and the crystallinity is inferior, and as a result, the coefficient of thermal expansion of needle coke is considered to increase, and the amount of residual alkali metal in the activated carbon is considered to increase. In view of this point, even if the saturated content of the first heavy oil is 50% by mass or more, a mosaic structure of 10 μm or less does not exist at all, or even if present, coking coal having 2% or less can be obtained. That is a surprising result.
The raw coal obtained by the coking process can be converted into activated carbon by an alkali activation treatment. Moreover, in carrying out the alkali activation treatment, it is also preferably employed that the raw coal is heat treated at 550 to 900 ° C., preferably 600 to 850 ° C. under an inert atmosphere and normal pressure, and then subjected to the alkali activation treatment.
In the present invention, the activated carbon thus obtained is used as an electrode material for an electric double layer capacitor.
As a method for activating the raw coal or the raw material for heat treatment of raw material carbon, an activation furnace is used to heat the raw material coal or the raw material for heat treatment of raw material coal at 500 to 1200 ° C. together with a metal hydroxide in an atmosphere of nitrogen gas or inert gas. A method can be mentioned. Specific examples of the metal hydroxide include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide, and alkaline earth metal hydroxides such as magnesium hydroxide and barium hydroxide. be able to. Moreover, not only 1 type but 2 or more types can also be used in combination. Of these, potassium hydroxide is particularly preferable because it can efficiently form micropores.
The amount of the raw coal or raw material heat treated carbon and metal hydroxide can be 1 / 0.5 to 1/10 in the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide, Preferably it is 1/1 to 1/5.
By setting the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide to 1 / 0.5 or less, it is possible to sufficiently form micropores in the activated carbon and obtain activated carbon having a sufficient surface area. it can. Moreover, by making the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide to 1/10 or more, the activation reaction can be efficiently performed without lowering the bulk density.
In addition, in the activation reaction, water or the like may coexist in addition to the raw coal or the raw material heat-treated with the raw coal and the metal hydroxide.
In the activation of the raw coal or the raw material for heat treatment of raw coal, the activation temperature may be, for example, in the range of 500 to 1200 ° C, preferably 600 to 1000 ° C, more preferably 600 to 800 ° C. Can do. When the activation temperature is in the above range, activated carbon having sufficient fine pores can be obtained efficiently. The activation treatment time can be appropriately selected in relation to conditions such as temperature, and can include 3 to 6 hours, for example.
Examples of the inert gas at the time of activation include inert gas and nitrogen gas. For example, it is preferable to supply such that the oxygen concentration in the activation atmosphere can be maintained at 100 ppm by volume or less.
The cleaning of the activated material is a cleaning in which the activated material is washed with a cleaning liquid to perform solid-liquid separation. The activated material is immersed in the cleaning liquid and mixed with the cleaning liquid by stirring and heating as necessary, and then the cleaning liquid is removed. The method of doing can be mentioned. As the cleaning liquid, water and an aqueous acid solution are preferably used. For example, cleaning with water, cleaning with an aqueous acid solution, and further cleaning with water can be used in appropriate combination. Preferred examples of the acid aqueous solution include hydrohalic acids such as hydrochloric acid, hydroiodic acid, and hydrobromic acid, and inorganic acids such as sulfuric acid and carbonic acid. Examples of the concentration of the acid aqueous solution include 0.01 to 3N. Cleaning with these cleaning liquids can be repeated a plurality of times as necessary.
After the final washing of the washing step using the washing liquid, solid-liquid separation is performed from the washing liquid, and heating, air drying, and the like are performed as appropriate to remove moisture and obtain dried activated carbon.
The activated carbon obtained by alkali activation of the raw coal or raw material heat treated carbon of the present invention has a feature that the residual alkali metal is reduced when washed by the same washing operation as compared with the conventional activated carbon. The reason why the residual alkali metal is reduced is that the raw coal and the raw material heat-treated with the coal according to the present invention have a crystal structure in which the metal hydroxide of the activator can easily enter and escape, and the obtained activated carbon This is considered to be due to the crystal structure that makes it easy for the cleaning liquid to enter and escape.
In addition to this, when the activated carbon according to the present invention is used for an electrode of an electric double layer capacitor, it is easy for electrolyte ions to enter and exit during charge and discharge, and the capacitance retention rate in the cycle characteristic test is improved. .
The electric double layer capacitor of the present invention uses activated carbon obtained from the raw coal of the present invention or a heat-treated product of raw coal as an electrode material.
The electrode of the electric double layer capacitor of the present invention is not particularly limited as long as it contains the above activated carbon, but may contain a binder, a conductive agent, etc., and is integrated with the current collector. It may be what you did.
As the binder, known ones can be used, and specifically, fluorinations such as polyolefins such as polyethylene and polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, and fluoroolefin / vinyl ether copolymer cross-linked polymers. Examples thereof include polymers, celluloses such as carboxymethyl cellulose, vinyl polymers such as polyvinyl pyrrolidone and polyvinyl alcohol, and polyacrylic acid. Specifically, the content of the binder in the electrode material may be 0.1 to 30% by mass.
Specific examples of the conductive agent include powders such as carbon black, acetylene black, and powdered graphite. As content in the electrode material of a electrically conductive agent, the range of 1-50 mass% is preferable, More preferably, it is 2-30 mass%.
In order to produce an electrode using these materials, for example, a method of adding the activated carbon, the binder, and a conductive agent to a solvent that dissolves the binder and applying the slurry as a slurry to a sheet-like current collector, Examples thereof include a method in which the activated carbon, the binder, and the conductive agent are kneaded without using a solvent and pressure-molded at room temperature or under heating.
As the current collector, known materials and shapes can be used, and specific examples include metals such as aluminum, titanium, tantalum, and nickel, and alloys such as stainless steel.
The electric double layer capacitor of the present invention can be produced as a unit cell in which a pair of electrodes are provided with a positive electrode and a negative electrode facing each other through a separator and immersed in an electrolyte solution. As the separator, unemployed cloth made of polypropylene fiber or glass fiber, cellulose paper, or the like can be used.
As the electrolytic solution, an aqueous electrolytic solution or a non-aqueous electrolytic solution can be used, but it is preferable to use a non-aqueous electrolytic solution. Examples of the non-aqueous electrolyte include those obtained by dissolving an electrolyte in an organic solvent. Specific examples of the solvent include propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, sulfolane, and 3-methylsulfolane. Such as sulfolane derivatives, 1,2-dimethoxyethane, etc., dimethoxyethane, acetonitrile, glutaronotolyl, valeronitrile, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, methyl formate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, etc. Can be used alone or in combination of two or more. Examples of the electrolyte of the electrolytic solution include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, cyclic quaternary ammonium salts, and quaternary phosphonium salts. _{C 2 H 5) 4 NBF 4} , (C 2 H 5) 3 (CH 3) NBF 4, (C 2 H 5) 4 PBF 4, (C 2 H 5) 3 (CH 4) PBF 4 and the like Can do. The electrolyte concentration in the electrolytic solution can be 0.1 to 5 mol / L, and preferably 0.5 to 5 mol / L.
As the shape of the electric double layer capacitor of the present invention, for example, a coin type and a pair of electrodes in which a pair of electrodes of a sheet shape or a disk shape having a thickness of 50 to 500 μm are housed in a metal case via a separator. Examples thereof include a wound type wound through a separator, and a laminated type in which a pair of electrodes provided via a separator are provided in multiple layers.
In the electric double layer capacitor of the present invention, since the activated carbon is used as an electrode material, cycle characteristics are improved, and excellent durability and excellent capacity retention are exhibited.
Moreover, the above-described raw coal of the present invention can be made into needle coke by further calcination in a rotary kiln, a shaft furnace or the like. The temperature during calcination is preferably 800 to 1600 ° C, more preferably 1000 to 1500 ° C. The calcination time is usually 1 to 10 hours, preferably 2 to 6 hours.
The needle coke of the present invention preferably has a sulfur content of 0.5% by mass or less, a nitrogen content of 0.1% by mass or less, and a bulk specific gravity of 0.82 or more.
The needle coke of the present invention has a coefficient of thermal expansion that is sufficiently small and puffing is sufficiently suppressed.
As a method for suppressing puffing, the use of an anti-puffing agent (puffing inhibitor) is conventionally known. In this method, the anti-puffing agent becomes an impurity and the quality of the electrode (especially thermal expansion coefficient, density, etc.) May be adversely affected. In contrast, the needle coke of the present invention is very useful in that puffing can be sufficiently suppressed without using an anti-puffing agent and the thermal expansion coefficient of the needle coke can be sufficiently reduced.
The needle coke of the present invention is suitably used as an aggregate of a graphite electrode for electric steelmaking. As a method for producing a graphite electrode product using the needle coke of the present invention, a raw material obtained by adding an appropriate amount of binder pitch to the needle coke of the present invention is heated and mixed, and then extruded to obtain a raw electrode. The method of processing after baking and graphitizing an electrode is mentioned.
In the present invention, “sulfur content” means a value measured in accordance with JIS K2541 in the case of oil, and a value measured in accordance with JIS M 8813 in the case of coke. The “nitrogen content” means a value measured according to JIS K 2609 in the case of oil, and a value measured according to JIS M 8813 in the case of coke. Further, “saturated content” and “asphaltene content” mean values measured using a thin layer chromatograph.

  The raw coal of the present invention is suitably used for producing activated carbon for electric double layer capacitor electrodes and also for producing needle coke.

＜実施例３＞
（１）原料油組成物の調製
先ず、硫黄分３．５質量％の常圧蒸留残油を、Ｎｉ−Ｍｏ触媒の存在下、水素化分解率が３０％以下となるように水素化脱硫し、脱硫重質油（以下、「水素化脱硫油Ｂ」という。）を得た。水素化脱硫条件は、全圧１８．５ＭＰａ、水素分圧１６．５ＭＰａ、温度３７０℃、水素／油比５９０ＮＬ／Ｌ、液空間速度（ＬＨＳＶ）０．１７ｈ^−１とした。得られた水素化脱硫油Ｂの初留点は２６０℃であり、硫黄分は０．３質量％、窒素分は０．１質量％、アスファルテン分は２質量％、飽和分は７０質量％であった。
この水素化脱硫油Ｂを試験管に入れ、常圧、５００℃で３時間熱処理を行いコークス化した。生成したコークスを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織は認められなかった。
また、脱硫減圧軽油（硫黄分５００質量ｐｐｍ、１５℃における密度０．８８ｇ／ｃｍ^３）を流動接触分解し、流動接触分解残油（以下、「流動接触分解残油Ｂ」という。）を得た。得られた流動接触分解残油Ｂの初留点は２１０℃であり、硫黄分は０．１質量％、窒素分は０．１質量％、アスファルテン分は０質量％、飽和分は３０質量％であった。
この流動接触分解残油Ｂを試験管に入れ、常圧、５００℃で３時間熱処理を行いコークス化した。生成したコークスを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織の存在は認められなかった。
（２）原料炭の調製
次に、水素化脱硫油Ｂと流動接触分解残油Ｂとを質量比２：８で混合し、原料油組成物Ｃを得た。この原料油組成物Ｃを、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化し、コークス（原料炭Ｃ）を得た。この原料炭Ｃを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織は認められなかった。
（３）原料炭の賦活
原料炭Ｃの１質量部と、水酸化カリウム（ＫＯＨ）２．５質量部とを混合し、ニッケル製反応容器に入れ、窒素下７５０℃で１時間加熱し、賦活処理を行った。
賦活処理後、反応容器内部の反応混合物を３００℃まで冷却し、窒素に替えて二酸化炭素を流し、金属カリウムを失活させた。この後、反応物２ｋｇに２０ｋｇの水を加え、室温で１時間攪拌の後、加圧ろ過した。この操作を２回行った。続いて、０．３Ｎ塩酸を２０ｋｇ加え、３時間攪拌し、加圧ろ過した。さらに２０ｋｇの水を加え、１時間攪拌の後、加圧ろ過した。この操作も２回行った。得られた固形物を１３０℃で乾燥して電気二重層キャパシタ用活性炭を得た。活性炭の比表面積および残存カリウム量を表３に示す。
（４）電気二重層キャパシタの作製
上記で得られた活性炭を用いた以外は実施例１と同様の操作で電気二重層キャパシタを作成した。このようにして作製した電気二重層キャパシタセルの静電容量、およびサイクル特性（１０００回充放電を繰り返した後の静電容量の保持率）を表３に示す。
＜実施例４＞
上記水素化脱硫油Ｂと流動接触分解残油Ｂとを質量比８：２で混合し、原料油組成物Ｄを得た。この原料油組成物Ｄを４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化し、コークス（原料炭Ｄ）を得た。原料炭Ｄの１質量部と、水酸化カリウム（ＫＯＨ）２．５質量部とを混合し、ニッケル製反応容器に入れ、窒素下７５０℃で１時間加熱し、賦活処理を行った以外は、実施例３と同様の操作を行い、電気二重層キャパシタ用活性炭を得た。活性炭の比表面積および残存カリウム量を表３に示す。また、上記活性炭を用いて、実施例１と同様の操作で電気二重層キャパシタを作製した。電気二重層キャパシタセルの静電容量およびサイクル特性（１０００回充放電を繰り返した後の静電容量の保持率）を表３に示す。
＜比較例３＞
実施例３で得られた流動接触分解残油Ｂのみを、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化し、しかる後、実施例３と同様の操作で、アルカリ賦活処理を行い、得られた活性炭を用いて電気二重層キャパシタを作製した。活性炭の比表面積および残存カリウム量、並びに、電気二重層キャパシタセルの静電容量およびサイクル特性（１０００回充放電を繰り返した後の静電容量の保持率）を表３に示す。
＜比較例４＞
常圧蒸留残油（密度０．９２ｇ／ｃｍ^３、硫黄分０．３５質量％）を、加熱炉出口温度３５０℃、圧力１．３ｋＰａの条件下で減圧蒸留し、初留点４１０℃、アスファルテン分９質量％、飽和分６１質量％、硫黄分０．１質量％の減圧蒸留残渣油（以下、「減圧蒸留残渣油Ｂ」という。）を得た。上記減圧蒸留残渣油Ｂを４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化し、しかる後、実施例３と同様の操作で、アルカリ賦活処理を行い、得られた活性炭を用いて電気二重層キャパシタを作製した。活性炭の比表面積および残存カリウム量、並びに、電気二重層キャパシタセルの静電容量およびサイクル特性（１０００回充放電を繰り返した後の静電容量の保持率）を表３に示す。
表３より明らかなように、水素化脱硫油と流動接触分解残油を混合して得られる本発明の原料油組成物を用いることにより、得られる活性炭中に残存するカリウム量を大幅に低減させることができ、その結果、それを用いた電気二重層キャパシタの静電容量保持率を向上させることができた。

＜実施例５＞
実施例３で用いた水素化脱硫油Ｂと流動接触分解残油Ｂとを質量比１：３で混合し、原料油組成物Ｅを得た。この原料油組成物Ｅを試験管に入れ、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化し、コークス（原料炭Ｅ）を得た。この原料炭Ｅを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織の存在は認められなかった。また、原料炭Ｅを窒素雰囲気下、２８００℃で熱処理して、黒鉛化物を得た。この黒鉛化物のＸ線回折測定結果（学振法１１７委員会）を表４に示す。
次に、原料炭Ｅを１０００℃で５時間焼成してか焼コークスを得た。得られたか焼コークスの硫黄分、窒素分及び嵩比重を表５に示す。
また、か焼コークスに石炭系のバインダーピッチを３０質量％加え、押し出し成形器で円柱状のピースを作製した。このピースをマッフル加熱炉を用いて１０００℃で１時間焼成し、焼成後の熱膨張係数を測定した。さらに、ピースを室温から２８００℃まで熱処理し、この過程での膨張の度合いをパッフィングとして測定した。得られた結果を表５に示す。
＜実施例６＞
水素化脱硫油Ｂと流動接触分解残油Ｂとを質量比１：５で混合し、原料油組成物Ｆを調製した。この原料油組成物Ｆを試験管に入れ、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化し、コークス（原料炭Ｆ）を得た。この原料炭Ｆを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織の存在は認められなかった。また、原料炭Ｅを窒素雰囲気下、２８００℃で熱処理して、黒鉛化物を得た。この黒鉛化物のＸ線回折測定結果（学振法１１７委員会）を表４に示す。
次に、原料炭Ｆを１０００℃で５時間焼成してか焼コークスを得た。得られたか焼コークスの硫黄分、窒素分及び嵩比重を表５に示す。
このか焼コークスを用いた以外は実施例５と同様の方法で、円柱状のピースを作製して熱膨張係数およびパッフィングを測定した。その結果を表５に示す。
＜比較例５＞
流動接触分解残油Ｂを試験管に入れ、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化した。また、このコークスを窒素雰囲気下、２８００℃で熱処理して、黒鉛化物を得た。この黒鉛化物のＸ線回折測定結果（学振法１１７委員会）を表４に示す。
次に、生成したコークスを１０００℃で５時間焼成してか焼コークスを得た。得られたか焼コークスの硫黄分、窒素分及び嵩比重を表５に示す。
このか焼コークスを用いた以外は実施例５と同様の方法で、円柱状のピースを作製して熱膨張係数およびパッフィングを測定した。その結果を表５に示す。
＜比較例６＞
硫黄分０．２質量％、窒素分０．３質量％、飽和分４０質量％の低硫黄原油を減圧蒸留し、減圧蒸留残渣油（以下、「減圧蒸留残渣油Ｃ」という。）を得た。この減圧蒸留残渣油Ｃを試験管に入れ、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化した。生成したコークスを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織は１８％であった。また、このコークスを窒素雰囲気下、２８００℃で熱処理して、黒鉛化物を得た。この黒鉛化物のＸ線回折測定結果（学振法１１７委員会）を表４に示す。
次に、生成したコークスを１０００℃で５時間焼成してか焼コークスを得た。得られたか焼コークスの硫黄分、窒素分及び嵩比重を表５に示す。
このか焼コークスを用いた以外は実施例５と同様の方法で、円柱状のピースを作製して熱膨張係数およびパッフィングを測定した。その結果を表５に示す。
＜比較例７＞
減圧蒸留残渣油Ｃと流動接触分解残油Ｂとを質量比１：１で混合し、原料油組成物を調製した。この原料油組成物を試験管に入れ、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化した。生成したコークスを市販の樹脂に埋め込み偏光顕微鏡で観察したところ、１０μｍ以下のモザイク組織は５％であった。また、このコークスを窒素雰囲気下、２８００℃で熱処理して、黒鉛化物を得た。この黒鉛化物のＸ線回折測定結果（学振法１１７委員会）を表４に示す。
次に、生成したコークスを１０００℃で５時間焼成してか焼コークスを得た。得られたか焼コークスの硫黄分、窒素分及び嵩比重を表５に示す。
このか焼コークスを用いた以外は実施例５と同様の方法で、円柱状のピースを作製して熱膨張係数およびパッフィングを測定した。その結果を表５に示す。
＜比較例８＞
減圧蒸留残渣油Ｃと流動接触分解残油Ｂとを質量比１：５で混合し、原料油組成物を調製した。この原料油組成物を試験管に入れ、４００ｋＰａ下、５００℃で４０時間熱処理を行いコークス化した。このコークスを窒素雰囲気下、２８００℃で熱処理して、黒鉛化物を得た。この黒鉛化物のＸ線回折測定結果（学振法１１７委員会）を表４に示す。
次に、生成したコークスを１０００℃で５時間焼成してか焼コークスを得た。得られたか焼コークスの硫黄分、窒素分及び嵩比重を表５に示す。
このか焼コークスを用いた以外は実施例５と同様の方法で、円柱状のピースを作製して熱膨張係数およびパッフィングを測定した。その結果を表５に示す。

EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example and a comparative example, this invention is not limited to a following example.
<Example 1>
(1) Preparation of raw material oil composition Hydrodesulfurization of middle-eastern atmospheric distillation residue having a sulfur content of 2.5% by mass in the presence of a Ni-Mo catalyst so that the hydrocracking rate is 25% or less. Thus, desulfurized heavy oil (hereinafter referred to as “hydrodesulfurized oil A”) was obtained. The hydrodesulfurization conditions were a total pressure of 22 MPa, a hydrogen partial pressure of 20 MPa, a temperature of 380 ° C., a hydrogen / oil ratio of 590 NL / L, and a liquid space velocity (LHSV) of 0.17 h ⁻¹ .
Also, using a vacuum distillation residual oil and desulfurized vacuum gas oil as raw material, a catalyst in which platinum (Pt) is supported on silica / alumina, a reaction temperature of 520 ° C., a total pressure of 0.2 MPa, a catalyst / oil ratio of 7, contact A fluid catalytic cracking residual oil (hereinafter referred to as “fluid catalytic cracking residual oil A”) was obtained at a time of 3 seconds.
Subsequently, the hydrodesulfurized oil A and the fluid catalytic cracking residual oil A were mixed at a mass ratio of 5: 5 to obtain a raw material oil composition A.
(2) Preparation of raw coal Next, the raw oil composition A was subjected to coking treatment at 500 ° C. under nitrogen and 400 kPa for 40 hours to obtain coke (raw coal A). This raw coal A was heat-treated at 2800 ° C. under nitrogen to obtain a graphitized product. Table 1 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
(3) Activation of raw coal Coal 1 part by mass of raw coal A and 2.5 parts by weight of potassium hydroxide (KOH) are mixed, put into a nickel reaction vessel, heated at 700 ° C. for 1 hour under nitrogen, and activated. Went.
After the activation treatment, the reaction mixture inside the reaction vessel was cooled to 250 ° C., and carbon dioxide was flowed in place of nitrogen to deactivate the metal potassium. Thereafter, 20 kg of water was added to 2 kg of the reaction product, stirred at room temperature for 1 hour, and filtered under pressure. This operation was performed twice. Subsequently, 20 kg of 0.3N hydrochloric acid solution was added, stirred for 3 hours, and filtered under pressure. An additional 20 kg of water was added, and the mixture was stirred for 1 hour and filtered under pressure. This operation was also performed twice. The obtained solid was dried at 130 ° C. to obtain activated carbon for an electric double layer capacitor electrode. Table 2 shows the specific surface area, residual potassium amount and true specific gravity of the activated carbon.
(4) Production of electric double layer capacitor Activated carbon (0.8 g), Ketjen black (0.1 g) and polytetrafluoroethylene (0.1 g) obtained above were mixed in a mortar. This mixture was sandwiched between two 0.1 mm thick triacetate films and rolled by passing 20 times between nip rolls having a width of 160 mm, an upper and lower roll interval of 0.7 mm, and a pressure of 23.0 MPa. Two circles having a diameter of 16 mm were punched out from the rolled sheet to obtain carbon electrodes. The carbon electrode was dried in a vacuum dryer for 2 hours.
A cellulose separator having a thickness of 50 μm is sandwiched between two electrodes impregnated with an electrolyte (1 mol of (C ₂ H ₅ ) ₃ (CH ₃ ) NBF ₄ dissolved in 1 liter of propylene carbonate) It enclosed in the coin cell made from SUS316 of diameter 20mm. In this case, a current collector carbon coating applied to the surface of a 20 μm thick aluminum foil was used as a current collector, and the paint side was sandwiched between the carbon electrode and the cell so as to face the carbon electrode.
Table 2 shows the capacitance and cycle characteristics (capacitance retention rate after 1000 charge / discharge cycles) of the electric double layer capacitor cell thus fabricated.
<Example 2>
An atmospheric distillation residue having a sulfur content of 3.0% by mass was distilled under reduced pressure at a heating furnace outlet temperature of 360 ° C. and a pressure of 1.3 kPa, an initial boiling point of 410 ° C., an asphaltene content of 8% by mass, and a saturation content of 50%. % Distillation residue oil A having a sulfur content of 0.1% by mass and a nitrogen content of 0.3% by mass was obtained.
Subsequently, the composition of the hydrodesulfurized oil A and the fluid catalytic cracking residual oil A of Example 1 was mixed so that the above-mentioned reduced-pressure distillation residue oil A was 30% by mass to obtain a raw material oil composition B.
Next, the raw material oil composition B was subjected to coking treatment at 500 ° C. for 40 hours under nitrogen and 400 kPa to obtain coke (raw coal B). This raw coal B was heat-treated at 2800 ° C. under nitrogen to obtain a graphitized product. Table 1 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
An activation reaction and a capacitor were produced in the same manner as in Example 1 except that the raw coal B was used instead of the raw coal A. Table 2 shows the specific surface area of the activated carbon, the amount of residual potassium and the true specific gravity, and the capacitance and cycle characteristics of the capacitor cell (capacitance retention rate after 1000 charge / discharge cycles).
<Comparative Example 1>
The fluid catalytic cracking residual oil A used in Example 1 was subjected to coking treatment under nitrogen and 400 kPa at 500 ° C. for 40 hours to obtain coke. The coke was then heat treated at 2800 ° C. under nitrogen. Table 1 shows the X-ray diffraction measurement results (Gakushin 117 committee) of this heat-treated product. Further, the specific surface area, the residual potassium amount and the true specific gravity of the activated carbon obtained by alkali activation of the coke under the conditions of Example 1, and the capacitance and cycle characteristics of the capacitor cell (static capacity after 1000 charge / discharge cycles) Table 2 shows the retention rate of electric capacity.
<Comparative example 2>
The vacuum distillation residue oil A used in Example 2 was subjected to coking treatment under nitrogen, 400 kPa, and 500 ° C. for 40 hours to obtain coke. The coke was then heat treated at 2800 ° C. under nitrogen. Table 1 shows the X-ray diffraction measurement results (Gakushin 117 committee) of this heat-treated product. Further, the specific surface area, the residual potassium amount and the true specific gravity of the activated carbon obtained by alkali activation of the coke under the conditions of Example 1, and the capacitance and cycle characteristics of the capacitor cell (static capacity after 1000 charge / discharge cycles) Table 2 shows the retention rate of electric capacity.
From Table 1 and Table 2, when the ratio of the crystallite size and the lattice constant on the 002 and 110 planes of the 2800 ° C. heat-treated product is 360 or less on the 002 plane and 1500 or less on the 110 plane, it is obtained by activation with KOH. The amount of potassium remaining in the obtained activated carbon is small, and the cycle characteristics of the electric double layer capacitor obtained by using such activated carbon, that is, the retention rate of the capacitance after repeating 1000 times of charge and discharge It is clear that the capacitor characteristics are excellent.

<Example 3>
(1) Preparation of raw material oil composition First, hydrodesulfurization of atmospheric distillation residue having a sulfur content of 3.5% by mass in the presence of a Ni-Mo catalyst so that the hydrocracking rate is 30% or less. A desulfurized heavy oil (hereinafter referred to as “hydrodesulfurized oil B”) was obtained. The hydrodesulfurization conditions were a total pressure of 18.5 MPa, a hydrogen partial pressure of 16.5 MPa, a temperature of 370 ° C., a hydrogen / oil ratio of 590 NL / L, and a liquid space velocity (LHSV) of 0.17 h ⁻¹ . The obtained hydrodesulfurized oil B has an initial boiling point of 260 ° C., a sulfur content of 0.3% by mass, a nitrogen content of 0.1% by mass, an asphaltene content of 2% by mass, and a saturated content of 70% by mass. there were.
This hydrodesulfurized oil B was put in a test tube and heat-treated at normal pressure and 500 ° C. for 3 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, a mosaic structure of 10 μm or less was not observed.
Further, desulfurized vacuum gas oil (sulfur content: 500 mass ppm, density: 0.88 g / cm ^{3 at} 15 ° C.) is subjected to fluid catalytic cracking to obtain fluid catalytic cracking residual oil (hereinafter referred to as “fluid catalytic cracking residual oil B”). It was. The initial boiling point of the obtained fluid catalytic cracking residual oil B is 210 ° C., the sulfur content is 0.1% by mass, the nitrogen content is 0.1% by mass, the asphaltene content is 0% by mass, and the saturation content is 30% by mass. Met.
This fluid catalytic cracking residual oil B was put in a test tube and heat-treated at normal pressure and 500 ° C. for 3 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized.
(2) Preparation of raw coal Next, hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 2: 8 to obtain raw oil composition C. This raw material oil composition C was subjected to heat treatment at 400 ° C. for 40 hours at 400 ° C. to be coke to obtain coke (raw coal C). When this raw carbon C was embedded in a commercially available resin and observed with a polarizing microscope, a mosaic structure of 10 μm or less was not recognized.
(3) Activation of raw coal Coal 1 part by mass of raw coal C and 2.5 parts by mass of potassium hydroxide (KOH) are mixed, put into a nickel reaction vessel, heated at 750 ° C. for 1 hour under nitrogen, and activated. Processed.
After the activation treatment, the reaction mixture inside the reaction vessel was cooled to 300 ° C., and carbon dioxide was passed instead of nitrogen to deactivate the metal potassium. Thereafter, 20 kg of water was added to 2 kg of the reaction product, stirred at room temperature for 1 hour, and filtered under pressure. This operation was performed twice. Subsequently, 20 kg of 0.3N hydrochloric acid was added, stirred for 3 hours, and filtered under pressure. An additional 20 kg of water was added, and the mixture was stirred for 1 hour and filtered under pressure. This operation was also performed twice. The obtained solid was dried at 130 ° C. to obtain activated carbon for an electric double layer capacitor. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon.
(4) Production of electric double layer capacitor An electric double layer capacitor was produced in the same manner as in Example 1 except that the activated carbon obtained above was used. Table 3 shows the capacitance and cycle characteristics (capacitance retention rate after 1000 charge / discharge cycles) of the electric double layer capacitor cell thus fabricated.
<Example 4>
The hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 8: 2 to obtain a raw material oil composition D. This raw material oil composition D was subjected to heat treatment at 400 ° C. for 40 hours at 500 ° C. to be coke to obtain coke (raw coal D). Except that 1 part by mass of raw coal D and 2.5 parts by mass of potassium hydroxide (KOH) were mixed, put in a nickel reaction vessel, heated at 750 ° C. for 1 hour under nitrogen, and subjected to activation treatment, The same operation as in Example 3 was performed to obtain activated carbon for an electric double layer capacitor. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon. Moreover, the electric double layer capacitor was produced by the same operation as Example 1 using the said activated carbon. Table 3 shows the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of capacitance after repeating charge and discharge 1000 times).
<Comparative Example 3>
Only the fluid catalytic cracking residual oil B obtained in Example 3 was heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke, and then subjected to alkali activation treatment in the same manner as in Example 3 to obtain An electric double layer capacitor was fabricated using activated carbon. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon, and the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of the capacitance after repeating charge and discharge 1000 times).
<Comparative example 4>
An atmospheric distillation residue (density 0.92 g / cm ³ , sulfur content 0.35 mass%) was distilled under reduced pressure under conditions of a heating furnace outlet temperature of 350 ° C. and a pressure of 1.3 kPa to obtain an initial boiling point of 410 ° C. and asphaltene. A vacuum distillation residue oil (hereinafter referred to as “vacuum distillation residue oil B”) having a content of 9% by mass, a saturation content of 61% by mass and a sulfur content of 0.1% by mass was obtained. The reduced-pressure distillation residue oil B is heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke, and then subjected to an alkali activation treatment in the same manner as in Example 3, and the obtained activated carbon is used for an electric double layer capacitor. Was made. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon, and the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of the capacitance after repeating charge and discharge 1000 times).
As is apparent from Table 3, the amount of potassium remaining in the obtained activated carbon is greatly reduced by using the raw material oil composition of the present invention obtained by mixing hydrodesulfurized oil and fluid catalytic cracking residual oil. As a result, the electrostatic capacity retention rate of the electric double layer capacitor using the same can be improved.

<Example 5>
The hydrodesulfurized oil B and fluid catalytic cracking residual oil B used in Example 3 were mixed at a mass ratio of 1: 3 to obtain a raw material oil composition E. This raw material oil composition E was put into a test tube and heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke to obtain coke (raw coal E). When this raw coal E was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized. Further, the raw coal E was heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain a graphitized product. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the raw coal E was calcined at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
Further, 30% by mass of a coal-based binder pitch was added to calcined coke, and a cylindrical piece was produced with an extruder. This piece was fired at 1000 ° C. for 1 hour using a muffle heating furnace, and the thermal expansion coefficient after firing was measured. Furthermore, the piece was heat-treated from room temperature to 2800 ° C., and the degree of expansion in this process was measured as puffing. The results obtained are shown in Table 5.
<Example 6>
Hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 1: 5 to prepare a feed oil composition F. This raw material oil composition F was put in a test tube and heat-treated at 400 ° C. and 500 ° C. for 40 hours to be coke to obtain coke (raw coal F). When this raw carbon F was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized. Further, the raw coal E was heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain a graphitized product. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the raw coal F was calcined at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.
<Comparative Example 5>
The fluid catalytic cracking residual oil B was put into a test tube and heat treated at 500 ° C. under 400 kPa for 40 hours to be coke. Moreover, this coke was heat-processed at 2800 degreeC by nitrogen atmosphere, and the graphitized material was obtained. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.
<Comparative Example 6>
A low-sulfur crude oil having a sulfur content of 0.2% by mass, a nitrogen content of 0.3% by mass and a saturation content of 40% by mass was distilled under reduced pressure to obtain a vacuum distillation residue oil (hereinafter referred to as “vacuum distillation residue oil C”). . This vacuum distillation residue oil C was put into a test tube and heat-treated at 400 ° C. and 500 ° C. for 40 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the mosaic structure of 10 μm or less was 18%. Moreover, this coke was heat-processed at 2800 degreeC by nitrogen atmosphere, and the graphitized material was obtained. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.
<Comparative Example 7>
The vacuum distillation residual oil C and fluid catalytic cracking residual oil B were mixed at a mass ratio of 1: 1 to prepare a raw material oil composition. This raw material oil composition was put into a test tube and heat-treated at 500 ° C. under 400 kPa for 40 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the mosaic structure of 10 μm or less was 5%. Moreover, this coke was heat-processed at 2800 degreeC by nitrogen atmosphere, and the graphitized material was obtained. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.
<Comparative Example 8>
The vacuum distillation residue oil C and fluid catalytic cracking residue oil B were mixed at a mass ratio of 1: 5 to prepare a raw material oil composition. This raw material oil composition was put into a test tube and heat-treated at 500 ° C. under 400 kPa for 40 hours to be coke. The coke was heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain a graphitized product. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.

  The present invention relates to a raw material carbon for power storage carbon material and needle coke. In particular, the present invention relates to a raw material coal that provides activated carbon from which residual alkali metals can be easily removed as activated carbon for an electric double layer capacitor electrode. The present invention also relates to raw coal suitable for needle coke.

In recent years, carbon materials have been widely used in the field of electric power. As such a carbon material for power storage, for example, activated carbon having a relatively large surface area is used for an electrode of an electric double layer capacitor, and coke having a relatively small surface area is used as a negative electrode of a lithium ion secondary battery. Yes. In particular, electric double layer capacitors are attracting attention as backup power supplies, auxiliary power supplies, etc., and development focusing on the performance of activated carbon as an electrode for electric double layer capacitors has been widely made. Electric double layer capacitors using activated carbon as a polarizable electrode are excellent in electrostatic capacity, so that demand for electric device electrode applications and the like is growing rapidly with the development of the electronics field. Recently, in addition to the miniaturization of conventional memory backup power supplies, development of large-capacity products that can be used for auxiliary power supplies such as motors has been carried out.
As a method for producing these activated carbons, the carbonaceous material is subjected to a gas activation treatment or a chemical activation treatment, for example, an alkali activation treatment using an alkali metal hydroxide as an activation aid, and then an alkali metal or heavy metal from the activation treatment product. In order to remove water, neutralization washing with a strong acid such as hydrochloric acid, nitric acid or sulfuric acid is generally performed.

  With the demand for higher performance of electric double layer capacitors, there is a need to further reduce the residual alkali metal in activated carbon for electric double layer capacitor electrodes. However, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-123462), even if the alkali metal can be removed up to a certain level by repeated washing with water and pickling, it is difficult to remove it further. . For this reason, an electric double layer capacitor using a carbon material after alkali activation has an initial capacitor capacity, but has a problem of deterioration over time such that the capacitor capacity greatly decreases when used for a long time.

On the other hand, from the viewpoint of the cleaning operation, the cleaning operation is as simple as possible, that is, it is desirable that the number of times of cleaning is as small as possible in terms of cost. In Patent Document 2 (International Publication No. 2004-011371 pamphlet), an easily activated graphitized carbonaceous material is subjected to an alkali activation treatment, and the obtained activation treatment product is used as hot water, carbonated water, hot hydrochloric acid, aqueous ammonia, hot hydrochloric acid. In addition, although it is described that activated carbon is obtained by washing in order of hot water, since the washing operation is complicated, development of activated carbon having a structure in which residual alkali metal is easily removed has been strongly desired.
On the other hand, needle coke used for the aggregate of graphite electrodes for electric steelmaking is generally manufactured using petroleum heavy oil or coal tar as a raw material. In the process of producing a graphite electrode, first, coke grains and a binder pitch are blended at a predetermined ratio, heat-combined, and then extruded to produce a raw electrode. The raw electrode is fired, graphitized, and then processed to obtain a graphite electrode product.

Since the graphite electrode is used under severe conditions such as a high temperature atmosphere, it is desired that the coefficient of thermal expansion (CTE) is low. That is, the smaller the coefficient of thermal expansion, the smaller the electrode consumption during electric steelmaking, and the cost of electric steelmaking can be reduced.
In addition, the graphitization is a process of heat treatment at about 3000 ° C., and a method using a direct current type furnace (LWG furnace) is common, but when graphitization is performed using an LWG furnace, the rate of temperature rise Therefore, the gas generation speed increases, and an abnormal expansion phenomenon called puffing is likely to occur. When puffing occurs, the electrode is reduced in density, and in some cases, the electrode is damaged.

Therefore, methods for controlling the coefficient of thermal expansion and the quality of puffing during the manufacture of needle coke have been studied, and various methods have been proposed. For example, in Patent Document 3 (Japanese Patent Laid-Open No. 5-105881), an oligomer whose polymerization degree is adjusted is added to a de-QI pitch from which a quinoline insoluble matter is substantially removed from a coal tar-based raw material, and a delayed coking method is used as it is. A method of coking is disclosed. Patent Document 4 (JP-A-5-163491) describes a range in which coal tar heavy oil and petroleum heavy oil have a nitrogen content of 1.0 wt% or less and a sulfur content of 1.4 wt% or less. The raw oil is prepared by mixing the raw oil into a delayed coker, and the raw coke is calcined in the temperature range of 700 to 900 ° C. and cooled once. After that, the method of calcination again in the temperature range of 1200 to 1600 ° C. is disclosed. In Patent Document 5 (Japanese Patent Laid-Open No. 5-202362), when producing coal tar by rapid pyrolysis of coal, the pyrolysis temperature in the reactor is kept at 750 ° C. or higher, and A method is disclosed in which a liquid product is obtained by setting the residence time in the reactor to 5 seconds or less, and the liquid product or pitch contained therein is carbonized. Patent Document 6 (Japanese Patent Application Laid-Open No. 7-3267) discloses a raw material oil obtained by mixing a petroleum heavy oil alone or a mixture of a coal tar heavy oil from which the quinoline insoluble component has been previously removed with the petroleum heavy oil. As a petroleum-based heavy oil, a method using a pre-adjusted so that the content of particles such as ash is in the range of 0.05 wt% to 1 wt% is disclosed. ing.
However, even with the methods described in Patent Documents 3 to 6, the effect of reducing the thermal expansion coefficient or suppressing puffing is not necessarily sufficient, and the quality of the obtained coke is as an aggregate of graphite electrodes for electric steelmaking. The actual situation is that the required level has not yet been reached.
JP 2005-123462 A International Publication No. 2004-011371 Pamphlet JP-A-5-105881 JP-A-5-163491 JP-A-5-202362 Japanese Patent Laid-Open No. 7-3267

The inventors of the present invention have activated carbon obtained by alkali activation of raw coal having a specific structure, which makes it easy for the cleaning liquid to enter and exit during cleaning, and as a result, can reduce the residual alkali content in the activated carbon, It was found that the washing operation can be simplified.
Furthermore, the present inventors have found that needle coke obtained by further calcining such raw coal has a sufficiently small thermal expansion coefficient and puffing is sufficiently suppressed.
In the present invention, “coking coal” refers to a carbide used as a raw material for activated carbon or needle coke, obtained by coking a raw oil such as heavy oil or residual oil.

That is, the present invention has a structure in which the ratio of the crystallite size and the lattice constant of graphitized material when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. It is related with the raw material carbon for activated carbon for electric double layer capacitors or needle coke characterized by having.

  In addition, the present invention provides an initial boiling point of 200 ° C. or higher obtained by hydrodesulfurization of a heavy oil having a sulfur content of 2% by mass or more under a condition of a total pressure of 16 MPa or more so that the hydrocracking rate is 30% or less. And a second heavy oil having an initial boiling point of 150 ° C. or higher and a sulfur content of 0.5% by mass or less obtained by fluid catalytic cracking of hydrocarbon oil. The present invention relates to a raw material oil composition for producing the raw coal.

  Moreover, this invention relates to the manufacturing method of the said raw coal characterized by coking the said raw material oil composition at 300-800 kPa and 400-600 degreeC.

  The present invention also relates to activated carbon obtained by activating the raw coal or the raw coal heat-treated product obtained by heat-treating the raw coal at 550 to 900 ° C. under normal pressure with an alkali metal hydroxide.

  The present invention also relates to an electric double layer capacitor using the activated carbon as an electrode material.

  Furthermore, this invention relates to the needle coke obtained by calcining the said raw coal at 800-1600 degreeC.

  The activated carbon obtained by alkali activation of the raw coal of the present invention is easy for the cleaning solution to enter and exit, and as a result, the amount of remaining alkali metal is reduced even in the same cleaning operation, so the cycle of the electric double layer capacitor using it as an electrode material Improved characteristics. Moreover, since the washing operation is simplified, the activated carbon can be manufactured at a lower cost, and its industrial value is extremely large. Further, the needle coke obtained by further calcining the raw coal of the present invention has a sufficiently small coefficient of thermal expansion, and puffing is sufficiently suppressed.

Hereinafter, the present invention will be described in detail.
In the raw coal of the present invention, the ratio of the crystallite size and the lattice constant of the graphitized product when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. Gives structure. When the ratio of the crystallite size to the lattice constant on the 002 plane exceeds 360, or the ratio of the crystallite size to the lattice constant on the 110 plane exceeds 1500, the ratio of the edge plane to the crystallite of the raw coal is For this reason, it is considered that the amount of potassium remaining in the activated carbon increases because the cleaning solution cannot enter the crystallites through the edge surface and the cleaning effect is reduced.
Here, the interlayer distance d ₀₀₂ (lattice constant) of the microcrystalline carbon and the crystallite size Lc ₀₀₂ of the microcrystalline carbon were determined by the Japan Society for the Promotion of Science 117th Committee, “Lattice constant and crystallite of artificial graphite” In accordance with the “size measurement method”, the X-ray diffraction method is used as follows.

That is, sample powder (one obtained by graphitizing raw coal at 2800 ° C.) is filled in a sample holder, and an X-ray diffraction pattern is obtained using CuKα rays monochromatized by a graphite monochromator as a radiation source. The peak position of the diffraction pattern is obtained by the centroid method (a method of obtaining the centroid position of the diffraction line and obtaining the peak position using the corresponding 2θ value), and the diffraction peak of the (111) plane of the high-purity silicon powder for standard materials. Use to correct. Then, the wavelength of the CuKα ray is set to 0.15418 nm, and the interlayer distance d ₀₀₂ of microcrystalline carbon is calculated by the Bragg formula expressed by the following formula (1).
d ₀₀₂ = λ / (2 sin θ) (1)

The presence or absence of formation of the graphite structure in the sample can be confirmed, for example, by having a clear peak at 2θ of about 25 ° in the powder X-ray diffraction pattern of the sample. That is, graphite has a stacked structure of layers having a planar network structure of so-called benzene ring, as measured by powder X-ray diffraction, diffraction peak based on C ₀₀₂ is sharply interlayer distance d _{002 =} 0.335 nm It is observed as a sharp peak (2θ is about 25 °). Further, the half width (β) is measured from the diffraction line pattern, and the size of the crystallite is obtained by the following formula (2).
Lc ₀₀₂ = 91 / β (2)

When the raw coal of the present invention is heat-treated at 2800 ° C., the X-ray diffraction pattern is compared, which is very close to the structure of graphite.
In the present invention, the raw material oil and the production method thereof are not particularly limited as long as the raw coal satisfying the above conditions is obtained. However, the raw material oil is preferably hydrodesulfurized oil, fluid catalytic cracking obtained in the petroleum refining process. A raw material oil composition obtained by blending at least two raw material oils selected from residual oil and vacuum distillation residue oil is preferred.

  As the raw material oil composition in the present invention, in particular, a heavy oil having specific properties (hereinafter referred to as a first heavy oil) obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more. What consists of a mixture of the heavy oil (henceforth a 2nd heavy oil) which has the specific property obtained by the fluid catalytic cracking of hydrocarbon oil is preferable.

The first heavy oil according to the present invention is obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more so that the hydrocracking rate is 30% or less under the condition of a total pressure of 16 MPa or more. It is a heavy oil with an initial boiling point of 200 ° C. or higher.
As described above, the sulfur content of the heavy oil used as the raw material oil for the first heavy oil is 2% by mass or more, preferably 2.5% by mass or more, and more preferably 3% by mass or more. Although an upper limit is not specifically limited, 5 mass% or less is preferable, More preferably, it is 4 mass% or less.
The heavy oil used as the first heavy oil feedstock is not particularly limited as long as the sulfur content satisfies the above conditions. For example, crude oil, atmospheric distillation residue obtained by distillation of crude oil, or reduced pressure Examples include distillation residual oil, visbreaking oil, tar sand oil, shale oil, and mixed oils thereof. Among these, atmospheric distillation residue and vacuum distillation residue are preferably used.

The hydrodesulfurization for obtaining the first heavy oil is performed under conditions of a total pressure of 16 MPa or more, preferably 17 MPa or more, more preferably 18 MPa or more. When the total pressure is less than 16 MPa, the heavy oil is excessively decomposed by hydrodesulfurization, and a heavy oil suitable as a raw oil composition for obtaining the raw coal of the present invention cannot be obtained. Although an upper limit is not specifically limited, 25 Mpa or less is preferable, More preferably, it is 22 Mpa or less.
The conditions other than the total pressure in hydrodesulfurization are not particularly limited as long as the hydrocracking rate is 30% or less, but it is preferable to set various conditions as follows. That is, the hydrodesulfurization temperature is preferably 300 to 500 ° C., more preferably 350 to 450 ° C., and the hydrogen / oil ratio is preferably 400 to 3000 NL / L, more preferably 500 to 1800 NL / L. The hydrogen partial pressure is preferably 7 to 20 MPa, more preferably 8 to 17 MPa, and the liquid space velocity (LHSV) is preferably 0.1 to 3 h ⁻¹ , more preferably 0.15 to 1.0 h ^{−. 1} and more preferably 0.15 to 0.75 h- ¹ .
Moreover, as a catalyst (hydrodesulfurization catalyst) used for hydrodesulfurization, a Ni-Mo catalyst, a Co-Mo catalyst, the catalyst which combined both, etc. are mentioned, These may use a commercial item.

Of the hydrodesulfurized oil obtained by the above hydrodesulfurization, a heavy oil having an initial boiling point of 200 ° C. or higher, preferably 250 ° C. or higher is used as the first heavy oil. The upper limit of the initial boiling point is not particularly limited, but is preferably 450 ° C. or lower, more preferably 400 ° C. or lower.
Further, the sulfur content of the first heavy oil is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, further preferably 0.35% by mass or less, and particularly preferably 0.3% by mass. % By mass or less, most preferably 0.25% by mass or less. When the sulfur content of the first heavy oil exceeds 0.5% by mass, it tends to induce early coking, and as a result, the resulting raw coal has a structure with low crystallinity, and the raw coal is activated with alkali. The residual alkali metal in the activated carbon thus obtained is not preferable, and needle coke obtained by calcining the raw coal is not preferable because puffing tends to occur.

The asphaltene content of the first heavy oil is preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less. When the asphaltene content of the first heavy oil exceeds 5% by mass, early coking is promoted, and as a result, the resulting raw coal has a structure with low crystallinity, and the activated carbon obtained by alkali activation of the raw coal This is not preferable because the residual alkali metal increases, and the thermal expansion coefficient of needle coke obtained by calcination of the raw coal tends to increase, which is not preferable.
The saturated content of the first heavy oil is preferably 60% by mass or more, more preferably 65% by mass or more, and further preferably 70% by mass or more. On the other hand, the upper limit is preferably 85% by mass or less, and more preferably 80% by mass or less. When the saturated content of the first heavy oil is less than 60% by mass, the orientation of the mesophase is deteriorated, and the raw coal has a low crystallinity structure, which is not preferable.
The density of the first heavy oil at 15 ° C. is preferably 0.85 to 0.89 g / cm ³ .

The second heavy oil according to the present invention is a heavy oil having an initial boiling point of 150 ° C. or higher obtained by fluid catalytic cracking of hydrocarbon oil and a sulfur content of 0.5% by mass or less.
Here, “fluid catalytic cracking” means a process of cracking a high-boiling fraction using a solid acid catalyst or the like. The fluid catalytic cracking apparatus used for such treatment is also called an FCC (Fluidized Catalytic Cracking) apparatus.

The hydrocarbon oil that is the raw material oil of the second heavy oil is not particularly limited as long as it can obtain a heavy oil whose initial boiling point and sulfur content satisfy the above conditions by fluid catalytic cracking, A hydrocarbon oil having a density at 15 ° C. of 0.8 g / cm ³ or more is preferred.
Such hydrocarbon oils include straight-run gas oil, vacuum gas oil, desulfurized gas oil, desulfurized vacuum gas oil, atmospheric distillation residual oil, vacuum distillation residual oil, shale oil, tar sand bitumen, orinocotal, coal liquefied oil, Examples include hydrorefined products and mixtures thereof. In the present invention, vacuum gas oil and desulfurized vacuum gas oil are particularly preferably used.

The conditions for fluid catalytic cracking are not particularly limited as long as it is possible to obtain a heavy oil whose initial boiling point and sulfur content satisfy the above conditions. For example, the reaction temperature is 480 to 550 ° C., the total pressure is 1 to 3 kg. / Cm ² G (98 to 294 kPa gauge pressure), catalyst / oil ratio of 1 to 20 wt / wt, and contact time of 1 to 10 seconds are preferable.
Examples of the catalyst used for fluid catalytic cracking include a silica / alumina catalyst, a zeolite catalyst, or a catalyst in which a metal such as platinum is supported on these catalysts. A commercial item may be used for these catalysts.

  The initial boiling point of the second heavy oil thus obtained is required to be 150 ° C. or higher, preferably 200 ° C. or higher, more preferably 220 ° C. or higher. If the initial boiling point is lower than 150 ° C., the yield of raw coal is reduced, and the resulting raw coal has an amorphous structure, and the remaining alkali metal in the activated carbon obtained by alkali activation of the raw coal is obtained. This is not preferable because the amount increases, and the thermal expansion coefficient of needle coke obtained by calcining the raw coal is increased. The upper limit of the initial boiling point is preferably 350 ° C. or lower, more preferably 300 ° C. or lower.

Further, the sulfur content of the second heavy oil needs to be 0.5% by mass or less, preferably 0.4% by mass or less, more preferably 0.3% by mass or less. If the sulfur content exceeds 0.5 mass%, there is a tendency to induce early coking, and the resulting raw coal has a coke structure with poor crystallinity, and the remaining alkali metal in the activated carbon obtained by alkali activation of the raw coal This is not preferable because the amount increases, and puffing of needle coke obtained by calcining the raw coal cannot be sufficiently suppressed.
The nitrogen content of the second heavy oil is not particularly limited, but is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and further preferably 0.1% by mass or less. . When the nitrogen content is more than 0.2% by mass, the needle coke puffing cannot be sufficiently suppressed.

The raw material oil composition of the present invention is preferably obtained by mixing the first heavy oil and the second heavy oil described above. Moreover, the raw material oil composition of the present invention may further contain a vacuum distillation residue oil in addition to the first heavy oil and the second heavy oil.
The above-mentioned vacuum distillation residue oil has an initial boiling point of 300 ° C. or higher obtained as a residual oil when petroleum is distilled under reduced pressure, an asphaltene content of 12 mass% or less, a saturation content of 50 mass% or more, and a sulfur content of 0.3 mass%. The following heavy oils are preferred. Examples of the petroleums include crude oil, vacuum distillation residue obtained by distillation of crude oil, and mixed oils thereof. The treatment conditions when the above petroleums are distilled under reduced pressure are not particularly limited as long as the boiling point, asphaltene content, saturated content and sulfur content of the obtained vacuum distillation residue oil satisfy the above conditions, but the pressure is preferably 30 kPa or less, The temperature is preferably 400 ° C. or higher.

As a mixing ratio of the first heavy oil and the second heavy oil, when the activated carbon used for the electrode material for the electric double layer capacitor is manufactured, the content of the first heavy oil in the obtained raw material oil composition The ratio is preferably 5% by mass or more, more preferably 10% by mass, further preferably 15% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. It mix | blends so that it may become. Moreover, when producing raw material coal for needle coke, the mixing ratio of the first heavy oil and the second heavy oil is preferably 1 to 50% by mass of the first heavy oil. More preferably, it is 5-50 mass%, and it is still more preferable that it is 15-50 mass%.
In the case of a combination of the first heavy oil, the second heavy oil, and the vacuum distillation residue oil, the content of the vacuum distillation residue oil is preferably 10% by mass or more, more preferably 20% by mass or more. More preferably, it is 30% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and still more preferably 50% by mass or less. At this time, the 1st heavy oil and the 2nd heavy oil are blended so that it may become 10 mass% or more, respectively.

Next, the raw material oil composition of the present invention is subjected to coking (carbonization) treatment.
Examples of the method for coking the raw material oil composition include a delayed coking method, a visbreaking method, a flexi coking method, a yurika process, and H-Oil. Among these, the delayed coking method is particularly preferable.
In the delayed coking method, the raw material oil composition is placed in a delayed coker and heat treated under pressure. The pressure of the delayed coker is preferably 300 to 800 kPa. The temperature is preferably 400 to 600 ° C, more preferably 450 to 550 ° C, and the time is preferably 24 to 72 hours, more preferably 36 to 60 hours.
By the coking process, carbide (raw coke) that becomes raw coal is obtained.

When the raw coal of the present invention is graphitized at a temperature of 2800 ° C. in an inert gas atmosphere, the ratio of the crystallite size and the lattice constant of the graphitized material is 360 or less, more preferably 350 or less on the 002 plane. , 110 has a structure of 1500 or less, more preferably 1300 or less.
The sulfur content of the raw coal of the present invention is usually 0.3% by mass or less, and the bulk specific gravity is usually 0.55 or more.
The raw coal of the present invention preferably has a true specific gravity of not less than 2.23, more preferably not less than 2.24 when graphitized at 2800 ° C. in an inert gas atmosphere. . If the true specific gravity is less than 2.23, the crystallites are randomly arranged, and the edge surfaces are closed by the crystallite surfaces.

In the present invention, when the first heavy oil alone or the mixed oil of the first heavy oil and the second heavy oil is heat-treated at 500 ° C., it is 10 μm or less present in the raw coal. The proportion of the mosaic structure is as small as 2% or less, preferably 1% or less. Here, a small proportion of a mosaic structure of 10 μm or less in the raw coal means that the growth state of liquid crystal called mesophase is good. The mesophase is an intermediate product produced by thermal decomposition and polycondensation accompanying heat treatment of the feedstock oil, and a series of aromatic rings developed along the same plane.
The method for measuring the mosaic structure in the raw coal is as described in “Basics of Carbonization Engineering”, Yuzo Sanada and Sugirou Otani (Ohm), page 147.

  Conventionally, when a raw material oil contains a large amount of a saturated component, particularly an aliphatic component, a crosslinking reaction occurs in addition to the polymerization and polycondensation of aromatic components during coking, so that a three-dimensional crystal grows and the mesophase is sufficient. It is considered that the structure does not grow and the crystallinity is inferior, and as a result, the coefficient of thermal expansion of needle coke is considered to increase, and the amount of residual alkali metal in the activated carbon is considered to increase. In view of this point, even if the saturation content of the first heavy oil is 50% by mass or more, a mosaic structure of 10 μm or less does not exist at all, or even if present, coking coal having 2% or less is obtained. That is a surprising result.

The raw coal obtained by the coking process can be converted into activated carbon by an alkali activation treatment. Moreover, in carrying out the alkali activation treatment, it is also preferably employed that the raw coal is heat treated at 550 to 900 ° C., preferably 600 to 850 ° C. under an inert atmosphere and normal pressure, and then subjected to the alkali activation treatment.
In the present invention, the activated carbon thus obtained is used as an electrode material for an electric double layer capacitor.

  As a method for activating the raw coal or the raw material for heat treatment of raw material carbon, an activation furnace is used to heat the raw material coal or the raw material for heat treatment of raw material coal at 500 to 1200 ° C. together with a metal hydroxide in an atmosphere of nitrogen gas or inert gas. A method can be mentioned. Specific examples of the metal hydroxide include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide, and alkaline earth metal hydroxides such as magnesium hydroxide and barium hydroxide. be able to. Moreover, not only 1 type but 2 or more types can also be used in combination. Of these, potassium hydroxide is particularly preferable because it can efficiently form micropores.

The amount of the raw coal or raw material heat treated carbon and metal hydroxide can be 1 / 0.5 to 1/10 in the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide, Preferably it is 1/1 to 1/5.
By setting the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide to 1 / 0.5 or less, it is possible to sufficiently form micropores in the activated carbon and obtain activated carbon having a sufficient surface area. it can. Moreover, by making the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide to 1/10 or more, the activation reaction can be efficiently performed without lowering the bulk density.
In addition, in the activation reaction, water or the like may coexist in addition to the raw coal or the raw material heat-treated with the raw coal and the metal hydroxide.

In the activation of the raw coal or the raw material for heat treatment of raw coal, the activation temperature may be, for example, in the range of 500 to 1200 ° C, preferably 600 to 1000 ° C, more preferably 600 to 800 ° C. Can do. When the activation temperature is in the above range, activated carbon having sufficient fine pores can be obtained efficiently. The activation treatment time can be appropriately selected in relation to conditions such as temperature, and can include 3 to 6 hours, for example.
Examples of the inert gas at the time of activation include inert gas and nitrogen gas. For example, it is preferable to supply such that the oxygen concentration in the activation atmosphere can be maintained at 100 ppm by volume or less.

The cleaning of the activated material is a cleaning in which the activated material is washed with a cleaning liquid to perform solid-liquid separation. The activated material is immersed in the cleaning liquid and mixed with the cleaning liquid by stirring and heating as necessary, and then the cleaning liquid is removed. The method of doing can be mentioned. As the cleaning liquid, water and an aqueous acid solution are preferably used. For example, cleaning with water, cleaning with an aqueous acid solution, and further cleaning with water can be used in appropriate combination. Preferred examples of the acid aqueous solution include hydrohalic acids such as hydrochloric acid, hydroiodic acid, and hydrobromic acid, and inorganic acids such as sulfuric acid and carbonic acid. Examples of the concentration of the acid aqueous solution include 0.01 to 3N. Cleaning with these cleaning liquids can be repeated a plurality of times as necessary.
After the final washing of the washing step using the washing liquid, solid-liquid separation is performed from the washing liquid, and heating, air drying, and the like are performed as appropriate to remove moisture and obtain dried activated carbon.

The activated carbon obtained by alkali activation of the raw coal or raw material heat treated carbon of the present invention has a feature that the residual alkali metal is reduced when washed by the same washing operation as compared with the conventional activated carbon. The reason why the residual alkali metal is reduced is that the raw coal and the raw material heat-treated with the coal according to the present invention have a crystal structure in which the metal hydroxide of the activator can easily enter and escape, and the obtained activated carbon This is considered to be due to the crystal structure that makes it easy for the cleaning liquid to enter and escape.
In addition to this, when the activated carbon according to the present invention is used for an electrode of an electric double layer capacitor, it is easy for electrolyte ions to enter and exit during charge and discharge, and the capacitance retention rate in the cycle characteristic test is improved. .
The electric double layer capacitor of the present invention uses activated carbon obtained from the raw coal of the present invention or a heat-treated product of raw coal as an electrode material.

The electrode of the electric double layer capacitor of the present invention is not particularly limited as long as it contains the above activated carbon, but may contain a binder, a conductive agent, etc., and is integrated with the current collector. It may be what you did.
As the binder, known ones can be used, and specifically, fluorinations such as polyolefins such as polyethylene and polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, and fluoroolefin / vinyl ether copolymer cross-linked polymers. Examples thereof include polymers, celluloses such as carboxymethyl cellulose, vinyl polymers such as polyvinyl pyrrolidone and polyvinyl alcohol, and polyacrylic acid. Specifically, the content of the binder in the electrode material may be 0.1 to 30% by mass.
Specific examples of the conductive agent include powders such as carbon black, acetylene black, and powdered graphite. As content in the electrode material of a electrically conductive agent, the range of 1-50 mass% is preferable, More preferably, it is 2-30 mass%.

In order to produce an electrode using these materials, for example, a method of adding the activated carbon, the binder, and a conductive agent to a solvent that dissolves the binder and applying the slurry as a slurry to a sheet-like current collector, Examples thereof include a method in which the activated carbon, the binder, and the conductive agent are kneaded without using a solvent and pressure-molded at room temperature or under heating.
As the current collector, known materials and shapes can be used, and specific examples include metals such as aluminum, titanium, tantalum, and nickel, and alloys such as stainless steel.
The electric double layer capacitor of the present invention can be produced as a unit cell in which a pair of electrodes are provided with a positive electrode and a negative electrode facing each other through a separator and immersed in an electrolyte solution. As the separator, unemployed cloth made of polypropylene fiber or glass fiber, cellulose paper, or the like can be used.

As the electrolytic solution, an aqueous electrolytic solution or a non-aqueous electrolytic solution can be used, but it is preferable to use a non-aqueous electrolytic solution. Examples of the non-aqueous electrolyte include those obtained by dissolving an electrolyte in an organic solvent. Specific examples of the solvent include propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, sulfolane, and 3-methylsulfolane. Such as sulfolane derivatives, 1,2-dimethoxyethane, etc., dimethoxyethane, acetonitrile, glutaronotolyl, valeronitrile, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, methyl formate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, etc. Can be used alone or in combination of two or more. Examples of the electrolyte of the electrolytic solution include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, cyclic quaternary ammonium salts, and quaternary phosphonium salts. _{C 2 H 5) 4 NBF 4} , (C 2 H 5) 3 (CH 3) NBF 4, (C 2 H 5) 4 PBF 4, (C 2 H 5) 3 (CH 3) PBF 4 and the like Can do. The electrolyte concentration in the electrolytic solution can be 0.1 to 5 mol / L, and preferably 0.5 to 5 mol / L.

As the shape of the electric double layer capacitor of the present invention, for example, a coin type and a pair of electrodes in which a pair of electrodes of a sheet shape or a disk shape having a thickness of 50 to 500 μm are housed in a metal case via a separator. Examples thereof include a wound type wound through a separator, and a laminated type in which a pair of electrodes provided via a separator are provided in multiple layers.
In the electric double layer capacitor of the present invention, since the activated carbon is used as an electrode material, cycle characteristics are improved, and excellent durability and excellent capacity retention are exhibited.

Moreover, the above-described raw coal of the present invention can be made into needle coke by further calcination in a rotary kiln, a shaft furnace or the like. The temperature during calcination is preferably 800 to 1600 ° C, more preferably 1000 to 1500 ° C. The calcination time is usually 1 to 10 hours, preferably 2 to 6 hours.
The needle coke of the present invention preferably has a sulfur content of 0.5% by mass or less, a nitrogen content of 0.1% by mass or less, and a bulk specific gravity of 0.82 or more.
The needle coke of the present invention has a coefficient of thermal expansion that is sufficiently small and puffing is sufficiently suppressed.
As a method for suppressing puffing, the use of an anti-puffing agent (puffing inhibitor) is conventionally known. In this method, the anti-puffing agent becomes an impurity and the quality of the electrode (especially thermal expansion coefficient, density, etc.) May be adversely affected. In contrast, the needle coke of the present invention is very useful in that puffing can be sufficiently suppressed without using an anti-puffing agent and the thermal expansion coefficient of the needle coke can be sufficiently reduced.

  The needle coke of the present invention is suitably used as an aggregate of a graphite electrode for electric steelmaking. As a method for producing a graphite electrode product using the needle coke of the present invention, a raw material obtained by adding an appropriate amount of binder pitch to the needle coke of the present invention is heated and mixed, and then extruded to obtain a raw electrode. The method of processing after baking and graphitizing an electrode is mentioned.

  In the present invention, “sulfur content” means a value measured in accordance with JIS K2541 in the case of oil, and a value measured in accordance with JIS M 8813 in the case of coke. The “nitrogen content” means a value measured according to JIS K 2609 in the case of oil, and a value measured according to JIS M 8813 in the case of coke. Further, “saturated content” and “asphaltene content” mean values measured using a thin layer chromatograph.

  The raw coal of the present invention is suitably used for producing activated carbon for electric double layer capacitor electrodes and also for producing needle coke.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example and a comparative example, this invention is not limited to a following example.

<Example 1>
(1) Preparation of raw material oil composition Hydrodesulfurization of middle-eastern atmospheric distillation residue having a sulfur content of 2.5% by mass in the presence of a Ni-Mo catalyst so that the hydrocracking rate is 25% or less. Thus, desulfurized heavy oil (hereinafter referred to as “hydrodesulfurized oil A”) was obtained. The hydrodesulfurization conditions were a total pressure of 22 MPa, a hydrogen partial pressure of 20 MPa, a temperature of 380 ° C., a hydrogen / oil ratio of 590 NL / L, and a liquid space velocity (LHSV) of 0.17 h ⁻¹ .
Also, using a vacuum distillation residual oil and desulfurized vacuum gas oil as raw material, a catalyst in which platinum (Pt) is supported on silica / alumina, a reaction temperature of 520 ° C., a total pressure of 0.2 MPa, a catalyst / oil ratio of 7, contact A fluid catalytic cracking residual oil (hereinafter referred to as “fluid catalytic cracking residual oil A”) was obtained at a time of 3 seconds.
Subsequently, the hydrodesulfurized oil A and the fluid catalytic cracking residual oil A were mixed at a mass ratio of 5: 5 to obtain a raw material oil composition A.

(2) Preparation of raw coal Next, the raw oil composition A was subjected to coking treatment at 500 ° C. under nitrogen and 400 kPa for 40 hours to obtain coke (raw coal A). This raw coal A was heat-treated at 2800 ° C. under nitrogen to obtain a graphitized product. Table 1 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.

(3) Activation of raw coal Coal 1 part by mass of raw coal A and 2.5 parts by weight of potassium hydroxide (KOH) are mixed, put into a nickel reaction vessel, heated at 700 ° C. for 1 hour under nitrogen, and activated. Went.
After the activation treatment, the reaction mixture inside the reaction vessel was cooled to 250 ° C., and carbon dioxide was flowed in place of nitrogen to deactivate the metal potassium. Thereafter, 20 kg of water was added to 2 kg of the reaction product, stirred at room temperature for 1 hour, and filtered under pressure. This operation was performed twice. Subsequently, 20 kg of 0.3N hydrochloric acid solution was added, stirred for 3 hours, and filtered under pressure. An additional 20 kg of water was added, and the mixture was stirred for 1 hour and filtered under pressure. This operation was also performed twice. The obtained solid was dried at 130 ° C. to obtain activated carbon for an electric double layer capacitor electrode. Table 2 shows the specific surface area, residual potassium amount and true specific gravity of the activated carbon.

(4) Production of electric double layer capacitor Activated carbon (0.8 g), Ketjen black (0.1 g) and polytetrafluoroethylene (0.1 g) obtained above were mixed in a mortar. This mixture was sandwiched between two 0.1 mm thick triacetate films and rolled by passing 20 times between nip rolls having a width of 160 mm, an upper and lower roll interval of 0.7 mm, and a pressure of 23.0 MPa. Two circles having a diameter of 16 mm were punched out from the rolled sheet to obtain carbon electrodes. The carbon electrode was dried in a vacuum dryer for 2 hours.
A cellulose separator having a thickness of 50 μm is sandwiched between two electrodes impregnated with an electrolytic solution (one mole of (C ₂ H ₅ ) ₃ (CH ₃ ) NBF ₄ dissolved in 1 liter of propylene carbonate) It was enclosed in a SUS316 coin cell having a diameter of 20 mm. In this case, a current collector carbon coating applied to the surface of a 20 μm thick aluminum foil was used as a current collector, and the paint side was sandwiched between the carbon electrode and the cell so as to face the carbon electrode.
Table 2 shows the capacitance and cycle characteristics (capacitance retention rate after 1000 charge / discharge cycles) of the electric double layer capacitor cell thus fabricated.

<Example 2>
An atmospheric distillation residue having a sulfur content of 3.0% by mass was distilled under reduced pressure at a heating furnace outlet temperature of 360 ° C. and a pressure of 1.3 kPa, an initial boiling point of 410 ° C., an asphaltene content of 8% by mass, and a saturation content of 50%. % Distillation residue oil A having a sulfur content of 0.1% by mass and a nitrogen content of 0.3% by mass was obtained.
Subsequently, the composition of the hydrodesulfurized oil A and the fluid catalytic cracking residual oil A of Example 1 was mixed so that the above-mentioned reduced-pressure distillation residue oil A was 30% by mass to obtain a raw material oil composition B.
Next, the raw material oil composition B was subjected to coking treatment at 500 ° C. for 40 hours under nitrogen and 400 kPa to obtain coke (raw coal B). This raw coal B was heat-treated at 2800 ° C. under nitrogen to obtain a graphitized product. Table 1 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
An activation reaction and a capacitor were produced in the same manner as in Example 1 except that the raw coal B was used instead of the raw coal A. Table 2 shows the specific surface area of the activated carbon, the amount of residual potassium and the true specific gravity, and the capacitance and cycle characteristics of the capacitor cell (capacitance retention rate after 1000 charge / discharge cycles).

<Comparative Example 1>
The fluid catalytic cracking residual oil A used in Example 1 was subjected to coking treatment under nitrogen and 400 kPa at 500 ° C. for 40 hours to obtain coke. The coke was then heat treated at 2800 ° C. under nitrogen. Table 1 shows the X-ray diffraction measurement results (Gakushin 117 committee) of this heat-treated product. Further, the specific surface area, the residual potassium amount and the true specific gravity of the activated carbon obtained by alkali activation of the coke under the conditions of Example 1, and the capacitance and cycle characteristics of the capacitor cell (static capacity after 1000 charge / discharge cycles) Table 2 shows the retention rate of electric capacity.

<Comparative example 2>
The vacuum distillation residue oil A used in Example 2 was subjected to coking treatment under nitrogen, 400 kPa, and 500 ° C. for 40 hours to obtain coke. The coke was then heat treated at 2800 ° C. under nitrogen. Table 1 shows the X-ray diffraction measurement results (Gakushin 117 committee) of this heat-treated product. Further, the specific surface area, the residual potassium amount and the true specific gravity of the activated carbon obtained by alkali activation of the coke under the conditions of Example 1, and the capacitance and cycle characteristics of the capacitor cell (static capacity after 1000 charge / discharge cycles) Table 2 shows the retention rate of electric capacity.

  From Table 1 and Table 2, when the ratio of the crystallite size and the lattice constant on the 002 and 110 planes of the 2800 ° C. heat-treated product is 360 or less on the 002 plane and 1500 or less on the 110 plane, it is obtained by activation with KOH. The amount of potassium remaining in the obtained activated carbon is small, and the cycle characteristics of the electric double layer capacitor obtained by using such activated carbon, that is, the retention rate of the capacitance after repeating 1000 times of charge and discharge It is clear that the capacitor characteristics are excellent.

<Example 3>
(1) Preparation of raw material oil composition First, hydrodesulfurization of atmospheric distillation residue having a sulfur content of 3.5% by mass in the presence of a Ni-Mo catalyst so that the hydrocracking rate is 30% or less. A desulfurized heavy oil (hereinafter referred to as “hydrodesulfurized oil B”) was obtained. The hydrodesulfurization conditions were a total pressure of 18.5 MPa, a hydrogen partial pressure of 16.5 MPa, a temperature of 370 ° C., a hydrogen / oil ratio of 590 NL / L, and a liquid space velocity (LHSV) of 0.17 h ⁻¹ . The obtained hydrodesulfurized oil B has an initial boiling point of 260 ° C., a sulfur content of 0.3% by mass, a nitrogen content of 0.1% by mass, an asphaltene content of 2% by mass, and a saturated content of 70% by mass. there were.
This hydrodesulfurized oil B was put in a test tube and heat-treated at normal pressure and 500 ° C. for 3 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, a mosaic structure of 10 μm or less was not observed.
Further, desulfurized vacuum gas oil (sulfur content: 500 mass ppm, density: 0.88 g / cm ^{3 at} 15 ° C.) is subjected to fluid catalytic cracking to obtain fluid catalytic cracking residual oil (hereinafter referred to as “fluid catalytic cracking residual oil B”). It was. The initial boiling point of the obtained fluid catalytic cracking residual oil B is 210 ° C., the sulfur content is 0.1% by mass, the nitrogen content is 0.1% by mass, the asphaltene content is 0% by mass, and the saturation content is 30% by mass. Met.
This fluid catalytic cracking residual oil B was put in a test tube and heat-treated at normal pressure and 500 ° C. for 3 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized.

(2) Preparation of raw coal Next, hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 2: 8 to obtain raw oil composition C. This raw material oil composition C was subjected to heat treatment at 400 ° C. for 40 hours at 400 ° C. to be coke to obtain coke (raw coal C). When this raw carbon C was embedded in a commercially available resin and observed with a polarizing microscope, a mosaic structure of 10 μm or less was not recognized.

(3) Activation of raw coal Coal 1 part by mass of raw coal C and 2.5 parts by mass of potassium hydroxide (KOH) are mixed, put into a nickel reaction vessel, heated at 750 ° C. for 1 hour under nitrogen, and activated. Processed.
After the activation treatment, the reaction mixture inside the reaction vessel was cooled to 300 ° C., and carbon dioxide was passed instead of nitrogen to deactivate the metal potassium. Thereafter, 20 kg of water was added to 2 kg of the reaction product, stirred at room temperature for 1 hour, and filtered under pressure. This operation was performed twice. Subsequently, 20 kg of 0.3N hydrochloric acid was added, stirred for 3 hours, and filtered under pressure. An additional 20 kg of water was added, and the mixture was stirred for 1 hour and filtered under pressure. This operation was also performed twice. The obtained solid was dried at 130 ° C. to obtain activated carbon for an electric double layer capacitor. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon.

(4) Production of electric double layer capacitor An electric double layer capacitor was produced in the same manner as in Example 1 except that the activated carbon obtained above was used. Table 3 shows the capacitance and cycle characteristics (capacitance retention rate after 1000 charge / discharge cycles) of the electric double layer capacitor cell thus fabricated.

<Example 4>
The hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 8: 2 to obtain a raw material oil composition D. This raw material oil composition D was subjected to heat treatment at 400 ° C. for 40 hours at 500 ° C. to be coke to obtain coke (raw coal D). Except that 1 part by mass of raw coal D and 2.5 parts by mass of potassium hydroxide (KOH) were mixed, put in a nickel reaction vessel, heated at 750 ° C. for 1 hour under nitrogen, and subjected to activation treatment, The same operation as in Example 3 was performed to obtain activated carbon for an electric double layer capacitor. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon. Moreover, the electric double layer capacitor was produced by the same operation as Example 1 using the said activated carbon. Table 3 shows the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of capacitance after repeating charge and discharge 1000 times).

<Comparative Example 3>
Only the fluid catalytic cracking residual oil B obtained in Example 3 was heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke, and then subjected to alkali activation treatment in the same manner as in Example 3 to obtain An electric double layer capacitor was fabricated using activated carbon. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon, and the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of the capacitance after repeating charge and discharge 1000 times).

<Comparative example 4>
An atmospheric distillation residue (density 0.92 g / cm ³ , sulfur content 0.35 mass%) was distilled under reduced pressure under conditions of a heating furnace outlet temperature of 350 ° C. and a pressure of 1.3 kPa to obtain an initial boiling point of 410 ° C. and asphaltene. A vacuum distillation residue oil (hereinafter referred to as “vacuum distillation residue oil B”) having a content of 9% by mass, a saturation content of 61% by mass and a sulfur content of 0.1% by mass was obtained. The reduced-pressure distillation residue oil B is heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke, and then subjected to an alkali activation treatment in the same manner as in Example 3, and the obtained activated carbon is used for an electric double layer capacitor. Was made. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon, and the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of the capacitance after repeating charge and discharge 1000 times).

  As is apparent from Table 3, the amount of potassium remaining in the obtained activated carbon is greatly reduced by using the raw material oil composition of the present invention obtained by mixing hydrodesulfurized oil and fluid catalytic cracking residual oil. As a result, the electrostatic capacity retention rate of the electric double layer capacitor using the same can be improved.

<Example 5>
The hydrodesulfurized oil B and fluid catalytic cracking residual oil B used in Example 3 were mixed at a mass ratio of 1: 3 to obtain a raw material oil composition E. This raw material oil composition E was put into a test tube and heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke to obtain coke (raw coal E). When this raw coal E was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized. Further, the raw coal E was heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain a graphitized product. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the raw coal E was calcined at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
Further, 30% by mass of a coal-based binder pitch was added to calcined coke, and a cylindrical piece was produced with an extruder. This piece was fired at 1000 ° C. for 1 hour using a muffle heating furnace, and the thermal expansion coefficient after firing was measured. Furthermore, the piece was heat-treated from room temperature to 2800 ° C., and the degree of expansion in this process was measured as puffing. The results obtained are shown in Table 5.

<Example 6>
Hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 1: 5 to prepare a feed oil composition F. This raw material oil composition F was put in a test tube and heat-treated at 400 ° C. and 500 ° C. for 40 hours to be coke to obtain coke (raw coal F). When this raw carbon F was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized. Further, the raw coal E was heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain a graphitized product. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the raw coal F was calcined at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.

<Comparative Example 5>
The fluid catalytic cracking residual oil B was put into a test tube and heat treated at 500 ° C. under 400 kPa for 40 hours to be coke. Moreover, this coke was heat-processed at 2800 degreeC by nitrogen atmosphere, and the graphitized material was obtained. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.

<Comparative Example 6>
A low-sulfur crude oil having a sulfur content of 0.2% by mass, a nitrogen content of 0.3% by mass and a saturation content of 40% by mass was distilled under reduced pressure to obtain a vacuum distillation residue oil (hereinafter referred to as “vacuum distillation residue oil C”). . This vacuum distillation residue oil C was put into a test tube and heat-treated at 400 ° C. and 500 ° C. for 40 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the mosaic structure of 10 μm or less was 18%. Moreover, this coke was heat-processed at 2800 degreeC by nitrogen atmosphere, and the graphitized material was obtained. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.

<Comparative Example 7>
The vacuum distillation residual oil C and fluid catalytic cracking residual oil B were mixed at a mass ratio of 1: 1 to prepare a raw material oil composition. This raw material oil composition was put into a test tube and heat-treated at 500 ° C. under 400 kPa for 40 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the mosaic structure of 10 μm or less was 5%. Moreover, this coke was heat-processed at 2800 degreeC by nitrogen atmosphere, and the graphitized material was obtained. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.

<Comparative Example 8>
The vacuum distillation residue oil C and fluid catalytic cracking residue oil B were mixed at a mass ratio of 1: 5 to prepare a raw material oil composition. This raw material oil composition was put into a test tube and heat-treated at 500 ° C. under 400 kPa for 40 hours to be coke. The coke was heat-treated at 2800 ° C. in a nitrogen atmosphere to obtain a graphitized product. Table 4 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
Next, the produced coke was fired at 1000 ° C. for 5 hours to obtain calcined coke. Table 5 shows the sulfur content, nitrogen content and bulk specific gravity of the obtained calcined coke.
A cylindrical piece was produced in the same manner as in Example 5 except that this calcined coke was used, and the thermal expansion coefficient and puffing were measured. The results are shown in Table 5.

The present invention relates to a power storage for carbon material YoHara fee charcoal. In particular, the present invention relates to a raw coal that provides activated carbon from which residual alkali metals can be easily removed as activated carbon for an electric double layer capacitor electrode.

Recently, carbon materials have been widely used in a charge reservoir field. As such a carbon material for power storage, for example, activated carbon having a relatively large surface area is used for an electrode of an electric double layer capacitor, and coke having a relatively small surface area is used as a negative electrode of a lithium ion secondary battery. Yes. In particular, electric double layer capacitors are attracting attention as backup power supplies, auxiliary power supplies, etc., and development focusing on the performance of activated carbon as an electrode for electric double layer capacitors has been widely made. Electric double layer capacitors using activated carbon as a polarizable electrode are excellent in electrostatic capacity, so that demand for electric device electrode applications and the like is growing rapidly with the development of the electronics field. Recently, in addition to the miniaturization of conventional memory backup power supplies, development of large-capacity products that can be used for auxiliary power supplies such as motors has been carried out.
As a method for producing these activated carbons, the carbonaceous material is subjected to a gas activation treatment or a chemical activation treatment, for example, an alkali activation treatment using an alkali metal hydroxide as an activation aid, and then an alkali metal or heavy metal from the activation treatment product. In order to remove water, neutralization washing with a strong acid such as hydrochloric acid, nitric acid or sulfuric acid is generally performed.

  With the demand for higher performance of electric double layer capacitors, there is a need to further reduce the residual alkali metal in activated carbon for electric double layer capacitor electrodes. However, as described in Patent Document 1 (Japanese Patent Laid-Open No. 2005-123462), even if the alkali metal can be removed up to a certain level by repeated washing with water and pickling, it is difficult to remove it further. . For this reason, an electric double layer capacitor using a carbon material after alkali activation has an initial capacitor capacity, but has a problem of deterioration over time such that the capacitor capacity greatly decreases when used for a long time.

On the other hand, from the viewpoint of the cleaning operation, the cleaning operation is as simple as possible, that is, it is desirable that the number of times of cleaning is as small as possible in terms of cost. In Patent Document 2 (International Publication No. 2004-011371 pamphlet), an easily activated graphitized carbonaceous material is subjected to an alkali activation treatment, and the obtained activation treatment product is used as hot water, carbonated water, hot hydrochloric acid, aqueous ammonia, hot hydrochloric acid. In addition, although it is described that activated carbon is obtained by washing in order of hot water, since the washing operation is complicated, development of activated carbon having a structure in which residual alkali metal is easily removed has been strongly desired.
JP 2005-123462 A International Publication No. 2004-011371 Pamphlet

The inventors of the present invention have activated carbon obtained by alkali activation of raw coal having a specific structure, which makes it easy for the cleaning liquid to enter and exit during cleaning, and as a result, can reduce the residual alkali content in the activated carbon, It was found that the washing operation can be simplified.
Note that the "coking coal" in the present invention, a feedstock such as heavy oil and residual oil obtained by coking processes, refers to a carbide as a raw material for activated carbon.

That is, the present invention has a structure in which the ratio between the crystallite size and the lattice constant of graphitized material when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. about charcoal YoHara charge coal for an electric double layer capacitor characterized by having a.

  In addition, the present invention provides an initial boiling point of 200 ° C. or higher obtained by hydrodesulfurization of a heavy oil having a sulfur content of 2% by mass or more under a condition of a total pressure of 16 MPa or more so that the hydrocracking rate is 30% or less. And a second heavy oil having an initial boiling point of 150 ° C. or higher and a sulfur content of 0.5% by mass or less obtained by fluid catalytic cracking of hydrocarbon oil. The present invention relates to a raw material oil composition for producing the raw coal.

  Moreover, this invention relates to the manufacturing method of the said raw coal characterized by coking the said raw material oil composition at 300-800 kPa and 400-600 degreeC.

  The present invention also relates to activated carbon obtained by activating the raw coal or the raw coal heat-treated product obtained by heat-treating the raw coal at 550 to 900 ° C. under normal pressure with an alkali metal hydroxide.

  The present invention also relates to an electric double layer capacitor using the activated carbon as an electrode material.

  The activated carbon obtained by alkali activation of the raw coal of the present invention is easy for the cleaning solution to enter and exit, and as a result, the amount of remaining alkali metal is reduced even in the same cleaning operation, so the cycle of the electric double layer capacitor using it as an electrode material Improved characteristics. Moreover, since the washing operation is simplified, the activated carbon can be manufactured at a lower cost, and its industrial value is extremely large.

Hereinafter, the present invention will be described in detail.
In the raw coal of the present invention, the ratio of the crystallite size and the lattice constant of the graphitized product when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. Gives structure. When the ratio of the crystallite size to the lattice constant on the 002 plane exceeds 360, or the ratio of the crystallite size to the lattice constant on the 110 plane exceeds 1500, the ratio of the edge plane to the crystallite of the raw coal is For this reason, it is considered that the amount of potassium remaining in the activated carbon increases because the cleaning solution cannot enter the crystallites through the edge surface and the cleaning effect is reduced.
Here, the interlayer distance d ₀₀₂ (lattice constant) of the microcrystalline carbon and the crystallite size Lc ₀₀₂ of the microcrystalline carbon were determined by the Japan Society for the Promotion of Science 117th Committee, “Lattice constant and crystallite of artificial graphite” In accordance with the “size measurement method”, the X-ray diffraction method is used as follows.

That is, sample powder (one obtained by graphitizing raw coal at 2800 ° C.) is filled in a sample holder, and an X-ray diffraction pattern is obtained using CuKα rays monochromatized by a graphite monochromator as a radiation source. The peak position of the diffraction pattern is obtained by the centroid method (a method of obtaining the centroid position of the diffraction line and obtaining the peak position using the corresponding 2θ value), and the diffraction peak of the (111) plane of the high-purity silicon powder for standard materials. Use to correct. Then, the wavelength of the CuKα ray is set to 0.15418 nm, and the interlayer distance d ₀₀₂ of microcrystalline carbon is calculated by the Bragg formula expressed by the following formula (1).
d ₀₀₂ = λ / (2 sin θ) (1)

The presence or absence of formation of the graphite structure in the sample can be confirmed, for example, by having a clear peak at 2θ of about 25 ° in the powder X-ray diffraction pattern of the sample. That is, graphite has a stacked structure of layers having a planar network structure of so-called benzene ring, as measured by powder X-ray diffraction, diffraction peak based on C ₀₀₂ is sharply interlayer distance d _{002 =} 0.335 nm It is observed as a sharp peak (2θ is about 25 °). Further, the half width (β) is measured from the diffraction line pattern, and the size of the crystallite is obtained by the following formula (2).
Lc ₀₀₂ = 91 / β (2)

When the raw coal of the present invention is heat-treated at 2800 ° C., the X-ray diffraction pattern is compared, which is very close to the structure of graphite.
In the present invention, the raw material oil and the production method thereof are not particularly limited as long as the raw coal satisfying the above conditions is obtained. However, the raw material oil is preferably hydrodesulfurized oil, fluid catalytic cracking obtained in the petroleum refining process. A raw material oil composition obtained by blending at least two raw material oils selected from residual oil and vacuum distillation residue oil is preferred.

  As the raw material oil composition in the present invention, in particular, a heavy oil having specific properties (hereinafter referred to as a first heavy oil) obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more. What consists of a mixture of the heavy oil (henceforth a 2nd heavy oil) which has the specific property obtained by the fluid catalytic cracking of hydrocarbon oil is preferable.

The first heavy oil according to the present invention is obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more so that the hydrocracking rate is 30% or less under the condition of a total pressure of 16 MPa or more. It is a heavy oil with an initial boiling point of 200 ° C. or higher.
As described above, the sulfur content of the heavy oil used as the raw material oil for the first heavy oil is 2% by mass or more, preferably 2.5% by mass or more, and more preferably 3% by mass or more. Although an upper limit is not specifically limited, 5 mass% or less is preferable, More preferably, it is 4 mass% or less.
The heavy oil used as the first heavy oil feedstock is not particularly limited as long as the sulfur content satisfies the above conditions. For example, crude oil, atmospheric distillation residue obtained by distillation of crude oil, or reduced pressure Examples include distillation residual oil, visbreaking oil, tar sand oil, shale oil, and mixed oils thereof. Among these, atmospheric distillation residue and vacuum distillation residue are preferably used.

The hydrodesulfurization for obtaining the first heavy oil is performed under conditions of a total pressure of 16 MPa or more, preferably 17 MPa or more, more preferably 18 MPa or more. When the total pressure is less than 16 MPa, the heavy oil is excessively decomposed by hydrodesulfurization, and a heavy oil suitable as a raw oil composition for obtaining the raw coal of the present invention cannot be obtained. Although an upper limit is not specifically limited, 25 Mpa or less is preferable, More preferably, it is 22 Mpa or less.
The conditions other than the total pressure in hydrodesulfurization are not particularly limited as long as the hydrocracking rate is 30% or less, but it is preferable to set various conditions as follows. That is, the hydrodesulfurization temperature is preferably 300 to 500 ° C., more preferably 350 to 450 ° C., and the hydrogen / oil ratio is preferably 400 to 3000 NL / L, more preferably 500 to 1800 NL / L. The hydrogen partial pressure is preferably 7 to 20 MPa, more preferably 8 to 17 MPa, and the liquid space velocity (LHSV) is preferably 0.1 to 3 h ⁻¹ , more preferably 0.15 to 1.0 h ^{−. 1} and more preferably 0.15 to 0.75 h- ¹ .
Moreover, as a catalyst (hydrodesulfurization catalyst) used for hydrodesulfurization, a Ni-Mo catalyst, a Co-Mo catalyst, the catalyst which combined both, etc. are mentioned, These may use a commercial item.

Of the hydrodesulfurized oil obtained by the above hydrodesulfurization, a heavy oil having an initial boiling point of 200 ° C. or higher, preferably 250 ° C. or higher is used as the first heavy oil. The upper limit of the initial boiling point is not particularly limited, but is preferably 450 ° C. or lower, more preferably 400 ° C. or lower.
Further, the sulfur content of the first heavy oil is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, further preferably 0.35% by mass or less, and particularly preferably 0.3% by mass. % By mass or less, most preferably 0.25% by mass or less. When the sulfur content of the first heavy oil exceeds 0.5% by mass, it tends to induce early coking, and as a result, the resulting raw coal has a structure with low crystallinity, and the raw coal is activated with alkali. remaining alkali metal in the resulting activated carbon Te is to become many have an unwanted.

The asphaltene content of the first heavy oil is preferably 5% by mass or less, more preferably 4% by mass or less, and still more preferably 3% by mass or less. When the asphaltene content of the first heavy oil exceeds 5% by mass, early coking is promoted, and as a result, the resulting raw coal has a structure with low crystallinity, and the activated carbon obtained by alkali activation of the raw coal the remaining alkali metal is for not an unwanted number.
The saturated content of the first heavy oil is preferably 60% by mass or more, more preferably 65% by mass or more, and further preferably 70% by mass or more. On the other hand, the upper limit is preferably 85% by mass or less, and more preferably 80% by mass or less. When the saturated content of the first heavy oil is less than 60% by mass, the orientation of the mesophase is deteriorated, and the raw coal has a low crystallinity structure, which is not preferable.
The density of the first heavy oil at 15 ° C. is preferably 0.85 to 0.89 g / cm ³ .

The second heavy oil according to the present invention is a heavy oil having an initial boiling point of 150 ° C. or higher obtained by fluid catalytic cracking of hydrocarbon oil and a sulfur content of 0.5% by mass or less.
Here, “fluid catalytic cracking” means a process of cracking a high-boiling fraction using a solid acid catalyst or the like. The fluid catalytic cracker used for such treatment is FCC (Fluidized Catalytic
Also called cracking device.

The hydrocarbon oil that is the raw material oil of the second heavy oil is not particularly limited as long as it can obtain a heavy oil whose initial boiling point and sulfur content satisfy the above conditions by fluid catalytic cracking, A hydrocarbon oil having a density at 15 ° C. of 0.8 g / cm ³ or more is preferred.
Such hydrocarbon oils include straight-run gas oil, vacuum gas oil, desulfurized gas oil, desulfurized vacuum gas oil, atmospheric distillation residual oil, vacuum distillation residual oil, shale oil, tar sand bitumen, orinocotal, coal liquefied oil, Examples include hydrorefined products and mixtures thereof. In the present invention, vacuum gas oil and desulfurized vacuum gas oil are particularly preferably used.

The conditions for fluid catalytic cracking are not particularly limited as long as it is possible to obtain a heavy oil whose initial boiling point and sulfur content satisfy the above conditions. For example, the reaction temperature is 480 to 550 ° C., the total pressure is 1 to 3 kg. / Cm ² G (98 to 294 kPa gauge pressure), catalyst / oil ratio of 1 to 20 wt / wt, and contact time of 1 to 10 seconds are preferable.
Examples of the catalyst used for fluid catalytic cracking include a silica / alumina catalyst, a zeolite catalyst, or a catalyst in which a metal such as platinum is supported on these catalysts. A commercial item may be used for these catalysts.

The initial boiling point of the second heavy oil thus obtained is required to be 150 ° C. or higher, preferably 200 ° C. or higher, more preferably 220 ° C. or higher. If the initial boiling point is lower than 150 ° C., the yield of raw coal is reduced, and the resulting raw coal has an amorphous structure, and the remaining alkali metal in the activated carbon obtained by alkali activation of the raw coal is obtained. the amount is more preferably not name. The upper limit of the initial boiling point is preferably 350 ° C. or lower, more preferably 300 ° C. or lower.

Further, the sulfur content of the second heavy oil needs to be 0.5% by mass or less, preferably 0.4% by mass or less, more preferably 0.3% by mass or less. If the sulfur content exceeds 0.5 mass%, there is a tendency to induce early coking, and the resulting raw coal has a coke structure with poor crystallinity, and the residual alkali metal in the activated carbon obtained by alkali activation of the raw coal. the amount is more preferably not name.
The nitrogen content of the second heavy oil is not particularly limited, but is preferably 0.2% by mass or less, more preferably 0.15% by mass or less, and further preferably 0.1% by mass or less. .

The raw material oil composition of the present invention is preferably obtained by mixing the first heavy oil and the second heavy oil described above. Moreover, the raw material oil composition of the present invention may further contain a vacuum distillation residue oil in addition to the first heavy oil and the second heavy oil.
The above-mentioned vacuum distillation residue oil has an initial boiling point of 300 ° C. or higher obtained as a residual oil when petroleum is distilled under reduced pressure, an asphaltene content of 12 mass% or less, a saturation content of 50 mass% or more, and a sulfur content of 0.3 mass%. The following heavy oils are preferred. Examples of the petroleums include crude oil, vacuum distillation residue obtained by distillation of crude oil, and mixed oils thereof. The treatment conditions when the above petroleums are distilled under reduced pressure are not particularly limited as long as the boiling point, asphaltene content, saturated content and sulfur content of the obtained vacuum distillation residue oil satisfy the above conditions, but the pressure is preferably 30 kPa or less, The temperature is preferably 400 ° C. or higher.

As a mixing ratio of the first heavy oil and the second heavy oil, when the activated carbon used for the electrode material for the electric double layer capacitor is manufactured, the content of the first heavy oil in the obtained raw material oil composition The ratio is preferably 5% by mass or more, more preferably 10% by mass, further preferably 15% by mass or more, preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less. It mix | blends so that it may become.
In the case of a combination of the first heavy oil, the second heavy oil, and the vacuum distillation residue oil, the content of the vacuum distillation residue oil is preferably 10% by mass or more, more preferably 20% by mass or more. More preferably, it is 30% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and still more preferably 50% by mass or less. At this time, the 1st heavy oil and the 2nd heavy oil are blended so that it may become 10 mass% or more, respectively.

Next, the raw material oil composition of the present invention is subjected to coking (carbonization) treatment.
Examples of the method for coking the raw material oil composition include a delayed coking method, a visbreaking method, a flexi coking method, a yurika process, and H-Oil. Among these, the delayed coking method is particularly preferable.
In the delayed coking method, the raw material oil composition is placed in a delayed coker and heat treated under pressure. The pressure of the delayed coker is preferably 300 to 800 kPa. The temperature is preferably 400 to 600 ° C, more preferably 450 to 550 ° C, and the time is preferably 24 to 72 hours, more preferably 36 to 60 hours.
By the coking process, carbide (raw coke) that becomes raw coal is obtained.

When the raw coal of the present invention is graphitized at a temperature of 2800 ° C. in an inert gas atmosphere, the ratio of the crystallite size and the lattice constant of the graphitized material is 360 or less, more preferably 350 or less on the 002 plane. , 110 has a structure of 1500 or less, more preferably 1300 or less.
The sulfur content of the raw coal of the present invention is usually 0.3% by mass or less, and the bulk specific gravity is usually 0.55 or more.
The raw coal of the present invention preferably has a true specific gravity of not less than 2.23, more preferably not less than 2.24 when graphitized at 2800 ° C. in an inert gas atmosphere. . If the true specific gravity is less than 2.23, the crystallites are randomly arranged, and the edge surfaces are closed by the crystallite surfaces.

In the present invention, when the first heavy oil alone or the mixed oil of the first heavy oil and the second heavy oil is heat-treated at 500 ° C., it is 10 μm or less present in the raw coal. The proportion of the mosaic structure is as small as 2% or less, preferably 1% or less. Here, a small proportion of a mosaic structure of 10 μm or less in the raw coal means that the growth state of liquid crystal called mesophase is good. The mesophase is an intermediate product produced by thermal decomposition and polycondensation accompanying heat treatment of the feedstock oil, and a series of aromatic rings developed along the same plane.
The method for measuring the mosaic structure in the raw coal is as described in “Basics of Carbonization Engineering”, Yuzo Sanada and Sugirou Otani (Ohm), page 147.

  Conventionally, when a raw material oil contains a large amount of a saturated component, particularly an aliphatic component, a crosslinking reaction occurs in addition to the polymerization and polycondensation of aromatic components during coking, so that a three-dimensional crystal grows and the mesophase is sufficient. It is considered that the structure does not grow and the crystallinity is inferior, and as a result, the coefficient of thermal expansion of needle coke is considered to increase, and the amount of residual alkali metal in the activated carbon is considered to increase. In view of this point, even if the saturation content of the first heavy oil is 50% by mass or more, a mosaic structure of 10 μm or less does not exist at all, or even if present, coking coal having 2% or less is obtained. That is a surprising result.

The raw coal obtained by the coking process can be converted into activated carbon by an alkali activation treatment. Moreover, in carrying out the alkali activation treatment, it is also preferably employed that the raw coal is heat treated at 550 to 900 ° C., preferably 600 to 850 ° C. under an inert atmosphere and normal pressure, and then subjected to the alkali activation treatment.
In the present invention, the activated carbon thus obtained is used as an electrode material for an electric double layer capacitor.

  As a method for activating the raw coal or the raw material for heat treatment of raw material carbon, an activation furnace is used to heat the raw material coal or the raw material for heat treatment of raw material coal at 500 to 1200 ° C. together with a metal hydroxide in an atmosphere of nitrogen gas or inert gas. A method can be mentioned. Specific examples of the metal hydroxide include alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and lithium hydroxide, and alkaline earth metal hydroxides such as magnesium hydroxide and barium hydroxide. be able to. Moreover, not only 1 type but 2 or more types can also be used in combination. Of these, potassium hydroxide is particularly preferable because it can efficiently form micropores.

The amount of the raw coal or raw material heat treated carbon and metal hydroxide can be 1 / 0.5 to 1/10 in the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide, Preferably it is 1/1 to 1/5.
By setting the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide to 1 / 0.5 or less, it is possible to sufficiently form micropores in the activated carbon and obtain activated carbon having a sufficient surface area. it can. Moreover, by making the mass ratio of raw coal or raw material heat treated carbon / metal hydroxide to 1/10 or more, the activation reaction can be efficiently performed without lowering the bulk density.
In addition, in the activation reaction, water or the like may coexist in addition to the raw coal or the raw material heat-treated with the raw coal and the metal hydroxide.

In the activation of the raw coal or the raw material for heat treatment of raw coal, the activation temperature may be, for example, in the range of 500 to 1200 ° C, preferably 600 to 1000 ° C, more preferably 600 to 800 ° C. Can do. When the activation temperature is in the above range, activated carbon having sufficient fine pores can be obtained efficiently. The activation treatment time can be appropriately selected in relation to conditions such as temperature, and can include 3 to 6 hours, for example.
Examples of the inert gas at the time of activation include inert gas and nitrogen gas. For example, it is preferable to supply such that the oxygen concentration in the activation atmosphere can be maintained at 100 ppm by volume or less.

The cleaning of the activated material is a cleaning in which the activated material is washed with a cleaning liquid to perform solid-liquid separation. The activated material is immersed in the cleaning liquid and mixed with the cleaning liquid by stirring and heating as necessary, and then the cleaning liquid is removed. The method of doing can be mentioned. As the cleaning liquid, water and an aqueous acid solution are preferably used. For example, cleaning with water, cleaning with an aqueous acid solution, and further cleaning with water can be used in appropriate combination. Preferred examples of the acid aqueous solution include hydrohalic acids such as hydrochloric acid, hydroiodic acid, and hydrobromic acid, and inorganic acids such as sulfuric acid and carbonic acid. Examples of the concentration of the acid aqueous solution include 0.01 to 3N. Cleaning with these cleaning liquids can be repeated a plurality of times as necessary.
After the final washing of the washing step using the washing liquid, solid-liquid separation is performed from the washing liquid, and heating, air drying, and the like are performed as appropriate to remove moisture and obtain dried activated carbon.

The activated carbon obtained by alkali activation of the raw coal or raw material heat treated carbon of the present invention has a feature that the residual alkali metal is reduced when washed by the same washing operation as compared with the conventional activated carbon. The reason why the residual alkali metal is reduced is that the raw coal and the raw material heat-treated with the coal according to the present invention have a crystal structure in which the metal hydroxide of the activator can easily enter and escape, and the obtained activated carbon This is considered to be due to the crystal structure that makes it easy for the cleaning liquid to enter and escape.
In addition to this, when the activated carbon according to the present invention is used for an electrode of an electric double layer capacitor, it is easy for electrolyte ions to enter and exit during charge and discharge, and the capacitance retention rate in the cycle characteristic test is improved. .
The electric double layer capacitor of the present invention uses activated carbon obtained from the raw coal of the present invention or a heat-treated product of raw coal as an electrode material.

The electrode of the electric double layer capacitor of the present invention is not particularly limited as long as it contains the above activated carbon, but may contain a binder, a conductive agent, etc., and is integrated with the current collector. It may be what you did.
As the binder, known ones can be used, and specifically, fluorinations such as polyolefins such as polyethylene and polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, and fluoroolefin / vinyl ether copolymer cross-linked polymers. Examples thereof include polymers, celluloses such as carboxymethyl cellulose, vinyl polymers such as polyvinyl pyrrolidone and polyvinyl alcohol, and polyacrylic acid. Specifically, the content of the binder in the electrode material may be 0.1 to 30% by mass.
Specific examples of the conductive agent include powders such as carbon black, acetylene black, and powdered graphite. As content in the electrode material of a electrically conductive agent, the range of 1-50 mass% is preferable, More preferably, it is 2-30 mass%.

In order to produce an electrode using these materials, for example, a method of adding the activated carbon, the binder, and a conductive agent to a solvent that dissolves the binder and applying the slurry as a slurry to a sheet-like current collector, Examples thereof include a method in which the activated carbon, the binder, and the conductive agent are kneaded without using a solvent and pressure-molded at room temperature or under heating.
As the current collector, known materials and shapes can be used, and specific examples include metals such as aluminum, titanium, tantalum, and nickel, and alloys such as stainless steel.
The electric double layer capacitor of the present invention can be produced as a unit cell in which a pair of electrodes are provided with a positive electrode and a negative electrode facing each other through a separator and immersed in an electrolyte solution. As the separator, unemployed cloth made of polypropylene fiber or glass fiber, cellulose paper, or the like can be used.

As the electrolytic solution, an aqueous electrolytic solution or a non-aqueous electrolytic solution can be used, but it is preferable to use a non-aqueous electrolytic solution. Examples of the non-aqueous electrolyte include those obtained by dissolving an electrolyte in an organic solvent. Specific examples of the solvent include propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, sulfolane, and 3-methylsulfolane. Such as sulfolane derivatives, 1,2-dimethoxyethane, etc., dimethoxyethane, acetonitrile, glutaronotolyl, valeronitrile, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, methyl formate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, etc. Can be used alone or in combination of two or more. Examples of the electrolyte of the electrolytic solution include inorganic ion salts such as alkali metal salts and alkaline earth metal salts, quaternary ammonium salts, cyclic quaternary ammonium salts, and quaternary phosphonium salts. _{C 2 H 5) 4 NBF 4} , (C 2 H 5) 3 (CH 3) NBF 4, (C 2 H 5) 4 PBF 4, (C 2 H 5) 3 (CH 3) PBF 4 and the like Can do. The electrolyte concentration in the electrolytic solution can be 0.1 to 5 mol / L, and preferably 0.5 to 5 mol / L.

As the shape of the electric double layer capacitor of the present invention, for example, a coin type and a pair of electrodes in which a pair of electrodes of a sheet shape or a disk shape having a thickness of 50 to 500 μm are housed in a metal case via a separator. Examples thereof include a wound type wound through a separator, and a laminated type in which a pair of electrodes provided via a separator are provided in multiple layers.
In the electric double layer capacitor of the present invention, since the activated carbon is used as an electrode material, cycle characteristics are improved, and excellent durability and excellent capacity retention are exhibited.

  In the present invention, “sulfur content” means a value measured in accordance with JIS K2541 in the case of oil, and a value measured in accordance with JIS M 8813 in the case of coke. The “nitrogen content” means a value measured according to JIS K 2609 in the case of oil, and a value measured according to JIS M 8813 in the case of coke. Further, “saturated content” and “asphaltene content” mean values measured using a thin layer chromatograph.

Coking coal of the present invention is used in the prime suitable as a activated carbon production for an electric double layer capacitor electrode.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example and a comparative example, this invention is not limited to a following example.

<Example 1>
(1) Preparation of raw material oil composition Hydrodesulfurization of middle-eastern atmospheric distillation residue having a sulfur content of 2.5% by mass in the presence of a Ni-Mo catalyst so that the hydrocracking rate is 25% or less. Thus, desulfurized heavy oil (hereinafter referred to as “hydrodesulfurized oil A”) was obtained. The hydrodesulfurization conditions were a total pressure of 22 MPa, a hydrogen partial pressure of 20 MPa, a temperature of 380 ° C., a hydrogen / oil ratio of 590 NL / L, and a liquid space velocity (LHSV) of 0.17 h ⁻¹ .
Also, using a vacuum distillation residual oil and desulfurized vacuum gas oil as raw material, a catalyst in which platinum (Pt) is supported on silica / alumina, a reaction temperature of 520 ° C., a total pressure of 0.2 MPa, a catalyst / oil ratio of 7, contact A fluid catalytic cracking residual oil (hereinafter referred to as “fluid catalytic cracking residual oil A”) was obtained at a time of 3 seconds.
Subsequently, the hydrodesulfurized oil A and the fluid catalytic cracking residual oil A were mixed at a mass ratio of 5: 5 to obtain a raw material oil composition A.

(2) Preparation of raw coal Next, the raw oil composition A was subjected to coking treatment at 500 ° C. under nitrogen and 400 kPa for 40 hours to obtain coke (raw coal A). This raw coal A was heat-treated at 2800 ° C. under nitrogen to obtain a graphitized product. Table 1 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.

(3) Activation of raw coal Coal 1 part by mass of raw coal A and 2.5 parts by weight of potassium hydroxide (KOH) are mixed, put into a nickel reaction vessel, heated at 700 ° C. for 1 hour under nitrogen, and activated. Went.
After the activation treatment, the reaction mixture inside the reaction vessel was cooled to 250 ° C., and carbon dioxide was flowed in place of nitrogen to deactivate the metal potassium. Thereafter, 20 kg of water was added to 2 kg of the reaction product, stirred at room temperature for 1 hour, and filtered under pressure. This operation was performed twice. Subsequently, 20 kg of 0.3N hydrochloric acid solution was added, stirred for 3 hours, and filtered under pressure. An additional 20 kg of water was added, and the mixture was stirred for 1 hour and filtered under pressure. This operation was also performed twice. The obtained solid was dried at 130 ° C. to obtain activated carbon for an electric double layer capacitor electrode. Table 2 shows the specific surface area, residual potassium amount and true specific gravity of the activated carbon.

(4) Production of electric double layer capacitor Activated carbon (0.8 g), Ketjen black (0.1 g) and polytetrafluoroethylene (0.1 g) obtained above were mixed in a mortar. This mixture was sandwiched between two 0.1 mm thick triacetate films and rolled by passing 20 times between nip rolls having a width of 160 mm, an upper and lower roll interval of 0.7 mm, and a pressure of 23.0 MPa. Two circles having a diameter of 16 mm were punched out from the rolled sheet to obtain carbon electrodes. The carbon electrode was dried in a vacuum dryer for 2 hours.
A cellulose separator having a thickness of 50 μm is sandwiched between two electrodes impregnated with an electrolytic solution (one mole of (C ₂ H ₅ ) ₃ (CH ₃ ) NBF ₄ dissolved in 1 liter of propylene carbonate) It was enclosed in a SUS316 coin cell having a diameter of 20 mm. In this case, a current collector carbon coating applied to the surface of a 20 μm thick aluminum foil was used as a current collector, and the paint side was sandwiched between the carbon electrode and the cell so as to face the carbon electrode.
Table 2 shows the capacitance and cycle characteristics (capacitance retention rate after 1000 charge / discharge cycles) of the electric double layer capacitor cell thus fabricated.

<Example 2>
An atmospheric distillation residue having a sulfur content of 3.0% by mass was distilled under reduced pressure at a heating furnace outlet temperature of 360 ° C. and a pressure of 1.3 kPa, an initial boiling point of 410 ° C., an asphaltene content of 8% by mass, and a saturation content of 50%. % Distillation residue oil A having a sulfur content of 0.1% by mass and a nitrogen content of 0.3% by mass was obtained.
Subsequently, the composition of the hydrodesulfurized oil A and the fluid catalytic cracking residual oil A of Example 1 was mixed so that the above-mentioned reduced-pressure distillation residue oil A was 30% by mass to obtain a raw material oil composition B.
Next, the raw material oil composition B was subjected to coking treatment at 500 ° C. for 40 hours under nitrogen and 400 kPa to obtain coke (raw coal B). This raw coal B was heat-treated at 2800 ° C. under nitrogen to obtain a graphitized product. Table 1 shows the X-ray diffraction measurement results (Gakushin Method 117 Committee) of this graphitized material.
An activation reaction and a capacitor were produced in the same manner as in Example 1 except that the raw coal B was used instead of the raw coal A. Table 2 shows the specific surface area of the activated carbon, the amount of residual potassium and the true specific gravity, and the capacitance and cycle characteristics of the capacitor cell (capacitance retention rate after 1000 charge / discharge cycles).

<Comparative Example 1>
The fluid catalytic cracking residual oil A used in Example 1 was subjected to coking treatment under nitrogen and 400 kPa at 500 ° C. for 40 hours to obtain coke. The coke was then heat treated at 2800 ° C. under nitrogen. Table 1 shows the X-ray diffraction measurement results (Gakushin 117 committee) of this heat-treated product. Further, the specific surface area, the residual potassium amount and the true specific gravity of the activated carbon obtained by alkali activation of the coke under the conditions of Example 1, and the capacitance and cycle characteristics of the capacitor cell (static capacity after 1000 charge / discharge cycles) Table 2 shows the retention rate of electric capacity.

<Comparative example 2>
The vacuum distillation residue oil A used in Example 2 was subjected to coking treatment under nitrogen, 400 kPa, and 500 ° C. for 40 hours to obtain coke. The coke was then heat treated at 2800 ° C. under nitrogen. Table 1 shows the X-ray diffraction measurement results (Gakushin 117 committee) of this heat-treated product. Further, the specific surface area, the residual potassium amount and the true specific gravity of the activated carbon obtained by alkali activation of the coke under the conditions of Example 1, and the capacitance and cycle characteristics of the capacitor cell (static capacity after 1000 charge / discharge cycles) Table 2 shows the retention rate of electric capacity.

  From Table 1 and Table 2, when the ratio of the crystallite size and the lattice constant on the 002 and 110 planes of the 2800 ° C. heat-treated product is 360 or less on the 002 plane and 1500 or less on the 110 plane, it is obtained by activation with KOH. The amount of potassium remaining in the obtained activated carbon is small, and the cycle characteristics of the electric double layer capacitor obtained by using such activated carbon, that is, the retention rate of the capacitance after repeating 1000 times of charge and discharge It is clear that the capacitor characteristics are excellent.

<Example 3>
(1) Preparation of raw material oil composition First, hydrodesulfurization of atmospheric distillation residue having a sulfur content of 3.5% by mass in the presence of a Ni-Mo catalyst so that the hydrocracking rate is 30% or less. A desulfurized heavy oil (hereinafter referred to as “hydrodesulfurized oil B”) was obtained. The hydrodesulfurization conditions were a total pressure of 18.5 MPa, a hydrogen partial pressure of 16.5 MPa, a temperature of 370 ° C., a hydrogen / oil ratio of 590 NL / L, and a liquid space velocity (LHSV) of 0.17 h ⁻¹ . The obtained hydrodesulfurized oil B has an initial boiling point of 260 ° C., a sulfur content of 0.3% by mass, a nitrogen content of 0.1% by mass, an asphaltene content of 2% by mass, and a saturated content of 70% by mass. there were.
This hydrodesulfurized oil B was put in a test tube and heat-treated at normal pressure and 500 ° C. for 3 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, a mosaic structure of 10 μm or less was not observed.
Further, desulfurized vacuum gas oil (sulfur content: 500 mass ppm, density: 0.88 g / cm ^{3 at} 15 ° C.) is subjected to fluid catalytic cracking to obtain fluid catalytic cracking residual oil (hereinafter referred to as “fluid catalytic cracking residual oil B”). It was. The initial boiling point of the obtained fluid catalytic cracking residual oil B is 210 ° C., the sulfur content is 0.1% by mass, the nitrogen content is 0.1% by mass, the asphaltene content is 0% by mass, and the saturation content is 30% by mass. Met.
This fluid catalytic cracking residual oil B was put in a test tube and heat-treated at normal pressure and 500 ° C. for 3 hours to be coke. When the produced coke was embedded in a commercially available resin and observed with a polarizing microscope, the presence of a mosaic structure of 10 μm or less was not recognized.

(2) Preparation of raw coal Next, hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 2: 8 to obtain raw oil composition C. This raw material oil composition C was subjected to heat treatment at 400 ° C. for 40 hours at 400 ° C. to be coke to obtain coke (raw coal C). When this raw carbon C was embedded in a commercially available resin and observed with a polarizing microscope, a mosaic structure of 10 μm or less was not recognized.

(3) Activation of raw coal Coal 1 part by mass of raw coal C and 2.5 parts by mass of potassium hydroxide (KOH) are mixed, put into a nickel reaction vessel, heated at 750 ° C. for 1 hour under nitrogen, and activated. Processed.
After the activation treatment, the reaction mixture inside the reaction vessel was cooled to 300 ° C., and carbon dioxide was passed instead of nitrogen to deactivate the metal potassium. Thereafter, 20 kg of water was added to 2 kg of the reaction product, stirred at room temperature for 1 hour, and filtered under pressure. This operation was performed twice. Subsequently, 20 kg of 0.3N hydrochloric acid was added, stirred for 3 hours, and filtered under pressure. An additional 20 kg of water was added, and the mixture was stirred for 1 hour and filtered under pressure. This operation was also performed twice. The obtained solid was dried at 130 ° C. to obtain activated carbon for an electric double layer capacitor. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon.

(4) Production of electric double layer capacitor An electric double layer capacitor was produced in the same manner as in Example 1 except that the activated carbon obtained above was used. Table 3 shows the capacitance and cycle characteristics (capacitance retention rate after 1000 charge / discharge cycles) of the electric double layer capacitor cell thus fabricated.

<Example 4>
The hydrodesulfurized oil B and fluid catalytic cracking residual oil B were mixed at a mass ratio of 8: 2 to obtain a raw material oil composition D. This raw material oil composition D was subjected to heat treatment at 400 ° C. for 40 hours at 500 ° C. to be coke to obtain coke (raw coal D). Except that 1 part by mass of raw coal D and 2.5 parts by mass of potassium hydroxide (KOH) were mixed, put in a nickel reaction vessel, heated at 750 ° C. for 1 hour under nitrogen, and subjected to activation treatment, The same operation as in Example 3 was performed to obtain activated carbon for an electric double layer capacitor. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon. Moreover, the electric double layer capacitor was produced by the same operation as Example 1 using the said activated carbon. Table 3 shows the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of capacitance after repeating charge and discharge 1000 times).

<Comparative Example 3>
Only the fluid catalytic cracking residual oil B obtained in Example 3 was heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke, and then subjected to alkali activation treatment in the same manner as in Example 3 to obtain An electric double layer capacitor was fabricated using activated carbon. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon, and the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of the capacitance after repeating charge and discharge 1000 times).

<Comparative example 4>
An atmospheric distillation residue (density 0.92 g / cm ³ , sulfur content 0.35 mass%) was distilled under reduced pressure under conditions of a heating furnace outlet temperature of 350 ° C. and a pressure of 1.3 kPa to obtain an initial boiling point of 410 ° C. and asphaltene. A vacuum distillation residue oil (hereinafter referred to as “vacuum distillation residue oil B”) having a content of 9% by mass, a saturation content of 61% by mass and a sulfur content of 0.1% by mass was obtained. The reduced-pressure distillation residue oil B is heat-treated at 400 ° C. for 40 hours at 500 ° C. to be coke, and then subjected to an alkali activation treatment in the same manner as in Example 3, and the obtained activated carbon is used for an electric double layer capacitor. Was made. Table 3 shows the specific surface area and the amount of residual potassium of the activated carbon, and the capacitance and cycle characteristics of the electric double layer capacitor cell (retention rate of the capacitance after repeating charge and discharge 1000 times).

  As is apparent from Table 3, the amount of potassium remaining in the obtained activated carbon is greatly reduced by using the raw material oil composition of the present invention obtained by mixing hydrodesulfurized oil and fluid catalytic cracking residual oil. As a result, the electrostatic capacity retention rate of the electric double layer capacitor using the same can be improved.

That is, the present invention has an initial boiling point obtained by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more, a saturated content of 60% by mass or more, a sulfur content of 0.5% by mass or less, and A first heavy oil having an asphaltene content of 5% by mass or less, a second heavy oil having an initial boiling point of 150 ° C. or higher and a sulfur content of 0.5% by mass or less obtained by fluid catalytic cracking of hydrocarbon oil Crystals of graphitized material obtained by coking a raw oil composition containing heavy oil at 300 to 800 kPa at 400 to 600 ° C. and graphitized at a temperature of 2800 ° C. in an inert gas atmosphere The present invention relates to a raw carbon for activated carbon for an electric double layer capacitor, characterized in that the ratio of the size of the element to the lattice constant is 350 or less on the 002 plane and 1500 or less on the 110 plane.

Further, the present invention provides a reaction temperature of 300 to 500 ° C., a hydrogen / oil ratio of 400 to 3000 NL / L, a total pressure of 16 MPa or more, a hydrogen partial pressure of 7 to 20 MPa, in the presence of a Ni—Mo catalyst and / or a Co—Mo catalyst. It is characterized by hydrodesulfurizing a heavy oil having a sulfur content of 2% by mass or more under a condition of a liquid space velocity (LHSV) of 0.1 to 3h ⁻¹ so that a hydrocracking rate is 30% or less. The present invention relates to the raw carbon for activated carbon for the electric double layer capacitor described above .
Further, the present invention provides a heavy oil having a sulfur content of 2% by mass or more, such as crude oil, atmospheric distillation residue obtained by distillation of crude oil, vacuum distillation residue, visbreaking oil, tar sand oil, shale oil, or It is the heavy oil chosen from these mixed oils, It is related with the above-mentioned raw material carbon for activated carbon for electric double layer capacitors characterized by the above-mentioned.
Further, the present invention provides a reaction temperature of 480 to 550 ° C., a total pressure of 1 to 3 kg / cm ² G (98 to 294 kPa gauge pressure) in the presence of a silica / alumina catalyst, a zeolite catalyst, or a catalyst in which platinum is supported on these catalysts. ), The above-mentioned raw carbon for activated carbon for an electric double layer capacitor, characterized in that hydrocarbon oil is fluidly cracked under conditions of a catalyst / oil ratio of 1 to 20 wt / wt and a contact time of 1 to 10 seconds.
In the present invention, the hydrocarbon oil is an atmospheric distillation residual oil, a vacuum distillation residual oil, a shale oil, a tar sand bitumen, an orinocotal, a coal liquefied oil, a heavy oil obtained by hydrorefining these, and a straight-run gas oil. The above-mentioned raw carbon for activated carbon for electric double layer capacitors, characterized in that it is vacuum gas oil, desulfurized gas oil, or desulfurized vacuum gas oil.

The present invention also relates to the raw carbon for activated carbon for an electric double layer capacitor as described above, wherein the content ratio of the first heavy oil in the raw material oil composition is 5% by mass or more and 95% by mass or less .
In the present invention, the raw oil composition contains the first heavy oil, the second heavy oil, and the vacuum distillation residue oil, and the content of the vacuum distillation residue oil is 10 to 70. The content of the first heavy oil and the second heavy oil is 10% by mass or more, and the above-mentioned raw carbon for activated carbon for an electric double layer capacitor is provided.
The present invention also relates to the raw carbon for activated carbon for an electric double layer capacitor described above, wherein the sulfur content is 0.3% by mass or less and the bulk specific gravity is 0.55 or more.

Hereinafter, the present invention will be described in detail.
In the raw coal of the present invention, the ratio of the crystallite size and the lattice constant when graphitized at 2800 ° C. in an inert gas atmosphere is 350 or less on the 002 plane and 1500 or less on the 110 plane. Gives structure. When the ratio of the crystallite size to the lattice constant on the 002 plane exceeds 350 , or the ratio of the crystallite size to the lattice constant on the 110 plane exceeds 1500, the ratio of the edge plane to the crystallites of the raw coal For this reason, it is considered that the amount of potassium remaining in the activated carbon increases because the cleaning liquid cannot enter the crystallites through the edge surface and the cleaning effect is reduced by the cleaning after the activation treatment.
Here, the interlayer distance d ₀₀₂ (lattice constant) of the microcrystalline carbon and the crystallite size Lc ₀₀₂ of the microcrystalline carbon were determined by the Japan Society for the Promotion of Science 117th Committee, “Lattice constant and crystallite of artificial graphite” In accordance with the “size measurement method”, the X-ray diffraction method is used as follows.

Coking coal of the present invention, an inert gas atmosphere, the ratio of the size and the lattice constant of crystallite graphite product when graphitized at a temperature of 2800 ° C. is, is 3 50 or less in a 002 plane, 1500 110 plane Hereinafter, it has a structure more preferably 1300 or less.
The sulfur content of the raw coal of the present invention is usually 0.3% by mass or less, and the bulk specific gravity is usually 0.55 or more.
The raw coal of the present invention preferably has a true specific gravity of not less than 2.23, more preferably not less than 2.24 when graphitized at 2800 ° C. in an inert gas atmosphere. . If the true specific gravity is less than 2.23, the crystallites are randomly arranged, and the edge surfaces are closed by the crystallite surfaces.

From Table 1 and Table 2, when the ratio of the crystallite size to the lattice constant on the 002 and 110 planes of the 2800 ° C. heat treatment is 350 or less on the 002 plane and 1500 or less on the 110 plane, it is obtained by activation with KOH. The amount of potassium remaining in the obtained activated carbon is small, and the cycle characteristics of the electric double layer capacitor obtained by using such activated carbon, that is, the retention rate of the capacitance after repeating 1000 times of charge and discharge It is clear that the capacitor characteristics are excellent.

Claims (12)

It has a structure in which the ratio of the crystallite size and the lattice constant of graphitized material when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 360 or less on the 002 plane and 1500 or less on the 110 plane. Coking coal to be used. 2. Coking coal according to claim 1, wherein the true specific gravity of the graphitized product when graphitized at a temperature of 2800 ° C. in an inert gas atmosphere is 2.23 or more. 2. Coking coal according to claim 1, wherein the sulfur content is 0.3 mass% or less and the bulk specific gravity is 0.55 or more. A first heavy oil having an initial boiling point of 200 ° C. or higher obtained by hydrodesulfurization of a heavy oil having a sulfur content of 2% by mass or higher under conditions of a total pressure of 16 MPa or higher so that the hydrocracking rate is 30% or lower. An oil and a second heavy oil having an initial boiling point of 150 ° C. or higher and a sulfur content of 0.5% by mass or less obtained by fluid catalytic cracking of hydrocarbon oil are contained. A raw material oil composition for producing the raw coal according to any one of the above. 5. The feed oil according to claim 4, wherein the first heavy oil is a heavy oil having a saturation content of 60% by mass or more, a sulfur content of 0.5% by mass or less, and an asphaltene content of 5% by mass or less. Composition. The hydrocarbon oil is atmospheric distillation residue, vacuum distillation residue, shale oil, tar sand bitumen, orinocotar, coal liquefied oil, heavy oil obtained by hydrorefining these, straight-run gas oil, vacuum gas oil, desulfurized gas oil The feed oil composition according to claim 4, which is a desulfurized vacuum gas oil. The feedstock composition according to any one of claims 4 to 6, wherein the feedstock composition gives a raw coal having a mosaic structure ratio of 10 µm or less of 2% or less when heat-treated at 500 ° C. The raw material oil composition according to any one of claims 4 to 7, wherein the raw material oil composition is subjected to coking treatment at 300 to 800 kPa and 400 to 600 ° C. Activated carbon obtained by activating the raw material coal according to any one of claims 1 to 3 or a raw material coal heat-treated product obtained by heat-treating the raw coal at 550 to 900 ° C under normal pressure with an alkali metal hydroxide. An electric double layer capacitor using the activated carbon according to claim 9 as an electrode material. Needle coke obtained by calcining the raw coal according to any one of claims 1 to 3 at 800 to 1600 ° C. The needle coke according to claim 11, wherein the sulfur content is 0.5 mass% or less, the nitrogen content is 0.1 mass% or less, and the bulk specific gravity is 0.82 or more.