JPS60245696A - Method for refining decanted oil - Google Patents

Abstract

PURPOSE:To remove submicroscopic catalyst particles efficiently, by subjecting decanted oil to a graviation, centrifugation or filter treatment in the former stage of refining and adding a small quantity of a liquid thereto in the latter stage to form an emulsion, and precipitating the catalyst particles. CONSTITUTION:In the refining of decanted oil formed as by-product in the catalytic thermal cracking of petroleum as raw oil in a fluidized bed cracker, the decanted oil is subjected to a graviation treatment and/or a centrifugation treatment and/or a filter treatment in the former stage and a small quantity of a liquid (e.g. ethylene glycol or glycerin) having a specific gravity (15 deg.C/4 deg.C) exceeding 1 and a solubility parameter of 14.5 or above is added thereto by stirring in the latter stage to form an emulsion and catalyst particles are precipitated, thus efficiently removing submicroscopic catalyst particles. The problem of the formation of voids due to submicroscopic catalyst particles in spinning catbon fiber starting from decanted oil as raw material can be eliminated by the above process, and a carbon fiber having a high strength can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid catalytic cracking apparatus:
Concerning a method of refining oil. More details (Well, decane produced as a by-product from a fluid catalytic cracker using petroleum as feedstock 1~
When refining oil, a small amount of liquid with a specific gravity of more than 1 at 15°C/4°C and a solubility parameter of 145 or more is processed in the latter stage after being processed by gravity or centrifugation) and/or filter. Add, mix and stir;
This is a method for refining Decashi I-oil, which is characterized by efficiently removing catalyst pieces of 117 microns by emulsifying and precipitating.

Conventionally, decanted oil has been purified by using a passage, gravity, or centrifugal force, and/or filters, but these methods are not effective in removing catalyst particles up to micron sized, for example, about 2μ or larger. However, it was extremely difficult to remove submicron catalyst pieces. For this reason, when the decant oil is used as a raw material oil and subjected to a thermal reforming reaction to form pitch and further to make carbon fiber, pores are generated due to the above-mentioned submicron catalyst pieces during spinning, and these are further added to the carbon fiber. This residual content causes a decrease in strength, making it difficult to obtain high-performance carbon fibers.

In other words, to explain carbon fiber in more detail, carbon fiber (graphitized Il fibers are also collectively included in carbon fiber) is lightweight, has high strength, high modulus of elasticity, heat resistance, chemical resistance, and It has the characteristic of electrical conductivity and is said to be one of the promising industrial materials, especially in terms of specific strength (strength per unit weight) and specific modulus (modulus of elasticity per unit weight). Because of their large size, they are used in the form of composite materials with synthetic resins, metals, or carbon, and are expected to be used in large quantities in the future for aerospace, automobiles, and mechanical materials.

Carbon fibers can be made of lignin-based, cellulose-based, polyacrylic nitrile-based,
It is classified into rayon-based, pitch-based, etc., but its properties vary greatly depending on the precursor organic substance. It is generally known that the properties of the final product of carbon materials are largely controlled by differences in the properties of the precursor organic substances, and the case of carbon [1 is also a typical example of this.

Pitch-based carbon fibers are characterized by the fact that the precursor pitch, which is the raw material, is cheaper than polyacrylonitrile. It is a general term for substances that are solid and turn into a viscous oil when heated, and does not refer to a specific substance, but exists in a variety of properties. Therefore, it can be said that the industrial value of developing a method for manufacturing raw material bidge for carbon cords with high strength and high elastic modulus by skillfully controlling the properties of the pitch can be said to be extremely large. Currently, methods for producing high-strength, high-modulus carbon fibers using pitches as raw materials include methods in which pitch fibers obtained from optically isotropic pitch are carbonized and/or graphitized under tension treatment, and mesophase. A method using a large amount of optically anisotropic pitch as a raw material has been proposed.

For example, Japanese Patent Laid-Open No. 57-88016 discloses a method for producing raw material pitch for carbon fiber production using as a starting material a tar-like substance produced by the catalytic cracking of petroleum or a tar-like substance produced by the thermal decomposition of naphtha. In this method, after the starting material is heat-treated, the mesophase is concentrated and separated and recovered by gravity sedimentation to obtain mesophase-containing pitch, and the mesophase-containing pitch is roughly heat-treated in the next step. Manufactures raw material pitch for carbon fiber manufacturing. This shows that pitch suitable for manufacturing carbon fibers cannot be produced by simple heat treatment of the two tar-like substances mentioned above. In general, mesophase refers to condensed polycyclic aromatic molecules produced by thermal decomposition and polycondensation reactions during the so-called initial carbonization process of heat-treating heavy oils, which are mainly arranged by van der Waals horns and exhibit a certain orientation. It refers to the intermediate phase (mesophase), which refers to the liquid crystal state and is the process in which heavy oil in the liquid phase changes to carbide in the solid phase. In the past, mesophase was defined as being equivalent to quinoline-soluble matter, but recent research has revealed that mesophase and quinoline-soluble matter are not equivalent. Furthermore, the part that exhibits optical anisotropy under a polarizing microscope can be said to be not equivalent to a mesophase because it changes greatly depending on the observation temperature and sample preparation method. Therefore, it is no exaggeration to say that there is currently no perfect method for measuring the amount of mesophase.

carbon! A pitch suitable for the production of I fibers, particularly high strength, high modulus carbon fibers, requires a very large number of properties. First, it is necessary that fibers with a diameter of 5 to 15 μm can be spun at high speed during the spinning process, and that there is little yarn breakage. Furthermore, it is necessary to be able to perform spinning at a temperature of 300 to 400° C. in order to prevent the sea from fusing after spinning and to perform the subsequent infusibility process well. Furthermore, it is necessary that the strength of the pitch fiber after spinning is high. In addition, in the carbonization and graphitization steps, it is necessary that the arrangement of the hexagonal network planes of carbon be well developed and the graphitization properties should be good. Generally, heavy oils contain hydrocarbons, sulfur compounds, nitrogen compounds, oxygen compounds,
In addition to the presence of many types of components such as and organometallic compounds,
These components have a wide molecular weight distribution and many have complex structures. Therefore, the thermal reactivity of each component differs greatly, and when such heavy oils are subjected to heat treatment, the product product also becomes a mixture of components with greatly different properties. Therefore, even when producing raw material pitch for carbon fiber production by heat treatment of heavy oil, it is assumed that some components will have properties suitable for raw material pitch if only a simple heat treatment operation is applied to the heavy oil. Also, large amounts of components with inappropriate properties are produced.

In the above-mentioned Japanese Patent Application Laid-Open No. 57-88016, no special measures were taken for the thermal reforming method, so the yield of a component having properties desirable as a raw material pitch was low.

In addition, methods such as low force sedimentation and centrifugal force sedimentation can be used to remove residual -C catalyst fragments and polymer substances from the reaction product after carrying out a thermal reforming reaction. Although this method has been used in the past, it has been problematic because its separation ability is insufficient and it is difficult to completely separate fine particles with a particle size of 01 to 1 μm.

In other words, in a liquid with a diameter of 0.2μ, a viscosity of 4 cp, and a specific gravity difference of 1.5, the sedimentation velocity is 0.0064 mm/Sec (0,
4 mm/m1n), and efficient continuous separation is slow. In addition, these fine particles, which are residual catalyst pieces, act as nuclei for gas generation during spinning, and in addition to forming pores in the fibers as mentioned above, they also form carbon particles after the infusibility process, carbonization, and graphitization process. These particles had a negative effect on the strength of the fiber braid, causing a decrease in strength.

In view of the above circumstances, the present inventors have conducted various studies on refining decant oil produced as a by-product from a fluid catalytic cracker using bundled petroleum as feedstock oil. After treatment, in the latter stage, a small amount of liquid with a specific gravity of 15°C/4°C exceeding 1 and a solubility parameter of 145 or higher is added, mixed, stirred, emulsified, and precipitated. This is a method for refining decant oil characterized by the efficient removal of debris, specifically at 15°C,
/4℃ specific gravity exceeds 1 and solubility parameter is 1
45 or more is characterized by being one or more liquids from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, and glycerin, and to further improve efficiency, it is preferable to combine the above-mentioned liquids with water. The present inventors have invented a method for refining decant oil, which is characterized by efficiently removing submicron catalyst pieces by emulsifying a mixture and allowing it to settle.

In this case, it is not preferable to omit the first stage treatment step and only perform the second stage separation by emulsification, since this will result in a large amount of remaining catalyst pieces.

Also, the reason why liquids with a specific gravity of 15℃/4℃ exceeding 1 are removed is because the specific gravity of decant oil is 096-102, which is higher than that of ordinary petroleum fractions, so the mixed and stirred liquids are separated by sedimentation. It's for a reason.

The reason why we use a liquid with a solubility parameter of 145 or more is that if the solubility parameter is less than this, the solubility parameter of decant oil will be close to 9, and when emulsified, the amount dissolved will be large and separation will be insufficient. This is to become. To further reduce this amount of dissolution and improve the adsorption of catalyst pieces at the interface, water (solubility parameter -
- Good to use in combination with 23.4). Note that the solubility parameters are as generally used in solvent 1 at 25°C.
The intermolecular bonding energy of d (the value obtained by subtracting the energy of the gas from the latent heat of vaporization: the square root of cal/mf).

Further, the solubility parameters of typical liquids used in the present invention are ethylene glycol-163, propylene glycol-14°8, diethylene glycol, and col-14,6.
, glycerin-21,1.

Next, the present invention will be explained in detail with reference to examples, but the present invention is not limited to the following examples unless the gist of the present invention is exceeded. ' [Example-11 Decanted oil containing 130 ppm of catalyst fragments produced as a by-product from a fluid catalytic cracker (specific gravity at 15°C/4°C - 99
), in the first stage it was filtered through a 3μ sintered stainless steel filter, and in the second stage a mixture of 90% ethylene glycol and 10% water (specific gravity at 15°C/4°C = 1.1
0, solubility parameter = 17.0) to the filtered, decanted oil at 1500 ml in a container.
The mixture was stirred at a speed of ppm for 15 minutes to form an emulsion, and left to stand at 70°C for sedimentation. 48 hours 1 change.”
The liquid was removed and filtered through a 01μ millibore filter to measure the amount of catalyst pieces remaining, which was found to be 0.5 ppm. Table 1 shows examples and comparative examples.

Table 1 [Example-2] Decane 1 oil (specific gravity at 15°C/4°C = -i, oo
) was purified using a centrifugal pH machine in the first stage, and then in the second stage a mixture of 40% ethylene glycol: 40% zo[]pyrene glycol; 20% water (15°C/4°C
After adding 10% of (specific gravity -106, solubility parameter = 17.1) to the filtered decant oil, it was stirred in a container at a speed of 150 rpm for 15 minutes to form an emulsion, and then heated at 700 C to precipitate. I left it still.

After 48 hours, the supernatant was taken and filtered through a 01μ millibore filter to measure the amount of catalyst fragments remaining, which was 0.6.
It was ppm. Table 2 shows the present example and comparative examples.

'Table 2 [Example-3] Decane l-oil (specific gravity at 15°C/4°C -i, oo
) to purify it, after processing it in a centrifuge in the first stage,
In the latter stage, a mixture of 80% glycerin and 20% water (15°C
/4℃ specific gravity -121, solubility parameter -216)
was added to filtered decane 1 in an amount of 10% based on the oil, then stirred in a container at a speed of 150 rpm for 15 minutes to form an emulsion, and left to stand at 80°C for sedimentation and mixing. After 24 hours, the supernatant was taken, filtered through a 0.1μ millibore filter, and the remaining catalyst pieces were measured.
It was 0.7 ppm. Table 3 shows the present example and comparative examples.

Table 3 [Example-4] Fluid catalytic cracking device J: By-product of catalytic cracking, catalyst pieces 180 p p
Decanted oil containing m (specific gravity at 15°C/4°C -
102), it was filtered through a 3μ sintered stainless steel filter in the first stage, and a mixture of 90% ethylene glycol and 10% water (15°C/4°C specific gravity -
1,10, solubility parameter -17,0, hereinafter Solvent A
) or ethylene glycol ((specific gravity at 15°C/4°C -112, solubility parameter -16.3, hereinafter Solvent B)
) was added at 5% to the filtered decant oil, stirred in a container at a speed of 1500 rpm for 15 minutes to form an emulsion, and further processed in a centrifugal machine to remove ten parts of the liquid (light liquid). The remaining amount of catalyst pieces was measured by filtration through a 01μ Mirabore filter. This example is shown in Table 4.9 Table 4 Patent Applicant: Mitsubishi Oil Corporation (1 other person)

Claims (1)

[Claims] 1. In refining the decant oil produced as a by-product from a fluid catalytic cracker, gravity and/or centrifugal force and b+, < is filtered in the first stage, and then 1 in the second stage.
A small amount of liquid with a specific gravity of 5℃/4℃ exceeding 1 and a solubility parameter of 145 or higher is added, mixed, stirred, emulsified, and separated by sedimentation to efficiently remove Zabumicron catalyst pieces. How to refine decant oil. The liquid with a specific gravity of more than 1 at 215°C/71°C and a solubility parameter of 145 or more must be one or more solvents from the group consisting of: ethylene glycol, propylene glycol, diethylene glycol, and glycerin. A method for refining decant oil according to claim 1, characterized in that: A liquid having a specific gravity of 315°C/4°C exceeding 1 and a solubility parameter of 14.5 or more is 1-dilene glycol,
The method for refining decant oil according to claim 1, wherein the method is a mixture of water and one or more liquids from the group consisting of propylene glycol, diethylene glycol, and glycerin.