JP2014173024A - Method of producing high-softening-point pitch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To utilize efficiently light, or low-boiling-point, ingredients in production of high-softening-point pitch, with the light ingredients so far discarded or only recycled as a fuel.SOLUTION: A method of producing high-softening-point pitch uses a raw material containing a heavy hydrocarbon oil and includes an oxidation step and a heat treatment step. In the heat treatment step, volatile ingredients (A) are recovered, and at least a part of the ingredients (A) is used as a part of the raw material.

Description

  The present invention relates to a method for producing a high softening point pitch.

The high softening point pitch has been conventionally used as a raw material for activated carbon, carbon fibers, battery negative electrode materials and the like.
As a method for producing a high softening point pitch, a method of using a heavy hydrocarbon oil or the like as a raw material and obtaining a high softening point pitch through an oxidation step and a heat treatment step is generally used.

  For example, as a method of producing a high softening point pitch, by heat treatment at 300 to 400 ° C. while blowing a specific amount of gas containing oxygen or ozone into heavy oil or pitch from which primary quinoline insoluble components have been removed, A method for producing a pitch having a softening point of 200 ° C. or higher and an isotropic quinoline insoluble component content of 5 to 50% is known (for example, see Patent Document 1).

However, Patent Document 1 does not propose any reuse of light (low boiling point) components distilled off during heat treatment.
In the conventional method of producing a high softening point pitch, the light (low boiling point) component is distilled off in the process of obtaining the high softening point pitch, and the distilled light (low boiling point) component is discarded or reused as fuel. It had been.

JP-A-7-194966

  An object of the present invention is to more efficiently utilize a light (low boiling point) component, which has been conventionally only discarded or reused as fuel, in the production of a high softening point pitch.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have used heavy hydrocarbons by using components that volatilize in the heat treatment process as part of the raw material for the high softening point pitch production method. The present inventors have found that a high softening point pitch can be efficiently produced from oil and completed the present invention.

  That is, the method for producing a high softening point pitch according to the present invention is a method for producing a high softening point pitch through a raw material containing heavy hydrocarbon oil through an oxidation step and a heat treatment step, and volatilizes in the heat treatment step. The component (A) is recovered, and at least a part of the component (A) is used as a part of the raw material.

Of the component (A), a substance having a normal boiling point exceeding 270 ° C. [component (B)] is preferably used as a part of the raw material.
It is preferable that the heat treatment step is a step of distilling off the volatile component (A) under reduced pressure after carrying out thermal heaviness.

The heavy hydrocarbon oil is preferably at least one selected from petroleum tar, coal tar, and ethylene bottom oil.
The raw material is preferably a raw material containing 3 to 40 parts by mass of the component (A) per 100 parts by mass in total of the heavy hydrocarbon oil and the component (A).

  The raw material is preferably a raw material containing 0.6 to 38 parts by mass of the component (B) per 100 parts by mass in total of the heavy hydrocarbon oil and the component (B).

  In the method for producing a high softening point pitch of the present invention, the yield based on heavy hydrocarbon oil is improved by using a component that volatilizes in the heat treatment step as part of the raw material.

Next, the present invention will be specifically described.
The method for producing a high softening point pitch of the present invention is a method for producing a high softening point pitch through an oxidation step and a heat treatment step using a raw material containing a heavy hydrocarbon oil. A) is recovered, and at least a part of the component (A) is used as a part of the raw material.

〔material〕
The method for producing a high softening point pitch of the present invention uses heavy hydrocarbon oil as a raw material. As the heavy hydrocarbon oil, petroleum tar, coal tar, ethylene bottom oil (EHE) and the like can be used. Petroleum tar is mainly generated during oil refining, and coal tar is mainly generated during coal dry distillation. The ethylene bottom oil is a heavy fraction having the highest boiling point among naphtha cracked fractions produced as a by-product when ethylene is produced by cracking naphtha and the like.

  In the method for producing a high softening point pitch of the present invention, a high softening point pitch is obtained through an oxidation process and a heat treatment process, which will be described later. In the present invention, in the heat treatment process, the component (A) that volatilizes is recovered and It is used as a part.

That is, heavy hydrocarbon oil and component (A) are mentioned as a raw material in the manufacturing method of the high softening point pitch of this invention.
In addition, in the manufacturing method of the high softening point pitch of this invention, it is preferable to manufacture a high softening point pitch continuously. In this case, only the heavy hydrocarbon oil is used as a raw material for producing the high softening point pitch at first, and the component (A) is recovered in the process of producing the high softening point pitch. Then, it is used as a part of a raw material when manufacturing a high softening point pitch.

  The component (A) is a component that volatilizes in the heat treatment step described later, and specifically is a mixture containing naphthalene, α, β-methylnaphthalene, biphenyl, acenaphthene, fluorene, phenanthrene, pyrene and the like.

Further, as described later, in the present invention, among the components (A), it is preferable to use a substance [component (B)] having a normal boiling point exceeding 270 ° C. as a part of the raw material.
In the component (A), examples of the substance having a normal boiling point exceeding 270 ° C. include fluorene, phenanthrene, and pyrene.

  The method for separating the component (B) from the component (A), that is, the substance having a standard boiling point exceeding 270 ° C. is not particularly limited, but the standard boiling point is usually obtained from the component (A) by distillation such as vacuum distillation. Can be obtained by removing a light component having a standard boiling point of more than 270 ° C. as a balance.

  The distillation is usually performed under reduced pressure, preferably at a pressure of 0.001 to 0.09 MPa and a temperature of 30 to 265 ° C. When recovering the component (B) from the component (A) by vacuum distillation, the temperature at which the light component having a standard boiling point of 270 ° C. or less varies depending on the pressure. For example, under a reduced pressure of 0.003 MPa, When performing distillation under reduced pressure, the light component having a normal boiling point of 270 ° C. or less can be distilled off by distilling the component (A) until the vapor phase temperature at the top of the distillation column reaches 165 ° C., and the remainder As a result, the component (B) can be obtained.

  As described above, when obtaining the component (B) from the component (A), the temperature at which the light component having a standard boiling point of 270 ° C. or less distills varies depending on the pressure at which distillation under reduced pressure is performed. Based on the vapor pressure curve in the single-component system, it is possible to determine the temperature at which the light component having a standard boiling point of 270 ° C. or less is distilled at each pressure.

In addition, in the component (A) obtained by the below-mentioned heat treatment process, 20-80 mass% of components (B) are normally contained in 100 mass% of this component (A).
It is preferable to use the component (B) as the component (A) used as a part of the raw material because the yield based on heavy hydrocarbon oil is particularly excellent.

  In addition, when using a component (A) as a part of raw material, this raw material normally contains 3-40 mass parts of components (A) per 100 mass parts of total of heavy hydrocarbon oil and a component (A). And preferably 5 to 35 parts by mass.

  In particular, when component (B) is used as component (A), the raw material usually contains component (B) in an amount of 0.6 to 38 parts by mass per 100 parts by mass of the heavy hydrocarbon oil and component (B). Contained, preferably 5 to 35 parts by mass.

[Oxidation process]
The manufacturing method of the high softening point pitch of this invention has an oxidation process. The oxidation step is usually performed by an air blowing reaction in which a gas containing an oxidizing gas such as oxygen, that is, air or the like is blown and a raw material containing heavy hydrocarbon oil is heated. The air blowing reaction is usually performed by blowing air.

  In the air blowing reaction, the oxidation reaction to the raw material containing heavy hydrocarbon oil by oxidizing gas such as oxygen and the distillation effect by air blowing occur simultaneously, so the reaction is complicated and the details are not clear, but air blowing By performing the treatment, it is possible to increase the softening point and increase the toluene insoluble content without generating an anisotropic structure.

  If the temperature for performing the air blowing reaction is too low, the viscosity of the raw material containing the heavy hydrocarbon oil is high, and a uniform reaction cannot be performed. If it is too high, the vapor pressure of the raw material containing heavy hydrocarbon oil will increase and the yield will decrease, and the reaction will run away due to abrupt reaction, or the raw material containing heavy hydrocarbon oil will become heavier. However, these cause a solidification reaction in the reaction system, which is not preferable.

The temperature for performing the air blowing reaction is preferably 150 to 350 ° C, more preferably 200 to 300 ° C.
Since the air blowing reaction is a gas-liquid reaction, in order to advance the reaction efficiently, it is preferable to promote the dissolution of air into the raw material containing the heavy hydrocarbon oil, and it is preferable to advance the reaction under pressure.

  The pressure is preferably higher, but it is preferably 0.2 to 2 MPaG (gauge pressure), more preferably 0.3 to 1 MPaG in consideration of the apparatus and safety.

  The quantity ratio between the raw material containing heavy hydrocarbon oil and the gas containing oxidizing gas is not particularly limited, but when the air blowing reaction is performed by blowing air, per 1 kg of the raw material containing heavy hydrocarbon oil Preferably, a range of 150 to 300 minutes at 0.5 to 10 NL / min, more preferably 150 to 300 minutes at 0.7 to 7 NL / min is used.

  In addition, the tar obtained by the oxidation process from the said raw material is also described as an oxidation tar, and when the oxidation process is performed by air blowing reaction, the obtained tar is also described as an air blowing tar.

[Heat treatment process]
The manufacturing method of the high softening point pitch of this invention has a heat treatment process. The heat treatment step is a step of obtaining a high softening point pitch by removing (recovering) the component (A) that is volatilized by heat treatment and heat treatment with respect to the oxidized tar such as air blowing tar usually obtained by the oxidation step. It is.

The heat treatment step is preferably a step of distilling off the volatilized component under reduced pressure after thermal heavyification.
Thermal heaviness is a phenomenon in which a molecular cross-linking reaction occurs due to heat and a higher boiling point component increases.

The thermal heavyening is usually performed at a temperature of 300 to 400 ° C, preferably 350 to 400 ° C, and the required time is usually 1 to 5 hours.
The reduced-pressure distillation is an operation performed to recover the component (A) (light component) that volatilizes after the thermal heavyification, and the pressure is 0.005 to 0.09 MPa and the temperature is 280 to 380. It is preferable to be performed under the condition of ° C.

  In addition, in the manufacturing method of the high softening point pitch of this invention, the component (A) which volatilizes is discharge | released also in the case of normal heat heaviness. It is preferable from the viewpoint of the yield that the components that volatilize during the thermal heavyification are also recovered.

The method for producing a high softening point pitch of the present invention is preferable because the component (A) is used as a part of the raw material, so that the yield of the high softening point pitch based on heavy hydrocarbon oil can be increased.
It is preferable that the manufacturing method of the high softening point pitch of this invention is performed when manufacturing a high softening point pitch continuously. That is, when producing a high softening point pitch for the first time, since it does not have the usual component (A), a high softening point pitch is produced using heavy hydrocarbon oil as a raw material and recovered during the production. By using the component (A) as a part of the raw material together with the heavy hydrocarbon oil, it becomes possible to continuously produce a high softening point pitch.

(High softening point pitch)
In the manufacturing method of the high softening point pitch of this invention, a high softening point pitch is obtained by performing the above-mentioned oxidation process and heat processing process using the raw material containing the said heavy hydrocarbon oil and a component (A).

  The high softening point pitch obtained by the production method of the present invention has a softening point of usually 150 ° C. or higher, preferably 150 ° C. to 350 ° C., more preferably 200 to 300 ° C., and a toluene insoluble content is usually 40 to 75 ° C. %, Preferably 45 to 75%, more preferably 50 to 75%.

  The high softening point pitch obtained by the production method of the present invention can be used as a raw material for activated carbon, carbon fibers, battery negative electrode materials and the like.

EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited by these.
[Example 1]
(Manufacture of high softening point pitch and recovery of light component (component (A)))
A stainless steel pressure vessel (reaction vessel) is charged with 10 kg of bottom oil (ethylene bottom oil) produced during the production of ethylene, and air is blown from the bottom of the reaction vessel at 10.1 NL / min, under a pressure of 0.4 MPaG, 150 to 250 By performing the air blowing reaction at 200 ° C. for 200 minutes, 9.55 kg of air blowing tar was obtained.

  After 3.0 kg of the obtained air blowing tar was heat-heavy at 385 ° C. for 2 hours, the light component was further distilled off under reduced pressure at 0.013 MPa, so that the softening point was 206 ° C. and the toluene insoluble content was 55.9%. 1.26 kg of air blowing pitch (high softening point pitch) was obtained.

The yield based on ethylene bottom oil was 40% by mass. In addition, 1.7 kg of a light component (component (A)) released out of the system by heat heaviness and distillation under reduced pressure was recovered.
A total of 3.4 kg of component (A) was obtained by carrying out thermal heaviness of the air blowing tar and vacuum distillation again.

(Manufacture of high softening point pitch using component (A))
A stainless steel pressure vessel is charged with 6.67 kg of bottom oil (ethylene bottom oil) produced during the production of ethylene and 3.33 kg of component (A), and air is blown from the bottom of the reaction vessel at 10.1 NL / min to a pressure of 0.4 MPaG. 9.38 kg of air blowing tar was obtained by carrying out an air blowing reaction for 200 minutes at 150 to 250 ° C. under pressure.

The resulting air blowing tar (3.0 kg) was heat-heavy at 385 ° C. for 2 hours, and the light component was further distilled off under reduced pressure at 0.013 MPa, so that the softening point was 214 ° C. and the toluene insoluble content was 59.8%. An air blowing pitch (high softening point pitch) of 1.02 kg was obtained.
The yield based on ethylene bottom oil was 48% by mass. By using component (A) as part of the raw material, the yield based on ethylene bottom oil was improved.

[Example 2]
(Manufacture of high softening point pitch and recovery of light component (component (A)))
A stainless steel pressure vessel (reaction vessel) is charged with 10 kg of bottom oil (ethylene bottom oil) produced during the production of ethylene, and air is blown from the bottom of the reaction vessel at 10.1 NL / min, under a pressure of 0.4 MPaG, 150 to 250 By performing the air blowing reaction at 200 ° C. for 200 minutes, 9.55 kg of air blowing tar was obtained.

  After 3.0 kg of the obtained air blowing tar was heat-heavy at 385 ° C. for 2 hours, the light component was further distilled off under reduced pressure at 0.013 MPa, so that the softening point was 206 ° C. and the toluene insoluble content was 55.9%. 1.26 kg of air blowing pitch (high softening point pitch) was obtained.

The yield based on ethylene bottom oil was 40% by mass. In addition, 1.7 kg of a light component (component (A)) released out of the system by heat heaviness and distillation under reduced pressure was recovered.
A total of 13.6 kg of component (A) was obtained by manufacturing the air blowing tar three times, heat-healing the air blowing tar, and performing vacuum distillation eight times.

(Recovery of component (B) from component (A))
Charge 4.0 kg of component (A) to a 5 L round bottom flask and heat in an Oldershaw type precision distillation column under a reduced pressure of 0.003 MPa, and the vapor phase temperature at the top of the distillation column becomes 165 ° C. from room temperature. And the light component was distilled off under reduced pressure to obtain 1.4 kg of a component (B) (a substance having a normal boiling point exceeding 270 ° C.) as the balance. By performing this operation three times, a total of 4.2 kg of component (B) was obtained.

(Manufacture of high softening point pitch using component (B))
A stainless steel pressure vessel is charged with 6.67 kg of bottom oil (ethylene bottom oil) produced during the production of ethylene and 3.33 kg of component (B), and air is blown from the bottom of the reaction vessel at 10.1 NL / min to a pressure of 0.4 MPaG. 9.62 kg of air blowing tar was obtained by performing an air blowing reaction at 150-250 ° C. for 220 minutes under pressure.

After 3.0 kg of the air blowing tar obtained was heat-heavy at 385 ° C. for 2 hours, the light component was further distilled off under reduced pressure at 0.013 MPa, so that the softening point was 203 ° C. and the toluene insoluble content was 55.7%. 1.12 kg of air blowing pitch (high softening point pitch) was obtained.
The yield based on ethylene bottom oil was 54% by mass. By using component (B) as part of the raw material, the yield based on ethylene bottom oil was improved.

[Comparative Example 1]
(Manufacture of high softening point pitch)
A stainless steel pressure vessel (reaction vessel) is charged with 10 kg of bottom oil (ethylene bottom oil) produced during the production of ethylene, and air is blown from the bottom of the reaction vessel at 10.1 NL / min, under a pressure of 0.4 MPaG, 150 to 250 By performing the air blowing reaction at 200 ° C. for 200 minutes, 9.55 kg of air blowing tar was obtained.

After 3.0 kg of the obtained air blowing tar was heat-heavy at 385 ° C. for 2 hours, the light component was further distilled off under reduced pressure at 0.013 MPa, so that the softening point was 206 ° C. and the toluene insoluble content was 55.9%. 1.26 kg of air blowing pitch (high softening point pitch) was obtained.
The yield based on ethylene bottom oil was 40% by mass.

Claims (6)

It is a method for producing a high softening point pitch through an oxidation process and a heat treatment process using a raw material containing heavy hydrocarbon oil,
In the heat treatment step, the volatile component (A) is recovered,
The manufacturing method of the high softening point pitch which uses at least one part of this component (A) for a part of said raw material.   The manufacturing method of the high softening point pitch of Claim 1 which uses the substance [component (B)] whose normal boiling point exceeds 270 degreeC among the said components (A) as a part of said raw material.   3. The method for producing a high softening point pitch according to claim 1, wherein the heat treatment step is a step of distilling off the volatile component (A) under reduced pressure after heat-heavyening. 4.   The method for producing a high softening point pitch according to any one of claims 1 to 3, wherein the heavy hydrocarbon oil is at least one selected from petroleum tar, coal tar, and ethylene bottom oil.   The raw material is a raw material containing 3 to 40 parts by mass of the component (A) per 100 parts by mass in total of the heavy hydrocarbon oil and the component (A). Manufacturing method of high softening point pitch.   The high-softening point pitch according to claim 2, wherein the raw material is a raw material containing 0.6 to 38 parts by mass of the component (B) per 100 parts by mass in total of the heavy hydrocarbon oil and the component (B). Production method.