JPH0386789A - Method for fractionating beta resin - Google Patents

Abstract

PURPOSE:To efficiently produce beta-resin useful as a raw material for a highly value-added carbon product using simple equipment by treating coal tar pitch with solvents under specific conditions. CONSTITUTION:Coal tar pitch 4 pref. having a softening point of 100 deg.C or lower and a mixed solvent 5 comprising the first arom. solvent (e.g. coker gas oil) and an aliph. solvent (e.g. kerosene) are introduced into the first fractionating zone 1, where they are mixed and kept standing to separate into two phases, a low-density liq. 7 and a high density liq. 8 mainly comprising quinoline-insols. (e.g. carbon, ash, and other inorg. matters), and both liqs. are separately taken out. After the solvent 9 of the low density liq. 7 is removed, the solvent-free low density liq. 10 and the second arom. solvent (e.g. toluene) are introduced in a wt. ratio of the second solvent to the coal tar pitch component of 0.5-5 into the second fractionating zone 2, where they are kept at a temp. in the range of from the critical temp. of the second arom. solvent to 370 deg.C under a pressure in the range of from the critical pressure of the second arom. solvent to 100kg/cm<2>G to separate into two phases, a low density liq. 13 mainly comprising toluene-sols. and a high density liq. 14 mainly comprising beta-resin, and both liqs. 13 and 14 are separately taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is directed to the use of quinoline-soluble components (hereinafter referred to as 91 min. ), which is insoluble in toluene and soluble in quinoline and is an important raw material for high value-added carbon products
The present invention relates to a method of fractionating pitch mainly consisting of a β resin component.

[Conventional technology]

Coal tar pitch, which is obtained from coal tar that is a by-product when carbonizing coal to produce coke, is used as a binder for briquette coal used in coke production, as a caking filler for coal, as a raw material for carbon fiber production, and as a raw material for needle coke production. It is used as a raw material for manufacturing various carbon materials, such as binders used in manufacturing electrodes for aluminum elaboration, raw materials for pitch coke manufacturing, raw materials for manufacturing graphite materials for nuclear reactors, and the demand for it is increasing year by year. are doing.

However, coal tar pitch contains a so-called (l component) that is not dissolved in quinoline and is composed of free carbon, ash, and other inorganic substances. Various problems occur, such as thread breakage and deterioration of coking and graphitizing properties, and as a result, it is impossible to produce a high-quality carbon material.

Methods for removing QI components include adding a solvent to coal tar pitch, stirring and mixing to dissolve the solvent-soluble content in the coal tar pitch, and separating the solvent-insoluble content by static separation, centrifugation, filtration, etc. JP-A-60-691 discloses a method of separating the solvent and removing the solvent from the obtained solvent solution of the solvent-soluble component.
Publication No. 95, Japanese Patent Publication No. 59-10716, Japanese Patent Application Publication No. 1983
0=described in Publication No. 72983 and the like.

The purified coal tar pitch from which the QIl component has been removed consists of ash that is soluble in toluene (hereinafter referred to as TS component) and TI-QS component (beta resin component) that is insoluble in toluene and soluble in quinoline. β-resin components are attracting attention as raw materials for high value-added carbon products.

However, a method for efficiently and stably fractionating these TS components and β-resin components at high concentrations has not yet been developed.

Jikai fff156-18688 describes a method for separating asphaltenes from asphaltene-containing heavy hydrocarbon materials, and JP-A-57-78489 describes a method for separating asphaltenes and resin from bituminous materials. Are listed.

However, asphaltene contains TS along with the β-resin component.
components are also included, and there is no description of how to separate these two.

JP-A No. 60-51782 discloses a β-resin component [BI
(Benzene insoluble matter - toluene insoluble matter (Tl)) ・Q
[S component] This relates to a method for producing QI Respitch with an adjusted amount, including aromatic solvents with a boiling point of 180°C or less such as benzene and toluene, or mixed solvents thereof, and boiling points obtained from light oil or coke oven gas whose main components are benzene and toluene. After mixing coal tar or pitch with gas light extraction mainly composed of components below 250°C, the mixture is heated to a temperature of 150°C.
℃ or above and a pressure of 5 al1 or above to separate light oil produced by gravity sedimentation from ffiura. It only has the effect of reducing β component) in the obtained QIless pitch
The content of the resin component does not greatly exceed the content of the β resin component in the raw material, and it is not possible to obtain a high concentration of the β resin component, for example, 50 T'Tm% or more.

The purpose of the present invention is to use coal-based pitch, especially pitch obtained by distilling coal tar, which is a by-product during coal carbonization, as a raw material, and by removing 91 minutes, the β-resin component can be efficiently and stably produced at a high concentration. The object of the present invention is to provide a method for fractionation.

[Means to solve the problem]

The present invention introduces coal tar pitch, a first aromatic solvent, and an aliphatic solvent into a first separation zone, and
Mix and hold in a temperature range of 0°C to form a low specific gravity liquid and Q! The high specific gravity liquid is phase separated from the high specific gravity liquid mainly composed of the 戊 component, the low specific gravity liquid and the high specific gravity liquid are extracted separately, and then the solvent of the low specific gravity liquid is removed, and then the solvent is removed. Liquid II and a second aromatic solvent are introduced into a second fractionation zone, and the temperature is between the critical temperature of the solvent introduced into the second fractionation zone and 370°C, and the pressure is between the critical pressure of the solvent and 100 kg. TS
A method for fractionating β-resin, which is characterized by phase-separating into a low-density liquid mainly consisting of a component and a high-density liquid mainly consisting of a β-resin, and extracting the low-density liquid and the high-density liquid separately. be.

When mixing coal tar pitch, aromatic solvent, and aliphatic solvent in the first separation zone, the mixing ratio (coal tar pitch ffi/mixed solvent ff1), (aromatic solvent/
It is preferable to adjust the amount of the β-resin component in the low-density liquid by keeping one or both of the blending ratio (aliphatic solvent) and blending temperature constant and increasing or decreasing the others.

Further, in the second separation zone, it is preferable to adjust the amount of the β-resin component by increasing/decreasing the solvent/pitch blending ratio, temperature, and pressure.

As coal tar pitch, pitch with a softening point of 100° C. or less obtained by distilling coal tar by-produced during coal carbonization, particularly soft pitch with a softening point of 70° C. or less is preferable.

The present invention uses two types of solvents with different extraction behaviors to perform a two-stage fractionation operation under different operating conditions.
In this step, fractionation operations are performed under supercritical conditions of the solvent used.

This will be explained in detail with reference to the process flow sheet shown in FIG.

A first fractionating column 1 is provided as a first fractionating zone, and a ff12 fractionating column 2 is provided as a second fractionating zone. Coal tar pitch from line 4, first aromatic solvent and aliphatic solvent from line 5, A mixed solvent consisting of system solvents is mixed in a mixer 6,
It is maintained under conditions ranging from room temperature to 150°C and separated into a low specific gravity liquid and a high specific gravity liquid mainly containing QI acid components. Separately draw out the high density liquid.

As the first aromatic solvent, a solvent whose main component is an aromatic hydrocarbon having a boiling point or a 95% distillation temperature of 220 to 360°C is suitable. , Antrasenura, Pitchura, Absorption Department (
A multi-component heavy extraction containing at least IFli selected from the group consisting of Coker Ura, which is a by-product when producing sitting pitch coke by the delayed coker method, has a high solubility in coal tar pitch and a low temperature. It is preferred because it provides a solution with low viscosity and is easily available.

As the aliphatic solvent, a solvent whose main component is an aliphatic hydrocarbon with a boiling point or 95% distillation temperature of 220 to 300°C is suitable, but Ishiura naphtha, industrial gasoline, Uchibe, Ishiura type At least 1ff selected from the group consisting of Karuura
[A multi-component solvent containing i is preferred in terms of availability and cost.

Although FIG. 1 shows the case where the coal tar pitch and the solvent are mixed and then heated, the coal tar pitch and the solvent may be heated separately and then mixed.

Further, as for the mixer 6, a line mixer, an agitation mixer, etc. can be used, but the lines may simply be merged without installing the mixer 6.

Regarding the mixing temperature, when a large amount of aromatic solvent is used, mixing can be performed at room temperature, but the temperature is preferably 80° C. or higher. The upper limit is 150° C. or lower from the point of generation of solvent vapor.

In this first stage fractionation operation, the QI acid component is extracted as a high specific gravity liquid, while the TS component from which the QI component has been removed and the β
The resin component is extracted as a low specific gravity liquid.

When mixing coal tar pitch, aromatic solvent, and aliphatic solvent in the first separation zone, the blending ratio of coal tar pitch (amount of coal tar, buty/amount of mixed solvent), the blending ratio in the mixed solvent (aromatic The amount of the β resin component in the low specific gravity liquid can be adjusted by keeping one or both of the compounding temperature (group solvent/aliphatic solvent) constant and increasing or decreasing the others.

It is better to increase the blending ratio of coal tar pitch, increase the blending ratio of aromatic solvent in the solvent, or raise the blending temperature.
It is possible to increase the amount of TI/QS components, ie, the amount of β-resin component, in the low ratio ffl liquid.

The low specific gravity liquid extracted from the first fractionating column low specific gravity liquid extraction line 8 is introduced into the first fractionating column low specific gravity liquid distillation column 3, where the low specific gravity liquid is distilled and the solvent is removed from the first solvent extraction line 9 at the top of the column. The main component is distilled and reused as a solvent.

The tower bottom is then mixed with the second aromatic solvent supplied through the second solvent supply line 11 through the second fractionation tower coal tar pitch supply line 10 in a mixer 12 and introduced into the second fractionation tower 2. do.

The second aromatic solvent is preferably C-C9 bezozene or alkylbenzene, and more preferably at least one solvent or mixed solvent selected from the group consisting of benzene, toluene, xy, and lene. good.

The critical temperature of benzene is 289℃, and the critical pressure is 49kg/
cJG,) The critical temperature of luene is 319°C, and the critical pressure is 4
0 kg/cjG, the critical temperature of xylene is 343°C, and the critical pressure is 36 kg/cd G.

The column bottom and the second aromatic solvent may be heated before being fed into the mixer 12, or may be heated downstream of the mixer 12.

In the second fractionation column, the temperature ranges from the critical temperature of the solvent to 370°C,
critical pressure of the solvent to 100 kg/cdGO) and a blending ratio of (second aromatic solvent/coal tar pitch component entering the second fractionation zone) 0. 5 to 5, phase separation is performed into a low specific gravity liquid mainly consisting of TS components and a high specific gravity liquid mainly consisting of β-resin, and the low specific gravity liquid is passed through line 13 from the top of the column and from the bottom of the column. The high density liquid is drawn off separately via line 14.

Here, the yield and concentration of the β-resin component amount can be adjusted by keeping one or both of the temperature, pressure, and second aromatic solvent blending ratio constant and increasing or decreasing the others. That is, the higher the temperature, the lower the pressure, and the higher the blending ratio of the second aromatic solvent, the higher the yield of the β-resin component.

In this second-stage separation operation, components mainly consisting of TS are extracted as a low-density liquid, and components containing a high concentration of β-resin component are extracted as a high-density liquid. Finally, by removing the solvent from the low specific gravity liquid extracted from the second fractionation column through line 13 (the device is not shown), the TS component is recovered, and the QI acid component and TS component in the coal tar pitch used as the raw material are recovered. The β-resin component can be separated and recovered.

It is economically preferable to recover and recycle the removed solvent.

〔Example〕

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the same extent by these Examples.

(Example 1) As raw material coal tar pitch, ↑S component 90% by weight,
β resin component 8.5% by weight and QI acid component 5% by weight
The first aromatic solvent was coker light oil, which is produced as a by-product in the delayed coker during pitch coke production, and the aliphatic solvent was kerosene. using toluene as an aromatic solvent,
According to the flow sheet shown in FIG. 1, the β-resin component in the soft pitch was fractionated.

The operating conditions for the first fractionation column were as follows: A soft pitch preheated to 120°C was sent from line 5 using a pitch feed pump, and a mixed solvent of coker light oil and kerosene was sent from line 4 at room temperature using a solvent feed pump. .

The blending ratio of coal tar pitch, aromatic solvent, and aliphatic solvent was 50:25:25, and they were mixed in a mixer (line mixer) 6, and the mixture was heated in a heater at 1.
The mixture is heated to 20°C, then introduced into the first fractionation column 1 and maintained at 120°C to separate the low specific gravity liquid and the high specific gravity liquid into the high specific gravity liquid via line 7 from the bottom of the column. The liquid, ie, the raffinate phase mainly consisting of Qr acid components, was extracted, and a low specific gravity liquid was extracted through line 8 from the top of the column.

The low specific gravity liquid extracted from the top of the first fractionation column was introduced into the distillation column and distilled at a cut point of 315° C., and the mixed solvent was extracted from line 9 and the solvent-removed pitch was extracted from the bottom of the column.

The low specific gravity liquid from the first fractionation column from which the solvent has been removed is pumped through line 1o by a pitch feed pump, and the toluene is
Solvent IJ was fed under pressure to line 11 using a feed pump while still at 1 temperature.The ffItil ratio of toluene and low density liquid was 1:3.
Mix in mixer 12 as O and heat the mixture in heater 340.
℃, then this mixture was introduced into the second fractionation column 2 and maintained under the conditions of temperature 340''C1 pressure force 60 kg/cl G to phase separate into a low specific gravity liquid and a high specific gravity liquid, and the column A high-density !rr liquid, that is, a raffinate phase consisting mainly of β resin components, was extracted from the bottom line 14, and a low specific gravity liquid was extracted from the top of the column through line 13, and the solvent was removed by distillation.

When the amount and composition of the product was determined a+++, it was found that the high specific gravity liquid extracted from the bottom of the first fractionation column. I component to 15
Insoluble pitch containing % by weight (10ffl amount % based on raw materials)
), β is extracted from the high density liquid extracted from the bottom of the second fractionation column.
Pitch (concentration of 800% by weight or more) consisting mainly of resin components (
TS component-based pitch (85% by weight relative to the raw material) was recovered from the low specific gravity liquid extracted from the top of the second fractionation column.

(Example 2) The first stage fractionation operation is the same as in Example 1, and the second stage fractionation operation is performed to separate toluene and low specific gravity liquid! I! Only Et ratio is 1. :
2. The fractionation operation was performed as O. When the amount and composition of the product was measured, it was found that the high density liquid extracted from the bottom of the first fractionation column contained insoluble pitch containing 15ffI amount of QI components (10% by weight relative to the raw material), and the high density liquid extracted from the bottom of the first fractionation column. The high-density liquid extracted from the bottom of the tower contains mainly β-resin components (content: 8
7% by weight or more) pitch (2.5% by weight relative to the raw material), and TS-based pitch (87.5% by weight relative to the raw material) was recovered from the low specific gravity liquid extracted from the top of the second fractionation column. .

〔Effect of the invention〕

According to the method of the present invention, a β-resin component, which is a raw material for high-value-added carbon products, can be efficiently and stably fractionated at a high concentration using a simple device and operation. Further, by adjusting the blending ratio of the coal tar pitch mixed solvent, the blending ratio of the aromatic solvent to the aliphatic solvent, and the blending temperature, the yield and purity of the β-resin can be controlled to the r1 peak.

[Brief explanation of drawings]

FIG. 1 is a process flow chart of an example of a device suitable for carrying out the method of the present invention.・Indicates. DESCRIPTION OF SYMBOLS 1... First fractionation column, 2... Second fractionation column, 3... First fractionation column, low specific gravity liquid distillation column, 4... Coal tar pitch supply line, 5... First solvent supply Line, 6... Mixer, 7... First fractionation tower high specific gravity liquid extraction line, 8
. . . 1st fractionating tower low specific gravity liquid extraction line, 9 . . . 1st solvent extraction line, 10 . . . 2nd fractionating tower coal tar pitch supply line, 11 . . . 12...Mixer, 13...Low specific gravity liquid extraction line from the second fractionating tower, 4...High specific gravity liquid extraction line from the second fractionation tower.Deputy representative Fujiki1.7 Hikaru

Claims (1)

[Claims] 1. Coal tar pitch, a first aromatic solvent, and an aliphatic solvent are introduced into the first separation zone, and the temperature is increased from room temperature to 150°C.
℃ temperature range to phase separate the low specific gravity liquid and the high specific gravity liquid mainly composed of QI components, the low specific gravity liquid and the high specific gravity liquid are extracted separately, and then the solvent for the low specific gravity liquid is removed. After removal, the desolventized low density liquid and the second aromatic solvent are introduced into the second fractionation zone, and the temperature is between the critical temperature of the solvent introduced into the second fractionation zone and 370°C, and the pressure is critical pressure of the solvent to 100 kg/cm^2G, and (second aromatic solvent/coal tar pitch component entering the second fractionation zone)
A weight ratio of 0.5 to 5 is maintained to phase-separate the low specific gravity liquid mainly consisting of the TS component and the high specific gravity liquid mainly consisting of β-resin, and the low specific gravity liquid and the high specific gravity liquid are separated. A method for fractionating β-resin, which comprises separately extracting the β-resin.