阅读说明：本技术 一种改质沥青、沥青焦及其制备方法和应用 (Modified asphalt, asphalt coke, and preparation method and application thereof ) 是由 沈龙 范拯华 张秀云 陈兵帅 于 2020-12-25 设计创作，主要内容包括：本发明公开了一种改质沥青、沥青焦及其制备方法和应用。改质沥青的制备方法包括如下步骤：将煤沥青和同多钒酸盐催化剂经氧化交联反应,制得改质沥青。本发明的改质沥青经缩聚和焦化反应得到的沥青焦具有细镶嵌结构和各向同性,内部结构均匀,无局部结焦现象发生,原料成本低,沥青焦挥发分低,工艺简单,可操作性强,反应过程绿色环保,可满足锂离子电池负极材料的特性需求。(The invention discloses modified asphalt, asphalt coke, and a preparation method and application thereof. The preparation method of the modified asphalt comprises the following steps: the coal tar pitch and the poly-vanadate catalyst are subjected to oxidation crosslinking reaction to prepare the modified pitch. The pitch coke obtained by the modified pitch through polycondensation and coking has a fine mosaic structure and isotropy, an internal structure is uniform, a local coking phenomenon is avoided, the raw material cost is low, the volatile component of the pitch coke is low, the process is simple, the operability is high, the reaction process is green and environment-friendly, and the characteristic requirements of the lithium ion battery cathode material can be met.)

1. The preparation method of the modified asphalt is characterized by comprising the following steps: the coal tar pitch and the poly-vanadate catalyst are subjected to oxidation crosslinking reaction to prepare the modified pitch.

2. The process for producing modified pitch according to claim 1, wherein the coal pitch is coal pitch having a softening point of 70 ℃ or lower, preferably 60 to 70 ℃;

and/or the isopolyvanadate catalyst contains V₄O₁₂ ^4-、V₁₀O₂₆ ^4-And V₁₀O₂₈ ^6-The catalyst is an isopolyvanadate catalyst containing one or more polyoxovanadate anions, preferably (NH)₄)₄V₄O₁₂·2H₂O、(NH₄)₄V₁₀O₂₆·6H₂O and (NH)₄)₆V₁₀O₂₈·6H₂One or more of O;

and/or the mass ratio of the coal pitch to the isopolyvanadate catalyst is 1: (0.001 to 0.005), preferably 1: (0.002-0.005).

3. The process for producing an upgraded asphalt according to claim 1 or 2, wherein the oxidative crosslinking reaction is carried out in a reactor having an air distributor at the bottom;

and/or the oxidative crosslinking reaction is carried out under air and/or oxygen; the flow rate of the air and/or the oxygen is preferably 10 to 50L/h, more preferably 10 to 20L/h;

and/or the temperature of the oxidation crosslinking reaction is 340-380 ℃, preferably 360-380 ℃;

and/or the time of the oxidation crosslinking reaction is 1-6 h, preferably 3-6 h;

and/or heating the system to the temperature of the oxidative crosslinking reaction at a heating rate of 3-10 ℃/min.

4. An improved asphalt produced by the method for producing an improved asphalt according to any one of claims 1 to 3.

5. A process for producing an asphalt coke, which comprises reacting the modified asphalt of claim 4 in an inert atmosphere; the reaction is cracking polycondensation reaction and coking reaction.

6. The method for preparing the pitch coke according to claim 5, wherein the reaction temperature is 490-500 ℃;

and/or the reaction time is 3-6 h;

and/or heating the system to the reaction temperature at a heating rate of 3-10 ℃/min;

and/or the inert atmosphere is nitrogen;

and/or the flow rate of the inert atmosphere is 0.5-1.5L/h, preferably 1L/h.

7. An asphalt coke produced by the method for producing an asphalt coke according to claim 5 or 6.

8. The pitch coke of claim 7, wherein the pitch coke has a volatile content of less than 7%, preferably 5.1%, 5.5%, 6.0%, 6.2% or 6.5%.

9. The use of the pitch coke according to claim 7 or 8 as a raw material in the field of preparation of lithium ion battery negative electrode materials.

10. The application of an isopolyvanadate catalyst in catalyzing coal tar pitch to generate oxidation crosslinking reaction;

preferably, the isopolyvanadate catalyst is the isopolyvanadate catalyst described in claim 1 or 2.

Technical Field

The invention relates to modified asphalt, asphalt coke, and a preparation method and application thereof.

Background

The coal pitch has the characteristics of rich resources, low price, high carbon content, good fluidity, easy graphitization and the like, and is one of the most important and basic matrix precursors in the production of various carbon materials. Coal tar pitch is very complex in structure and composition, consists of a large number of highly condensed carbocyclic and heterocyclic compounds, has a composition and structure homologous to coal, but differs in the degree of ring formation and molecular composition, and has a wide molecular weight distribution range. With the more and more diversified special requirements of the lithium ion battery terminal application subdivision field, the negative electrode material prepared based on the coal tar pitch is also gradually valued. Due to the complex molecular structure and composition of the coal tar pitch, natural possibility is provided for preparing the negative electrode material with special performance.

In the prior art, for the preparation of pitch coke based on coal tar pitch, the raw material is usually converted into high molecular weight compounds by means of oxygen or air oxidation or thermal polymerization, or the low molecular weight compounds are removed by oxidative polymerization combined with vacuum distillation to obtain the pitch with the expected softening point, or the pitch at the bottom of the tar distillation tower is blended with heavy oil to obtain the cycle oil. And carrying out carbonization cracking and condensation reaction on the raw materials at a certain temperature to obtain the pitch coke. However, the method generally has the phenomena of local coking of the product, uneven internal structure of the product, high content of volatile components and incapability of being used in the field of high-performance lithium ion battery cathode materials.

Therefore, there is a need in the art to develop an asphalt coke having a uniform internal structure, low volatile content and a simple process, which can be used for preparing a lithium ion negative electrode material.

Disclosure of Invention

The invention aims to overcome the defects that the asphalt coke in the prior art generally has a local coking phenomenon, the internal structure of a product is not uniform, the content of volatile components is high, and the asphalt coke cannot be used in the field of high-performance lithium ion battery cathode materials, and the like, and provides modified asphalt, the asphalt coke and preparation methods and applications thereof. The asphalt coke prepared by the method has a fine mosaic structure and isotropy, is uniform in internal structure, free of local coking phenomenon, low in raw material cost, low in asphalt coke volatile component, simple in process, strong in operability, green and environment-friendly in reaction process, and can meet the characteristic requirements of the lithium ion battery cathode material.

The invention provides a preparation method of modified asphalt, which comprises the following steps: the coal tar pitch and the poly-vanadate catalyst are subjected to oxidation crosslinking reaction to prepare the modified pitch.

In the present invention, the coal pitch may be coal pitch having a softening point of 70 ℃ or lower, preferably 60 to 70 ℃, which is conventionally used in the art.

In the present invention, the isopolyvanadate catalyst preferably contains V₄O₁₂ ^4-、V₁₀O₂₆ ^4-And V₁₀O₂₈ ^6-The catalyst is one or more isopolyvanadate catalyst of polyvanadate anion, further preferably (NH)₄)₄V₄O₁₂·2H₂O、(NH₄)₄V₁₀O₂₆·6H₂O and (NH)₄)₆V₁₀O₂₈·6H₂One or more of O.

In the present invention, the mass ratio of the coal tar pitch and the isopolyvanadate catalyst may be conventional in the art, and is preferably 1: (0.001 to 0.005), preferably 1: (0.002-0.005).

In the present invention, the conditions and method of the oxidative crosslinking reaction may be those conventional in the art for such reactions, and are generally carried out in a reactor having an air distributor at the bottom. The reactor provided with the air distributor can fully stir the coal tar pitch and the isopolyvanadate catalyst, and is favorable for the uniformity of the oxidation crosslinking reaction.

In the present invention, the oxidative crosslinking reaction may be carried out under air and/or oxygen as is conventional in the art. The flow rate of the air and/or the oxygen may be conventional in the art, and is preferably 10 to 50L/h, more preferably 10 to 20L/h.

In the present invention, the temperature of the oxidative crosslinking reaction may be a temperature conventional in the art, and is preferably 340 to 380 ℃, more preferably 360 to 380 ℃.

In the present invention, the time of the oxidative crosslinking reaction can be the time of the conventional reaction in the field, preferably 1 to 6 hours, and more preferably 3 to 6 hours.

In the invention, the heating rate for heating the system to the temperature of the oxidative crosslinking reaction can be the conventional heating rate of the reaction in the field, and is preferably 3-10 ℃/min.

The invention also provides modified asphalt prepared by the preparation method of the modified asphalt.

The invention also provides a preparation method of the asphalt coke, which comprises the following steps: reacting the modified asphalt in an inert atmosphere; the reaction is cracking polycondensation reaction and coking reaction.

In the present invention, the conditions and methods of the reaction may be those conventional in the art for subjecting the upgraded asphalt to the cracking polycondensation reaction and the coking reaction.

In the present invention, the reaction temperature may be a temperature conventional in the art, and is preferably 490 to 500 ℃.

In the invention, the reaction time can be the time conventional in the reaction in the field, and is preferably 3-6 h.

In the invention, the heating rate for heating the system to the reaction temperature can be the conventional heating rate of the reaction in the field, and is preferably 3-10 ℃/min.

In the present invention, the inert atmosphere may be an inert atmosphere which is conventionally considered by those skilled in the art to be chemically unreactive with the upgraded asphalt, and is preferably nitrogen.

In the present invention, the flow rate of the inert atmosphere can be conventional in the art, and is preferably 0.5 to 1.5L/h, and more preferably 1L/h.

The invention also provides the asphalt coke prepared by the preparation method of the asphalt coke.

In the present invention, the content of volatile components in the pitch coke may be generally 7% or less, for example, 5.1%, 5.5%, 6.0%, 6.2% or 6.5%.

The invention also provides application of the asphalt coke as a raw material in the field of preparation of lithium ion battery cathode materials.

The invention also provides an application of the isopolyvanadate catalyst in catalyzing coal tar pitch to generate oxidation crosslinking reaction.

Wherein the isopolyvanadate catalyst may be an isopolyvanadate catalyst as described above.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows: the coal tar pitch is used as a raw material, the coal tar pitch with a fine mosaic structure and isotropy is prepared by means of an isopolyvanadate catalyst according to the principle of oxidative crosslinking and cracking polycondensation of a high molecular compound, the internal structure is uniform, the local coking phenomenon is avoided, the coal tar pitch with the softening point of below 70 ℃ is used as the raw material, the reaction is rapid, the preparation cost is reduced, the volatile content of the coal tar pitch is low, the process is simple, the operability is high, the reaction process is green and environment-friendly, and the characteristic requirements of the lithium ion battery cathode material can be met.

Drawings

FIG. 1 is a photograph of a polarized light of the pitch coke obtained in example 1.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

Example 1

Mixing coal tar pitch with softening point of 60 deg.C and isopolyvanadate catalyst (NH)₄)₄V₄O₁₂·2H₂O, and the mass ratio of 1: mixing at 0.001 ratio, adding into a reactor with reflux unit and air distributor at bottomIntroducing air with the air flow rate of 10L/h, heating to 340 ℃ at the heating rate of 3 ℃/min, and keeping the temperature for 1h at the temperature of 340 ℃. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow rate of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the constant temperature for 3h at the temperature of 490 ℃ to obtain the pitch coke. FIG. 1 is a polarized photograph of the obtained pitch coke, and it can be seen from FIG. 1 that the prepared pitch coke has a fine mosaic structure, and has the characteristics of isotropy, uniform internal structure and no local coking phenomenon.

Example 2

Mixing coal tar pitch with softening point of 60 deg.C and isopolyvanadate catalyst (NH)₄)₄V₄O₁₂·2H₂O, and the mass ratio of 1: mixing at a ratio of 0.002, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow of 10L/h, heating to 340 ℃ at a heating rate of 3 ℃/min, and keeping the temperature at 340 ℃ for 3 h. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow rate of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the temperature at 490 ℃ for 6h to obtain the pitch coke.

Example 3

Mixing coal tar pitch with softening point of 60 deg.C and isopolyvanadate catalyst (NH)₄)₄V₁₀O₂₆·6H₂O, and the mass ratio of 1: mixing at a ratio of 0.002, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow rate of 20L/h, heating to 340 ℃ at a heating rate of 3 ℃/min, and keeping the temperature at 340 ℃ for 1 h. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow rate of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the constant temperature for 3h at the temperature of 490 ℃ to obtain the pitch coke.

Example 4

Mixing coal tar pitch with softening point of 60 deg.C and isopolyvanadate catalyst (NH)₄)₄V₁₀O₂₆·6H₂O, and the mass ratio of 1: mixing at 0.002 ratio, adding into a reverse mixer with reflux unit and air distributor at bottomAir is introduced into the reactor, the air flow is 20L/h, the temperature is increased to 340 ℃ at the heating rate of 3 ℃/min, and the temperature is kept for 3h at the temperature of 340 ℃. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow rate of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the constant temperature for 3h at the temperature of 490 ℃ to obtain the pitch coke.

Example 5

Mixing coal tar pitch with softening point of 70 ℃ and an isopolyvanadate catalyst (NH)₄)₄V₁₀O₂₆·6H₂O, and the mass ratio of 1: mixing at a ratio of 0.002, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow rate of 20L/h, heating to 340 ℃ at a heating rate of 3 ℃/min, and keeping the temperature at 340 ℃ for 1 h. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow rate of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the constant temperature for 3h at the temperature of 490 ℃ to obtain the pitch coke.

Example 6

Mixing coal tar pitch with softening point of 70 ℃ and an isopolyvanadate catalyst (NH)₄)₄V₁₀O₂₆·6H₂O, and the mass ratio of 1: mixing at a ratio of 0.005, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow of 20L/h, heating to 360 deg.C at a heating rate of 3 deg.C/min, and keeping the temperature at 360 deg.C for 6 h. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the temperature at 490 ℃ for 6h to obtain the pitch coke.

Example 7

Mixing coal tar pitch with softening point of 70 ℃ and an isopolyvanadate catalyst (NH)₄)₄V₁₀O₂₆·6H₂O, and the mass ratio of 1: mixing at a ratio of 0.005, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow of 20L/h, heating to 360 deg.C at a heating rate of 3 deg.C/min, and keeping the temperature at 360 deg.C for 6 h. Stopping introducing air after constant temperature is over, switching to introducing nitrogen and nitrogenThe flow rate is 1L/h, the reactor is continuously heated to 500 ℃ at the heating rate of 3 ℃/min, and the temperature is kept constant for 3h at the temperature of 500 ℃ to obtain the pitch coke.

Example 8

Mixing coal tar pitch with softening point of 70 ℃ and an isopolyvanadate catalyst (NH)₄)₆V₁₀O₂₈·6H₂O, and the mass ratio of 1: mixing at a ratio of 0.005, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow of 20L/h, heating to 360 deg.C at a heating rate of 3 deg.C/min, and keeping the temperature at 360 deg.C for 6 h. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow of 1L/h, continuously heating the reactor to 500 ℃ at the heating rate of 3 ℃/min, and keeping the temperature at the temperature of 500 ℃ for 6h to obtain the pitch coke.

Comparative example 1

Adding coal pitch with a softening point of 60 ℃ into a reactor with a reflux device and an air distributor arranged at the bottom, introducing air with the air flow of 10L/h, heating to 340 ℃ at the heating rate of 3 ℃/min, and keeping the temperature for 1h at the temperature of 340 ℃. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the constant temperature for 3h at the temperature of 490 ℃ to obtain the pitch coke.

Comparative example 2

Adding coal pitch with a softening point of 60 ℃ into a reactor with a reflux device and an air distributor arranged at the bottom, introducing air with the air flow of 10L/h, heating to 340 ℃ at the heating rate of 3 ℃/min, and keeping the temperature for 3h at the temperature of 340 ℃. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow of 1L/h, continuously heating the reactor to 490 ℃ at the heating rate of 3 ℃/min, and keeping the temperature at 490 ℃ for 6h to obtain the pitch coke.

Comparative example 3

Mixing coal tar pitch with softening point of 70 ℃ and catalyst AlCl₃According to the mass ratio of 1: mixing at a ratio of 0.005, adding into a reactor with reflux unit and air distributor at the bottom, introducing air with flow rate of 20L/h, heating to 360 deg.C at a heating rate of 3 deg.C/min, and heating at 360 deg.CKeeping the temperature constant for 6 hours. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow of 1L/h, continuously heating the reactor to 500 ℃ at the heating rate of 3 ℃/min, and keeping the temperature at the temperature of 500 ℃ for 6h to obtain the pitch coke.

Comparative example 4

Mixing coal tar pitch with softening point of 60 deg.C and isopolyvanadate catalyst (NH)₄)₄V₄O₁₂·2H₂O, and the mass ratio of 1: mixing at a ratio of 0.002, adding into a reactor with a reflux device, introducing nitrogen gas with a flow rate of 1L/h, heating to 340 ℃ at a heating rate of 3 ℃/min, and keeping the temperature at 340 ℃ for 3 h. After the constant temperature is finished, the reactor is continuously heated to 490 ℃ at the heating rate of 3 ℃/min, and the temperature is kept constant at 490 ℃ for 6 hours to obtain the asphalt coke.

Comparative example 5

Mixing coal tar pitch with softening point of 70 deg.C and molecular formula of [ NH ]₄]₃[PMo₁₂O₄₀]·M₂O catalyst according to the mass ratio of 1: mixing at a ratio of 0.005, adding into a reactor with a reflux device and an air distributor at the bottom, introducing air with an air flow of 20L/h, heating to 360 deg.C at a heating rate of 3 deg.C/min, and keeping the temperature at 360 deg.C for 6 h. And stopping introducing air after the constant temperature is over, switching to introducing nitrogen with the nitrogen flow of 1L/h, continuously heating the reactor to 500 ℃ at the heating rate of 3 ℃/min, and keeping the temperature for 3h at the temperature of 500 ℃ to obtain the pitch coke.

Effects of the embodiment

The volatile contents of the pitch cokes prepared in the above examples and comparative examples were measured, and the results are shown in table 1. The determination method of the volatile content refers to a volatile test method in YB/T5189-2007 "determination of carbon material volatile".

FIG. 1 is a photograph of a polarized light of the asphalt coke obtained in example 1, which was observed under a polarizing microscope of Axio Scope A1 pol type manufactured by Zeiss, Germany.

TABLE 1

Numbering	Volatile content/%
		Example 1	7.0
Example 2	6.2
		Example 3	6.5
Example 4	6.0
		Example 5	6.5
Example 6	5.5
		Example 7	6.2
Example 8	5.1
		Comparative example 1	9.5
Comparative example 2	8.6
		Comparative example 3	40.2
Comparative example 4	30.6
		Comparative example 5	35.6

As can be seen from Table 1, the pitch coke prepared by the invention has lower volatile components, which shows that coal pitch is subjected to sufficient oxidative crosslinking and cracking polycondensation reaction under the catalyst system of the invention, mesophase spherules are not further grown and fused and oriented, and the obtained pitch coke has the characteristics of fine mosaic structure and low volatile components.