CN112744804B - Method for preparing carbon material from heavy oil slurry - Google Patents

Abstract

The invention relates to the field of heavy oil slurry treatment, and discloses a method for preparing a carbon material from heavy oil slurry, which comprises the following steps: a. carbonizing a mixture of heavy oil slurry and ferric salt in an inert atmosphere to obtain pyrolysis gas and a porous carbon material; b. condensing the cracked gas; c. carrying out catalytic cracking on the oil gas component with the boiling point of below 50 ℃ obtained by condensation to obtain a carbon nano material; wherein the distillation range of the heavy oil slurry is more than 500 ℃, the colloid content of the heavy oil slurry is 10-40 wt%, the asphaltene content of the heavy oil slurry is 5-20 wt%, and the solid content of the heavy oil slurry is 2-7g solid/L oil slurry. The method provides a two-stage cracking technology, so that non-ideal heavy components contained in heavy oil slurry can be utilized, and various nano carbon materials with higher values can be produced.

Description

Method for preparing carbon material from heavy oil slurry

technical field

The invention relates to the field of heavy oil slurry treatment, in particular to a method for preparing carbon materials from heavy oil slurry.

Background technique

In the fluid catalytic cracking process of petroleum refining, in order to control the coke formation rate and the solid content of the oil slurry in the fluid catalytic cracking unit, to ensure the safe and stable operation of the unit and the distribution and quality of the product, a part of the oil slurry is usually thrown out. The distillation range of the external oil slurry is generally higher than 350°C, the solid content and the content of polycyclic aromatic hydrocarbons are relatively high, it is easy to coke, and the cracking performance is poor. Therefore, the treatment and comprehensive utilization of the external oil slurry is a problem that the refinery needs to solve. The flung oil slurry can be directly used as a blending component of fuel oil, and can also be sent to a delayed coking unit together with residual oil. Although it is easy to operate, it has low utilization value. Moreover, with the improvement of environmental protection requirements, fuel oil and coke with high sulfur content cannot be sold. In addition, high solid content of oil slurry will cause blockage of fuel pipeline and high content of coke ash. According to its composition characteristics, after pretreatment and separation, the oil slurry can be used for other purposes. The key to desolidification of oil slurry is the removal of catalyst powder, mainly through sedimentation method, electrostatic separation method and filtration method.

In order to increase the added value of the product, the oil slurry can also be coked to produce needle coke. Needle coke is a high-quality petroleum coke with metallic luster and fibrous texture. It has the characteristics of easy graphitization, low thermal expansion, high conductivity, low ash, and low sulfur. It is ideal for preparing high power (HP) and ultra-high power ( The main raw material of UHP) graphite electrode. With the development of electric vehicles, needle coke is also used as a negative electrode raw material for lithium-ion batteries. However, the preparation of needle coke has more stringent requirements on the raw materials and process, so the oil slurry must be separated, and the separated rich saturated and light aromatic components can be mixed into catalytic cracking raw materials, and the rich aromatic components can be used as raw materials for Production of needle coke, colloid-rich, asphaltene components, etc. can be used to blend road asphalt. According to the different uses of oil slurry, there are different methods to separate components or remove asphalt, such as solvent extraction, residual oil hydrogenation, vacuum distillation, ionic liquid supercritical extraction, etc.

CN1872963A discloses a two-step method of vacuum distillation and hydrogenation to pretreat needle coke raw materials, which can remove non-ideal components in raw oil, while keeping the content of ideal components with short side chains and few ring aromatics without decreasing. Among them, the non-ideal components include light saturated hydrocarbons, gums and asphaltenes, and most of the gums and asphaltenes are in the heavy oil slurry components with a distillation range >500°C.

CN106883871A discloses a method for producing needle coke raw materials through a combined process of visbreaking treatment and solvent deasphalting treatment. The raw material mixed with the catalyst is heated by a heating furnace and enters the visbreaking reactor, and then enters the fractionating tower to fractionate the dry gas, gasoline fraction and visbreaking heavy components. , Deoiled asphalt as a blending component of asphalt.

CN103013567A discloses a method of setting a protection zone before hydrogenation to filter out most of the catalytic cracking catalyst powder entrained in the catalytic cracking oil slurry, realize long-term operation, and produce qualified needle coke raw materials.

CN1382761A discloses a method for extracting catalytic cracking clarified oil from lubricating oil extract. The extracted oil containing catalyst powder is used together with residual oil raw materials to produce ordinary petroleum coke, or used as fuel oil, and the lubricating oil extract is recovered to produce acicular coke. Coke beneficial aromatic components.

However, the above patents all need to be based on the premise of optimizing needle coke raw materials. There is no good way to deal with the non-ideal components, and the non-ideal heavy components are only used for asphalt blending and so on.

Contents of the invention

The purpose of the present invention is to solve the problem of how to realize the high value-added processing of non-ideal components in the oil slurry produced by catalytic cracking, and to provide a method for preparing carbon materials from heavy oil slurry, which can make heavy The non-ideal components in oil slurry can be utilized with high added value.

In order to achieve the above object, the present invention provides a method for preparing carbon material from heavy oil slurry, comprising:

a. Under an inert atmosphere, carbonize the mixture of heavy oil slurry and iron salt to obtain cracked gas and porous carbon materials;

b. Condensing the cracked gas;

c. Catalytic cracking of the oil and gas components obtained by the condensation with a boiling point temperature below 50° C. to obtain carbon nanomaterials;

Wherein, the distillation range of the heavy oil slurry is >500°C, the colloid content of the heavy oil slurry is 10-40% by weight, and the asphaltene content of the heavy oil slurry is 5-20% by weight, so The solid content of the heavy oil slurry is 2-7g solid/L oil slurry.

Preferably, the weight ratio of the heavy oil slurry to the iron salt is 2-5:1.

Preferably, the carbonization temperature is 600-900° C., the carbonization pressure is 0.05-0.15 MPa, and the carbonization time is 10-120 min.

Preferably, the iron salt is at least one selected from ferric chloride, ferric hydroxide, ferric oxide, ferric nitrate, ferric sulfate and ferrocene.

Preferably, the temperature of the catalytic cracking is 600-1200° C., and the time of the catalytic cracking is 10-180 min.

Through the above technical solution, the method provided by the invention can make the non-ideal heavy components contained in the heavy oil slurry be utilized and transformed into carbon materials with higher value. Two-stage cracking technology is provided to make full use of non-ideal heavy components.

Description of drawings

Fig. 1 is the scanning electron micrograph of the porous carbon material obtained in the embodiment of the present invention 1;

Fig. 2 is the scanning electron micrograph of the cracked carbon that obtains in the embodiment of the present invention 1;

Fig. 3 is the scanning electron micrograph of the multilayer graphene that obtains in the embodiment of the present invention 2;

Fig. 4 is a scanning electron micrograph of carbon nanofibers obtained in Example 3 of the present invention.

Detailed ways

Neither the endpoints nor any values of the ranges disclosed herein are limited to such precise ranges or values, and these ranges or values are understood to include values approaching these ranges or values. For numerical ranges, between the endpoints of each range, between the endpoints of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, these values Ranges should be considered as specifically disclosed herein.

The invention provides a method for preparing carbon material from heavy oil slurry, comprising:

a. Under an inert atmosphere, carbonize the mixture of heavy oil slurry and iron salt to obtain cracked gas and porous carbon materials;

b. Condensing the cracked gas;

c. Catalytic cracking of the oil and gas components obtained by the condensation with a boiling point temperature below 50° C. to obtain carbon nanomaterials;

Wherein, the distillation range of the heavy oil slurry is >500°C, the colloid content of the heavy oil slurry is 10-40% by weight, and the asphaltene content of the heavy oil slurry is 5-20% by weight, so The solid content of the heavy oil slurry is 2-7g solid/L oil slurry.

The method provided by the invention processes the oil slurry obtained from the catalytic cracking process, and is used to prepare the heavy oil slurry containing non-ideal components separated in the process of needle coke, and uses the components therein as the source of carbon materials to convert Improve utilization of heavy oil slurry for higher value carbon materials. The above-mentioned method provided by the present invention provides two-stage cracking, first carbonization is carried out in step a to obtain a porous carbon material, and then the obtained cracked gas is further catalytically cracked to produce carbon nanomaterials. It can be observed by scanning electron microscope that the porous carbon material obtained in step a has a porous structure, as shown in FIG. 1 . The conditions in step a can achieve the porous carbon material.

In the step a of the method provided by the present invention, it is used to perform the first-stage cracking, and the heavy oil slurry is treated through the carbonization. Wherein, during the carbonization process, iron salt is also added to the heavy oil slurry for catalytic carbonization to obtain the porous carbon material. Preferably, the weight ratio of the heavy oil slurry to the iron salt is 2-5:1.

In the present invention, the iron salt may be a powder with an average particle size of 10-100 μm. Preferably, the iron salt is at least one selected from ferric chloride, ferric hydroxide, ferric oxide, ferric nitrate, ferric sulfate and ferrocene.

In step a of the method provided by the present invention, preferably, the carbonization temperature is 600-900° C., the carbonization pressure is 0.05-0.15 MPa, and the carbonization time is 10-120 min. This carbonization condition is conducive to the pyrolysis and carbonization of the heavy oil slurry with non-ideal components at high temperature, and further, catalytic carbonization with the participation of iron salts.

In the present invention, the inert atmosphere in step a may be a gas that does not affect or participate in the carbonization reaction process, and does not affect the performance of the obtained cracked gas and porous carbon material. For example, argon, nitrogen or a mixture of the two. The amount of the inert atmosphere introduced may be 100-500mL/min.

In the method provided by the present invention, preferably, in step a, the mixture is obtained by dissolving the heavy oil slurry in an organic solvent, mixing it with the iron salt, and then performing solvent distillation to remove the The organic solvent is used to obtain the mixture. The use of the organic solvent contributes to the uniform mixing of the heavy oil slurry and the iron salt. The organic solvent is removed by distillation to avoid interference with the carbonization reaction process and the impact on product cracked gas and porous carbon materials. Preferably, the organic solvent can be selected from nitrogen methylpyrrolidone (NMP) or toluene.

In the present invention, preferably, the weight ratio of heavy oil slurry: organic solvent: iron salt is 2-5:5-12:1.

In the present invention, in step a, the carbonization can be carried out in a heating furnace, and the components in the heavy oil slurry are thermally polycondensed and carbonized to form a porous carbon material. Preferably, the parameters of the porous carbon material include: an average pore diameter of 2-300 nm, and a specific surface area of 200-1600 m ² /g.

In the present invention, preferably, the method further includes cleaning the porous carbon material by contacting it with an acid solution, specifically including: mixing the porous carbon material with the acid solution, and then performing heating distillation to clean and remove the remaining metal salt compound . The acid solution is at least one of hydrochloric acid solution, nitric acid solution and sulfuric acid solution, and the mass concentration may be 10-30% by weight. The metal salt compound is mainly iron salt compound.

In step a of the present invention, the heavy oil slurry is transformed to provide the cracked gas, which can be suitable for further processing to produce carbon nanomaterials. Step b is used to further separate the components in the cracked gas. After the condensation, the cracked gas separates liquid components with a boiling point temperature greater than 50°C, which can be left in the condenser; and the separated liquid components with a boiling point temperature of 50°C The following oil and gas components can be further processed in step c. That is, the present invention selects the cracked gas obtained in step a, and selects oil and gas components whose boiling point temperature is below 50° C. to further prepare carbon nanomaterials.

Step c provided by the present invention is used to obtain carbon nanomaterials through the catalytic cracking reaction of the oil and gas components. Preferably, the temperature of the catalytic cracking is 600-1200° C., and the time of the catalytic cracking is 10-180 min.

In the method provided by the present invention, preferably, in step c, the catalyst for catalytic cracking comprises a carrier and a supported active component, and the active component is selected from the group consisting of copper, cobalt, iron, nickel, copper oxide, cobalt oxide, At least one of iron oxide, nickel oxide, copper salt, iron salt, cobalt salt, nickel salt, the carrier is MgO, Al ₂ O ₃ , Mg(OH) ₂ , Al(OH) ₃ and hydrotalcite at least one.

Further, as provided by some embodiments of the present invention, preferably, based on the total amount of the catalyst, the content of the active component is 0.5-2% by weight, and the content of the carrier is 98-99.5% by weight.

Furthermore, the method of the present invention can use different catalysts to obtain different carbon nanomaterials. Preferably, the carbon nanomaterial is cracked carbon, carbon nanofiber or graphene-like.

In the present invention, preferably, in step c, the amount relationship between the oil and gas component and the catalyst is 100-300mL oil and gas component/g catalyst. To make step c better realize the transformation of the oil and gas components into carbon nanomaterials.

The present invention will be described in detail below by way of examples. In the following examples,

The distillation range of the heavy oil slurry is >500°C, the colloid content is 28.7wt%, the asphaltene content is 17.6wt%, and the solid content is 2.3g solid/L oil slurry. Others: sulfur content 0.55wt%, ash content 0.63wt%, carbon residue (trace method) 26wt%, saturated hydrocarbon 15.5wt%, aromatic hydrocarbon 38.2wt%.

The pore size and specific surface area of the porous carbon materials were determined by the BET nitrogen adsorption method.

A scanning electron microscope (Hitachi SU8010, 3kV) was used to observe the morphology of the porous carbon material and various nano-carbon materials prepared in the examples.

Example 1

(1) The above-mentioned heavy oil slurry is dissolved in nitrogen methyl pyrrolidone (NMP), and then ferric chloride is added, heavy oil slurry: NMP: the mass ratio of ferric chloride is 2:10:1; after stirring, Carry out distillation solvent recovery NMP, obtain the solid mixture of heavy oil slurry and ferric chloride;

The mixture is put into a horizontal cracking furnace, fed with nitrogen as a protective gas, the flow rate is 200mL/min, and at a temperature of 900°C and a pressure of 0.15MPa, a heating carbonization reaction is carried out for 30min to obtain cracking gas and porous carbon material (average pore diameter about 200nm and a specific surface area of about 682m ² /g, the morphology observed by scanning electron microscope is shown in Figure 1); further, the prepared porous carbon material was washed with hydrochloric acid to wash away the remaining metal salts.

(2) The cracked gas produced in step (1) is condensed and separated into a liquid component with a boiling point greater than 50°C, and an oil and gas component with a boiling point below 50°C;

(3) Catalytic cracking reaction of oil and gas components and catalytic cracking catalyst (composition includes: 0.15 g of iron loaded on 10 g of hydrotalcite) at a temperature of 900 ° C for 60 minutes, the relationship between the amount of oil and gas components and the catalyst is 300 mL of oil and gas components /1g catalyst to produce pyrolysis carbon, the morphology observed by scanning electron microscope is shown in Figure 2.

Example 2

(1) above-mentioned heavy oil slurry is dissolved in toluene, then add ferric chloride, heavy oil slurry: NMP: the mass ratio of ferric chloride is 4:12:1; After stirring, carry out distillation solvent recovery toluene, Obtain a solid mixture in which the heavy oil slurry and ferric chloride are uniformly mixed;

The mixture is put into a horizontal cracking furnace, fed with nitrogen as a protective gas, the flow rate is 300mL/min, and at a temperature of 800°C and a pressure of 0.05MPa, a heating carbonization reaction is carried out for 30min to obtain cracking gas and porous carbon material (average pore diameter about 184nm, specific surface area about 902m ² /g, and the morphology is similar to that in Figure 1); further, the prepared porous carbon material was washed with hydrochloric acid to wash away the remaining metal salts.

(2) The cracked gas produced in step (1) is condensed and separated into a liquid component with a boiling point greater than 50°C, and an oil and gas component with a boiling point below 50°C;

(3) Catalytic cracking reaction of oil and gas components and catalytic cracking catalyst (composition includes: 0.2g of Cu loaded on 10g of hydrotalcite) at a temperature of 1200°C for 60min, the relationship between the amount of oil and gas components and catalyst is 100mL of oil and gas components /1g catalyst to produce multi-layer graphene-like, the morphology observed by scanning electron microscope is shown in Figure 3.

Example 3

(1) Dissolve the above-mentioned heavy oil slurry in nitrogen methyl pyrrolidone (NMP), then add ferric nitrate, the mass ratio of heavy oil slurry: NMP: ferric nitrate is 5:5:1; after stirring evenly, carry out distillation The solvent recovers NMP to obtain a solid mixture uniformly mixed with heavy oil slurry and ferric nitrate;

The mixture is put into a horizontal cracking furnace, fed with nitrogen as a protective gas, the flow rate is 200mL/min, and at a temperature of 900° C. and a pressure of 0.1 MPa, a heating carbonization reaction is carried out for 30 minutes to obtain cracked gas and a porous carbon material (average pore diameter is about 261nm, the specific surface area is about 843m ² /g, and the morphology is shown in Figure 1); further, the prepared porous carbon material is washed with hydrochloric acid to wash away the remaining metal salts.

(2) The cracked gas produced in step (1) is condensed and separated into a liquid component with a boiling point greater than 50°C, and an oil and gas component with a boiling point below 50°C;

(3) Catalytic cracking reaction of oil and gas components and catalytic cracking catalyst (composition includes: 0.06g of Co loaded on 10g of hydrotalcite) at a temperature of 600°C for 60min, and the relationship between oil and gas components and catalyst is 100mL of oil and gas components /1g catalyst to produce carbon nanofibers, the morphology observed by scanning electron microscope is shown in Figure 4.

It can be seen from the examples that by using the examples of the method provided by the present invention, the non-ideal components in the heavy oil slurry can be utilized to prepare various carbon nanomaterials.

The preferred embodiments of the present invention have been described in detail above, however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the disclosed content of the present invention. All belong to the protection scope of the present invention.

Claims (10)

1. A method for preparing carbon material from heavy oil slurry comprises the following steps:

a. carbonizing a mixture of heavy oil slurry and ferric salt in an inert atmosphere to obtain pyrolysis gas and a porous carbon material;

b. condensing the cracked gas;

c. carrying out catalytic cracking on the oil gas component with the boiling point temperature of below 50 ℃ obtained by condensation to obtain a carbon nano material;

wherein the distillation range of the heavy oil slurry is more than 500 ℃, the colloid content of the heavy oil slurry is 10-40 wt%, the asphaltene content of the heavy oil slurry is 5-20 wt%, and the solid content of the heavy oil slurry is 2-7g solid/L oil slurry;

in the step a, the carbonization temperature is 600-900 ℃, the carbonization pressure is 0.05-0.15MPa, and the carbonization time is 10-120min;

in step c, the carbon nanomaterial is cracked carbon, carbon nanofiber or graphene-like.

2. The method according to claim 1, wherein in step a, the weight ratio of the heavy oil slurry to the iron salt is 2-5:1.

3. the method of claim 1, wherein in step a, the mixture is obtained by: and dissolving the heavy oil slurry in an organic solvent, uniformly mixing the heavy oil slurry with the ferric salt, and then distilling the solvent to remove the organic solvent to obtain the mixture.

4. The method of claim 3, wherein the heavy slurry: organic solvent: the weight ratio of the ferric salt is 2-5:5-12:1.

5. the method of any one of claims 1-4, wherein the iron salt is selected from at least one of iron trichloride, iron nitrate, iron sulfate, and ferrocene.

6. The method of claim 1 further comprising contacting the porous carbon material with an acid solution to clean and remove residual metal salt compounds.

7. The method of claim 1, wherein the temperature of the catalytic cracking in the step c is 600-1200 ℃, and the time of the catalytic cracking is 10-180min.

8. The method of claim 1, wherein in step c, the catalytic cracking catalyst comprises a carrier and a supported active component, the active component is selected from at least one of copper, cobalt, iron, nickel, copper oxide, cobalt oxide, iron oxide, nickel oxide, copper salt, iron salt, cobalt salt and nickel salt, and the carrier is MgO, al ₂ O ₃ 、Mg(OH) ₂ 、Al(OH) ₃ And hydrotalcite.

9. The method according to claim 8, wherein the active component is contained in an amount of 0.5-2 wt% and the carrier is contained in an amount of 98-99.5 wt%, based on the total amount of the catalyst.

10. The method of claim 8 or 9, wherein in step c, the amount of hydrocarbon component and catalyst is in the range of 100-300mL of hydrocarbon component per g of catalyst.

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