CN109135818B

CN109135818B - Preparation method and production equipment of petroleum coke

Info

Publication number: CN109135818B
Application number: CN201811176272.1A
Authority: CN
Inventors: 于珊珊; 崔新安; 王洪彬
Original assignee: Sinopec Engineering Group Co Ltd; Sinopec Luoyang Technology Co Ltd
Current assignee: Sinopec Engineering Group Co Ltd; Sinopec Luoyang Technology Co Ltd
Priority date: 2018-10-09
Filing date: 2018-10-09
Publication date: 2021-08-31
Anticipated expiration: 2038-10-09
Also published as: CN109135818A

Abstract

The invention provides a residual oil desulfurization method, a preparation method of petroleum coke and production equipment, and relates to the technical field of petroleum coking, wherein the residual oil desulfurization method comprises the following steps: s1) providing residual oil as a reaction raw material, and mixing the residual oil with a pretreatment agent to pretreat the residual oil; wherein the pre-treatment agent comprises a metal base and/or a metal carbonate; s2) placing the pretreatment mixture obtained in the step S1) in an electrostatic field for electrostatic adsorption desulfurization treatment to complete the desulfurization of the residual oil, and obtaining the residual oil with low sulfur content. The residual oil desulfurization method can relieve the technical problems of high process difficulty, high cost and poor desulfurization effect in the prior art when petroleum coke is desulfurized, and achieves the purposes of reducing the desulfurization difficulty and improving the desulfurization effect by desulfurizing the raw materials.

Description

Preparation method and production equipment of petroleum coke

Technical Field

The invention relates to the technical field of petroleum coking, in particular to a residual oil desulfurization method, a preparation method of petroleum coke and production equipment.

Background

Petroleum coke is a coke produced by delayed coking of residual oils. At present, most of petroleum coke products in China are high-sulfur petroleum coke (the sulfur content is higher than 3%). The use of high-sulfur petroleum coke not only causes the corrosion of equipment and the increase of production cost of enterprises, but also causes serious pollution to the environment. With the attention of the country to environmental protection in recent years, the environmental protection grade is gradually upgraded, and the demand of high-quality low-sulfur petroleum coke is increased in the future, so that the sulfur content in the petroleum coke is inevitably reduced.

Currently, in order to obtain low-sulfur petroleum coke, methods such as high-temperature calcination, wet chemical oxidation, medium gas desulfurization, solvent extraction and the like are mainly adopted to perform desulfurization treatment on the high-sulfur petroleum coke. The high-temperature calcination method is to calcine petroleum coke at 1600 ℃ and has the desulfurization rate of over 50 percent but large energy consumption. The wet chemical oxidation method is a method of adopting chemical reagent oxidation to convert organic sulfur which is insoluble in water in petroleum coke into inorganic sulfur which is soluble in water or acid so as to achieve the aim of desulfurization, but the method can generate a large amount of waste water. The medium gas desulfurization refers to that the petroleum coke is placed in a desulfurization medium gas for a period of constant temperature, so that sulfur in the petroleum coke and the medium gas interact to achieve the aim of desulfurization, but the method has high energy consumption and great danger. The solvent extraction method is to extract sulfur in petroleum coke into a solvent by adopting an organic solvent extraction method so as to achieve the aim of desulfurization, but the method has low desulfurization rate, and most of organic solvents are toxic, flammable and explosive, and have higher cost. From the analysis, the petroleum coke is used as the raw material, and the desulfurization is directly carried out on the petroleum coke, so that the difficulty is high, the cost is high, and the effect is limited.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The core of the invention is to find that the sulfur content in petroleum coke mainly depends on the sulfur content and sulfur form in the raw material for producing petroleum coke, namely residual oil, the sulfur form in the residual oil is changed into sulfide which is easy to remove, and the sulfide is removed in advance before coking reaction, so that the petroleum coke with low sulfur content can be obtained. Meanwhile, the inventor of the invention also finds that the existence form of sulfur in the residual oil can be changed into easily removed sulfide by using the metal alkali or the metal carbonate.

It is a first object of the present invention to provide a desulfurization method to alleviate at least one of the above problems.

The second objective of the present invention is to provide a method for preparing petroleum coke, so as to alleviate the technical problems of the prior art, such as difficulty in directly desulfurizing petroleum coke, high cost and poor desulfurization effect.

The third purpose of the invention is to provide petroleum coke production equipment, and the low-sulfur petroleum coke can be obtained by using the production equipment to produce the petroleum coke.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

a process for the desulfurization of residuum comprising the steps of:

s1) providing residual oil as a reaction raw material, and mixing the residual oil with a pretreatment agent to pretreat the residual oil; wherein the content of the first and second substances,

the pretreatment agent comprises a metal base and/or a metal carbonate;

s2) placing the pretreatment mixture obtained in the step S1) in an electrostatic field for electrostatic adsorption desulfurization treatment to complete the desulfurization of the residual oil, and obtaining the residual oil with low sulfur content.

Further, the metal base comprises sodium hydroxide, potassium hydroxide and/or calcium hydroxide;

the metal carbonate comprises sodium carbonate and/or potassium carbonate.

Furthermore, in the mixture of the residual oil and the pretreating agent, the mass fraction of the pretreating agent is 0.5-20%, preferably 1-10%, and more preferably 1-5%.

Further, the reaction temperature of the pretreatment in the step S1) is 50-350 ℃, preferably 100-300 ℃, and more preferably 150-250 ℃; the reaction time is 0.1 to 5 hours, preferably 0.5 to 2 hours, and more preferably 0.5 to 1.5 hours.

Further, in the step S2), the temperature of the mixture to be pretreated is 50 to 300 ℃, preferably 100 to 250 ℃, and more preferably 100 to 150 ℃.

Further, in step S2), the electric field intensity of the electrostatic field is 500 to 15000V/cm, preferably 1500 to 10000V/cm, and more preferably 2000 to 5000V/cm.

Further, the electrostatic field is an alternating current electric field, a direct current electric field or an alternating current-direct current alternating electric field, and is preferably a direct current electric field.

A preparation method of petroleum coke comprises the following steps:

the desulfurized residual oil obtained according to the residual oil desulfurization method is coked to obtain petroleum coke.

Further, the coking reaction temperature in the coking treatment is 450-550 ℃, preferably 450-500 ℃, and further preferably 460-500 ℃; the coking reaction time is 0.5-8 h, preferably 2-6 h, and more preferably 3-5 h.

The production equipment for realizing the petroleum coke comprises a pretreatment tank, an electrostatic treatment tank and a coke tower which are sequentially communicated.

Compared with the prior art, the invention has the following beneficial effects:

in the research of the invention, the residual oil can react with metal alkali or metal carbonate, thereby changing the form of sulfur-containing compounds in the residual oil. In the residual oil desulfurization method provided by the invention, metal alkali or metal carbonate is used as a pretreatment agent to pretreat residual oil so as to change the existence form of sulfur in the residual oil; then the sulfur-containing compounds are separated out through the coalescence, adsorption and sedimentation characteristics of the electrostatic field, and the desulfurization of the residual oil is realized, so that the residual oil with low sulfur content is obtained.

The preparation method of the petroleum coke provided by the invention starts from the raw material of the petroleum coke, the adopted raw material residual oil is the residual oil with low sulfur content which is subjected to pretreatment and electrostatic coalescence adsorption and then is subjected to sulfur compound removal, and the petroleum coke with low sulfur content is prepared by adopting the residual oil with low sulfur content, thereby providing a new thought for the preparation of the petroleum coke with low sulfur content. Compared with the traditional retreatment desulfurization of high-sulfur petroleum coke, the preparation method has the advantages of obviously reduced energy consumption, simple process, easy operation, realization of continuous production and obvious economic benefit.

The petroleum coke production equipment provided by the invention comprises a pretreatment tank, an electrostatic treatment tank and a coke tower which are sequentially communicated. In the production process, firstly, the residual oil and the pretreating agent are placed in a pretreatment tank for mixing reaction to change the form of the sulfur-containing compound in the residual oil, then the pretreated residual oil passes through an electrostatic treatment tank, the sulfur-containing compound in the residual oil is separated out through the coalescence, adsorption and sedimentation characteristics of an electrostatic field to realize the desulfurization of the residual oil, and finally the desulfurized residual oil is introduced into a coke tower for coking reaction to obtain the low-sulfur petroleum coke. The continuous production of the low-sulfur petroleum coke can be directly realized through the production equipment, and the production efficiency is high.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a petroleum coke production facility according to the present invention;

fig. 2 is a flow chart of a process for preparing petroleum coke according to an embodiment of the present invention.

Icon: 10-a pretreatment tank; 20-an electrostatic treatment tank; 30-coke drum.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

A process for the desulfurization of residuum comprising the steps of:

the pretreatment agent comprises a metal base and/or a metal carbonate;

The sulfur-containing compounds in the residual oil, such as mercaptan or thioether, and the pretreating agent are subjected to chemical reaction to generate oil-insoluble sulfur-containing compounds, and under the action of an electric field, the sulfur-containing compounds are subjected to agglomeration and adsorption to realize residual oil sulfur removal.

In some embodiments of the invention, the metal base comprises sodium hydroxide, potassium hydroxide, and/or calcium hydroxide; the metal carbonate comprises sodium carbonate and/or potassium carbonate.

Tests prove that when the metal alkali is sodium hydroxide, potassium hydroxide and/or calcium hydroxide, or when the metal carbonate is sodium carbonate and/or carbonic acid, the desulfurization effect is better.

In the above embodiments, the metal base includes a hydroxide of a metal and a mixture of metal bases, and the metal base may be, for example, sodium hydroxide, potassium hydroxide, calcium hydroxide, a combination of sodium hydroxide and potassium hydroxide, and a combination of sodium hydroxide and calcium hydroxide. The metal carbonate may be, for example, sodium carbonate, potassium carbonate or a mixture of sodium carbonate and potassium carbonate.

In some embodiments of the present invention, the mass fraction of the pretreating agent in the mixture of the residual oil and the pretreating agent is 0.5% to 20%, in further preferred embodiments 1% to 10%, and in still further preferred embodiments 1% to 5%.

The addition amount of the pretreating agent is increased, and the desulfurization effect is improved. However, when the addition amount of the pretreating agent is increased to a certain extent, the addition amount is increased, the increase degree of the desulfurization rate is limited, and the pretreating agent is wasted; and if the addition amount of the pretreating agent is too small, the desulfurization effect of the residual oil is affected.

By limiting the using amount of the pretreating agent, the pretreatment agent is prevented from being too much, the subsequent electrostatic separation and coking treatment in the petroleum coke production process are influenced, the desulfurization can be effectively carried out, and the desulfurization effect of the residual oil is improved.

In the above embodiment, in the mixture of the residual oil and the pretreating agent, the mass fraction of the pretreating agent may be, for example, 0.5%, 1%, 2%, 3%, 5%, 7%, 8%, 10%, 12%, 15%, 17%, or 20%.

In some embodiments of the present invention, during the pretreatment, the reaction temperature of the pretreatment is 50 to 350 ℃, and the reaction time is 0.1 to 5 hours; in a further preferred embodiment of the invention, the reaction temperature of the pretreatment is 100-300 ℃, and the reaction time is 0.5-2 h; in a further preferred embodiment of the present invention, the reaction temperature of the pretreatment is 150 to 250 ℃ and the reaction time is 0.5 to 1.5 hours.

By limiting the reaction temperature of pretreatment, coking of residual oil can be effectively prevented, and the reaction of the residual oil and the pretreatment agent is fully carried out, so that desulfurization is realized.

In some embodiments of the present invention, the temperature of the pre-treatment mixture in the step S2) is 50 to 300 ℃, in further preferred embodiments of the present invention the temperature of the pre-treatment mixture is 100 to 250 ℃, and in further preferred embodiments of the present invention the temperature of the pre-treatment mixture is 100 to 150 ℃.

On one hand, the coking tendency of the residual oil with overhigh temperature is increased, and once the residual oil generates coke, the current in the electric dehydration process is increased; on the other hand, even if the residual oil is not coked and the temperature is too high, the current in the electrostatic adsorption desulfurization process is increased. Therefore, the temperature is required to be controlled within a reasonable range in the electric dehydration process, and the stable operation of the electric dehydration tank is ensured.

And controlling the temperature of the pretreated mixture obtained after the pretreatment reaction at 50-300 ℃, then performing electrostatic adsorption, and heating or cooling the temperature of the pretreated mixture in a heat exchange manner.

In some embodiments of the present invention, in step S2), the electrostatic field has an electric field strength of 500 to 15000V/cm, in a further preferred embodiment of the present invention, the electrostatic field has an electric field strength of 1500 to 10000V/cm, and in a further preferred embodiment of the present invention, the electrostatic field has an electric field strength of 2000 to 5000V/cm.

In the electrostatic treatment process, the electric field intensity needs to be controlled in a reasonable range, and the phenomenon of frequent tripping caused by overlarge current of electrostatic equipment due to overhigh electric field intensity causes that the electrostatic equipment cannot run stably; however, the electric field is too low, the sulfur-containing compounds cannot be rapidly agglomerated and adsorbed, and the removal effect of the sulfur-containing compounds is influenced.

In some embodiments of the present invention, the electrostatic field is an alternating current electric field, a direct current electric field, or an alternating current-alternating current electric field, preferably a direct current electric field.

In another aspect, the present invention provides a method for preparing petroleum coke, comprising the steps of:

In some embodiments of the present invention, the coking reaction temperature in the coking treatment is 450 to 550 ℃, preferably 450 to 500 ℃, and more preferably 460 to 500 ℃; the coking reaction time is 0.5-8 h, preferably 2-6 h, and more preferably 3-5 h.

In another aspect, the invention provides a production device for realizing the petroleum coke, which comprises a pretreatment tank, an electrostatic treatment tank and a coke tower which are sequentially communicated.

The petroleum coke production equipment provided by the invention comprises a pretreatment tank 10, an electrostatic treatment tank 20 and a coke tower 30 which are sequentially communicated as shown in figure 1. In the production process, firstly, the residual oil and the pretreating agent are placed in a pretreatment tank 10 for mixing reaction to change the form of the sulfur-containing compound in the residual oil, and then the pretreated residual oil passes through an electrostatic treatment tank 20 to separate the sulfur-containing compound in the residual oil through the coalescence, adsorption and sedimentation characteristics of an electrostatic field, so that the desulfurization of the residual oil is realized; and finally, introducing the desulfurized residual oil into a coke tower 30 for coking reaction, discharging an oil gas product generated by the coking reaction from the upper part of the coke tower 30, and discharging the generated coke from the bottom of the coke tower 30 to obtain the low-sulfur petroleum coke. The continuous production of the low-sulfur petroleum coke can be directly realized through the production equipment, and the production efficiency is high.

The present invention will be described in further detail with reference to examples and comparative examples.

Example 1

The embodiment is a preparation method of petroleum coke, and the process flow chart is shown in fig. 2, and comprises the following steps:

s1) preprocessing: mixing residual oil and sodium hydroxide in a pretreatment tank according to a mass ratio of 90:10 for reaction, wherein the reaction temperature is 350 ℃, and the reaction time is 1.5 h;

s2) electrostatic adsorption: after the residual oil after the pretreatment reaction is subjected to heat exchange and is cooled to 300 ℃, the residual oil enters an electrostatic treatment tank with direct current electric field intensity of 5000V/cm for desulfurization treatment;

s3) coking reaction: and (3) heating the desulfurized residual oil to 490 ℃ through heat exchange, then feeding the residual oil into a coke tower for coking reaction for 4h, and obtaining the petroleum coke with low sulfur content after the reaction is finished.

Example 2

The embodiment is a preparation method of petroleum coke, which comprises the following steps:

s1) preprocessing: mixing residual oil and sodium hydroxide in a pretreatment tank according to a mass ratio of 99:1 for reaction at 350 ℃ for 1.5 h;

s2) electrostatic adsorption: after heat exchange, residual oil after the pretreatment reaction is carried out to 150 ℃, and then enters an electrostatic treatment tank with the direct current electric field intensity of 1500V/cm for desulfurization treatment;

Example 3

s1) preprocessing: mixing residual oil and sodium hydroxide in a pretreatment tank according to a mass ratio of 95:5 for reaction at 350 ℃ for 1.5 h;

s2) electrostatic adsorption: after heat exchange, residual oil after the pretreatment reaction is carried out to 300 ℃, and then enters an electrostatic treatment tank with direct current electric field intensity of 5000V/cm for desulfurization treatment;

Example 4

s1) preprocessing: mixing residual oil and sodium hydroxide in a pretreatment tank according to a mass ratio of 95:5, and reacting at 250 ℃ for 2 hours;

Example 5

s1) preprocessing: mixing residual oil and potassium hydroxide in a pretreatment tank according to a mass ratio of 99:1 for reaction at 300 ℃ for 1 h;

s2) electrostatic adsorption: the residual oil after the pretreatment reaction is subjected to heat exchange to 200 ℃, and then enters an electrostatic treatment tank with the direct-current electric field intensity of 3000V/cm for desulfurization treatment;

Example 6

s1) preprocessing: mixing residual oil and potassium hydroxide in a pretreatment tank according to a mass ratio of 95:5, and reacting at 250 ℃ for 2 hours;

Example 7

s1) preprocessing: mixing residual oil and sodium carbonate in a mass ratio of 85:15 in a pretreatment tank for reaction at the temperature of 350 ℃ for 1.5 h;

Example 8

s1) preprocessing: mixing residual oil and sodium carbonate in a mass ratio of 95:5 in a pretreatment tank for reaction at the temperature of 300 ℃ for 1 h;

Example 9

s1) preprocessing: mixing residual oil and sodium carbonate in a mass ratio of 95:5 in a pretreatment tank for reaction at the temperature of 350 ℃ for 1.5 h;

Example 10

s2) electrostatic adsorption: after heat exchange, residual oil after the pretreatment reaction is carried out to 250 ℃, and then enters an electrostatic treatment tank with direct current electric field intensity of 3000V/cm for desulfurization treatment;

Example 11

s1) preprocessing: mixing residual oil and potassium carbonate in a pretreatment tank according to a mass ratio of 99:1 for reaction at 300 ℃ for 1 h;

Example 12

s1) preprocessing: mixing residual oil and potassium carbonate in a mass ratio of 95:5 in a pretreatment tank for reaction at 250 ℃ for 2 hours;

Comparative example 1

The comparative example is a preparation method of petroleum coke, in the preparation method, residual oil is directly heated to 490 ℃ and then introduced into a coke tower to react for 4 hours, so that the petroleum coke is obtained.

Comparative example 2

The comparative example is a preparation method of petroleum coke, comprising the following steps:

s1) heating the residual oil to 300 ℃, and then introducing the residual oil into an electrostatic treatment tank with an alternating current electric field strength of 1500V/cm for desulfurization treatment;

s2), heating the residual oil after electrostatic treatment to 490 ℃, and introducing into a coke tower for reaction for 4 hours to obtain petroleum coke.

Comparative example 3

s1) heating the residual oil to 200 ℃, and introducing the residual oil into an electrostatic treatment tank with direct-current electric field intensity of 5000V/cm for desulfurization treatment;

Comparative example 4

S1) heating the residual oil to 150 ℃, and then introducing into an electrostatic treatment tank with the alternating current electric field strength of 15000V/cm for desulfurization treatment;

It is shown that the amount of lithium contained in the reaction raw material residue used in examples 1 to 12 and comparative examples 1 to 4 is the same.

The petroleum cokes of examples 1-12 and comparative examples 1-4 were tested for sulfur content, respectively, and the results are shown in table 1.

TABLE 1 test results

It can be seen from the data in table 1 that when the same pretreatment agent is used, the desulfurization effect is affected by changing the ratio of the residue to the pretreatment agent, or changing the pretreatment temperature and time, or changing the temperature and the intensity of the electrostatic field during the electrostatic adsorption process. When the conditions are matched with each other to achieve a better state, the sulfur content in the finally obtained petroleum coke can be reduced to 0.3 percent.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The preparation method of the petroleum coke is characterized by comprising the following steps:

s1) preprocessing: mixing residual oil and sodium hydroxide in a pretreatment tank according to a mass ratio of 90:10 for reaction, wherein the reaction temperature is 350 ℃, and the reaction time is 1.5 h; the sulfur-containing compounds in the residual oil include mercaptans or sulfides;

2. The petroleum coke production equipment for realizing the preparation method of claim 1 is characterized by comprising a pretreatment tank, an electrostatic treatment tank and a coke tower which are communicated in sequence.