CN112742476B

CN112742476B - Catalyst, preparation method thereof and method for producing low-sulfur petroleum coke

Info

Publication number: CN112742476B
Application number: CN201911040138.3A
Authority: CN
Inventors: 李子锋; 任磊; 李集亮; 肖荣军; 王勇
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2023-09-05
Anticipated expiration: 2039-10-29
Also published as: CN112742476A

Abstract

The present disclosure relates to a catalyst for reducing sulfur content in petroleum coke, the catalyst comprising an oil-soluble organo-molybdenum compound, an anion of the oil-soluble organo-molybdenum compound comprising a first organic acid radical and a second organic acid radical; the first organic acid radical is a C1-C6 oxygen-containing organic acid radical, and the second organic acid radical is a C7-C16 oxygen-containing organic acid radical; the acid value of the catalyst is 300-450mg KOH/kg. The catalyst disclosed by the invention has high catalytic efficiency, good oil solubility and proper acid value distribution, and high selectivity for sulfur oxidation in residual oil oxidative desulfurization.

Description

Catalyst, preparation method thereof and method for producing low-sulfur petroleum coke

Technical Field

The present disclosure relates to a catalyst, a method of preparing the same, and a method of producing low sulfur petroleum coke.

Background

With the rapid development of global economy, the demand for energy is increasing, and the degree of heavy and poor quality of petroleum resources is increasing after long-term development. The poor quality, heavy quality and environmental protection requirements of petroleum resources are increasingly strict, new challenges are presented to the oil refining technology, and the efficient green conversion of heavy oil is required to 'eat and clean' raw oil as much as possible on one hand, and on the other hand, environmental protection is required.

At present, under the condition that the sulfur content in crude oil is higher and the environmental protection requirement is stricter, the sulfur content in petroleum coke produced by delayed coking cannot be more than 3%, so that the high-sulfur petroleum coke is in the condition of being unable to leave factories. The use of hydrogenation processes to remove sulfur from residuum is difficult and equipment investment and hydrogen consumption would be a challenge for a refinery. Therefore, under the background, the exploration and development of the non-hydrogenated residual oil deep desulfurization technology to reach the low-sulfur or non-sulfur petroleum coke standard has important practical significance.

The oxidative desulfurization technology is a non-hydrodesulfurization technology which is widely focused in recent years, can be performed at normal temperature and normal pressure, has low equipment investment, is easier to oxidatively desulfurize due to the fact that the substituent dibenzothiophene compound has higher sulfur atom electron cloud density, and is widely researched and applied to the desulfurization of gasoline, diesel oil and fuel oil at present. The principle of the oxidative desulfurization technology is that sulfur in thiophene and derivatives thereof is oxidized into corresponding sulfoxide or sulfone with large polarity by using a catalyst and an oxidant, and then the sulfone is separated out by using the property difference between the sulfone and hydrocarbon materials through methods such as rectification, solvent extraction or adsorption, so as to achieve the purpose of desulfurization. However, for residuum, it is not suitable to use a solid catalyst and also to separate the sulfur component using rectification, solvent extraction, or adsorption, etc.

Disclosure of Invention

The catalyst disclosed by the disclosure has good oil solubility and acid value, and has a good auxiliary catalytic effect on oxidative desulfurization of residual oil.

To achieve the above object, a first aspect of the present disclosure provides a catalyst for reducing sulfur content in petroleum coke, the catalyst containing an oil-soluble organomolybdenum compound whose anion includes a first organic acid radical and a second organic acid radical; the first organic acid radical is a C1-C6 oxygen-containing organic acid radical, and the second organic acid radical is a C7-C16 oxygen-containing organic acid radical; the acid value of the catalyst is 300-450mg KOH/kg.

Optionally, the molar ratio of the first organic acid radical to the second organic acid radical is (0.1-0.3): 1, preferably (0.15-0.2): 1.

optionally, the content of molybdenum element in the organic molybdenum compound is 12-18 wt%.

Alternatively, the catalyst has an acid number of 380-440mg KOH/kg.

Optionally, the first organic acid radical is a monocarboxylate, a dicarboxylic acid radical or a polycarboxylic acid radical of C1-C6; the second organic acid radical is monocarboxylate, dicarboxylic acid radical or polycarboxylic acid radical of C7-C16.

Optionally, the first organic acid radical is selected from one or more of formic acid, acetate radical, oxalate radical, propionate radical and valerate radical;

the second organic acid radical is selected from one or more of heptanoic acid radical, 2-propylheptanoic acid radical, octanoic acid radical, isooctanoic acid radical, 2-ethylhexyl acid radical, nonanoic acid radical, 2-phenylpropionic acid radical, phenylacetic acid radical, phthalic acid radical, isophthalic acid radical, terephthalic acid radical, suberic acid radical and pimelic acid radical.

A second aspect of the present disclosure provides a method of preparing a catalyst for reducing sulfur content in petroleum coke, the method comprising:

(1) Enabling a molybdenum source, a solvent and a first organic acid to react for 0.5-4 hours at the temperature of 40-150 ℃ to obtain a first product; the molar ratio of the molybdenum source to the amount of the first organic acid calculated as molybdenum element is 1: (1-8);

(2) Reacting the first product with a second organic acid at 150-300 ℃ for 2-10 hours and removing the solvent from the resulting second product; the molar ratio of the molybdenum source to the amount of the second organic acid calculated as molybdenum element is 1: (1-15);

wherein the first organic acid is a C1-C6 oxygen-containing organic acid, and the second organic acid is a C7-C16 oxygen-containing organic acid.

Optionally, the second reaction product is an oil phase.

Optionally, in step (1), the molar ratio of the molybdenum source to the amount of the first organic acid calculated as molybdenum element is 1: (2-5);

in the step (2), the molar ratio of the molybdenum source to the second organic acid used in terms of molybdenum element is 1: (2-8).

Optionally, step (2) includes: and (3) dropwise adding a second organic acid into the first product within 5-60min at 150-300 ℃, continuing to react for 3-6h after the dropwise adding is finished, and removing the solvent through reduced pressure distillation after the reaction is finished.

Optionally, the solvent is selected from water and/or an organic solvent; the organic solvent is selected from benzene, toluene, ethanol or petroleum ether; the weight ratio of the water to the organic solvent is 1: (0-1);

the weight ratio of the molybdenum source to the solvent is 1: (5-30).

Optionally, the molybdenum source is selected from one or more of molybdenum trioxide, ammonium molybdate and ammonium paramolybdate.

Optionally, in the step (1), the first organic acid is one or more of formic acid, acetic acid, oxalic acid, propionic acid and valeric acid;

in the step (2), the second organic acid is one or more of heptanoic acid, 2-propyl heptanoic acid, octanoic acid, isooctanoic acid, 2-ethylhexanoic acid, nonanoic acid, 2-phenylpropionic acid, phenylacetic acid, phthalic acid, isophthalic acid, terephthalic acid, suberic acid and pimelic acid.

A third aspect of the present disclosure provides a catalyst for reducing sulfur content in petroleum coke prepared by the method provided in the second aspect of the present disclosure.

A fourth aspect of the present disclosure provides a method of producing low sulfur petroleum coke, the method comprising:

(1) Mixing residual oil, a diluting solvent, an oxidant and a catalyst to perform oxidation desulfurization reaction to obtain a mixture containing desulfurized residual oil, and removing the diluting solvent in the mixture to obtain desulfurized residual oil;

(2) Introducing the desulfurized residual oil into a delayed coking reaction device for delayed coking to obtain a low-sulfur petroleum coke product and sulfur-containing cracked gas;

wherein the catalyst is a catalyst for reducing sulfur content in petroleum coke provided in the first aspect of the present disclosure or provided in the third aspect of the present disclosure.

Optionally, in step (1), the residual oil, the diluting solvent and the catalyst are used in a weight ratio of 1: (0.5-2.5): (0.02-0.05).

Optionally, the oxidizing agent is hydrogen peroxide, and the molar ratio of the hydrogen peroxide to sulfur in the residual oil is (1-10): 1.

optionally, in step (1), the operating conditions of the oxidative desulfurization reaction are: the reaction temperature is 70-90 ℃ and the reaction time is 0.7-1.5h;

in step (2), removing the diluent solvent from the reacted residuum comprises: feeding the reacted residual oil into an atmospheric distillation tower or a vacuum distillation tower for distillation, wherein the temperature of the top of the tower is 70-350 ℃, the temperature of the bottom of the tower is 200-350 ℃, obtaining a mixture of a diluting solvent and water from the top of the tower, cooling and separating the mixture at 100-50 ℃, and returning the separated diluting solvent to the step (1) for recycling;

the conditions of the delayed coking are as follows: the outlet temperature of the delayed coking heating furnace is 490-500 ℃, the pressure is 0.1-0.25MPa, and the circulation ratio is 0-0.4.

Through above-mentioned technical scheme, the catalyst of this disclosure has following advantage:

(1) The catalyst has the advantages of small dosage, high catalytic efficiency and high selection of sulfur oxidation, the catalyst does not need to be separated after the reaction, and the sulfur content in petroleum coke can be reduced by more than 50 percent;

(2) The catalyst disclosed by the invention contains two organic oxygen acid radicals, has good compatibility with residual oil, has proper acid value distribution, and has a good auxiliary catalytic effect on residual oil oxidative desulfurization.

The method disclosed by the invention is clean and environment-friendly.

Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification, illustrate the disclosure and together with the description serve to explain, but do not limit the disclosure. In the drawings:

FIG. 1 is an infrared spectrum of an organomolybdenum compound prepared in example 1 of the present disclosure;

FIG. 2 is an infrared spectrum of an organomolybdenum compound prepared in example 2 of the present disclosure;

FIG. 3 is an infrared spectrum of molybdenum isooctanoate.

Detailed Description

Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.

A first aspect of the present disclosure provides a catalyst for reducing sulfur content in petroleum coke, the catalyst comprising an oil-soluble organomolybdenum compound, an anion of the oil-soluble organomolybdenum compound comprising a first organic acid radical and a second organic acid radical; the first organic acid radical is C1-C6 oxygen-containing organic acid radical, and the second organic acid radical is C7-C16 oxygen-containing organic acid radical; the acid value of the catalyst is 300-450mg KOH/kg.

The catalyst disclosed by the invention contains two specific types of organic anions and excessive organic acid, has higher catalytic efficiency, good oil solubility and proper acid value distribution, is especially suitable for the oxidative desulfurization process of residual oil, has better auxiliary catalytic effect on the oxidative desulfurization of residual oil, has high sulfur oxidation selectivity, and can reduce the sulfur content in petroleum coke by at least 50%.

According to the present disclosure, the molar ratio of the first organic acid radical to the second organic acid radical may vary within a wide range, preferably (0.1-0.3): 1, more preferably (0.15 to 0.2): 1.

according to the present disclosure, the content of molybdenum element in the organomolybdenum compound may be 12 to 18% by weight, preferably 14 to 16% by weight.

In accordance with the present disclosure, the catalyst of the present disclosure contains an excess of organic acid, and the acid value of the catalyst may be 380-440mg KOH/kg. The catalyst has better acid value distribution in the range, and can further improve the stability, the catalytic efficiency and the selectivity of sulfur oxidation.

According to the present disclosure, in the organomolybdenum compound, the C1-C6 oxygen-containing organic acid radical means an anion or an atomic group obtained after the oxygen-containing organic acid having 1 to 6 carbon atoms loses hydrogen. For example, the C1-C6 oxygen-containing organic acid radical may be a formate radical derived from the loss of hydrogen from formic acid, an acetate radical derived from the loss of hydrogen from acetic acid, or a propionate radical derived from the loss of hydrogen from propionic acid. The C1-C6 oxygen-containing organic acid radical can be a monocarboxylate, a dicarboxylic acid radical or a polycarboxylic acid radical with the carbon number of 1-6. In a preferred embodiment, the first organic acid radical may be one or more of formate, acetate, oxalate, propionate and valerate.

According to the present disclosure, in the organomolybdenum compound, the C7-C16 oxygen-containing organic acid radical means an anion or an atomic group obtained after the oxygen-containing organic acid having 7 to 16 carbon atoms loses hydrogen. For example, the C7-C16 oxygen-containing organic acid radical may be 2-propylheptanoic acid radical obtained by losing hydrogen from 2-propylheptanoic acid, 2-ethylhexanoic acid radical obtained by losing hydrogen from 2-ethylhexanoic acid, octanoic acid radical obtained by losing hydrogen from octanoic acid, heptanoic acid radical obtained by losing hydrogen from heptanoic acid. The C7-C16 oxygen-containing organic acid radical can be a monocarboxylate, a dicarboxylic acid radical or a polycarboxylic acid radical with 7-16 carbon atoms. In a preferred embodiment, the second organic acid radical may be one or more of heptanoate, 2-propylheptanoate, octanoate, isooctanoate, 2-ethylhexanoate, nonanoate, 2-phenylpropionate, phenylacetate, phthalate, isophthalate, terephthalate, suberate and pimelate.

wherein the first organic acid is a C1-C6 oxygen-containing organic acid, and the second organic acid is a C7-C16 oxygen-containing organic acid. In one embodiment, in step (2), the reaction time is 3 to 6 hours. The method disclosed by the invention is clean and environment-friendly, and can be used for preparing the catalyst with good catalytic performance.

According to the present disclosure, in step (2), the second reaction product may be an oil phase, i.e. the second reaction product contains only the oil phase without the aqueous phase, and is not layered on standing. The oil phase second reaction product contains both the first organic acid radical and the second organic acid radical stably combined with molybdenum.

According to the present disclosure, in step (1), the molar ratio of the molybdenum source to the amount of the first organic acid, calculated as molybdenum element, may be 1: (2-5), preferably 1: (2.3-4.6); in the step (2), the molar ratio of the first product to the second organic acid used in terms of molybdenum element may be 1: (2-8), preferably 1: (2.5-7.5).

According to the present disclosure, in the step (2), the mixing manner of the first product and the second organic acid is not particularly limited, and for example, the first product may be added to the second organic acid, or the second organic acid may be added to the first product, and preferably, the second organic acid is added dropwise to the first product; in one embodiment, the second organic acid may be added dropwise to the first product at a reaction temperature, and the reaction may be continued after the addition is completed, where the reaction time refers to a total time from the start of the addition to the end of the continuous reaction, that is, the reaction time includes a time of the addition; for example, the second organic acid is added dropwise to the first product at 150-300 ℃, the reaction is continued for 3-6 hours, preferably 3-5 hours after the completion of the addition, the addition time can be 5-60 minutes, and the solvent is removed by distillation under reduced pressure after the completion of the reaction.

According to the present disclosure, the solvent may be selected from water and/or an organic solvent; the organic solvent may be selected from benzene, toluene, ethanol or petroleum ether; the weight ratio of the water to the organic solvent can be (0-1): 1, preferably (0.3-0.5): 1, a step of; the weight ratio of the molybdenum source to the solvent amount may be 1: (5-30), preferably 1: (8-25).

The molybdenum source may be well known to those skilled in the art in light of the present disclosure, for example, selected from one or more of molybdenum trioxide, ammonium molybdate, and ammonium paramolybdate.

According to the present disclosure, in step (1), the first organic acid may be one or more of formic acid, acetic acid, oxalic acid, propionic acid, and valeric acid. In the step (2), the second organic acid may be one or more of heptanoic acid, 2-propylheptanoic acid, octanoic acid, isooctanoic acid, 2-ethylhexanoic acid, nonanoic acid, 2-phenylpropionic acid, phenylacetic acid, phthalic acid, isophthalic acid, terephthalic acid, suberic acid, and pimelic acid.

A third aspect of the present disclosure provides a catalyst for reducing sulfur content in petroleum coke, prepared by the method provided in the second aspect of the present disclosure.

wherein the catalyst is the catalyst for reducing the sulfur content in petroleum coke provided in the first aspect of the disclosure or the third aspect of the disclosure.

The method can produce low-sulfur petroleum coke, and the sulfur content in the petroleum coke can be reduced by at least 50%; transferring sulfur in petroleum coke into gas phase for recycling, so as to meet the requirement of environmental protection; meanwhile, the method disclosed by the invention has the advantages of less catalyst consumption, high catalytic efficiency, no need of separating the catalyst after reaction and simplified process flow.

In one embodiment, the method may further comprise: the obtained sulfur-containing cracked gas enters a flue gas adsorption desulfurization reactor and is contacted and reacted with an adsorption desulfurization catalyst to obtain purified cracked gas; and (3) reacting the adsorption-saturated adsorption desulfurization catalyst with reducing gas to obtain a regenerated catalyst and elemental sulfur.

According to the present disclosure, in step (1), the weight ratio of residuum, dilution solvent, and catalyst amounts is 1: (0.5-2.5): (0.02-0.05), preferably 1: (0.5-1.5): (0.02-0.04).

According to the present disclosure, the oxidizing agent may be hydrogen peroxide, and the molar ratio of hydrogen peroxide to sulfur in the residuum may be (1-10): 1, preferably (2-5): 1. preferably, hydrogen peroxide is added to the reaction mass at a constant rate, which may be hydrogen peroxide addition/reaction time.

According to the present disclosure, in step (1), the operating conditions of the oxidative desulfurization reaction may be: the reaction temperature is 70-90 ℃, the reaction time is 0.7-1.5h, preferably, the reaction temperature is 75-85 ℃, and the reaction time is 0.7-1h.

According to the present disclosure, in step (2), removing the diluent solvent in the reacted residuum may include: and (3) delivering the reacted residual oil into an atmospheric distillation tower or a vacuum distillation tower for distillation, wherein the temperature of the top of the tower can be 70-350 ℃, the temperature of the bottom of the tower can be 200-350 ℃, obtaining a mixture of a diluting solvent and water from the top of the tower, cooling and separating the mixture at 100-50 ℃, and returning the separated diluting solvent to the step (1) for recycling.

According to the present disclosure, the conditions for delayed coking may be: the outlet temperature of the delayed coking heating furnace is 490-500 ℃, the pressure is 0.1-0.25MPa, and the circulation ratio is 0-0.4.

According to the present disclosure, the diluent solvent may be one or more of coker diesel, coker gasoline, catalytic diesel, or kerosene refinery fractions having a final boiling point of less than 350 ℃, and chemical solvents such as toluene.

The present disclosure is further illustrated by the following examples, but the present disclosure is not limited thereby.

The chemicals used in the examples and comparative examples of the present disclosure were all products of the national pharmaceutical group chemical company, inc., and the residue used was taken from a vacuum apparatus of a Fujian refinery, and the raw material properties of the residue are shown in Table 1.

The analysis method of sulfur content in petroleum coke comprises the following steps: the method is measured by an oxidation combustion infrared COKE-CS method developed by the institute of petrochemical engineering.

The mass percent of molybdenum in the organomolybdenum compound was tested using ASTM D5185 method.

The acid value of the organomolybdenum compound was determined according to GB7304 standard using potentiometric methods.

Infrared spectroscopic testing of organomolybdenum compounds was performed in a fourier transform infrared spectrometer model Nicolet 6700 from zemoeimer, feier company, at a resolution of 4cm ^-1 Scanning for 16 times, and using GB/T6040-2002 infrared spectrum analysis method.

The desulfurization rate in petroleum coke is a blank value of sulfur content in petroleum coke after coking residual oil which is not subjected to oxidative desulfurization treatment, and the desulfurization rate= (blank value-sulfur content in petroleum coke after oxidative desulfurization) ×100/blank value.

Example 1

(1) The mass ratio of the molybdenum trioxide to the water to the toluene is 1:8:2 dispersing in a flask, adding oxalic acid at 95 ℃ for reaction for 2 hours, wherein the mole ratio of molybdenum trioxide to the consumption of oxalic acid calculated by molybdenum element is 1:2, obtaining a first product;

(2) At 200 ℃, isooctanoic acid is added dropwise into the first product for 10min, and the second product is obtained after the completion of the dropwise addition and the continuous reaction for 6 hours, wherein the molar ratio of molybdenum trioxide to isooctanoic acid is 1:3. when the second product is an oil phase, the solvent in the second product is removed by distillation under reduced pressure to obtain the organic molybdenum compound A1. The physicochemical properties of the organomolybdenum compounds are shown in Table 2.

The infrared spectrum of the organic molybdenum compound A1 is shown in FIG. 1, and from FIG. 1, 1500cm can be seen ^-1 The vicinity has asymmetric and symmetric stretching vibration peak of COO- (isooctanoate) at 1620cm ^-1 The asymmetric and symmetric stretching vibration peaks of the oxalic acid radical are positioned, and two kinds of carboxylic acid radicals in the product can be determined. Quantitative analysis is carried out on the peak areas of the two carboxylate radicals by an infrared spectrogram, and the molar ratio of the oxalate radical to the isooctanoate radical in the organic molybdenum compound is 0.15:1.

example 2

(1) Will (NH) ₄ ) ₆ Mo ₇ O ₂₄ The mass ratio of the water to the water is equal to 1:20 are dissolved and dispersed in a flask, purged with inert gas, and acetic acid is added at a temperature of 75 ℃ for reaction for 2 hours, calculated as molybdenum element (NH ₄ ) ₆ Mo ₇ O ₂₄ The molar ratio to acetic acid is 1:4, obtaining a first product;

(2) Dropping at 180℃into the first productAdding isooctanoic acid for 30min, and reacting for 5.5 hr to obtain a second product (NH based on molybdenum element) ₄ ) ₆ Mo ₇ O ₂₄ The molar ratio of the isooctanoic acid to the isooctanoic acid is 1:6. when the second product is an oil phase, the solvent in the second product is distilled off under reduced pressure to obtain an organomolybdenum compound A2, the physicochemical properties of which are shown in Table 2.

The infrared spectrum of the organic molybdenum compound A2 is shown in FIG. 2, and as can be seen from FIG. 2, the Mo atom and the carboxyl group RCOO ^- Bonding, 1500cm ^-1 With COO in the vicinity ^- The asymmetric and symmetric stretching vibration of (isooctanoate) can be used for determining that the synthesized compound is an organic molybdenum compound, and the concentration is 1625cm ^-1 The asymmetric and symmetric stretching vibration of the acetate radical can determine that two carboxylate radicals exist in the product. Quantitative analysis is carried out on the peak areas of the spectra of the two carboxylate radicals, and the molar ratio of the acetate radical to the isooctanoate radical in the organic molybdenum compound is 0.23:1.

example 3

(1) Molybdenum trioxide, water and ethanol according to the mass ratio of 1:12:4 dispersing in a flask, adding formic acid at 60 ℃ for reaction for 1 hour, wherein the mole ratio of molybdenum trioxide to the dosage of the formic acid calculated by molybdenum element is 1:4, obtaining a first product;

(2) 2-ethylhexanoic acid is dripped into the first product at 260 ℃ for 23min, and the reaction is continued for 3.62 hours after the dripping is completed to obtain a second product, wherein the mol ratio of molybdenum trioxide to 2-ethylhexanoic acid is 1:7. when the second product is an oil phase, the solvent in the second product is distilled off under reduced pressure to obtain an organomolybdenum compound A3, the physicochemical properties of which are shown in Table 2. Quantitative analysis of the peak areas of the spectra of the two carboxylates showed that the molar ratio of formate to 2-ethylhexyl in the organomolybdenum compound was 0.18:1.

example 4

(1) The mass ratio of the molybdenum trioxide to the water to the toluene is 1:8:2 dispersing in a flask, adding oxalic acid at 90 ℃ for reaction for 3 hours, wherein the mole ratio of molybdenum trioxide to the consumption of oxalic acid calculated by molybdenum element is 1:3, obtaining a first product;

(2) At 200 ℃, isooctanoic acid is added dropwise into the first product for 10min, and the second product is obtained after the completion of the dropwise addition and the continuous reaction for 9 hours, wherein the molar ratio of molybdenum trioxide to isooctanoic acid is 1:5. when the second product is an oil phase, the solvent in the second product is removed by distillation under reduced pressure to obtain the organic molybdenum compound A4. The physicochemical properties of the organomolybdenum compounds are shown in Table 2. Quantitative analysis is carried out on the peak areas of the spectra of the two carboxylate radicals, and the molar ratio of the oxalate radical to the isooctanoate radical in the organic molybdenum compound is 0.03:1.

example 5

(1) The mass ratio of the molybdenum trioxide to the water to the toluene is 1:8:2 dispersing in a flask, adding oxalic acid at 95 ℃ for reaction for 3 hours, wherein the mole ratio of molybdenum trioxide to the consumption of oxalic acid calculated by molybdenum element is 1:3, obtaining a first product;

(2) At 200 ℃, isooctanoic acid is added dropwise into the first product for 10min, and the second product is obtained after the completion of the dropwise addition and the continuous reaction for 6 hours, wherein the molar ratio of molybdenum trioxide to isooctanoic acid is 1:1.8. when the second product is an oil phase, the solvent in the second product is removed by distillation under reduced pressure to obtain the organic molybdenum compound A5. The physicochemical properties of the organomolybdenum compounds are shown in Table 2. Quantitative analysis is carried out on the peak areas of the spectra of the two carboxylate radicals, and the molar ratio of the oxalate radical to the isooctanoate radical in the organic molybdenum compound is 0.17:1.

example 6

(1) The mass ratio of the molybdenum trioxide to the water to the toluene is 1:8:2 dispersing in a flask, adding oxalic acid at 95 ℃ for reaction for 3 hours, wherein the mole ratio of molybdenum trioxide to the consumption of oxalic acid calculated by molybdenum element is 1:5, obtaining a first product;

(2) At 200 ℃, isooctanoic acid is added dropwise into the first product for 10min, and the second product is obtained after continuous reaction for 6 hours, wherein the mol ratio of molybdenum trioxide to isooctanoic acid is 1:14. when the second product is an oil phase, the solvent in the second product is removed by distillation under reduced pressure to obtain the organic molybdenum compound A6. The physicochemical properties of the organomolybdenum compounds are shown in Table 2. Quantitative analysis is carried out on the peak areas of the spectra of the two carboxylate radicals, and the molar ratio of the oxalate radical to the isooctanoate radical in the organic molybdenum compound is 0.11:1.

test examples 1 to 7

The rapid coking experiments were carried out using examples 1 to 6 and molybdenum isooctanoate (molybdenum isooctanoate having a metal molybdenum content of 15.2% by weight, an infrared spectrum as shown in FIG. 3, and a solubility as shown in Table 2) as catalysts, in turn as test examples 1 to 7. Toluene was used as a diluent solvent in a ratio of 1 with residuum (from foggy vacuum residuum): 1, dilution is performed. 100g of diluted residual oil is weighed respectively, 2g of catalyst is added, 38 wt% of hydrogen peroxide is added at the speed of 0.5g/min at the temperature of 85 ℃, and the reaction time is 1h. The reaction product is distilled to remove the diluting solvent to obtain oxidized residual oil, and the mixture of toluene and water is distilled out by vacuum distillation.

2g of oxidized residual oil is introduced into a delayed coking device for quick coking experiment, the reaction temperature is 470-480 ℃, the reaction time is 1h, petroleum coke B1-B7 is obtained, the sulfur content in the petroleum coke is analyzed, and the experimental result is shown in Table 3.

Test example 8

And directly carrying out a rapid residual oil coking experiment on the residual oil raw material to obtain petroleum coke B8.

The rapid residual oil coking experimental method comprises the following steps: weighing 2g of residual oil sample, placing the residual oil sample into a quartz glass test tube, heating the coking reactor to 500 ℃ under the protection of nitrogen, rapidly placing the residual oil sample into the coking reactor, reacting for 1h, removing the quartz glass test tube into air, cooling, weighing and sampling after cooling, and the experimental results are shown in table 3.

TABLE 1

TABLE 2

TABLE 3 Table 3

As can be seen from table 3, the catalyst containing the organomolybdenum compound of the present disclosure has good oil solubility and proper acid value distribution, and has higher selectivity for sulfur oxidation than the oil-soluble organomolybdenum catalyst in the prior art, and is particularly suitable for the oxidative desulfurization process of residual oil.

The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, but the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.

In addition, the specific features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, the present disclosure does not further describe various possible combinations.

Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.

Claims

1. A method of producing low sulfur petroleum coke, the method comprising:

(1) Mixing residual oil, a diluting solvent, an oxidant and a catalyst to perform oxidation desulfurization reaction to obtain a mixture containing desulfurized residual oil, and removing the diluting solvent in the mixture to obtain desulfurized residual oil; in the step (1), the operation conditions of the oxidative desulfurization reaction are as follows: the reaction temperature is 70-90 ℃ and the reaction time is 0.7-1.5h;

(2) Introducing the desulfurized residual oil into a delayed coking reaction device for delayed coking to obtain a low-sulfur petroleum coke product and sulfur-containing cracked gas; the conditions of the delayed coking are as follows: the outlet temperature of the delayed coking heating furnace is 490-500 ℃, the pressure is 0.1-0.25MPa, and the circulation ratio is 0-0.4;

the catalyst contains an oil-soluble organic molybdenum compound, and anions of the oil-soluble organic molybdenum compound comprise a first organic acid radical and a second organic acid radical; the first organic acid radical is a C1-C6 oxygen-containing organic acid radical, and the second organic acid radical is a C7-C16 oxygen-containing organic acid radical; the acid value of the catalyst is 380-440mg KOH/kg; the molar ratio of the first organic acid radical to the second organic acid radical is (0.15-0.2): 1, a step of; the content of molybdenum element in the oil-soluble organic molybdenum compound is 12-18 wt%.

2. The method of claim 1, wherein the first organic acid radical is a C1-C6 monocarboxylate, a dicarboxylic acid radical, or a polycarboxylic acid radical; the second organic acid radical is monocarboxylate, dicarboxylic acid radical or polycarboxylic acid radical of C7-C16.

3. The method according to claim 1, wherein the first organic acid radical is selected from one or more of formate, acetate, oxalate, propionate and valerate;

4. The method of claim 1, wherein the method of preparing the catalyst comprises:

(2) Reacting the first product with a second organic acid at 150-300 ℃ for 2-10 hours to obtain a second product; the molar ratio of the molybdenum source to the amount of the second organic acid calculated as molybdenum element is 1: (1-15);

wherein the first organic acid is C1-C6 oxygen-containing organic acid, the second organic acid is C7-C16 oxygen-containing organic acid, and the molar ratio of the first organic acid radical to the second organic acid radical in the catalyst is (0.15-0.2): 1.

5. the method of claim 4, wherein the second product is an oil phase.

6. The method of claim 4, wherein in step (1), the molar ratio of the molybdenum source to the amount of the first organic acid, calculated as elemental molybdenum, is 1: (2-5);

in the step (2), the molar ratio of the molybdenum source to the second organic acid used in terms of molybdenum element is 1: (2-8), wherein the molar ratio of the first organic acid radical to the second organic acid radical in the catalyst is (0.15-0.2): 1.

7. the method of claim 4, wherein step (2) comprises: and (3) dropwise adding the second organic acid into the first product within 5-60min at 150-300 ℃, continuing to react for 3-6h after the dropwise adding is finished, and removing the solvent through reduced pressure distillation after the reaction is finished.

8. The method of claim 4, wherein the solvent is selected from water and/or an organic solvent; the organic solvent is selected from benzene, toluene, ethanol or petroleum ether;

the weight ratio of the molybdenum source to the solvent dosage calculated by molybdenum element is 1: (5-30).

9. The method of claim 8, wherein the solvent is selected from the group consisting of water and an organic solvent, the weight ratio of water to the amount of organic solvent being 1: (0-1).

10. The method of claim 4, wherein the molybdenum source is selected from one or more of molybdenum trioxide, ammonium molybdate, and ammonium paramolybdate.

11. The method of claim 4, wherein in step (1), the first organic acid is one or more of formic acid, acetic acid, oxalic acid, propionic acid and valeric acid;

12. The process of claim 1, wherein in step (1), the residual oil, the diluent solvent, and the catalyst are used in a weight ratio of 1: (0.5-2.5): (0.02-0.05).

13. The process of claim 1, wherein the oxidizing agent is hydrogen peroxide, the molar ratio of hydrogen peroxide to sulfur in the residuum being (1-10): 1.

14. the method of claim 1, wherein in step (1), removing the diluent solvent from the residual oil after the oxidative desulfurization reaction comprises: and (2) delivering the residual oil after the oxidative desulfurization reaction into an atmospheric distillation tower or a vacuum distillation tower for distillation, wherein the temperature of the top of the tower is 70-350 ℃, the temperature of the bottom of the tower is 200-350 ℃, obtaining a mixture of a diluting solvent and water from the top of the tower, cooling and separating the mixture of the diluting solvent and water at 50-100 ℃, and returning the separated diluting solvent to the step (1) for recycling.