RU2806008C1 - Method for producing anode coke from crude oil - Google Patents

Abstract

FIELD: oil refining.

SUBSTANCE: group of inventions is related in particular to methods for producing anode coke in a delayed coking unit (DCU). The method includes: loading hydrocarbon feedstock (1; 32) into a desalting unit (2; 33) to obtain a desalted crude oil stream (3; 34); redirection of the desalted stream (3; 34) to the preseparator chamber (4; 35) to obtain a stream of lighter fractions (5; 36) with a boiling point < 300°C and a stream of heavier fractions with a boiling point > 300°C; direction of flow of heavier fractions into the furnace (8; 39); feeding the heated stream (9; 40) leaving the furnace (8; 39) into coke drums (12/13; 43/44) to produce lighter hydrocarbons and coke by cracking; the direction of the flow leaving the drums (16; 47) into the main fractionating unit (17; 49) to produce light coking gas oil, heavy coking gas oil, petroleum fuel; mixing a stream of gaseous products (18; 50) from the main fractionation unit (17; 49) with a stream of lighter fractions (5; 36) with a boiling point < 300°C; transferring the crude petroleum coke (25; 57) obtained from the coke drum to a feed hopper (26; 58) and receiving a feed stream for calcination (27; 59); and calcination of crude petroleum coke (27; 59) in a furnace (28; 60) and transferring the calcined coke (29; 61) to a cooling unit (30; 62) to obtain anode coke (31; 63).

EFFECT: production of anode coke with a low content of impurities directly from crude oil in the ultrasonic unit and with higher quality, in which technological limitations in the operation of ultrasonic units associated with the processing of crude oil are eliminated, as well as the maximum recovery of lighter boiling fractions in the production of anode coke.

12 cl, 2 dwg, 12 tbl, 3 ex

Description

TECHNICAL FIELD:

The present invention relates to the field of petroleum refining and, in particular, to a method for producing anode coke as compared to fuel petroleum coke directly from crude oil by using a processing technique different from the commonly used delayed coker (DCO) technique.

PREREQUISITES FOR CREATION OF THE INVENTION:

Crude oil is a complex mixture of thousands of chemicals, most of which are hydrocarbons, i.e. substances consisting of carbon and hydrogen. Some chemicals in crude oil include other elements (called "heteroelements") such as sulfur, nitrogen, and metals such as vanadium or nickel. Crude oil from different regions of the planet varies significantly in composition; the types and relative amounts of compounds it contains can vary greatly. For example, heavy crude oil has a relatively higher content of large hydrocarbon molecules, while light crude oil contains a relatively higher amount of small hydrocarbon molecules. Sweet oils have low sulfur content (typically less than 0.5 weight percent), while sour oils contain higher amounts of sulfur (typically 1-2 weight percent or more).

Residues are the fractions remaining after crude oil is distilled in an atmospheric distillation unit (ADU) and a vacuum distillation unit (VDU). The residual fraction obtained from the bottom of the APU, which is also called atmospheric distillation fuel oil (MASU), is further divided into fractions in the APU. The residual fraction obtained in the VPU is a heavy asphaltene, which includes a fraction with a high content of sulfur, metals, nitrogen, and this raw material is called vacuum distillation fuel oil (MVF), which is processed in the thermal cracking unit of an oil refinery. The thermal cracking process widely used to clean up petroleum residues is called delayed coking. In its process, petroleum residues are heated and thermally cracked to produce valuable, relatively low-boiling products from petroleum distillate and a solid carbonaceous residue known as coke. Coke with high sulfur and/or metal content is usually burned as fuel. Fuel coke generally has no other uses.

Petroleum coke (also called petcoke or simply coke) is a high-carbon product obtained from the thermal cracking of heavy residues in an ultrasonic unit. The commercial value of coke depends on the amount of impurities such as sulfur, metals, nitrogen, etc., as well as its crystalline structure. Coke with a relatively high sulfur content is called fuel coke, which is sold as fuel for coal-fired boilers, typically used for energy generation. The sulfur content in fuel coke is 6-8% by weight. Anodic coke is a coke produced from UCC with relatively low impurity content and an improved crystal structure compared to fuel coke used to create electrodes in aluminum production.

US Pat. No. 10351778 B2 describes methods and systems for producing anode coke from high sulfur crude oil. The crude oil undergoes atmospheric distillation and the residue after distillation is separated into different parts. One part is hydrotreated while the other is solvent deasphalted. The synthetic product stream resulting from mixing the hydrotreated residue stream and one or more solvent deasphalting streams is used to produce anode coke. The proposed process in the prior art is quite complex and may not be cost-effective since it is expected that hydrotreating the residues may require very large amounts of hydrogen.

WO 2012/162008A1 describes other options for delayed coking of a crude oil stream. The fresh crude oil stream is mixed with the bottoms stream from the coker fractionator and heated to a temperature of 480-530°C in the coker oven. After this, the stream coming from the coker oven is redirected to the coke drum for coking. The vapors emanating from the coke drum undergo instantaneous separation, resulting in a light gaseous product stream and a highly boiling stream. This boiling stream is sent to the main fractionator with recirculated heavy gas oil.

US Pat. No. 6,332,975 B1 describes a process for deasphalting a residue stream to produce tar and asphaltene fractions and subsequently producing anode coke by coking the hydrotreated tar fraction. It describes the hydrotreating of (1) a small portion of petroleum residues, in which the hydrotreated residue is fed to a delayed coker along with the resin stream, (2) a resin stream, in which the hydrotreated resin stream is fed to the delayed coker, and (3) most of the oil residues, in which the tar-containing stream is fed to a solvent deasphalting unit.

There is a definite requirement for the development of alternative, improved methods for the production of anode coke. The present invention provides for the production of higher quality anode coke using crude oil. The present invention also provides for mixing a stream with a high content of aromatic petroleum residues with crude oil, which allows to solve the technological problem associated with the processing of petroleum feedstocks with a high content of paraffins, as well as to improve the quality of the coke.

OBJECTIVES OF THE PRESENT INVENTION:

The main object of the present invention is to provide a method for producing coke with low impurity content directly from crude oil.

Another object of the present invention is to provide a method for producing anode coke in a delayed coker (DCU).

Another purpose of the present invention is to propose a method for eliminating technological limitations in the operation of ultrasonic units associated with the processing of crude oil.

Another object of the present invention is to produce less coke with higher quality, meeting the requirements for anode coke.

Another goal of the present invention is to maximize the recovery of lighter boiling fractions in the production of anode coke.

SUMMARY OF THE INVENTION:

The present invention is a method for producing anode coke directly from crude oil using ultrasonic testing. One embodiment of the present invention provides a method for producing anode coke in an ultrasonic unit, which includes:

i. loading hydrocarbon feedstock (1; 32) into a desalting unit (2; 33) to obtain a desalted crude oil stream (3; 34);

ii. redirection of the desalted stream (1; 34) to the preseparator chamber (4; 35) to obtain a stream of lighter fractions (5; 36) with a boiling point < 300°C and a stream of heavier fractions with a boiling point ˃ 300°C;

iii. directing the flow of high aromatic oil residues such as clear light oil (6) into the bottom of the pre-separator chamber (4) to separate the fraction of crude oil with a boiling point less than 300°C from the clear light oil and mix with the fraction of crude oil with a point boiling over 300°C to obtain a flow of heavier fractions;

iv. direction of flow of heavier fractions into the furnace (8; 39);

v. feeding the heated stream (9; 40) leaving the furnace (8; 39) into coke drums (12/13; 43/44) to produce lighter hydrocarbons and coke by cracking;

vi. direction of the flow leaving the drums (16; 47) to the main fractionating unit (17; 49) to produce light coking gas oil, heavy coking gas oil, petroleum fuel;

vii. mixing the stream of gaseous products (18; 50) from the main fractionation unit (17; 49) with the stream of lighter fractions (5; 36) with a boiling point < 300°C;

viii. transferring the crude petroleum coke (25; 57) obtained from the coke drum to a feed hopper (26; 58) and receiving a feed stream for calcination (27; 59); And

ix. calcination of crude petroleum coke (27; 59) in a furnace (28; 60) and transfer of calcined coke (29; 61) to a cooling unit (30; 62) to obtain anode coke (31; 63).

One embodiment of the present invention provides a method for producing anode coke in an ultrasonic unit, which includes:

i. loading hydrocarbon feedstock (1; 32) into a desalting unit (2; 33) to obtain a desalted crude oil stream (3; 34);

ii. redirection of the desalted stream (1; 34) to the preseparator chamber (4; 35) to obtain a stream of lighter fractions (5; 36) with a boiling point < 300°C and a stream of heavier fractions with a boiling point ˃ 300°C;

iii. direction of flow with a high content of aromatic petroleum residues, such as clarified light oil (48) into the main fractionation unit of the ultrasonic unit (49) as a wash oil product, where the lighter fraction of the clarified light oil is separated, and the heavier fraction is used to wash the vapors coming from coke drum, to obtain a return flow (38), which is mixed with the flow of heavier fractions (37) from the preseparator chamber (35);

iv. direction of flow of heavier fractions into the furnace (8; 39);

v. feeding the heated stream (9; 40) leaving the furnace (8; 39) into coke drums (12/13; 43/44) to produce lighter hydrocarbons and coke by cracking;

vi. direction of the flow leaving the drums (16; 47) to the main fractionating unit (17; 49) to produce light coking gas oil, heavy coking gas oil, petroleum fuel;

vii. mixing the stream of gaseous products (18; 50) from the main fractionation unit (17; 49) with the stream of lighter fractions (5; 36) with a boiling point < 300°C;

viii. transferring the crude petroleum coke (25; 57) obtained from the coke drum to a feed hopper (26; 58) and receiving a feed stream for calcination (27; 59); And

ix. calcination of crude petroleum coke (27; 59) in a furnace (28; 60) and transfer of calcined coke (29; 61) to a cooling unit (30; 62) to obtain anode coke (31; 63).

In another embodiment of the present invention, the hydrocarbon feedstock (1; 32) is selected from a group of feedstocks consisting of various crude oils, sour oils, sweet oils, low-cost crude oils, and heavier streams derived therefrom.

In another embodiment of the present invention, coke drums (12, 13; 43, 44) are used at a temperature of 430 - 460 ° C at the top and a pressure of 1-5 kg/cm ² (g), and the temperature of the heated stream (9; 40), coming from the furnace (8; 39) is in the range from 480°C to 510°C.

In one preferred embodiment, the stream of heavier fractions with a boiling point of ˃ 300°C in step (ii) is mixed with a stream with a high content of aromatic oil residues (6) and is directed through the bottom of the pre-separator chamber.

In another embodiment of the present invention, the high aromatic petroleum residue stream (6) is selected from the group of substances including pyrolysis tar, high temperature tar, and clarified light oil.

In another embodiment of the present invention, the heavier fractions stream with a boiling point of ˃ 300°C, obtained in step (ii), is mixed with the return stream (38) before it is redirected to the furnace (39).

In another embodiment of the present invention, the coke drum effluent stream (47) in the main fractionation unit is washed with a high aromatic petroleum residue stream (48) to condense heavier molecules from the coke drum effluent stream (47) and produce return stream (38), and the stream with a high content of aromatic oil residues (48) is selected from a group of substances including pyrolysis tar, high-temperature tar, clarified light oil.

In one of the preferred embodiments of the present invention, the content of sulfur and nitrogen in the resulting coke is ≤ 3% by weight. and 0.1 wt.%, respectively, and the coke corresponds to the quality specified for anode coke.

In one embodiment of the present invention, there is provided a method comprising:

i. loading hydrocarbon feedstock (1) into a desalting unit (2) to obtain a desalted crude oil stream (3);

ii. redirection of the desalted stream (3) to the preseparator chamber (4) to obtain a stream of lighter fractions (5) with a boiling point < 300°C and a stream of heavier fractions with a boiling point ˃ 300°C;

iii. directing clarified light oil with a high content of aromatic oil residues (6) to the lower part of the preseparator chamber (4) to separate the fraction with a boiling point less than 300 ^° C from the clarified light oil and mix with the flow of heavier fractions;

iv. directing a mixed fraction stream (7), consisting of heavier fractions from crude oil and a stream of clarified light oil (6), into a furnace (8) for heating to cracking temperature;

v. feeding the heated stream (9) leaving the furnace (8) into coke drums (12/13) to produce lighter hydrocarbons and coke by cracking;

vi. direction of the flow leaving the drum (16) to the main fractionating unit (17) to produce light coking gas oil (20), heavy coking gas oil (21), petroleum fuel (22);

vii. mixing the stream of gaseous products (18) from the main fractionation unit (17) with the stream of lighter fractions (5) with a boiling point < 300°C;

viii. transferring the crude petroleum coke (25) obtained from the coke drum to a feed hopper (26) and receiving a calcination feed stream (27); And

ix. calcination of raw petroleum coke (27) in a furnace (28) and transfer of the calcined coke (29) to a cooling unit (30) to obtain anode coke (31).

In yet another embodiment of the present invention, there is provided a method comprising:

i. loading hydrocarbon feedstock (32) into a desalting unit (33) to produce a desalted crude oil stream (34);

ii. redirection of the desalted stream (34) to the preseparator chamber (35) to obtain a stream of lighter fractions (36) with a boiling point < 300°C and a stream of heavier fractions with a boiling point ˃ 300°C;

iii. adding the recycle stream (38) to the heavy ends stream (37) and sending them to a furnace (39) for heating to cracking temperature;

iv. feeding the heated stream (40) leaving the furnace (39) into coke drums (43/44) to produce lighter hydrocarbons and coke by cracking;

v. direction of the flow leaving the drum (47), which is washed with a stream with a high content of aromatic oil residues (48), into the main fractionation unit (49) to obtain light coker gas oil (52), heavy coker gas oil (53), fuel oil (54 ) and for the condensation of heavier molecules to produce a return flow (38);

vi. mixing a stream of gaseous products (50) from the main fractionation unit (49) with a stream of lighter fractions (36) with a boiling point < 300°C; And

vii. transferring the crude petroleum coke (57) obtained from the coke drum to a feed hopper (58) and receiving a feed stream (59) for calcination;

viii. calcination of crude petroleum coke (59) in a furnace (60) and transferring the calcined coke (61) to a cooling unit (62) to obtain anode coke (63).

Brief description of drawings:

Figure 1: Shows Embodiment 1 of the present invention.

Figure 2: Shows Embodiment 2 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION:

To provide an understanding of the principles of the present invention, specific embodiments will be described as well as drawings, and specific language will be used throughout the text. The above general description and the following detailed description are explanatory of the present invention and are not limiting. However, it should be understood that the scope of the present invention is not intended to be limiting, and changes and further modifications to the described method, as well as additional applications of the principles of the present invention described herein, should be considered from the point of view of one skilled in the art to which it relates. the present invention. Unless otherwise specified, all technical and scientific terms used herein have the meaning commonly understood by one skilled in the art to which the present invention relates. The methods and examples presented herein are purely descriptive and are not intended to be limiting in any way.

Anode coke is a type of coke product obtained from a delayed coker, having a sponge-like structure with a relatively low content of sulfur and impurities such as metals, nitrogen, etc.

Raw materials:

The feedstocks within the scope of the present invention are selected from sour/sweet crude oils, low-cost crude oils. Aromatic oils are selected from oils such as clarified light oil (CLO), high temperature tar, and pyrolysis tar.

The main embodiment of the present invention provides a method for producing anode coke by treating crude oil in a delayed coker, which includes:

i. loading hydrocarbon feedstock into a desalting unit to produce a desalted crude oil stream;

ii. redirection of the demineralized flow into the preseparator chamber to obtain a flow of lighter fractions with a boiling point < 300°C and a flow of heavier fractions with a boiling point ˃ 300°C;

iii. directing the flow with a high content of aromatic oil residues into the lower part of the pre-separator chamber and mixing with the flow of heavier fractions, and in the pre-separator a lighter fraction of the flow with a high content of aromatic oil residues is recovered along with a stream of crude oil with a boiling point of <300 ^° C;

iv. directing the flow of mixed fractions into a furnace for heating to cracking temperature;

v. supplying the heated stream from the furnace to the coke drum(s) to produce lighter hydrocarbons and coke by cracking;

vi. directing the flow leaving the drums to the main fractionation unit to produce light coking gas oil, heavy coking gas oil, and petroleum fuel;

vii. mixing the stream of gaseous products from the main fractionation unit with the stream of lighter fractions with a boiling point < 300°C; And

viii. transferring the raw petroleum coke obtained from the coke drum to the raw material hopper, calcining the raw coke leaving the hopper in a furnace and sending it to a cooling unit to produce anode coke.

In another embodiment of the present invention, the crude oil feed stream is separated in a pre-separator chamber to produce lighter components (boiling point less than 300°C) from heavier crude oil molecules containing a fraction with a boiling point greater than 300°C.

In another preferred embodiment of the present invention, a method is provided to overcome technological limitations in the operation of ultrasonic units associated with the processing of crude oil. Heavy fraction streams (boiling points above 300°C) are mixed with a stream containing high aromatic petroleum residues, such as pyrolysis tar, high temperature tar, clarified light oil (CLO), etc., and are subsequently sent to the coker oven. and into coke drums.

In another embodiment of the present invention, the hydrocarbon feedstock used in the process is a variety of crude oils: sour and sweet crude oils, low-cost crude oils, and heavier streams derived from them.

Technological method conditions:

The process described herein is carried out by maintaining the oven coil outlet temperature in the range of 480°C to 510°C and the top of the coke drum in the range of 430°C to 460°C. The operating pressure of the technological method is 1-5 kg/cm ² (g).

Option I

A schematic flow diagram of one embodiment of the present invention is shown in Figure 1, and according to it, all or part of the crude oil feedstock (1) is desalted in a desalting unit (2) to produce a desalted stream (3). The desalted stream (3) is then sent to a preseparator chamber (4) to separate the stream (5) with a boiling point in the range below 300°C from the feed stream (3). The flow of clarified light oil (CLO) with a high content of aromatic oil residues (6) is directed to the lower part of the preseparator chamber (4). The lighter boiling value fraction (less than 300°C) of this OLM is separated in a stripping column, and the fraction with a boiling point above 300°C is mixed with material (3) with a boiling point above 300°C, resulting in a mixed stream raw materials (7). The mixed feed stream (7) is fed into the furnace (8) of the delayed coker. The heated stream (9) leaving the oven (8) is directed to the coke drum either (12) or (13), depending on which of them is included in the filling cycle, through (10) or (11). The mixed feedstock is cracked, resulting in the formation of lighter hydrocarbons in the coke drums. Stream (16) leaving the coke drums via lines (14) and (15) is then sent to the main fractionator (17). Product streams from (17), such as gases (18), after mixing with (5), are sent to further processing (19). The distillate fractions, light coking gas oil (20), heavy coking gas oil (21) and fuel oil (22), are sent for further processing. Coke (25) through lines (23) and (24), obtained from coke drums (12) and (13), is sent to the raw material hopper (26). After this, the raw coke (27) at the outlet of the bunker is calcined in the furnace (28) of the calcination unit. The calcined coke (29) is sent from the furnace (28) to the cooling unit (30), resulting in a calcined coke product (31) that meets the requirements for anode coke.

Option II

Another schematic flow diagram of one embodiment of the present invention, shown in Figure 2, involves desalting all or part of the crude oil feedstock (32) in a desalting unit (33) to produce a desalted stream (34). The desalted stream (34) is then sent to a preseparator chamber (35) to separate a stream (36) with a boiling point in the range below 300°C from the feed stream (34). The stream of fractions with a boiling point above 300°C (37) is mixed with the return stream (38) and sent to the furnace (39) of the delayed coker. The heated stream (40) leaving the oven (39) is directed to the coke drum either (43) or (44), depending on which one is included in the filling cycle, via line (41) or (42). The mixed feedstock is cracked, resulting in the formation of lighter hydrocarbons in the coke drums. The coke drum effluent stream (47) via lines (45) and (46) is then sent to the main fractionator (49) where the heavier molecules from the coke drum effluent stream (47) are condensed to produce a return stream (38). Product streams from (49), such as gases (50), after mixing with (36), are sent to further processing (51). The distillate fractions, light coking gas oil (52), heavy coking gas oil (53) and fuel oil (54), are sent for further processing. Coke (57) through lines (55) and (56), obtained from coke drums (43) and (44), is sent to the raw material hopper (58). After this, the raw coke (59) at the outlet of the bunker is calcined in the furnace (60) of the calcination unit. The calcined coke from (61) is sent to the cooling unit (62), resulting in a calcined coke product (63) that meets the requirements for anode coke.

Treating a fraction of crude oil with a boiling point above 300°C and mixing it with a stream containing high levels of aromatic petroleum residues can improve the quality of coke compared to coke obtained from vacuum distillation fuel oil feedstock.

Examples:

Example 1: Petroleum mixture A with the properties shown in Table 1 was thermally cracked in accordance with the process conditions specified in Table 2 in a laboratory thermal cracker to produce crude petroleum coke A (CPC A). The SNC obtained from the experiment was calcined in a batch calcination unit under the conditions given in Table 3 to obtain calcined petroleum coke A (PNC A). The properties of PNA are given in Table 4.

No. Properties of oil mixture A Meaning 1. Density, g/cm ³ 0.8908 2. coking according to Conradson, wt.% 8.21 3. Simulated distillation
5/10/30/50/70/90/95 165/210/285/358/458/582/786 4. Sulfur,% wt. 3 5. Nitrogen, wt.% 0.13 6. Metals, parts per million by weight
Ca/Fe/Mg/Na/Ni/V <1/2/<1/8/16/26

Table 1: Properties of oil mixture A

No. Parameter Meaning 1. Operating temperature, ^o C 486 2. Pressure, kg/cm ² (g) 1.8 3. Coke yield (Mixture A), wt.% 12.6

Table 2: Operating conditions and coke yield

No. Parameter Meaning 1. Temperature, ^o C 1250 2. Duration of processing, hours 4

Table 3: Calcination conditions

No. Parameter SNK A PNK A Characteristics of another type of coke 1. Sulfur,% wt. 5 2.5 2.5-3 (max.) 2. Nitrogen, wt.% 0.4 <0.1 - 3. Moisture, wt.% <1 0.22 0.3 (max) 4. Ash, wt.% 0.1 0.32 0.35 (max) 5. VMC, wt.% 8.9 0.46 0.5 (max) 6. Fixed carbon, wt.% 90.7 99.04 99 7. True density, g/cm ³ - 2.06 2.05-2.085 Metal content, ppm 8. Ni 127 152 200 (max) 9. V 207 247 250 (max) 10. Ni+V 334 399 350-450 (max) eleven. Na 64 159 100-300 (max) 12. Ca 8 16 100-200 (max) 13. Na+Ca 72 175 200 (max) 14. Fe 16 18 200-600 (max)

Table 4: Properties of coke obtained from petroleum mixture A

Coke with the properties listed in Table 4 was subjected to X-ray diffraction analysis to measure crystallite size (CS). The obtained LC value was 37 Å, which indicates the good quality of the crystal structure. It can be seen that all properties of PNA A obtained from crude oil fall within the range provided for anode coke.

Example2: Petroleum mixture A with the properties given in Table 1 was subjected to atmospheric distillation followed by vacuum distillation to produce vacuum distillation fuel oil (VFO), which is a common feedstock for use in crackers (Table 5). MEP was thermally cracked according to the process conditions specified in Table 6 to produce crude petroleum coke (CPC B). The SNK B obtained in this manner was subjected to calcination in a batch calcination unit under the conditions given in Table 7 to obtain calcined petroleum coke B (PNC B). The properties of the coke obtained in this way are shown in Table 8.

No. Properties Meaning 1. Density, g/cm ³ 1.0551 2. coking according to Conradson, wt.% 28 3. Simulated distillation
5/10/30/50/70/90/95 564/581/624/670/729/823/973 4. Sulfur,% wt. 6 5. Nitrogen, wt.% 0.4 6. Metals, parts per million by weight
Ca/Fe/Mg/Na/Ni/V 1/10/<1/49/57/170

Table 5: Properties of raw materials, which are vacuum distilled fuel oil from petroleum mixture A

No. Parameter Meaning 1. Operating temperature, ^o C 486 2. Pressure, kg/cm ² (g) 1.8 3. Coke yield (MVP), wt.% thirty

Table 6: Operating conditions and coke yield

No. Parameter Meaning 1. Temperature, ^o C 1250 2. Duration of processing, hours 4

Table 7: Calcination conditions

No. Parameter SNK B PNK B Characteristics of another type of coke 1. Sulfur,% wt. 8 3.4 2.5-3 (max.) 2. Nitrogen, wt.% 1.4 0.9 - 3. Moisture, wt.% <1 0.22 0.3 (max) 4. Ash, wt.% 0.12 0.4 0.35 (max) 5. VMC, wt.% 9.38 3.95 0.5 (max) 6. Fixed carbon, wt.% 90.19 95.47 99 7. True density, g/cm ³ - 2.05 2.06-2.08 Metal content, ppm 8. Ni 190 254 200 (max) 9. V 567 769 250 (max) 10. Ni+V 757 1023 350-450 (max) eleven. Na 163 320 100-300 (max) 12. Ca 4 7 100-200 (max) 13. Na+Ca 167 327 200 (max) 14. Fe 33 38 200-600 (max)

Table 8: Coke produced from MVP from mixture A

PNA B, described in Example 2, was subjected to X-ray diffraction analysis to measure crystallite size (LC). The obtained LC value was 34.7 Å, which indicates a less well formed crystal structure. In addition, metals such as vanadium, nickel and sodium were concentrated in the coke, resulting in poor coke quality. The content of impurities such as sulfur and nitrogen was also found to be high in SNK B and PNK B obtained from MPV.

Example 3: In another experiment, an aromatic residue stream of clarified light oil (CLO) with the properties listed in Table 9 was mixed with crude oil in a ratio of 10:90 and processed in a laboratory thermal cracker to produce crude petroleum coke B (CLP C). SNK B obtained from the experiment was calcined under the conditions given in Table 11 to obtain calcined petroleum coke B (PNK B). The properties of the resulting calcined coke are given in Table 12.

No. Properties Meaning 1. Density, g/cm ³ 1.1 2. coking according to Conradson, wt.% 15.9 3. Simulated distillation
5/10/30/50/70/90/95 219/320/360/386/422/478/524 4. Sulfur,% wt. 0.4 5. Nitrogen, wt.% 0.04 6. Metals, parts per million by weight
Ca/Fe/Mg/Na/Ni/V <1/<1/<1/<1/<1/<1

Table 9: OLM properties

No. Parameter Meaning 1. Operating temperature, ^o C 486 2. Pressure, kg/cm ² (g) 1.8 3. Coke yield, wt.% 20

Table 10: Operating conditions

No. Parameter Meaning 1. Temperature, ^o C 1250 2. Duration of processing, hours 4

Table 11: Calcination conditions

No. Parameter SNK V PNK B Characteristics of another type of coke 1. Sulfur,% wt. 4.7 2.3 2.5-3 (max.) 2. Nitrogen, wt.% 0.39 <1 - 2. Moisture, wt.% 0.51 0.08 0.3 (max) 3. Ash, wt.% 0.12 0.38 0.35 (max) 4. VMC, wt.% 3.74 0.48 0.5 (max) 5. Fixed carbon, wt.% 95.63 99.06 99 6. True density, g/cm ³ - 2.07 2.06-2.08 Metal content, ppm 8. Ni 116 138 200 (max) 9. V 187 223 250 (max) 10. Ni+V 303 361 350-450 (max) eleven. Na 65 163 100-300 (max) 12. Ca 18 36 100-200 (max) 13. Na+Ca 83 199 200 (max) 14. Fe 42 48 200-600 (max)

Table 12: Coke produced from mixture A and OLM

The calcined coke described in Example 3 was subjected to X-ray diffraction analysis to measure crystallite size (CS). The obtained LC value was ~38 Å, which indicates an improvement in the quality of the coke.

Advantages of the present invention:

1. The use of hydrogen is not required, since the technological method does not provide for hydrotreatment of oil residues.

2. Deasphalting with a solvent is not required, and therefore the technological method becomes more economical due to the absence of additional costs for solvents.

3. The present invention can be easily implemented using existing and widely available installations.

4. The separation of the lighter fraction (with a boiling point of less than 300°C) of the OLM in the preseparator is provided, which makes it possible to recover valuable lighter fractions in the production of anode coke.

5. Production of high quality coke that meets the requirements for anode coke.

Claims (37)

1. A method for producing anode coke in a delayed coking unit (DCU), which includes: i. loading hydrocarbon feedstock (1; 32) into a desalting unit (2; 33) to obtain a desalted crude oil stream (3; 34); ii. redirection of the desalted stream (3; 34) to the preseparator chamber (4; 35) to obtain a stream of lighter fractions (5; 36) with a boiling point < 300°C and a stream of heavier fractions with a boiling point > 300°C; iii. direction of flow of heavier fractions into the furnace (8; 39); iv. feeding the heated stream (9; 40) leaving the furnace (8; 39) into coke drums (12/13; 43/44) to produce lighter hydrocarbons and coke by cracking; v. the direction of the flow leaving the drums (16; 47) into the main fractionating unit (17; 49) to produce light coking gas oil, heavy coking gas oil, petroleum fuel; vi. mixing the stream of gaseous products (18; 50) from the main fractionation unit (17; 49) with the stream of lighter fractions (5; 36) with a boiling point < 300°C; vii. transferring the crude petroleum coke (25; 57) obtained from the coke drum to a feed hopper (26; 58) and receiving a feed stream for calcination (27; 59); And viii. calcination of crude petroleum coke (27; 59) in a furnace (28; 60) and transfer of calcined coke (29; 61) to a cooling unit (30; 62) to obtain anode coke (31; 63). 2. The method according to claim 1, in which the hydrocarbon feedstock (1; 32) is selected from a group of feedstocks consisting of various types of crude oil: sour oil, sweet oil, cheap grades of crude oil and streams of heavier fractions obtained from them. 3. The method according to claim 1, wherein the desalted stream (3) together with the high aromatic residue stream (6) is added to the pre-separator chamber (4) in step (ii) to ensure recovery of the valuable lighter boiling fraction with a lower boiling point 300°C and improve coke quality. 4. The method according to claim 1, in which coke drums (12, 13; 43, 44) are used at a temperature of 430-460°C in the upper part and a pressure of 1-5 kg/cm ² (g). 5. The method according to claim 1, in which the temperature of the heated stream (9; 40) coming from the furnace (8; 39) is in the range from 480°C to 510°C. 6. The method according to claim 3, in which the stream with a high content of aromatic residues (6) is selected from the group of substances including pyrolysis tar, high-temperature tar, clarified light oil. 7. The method according to claim 1, wherein the stream of heavier fractions with a boiling point > 300°C obtained in step (ii) is mixed with the return stream (38) before it is redirected to the furnace (39). 8. The method of claim 7, wherein the effluent stream from the coke drum (47) in the main fractionation unit (49) is mixed with the high aromatic residue stream (48) to condense heavier molecules from the effluent stream from the coke drum (47), and to obtain return flow (38). 9. The method according to claim 8, in which the stream with a high content of aromatic residues (48) is selected from the group of substances including pyrolysis tar, high temperature tar, clarified light oil. 10. The method according to claim 1, in which the content of sulfur and nitrogen in the resulting coke is ≤ 3% wt. and 0.1 wt.%, respectively, and the coke corresponds to the quality specified for anode coke. 11. A method for producing anode coke in a delayed coking unit (DCU) according to claim 1, which includes: i. loading hydrocarbon feedstock (1) into a desalting unit (2) to obtain a desalted crude oil stream (3); ii. redirection of the desalted stream (3) to the preseparator chamber (4) to obtain a stream of lighter fractions (5) with a boiling point < 300°C and a stream of heavier fractions with a boiling point > 300°C; iii. directing clarified light oil with a high content of aromatic oil residues (6) to the lower part of the preseparator chamber (4) to separate the fraction with a boiling point less than 300°C from the clarified light oil and mix with the flow of heavier fractions; iv. directing a mixed fraction stream (7), consisting of heavier fractions from crude oil and a stream of clarified light oil (6), into a furnace (8) for heating to cracking temperature; v. feeding the heated stream (9) leaving the furnace (8) into coke drums (12/13) to produce lighter hydrocarbons and coke by cracking; vi. the direction of the flow leaving the drum (16) into the main fractionating unit (17) to produce light coking gas oil (20), heavy coking gas oil (21), petroleum fuel (22); vii. mixing the stream of gaseous products (18) from the main fractionation unit (17) with the stream of lighter fractions (5) with a boiling point < 300°C; viii. transferring the crude petroleum coke (25) obtained from the coke drum to a feed hopper (26) and receiving a calcination feed stream (27); And ix. calcination of raw petroleum coke (27) in a furnace (28) and transfer of the calcined coke (29) to a cooling unit (30) to obtain anode coke (31). 12. A method for producing anode coke in a delayed coking unit (DCU) according to claim 1, which includes: i. loading hydrocarbon feedstock (32) into a desalting unit (33) to produce a desalted crude oil stream (34); ii. redirection of the desalted stream (34) to the preseparator chamber (35) to obtain a stream of lighter fractions (36) with a boiling point < 300°C and a stream of heavier fractions with a boiling point > 300°C; iii. adding the recycle stream (38) to the heavy ends stream (37) and sending them to a furnace (39) for heating to cracking temperature; iv. feeding the heated stream leaving the furnace (39) into coke drums (43/44) to produce lighter hydrocarbons and coke by cracking; v. direction of the flow leaving the drum (47), which is washed with a stream with a high content of aromatic oil residues (48), into the main fractionation unit (49) to obtain light coker gas oil (52), heavy coker gas oil (53), fuel oil (54 ) and for the condensation of heavier molecules to produce a return flow (38); vi. mixing a stream of gaseous products (50) from the main fractionation unit (49) with a stream of lighter fractions (36) with a boiling point < 300°C; And vii. transferring the crude petroleum coke (57) obtained from the coke drum to a feed hopper (58) and receiving a feed stream (59) for calcination; viii. calcination of crude petroleum coke (59) in a furnace (60) and transferring the calcined coke (61) to a cooling unit (62) to obtain anode coke (63).