CN-121991721-A - Preparation method and process system of isotropic coke

CN121991721ACN 121991721 ACN121991721 ACN 121991721ACN-121991721-A

Abstract

The invention provides a preparation method and a process system of isotropic coke, wherein the preparation method comprises the following steps of step 1, mixing crude oil with an oxidant, and then carrying out electric desalting treatment; and 2, performing atmospheric and vacuum distillation treatment on the mixture obtained in the step 1 to obtain vacuum residue fraction, and performing delayed coking treatment on the vacuum residue fraction to obtain isotropic coke. The method can efficiently utilize high-sulfur crude oil resources, plays roles in inhibiting ordered arrangement of components in the coking process by bringing high-sulfur compounds in raw materials into play and easily oxidizing to generate sulfones or sulfoxides, can not remain in coke, prepares high-performance like coke products, and improves comprehensive utilization rate and added value of raw materials.

Inventors

YU ZHIMIN
YANG XING
LU JINGMAN
GE SHAOHUI
LIU YINDONG
WANG LUHAI
CAO YUTING
SONG HAIPENG
LI SHENGPING
PANG WEIWEI

Assignees

中国石油天然气股份有限公司

Dates

Publication Date: 20260508
Application Date: 20241101

Claims (11)

1. The preparation method of the isotropic coke is characterized by comprising the following steps: step 1, mixing crude oil with an oxidant, and then performing electric desalting treatment; Step 2, performing atmospheric and vacuum distillation treatment on the mixture obtained in the step 1 to obtain vacuum residue fraction; and step 3, carrying out delayed coking treatment on the vacuum residue fraction to obtain isotropic coke.
2. The method for producing isotropic coke according to claim 1, wherein the electric field strength of the electric desalting treatment is 600-1200V/cm and the pressure is-0.1 to-0.2 Kpa, and the electric desalting treatment comprises at least two stages of electric desalting.
3. The method for producing isotropic coke according to claim 1, wherein the sulfur content in the crude oil is 2m% or more, the oxidizing agent is at least one of hydrogen peroxide, formic acid, acetic acid and biological acid, and the oxidizing agent accounts for 2-10m% of the crude oil by mass.
4. The method for preparing isotropic coke according to claim 1, wherein a demulsifier is further added in step 1, wherein the demulsifier is an oil-soluble demulsifier or a water-soluble demulsifier, and the demulsifier accounts for 10-80 μg/g of the crude oil in mass content.
5. The method for producing isotropic coke according to claim 1, wherein the cut point of the vacuum residuum fraction is controlled to be 420-520 ℃.
6. The method for preparing isotropic coke according to claim 1, wherein the condition of delayed coking is that the reaction temperature is 470-510 ℃, the reaction pressure is 0.1-0.6Mpa, and the reaction time is 24-48h.
7. A process system for preparing isotropic coke, comprising: The mixing device is used for mixing the crude oil and the oxidant; the electric desalting device is communicated with the mixing device, so that the mixture of the crude oil and the oxidant enters the electric desalting device for oxidation and desalting treatment; the atmospheric and vacuum distillation device is communicated with the electric desalting device, so that the oil phase in the electric desalting device enters the atmospheric and vacuum distillation device for atmospheric and vacuum distillation treatment; And the delayed coking device is communicated with the atmospheric and vacuum distillation device, so that the vacuum residue fraction obtained by cutting by the atmospheric and vacuum distillation device enters the delayed coking device for delayed coking treatment.
8. The process system for preparing isotropic coke according to claim 7, wherein said electric desalting means comprises at least two electric desalting tanks connected in series, and an oxidant replenishing inlet is provided on the electric desalting tank which is not directly connected with said mixing means.
9. The process system for preparing isotropic coke according to claim 8, wherein the electric desalting device comprises 3 electric desalting tanks which are sequentially connected in series, and the electric field strength of the electric desalting tanks is 600-1200 v/cm.
10. The process system for preparing isotropic coke according to claim 7, wherein the electro-desalting device is provided with a pressure control system to control the pressure in the electro-desalting device to be-0.1 to-0.2 Kpa.
11. The process system for preparing isotropic coke according to claim 9, wherein the electric desalting tank is provided with a pressure control system comprising a pressure monitoring mechanism, an exhaust mechanism and a safety valve, and when the pressure monitoring mechanism monitors that the pressure of the electric desalting device exceeds a set value, the electric desalting tank is stopped from feeding or the exhaust mechanism and the safety valve are started.

Description

Preparation method and process system of isotropic coke Technical Field The invention belongs to the field of new energy carbon materials, and particularly relates to a preparation method and a process system of isotropic coke. Background Currently, low sulfur crude oil (sulfur mass content is lower than 0.5%) accounts for 17%, sulfur crude oil (sulfur mass fraction is 0.5% -2.0%) accounts for 30.8%, high sulfur crude oil (sulfur mass fraction is more than 2%) accounts for 58%, and the trend of high sulfur content is further increased according to statistics. In 2011, the sulfur content of crude oil resources was 1.15%, which is expected to reach 1.33% by 2035. With the deterioration of crude oil resources, the existence of sulfur has various harm to petroleum processing process and product application thereof, such as corrosion of metal equipment, catalyst poisoning, environmental pollution in use process and the like. The delayed coking process has obvious advantages in processing inferior heavy oil, and the produced coke is used as an important raw material to play an important supporting role in preparing the carbon material. The properties of carbon products are largely dependent on the structure and properties of the aggregate, and isotropic coke plays a significant role in the carbon industry as does anisotropic coke in its unique properties. Isotropic coke generally refers to coke whose optical structure is a fine-particle mosaic structure, and has no single orientation, and this structure determines that the coke properties are the same in all directions, and exhibits macroscopic isotropy. Taking the thermal expansion coefficient property as an example, isotropic coke is uniform in all directions, unlike anisotropic coke such as needle coke, which is different in all directions so as to be lowest in the axial direction parallel to the needle texture. However, isotropic coke exhibits anisotropy on a micro-or nano-scale microscopic scale and can be graphitized to form graphite crystallites, while being macroscopically isotropic as a whole, so that the isotropic coke is very suitable as an aggregate of isotropic graphite. Research shows that in the process of manufacturing isotropic graphite, after asphalt binder and graphitization treatment are adopted, the distribution of microcrystals in the graphite is not oriented, so that the influence on the isotropy degree of the graphite is small, and if the isotropy degree of the coke particles is very good, the isotropy degree (also called an anisotropy coefficient) can be controlled within 1.1 even though compression molding is adopted. The general microscopic structures of the pitch coke and the petroleum coke are anisotropic, and in order to produce isotropic graphite by using the anisotropic coke, only complicated and lengthy production process flows can be adopted, while the isotropic graphite product produced by using the isotropic coke has great superiority, and the high strength, the high compactness and the unique isotropy of the isotropic graphite product lay a technical foundation for producing isotropic graphite, and the isotropic graphite product is particularly suitable for producing high-end special graphite, such as isotropic nuclear graphite and the like. CN202210134302.2 discloses a preparation method of isotropic coke for a lithium ion battery cathode material, which comprises the following steps of removing quinoline insoluble substances from aromatic-rich oil through vacuum flash evaporation to obtain flash evaporation oil, mixing the flash evaporation oil with a nucleating agent in proportion, carrying out a polymerization reaction, carrying out coking treatment on the polymerization oil, and then naturally cooling in a nitrogen atmosphere to obtain the isotropic coke. The nucleation agent is added, so that the mesophase spherule is easy to generate in the preparation process, fusion among the spherules is prevented by adding the nucleation agent, the number of the mesophase spherule is large, the distribution is uniform, meanwhile, the generation of a small-piece structure is promoted by the nucleation agent with the micron-sized, and isotropic coke is shown as a mosaic structure and a small-piece structure coexisting in microcosmic. However, the raw materials of the invention are limited to aromatic-rich oil, and the embedded structure can be formed only by the aid of the nucleating agent, so that new solid materials and injection systems are added. CN201310744125.0 discloses a preparation method of isotropic coke, coal tar is used as raw material, the coal tar is purified by solvothermal filtration, the obtained refined coal tar and resin are oxidized, crosslinked and condensed to obtain oxidized asphalt, and the oxidized asphalt is prepared into isotropic coke by delayed coking and calcination. The technology increases the crosslinking degree of the coal tar raw material through the oxidation crosslinking process with the resin, th