A method for targeted polycondensation production of needle coke

Abstract

The present application relates to the technical field of needle coke, in particular to a method for producing needle coke by targeted polycondensation. The method is to divide the cylinder of the coke drum into a lower cylinder, a middle cylinder and an upper cylinder, and sequentially send needle coke raw materials into the bottom conical seal, the lower cylinder, the middle cylinder and the upper cylinder of the coke drum for reaction, and the density of the needle coke raw materials gradually increases in the direction from the bottom conical seal to the upper cylinder. The present application ensures the uniform internal structure of the needle coke product by sending needle coke raw materials with different densities into the coke drum, controlling the reaction temperature and pressure in different regions, significantly reducing the differences in various indicators, and thus improving the product quality.

Description

Technical Field

[0001] This invention relates to the field of needle coke technology, and more specifically to a method for producing needle coke by targeted polycondensation. Background Technology

[0002] Needle coke is a high-quality carbon material. It is a silver-gray solid with a metallic luster and distinct flow patterns. Its surface has large, relatively few elliptical pores, and the needle coke particles have a large aspect ratio, giving them a smooth feel. Needle coke is a common raw material for producing ultra-high power electrodes. Electrodes prepared from needle coke have advantages such as high power, good thermal shock resistance, high mechanical strength, and high allowable current density.

[0003] Depending on the raw materials, needle coke can be divided into two types: coal-based needle coke and petroleum-based needle coke. The main raw material for coal-based needle coke is coal tar pitch. Because it contains a certain amount of quinoline insolubles, these insolubles must be removed to prevent them from affecting the growth and coalescence of spherical crystals. Removal methods include distillation, centrifugation, solvent extraction, and modification. Solvent extraction and modification are commonly used industrial production methods. Petroleum-based needle coke is produced from petroleum refining products. Currently, its production is mainly based on delayed coking processes, which include three main stages: raw material pretreatment, delayed coking, and calcination.

[0004] Coking is a crucial stage in needle coke production. During this stage, the temperature of the pretreated needle coke feedstock rises rapidly before entering the coking tower where it undergoes cracking and condensation reactions. Coking conditions are a very important factor affecting the quality of needle coke. Studies have found that coking temperature and tower top pressure have a significant impact on the coking process, and many researchers have focused on optimizing coking process parameters. However, current needle coke production processes still suffer from uneven internal structure and significant differences in properties among needle coke products produced at different locations within the coking tower, which is highly detrimental to the promotion and application of needle coke products. Summary of the Invention

[0005] To address the technical problem of uneven structure and significant differences in indicators of coke products produced at different locations in a coking tower, this invention provides a method for targeted polycondensation production of needle coke. By introducing needle coke raw materials of different densities into the coking tower and controlling the reaction temperature and pressure in different areas, the internal structure of the needle coke product is ensured to be uniform, significantly reducing the differences in various indicators and thus improving product quality.

[0006] The technical solution of this invention is as follows:

[0007] A method for producing needle coke through targeted polycondensation involves dividing the coke tower into a lower cylinder, a middle cylinder, and an upper cylinder. Needle coke raw materials are sequentially fed into the bottom conical seal, the lower cylinder, the middle cylinder, and the upper cylinder for reaction. The density of the needle coke raw materials gradually increases from the bottom conical seal towards the upper cylinder.

[0008] Furthermore, the bottom conical seal has a density of 0.98-1.00 g / cm³. 3 The needle coke feedstock is fed for 3-5 hours, and the reaction temperature at the bottom conical seal is controlled at 460-470℃, and the reaction pressure is 0.55-0.60MPa.

[0009] Furthermore, the lower cylinder has a density of 1.02-1.04 g / cm³. 3 The needle coke feedstock is fed for 10-14 hours, and the reaction temperature of the lower cylinder is controlled at 470-480℃, and the reaction pressure is 0.55-0.60MPa.

[0010] Furthermore, the density of the middle cylinder is 1.04-1.06 g / cm³. 3 The needle coke feedstock is fed for 18-22 hours, and the reaction temperature in the middle cylinder is controlled at 480-490℃, with a reaction pressure of 0.50-0.55MPa.

[0011] Furthermore, the density of the upper cylinder is 1.06-1.08 g / cm³. 3 The needle coke feedstock is fed for 10-14 hours, and the reaction temperature of the upper cylinder is controlled at 490-500℃, and the reaction pressure is 0.45-0.50MPa.

[0012] Furthermore, raw materials of different densities are fed into the tower sequentially from the bottom inlet according to production time, and reacted in stages.

[0013] Furthermore, the raw material for needle coke is aromatic oil or a mixture of aromatic oil and refined pitch.

[0014] The beneficial effects of this invention are as follows:

[0015] The targeted polycondensation of this invention refers to the process of introducing needle coke raw materials of different densities into the bottom conical seal, lower cylinder, middle cylinder and upper cylinder of the coke tower, and controlling different reaction temperatures and pressures to obtain needle coke raw coke products with uniform internal structure and good index stability. The resulting products have low volatile matter and high strength. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0017] Example 1

[0018] Aromatic oil-rich needle coke feedstock of varying densities is introduced into different locations within a coking tower. By controlling different reaction temperatures and pressures, a needle coke raw coke product with a uniform internal structure is obtained. This needle coke raw coke product can be used to prepare electrode negative electrodes. The specific method is as follows:

[0019] Phase 1: At the bottom conical sealing section, a density of 0.98 g / cm³ is introduced. 3 The needle coke feedstock was reacted at a temperature of 460℃ and a pressure of 0.55MPa for 4 hours.

[0020] Second stage: In the lower cylindrical section, switch to a density of 1.04 g / cm³. 3 The needle coke feedstock was reacted at a temperature of 480℃ and a pressure of 0.55MPa for 12 hours.

[0021] The third stage: In the middle section of the cylinder, the density is switched to 1.06 g / cm³. 3 The needle coke feedstock was reacted at a temperature of 490℃ and a pressure of 0.50MPa for 20 hours.

[0022] Fourth stage: In the upper cylindrical section, switch to a density of 1.08 g / cm³. 3 The needle coke feedstock was reacted at a temperature of 500℃ and a pressure of 0.45MPa for 12 hours.

[0023] Comparative Example 1

[0024] A coke with a density of 1.05 g / cm³ was introduced into all locations of the coke tower. 3 The needle coke feedstock is rich in aromatic oil, and the remaining processes and conditions are the same as in Example 1.

[0025] The needle coke products produced in Example 1 and Comparative Example 1 were tested, and the test results are as follows:

[0026] Table 1 Comparison of needle coke products produced in Example 1 and Comparative Example 1

[0027]

[0028] Example 2

[0029] Aromatic oil-rich needle coke feedstock of varying densities is introduced into different locations within a coking tower. By controlling different reaction temperatures and pressures, a needle coke raw coke product with a uniform internal structure is obtained. This needle coke raw coke product can be used to prepare electrode negative electrodes. The specific method is as follows:

[0030] Phase 1: At the bottom conical sealing section, a density of 1.00 g / cm³ is introduced. 3 The needle coke feedstock was reacted at a temperature of 470℃ and a pressure of 0.55MPa for 5 hours.

[0031] Second stage: In the lower cylindrical section, switch to a density of 1.02 g / cm³. 3 The needle coke feedstock was reacted at a temperature of 470℃ and a pressure of 0.55MPa for 11 hours.

[0032] Phase 3: In the middle section of the cylinder, switch to a density of 1.04 g / cm³. 3 The needle coke feedstock was reacted at a temperature of 480℃ and a pressure of 0.50MPa for 18 hours.

[0033] Fourth stage: In the upper cylindrical section, switch to a density of 1.06 g / cm³. 3 The needle coke feedstock was reacted at a temperature of 490℃ and a pressure of 0.45MPa for 14 hours.

[0034] Comparative Example 2

[0035] A coke with a density of 1.07 g / cm³ was introduced into all locations of the coke tower. 3 The needle coke feedstock is rich in aromatic oil, and the remaining processes and conditions are the same as in Example 2.

[0036] The needle coke products produced in Example 2 and Comparative Example 2 were tested, and the test results are as follows:

[0037] Table 2 Comparison of needle coke products produced in Example 2 and Comparative Example 2

[0038]

[0039] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A method for producing needle coke through targeted polycondensation, characterized in that, The coking tower is divided into a lower cylinder, a middle cylinder, and an upper cylinder. Needle coke raw materials are sequentially fed into the bottom conical seal, the lower cylinder, the middle cylinder, and the upper cylinder for reaction. The density of the needle coke raw materials gradually increases from the bottom conical seal to the upper cylinder. Feed a material with a density of 0.98-1.00 g / cm³ into the bottom conical seal. 3 For needle-shaped coke feedstock, the reaction temperature at the bottom conical seal is controlled at 460-470℃, and the reaction pressure is 0.55-0.60MPa. Feed a material with a density of 1.02-1.04 g / cm³ into the lower cylinder. 3 The needle coke feedstock is used, and the reaction temperature in the lower cylinder is controlled at 470-480℃, and the reaction pressure is 0.55-0.60MPa. A feed material with a density of 1.04-1.06 g / cm³ is fed into the middle cylinder. 3 The needle coke feedstock is used to control the reaction temperature in the middle cylinder at 480-490℃ and the reaction pressure at 0.50-0.55MPa. Feed a solution with a density of 1.06-1.08 g / cm³ into the upper cylinder. 3 The needle coke feedstock is used, and the reaction temperature of the upper cylinder is controlled at 490-500℃, and the reaction pressure is 0.45-0.50MPa. Needle coke feedstocks of different densities enter the coke tower sequentially from the bottom feed inlet according to production time, and react in stages.

2. The method as described in claim 1, characterized in that, The feeding time for needle coke raw materials in the bottom conical seal is 3-5 hours, the feeding time for needle coke raw materials in the lower cylinder is 10-14 hours, the feeding time for needle coke raw materials in the middle cylinder is 18-22 hours, and the feeding time for needle coke raw materials in the upper cylinder is 10-14 hours.

3. The method as described in claim 1, characterized in that, Needle coke feedstock is aromatic oil or a mixture of aromatic oil and refined pitch.

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