CN112745916A

CN112745916A - Method and equipment for preparing needle coke raw material

Info

Publication number: CN112745916A
Application number: CN201911050390.2A
Authority: CN
Inventors: 阎龙; 申海平; 刘自宾; 范启明
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: 2019-10-31
Filing date: 2019-10-31
Publication date: 2021-05-04
Anticipated expiration: 2039-10-31
Also published as: CN112745916B

Abstract

The invention relates to the field of needle coke raw material preparation, and particularly discloses a method and equipment for preparing a needle coke raw material, which comprises the following steps: carrying out condensation reaction on a raw material containing catalytic cracking slurry oil to enable colloid and asphaltene in the raw material to generate coke, so as to obtain a first gas component and a condensed oil material; carrying out buffer settling separation and filtration on the condensed oil to obtain base oil rich in coke powder, condensed and filtered oil slurry and a second gas component; fractionating the condensed and filtered oil slurry to obtain coking rich gas, coking gasoline, coking diesel oil and coking wax oil; separating the coking wax oil to obtain a wax oil light component rich in monocyclic aromatic hydrocarbon and bicyclic aromatic hydrocarbon and a wax oil heavy component rich in tricyclic aromatic hydrocarbon and tetracyclic aromatic hydrocarbon; and carrying out condensation reaction on the wax oil light component rich in the monocyclic aromatic hydrocarbon and the bicyclic aromatic hydrocarbon. The method of the invention can effectively utilize the catalytic cracking slurry oil, reduce the coke formation in the process, improve the quality of the needle coke raw material and increase the yield of the needle coke raw material.

Description

Method and equipment for preparing needle coke raw material

Technical Field

The invention relates to the field of preparation of needle coke raw materials, in particular to a method and equipment for preparing needle coke raw materials.

Background

The needle coke is a main raw material for producing high-power and ultrahigh-power graphite electrodes, and the high-quality needle coke has higher price and can be widely applied as ultrahigh-power graphite electrodes for electric furnace steelmaking, super capacitors for electric vehicles and lithium ion electrodes for communication batteries. The most critical influencing factor in needle coke production is the feedstock properties, the better the feedstock properties the higher the grade of needle coke product obtained. The raw material for producing needle coke generally requires that the aromatic hydrocarbon content is 30-50 wt%, the content of colloid and asphaltene is less than 1 wt%, the ash content is less than 100 mu g/g, and the sulfur content is less than 0.5 wt%, and particularly, the aromatic hydrocarbon contains higher tricyclic and tetracyclic aromatic hydrocarbons. The catalytic cracking slurry oil is rich in a large amount of aromatic hydrocarbon components, is an excellent component for producing needle coke, but also contains part of easily polymerized colloid, asphaltene, catalyst powder, heavy metal, sulfur and other impurities, and the components and the impurities can seriously influence the preparation process of the needle coke, so that the quality of the produced needle coke is reduced, and even the needle coke cannot be generated. The catalytically cracked oil slurry thus obtained is ideal as a needle coke feedstock if the above components and impurities are separated.

At present, the catalytic cracking slurry oil is mainly used for blending fuel oil or blending slag reduction as a raw material for delayed coking, and a large amount of aromatic hydrocarbon components become fuel oil components and common coke in the process, which is undoubtedly great waste. Delayed coking is a deep thermal cracking thermal processing technology, raw materials can simultaneously generate two different types of reactions of cracking and polycondensation, and the delayed coking is one of the main processing technologies of heavy oil, particularly poor heavy oil at present. The main reactor of delayed coking is the coke drum, in which the raw material is converted into an oil-gas mixture and coke, and in the traditional delayed coking process, a large amount of aromatic hydrocarbon components are converted into coke before leaving the coke drum, which reduces the yield of the needle coke raw material.

CN101724420A discloses a method for producing needle coke raw material by treating catalytic cracking slurry oil and conventional coking raw material by delayed coking process. In the method, oil slurry is fed from the middle upper part of a coke tower, conventional coking raw materials are fed from the bottom of the coke tower, the oil slurry is contacted with high-temperature oil gas in the coke tower, components which are not beneficial to needle coke production are removed, and coking wax oil is obtained through the side line of a coking fractionating tower and is used as a needle coke raw material. However, in the method, the oil slurry does not pass through the radiation section of the heating furnace, the temperature is low, the oil slurry is completely fed from the middle upper part, and the retention time is short, so that part of colloid and asphaltene can not be fully reacted and can be carried into the coking wax oil by oil gas, thereby influencing the quality of the obtained needle coke raw material; moreover, if the sulfur content in the catalytic cracking slurry oil is high, the sulfur content in the obtained coker gas oil is difficult to meet the requirement, so that the application of the method is limited considerably.

Disclosure of Invention

The present invention is directed to overcoming the above-mentioned drawbacks of the prior art and providing a method and apparatus for producing needle coke feedstock, which can effectively utilize catalytic cracking slurry oil, reduce coke formation during the process, improve the quality of the needle coke feedstock and increase the yield of the needle coke feedstock.

In order to achieve the above object, the present invention provides a method for producing a needle coke raw material, comprising: (1) carrying out condensation reaction on a raw material containing catalytic cracking slurry oil to enable colloid and asphaltene in the raw material to generate coke, so as to obtain a first gas component and a condensed oil material;

(2) carrying out buffer settling separation and filtration on the condensed oil to obtain base oil rich in coke powder, condensed and filtered oil slurry and a second gas component;

(3) fractionating the condensed and filtered oil slurry to obtain coking rich gas, coking gasoline, coking diesel oil and coking wax oil;

(4) separating the coking wax oil to obtain a wax oil light component rich in monocyclic aromatic hydrocarbon and bicyclic aromatic hydrocarbon and a wax oil heavy component rich in tricyclic aromatic hydrocarbon and tetracyclic aromatic hydrocarbon;

(5) and carrying out condensation reaction on the wax oil light component rich in the monocyclic aromatic hydrocarbon and the bicyclic aromatic hydrocarbon to obtain a liquid phase component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon.

Preferably, the method further comprises: before the step (1), the raw material containing the catalytic cracking slurry oil is heated to 450-515 ℃, preferably to 450-500 ℃.

Preferably, the sulfur content of the feedstock containing catalytic cracking slurry oil is 0.7 wt% or less, preferably 0.1 to 0.6 wt%, and more preferably 0.4 to 0.5 wt%.

Preferably, the conditions for buffering sedimentation in step (2) comprise: the temperature of the settling tank is 410-440 ℃; the pressure of the top of the tank is 0.14-0.30 MPa.

Preferably, in the step (3), the coker gas oil is distillate oil with a distillation range of 350-450 ℃.

Preferably, the conditions for fractionating in step (3) include: the temperature of the top of the fractionating tower is 100-145 ℃, the pressure of the top of the fractionating tower is 0.13-0.17MPa, and the temperature of the bottom of the fractionating tower is 310-360 ℃.

Preferably, in the step (4), the separation mode is extraction separation or stripping separation.

Preferably, the conditions of the stripping separation include: the pressure is 0.1-0.15MPa, the temperature is 300-330 ℃, and the weight ratio of the injected steam quantity to the coking wax oil is 0.05-0.1: 1.

Preferably, in step (1), the condensation reaction conditions include: the temperature is 350-600 ℃, preferably 400-470 ℃; the pressure is 0.12-6MPa, preferably 1-3 MPa.

Preferably, in step (5), the condensation reaction conditions include: the temperature is 350-600 ℃, preferably 400-490 ℃; the pressure is 0.12-6MPa, preferably 1.5-4 MPa.

Preferably, the condensation reaction in step (5) is carried out in the presence of a catalyst comprising an active component containing at least one of iron, copper and nickel and a support containing at least one of alumina and a molecular sieve, and the content of the active component on an elemental basis is from 5 to 35% by weight and the content of the support is from 65 to 95% by weight, based on the weight of the catalyst.

Preferably, the method further comprises: mixing the wax oil heavy component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon obtained in the step (4) and the liquid phase component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon obtained in the step (5) and recycling the mixture to be used as a needle coke raw material; and/or the method further comprises:

mixing the first gas component and the second gas component with the condensed and filtered slurry oil, and then carrying out the fractionation in the step (3);

and/or, before step (2), the method comprises:

heating the raw material containing the catalytic cracking slurry oil to 450-515 ℃, preferably to 450-500 ℃ to perform a first condensation reaction to obtain first condensation bottom oil and first condensation gas; the first condensation bottom oil part is circulated to prevent condensation products from depositing at the bottom of the reactor; the other part is returned and heated to the temperature of 450-510 ℃, preferably to the temperature of 450-490 ℃ for a second condensation reaction to obtain a second condensation bottom oil and a second condensation gas, and the first condensation gas and the second condensation gas are combined to be used as the first gas component; and (3) taking part of the second condensed bottom oil as the oil after condensation in the step (2), and circulating the other part at the bottom of the reactor to prevent coke from depositing at the bottom of the reactor.

The invention provides equipment for preparing needle coke raw materials, which comprises a first condensation unit, a sedimentation unit, a fractionation unit, a wax oil component separation unit and a second condensation unit;

the first condensation unit is used for carrying out condensation reaction on the raw material containing the catalytic cracking slurry oil to enable the colloid and the asphaltene in the raw material to generate coke, and a first gas component and a condensed oil material are respectively obtained at an outlet;

the settling unit is used for carrying out buffering settling separation on the condensed oil, and the outlet respectively obtains bottom oil rich in coke powder, condensed and filtered oil slurry and a second gas component;

the fractionating unit is used for fractionating the condensed and filtered oil slurry, and the outlet of the fractionating unit respectively obtains coking rich gas, coking gasoline, coking diesel oil and coking wax oil;

the wax oil component separation unit is used for separating the coking wax oil, and wax oil light components rich in monocyclic aromatic hydrocarbon and bicyclic aromatic hydrocarbon and wax oil heavy components rich in tricyclic aromatic hydrocarbon and tetracyclic aromatic hydrocarbon are respectively obtained at an outlet;

a second condensation unit; the condensation reaction is carried out on the wax oil light component rich in the monocyclic aromatic hydrocarbon and the bicyclic aromatic hydrocarbon, and liquid phase components rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon are respectively obtained at an outlet.

Preferably, the apparatus further comprises: and the heating furnace is used for preheating the raw materials before entering the first condensation unit.

Preferably, the first condensation unit comprises a first condensation reactor and a second condensation reactor, each comprising: the device comprises a raw material inlet arranged on the side wall, a gas outlet arranged at the top, a condensed oil outlet arranged on the side wall, a bottom circulating oil outlet and a bottom circulating oil inlet.

Preferably, the apparatus further comprises: the heating furnace is used for preheating a condensation raw material entering the first condensation unit, raw material inlets of the first condensation reactor and the second condensation reactor are communicated with the heater, a condensation oil outlet of the first condensation reactor is communicated with the heater, and a condensation oil outlet of the second condensation reactor is communicated with a feeding hole of the sedimentation unit.

Preferably, the settling unit is a buffer settling tank, and the buffer settling tank comprises an oil inlet arranged on the side wall, a bottom oil outlet rich in coke powder at the bottom, an oil slurry outlet after condensation and filtration of the side wall, a second gas component outlet at the top and an inlet for circulation of the bottom oil rich in coke powder at the side wall; and/or

The fractionating unit is an extraction device or a stripping tower, preferably a stripping tower, the stripping tower comprises a raw material inlet arranged on the side wall, a coking rich gas outlet at the top, a coking gasoline outlet on the side wall, a coking diesel oil outlet on the side wall, a coking wax oil outlet on the side wall, a bottom oil outlet at the bottom and a bottom oil circulating inlet on the side wall, the coking wax oil outlet is communicated with a feed inlet of the wax oil component separation unit, the bottom oil outlet at the bottom is communicated with an oil inlet for buffering and settling, and the bottom oil outlet at the bottom is communicated with the bottom oil circulating inlet on the side wall; and/or

The wax oil component separation unit comprises a feed inlet, a top gas outlet and a bottom raw material outlet; and/or

The second condensation unit comprises a condensation reactor comprising a sidewall feed inlet and a bottom reaction mass outlet.

Preferably, the stripping tower comprises a spraying unit, wherein the spraying unit is arranged above the raw material inlet and is used for washing the raw material by the circulating bottom oil entering through the bottom oil circulating inlet.

The method of the invention can effectively utilize the catalytic cracking slurry oil, reduce the coke formation in the process, improve the quality of the needle coke raw material and increase the yield of the needle coke raw material. Specifically, colloid and asphaltene in the catalytic cracking slurry oil are removed in the form of produced distillate oil and coke through a series of cracking reactions and condensation reactions, and metal impurities in the catalytic cracking slurry oil are also removed as components of the coke. Moreover, in the method of the invention, the wax oil component obtained by fractionation is firstly separated into a wax oil light component rich in monocyclic and bicyclic aromatic hydrocarbons and a wax oil heavy component rich in tricyclic and tetracyclic aromatic hydrocarbons, then the wax oil light component is sent to a wax oil reactor for condensation reaction, aromatic hydrocarbons in the wax oil light component are subjected to condensation reaction under the action of a catalyst to improve the content of the tricyclic and tetracyclic aromatic hydrocarbons, so as to obtain a liquid phase component rich in tricyclic and tetracyclic aromatic hydrocarbons, and the obtained wax oil heavy component and the liquid phase component rich in tricyclic and tetracyclic aromatic hydrocarbons are needle coke raw materials, in order to further improve the quality of the needle coke raw materials, the wax oil heavy component and the liquid phase component rich in tricyclic and tetracyclic aromatic hydrocarbons can be mixed, the mixed material flow is used as the needle coke raw materials, and the concentration of the tricyclic aromatic hydrocarbons and tetracyclic aromatic hydrocarbons in the needle coke raw materials can be improved (namely the quality is improved) through the treatment, and the sulfur content of the needle coke raw material is low.

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

Drawings

FIG. 1 is a schematic flow diagram of a process for producing needle coke feedstock in accordance with one embodiment of the present invention.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In order to fully react the colloid and the asphaltene, preferably, the method further comprises: before the step (1), the raw material containing the catalytic cracking slurry oil is heated to 450-515 ℃, preferably to 450-500 ℃.

In the method of the present invention, the raw materials may be fed to the condensation reactor in a feeding manner of: the raw materials are fed separately from the bottom of the reactor, separately from the upper part of the reactor, or simultaneously from the upper part and the bottom of the reactor, preferably from the bottom of the reactor.

In the process of the present invention, the sulfur content of the raw material containing the catalytic cracking slurry oil is preferably 0.7% by weight or less, more preferably 0.1 to 0.6% by weight, and still more preferably 0.4 to 0.5% by weight. The catalytic cracking slurry oil having a sulfur content of 0.7 wt% or less may be a catalytic cracking slurry oil obtained from the bottom of a catalytic cracking fractionator. In addition, the aromatic content of the catalytically cracked slurry oil obtained from the bottom of the catalytic cracking fractionator is usually higher than 50 wt%.

In the method of the present invention, preferably, in the step (3), the coker gas oil is a distillate with a distillation range of 350-450 ℃.

In the method of the present invention, preferably, the conditions for buffering sedimentation in step (2) include: the temperature of the settling tank is 410-440 ℃; the pressure of the top of the tank is 0.14-0.30 MPa.

Preferably, the fractionation is carried out in a fractionation column under conditions comprising: the temperature of the top of the fractionating tower is 100-145 ℃, the pressure of the top of the fractionating tower is 0.13-0.17MPa, and the temperature of the bottom of the fractionating tower is 310-360 ℃. The fractionation tower feed can be separated into gas, gasoline, diesel oil, wax oil (i.e. wax oil component) and fractionation tower bottom oil by the aforementioned fractionation.

In the process of the present invention, in the step (4), the separation method is not particularly limited as long as the wax oil component can be separated into a wax oil light component rich in monocyclic and bicyclic aromatic hydrocarbons and a wax oil heavy component rich in tricyclic and tetracyclic aromatic hydrocarbons. In the invention, the light component of the wax oil rich in the monocyclic aromatic hydrocarbon and the bicyclic aromatic hydrocarbon contains the monocyclic aromatic hydrocarbon, the bicyclic aromatic hydrocarbon and the tricyclic aromatic hydrocarbon, but the monocyclic aromatic hydrocarbon and the bicyclic aromatic hydrocarbon are main components, so the light component of the wax oil is the wax oil component rich in the monocyclic aromatic hydrocarbon and the bicyclic aromatic hydrocarbon; the wax oil heavy component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon contains the tricyclic aromatic hydrocarbon, the tetracyclic aromatic hydrocarbon and the aromatic hydrocarbon larger than the tetracyclic aromatic hydrocarbon, but the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon are main components, so the wax oil heavy component is the wax oil component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon. Preferably, the separation is by extraction or stripping.

According to the invention, preferably, the stripping separation is carried out in a stripping column, the conditions of the stripping separation comprising: the pressure is 0.1-0.15MPa, the temperature is 300-330 ℃, and the weight ratio of the injected steam quantity to the wax oil component entering the stripping tower is (0.05-0.1): 1.

According to the present invention, preferably, in step (1), the condensation reaction conditions include: the temperature is 350-600 ℃, preferably 400-470 ℃; the pressure is 0.12-6MPa, preferably 1-3 MPa.

According to the present invention, preferably, in step (5), the condensation reaction conditions include: the temperature is 350-600 ℃, preferably 400-490 ℃; the pressure is 0.12-6MPa, preferably 1.5-4 MPa.

According to the present invention, preferably, the conditions of the condensation reaction of step (1) and step (5) further comprise: the mass ratio of the reactor bottom circulation flow to the feeding flow is more than 0.2:1, and the residence time of the reactor is 0.5-1.5h, and is further preferably 0.5-1 h.

In the present invention, the pressure means an absolute pressure.

According to the present invention, it is preferable that the condensation reaction in step (5) is carried out in the presence of a catalyst comprising an active component containing at least one of iron, copper and nickel (e.g., an active component such as iron, copper, nickel, iron-copper, iron-nickel, copper-nickel or iron-copper-nickel) and a carrier containing at least one of alumina and a molecular sieve (e.g., alumina carrier, molecular sieve or alumina-molecular sieve), and that the content of the active component in terms of element is 5 to 35% by weight and the content of the carrier is 65 to 95% by weight, based on the weight of the catalyst. When the active ingredient contains a plurality of components, the ratio between the aforementioned plurality of components is not particularly required, and may be any ratio as long as it can satisfy the total content of the active ingredient in terms of elements of 5 to 35% by weight; when the carrier contains a plurality of components, the ratio between the plurality of components is not particularly limited, and may be any ratio as long as the content of the carrier is from 65 to 95% by weight. The foregoing catalysts may be commercially available or prepared by themselves. The method for preparing the catalyst is not particularly limited, and various methods commonly used in the art may be used, and examples thereof include: the carrier is soaked in the solution of soluble salt of active component in the same volume, and the mixture is stoved and roasted.

In the method of the present invention, the heavy wax oil component obtained in step (4) and the liquid phase component rich in tricyclic and tetracyclic aromatics obtained in step (5) are needle coke raw materials, and the quality of the needle coke raw materials can be improved by mixing the heavy wax oil component with the liquid phase component rich in tricyclic and tetracyclic aromatics, and using the mixture stream as the needle coke raw materials, so that, in order to further improve the quality of the needle coke raw materials, the method of the present invention preferably further comprises: and (3) mixing the heavy component of the wax oil obtained in the step (4) and the liquid component obtained in the step (5).

According to the method of the present invention, preferably the method further comprises: and (3) mixing the first gas component and the second gas component with the condensed and filtered oil slurry, and then carrying out fractionation.

According to the method of the present invention, preferably the method further comprises:

heating the raw material containing the catalytic cracking slurry oil to 450-515 ℃, preferably to 450-500 ℃ to perform a first condensation reaction to obtain first condensation bottom oil and first condensation gas; the first condensation bottom oil part is recycled to carry out the first condensation reaction; the other part is returned and heated to the temperature of 450-510 ℃, preferably to the temperature of 450-490 ℃ for a second condensation reaction to obtain a second condensation bottom oil and a second condensation gas, and the first condensation gas and the second condensation gas are combined to be used as the first gas component; and (3) taking part of the second condensed bottom oil as the oil material after condensation in the step (2), and returning the other part of the second condensed bottom oil to perform a second condensation reaction.

According to the invention, in order to fully utilize various heat, the heat exchange of each raw material or discharged material can be realized through a pipeline or a heat exchanger, and the invention has no special requirement for the heat exchange, and is not described in detail herein.

The present invention is carried out according to the aforementioned process flow, and in a second aspect, the present invention provides an apparatus for producing a needle coke feedstock, the apparatus comprising two condensation units, a cracking unit, a fractionation unit, and a wax oil component separation unit.

The two condensation units respectively carry out condensation reaction on macromolecular aromatic hydrocarbons in the high aromatic hydrocarbon component from the catalytic slurry oil to generate coking reaction; and the other condensation unit is used for carrying out condensation reaction on the wax oil light component from the wax oil component separation unit to obtain a liquid phase component rich in tricyclic and tetracyclic aromatic hydrocarbons.

The fractionation unit is used for fractionating the oil-gas mixture from the cracking unit to obtain a wax oil component;

the wax oil component separation unit is used for separating the wax oil component from the fractionation unit into a wax oil light component rich in monocyclic and bicyclic aromatic hydrocarbons and a wax oil heavy component rich in tricyclic and tetracyclic aromatic hydrocarbons.

Specifically, the invention provides equipment for preparing needle coke raw materials, which comprises a first condensation unit, a sedimentation unit, a fractionation unit, a wax oil component separation unit and a second condensation unit;

According to the present invention, preferably, the apparatus further comprises: and the heating furnace is used for preheating the raw materials before entering the first condensation unit.

According to the present invention, preferably, the first condensation unit comprises a first condensation reactor and a second condensation reactor, each comprising: the device comprises a raw material inlet arranged on the side wall, a gas outlet arranged at the top, a condensed oil outlet arranged on the side wall, a bottom circulating oil outlet and a bottom circulating oil inlet.

According to the present invention, preferably, the apparatus further comprises: the heating furnace is used for preheating a condensation raw material entering the first condensation unit, raw material inlets of the first condensation reactor and the second condensation reactor are communicated with the heater, a condensation oil outlet of the first condensation reactor is communicated with the heater, and a condensation oil outlet of the second condensation reactor is communicated with a feeding hole of the sedimentation unit.

The fractionating unit is an extraction device or a stripping tower, preferably a stripping tower, the stripping tower comprises a raw material inlet arranged on the side wall, a coking rich gas outlet at the top, a coking gasoline outlet on the side wall, a coking diesel oil outlet on the side wall, a coking wax oil outlet on the side wall, a bottom oil outlet at the bottom and a bottom oil circulating inlet on the side wall, the coking wax oil outlet is communicated with a feed inlet of the wax oil component separation unit, the bottom oil outlet at the bottom is communicated with an oil inlet for buffering and settling, and the bottom oil outlet at the bottom is communicated with the bottom oil circulating inlet on the side wall;

the wax oil component separation unit comprises a feed inlet, a top gas outlet and a bottom raw material outlet;

According to the invention, the stripping tower preferably comprises a spraying unit which is arranged above the raw material inlet and is used for washing the raw material by the circulating bottom oil entering through the bottom oil circulating inlet.

In the apparatus of the present invention, specific structures of the heating furnace, the fractionating tower, the filter, the extraction device, the stripping tower and the condensation reactor are not particularly limited, and may be various heating furnaces, fractionating towers, filters, extraction devices, stripping towers and reactors commonly used in the art, which are well known to those skilled in the art, and thus, detailed descriptions thereof are omitted.

According to the invention, in order to fully utilize various heat, the inlets and outlets or the discharge ports of the raw materials can be in cross connection, and heat exchange is realized through pipelines or heat exchangers and the like.

In accordance with one embodiment of the present invention, as shown in FIG. 1, a process for producing needle coke feedstock is carried out using an apparatus consisting essentially of: a heating furnace 2, colloid and asphaltene condensation reactors 3 and 6, a settling buffer tank 11, a fractionating tower 14, a stripping tower 21 and a wax oil condensation reactor 24. Specifically, the process for producing needle coke feedstock may comprise: the method comprises the following steps of (1) feeding a raw material 1 into a heating furnace, heating the raw material by the heating furnace, feeding the raw material into a first condensation reactor 3, taking bottom oil 4 of the reactor as circulating oil of the condensation reactor 3, stirring the bottom of the reactor, pumping out the bottom oil 5 of the other part of the first condensation reactor, heating the bottom oil by the heating furnace again, feeding the bottom oil into a second condensation reactor, taking bottom oil 7 of the reactor as circulating oil of a reactor 6, stirring the bottom of the reactor, pumping out bottom oil 10 of the second reactor, feeding the bottom oil into a buffer settling tank 11, stirring the bottom oil of the buffer settling tank by the circulating oil, pumping out top oil gases 8 and 9 of the first condensation reactor and the second condensation reactor, top gas 12 of the settling buffer tank and bottom oil of the settling tank to be used as mixed feeding of a fractionating tower 14, and discharging the bottom; at the lower part of the fractionating tower, part of bottom oil 19 of the fractionating tower is extracted to be used as tower bottom washing oil, the tower bottom washing oil is dispersed by a spraying unit (20) to wash the oil gas fed into the fractionating tower in a washing mode, and the other part of the bottom oil is extracted and then sent to a settling buffer tank; obtaining coking rich gas 15, coking gasoline 16, coking diesel oil 17 and coking wax oil 18 through a fractionating tower; the coker gas oil 18 is used as a wax oil component and enters a stripping tower 21 to be stripped (steam is injected 22), a wax oil light component rich in one-ring and two-ring aromatic hydrocarbons is obtained at the top of the stripping tower 21, a stripping tower bottom material flow 23, namely a wax oil heavy component rich in three-ring and four-ring aromatic hydrocarbons, is obtained at the bottom of the stripping tower 21, the wax oil light component enters a wax oil reactor 24 to be subjected to condensation reaction, a wax oil reactor extract flow 25, namely a liquid phase component rich in three-ring and four-ring aromatic hydrocarbons is obtained, and the stripping tower bottom material flow 23 is mixed with the wax oil reactor extract flow 25 to obtain a needle coke raw material 26. In the present invention, coker gas oil 18 (i.e., the wax oil component) refers to the distillate having a distillation range of 350-450 ℃.

The present invention will be described in detail below by way of examples, but the present invention is not limited thereto. In each of the examples and comparative examples, unless otherwise specified, the methods used are those conventional in the art.

Example 1

This example illustrates the process of the present invention for producing a needle coke feedstock.

As shown in fig. 1, after heat exchange is sequentially carried out on catalytic cracking slurry oil 1 (relevant parameters are shown in table 1), coking gasoline 16, coking diesel oil 17, coking wax oil 18 and coking heavy wax oil 19 (heat exchange is not marked in fig. 1), the catalytic cracking slurry oil enters a heating furnace to be heated to 450 ℃, then the catalytic cracking slurry oil enters a first condensation reactor 3, the pressure at the top of the reactor is 1.5Mpa, the mass ratio of reactor bottom oil 4 to a feed stream is 0.3:1, the first condensation reactor bottom oil is extracted and then heated by the heating furnace again, the catalytic cracking slurry oil enters a second condensation reactor 6 after being heated to 460 ℃, the pressure at the top of the reactor is 1.5Mpa, the mass ratio of reactor bottom oil 7 to the feed stream is 0.3:1, the second reactor bottom oil is extracted and then enters a buffer settling tank 11, the temperature of the settling tank is 420 ℃, the pressure is 0.20Mpa, the first condensation reactor top oil gas 8, 9, the settling tank top gas 12 and the settling tank bottom oil are extracted and then used as mixed feed of a fractionating tower 14, separating in a fractionating tower (under the separation conditions that the top pressure of the fractionating tower is 0.15MPa, the bottom temperature of the fractionating tower is 332 ℃ and the top temperature of the fractionating tower is 126 ℃) to obtain coked rich gas 15, coked gasoline 16, coked diesel oil 17 and coked wax oil 18, feeding the coked wax oil 18 into a stripping tower 21 for stripping, feeding steam 22 injected into the stripping tower 21 and the coked wax oil 18 fed into the stripping tower 21 in a weight ratio of 0.05, at a temperature of 300 ℃ and at a pressure of 0.12MPa into a stripping tower, feeding a material flow at the top of the stripping tower 21, a material flow at the bottom of a settling tank and a material flow (not marked in figure 1) of a heating furnace into a wax oil reactor 24 after heat exchange, feeding the mixture into a catalyst (based on the weight of the catalyst, the catalyst comprises 10 weight percent of copper and 90 weight percent of alumina, and the preparation method comprises the steps of impregnating the alumina with a copper nitrate solution in an equal volume, drying the mixture at 120 ℃ for, roasting at 500 ℃ for 2h) to carry out condensation reaction at 450 ℃ and under 2.0 MPa; the combined stream of stripper bottoms stream 23 and wax oil reactor draw stream 25 is needle coke feedstock 26. The properties of the resulting needle coke feedstock are shown in table 2.

Comparative example 1

The process is carried out as in example 1 except that coker gas oil 18 is used directly as the needle coke feedstock without a stripper 21 and a wax oil reactor 24, the properties of which are shown in Table 2.

Example 2

The procedure is as in example 1, except that:

the materials are heated to 455 ℃ before entering the first condensation reactor, and the top pressure of the first condensation reactor is 1.8 MPa;

the materials are heated to 465 ℃ before entering the first condensation reactor, and the top pressure of the second condensation reactor is 1.8 MPa;

the ratio of the weight of steam 22 injected in stripper 21 to the weight of coker wax oil 18 entering stripper 21 is 0.1.

The properties of the resulting needle coke feedstock are shown in table 2.

TABLE 1

TABLE 2

It can be seen from the data in table 2 that the process of the present invention can effectively utilize the catalytic cracking slurry, reduce coke formation during the process, improve the quality of the needle coke feedstock and increase the yield of the needle coke feedstock.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. A process for producing needle coke feedstock, the process comprising:

(1) carrying out condensation reaction on a raw material containing catalytic cracking slurry oil to enable colloid and asphaltene in the raw material to generate coke, so as to obtain a first gas component and a condensed oil material;

2. The method of claim 1, wherein the method further comprises: before the step (1), the raw material containing the catalytic cracking slurry oil is heated to 450-515 ℃, preferably to 450-500 ℃.

3. The process according to claim 1 or 2, wherein the feedstock comprising catalytic cracking slurry oil has a sulphur content of 0.7 wt% or less, preferably of from 0.1 to 0.6 wt%, more preferably of from 0.4 to 0.5 wt%.

4. The method as claimed in claim 1 or 2, wherein in the step (3), the coker gas oil is distillate oil with distillation range of 350-450 ℃;

5. The method according to claim 1 or 2, wherein in the step (4), the separation mode is extraction separation or stripping separation;

6. The method of claim 1, wherein,

in the step (1), the condensation reaction conditions include: the temperature is 350-600 ℃, preferably 400-470 ℃; the pressure is 0.12-6MPa, preferably 1-3 MPa; and/or

In the step (5), the condensation reaction conditions include: the temperature is 350-600 ℃, preferably 400-490 ℃; the pressure is 0.12-6MPa, preferably 1.5-4 MPa; and/or

In the step (2), the conditions of the buffer sedimentation comprise: the temperature of the settling tank is 410-440 ℃; the pressure of the top of the tank is 0.14-0.30 MPa.

7. The process according to claim 1 or 6, wherein the condensation reaction in step (5) is carried out in the presence of a catalyst comprising an active component containing at least one of iron, copper and nickel and a support containing at least one of alumina and a molecular sieve, and the content of the active component is 5 to 35% by weight in terms of element and the content of the support is 65 to 95% by weight in terms of the weight of the catalyst.

8. The method of claim 1 or 2, wherein the method further comprises: mixing the wax oil heavy component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon obtained in the step (4) and the liquid phase component rich in the tricyclic aromatic hydrocarbon and the tetracyclic aromatic hydrocarbon obtained in the step (5) and recycling the mixture to be used as a needle coke raw material; and/or the method further comprises:

and/or, before step (2), the method comprises:

9. An apparatus for preparing a needle coke raw material, comprising a first condensation unit, a settling unit, a fractionation unit, a wax oil component separation unit, and a second condensation unit;

10. The apparatus of claim 9, wherein the apparatus further comprises: and the heating furnace is used for preheating the raw materials before entering the first condensation unit.

11. The apparatus of claim 9, wherein the first condensation unit comprises a first condensation reactor and a second condensation reactor, each comprising: the device comprises a raw material inlet arranged on the side wall, a gas outlet arranged at the top, a condensed oil outlet arranged on the side wall, a bottom circulating oil outlet and a bottom circulating oil inlet.

12. The apparatus of claim 11, wherein the apparatus further comprises: the heating furnace is used for preheating a condensation raw material entering the first condensation unit, raw material inlets of the first condensation reactor and the second condensation reactor are communicated with the heater, a condensation oil outlet of the first condensation reactor is communicated with the heater, and a condensation oil outlet of the second condensation reactor is communicated with a feeding hole of the sedimentation unit.

13. The apparatus of any one of claims 9-12,

the settling unit is a buffering settling tank, and the buffering settling tank comprises an oil material inlet arranged on the side wall, a bottom oil outlet rich in coke powder at the bottom, an oil slurry outlet after condensation and filtration of the side wall, a second gas component outlet at the top and a bottom oil circulating inlet rich in coke powder at the side wall; and/or

14. The apparatus of claim 13, wherein the stripper comprises a spray unit disposed above the feedstock inlet for washing the feedstock with circulating bottoms entering through the bottoms circulation inlet.