CN109988630B

CN109988630B - Wax oil hydrogenation method and system

Info

Publication number: CN109988630B
Application number: CN201811627154.8A
Authority: CN
Inventors: 刘涛; 张学辉; 方向晨; 李宝忠; 彭绍忠; 王仲义
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2017-12-29
Filing date: 2018-12-28
Publication date: 2021-10-08
Anticipated expiration: 2038-12-28
Also published as: RU2708252C1; CN109988630A

Abstract

The invention relates to the field of petroleum refining, and discloses a wax oil hydrogenation method and a system, wherein the method comprises the following steps: (1) contacting wax oil raw oil and hydrogen-containing gas with a first hydrotreating catalyst, dividing the obtained first hydrotreating material flow into a first hydrotreating material flow a and a first hydrotreating material flow b, and carrying out gas-liquid separation on the first hydrotreating material flow a to obtain a first hydrotreating gas-phase material flow and a first hydrotreating liquid-phase material flow; (2) contacting the first hydrotreating material flow b, the first hydrotreating liquid-phase material flow and the hydrogen-containing gas with a second hydrotreating catalyst to obtain a hydrotreating product flow; (3) and contacting the first hydrogenation treatment gas phase material flow, the catalytic cracking light cycle oil and a hydrogenation refining catalyst for hydrogenation refining reaction to obtain a hydrogenation refining product material flow. The method and the system provided by the invention can produce high-quality catalytic cracking raw materials, and have flexible process and low energy consumption.

Description

Wax oil hydrogenation method and system

Technical Field

The invention relates to the field of petroleum refining, in particular to a wax oil hydrogenation method and system.

Background

Fluid Catalytic Cracking (FCC) is one of the important means for the conversion of heavy oil into light oil, but with the deterioration and the heavy conversion of the catalytic cracking processing raw material, the operation conditions are more and more strict, the yield of light products and the product properties are poor, and the hydrotreating technology of the catalytic cracking raw material can not only remove the contents of sulfur, nitrogen, metal and other impurities, but also improve the cracking performance of the feeding material, reduce the operation severity of FCC, improve the product distribution, improve the selectivity of target products, reduce the yield of dry gas and coke, improve the economy of an FCC device, reduce the sulfur content of the target products, reduce the SOx and NOx content in the regeneration flue gas, and the like. The catalytic cracking Light Cycle Oil (LCO) has a certain content of sulfur and nitrogen, both exist in the form of organic compounds, and has high content of aromatic hydrocarbons, especially the content of aromatic hydrocarbons with more than two rings, and usually, the catalytic cracking light cycle oil is directly circulated back to a catalytic cracking device for continuous conversion, or enters a hydrotreating device for hydrogenation and then enters the catalytic cracking device, or enters other devices for processing, or is directly used as a product.

CN103773495A, CN101875856A, CN102465035A, and CN1896192A disclose a process technology for blending catalytic cracking light cycle oil in a wax oil hydrotreating process, which mainly aims to produce high-quality catalytic cracking raw materials, or a coupling technology for circulating catalytic cracking light cycle oil between a wax oil hydrotreating device and a catalytic cracking device, so as to realize clean production of the catalytic cracking device.

In summary, compared with the existing catalytic cracking light cycle oil hydrogenation technology and wax oil hydrogenation technology, catalytic cracking light cycle oil is usually directly blended into a wax oil hydrogenation device for hydrogenation, and hydrogenated wax oil and hydrogenated catalytic cracking light cycle oil obtained after mixing hydrogenation are used as raw materials of the catalytic cracking device together, namely the catalytic cracking light cycle oil is hydrogenated and then returns to the catalytic cracking device.

Disclosure of Invention

In view of the defects of the prior art, the invention provides a wax oil hydrogenation method and system. The invention can produce high-quality catalytic cracking raw material by the combination process of hydrotreating and hydrofining the wax oil raw oil and the catalytic cracking light cycle oil, and has flexible process and low energy consumption.

In order to achieve the above object, a first aspect of the present invention provides a wax oil hydrogenation method, comprising the steps of:

(1) under a first hydrotreating condition, contacting wax oil raw oil and hydrogen-containing gas with a first hydrotreating catalyst to obtain a first hydrotreating material flow, dividing the first hydrotreating material flow into a first hydrotreating material flow a and a first hydrotreating material flow b, and performing gas-liquid separation on the first hydrotreating material flow a to obtain a first hydrotreating gas-phase material flow and a first hydrotreating liquid-phase material flow;

(2) under the second hydrotreating condition, contacting the first hydrotreating material flow b, the first hydrotreating liquid-phase material flow and the hydrogen-containing gas with a second hydrotreating catalyst to obtain a hydrotreating generated material flow;

(3) under the condition of hydrofining, the first hydrotreating gas phase material flow, the catalytic cracking light cycle oil and a hydrofining catalyst are contacted to carry out hydrofining reaction, and a hydrofining product material flow is obtained.

Preferably, the method further comprises cutting the catalytic cracking light cycle oil to obtain a light fraction and a heavy fraction, wherein the cutting temperature is 245-300 ℃; the step (3) comprises the following steps: under a first hydrofining condition, contacting a first hydrotreating gas phase material flow, a heavy fraction, hydrogen-containing gas and a first hydrofining catalyst to perform a first hydrofining reaction to obtain a first hydrofining material flow; and under second hydrofining conditions, contacting the first hydrofining material flow, the light fraction, the hydrogen-containing gas and a second hydrofining catalyst to perform a second hydrofining reaction. It is further preferred that the temperature of the second hydrofinishing reaction is lower than the temperature of the first hydrofinishing reaction, and it is still further preferred that the temperature of the second hydrofinishing reaction is 5 to 20 deg.C lower than the temperature of the first hydrofinishing reaction (more preferably 10 to 20 deg.C lower). By adopting the preferred embodiment, on the premise of meeting the requirement of sulfur content, the method is more beneficial to controlling the hydrogenation depth of the aromatic hydrocarbon to obtain more monocyclic aromatic hydrocarbon.

In a second aspect, the present invention provides a wax oil hydrogenation system, including:

a first hydroprocessing unit;

a gas-liquid separator for performing gas-liquid separation on a part of the first hydrotreated stream obtained by the first hydrotreating unit to obtain a first hydrotreated gas-phase stream and a first hydrotreated liquid-phase stream;

the rest part of the first hydrotreating material flow and the first hydrotreating liquid-phase material flow are subjected to second hydrotreating in the second hydrotreating unit to obtain a hydrotreating generated material flow;

a catalytically cracked light cycle oil supply unit for providing catalytically cracked light cycle oil;

and the catalytic cracking light cycle oil and the first hydrotreating gas phase material flow provided by the catalytic cracking light cycle oil supply unit are subjected to hydrofining in the hydrofining unit to obtain a hydrofined product flow.

Preferably, the hydrofining unit comprises a first hydrofining unit and a second hydrofining unit arranged in series; the system further comprises: the catalytic cracking light cycle oil fractionating tower is arranged between the first hydrofining unit and the catalytic cracking light cycle oil supply unit and is used for cutting the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit into light fractions and heavy fractions; hydrofining the heavy fraction and the first hydrotreated gas-phase stream in a first hydrofining unit to obtain a first hydrofined stream; and hydrofining the first hydrofined material flow and the light fraction in a second hydrofined unit to obtain the hydrofined product flow.

The requirements of product quality, environmental protection, process operation and the like all limit the properties of raw oil of a catalytic cracking unit, particularly the sulfur content, and the distribution and properties of catalytic cracking products are greatly different due to different raw oil compositions. In the research process, the inventor of the invention finds that the aromatic hydrocarbon hydrogenation saturation depth of the catalytic cracking light cycle oil has a large influence on the quality of the catalytic cracking gasoline product, particularly monocyclic aromatic hydrocarbon in the gasoline is a high-octane value component, and the octane value of the catalytic cracking gasoline can be increased by increasing the content of the monocyclic aromatic hydrocarbon in the catalytic cracking light cycle oil. The inventor of the present invention further researches and discovers that the content of monocyclic aromatic hydrocarbon in subsequent products can be increased by extracting a gas phase material flow from part of the first hydrotreating material flow, presumably because the extracted gas phase material flow contains hydrogen sulfide and ammonia with certain concentrations, the inhibition effect of the gas phase material flow is equivalent to the reduction of the activity of a catalyst, the hydrogenation depth of the catalytic cracking light cycle oil can be just controlled under the hydrofining condition, the bicyclic aromatic hydrocarbon and the polycyclic aromatic hydrocarbon in the catalytic cracking light cycle oil are hydrogenated to the monocyclic aromatic hydrocarbon on the premise of meeting the sulfur content requirement, but naphthenic hydrocarbon is not excessively generated by the hydrogenation depth, or the hydrogenation depth is insufficient to generate the bicyclic aromatic hydrocarbon, so that the content of aromatic hydrocarbon in the catalytic cracking gasoline can be increased when the hydrofined product enters the catalytic cracking device again, and the octane number of the catalytic cracking gasoline is increased. In addition, the process provided by the invention reduces the adverse effect of hydrogen sulfide and ammonia on the second hydrotreating catalyst, and is more favorable for prolonging the service life of the second hydrotreating catalyst.

Compared with the prior art, the wax oil hydrogenation method and the wax oil hydrogenation system have the advantages that:

1. in the invention, at least two steps of hydrotreatment are carried out, gas-liquid separation is carried out between the two steps of hydrotreatment, and a part of hydrotreatment gas-phase material is extracted, so that the effective distribution of a hydrotreatment material strand can be realized, and the obtained material is subjected to a hydrogenation combination process, so that target products with different specifications can be produced according to requirements. In the prior art, hydrofining technology and hydrotreating technology are used separately, so that only one target product of a hydrogenation process can be obtained.

2. The invention extracts the hydrotreating gas phase material flow of wax oil raw oil through hydrotreating by gas-liquid separation between two steps of hydrotreating, and sends the gas phase material flow and the catalytic cracking light cycle oil into a separately performed hydrofining reaction, because the extracted gas phase material flow contains hydrogen sulfide and ammonia, which is not beneficial to the hydrodesulfurization reaction of the catalytic cracking light cycle oil, the inhibiting effect is equivalent to reducing the activity of a catalyst, under the hydrofining condition, the hydrogenation depth of the catalytic cracking light cycle oil can be just controlled, the bicyclic aromatic hydrocarbon and the polycyclic aromatic hydrocarbon in the catalytic cracking light cycle oil are hydrogenated to monocyclic aromatic hydrocarbon on the premise of meeting the sulfur content requirement, but not the hydrogenation depth excessively generates naphthenic hydrocarbon or the hydrogenation depth is insufficient to generate bicyclic aromatic hydrocarbon, thus the content of the aromatic hydrocarbon in the catalytic cracking gasoline can be improved when the hydrofined product enters a catalytic cracking device again, thereby improving the octane number of the catalytic cracking gasoline; for the hydrotreating part, because the part of hydrogen sulfide and ammonia gas produced by hydrodesulfurization and hydrodenitrogenation reactions in the first hydrotreating process is extracted, the mixing of the residual material flow and the hydrogen-containing gas is equivalent to the reduction of the hydrogen sulfide partial pressure and the ammonia partial pressure in the second hydrotreating process, namely the reduction of the inhibition of the active center of the subsequent hydrotreating catalyst, or the improvement of the activity of the second hydrotreating catalyst and the reduction of the severity of the second hydrotreating operation.

3. In the invention, the gas phase material flow extracted between the two steps of hydrotreatment has high temperature and pressure, and can directly carry out single hydrofining reaction after being mixed with the catalytic cracking light cycle oil after heat exchange, thereby fully utilizing the heat carried by the part of hydrotreated gas phase material and realizing the coupling operation of hydrotreatment and hydrofining.

4. In the invention, the operation pressure of the hydrotreating reaction system and the hydrofining reaction system can be the same, and the hydrotreating reaction system and the hydrofining reaction system can share one set of separation and fractionation unit, thereby greatly saving the equipment investment and the operation cost.

Drawings

FIG. 1 is a schematic diagram of a wax oil hydrogenation system according to an embodiment of the invention provided in example 1;

FIG. 2 is a schematic diagram of a wax oil hydrogenation system according to an embodiment of the present invention provided in example 4;

FIG. 3 is a schematic diagram of a wax oil hydrogenation system according to an embodiment of the present invention, provided in example 5.

Description of the reference numerals

Detailed Description

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.

The first aspect of the invention provides a wax oil hydrogenation method, which comprises the following steps:

According to the invention, the initial distillation point of the wax oil raw oil is preferably 100-400 ℃, and the final distillation point is preferably 405-650 ℃. For example, the initial distillation point of the wax oil raw oil is 320-345 ℃, and the final distillation point is 550-620 ℃.

The wax oil raw material oil can be at least one selected from straight-run wax oil, coker wax oil, deasphalted oil, coal tar, coal direct liquefaction oil, coal indirect liquefaction oil, synthetic oil and shale oil.

The hydrogen-containing gas is a gas capable of providing hydrogen, and can be fresh hydrogen, circulating hydrogen or hydrogen-rich gas. The hydrogen-containing gas used in step (1) and step (2) of the present invention may be the same or different. The hydrogen-containing gas described in the present invention can be clearly understood by those skilled in the art after understanding the technical aspects of the present invention.

According to the present invention, the first hydrotreating catalyst and the second hydrotreating catalyst can be various hydrotreating catalysts conventionally used in the art, and preferably, the first hydrotreating catalyst and the second hydrotreating catalyst each independently contain a carrier and an active component, the active component is at least one of metal elements from group VIB and/or group VIII, and the carrier is alumina and/or silicon-containing alumina. The group VIB metal elements are generally Mo and/or W, and the group VIII metal elements are generally Co and/or Ni.

Preferably, the content of group VIB metal elements is from 10 to 35 wt% and the content of group VIII metal elements is from 3 to 15 wt%, calculated as oxides, based on the total amount of the first hydrotreating catalyst. Further preferably, the specific surface area of the first hydrotreating catalyst is 100-650m²The pore volume is 0.15-0.6 mL/g.

Preferably, the content of the group VIB metal element is 10 to 35 wt% and the content of the group VIII metal element is 3 to 15 wt% in terms of oxides, based on the total amount of the second hydrotreating catalyst. Further preferably, the specific surface area of the second hydrotreating catalyst is 100-650m²The pore volume is 0.15-0.6 mL/g.

The first hydrotreating catalyst and the second hydrotreating catalyst may be obtained commercially or may be prepared. The first hydrotreating catalyst and the second hydrotreating catalyst in the present invention each independently include, but are not limited to, 3936, 3996, FF-16, FF-24, FF-26, FF-36, FF-46, FF-56 hydrotreating catalyst, HC-K, HC-P catalyst of UOP company, TK-555, TK-565 catalyst of Topsoe company, KF-847, and KF-848 catalyst of Akzo company, which have been developed by the research and development institute of petrochemical engineering.

In the present invention, the first hydrotreating catalyst and the second hydrotreating catalyst may be the same or different.

The first and second hydrotreating conditions may employ conventional operating conditions, such as: the first and second hydroprocessing conditions each independently comprise: the reaction pressure is 3-19MPa, the reaction temperature is 300-450 ℃, and the liquid hourly space velocity is 0.2-6h^-1The volume ratio of hydrogen to oil is 100-: 1, preferably, the first and second hydrotreating conditions each independently comprise: the reaction pressure is 4-17MPa, the reaction temperature is 320-420 ℃, and the liquid hourly space velocity is 0.4-4h^-1The volume ratio of hydrogen to oil is 400-: 1, further preferably, the first and second hydrotreating conditions each independently comprise: the reaction pressure is 6-17MPa, the reaction temperature is 350-385 ℃, and the liquid hourly space velocity is 0.8-4h^-1The volume ratio of hydrogen to oil is 700-: 1. the first hydrotreating conditions and the second hydrotreating conditions may be the same or different.

According to the present invention, for better protection of the first hydrotreating catalyst, preferably, the method further comprises: firstly, the wax oil raw oil is contacted with a hydrogenation protective agent, and then is contacted with the first hydrotreating catalyst. This preferred embodiment is more advantageous in extending the useful life of the first hydroprocessing catalyst. Specifically, the hydroprotectant may be loaded in the upper portion of the first hydroprocessing catalyst bed. The hydrogenation protective agent is not particularly required by the invention, and can be various hydrogenation protective agents conventionally used in the field, such as FZC series catalysts developed by the comforting petrochemical research institute, including FZC-100, FZC-105 and FZC-106. In order to better exert the function of the hydrogenation protective agent, two or more hydrogenation protective agents can be used in a grading way. Those skilled in the art can make appropriate selections according to actual situations.

According to the invention, the operation conditions of the hydrogenation protective agent can adopt the conventional operation conditions, for example, the reaction pressure is 3-19MPa, the reaction temperature is 280-420 ℃, and the liquid hourly space velocity is 0.5-20h^-1The volume ratio of hydrogen to oil is 100-: 1.

according to a preferred embodiment of the present invention, the percentage of the first hydrotreated stream a to the total of the first hydrotreated stream a and the first hydrotreated stream b is in the range of 5 to 95 wt%, more preferably in the range of 10 to 80 wt%, and still more preferably in the range of 22 to 53 wt%.

According to the present invention, the first hydrotreated stream a is subjected to gas-liquid separation, and may be carried out in a gas-liquid separator. In the present invention, the conditions for the gas-liquid separation are not particularly limited, and the gas-liquid separation can be carried out according to a conventional technique in the art. The gas-liquid separator includes at least a reactant stream inlet, a liquid phase conduit, and a gas phase conduit. Specifically, the gas phase conduit pumps out the separated first hydrotreating gas phase material flow, and the liquid phase conduit guides the separated first hydrotreating liquid phase material flow to carry out the second hydrotreating reaction.

According to a preferred embodiment of the present invention, the first hydrotreating gas phase stream represents from 5 to 95% by volume, preferably from 10 to 80% by volume, and more preferably from 20 to 50% by volume of the hydrogen-containing gas in step (1).

According to the present invention, the catalytically cracked Light Cycle Oil (LCO) is not particularly limited, and may be various catalytically cracked light cycle oils conventionally used in the art, for example, the catalytically cracked light cycle oil has an initial boiling point of 100-. The catalytic cracking light cycle oil with the cut range of 156-380 ℃ is exemplified in the embodiment of the invention.

According to the method, the catalytic cracking light cycle oil can also contain at least one of coker diesel, ethylene cracking tar and coal tar. The specific implementation mode can appropriately broaden the sources of the diesel oil raw materials rich in the aromatic hydrocarbon.

According to the method, the weight ratio of the catalytic cracking light cycle oil to the wax oil raw oil is preferably 0.1-3: 1, more preferably 0.3 to 1.1: 1.

according to the present invention, the hydrorefining catalyst can be various hydrorefining catalysts conventionally used in the art, and preferably, the hydrorefining catalyst contains a carrier and an active component, wherein the active component is at least one of metal elements from group VIB and/or group VIII, and the carrier is alumina and/or siliceous alumina. The group VIB metal elements are generally Mo and/or W, and the group VIII metal elements are generally Co and/or Ni. Preferably, the content of the VIB group metal element is 10-35 wt% and the content of the VIII group metal element is 3-15 wt% calculated by oxide based on the total amount of the hydrofining catalyst. Further preferably, the specific surface area of the hydrorefining catalyst is 100-650m²The pore volume is 0.15-0.6 mL/g.

The hydrofinishing catalyst can be obtained commercially or by preparation. The hydrofining catalyst in the invention comprises 3936, FF-14, FF-16, FF-24, FF-26, FF-36, FF-56, FHUDS-5, FHUDS-7 catalyst, HC-K, HC-P catalyst of UOP company, TK-555 and TK-565 catalysts of Topsoe company, KF-847 and KF-848 catalysts of Akzo company, which are developed by the comforting petrochemical research institute.

According to the invention, the hydrofinishing conditions comprise: the reaction pressure can be 3-19MPa, the reaction temperature can be 260-450 ℃, and the liquid hourly space velocity can be 0.2-6h^-1The volume ratio of hydrogen to oil can be 100-: 1, preferably the reaction temperature is 280-410 ℃, and further preferably, the hydrofining conditions comprise: the reaction pressure is 4-17MPa, the reaction temperature is 300-400 ℃, and the liquid hourly space velocity is 0.5-5h^-1The volume ratio of hydrogen to oil is 300-: 1, more preferably, the reaction pressure is 6-17MPa, the reaction temperature is 340-375 ℃, and the liquid hourly space velocity is 1.5-5h^-1The volume ratio of hydrogen to oil is 1000-1500: 1.

according to a preferred embodiment of the present invention, the method further comprises cutting the catalytically cracked light cycle oil to obtain a light fraction and a heavy fraction, wherein the cutting temperature is 245-;

the step (3) comprises the following steps: under a first hydrofining condition, contacting a first hydrotreating gas phase material flow, a heavy fraction, hydrogen-containing gas and a first hydrofining catalyst to perform a first hydrofining reaction to obtain a first hydrofining material flow; and under second hydrofining conditions, contacting the first hydrofining material flow, the light fraction, the hydrogen-containing gas and a second hydrofining catalyst to perform a second hydrofining reaction.

Still more preferably, the temperature of the second hydrofinishing reaction is lower than the temperature of the first hydrofinishing reaction, preferably the temperature of the second hydrofinishing reaction is 5 to 20 ℃ lower than the temperature of the first hydrofinishing reaction, and more preferably the temperature of the second hydrofinishing reaction is 10 to 20 ℃ lower than the temperature of the first hydrofinishing reaction.

The heavy fraction obtained by cutting the raw oil of the catalytic cracking light cycle oil mainly contains polycyclic aromatic hydrocarbons, and the heavy fraction is subjected to two hydrofining reactions, so that the aim of controlling the hydrogenation depth of the aromatic hydrocarbons is better fulfilled, and the light fraction obtained by cutting the raw oil of the catalytic cracking light cycle oil is subjected to a few (once) hydrofining reactions so that the heavy fraction of the catalytic cracking light cycle oil and the bicyclic aromatic hydrocarbons are more favorable for simultaneously controlling the hydrogenation depth of the aromatic hydrocarbons, namely the hydrofined catalytic cracking light cycle oil meets the requirement of sulfur content, and simultaneously the bicyclic aromatic hydrocarbons and the polycyclic aromatic hydrocarbons are properly hydrogenated to monocyclic aromatic hydrocarbons, so that the catalytic cracking gasoline meeting the requirement of sulfur content can be obtained after further catalytic cracking, and the octane number of the gasoline can be improved.

In addition, according to the preferred embodiment of the present invention, the temperature of the second hydrofining reaction is 5 to 20 ℃ (more preferably 10 to 20 ℃) lower than that of the first hydrofining reaction, which is more favorable for the reaction of hydrogenation saturation conversion of bicyclic aromatic hydrocarbon into monocyclic aromatic hydrocarbon.

According to a preferred embodiment of the present invention, the first and second hydrofinishing conditions each independently comprise: the reaction pressure is 4-17MPa, the reaction temperature is 300-400 ℃, and the liquid hourly space velocity is 0.5-5h^-1The volume ratio of hydrogen to oil is 300-:1, preferably, the reaction pressure is 6-17MPa, the reaction temperature is 340-385 ℃, and the liquid hourly space velocity is 1.5-5h^-1The volume ratio of hydrogen to oil is 1000-1500: 1.

according to a preferred embodiment of the present invention, the temperature of the first hydrofining reaction is 340-395 deg.C, the temperature of the second hydrofining reaction is 320-385 deg.C, and more preferably, the temperature of the first hydrofining reaction is 355-375 deg.C, and the temperature of the second hydrofining reaction is 340-365 deg.C.

Further preferably, the liquid hourly volume space velocity of the first hydrofining reaction is 0.5-5h^-1(preferably 1-4 h)^-1More preferably 1.5 to 2.1 hours^-1) The liquid hourly volume space velocity of the second hydrofining reaction is 1-6h^-1(preferably 1.5-5 h)^-1More preferably 3.3 to 4.5 hours^-1）。

According to the invention, the first hydrogenation treatment in the step (1) and the second hydrogenation treatment in the step (2) can be carried out in one hydrogenation reactor or two hydrogenation reactors. Specifically, when the first hydrotreating in step (1) and the second hydrotreating in step (2) are performed in one hydrogenation reactor, a first hydrotreating catalyst bed and a second hydrotreating catalyst bed are sequentially disposed in the hydrogenation reactor, and a gas-liquid separator may be disposed between the first hydrotreating catalyst bed and the second hydrotreating catalyst bed to perform the gas-liquid separation. When the first hydrotreatment in the step (1) and the second hydrotreatment in the step (2) are performed in two hydrogenation reactors, the first hydrotreatment in the step (1) may be performed in a first hydrotreatment reactor, the second hydrotreatment in the step (2) may be performed in a second hydrotreatment reactor, the first hydrotreatment reactor and the second hydrotreatment reactor are arranged in series, and a gas-liquid separator may be arranged between the first hydrotreatment reactor and the second hydrotreatment reactor to perform the gas-liquid separation.

According to the invention, the hydrofining in the step (3) can be carried out in a hydrofining reactor, and a hydrofining catalyst bed layer is arranged in the hydrofining reactor. Further, preferably, the hydrofining reaction of step (3) includes a first hydrofining reaction and a second hydrofining reaction. The first and second hydrofining reactions may be performed in the same hydrogenation reactor or in two hydrogenation reactors. Specifically, when a first hydrofining reaction and a second hydrofining reaction are carried out in one hydrogenation reactor, a first hydrofining catalyst bed layer and a second hydrofining catalyst bed layer are sequentially arranged in the hydrogenation reactor. When the first hydrofining reaction and the second hydrofining reaction are performed in two hydrogenation reactors, the first hydrofining reaction may be performed in a first hydrofining reactor, and the second hydrofining reaction may be performed in a second hydrofining reactor, with the first hydrofining reactor and the second hydrofining reactor being arranged in series.

According to the method provided by the invention, a person skilled in the art can separate and fractionate the hydrotreating resultant stream obtained in the step (2) and the hydrofining resultant stream obtained in the step (3) according to specific needs to obtain specific target products.

According to the method provided by the present invention, preferably, the step (2) further comprises: separating and fractionating the hydrotreating generated material flow to obtain a hydrotreating hydrogen-rich gas, a hydrotreating gas, hydrotreating naphtha, hydrotreating diesel and hydrotreating heavy fraction; further preferably, the separation in the step (2) includes high-pressure separation and low-pressure separation, the hydrotreating generated material flow is subjected to high-pressure separation to obtain a hydrotreating hydrogen-rich gas and a hydrotreating high-pressure separation liquid-phase material flow, the hydrotreating high-pressure separation liquid-phase material flow is subjected to low-pressure separation to obtain a hydrotreating gas and a hydrotreating liquid-phase material flow, and the hydrotreating liquid-phase material flow is fractionated to obtain hydrotreating naphtha, hydrotreating diesel oil and hydrotreating heavy fraction. The high pressure separation may be performed in a high pressure separator and the low pressure separation may be performed in a low pressure separator. The conditions for the high-pressure separation and the low-pressure separation are not particularly limited in the present invention, and may be carried out according to the conventional techniques in the art.

Those skilled in the art can perform specific fractionation on the hydrotreating liquid phase stream according to specific needs of the product, the fractionation in step (2) of the present invention can be performed in a hydrotreating fractionation column, and the conditions of the fractionation in step (2) of the present invention are not particularly limited as long as the above product is obtained. For example, the various products described above may be obtained by fractionation, wherein the initial cut point of the hydrotreated naphtha may be 35 to 45 ℃, the cut temperature between the hydrotreated naphtha and the hydrotreated diesel may be 60 to 180 ℃, and the cut temperature between the hydrotreated diesel and the hydrotreated heavy fraction may be 330-375 ℃.

According to the method provided by the present invention, preferably, step (3) further comprises: separating and fractionating the hydrofining product flow to obtain hydrofining hydrogen-rich gas, hydrofining naphtha and hydrofining diesel; further preferably, the separation in the step (3) includes high-pressure separation and low-pressure separation, the hydrorefining resultant stream is subjected to high-pressure separation to obtain hydrorefining hydrogen-rich gas and hydrorefining high-pressure separation liquid-phase stream, the hydrorefining high-pressure separation liquid-phase stream is subjected to low-pressure separation to obtain hydrorefining gas and hydrorefining liquid-phase stream, and the hydrorefining liquid-phase stream is fractionated to obtain hydrorefining naphtha and hydrorefining diesel. The high pressure separation may be performed in a high pressure separator and the low pressure separation may be performed in a low pressure separator. The conditions for the high-pressure separation and the low-pressure separation are not particularly limited in the present invention, and may be carried out according to the conventional techniques in the art.

Those skilled in the art can perform specific fractionation on the hydrofinishing liquid phase stream according to specific needs of the product, the fractionation in step (3) of the present invention can be performed in a hydrofinishing fractionation tower, and the conditions for the fractionation in step (3) of the present invention are not particularly limited as long as the above product is obtained. For example, the above-mentioned various products can be obtained by fractionation, wherein the initial boiling point of the hydrotreated naphtha is 35 to 45 ℃ and the cutting temperature between the hydrotreated naphtha and the hydrotreated diesel is 60 to 180 ℃.

In the present invention, both the hydrotreating gas and the hydrofinishing gas are hydrocarbon-rich gases. And the gas can be separated according to actual requirements to obtain the required gas product.

According to a preferred embodiment of the invention, the method further comprises: recycling the hydrogen-rich gas from the hydrogenation treatment and the hydrogen-rich gas from the hydrogenation refining to provide the required hydrogen-containing gas. The hydrogen-rich gas after hydrotreating and the hydrogen-rich gas after hydrofining can be directly recycled, and can also be recycled after desulfurization.

The hydrogen-rich gas and the hydrogen-rich refined gas can be recycled to the step (1) and/or the step (2) independently, and when the hydrogen-rich gas and the hydrogen-rich refined gas are not enough to provide the hydrogen required by the method provided by the invention, supplementary hydrogen can be introduced. The recycling of the hydrogen-rich gas from the hydrotreating process and the hydrorefining process is well understood by those skilled in the art after understanding the technical solution of the present invention.

The hydrogen concentration in the hydrogen-rich gas after hydrotreating and hydrogen-rich gas after hydrofining is higher, and the hydrogen-containing gas obtained after mixing with the supplementary hydrogen is higher, and generally can reach 85-97 volume percent.

In order to further simplify the apparatus, it is preferable that the pressure of the resulting hydrotreated hydrogen-rich gas and the hydrofinished hydrogen-rich gas obtained by the high-pressure separation in step (1) and the high-pressure separation in step (2) be the same. With this preferred embodiment, the hydrogen-rich gas from hydrotreating and the hydrogen-rich gas from hydrofinishing can be recycled using a single system.

The hydrotreating gas obtained in the step (2) and the hydrofining gas obtained in the step (3) can be used as products independently or can be mixed to be a mixed gas product.

The hydrotreated naphtha obtained in the step (2) and the hydrotreated naphtha obtained in the step (3) may be used alone as a product, or may be mixed to a mixed naphtha product.

The hydrotreated diesel oil obtained in the step (2) and the hydrofined diesel oil obtained in the step (3) can be used as products independently or can be mixed into a mixed diesel oil product.

The hydrotreated heavy fraction obtained in the step (2) can be used as raw oil of a catalytic cracking unit.

According to the present invention, in order to further save the equipment investment and the operation cost, preferably, the method further comprises: and mixing the hydrotreating generated material flow and the hydrofining generated material flow to obtain a mixed material flow, then separating (preferably comprising high-pressure separation and low-pressure separation) and fractionating the mixed material flow, further preferably, performing high-pressure separation on the mixed material flow to obtain a mixed hydrogen-rich gas and a mixed high-pressure separated liquid phase material flow, performing low-pressure separation on the mixed high-pressure separated liquid phase material flow to obtain a mixed gas and a mixed liquid phase material flow, and fractionating the mixed liquid phase material flow to obtain mixed naphtha, mixed diesel oil and mixed heavy fraction. The high pressure separation may be performed in a high pressure separator and the low pressure separation may be performed in a low pressure separator. The conditions for the high-pressure separation and the low-pressure separation are not particularly limited in the present invention, and may be carried out according to the conventional techniques in the art.

The mixed liquid phase stream can be subjected to specific fractionation by those skilled in the art according to specific needs for the product, the fractionation can be carried out in a mixed fractionation column, and the conditions for the fractionation are not particularly limited in the present invention as long as the above product is obtained. For example, the initial boiling point of the mixed naphtha may be 35 to 45 ℃, the cut temperature between the mixed naphtha and the mixed diesel may be 60 to 180 ℃, and the cut temperature between the mixed diesel and the mixed heavy fraction may be 330 ℃ to 375 ℃.

The mixed gas is a hydrocarbon-rich gas. And the gas can be separated according to actual requirements to obtain the required gas product.

According to a preferred embodiment of the invention, the method further comprises: recycling the mixed hydrogen-rich gas to provide the required hydrogen-containing gas. The mixed hydrogen-rich gas can be directly recycled and can also be recycled after desulfurization.

In a second aspect, the present invention provides a wax oil hydrogenation system, as shown in fig. 1, 2 and 3, comprising:

a first hydroprocessing unit 1;

a gas-liquid separator 2, wherein the gas-liquid separator 2 is used for performing gas-liquid separation on a part of the first hydrotreating material flow obtained by the first hydrotreating unit 1 to obtain a first hydrotreating gas-phase material flow and a first hydrotreating liquid-phase material flow;

the second hydrotreating unit 3 is used for carrying out second hydrotreating on the rest part of the first hydrotreating material flow and the first hydrotreating liquid-phase material flow in the second hydrotreating unit 3 to obtain a hydrotreating generated material flow;

a catalytic cracking light cycle oil supply unit 4, the catalytic cracking light cycle oil supply unit 4 being configured to provide catalytic cracking light cycle oil;

and the hydrofining unit 5 is used for hydrofining the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit 4 and the first hydrotreating gas phase material flow in the hydrofining unit 5 to obtain a hydrofined product material flow.

In the present invention, the catalytically cracked light cycle oil supply unit 4 is not particularly limited as long as it can supply catalytically cracked light cycle oil, and may be a storage tank for catalytically cracked light cycle oil or an apparatus for producing catalytically cracked light cycle oil.

According to the present invention, the outlet of the catalytic cracking light cycle oil supply unit 4 is communicated with the inlet of the hydrofinishing unit 5 through a pipeline.

According to the system provided by the present invention, preferably, the gas-liquid separator 2 comprises a reactant stream inlet, a liquid phase conduit and a gas phase conduit; the reactant stream inlet of the gas-liquid separator 2 is communicated with the outlet of the first hydrotreating unit 1, the first hydrotreating liquid-phase stream is introduced into the second hydrotreating unit 3 through a liquid-phase conduit, and the first hydrotreating gas-phase stream is introduced into the hydrofining unit 5 through a gas-phase conduit. A part of the first hydrotreating material flow obtained by the first hydrotreating unit 1 is subjected to gas-liquid separation in a gas-liquid separator 2 to obtain a first hydrotreating gas-phase material flow and a first hydrotreating liquid-phase material flow; the first hydrotreating liquid stream is introduced into the second hydrotreating unit through a liquid conduit to be subjected to second hydrotreating with the remaining part of the first hydrotreating stream in the second hydrotreating unit 3, the first hydrotreating gas stream is introduced into the hydrofining unit 5 through a gas conduit, and is hydrofined with the catalytically cracked light cycle oil supplied from the catalytically cracked light cycle oil supply unit 4 in the hydrofining unit 5.

According to the system provided by the present invention, the arrangement of the first hydrotreating unit 1 and the second hydrotreating unit 3 is not particularly limited, and according to an embodiment of the present invention, the first hydrotreating unit 1 and the second hydrotreating unit 3 may be arranged in one hydrogenation reactor; according to another embodiment of the present invention, the first hydroprocessing unit 1 and the second hydroprocessing unit 3 may each be provided in a different hydrogenation reactor.

According to a preferred embodiment of the present invention, the hydrofinishing unit 5 comprises a first hydrofinishing unit 51 and a second hydrofinishing unit 52 arranged in series, the system further comprising: a catalytic cracking light cycle oil fractionating tower 12 disposed between the first hydrorefining unit 51 and the catalytic cracking light cycle oil supply unit 4, the catalytic cracking light cycle oil fractionating tower 12 being configured to cut the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit 4 into a light fraction and a heavy fraction; the heavy fraction and the first hydrotreated gas-phase stream are hydrotreated in a first hydrotreating unit 51 to obtain a first hydrotreated stream; the first hydrofinished stream and the light fraction are hydrofinished in a second hydrofinishing unit 52 to obtain the hydrofinished product stream.

Specifically, an inlet of the catalytic cracking light cycle oil fractionating tower 12 is communicated with an outlet of the catalytic cracking light cycle oil supply unit 4 through a pipeline, and the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit 4 enters the catalytic cracking light cycle oil fractionating tower 12 to be fractionated, so as to obtain a light fraction and a heavy fraction. The catalytic cracking light cycle oil fractionating tower 12 is provided with a light fraction outlet and a heavy fraction outlet, the heavy fraction outlet of the catalytic cracking light cycle oil fractionating tower 12 is communicated with the inlet of the first hydrofining unit 51, and the light fraction outlet of the catalytic cracking light cycle oil fractionating tower 12 is communicated with the inlet of the second hydrofining unit 52.

According to the present invention, the first hydrorefining unit 51 and the second hydrorefining unit 52 may be disposed in one hydrogenation reactor, or may be disposed in different hydrogenation reactors. Preferably, the first hydrorefining unit 51 and the second hydrorefining unit 52 are disposed in one hydrogenation reactor.

By adopting the preferred embodiment, the refined catalytic cracking light cycle oil can meet the requirement of sulfur content, meanwhile, the bicyclic aromatic hydrocarbon and the polycyclic aromatic hydrocarbon are properly hydrogenated to the monocyclic aromatic hydrocarbon, the catalytic cracking gasoline meeting the requirement of sulfur content can be obtained after further catalytic cracking, and the octane number of the gasoline can be improved.

According to the system provided by the present invention, a person skilled in the art can separate and fractionate the hydrotreating resultant stream obtained from the second hydrotreating unit 3 and the hydrofining resultant stream obtained from the hydrofining unit 5 according to specific needs to obtain specific target products.

According to one embodiment of the invention, the hydrotreating product stream and the hydrofinishing product stream are separated and fractionated, respectively.

According to the system provided by the present invention, preferably, the system further comprises:

a hydrotreating separation unit comprising a hydrotreating high-pressure separator 61 and a hydrotreating low-pressure separator 62 connected in series, wherein an outlet of the second hydrotreating unit 3 is communicated with an inlet of the hydrotreating high-pressure separator 61 through a pipeline; the hydrotreating generated material flow is subjected to high-pressure separation in a hydrotreating high-pressure separator 61 to obtain a hydrotreating hydrogen-rich gas and a hydrotreating high-pressure separated liquid-phase material flow, and the hydrotreating high-pressure separated liquid-phase material flow is subjected to low-pressure separation in a hydrotreating low-pressure separator 62 to obtain a hydrotreating gas and a hydrotreating liquid-phase material flow.

According to the system provided by the present invention, preferably, the system further comprises: and an inlet of the hydrotreating fractionating tower 7 is communicated with an outlet of the hydrotreating low-pressure separator 62 through a pipeline, and the hydrotreating liquid-phase material flow is fractionated in the hydrotreating fractionating tower 7 to obtain hydrotreating naphtha, hydrotreating diesel oil and hydrotreating heavy fraction.

According to the system provided by the present invention, preferably, the system further comprises: the hydrofining separation unit comprises a hydrofining high-pressure separator 81 and a hydrofining low-pressure separator 82 which are connected in series, and an outlet of the hydrofining unit 5 is communicated with an inlet of the hydrofining high-pressure separator 81 through a pipeline; the hydrorefining resultant stream is subjected to high-pressure separation in a hydrorefining high-pressure separator 81 to obtain a hydrorefining hydrogen-rich gas and a hydrorefining high-pressure separation liquid phase stream, and the hydrorefining high-pressure separation liquid phase stream is subjected to low-pressure separation in a hydrorefining low-pressure separator 82 to obtain a hydrorefining gas and a hydrorefining liquid phase stream.

According to the system provided by the present invention, preferably, the system further comprises: and an inlet of the hydrofining fractionating tower 9 is communicated with an outlet of the hydrofining low-pressure separator 82 through a pipeline, and the hydrofining liquid phase material flow is fractionated in the hydrofining fractionating tower 9 to obtain hydrofining naphtha and hydrofining diesel oil.

The hydrotreating high-pressure separator 61 and the hydrofinishing high-pressure separator 81 are not particularly limited in the present invention, and may be various high-pressure separators conventionally used in the art. Likewise, the hydrotreating low pressure separator 62 and the hydrofinishing low pressure separator 82 are not particularly limited in this invention and may be any of the various low pressure separators conventionally used in the art.

The hydrotreating fractionation column 7 of the present invention is not particularly limited as long as the above-mentioned product can be obtained by fractionation. The person skilled in the art can carry out a specific fractionation of the hydrotreating liquid stream according to specific needs for the product, and the product obtained by fractionating the hydrotreating liquid stream is as described above and will not be described herein again.

The hydrorefining fractionator 9 of the present invention is not particularly limited as long as the product can be obtained by fractionation. Those skilled in the art can perform specific fractionation on the hydrofinishing liquid phase stream according to specific needs of the product, and the product obtained by fractionating the hydrofinishing liquid phase stream is as described above and will not be described in detail herein.

According to a preferred embodiment of the present invention, the gas phase outlets of the hydrotreating high-pressure separator 61 and the hydrofining high-pressure separator 81 are respectively and independently communicated with the inlet of the first hydrotreating unit 1 and/or the inlet of the second hydrotreating unit 3, so that the hydrotreating hydrogen-rich gas and the hydrofining hydrogen-rich gas can be recycled to provide hydrogen required by the system. The specific utilization manner is as described above, and is not described herein again.

According to another embodiment of the present invention, the hydrotreating product stream and the hydrofinishing product stream are combined to provide a combined stream, which is then subjected to separation and fractionation. This embodiment is more advantageous in reducing equipment investment.

the mixed fractionation system comprises a mixed separation unit and a mixed fractionation tower 11, wherein the mixed separation unit comprises a mixed high-pressure separator 101 and a mixed low-pressure separator 102 which are connected in series, and an outlet of the mixed low-pressure separator 102 is communicated with an inlet of the mixed fractionation tower 11; the outlet of the second hydrotreating unit 3 and the outlet of the hydrofining unit 5 are communicated with the inlet of the mixing high-pressure separator 101; mixing the hydrotreating generated material flow and the hydrofining generated material flow, and then performing high-pressure separation in a mixed high-pressure separator 101 to obtain a mixed hydrogen-rich gas and a mixed high-pressure separation liquid-phase material flow;

the mixed high-pressure separated liquid phase material flow is subjected to low-pressure separation in a mixed low-pressure separator 102 to obtain mixed gas and a mixed liquid phase material flow;

the mixed liquid phase material flow is fractionated in a mixed fractionating tower 11, and mixed naphtha, mixed diesel oil and mixed heavy fraction are obtained.

The hybrid high-pressure separator 101 is not particularly limited in the present invention, and may be various high-pressure separators conventionally used in the art. Likewise, the hybrid low pressure separator 102 is not particularly limited in the present invention and may be any of various low pressure separators conventionally used in the art.

The mixed fractionator 7 of the present invention is not particularly limited as long as the product can be fractionated. The fractionation of the mixed liquid phase stream to obtain the product as described above can be performed by those skilled in the art according to the specific requirements for the product, and will not be described herein again.

According to a preferred embodiment of the present invention, the gas phase outlet of the hybrid high-pressure separator 101 is communicated with the inlet of the first hydroprocessing unit 1 and/or the inlet of the second hydroprocessing unit 3 to recycle the hybrid hydrogen-rich gas to provide hydrogen required by the system. The specific utilization manner is as described above, and is not described herein again.

Hereinafter, a wax oil hydrogenation method and system according to an embodiment of the present invention will be described in detail with reference to fig. 3.

(1) The wax oil raw oil and the hydrogen-containing gas enter a hydrotreating reactor, a first hydrotreating unit 1 (a first hydrotreating catalyst bed layer) and a second hydrotreating unit 3 (a second hydrotreating catalyst bed layer) are arranged in the hydrotreating reactor, and a gas-liquid separator 2 is arranged between the first hydrotreating unit 1 and the second hydrotreating unit 3. A part of the first hydrotreated stream (first hydrotreated stream a) passing through the first hydrotreating catalyst bed is subjected to gas-liquid separation in the gas-liquid separator 2 to obtain a first hydrotreated gas-phase stream and a first hydrotreated liquid-phase stream.

(2) The rest part of the first hydrotreating material flow (the first hydrotreating material flow b), the first hydrotreating liquid-phase material flow and the hydrogen-containing gas enter a second hydrotreating catalyst bed layer to obtain a hydrotreating generated material flow, the hydrotreating generated material flow enters a hydrotreating high-pressure separator 61 to be subjected to high-pressure separation to obtain a hydrotreating hydrogen-rich gas and a hydrotreating high-pressure separated liquid-phase material flow, and the hydrotreating high-pressure separated liquid-phase material flow enters a hydrotreating low-pressure separator 62 to be subjected to low-pressure separation to obtain a hydrotreating gas and a hydrotreating liquid-phase material flow; fractionating the hydrotreated liquid-phase material flow in a hydrotreating fractionating tower 7 to obtain hydrotreated naphtha, hydrotreated diesel and hydrotreated heavy fraction;

(3) the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit 4 is cut into light fraction and heavy fraction by the catalytic cracking light cycle oil fractionating tower 12, the heavy fraction and the first hydrotreating gas phase material flow obtained in the step (1) enter a hydrofining unit 5, and a first hydrofining unit 51 (a first hydrofining catalyst bed layer) and a second hydrofining unit 52 (a second hydrofining catalyst bed layer) are arranged in the hydrofining unit 5. And (2) passing the heavy fraction and the first hydrotreating gas-phase material flow obtained in the step (1) through a first hydrofining catalyst bed layer to obtain a first hydrofining material flow, and passing the first hydrofining material flow and the light fraction through a second hydrofining catalyst bed layer to obtain a hydrofining product flow. The hydrofining generated material flow enters a hydrofining high-pressure separator 81 for high-pressure separation to obtain a hydrofining hydrogen-rich gas and a hydrofining high-pressure separation liquid-phase material flow, and the hydrofining high-pressure separation liquid-phase material flow enters a hydrofining low-pressure separator 82 for low-pressure separation to obtain a hydrofining gas and a hydrofining liquid-phase material flow; and the hydrofining liquid phase material flow is fractionated in a hydrofining fractionating tower 9 to obtain hydrofining naphtha and hydrofining diesel oil.

The hydrotreating gas obtained in the step (2) and the hydrofining gas obtained in the step (3) can be used as products independently or can be mixed to be a mixed gas product. The hydrotreated naphtha obtained in the step (2) and the hydrotreated naphtha obtained in the step (3) may be used alone as a product, or may be mixed to a mixed naphtha product. The hydrotreated diesel oil obtained in the step (2) and the hydrofined diesel oil obtained in the step (3) can be used as products independently or can be mixed into a mixed diesel oil product. The hydrotreated heavy fraction obtained in the step (2) can be used as raw oil of a catalytic cracking unit.

The hydrogen-rich gas obtained by the hydrotreatment and the hydrofining is recycled and supplemented with hydrogen to provide the hydrogen-containing gas required by the system.

The scheme and effect of the invention are further illustrated by the following examples.

In the following examples, the hydrogenation protecting agents are the hydrogenation protecting agents FZC-100, FZC-105 and FZC106 developed and produced by the smooth petrochemical research institute of China petrochemical company Limited;

the first hydrotreating catalyst and the second hydrotreating catalyst are FF-24 developed and produced by the smooth petrochemical research institute of China petrochemical company Limited;

the hydrofining catalyst is FHUDS-5 developed and produced by the smoothing petrochemical research institute of China petrochemical company Limited.

The main properties of the waxy oil feedstock and the catalytically cracked light cycle oil used are listed in table 1.

TABLE 1

Examples 1 to 3

(1) According to the system shown in fig. 1, wax oil raw oil and hydrogen-containing gas enter a hydrotreating reactor, a first hydrotreating unit 1 (a first hydrotreating catalyst bed layer) and a second hydrotreating unit 3 (a second hydrotreating catalyst bed layer) are arranged in the hydrotreating reactor, and a gas-liquid separator 2 is arranged between the first hydrotreating unit 1 and the second hydrotreating unit. A part of the first hydrotreated stream (first hydrotreated stream a) passing through the first hydrotreating catalyst bed is subjected to gas-liquid separation in the gas-liquid separator 2 to obtain a first hydrotreated gas-phase stream and a first hydrotreated liquid-phase stream, and the first hydrotreating conditions are shown in table 2;

(2) sending the rest part of the first hydrotreating material flow (the first hydrotreating material flow b), the first hydrotreating liquid-phase material flow and the hydrogen-containing gas into a second hydrotreating catalyst bed layer to obtain a hydrotreating generated material flow, sending the hydrotreating generated material flow into a hydrotreating high-pressure separator 61 for high-pressure separation to obtain a hydrotreating hydrogen-rich gas and a hydrotreating high-pressure separated liquid-phase material flow, and sending the hydrotreating high-pressure separated liquid-phase material flow into a hydrotreating low-pressure separator 62 for low-pressure separation to obtain a hydrotreating gas and a hydrotreating liquid-phase material flow; fractionating the hydrotreating liquid phase material flow in a hydrotreating fractionating tower 7 to obtain hydrotreating naphtha (distillation range is 38-150 ℃), hydrotreating diesel (distillation range is 150-365 ℃) and hydrotreating heavy fraction (distillation range is more than 365 ℃), wherein the second hydrotreating conditions are shown in Table 2;

(3) and (2) feeding the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit 4 and the first hydrotreating gas phase material flow obtained in the step (1) into a hydrofining unit 5, wherein a hydrofining catalyst bed is arranged in the hydrofining unit 5, and a hydrofining product material flow is obtained through the hydrofining catalyst bed. The hydrofining generated material flow enters a hydrofining high-pressure separator 81 for high-pressure separation to obtain a hydrofining hydrogen-rich gas and a hydrofining high-pressure separation liquid-phase material flow, and the hydrofining high-pressure separation liquid-phase material flow enters a hydrofining low-pressure separator 82 for low-pressure separation to obtain a hydrofining gas and a hydrofining liquid-phase material flow; the hydrorefining liquid phase material flow is fractionated in a hydrorefining fractionating tower 9 to obtain hydrorefined naphtha (the distillation range is 38-150 ℃) and hydrorefined diesel oil (the distillation range is more than 150 ℃), and the hydrorefining conditions are listed in Table 2.

Wherein the hydrogen-rich gas obtained by the hydrotreatment and the hydrofining is recycled and supplemented with hydrogen to provide the hydrogen-containing gas required by the system (the volume content of the hydrogen is about 88-92%).

In Table 2, the FZC series refers to a combination of 10% by volume of FZC-100, 30% by volume of FZC-105 and 60% by volume of FZC-106.

TABLE 2

The properties of the products obtained in examples 1 to 3 are shown in Table 3 below.

Comparative example 1

The wax oil raw oil (wax oil raw oil 1) and the hydrogen-containing gas enter a hydrotreating reactor, a hydrotreating catalyst bed is arranged in the hydrotreating reactor, and a hydrotreating reaction is carried out through the hydrotreating catalyst bed (the reaction conditions are the same as the first hydrotreating reaction conditions in example 1), so that a hydrotreated material flow is obtained. The hydrotreated stream is separated in a hot high pressure separator to obtain a high temperature gas phase and a liquid phase.

The high-temperature gas phase separated by the thermal high-pressure separator was mixed with the catalytic cracking light cycle oil feedstock (same as in example 1, the weight ratio of the catalytic cracking light cycle oil to the wax oil feedstock was 0.3: 1), and then a hydrofining reaction was carried out in a hydrofining reactor (same conditions as in example 1) to obtain a hydrofined product stream. The hydrorefining resultant stream was subjected to high-pressure separation and low-pressure separation in accordance with step (3) of example 1 to obtain a hydrorefining hydrogen-rich gas, a hydrorefining gas and a hydrorefining high-pressure separation liquid phase stream. The hydrorefined high-pressure separated liquid phase stream was fractionated in accordance with step (3) of example 1 to obtain hydrorefined naphtha and hydrorefined diesel.

The liquid phase separated by the hot high-pressure separator is sent to a hydrotreating fractionating tower and fractionated according to the step (2) in the example 1, and hydrotreating naphtha, hydrotreating diesel oil and hydrotreating heavy fraction are obtained.

The properties of the product obtained are listed in table 3 below.

TABLE 3

Example 4

The process of example 2 was followed except that the hydrotreating product stream and the hydrofinishing product stream were combined and then separated and fractionated together. Specifically, the method comprises the following steps:

(1) the procedure of example 2, step (1), was followed;

(2) a hydrotreating resultant stream is obtained according to step (2) of example 2;

(3) a hydrofining resultant stream is obtained according to the step (3) of the example 2;

(4) according to the system shown in fig. 2, mixing the hydrotreating generated material flow obtained in the step (2) with the hydrofining generated material flow obtained in the step (3) to obtain a mixed material flow, feeding the mixed material flow into a mixed high-pressure separator 101 for high-pressure separation to obtain a mixed hydrogen-rich gas and a mixed high-pressure separated liquid-phase material flow, and feeding the mixed high-pressure separated liquid-phase material flow into a mixed low-pressure separator 102 for low-pressure separation to obtain a mixed gas and a mixed liquid-phase material flow; the mixed liquid phase material flow is fractionated in a mixed fractionating tower 11 to obtain mixed naphtha (the distillation range is 38-150 ℃), mixed diesel oil (the distillation range is 150-365 ℃) and mixed heavy fraction (the distillation range is more than 365 ℃).

Wherein the mixed hydrogen-rich gas is recycled and supplemented with hydrogen to provide the hydrogen-containing gas required by the system (the volume content of the hydrogen is about 88-92%).

The properties of the product obtained are listed in table 4 below.

TABLE 4

Examples 5 to 7

(1) According to the system shown in FIG. 3, the first hydrotreatment and gas-liquid separation were carried out according to examples 1 to 3, and the first hydrotreatment conditions are shown in Table 5.

(2) The procedure of examples 1-3 was followed, and the second hydrotreatment conditions are set forth in Table 5;

(3) the catalytically cracked light cycle oil supplied from the catalytically cracked light cycle oil supply unit 4 was cut into light and heavy fractions by the catalytically cracked light cycle oil fractionator 12, the cutting temperatures are listed in table 5, the heavy fraction and the first hydrotreating gas-phase material flow obtained in the step (1) enter a hydrofining unit 5, a first hydrofining unit 51 (a first hydrofining catalyst bed layer) and a second hydrofining unit 52 (a second hydrofining catalyst bed layer) are arranged in the hydrofining unit 5, the heavy fraction and the first hydrotreating gas-phase material flow obtained in the step (1) pass through the first hydrofining catalyst bed layer to obtain a first hydrofining material flow, the first hydrofining material flow and the light fraction pass through the second hydrofining catalyst bed layer to obtain a hydrofining product flow, and the first hydrofining conditions and the second hydrofining conditions are listed in table 5. Separation and fractionation of the hydrofinishing product stream was carried out as in examples 1-3.

In Table 5, the FZC series refers to a combination of 10% by volume of FZC-100, 30% by volume of FZC-105 and 60% by volume of FZC-106.

TABLE 5

TABLE 5 continuation

The properties of the products obtained in examples 5 to 7 are shown in Table 6 below.

TABLE 6

The results of the embodiment of the invention show that the wax oil hydrogenation method and the system provided by the invention can be used for producing target products with different specifications according to requirements; in addition, the sulfur content in the hydrotreated naphtha, the hydrotreated diesel oil and the hydrotreated heavy distillate oil can be effectively reduced, the monocyclic aromatic hydrocarbon content in the hydrotreated diesel oil is improved, the monocyclic aromatic hydrocarbon content can be used as a high-quality catalytic cracking raw material, and the aromatic hydrocarbon content in the catalytic cracking gasoline can be improved when the high-quality catalytic cracking raw material enters a catalytic cracking device. From the comparison of examples 1-3 and examples 5-7, it can be seen that the sulfur content of the product is more advantageously reduced and the monocyclic aromatic content of the hydrorefined diesel is further increased by using the preferred embodiment of the present invention.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A wax oil hydrogenation method comprises the following steps:

2. The method as claimed in claim 1, wherein the initial boiling point of the wax oil raw oil is 100-400 ℃ and the final boiling point is 405-650 ℃.

3. The method of claim 2, wherein the wax oil feedstock is selected from at least one of virgin wax oil, coker wax oil, deasphalted oil, coal tar, coal direct liquefaction oil, coal indirect liquefaction oil, synthetic oil, and shale oil.

4. The method as claimed in claim 1, wherein the light cycle oil has an initial boiling point of 100-200 ℃ and an end boiling point of 320-400 ℃.

5. The method according to claim 1, wherein the weight ratio of the catalytic cracking light cycle oil to the wax oil raw oil is 0.1-3: 1.

6. the process of claim 1, wherein the first and second hydroprocessing catalysts each independently comprise a support and an active component selected from at least one of group VIB and/or group VIII metal elements, and the support is alumina and/or silica-containing alumina.

7. The process of claim 6, wherein the group VIB metal element is present in an amount of 10 to 35 wt.% and the group VIII metal element is present in an amount of 3 to 15 wt.% calculated as oxides, based on the total amount of the first hydrotreating catalyst; the specific surface area of the first hydrotreating catalyst is 100-650m²The pore volume is 0.15-0.6 mL/g;

based on the total amount of the second hydrotreating catalyst and calculated by oxides, the content of VIB group metal elements is 10-35 wt%, and the content of VIII group metal elements is 3-15 wt%; the specific surface area of the second hydrotreating catalyst is 100-650m²The pore volume is 0.15-0.6 mL/g.

8. The method of claim 1, wherein the first and second hydrotreating conditions each independently comprise: the reaction pressure is 3-19MPa, the reaction temperature is 300-450 ℃, and the liquid hourly space velocity is 0.2-6h^-1The volume ratio of hydrogen to oil is 100-: 1.

9. the method of claim 8, wherein the first and second hydrotreating conditions each independently comprise: the reaction pressure is 4-17MPa, the reaction temperature is 320-420 ℃, and the liquid hourly space velocity is 0.4-4h^-1The volume ratio of hydrogen to oil is 400-: 1.

10. the process of any one of claims 1-9, wherein the first hydrotreated gas phase stream comprises from 5 to 95 vol% of the hydrogen-containing gas in step (1).

11. The process of claim 10, wherein the first hydrotreated gas phase stream comprises from 10 to 80 vol% of the hydrogen-containing gas in step (1).

12. The process according to any one of claims 1 to 9, characterized in that the percentage of the first hydrotreated stream a to the total of the first hydrotreated stream a and the first hydrotreated stream b is from 5 to 95 wt%.

13. The process of claim 12, wherein the percentage of the first hydrotreated stream a to the total of the first hydrotreated stream a and the first hydrotreated stream b is in the range of 10 to 80 wt%.

14. The process of any one of claims 1 to 9, wherein the hydrofinishing catalyst comprises a carrier and an active component, wherein the active component is at least one element selected from group VIB and/or group VIII metals, and the carrier is alumina and/or silica-containing alumina.

15. The process of claim 14, wherein the group VIB metal element is present in an amount of 10 to 35 wt.% and the group VIII metal element is present in an amount of 3 to 15 wt.% on an oxide basis, based on the total amount of hydrofinishing catalyst; the specific surface area of the hydrofining catalyst is 100-650m²The pore volume is 0.15-0.6 mL/g.

16. The process of any one of claims 1-9, wherein the hydrofinishing conditions comprise: the reaction pressure is 3-19MPa, the reaction temperature is 260-450 ℃, and the liquid hourly space velocity is 0.2-6h^-1The volume ratio of hydrogen to oil is 100-: 1.

17. the method as claimed in any one of claims 1 to 9, further comprising cutting the catalytically cracked light cycle oil to obtain a light fraction and a heavy fraction, wherein the cutting temperature is 245-300 ℃; the step (3) comprises the following steps: under a first hydrofining condition, contacting a first hydrotreating gas phase material flow, a heavy fraction, hydrogen-containing gas and a first hydrofining catalyst to perform a first hydrofining reaction to obtain a first hydrofining material flow; and under second hydrofining conditions, contacting the first hydrofining material flow, the light fraction, the hydrogen-containing gas and a second hydrofining catalyst to perform a second hydrofining reaction.

18. The process of claim 17, wherein the temperature of the second hydrofinishing reaction is lower than the temperature of the first hydrofinishing reaction.

19. The process of claim 18, wherein the temperature of the second hydrofinishing reaction is 5-20 ℃ lower than the temperature of the first hydrofinishing reaction.

20. The method of any one of claims 1-9, wherein step (2) further comprises: separating and fractionating the hydrotreating generated material flow to obtain a hydrotreating hydrogen-rich gas, a hydrotreating gas, hydrotreating naphtha, hydrotreating diesel and hydrotreating heavy fraction; the step (3) further comprises the following steps: and separating and fractionating the hydrofining resultant to obtain hydrofining hydrogen-rich gas, hydrofining naphtha and hydrofining diesel.

21. The method of claim 20, wherein said separating of step (2) comprises high pressure separation and low pressure separation, said hydrotreating produced stream is subjected to high pressure separation to obtain a hydrotreating hydrogen-rich gas and a hydrotreating high pressure separated liquid phase stream, said hydrotreating high pressure separated liquid phase stream is subjected to low pressure separation to obtain a hydrotreating gas and a hydrotreating liquid phase stream, and said hydrotreating liquid phase stream is fractionated to obtain hydrotreating naphtha, hydrotreating diesel and hydrotreating heavy fraction;

and (3) separating the hydrorefining product stream by high-pressure separation to obtain hydrorefining hydrogen-rich gas and hydrorefining high-pressure separation liquid phase stream, separating the hydrorefining high-pressure separation liquid phase stream by low-pressure separation to obtain hydrorefining gas and hydrorefining liquid phase stream, and fractionating the hydrorefining liquid phase stream to obtain hydrorefining naphtha and hydrorefining diesel.

22. The method of claim 20, further comprising: recycling the hydrogen-rich gas from the hydrogenation treatment and the hydrogen-rich gas from the hydrogenation refining to provide the required hydrogen-containing gas.

23. The method according to any one of claims 1-9, further comprising: and mixing the hydrotreating generated material flow and the hydrofining generated material flow to obtain a mixed material flow, and then separating and fractionating the mixed material flow.

24. The method of claim 23, wherein the mixture stream is subjected to high pressure separation to obtain a mixed hydrogen-rich gas and a mixed high pressure separated liquid phase stream, the mixed high pressure separated liquid phase stream is subjected to low pressure separation to obtain a mixed gas and a mixed liquid phase stream, and the mixed liquid phase stream is fractionated to obtain a mixed naphtha, a mixed diesel and a mixed heavy fraction.

25. The method of claim 24, further comprising: recycling the mixed hydrogen-rich gas to provide the required hydrogen-containing gas.

26. A wax oil hydrogenation system, the system comprising:

a first hydroprocessing unit (1);

a gas-liquid separator (2), wherein the gas-liquid separator (2) is used for performing gas-liquid separation on a part of the first hydrotreating material flow obtained by the first hydrotreating unit (1) to obtain a first hydrotreating gas-phase material flow and a first hydrotreating liquid-phase material flow;

the second hydrotreating unit (3), the rest part of the first hydrotreating material flow and the first hydrotreating liquid phase material flow are subjected to second hydrotreating in the second hydrotreating unit (3) to obtain a hydrotreating generated material flow;

a catalytically cracked light cycle oil supply unit (4), the catalytically cracked light cycle oil supply unit (4) being for providing catalytically cracked light cycle oil;

and the catalytic cracking light cycle oil and the first hydrotreating gas phase material flow provided by the catalytic cracking light cycle oil supply unit (4) are subjected to hydrofining in the hydrofining unit (5) to obtain a hydrofining product flow.

27. The system of claim 26, wherein the gas-liquid separator (2) comprises a reactant stream inlet, a liquid phase conduit, and a gas phase conduit; the reactant stream inlet of the gas-liquid separator (2) is communicated with the outlet of the first hydrotreating unit (1), the first hydrotreating liquid-phase stream is introduced into the second hydrotreating unit (3) through a liquid-phase conduit, and the first hydrotreating gas-phase stream is introduced into the hydrofining unit (5) through a gas-phase conduit.

28. The system of claim 26 or 27, further comprising:

the hydrotreating separation unit comprises a hydrotreating high-pressure separator (61) and a hydrotreating low-pressure separator (62) which are connected in series, and an outlet of the second hydrotreating unit (3) is communicated with an inlet of the hydrotreating high-pressure separator (61) through a pipeline; the hydrotreating generated material flow is subjected to high-pressure separation in a hydrotreating high-pressure separator (61) to obtain a hydrotreating hydrogen-rich gas and a hydrotreating high-pressure separation liquid-phase material flow, and the hydrotreating high-pressure separation liquid-phase material flow is subjected to low-pressure separation in a hydrotreating low-pressure separator (62) to obtain a hydrotreating gas and a hydrotreating liquid-phase material flow;

the inlet of the hydrotreating fractionating tower (7) is communicated with the outlet of the hydrotreating low-pressure separator (62) through a pipeline, and the hydrotreating liquid-phase material flow is fractionated in the hydrotreating fractionating tower (7) to obtain hydrotreating naphtha, hydrotreating diesel oil and hydrotreating heavy fraction;

the hydrofining separation unit comprises a hydrofining high-pressure separator (81) and a hydrofining low-pressure separator (82) which are connected in series, and an outlet of the hydrofining unit (5) is communicated with an inlet of the hydrofining high-pressure separator (81) through a pipeline; the hydrofining generated material flow is subjected to high-pressure separation in a hydrofining high-pressure separator (81) to obtain hydrofining hydrogen-rich gas and hydrofining high-pressure separated liquid-phase material flow, and the hydrofining high-pressure separated liquid-phase material flow is subjected to low-pressure separation in a hydrofining low-pressure separator (82) to obtain hydrofining gas and hydrofining liquid-phase material flow;

and an inlet of the hydrofining fractionating tower (9) is communicated with an outlet of the hydrofining low-pressure separator (82) through a pipeline, and the hydrofining liquid phase material flow is fractionated in the hydrofining fractionating tower (9) to obtain hydrofining naphtha and hydrofining diesel oil.

29. The system of claim 28, wherein the gas phase outlets of the hydrotreating high-pressure separator (61) and the hydrofining high-pressure separator (81) are each independently in communication with the inlet of the first hydrotreating unit (1) and/or the inlet of the second hydrotreating unit (3) to recycle the hydrotreating hydrogen-rich gas and the hydrofining hydrogen-rich gas to provide hydrogen required by the system.

30. The system of claim 26 or 27, further comprising:

the mixed fractionation tower comprises a mixed separation unit and a mixed fractionation tower (11), wherein the mixed separation unit comprises a mixed high-pressure separator (101) and a mixed low-pressure separator (102) which are connected in series, and an outlet of the mixed low-pressure separator (102) is communicated with an inlet of the mixed fractionation tower (11);

the outlet of the second hydrotreating unit (3) and the outlet of the hydrofining unit (5) are communicated with the inlet of the mixing high-pressure separator (101); mixing the hydrotreating generated material flow and the hydrofining generated material flow, and then carrying out high-pressure separation in a mixing high-pressure separator (101) to obtain a mixed hydrogen-rich gas and a mixed high-pressure separation liquid phase material flow;

the mixed high-pressure separation liquid phase material flow is subjected to low-pressure separation in a mixed low-pressure separator (102) to obtain mixed gas and a mixed liquid phase material flow;

and fractionating the mixed liquid phase material flow in a mixed fractionating tower (11) to obtain mixed naphtha, mixed diesel oil and mixed heavy fraction.

31. The system according to claim 30, wherein the gas phase outlet of the hybrid high-pressure separator (101) is in communication with the inlet of the first hydroprocessing unit (1) and/or the inlet of the second hydroprocessing unit (3) for recycling the hybrid hydrogen-rich gas to provide the hydrogen required by the system.

32. The system according to claim 26, wherein the hydrofinishing unit (5) comprises a first hydrofinishing unit (51) and a second hydrofinishing unit (52) arranged in series;

the system further comprises: a catalytic cracking light cycle oil fractionating tower (12) arranged between the first hydrofining unit (51) and the catalytic cracking light cycle oil supply unit (4), wherein the catalytic cracking light cycle oil fractionating tower (12) is used for cutting the catalytic cracking light cycle oil provided by the catalytic cracking light cycle oil supply unit (4) into light fractions and heavy fractions;

said heavy fraction and said first hydrotreated gas-phase stream are hydrofinished in a first hydrofinishing unit (51) to obtain a first hydrofinished stream; the first hydrofinished stream and the light fraction are hydrofinished in a second hydrofinishing unit (52) to obtain the hydrofinished product stream.