CN110093186B

CN110093186B - Method for combined processing of catalytic cracking slurry oil

Info

Publication number: CN110093186B
Application number: CN201810083165.8A
Authority: CN
Inventors: 李华; 蒋文军; 佘喜春; 贺晓军; 陈庆岭; 曾志煜; 曾文广; 谢清峰; 罗雄威; 谢琼玉
Original assignee: Changling Branch China Petroleum Chemical Corp; China Petroleum and Chemical Corp; Hunan Changling Petrochemical Technology Development Co Ltd
Current assignee: Changling Branch China Petroleum Chemical Corp; Hunan Changlian New Material Technology Co ltd; China Petroleum and Chemical Corp
Priority date: 2018-01-29
Filing date: 2018-01-29
Publication date: 2021-04-09
Anticipated expiration: 2038-01-29
Also published as: CN110093186A

Abstract

The invention relates to the field of catalytic cracking slurry oil treatment, and discloses a combined processing method of catalytic cracking slurry oil, which comprises the following steps: (1) mixing catalytic cracking slurry oil, an amphoteric surfactant and a diluent, and contacting the obtained diluted slurry oil with water in a fiber liquid membrane contactor, wherein the fiber liquid membrane contactor comprises a mass transfer space filled with fiber filaments; (2) carrying out oil, water and solid three-phase separation on the material obtained in the step (1); (3) contacting the oil phase obtained in the step (2) with hydrogen to carry out hydrotreating; (4) and (4) extracting and distilling the hydrogenation product obtained in the step (3). The method can continuously and efficiently remove solid powder in the catalytic cracking slurry oil and improve the resource utilization rate of the catalytic cracking slurry oil.

Description

Method for combined processing of catalytic cracking slurry oil

Technical Field

The invention relates to the field of catalytic cracking slurry oil treatment, in particular to a combined processing method of catalytic cracking slurry oil.

Background

According to statistics, the primary processing amount of crude oil in 2016 year is about 5.3 hundred million t/a, wherein the total processing amount of a catalytic cracking unit is about 1.5 hundred million t/a, the amount of catalytic cracking external throwing oil slurry in China accounts for about 5% -10% of the processing amount of an FCC unit, and the yield of the catalytic cracking oil slurry reaches more than 7.5 Mt/a. With the large background of increasing heaviness and deterioration of the catalytic feedstock, the production of oil slurries must increase. In order to improve the yield of light oil, the catalytic cracking unit in China mostly adopts oil slurry recycling operation. The heavy feedstock has many adverse effects on catalytic cracking, especially coking and fouling that can prevent the unit from operating properly. Therefore, in order to optimize production operation, most domestic refineries adopt measures of reducing the oil slurry recycling ratio and throwing partial oil slurry outside. The thrown oil slurry is generally used as a fuel oil blending component, and the economic benefit is poor. And because the slurry oil contains catalyst solid powder, the nozzle of the heating furnace is easy to wear, and dust is deposited on the surface of the heating furnace tube, so that the energy consumption is reduced and the environment is polluted. Therefore, the reasonable utilization of oil slurry resources to produce high value-added products and the improvement of refinery benefits are problems to be solved urgently by most oil refining enterprises at present.

The catalytic cracking oil slurry is mainly composed of polycyclic aromatic hydrocarbons, comprises a mixture of aromatic hydrocarbons, alkanes, asphaltenes, colloids, catalyst powder and the like, contains a large number of polycyclic (3-5) aromatic hydrocarbons with short side chains, and is a high-quality raw material for producing high-value-added products such as needle coke, carbon fibers, carbon black, rubber filling oil, heat conduction oil, road asphalt and the like. In addition, if the catalytic cracking slurry oil can be subjected to hydro-upgrading and then is subjected to other subsequent lightening processes to produce gasoline and diesel oil components with vigorous market demands, the method also has good economic benefits. However, the higher catalyst solid powder content in the catalytic slurry oil affects the subsequent process treatment and the quality of the deep-processed product. For example, carbon black or rubber extender oil production requires a solids content of no more than 500ppm, needle coke production requires a solids content of no more than 100ppm, and carbon fiber production or hydroprocessing requires a solids content of no more than 20 ppm. Therefore, the removal of solid powder catalyst in oil slurry is an essential prerequisite for high value-added comprehensive utilization.

At present, the purification technology of catalytic slurry oil at home and abroad mainly comprises flocculation sedimentation, centrifugation, hydrocyclone, filtration, electrostatic separation and other technologies. Among them, the filtration, electrostatic separation and hydrocyclone separation techniques have good separation effects and are easy to industrialize, but all have the problems of difficulty in realizing long-period stable operation, high solid content (not less than 100ppm) in the purified oil slurry and the like. In order to solve the problems, domestic researchers develop combined technical research of catalytic slurry oil purification and deep processing utilization so as to realize high-added-value comprehensive utilization of slurry oil.

CN104312620B discloses a combined method for removing catalyst powder from oil slurry and extracting oil slurry solvent. The method comprises the following steps: mixing the catalytic slurry oil and a solvent, stirring for 20-40 minutes, heating to 200 ℃, carrying out suction filtration or centrifugal separation to obtain solid catalyst powder, adding the solvent into the obtained mixed solution, standing and extracting at the temperature of 60-120 ℃ to obtain extract liquid and raffinate, distilling the solvent respectively to obtain extract oil and raffinate oil, returning the raffinate oil to a catalytic device, and selling the raffinate oil as fuel oil. The method has the defects of large using amount of the extraction solvent, large loss, unclean removal of the catalyst solid powder in the oil slurry and difficult realization of industrial continuous production.

CN104327879B discloses a combined process for producing fuel oil, aromatic oil and asphalt. The catalytic oil slurry or the mixed raw material is sent to a heating furnace for heating, and then enters a visbreaking reactor for thermal cracking, and the reaction product enters a vacuum tower for separation to obtain gas, solvent oil, fuel oil, aromatic oil and asphalt. Although the method does not need to separate solid particles in the oil slurry, the oil slurry mainly comprises polycyclic aromatic hydrocarbon, the visbreaking thermal cracking product mainly comprises heavy oil, the additional value is not high, and coke is easily generated in the thermal cracking process.

CN103361112B discloses a device and a method for blending catalytic cracking slurry oil in a delayed coking process. The method comprises the following steps: directly conveying the high-temperature slurry oil to a slurry oil tank from a catalytic cracking device, and conveying the slurry oil to a heating furnace by a slurry oil pump to be heated to 505 ℃ and 550 ℃; the high-temperature coking oil heated by the slurry oil heating furnace is mixed with the high-temperature coking oil at the outlet of the mixed oil heating furnace of the delayed coking device, and then enters a coke tower through a four-way valve for subsequent reaction. The method has the disadvantages that solid particles and alkaline nitrogen in the slurry oil are not removed, the proportion of blending delay coking is limited, coking products mainly comprise coking gas and heavy wax oil, and the overall economic benefit of the device is poor.

CN106479563A discloses a distillation and thermal cracking combined process for catalytic cracking slurry oil. The method comprises the following steps: and carrying out reduced pressure distillation on the catalytic cracking slurry oil to obtain a light oil fraction and topped mixed oil, carrying out thermal cracking on the mixed oil to obtain the light oil fraction and the mixed oil, wherein the light oil fraction is used as a fuel oil blending component, and the mixed oil is used as a road asphalt blending component. The method has the defects that the oil slurry mainly comprises polycyclic aromatic hydrocarbon, the thermal cracking product mainly comprises heavy oil and coke, and the additional value is not high.

CN106147835A discloses a combined method for separating catalytic cracking slurry oil and preparing oil-based needle coke. The method comprises the steps of performing subcritical or supercritical extraction on catalytic oil slurry by using C3-C5 light hydrocarbon fractions as an extracting agent, preparing an extraction component from an obtained extraction oil phase through a supercritical recovered solvent, preparing intermediate phase asphalt from the extraction component through thermal polycondensation, and performing delayed coking on the intermediate phase asphalt to prepare high-quality needle coke. When the sulfur content of the catalytic cracking slurry oil is high, the extracted components can be subjected to hydrodesulfurization treatment, hydrogenated oil is subjected to fractionation, and hydrogenated tail oil is taken as a mesophase pitch raw material. The method has the disadvantages that light hydrocarbon fractions are used as an extracting agent, the loss is large, and the total resource utilization rate of the oil slurry is low because a certain fraction section of the oil slurry is taken as a raw material of the needle coke.

CN102443438A discloses a hydrocarbon oil pretreatment and catalytic cracking combined process. The method comprises the following steps: carrying out deasphalting treatment on the mixed oil raw material and the catalytic cracking slurry oil; mixing the deasphalted oil and the reduced-pressure deep-drawing wax oil for hydrogenation demetalization; the hydrogenation product is mixed with one or two of light wax oil or coking wax oil for hydrogenation treatment, and the liquid phase separated from the hydrogenation effluent is a catalytic cracking raw material; the catalytic cracking slurry oil is circulated back to the solvent deasphalting device for processing. The method has the disadvantages that the deoiled asphalt is not well utilized, and the utilization rate of oil slurry resources is not high.

In summary, the existing catalytic cracking slurry oil processing and utilizing technology has the defects that the removal of solid powder catalyst in slurry oil is not clean, and the high value-added comprehensive utilization rate of slurry oil resources is not high.

Disclosure of Invention

The invention aims to overcome the defects of unclean removal of solid powder catalyst in oil slurry and low comprehensive utilization rate of high added value of oil slurry resources in the catalytic cracking oil slurry processing and utilizing technology in the prior art, and provides a method for combined processing of catalytic cracking oil slurry. The method can continuously and efficiently remove solid powder in the catalytic cracking slurry oil and improve the resource utilization rate of the catalytic cracking slurry oil.

In order to achieve the above object, the present invention provides a method for combined processing of catalytic cracking slurry oil, wherein the method comprises:

(1) mixing catalytic cracking slurry oil, an amphoteric surfactant and a diluent, and contacting the obtained diluted slurry oil with water in a fiber liquid membrane contactor, wherein the fiber liquid membrane contactor comprises a mass transfer space filled with fiber filaments;

(2) carrying out oil, water and solid three-phase separation on the material obtained in the step (1);

(3) contacting the oil phase obtained in the step (2) with hydrogen to carry out hydrotreating;

(4) and (4) extracting and distilling the hydrogenation product obtained in the step (3).

The method of the invention can maximize the high value-added utilization of the catalytic slurry oil resource; the fiber liquid membrane is adopted for purification and solid removal treatment, and as the oil-water two phases are subjected to contact elution on the planar membrane, the method has the advantages of large reaction area, high mass transfer efficiency, difficult oil-water emulsification formation, good effect of removing solid powder in oil and continuous large-scale operation; meanwhile, the balance of the original oil slurry on the action of coating an oil film on the catalyst powder is broken through the electrostatic attraction effect of the charged groups of the amphoteric surfactant and the catalyst powder, and a hydrophilic solid impurity coating layer is finally formed; and the running period of the mixed oil hydrogenation device is prolonged, so that the catalytic cracking slurry oil resource is fully utilized with high added value.

Drawings

FIG. 1 is a flow chart of the catalytic cracking slurry oil combined processing technology of the invention.

Description of the reference numerals

1, catalytically cracking oil slurry; 2 a diluent;

3, mixing the materials in a tank; 4, water;

5a fiber liquid membrane contactor; 6, a settling tank;

7 solid phase; 8, an aqueous phase;

9 oil phase; 10 a membrane mixer;

11 hydrogen gas; a 12-tube reactor;

13 reaction effluent; 14 stripping column;

15 a hydrogen sulfide-containing gas; 16 a fractionation column;

17 a gaseous hydrocarbon product; 18 gasoline fraction;

19 a diesel fraction; 20 a heavy oil fraction;

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 invention provides a method for combined processing of catalytic cracking slurry oil, wherein the method comprises the following steps:

In the present invention, preferably, the amphoteric surfactant is at least one of an amino acid type amphoteric surfactant, a betaine type amphoteric surfactant, and an imidazoline type amphoteric surfactant; further preferably, the amphoteric surfactant is at least one of sodium lauriminodipropionate, lauryl betaine and imidazoline laurate quaternary ammonium salt.

In the invention, the catalytic cracking slurry oil is diluted by adding the diluent, so that the density of the catalytic cracking slurry oil is less than that of water, thereby being beneficial to the subsequent oil-water separation, and the diluent can effectively dissolve a large amount of colloid and asphaltene in the catalytic slurry oil to a great extent, destroy the coating layer and the interaction force of the slurry oil on the catalyst powder, and simultaneously reduce the viscosity of the slurry oil. Preferably, the diluent is a mixed solution of a hydrocarbon solvent and an ester solvent;

in the present invention, in order to further enhance the above effect of the diluent, it is preferable that the volume ratio of the hydrocarbon solvent to the ester solvent is from 2 to 20: 1, more preferably 5 to 10: 1.

the method can process catalytic cracking slurry oil from various sources, and the catalytic cracking slurry oil raw material is mixed with the diluent before the reaction, so that the viscosity and the density of the catalytic cracking slurry oil raw material can be reduced, and the mass transfer effect can be better realized when the solid-containing slurry oil is treated in the fiber liquid membrane contactor. Preferably, the diluent has a density of 0.8 to 0.95g/cm³. The density is 20 deg.C, and the viscosity of the diluent is not higher than 3.5mm at 100 deg.C²S, of the diluted slurryDensity not higher than 1.0g/cm³Thus, better solid removal and purification effects can be obtained.

In the invention, the hydrocarbon solvent can be a hydrocarbon compound which can be used for diluting oil slurry in the field, preferably, the hydrocarbon solvent is at least one of atmospheric diesel oil, atmospheric hydrogenated diesel oil, coked diesel oil, catalytic diesel oil, hydrogenated coked diesel oil, hydrogenated catalytic diesel oil and diesel fraction obtained by fractionating coked heavy wax oil, catalytic clarified oil, catalytic recycle oil and visbreaking light oil after hydrogenation, and further preferably at least one of atmospheric diesel oil, catalytic diesel oil and diesel fraction obtained by fractionating catalytic recycle oil after hydrogenation;

in the present invention, the ester solvent may be an ester compound that can be used in the art to dilute the slurry oil, and preferably, the ester solvent is at least one of esters generated by esterification reaction of a fatty acid having 2 to 12 carbon atoms and a fatty alcohol having 1 to 12 carbon atoms, and more preferably at least one of ethyl acetate, ethyl butyrate, ethyl caproate, ethyl laurate, n-butyl acetate, hexyl acetate, and lauryl acetate; more preferably at least one of ethyl acetate, ethyl laurate and n-butyl acetate.

In the present invention, the amount of the amphoteric surfactant and the diluent may be selected according to the treatment amount of the slurry oil, but in order to achieve better slurry oil de-solidification effect and subsequent re-treatment effect, preferably, in step (1), the weight ratio of the amount of the catalytic cracking slurry oil, the amount of the amphoteric surfactant and the amount of the diluent is 1: 0.00005-0.0005: 0.2 to 3, preferably 1: 0.0001-0.0003: 0.5-1.5.

In the invention, after the diluted oil slurry is contacted with the water fiber liquid membrane contactor, the solid powder in the oil slurry enters the water under the action of the amphoteric surfactant with hydrophilic property, thereby achieving the effect of oil slurry de-solidification. Preferably, in the step (1), the weight ratio of the diluted oil slurry to the water is 1: 0.05 to 0.3, preferably 1: 0.07-0.2.

In the present invention, in order to further enhance the slurry oil de-solidification effect, preferably, in step (1), the contacting conditions include: the temperature is 80-200 ℃, preferably 130-150 ℃; the pressure is 0.3-3MPa, preferably 1-1.8 MPa. The temperature is the operating temperature of the fiber liquid membrane contactor, the pressure is the working pressure of the fiber liquid membrane contactor, and the pressure is gauge pressure.

According to a preferred embodiment of the present invention, the diluted slurry oil is preheated and then mixed with water. The diluted oil slurry is preheated, so that the oil slurry is further completely dissolved in the diluent, and the contact and solid removal effect of the diluted oil slurry and water is improved. The temperature of the preheating is preferably 50 to 150 ℃, preferably 60 to 100 ℃.

According to the invention, the fiber filaments have good hydrophilicity, and can capture the amphoteric surface activity and the inclusion and water formed by the catalyst powder, so that the catalytic cracking slurry oil is fully de-solidified.

Specifically, the amphoteric surfactant has positive charges and negative charges and an isoelectric point, when the amphoteric surfactant is dispersed on the fiber yarn with water, electron-enriched colloid and asphaltene in an oil phase are not easy to gather on the fiber yarn, so that blockage is avoided, a liquid film containing catalyst powder moves along the fiber yarn, is continuously coalesced to form large liquid drops, and drops off under the action of self gravity, and finally, the oil slurry after solid removal is obtained through three-phase separation of oil, water and solid.

The fiber liquid membrane contactor in the invention is a high-efficiency mass transfer device. The fiber liquid film contactor can be a device with two open ends, the two ends are respectively a feeding end and a discharging end, the feeding end is provided with two feeding ports, and the discharging end is connected with subsequent equipment for oil-water-solid separation. The fiber liquid membrane contactor can be further provided with a fluid distributor and a mass transfer space cylinder from the feeding end to the discharging end, a fluid redistributor and fiber yarns can be sequentially arranged in the mass transfer space cylinder from the feeding end to the discharging end, the fluid distributor and the fluid redistributor can be selected from one of a perforated plate type fluid distributor, an overflow type fluid distributor and a plate type fluid distributor, and more than one set of fluid redistributors can be arranged. The fluid distributor and the fluid redistributor enable the solid-containing fluid entering the fiber liquid film contactor to be well distributed on the cross section of the fiber filaments, so that the mass transfer effect of the fluid in the fiber liquid film contactor is better. The fiber filaments are arranged in a mass transfer space cylinder of a fiber liquid membrane contactor of a fiber liquid membrane reactor, fluid which is uniformly distributed by a distributor flows through the fiber filaments, and the water phase and the oil phase which are added into the fiber liquid membrane contactor form a liquid membrane on the surface of the fiber filaments by utilizing the difference of capillary action and the surface tension of the water phase and the solid oil-containing phase on the fiber filaments, so that the contact surface area of the two phases is increased, the mass transfer efficiency is greatly improved, the improved mass transfer efficiency can promote the water phase to be more effectively contacted with catalyst powder in oil, the effect of a catalyst can be better played, and the de-solidification of an oil slurry raw material is realized.

In the present invention, the fiber liquid membrane contactor may have various shapes as long as the fiber filaments are released from the fiber liquid membrane contactor, and preferably, the fiber liquid membrane contactor is a cylindrical body. The fiber liquid membrane contactor of the cylinder can fully utilize the direction of the material flow and the self weight of the liquid drops to perform the solid removal.

In the present invention, preferably, the aspect ratio of the mass transfer space is 10 to 60: 1, the filling rate of the fiber filaments in the mass transfer space is 2-30 volume percent.

In the present invention, the fiber filament may be an existing fiber material having hydrophilicity, and the fiber filament may be a metal filament and/or a non-metal filament, and preferably, the fiber filament is at least one of a stainless steel wire, a carbon steel wire, a glass fiber filament, a polyamide fiber filament, and a polyester fiber filament; further preferably, the fiber yarn is at least one of stainless steel yarn, glass fiber yarn and polyester fiber yarn. The fiber yarn may be an industrially produced product, and for example, the fiber yarn may be a commercially available 316 series stainless steel wire, a 0.05mm glass fiber yarn and a polyester fiber yarn.

In the present invention, in order to further improve the de-solidification effect of the slurry, the diameter of the fiber filament is preferably 0.05-0.5 mm.

In the present invention, even though the feeding rate of the diluted slurry oil and water into the fiber liquid membrane contactor may be varied within a wide range, in order to improve the contact efficiency of the diluted slurry oil and waterPreferably, in the step (1), the liquid hourly space velocity of the diluted oil slurry fed is 5-60h based on the volume of the fiber filaments^-1Preferably 10-20h^-1。

In the present invention, in the step (2), the process of separating the three phases of oil, water and solid can be performed by using the conventional operation manner in the art, for example, in the step (2), the process of separating the three phases of oil, water and solid is performed by means of sedimentation and filtration. Specifically, the settling process may be standing a mixture obtained after contacting the diluted oil slurry with water in an oil-water separation tank, discharging the lower layer after standing, and precipitating and filtering to obtain a water phase and a solid phase, wherein the upper layer is an oil phase and the lower layer is water containing solid impurities. The separated water phase can be recycled. The process of settling may be carried out in a settling tank.

In the present invention, the settling time may be selected according to the effect of the separation of the oil-water layer of the actual mixed solution, and is preferably 0.5 to 3 hours, more preferably 1 to 2 hours.

In the invention, the obtained solid slag can be burnt and regenerated according to the requirements of catalytic cracking slurry oil treatment and can be used as a regenerated catalyst of a catalytic cracking device; the mixed raw material of the removed solid and water is treated by the method for solid removal treatment in the invention again, namely, secondary solid removal treatment is carried out, so that the solid content in the mixed raw oil obtained after treatment by the method in the invention can be further reduced, and the further improved effect can be obtained.

In the present invention, the hydrotreating process may include: and (3) boosting the pressure of the oil phase obtained in the step (2), exchanging heat to the temperature required by liquid phase hydrogenation reaction, mixing the oil phase with hydrogen in a membrane mixer, and contacting the oil phase system with a catalyst with catalytic hydrodesulfurization, nitrogen and aromatic saturation effects in at least two tubular fixed bed reactors connected in series under the condition of liquid phase hydrogenation treatment to perform hydrogenation modification reaction.

In the present invention, the membrane mixer includes a housing and a membrane module. The membrane mixer is characterized in that at least one membrane module is arranged in a shell, and a space exists between the outer wall of the membrane module and the inner wall of the shell. The channel on the membrane module is used as a liquid channel for containing the mixed oil raw material (the oil phase obtained in the step (2), the same below), and the space formed by the outer wall of the membrane module and the inner wall of the shell is used as the gas channel for containing hydrogen; or, the channel on the membrane module is used as the gas channel for accommodating hydrogen, and the space formed by the outer wall of the membrane module and the inner wall of the shell is used as the liquid channel for accommodating the mixed oil raw material. Preferably, the channel on the membrane module is used as the liquid channel for accommodating the mixed oil raw material, and the space formed by the outer wall of the membrane module and the inner wall of the shell is used as the gas channel for accommodating hydrogen.

The material forming the membrane module may be an inorganic material (e.g., an inorganic ceramic) or an organic material, as long as the material forming the member does not chemically interact with hydrogen gas and mixed oil. The membrane module is formed of a porous material in which pores have an average pore diameter of nanometer size. The membrane module may also include a base having a through-hole, and a porous membrane attached to the base, and the porous membrane may be located on a surface of the base reacting with the mixed oil raw material received in the liquid passage, or may be located on a surface of the base reacting with the hydrogen gas received in the gas passage. Preferably, the porous membrane is located on a surface of the substrate that reacts with the mixed oil raw material received in the liquid channel. The pores in the porous membrane are pores having an average pore diameter of nanometer size. The average pore diameter of the through-holes in the substrate is not particularly limited as long as a gas can pass through the through-holes. Preferably, the average pore size of the through-holes in the substrate is 1nm to 1000 μm (e.g., 50-200 μm). The membrane module may typically be filled in the housing at a rate of from 10 to 90%, such as from 50 to 70%. The fill factor refers to the percentage of space occupied by the membrane module to the total volume of the housing.

In the present invention, the average pore diameter of the pores of the membrane module may be generally 1nm to 1000nm, preferably 30nm to 1000nm, more preferably 30nm to 800nm, and further preferably 50nm to 500 nm. The average pore diameter is determined by a scanning electron microscope method. From the viewpoint of further improving the effect of dispersing and mixing hydrogen in the mixed oil raw material and thereby allowing hydrogen to be dispersed more quickly and uniformly in the mixed oil raw material, the proportion of the number of pores having a pore diameter in the range of 50 to 500nm to the total number of pores is 95% or more, for example, 95 to 98%.

In the invention, when the channel on the membrane module is used as a liquid channel for containing the mixed oil raw material, and the space formed by the outer wall of the membrane module and the inner wall of the shell is used as a gas channel for containing hydrogen, the hydrogen is sent into the shell through the gas inlet, the mixed oil raw material is sent into the channel of the membrane module, and the hydrogen enters the mixed oil raw material through the holes on the tube wall under the action of pressure difference, so that the hydrogen and the mixed oil raw material are mixed in a cross flow manner.

According to the present invention, hydrogen gas may be injected into the mixed stock oil that is stationary, or hydrogen gas may be injected into the mixed stock oil that is in a flowing state. Preferably, hydrogen is injected into the feedstock oil in a fluidized state, so that not only a good hydrogen dispersion and dissolution effect can be obtained, but also a high production efficiency can be obtained.

In the present invention, the amount of hydrogen gas mixed into the mixed oil feedstock may be selected according to the content of impurities in the mixed oil feedstock. In the existing heavy oil hydrogenation process, the consumption of hydrogen is large, and the volume ratio of the hydrogen to the heavy oil raw material is generally more than 700. The method of the invention feeds hydrogen into the mixed oil raw material through nanometer-sized holes with average pore diameter, so that the hydrogen can be highly dispersed and dissolved in the mixed oil raw material, thereby providing enough hydrogen source for hydrogenation reaction; in addition, in the method of the present invention, the hydrogenation reaction is carried out in a liquid phase, and the reaction heat can be taken out in time. Therefore, the method of the present invention can obtain good hydrotreating effect and reduce the tendency of coking of the catalyst even if the amount of hydrogen fed into the mixed oil feedstock is reduced. According to the method of the invention, the amount of the introduced hydrogen is 1-2 times of the consumption of the hydrogen in the catalytic slurry oil hydrogenation under the reaction conditions, namely the amount of the introduced hydrogen is 2.0-10.0 m%, preferably 3.5-7.0 m% of the catalytic slurry oil raw material.

In the present invention, it is preferable to feed hydrogen gas into the heated mixed oil raw material, which enables hydrogen gas to be better dissolved and dispersed in the mixed oil raw material. Preferably, hydrogen is fed to the mixed oil feedstock at a temperature and pressure at the hydrogenation temperature and hydrogenation pressure, which further reduces the tendency of hydrogen to escape from the hydrogen-containing mixed oil. Specifically, hydrogen can be fed into the mixed oil raw material with the temperature of 300-450 ℃ and the pressure of 4-20 MPa.

The tubular reactor refers to a reactor having a large length-diameter ratio. In particular, the tubular reactor may have a ratio of length to internal diameter of 5 to 200: 1 (e.g., 10-20: 1). The internal diameter of the tubular reactor may be conventionally selected and may for example be in the range 20 to 2000mm (e.g. 50 to 500 mm). Compare with kettle-type reactor, adopt tubular reactor can reduce the volume of reactor on the one hand, on the other hand is through the foregoing during membrane mixer, directly will the membrane mixer sets up tubular reactor's material inlet pipeline can, flexible operation and convenience.

In the present invention, the hydrogen-containing mixed oil may be fed into the tubular reactor in an upward flow manner or in a downward flow manner. Preferably, the hydrogen-containing mixed oil is fed into the tubular reactor in an upward flowing mode, so that hydrogen dissolved and dispersed in the mixed oil is basically not gathered to form large bubbles and escapes in the reaction process, the hydrogen consumed in the reaction process is supplemented in time, and a sufficient reaction hydrogen driving force is provided for hydrogenation reaction, and a better hydrogenation treatment effect is obtained; the catalyst is completely soaked in the materials, no reaction dead zone exists, and the catalyst keeps higher catalytic activity; the reaction has uniform heat release, and the specific heat capacity of the liquid is larger, so that the coke formation tendency of the catalyst can be reduced, the service life of the catalyst is prolonged, and the stable operation period of the hydrogenation device is further prolonged.

The reaction of the hydrogen-containing mixed oil and the hydrogenation catalyst can be carried out at the conventional mixed oil hydrotreating temperature and pressure. Generally, the temperature can be 300-450 deg.C and the pressure can be 4-20MPa (e.g., 10-20 MPa). The space velocity of the hydrogen-containing mixed oil can also be selected conventionally. The inventionThe method can obtain better hydrogenation effect even if the hydrogen-containing mixed oil passes through the hydrogenation catalyst at higher space velocity. Therefore, the volume space velocity of the hydrogen-containing mixed oil in the method of the invention is preferably 0.5-5h^-1(e.g. 2-4 h)^-1)。

In the present invention, the number of the tubular reactors is at least 2, and may be 2 or more. When the number of the tubular reactors is more than 2, the tubular reactors are connected in series, or can be connected and combined in parallel after being connected in series. The serial connection means that the hydrogenated material flow output by the previous tubular reactor is the feed of the next tubular reactor; the parallel connection means that there is no material exchange between the tubular reactors.

In the invention, the hydrogenation catalyst can be various catalysts with catalytic hydrodesulfurization, nitrogen and aromatic saturation functions commonly used in the field of hydrogenation of mixed oil. Generally, the hydrogenation catalyst comprises a carrier and a group VIB metal, preferably molybdenum and/or tungsten, and a group VIII metal, preferably cobalt and/or nickel, supported on the carrier. The loading amounts of the group VIB metal and the group VIII metal on the carrier may be selected according to the kind of the hydrogenation catalyst. Generally, the group VIB metal may be present in an amount of from 1 to 25 wt.% and the group VIII metal may be present in an amount of from 0.5 to 8 wt.%, based on the total amount of hydrogenation catalyst and calculated as oxides. The support may be any of a variety of refractory inorganic oxides suitable as supports for hydrogenation catalysts, such as silica and/or alumina. The carrier of the hydrogenation catalyst can also be loaded with various commonly used auxiliary agents, and the details are not described herein.

In the invention, most of S, N heteroatoms in the heavy oil fraction obtained by distillation in the step (4) are removed in the liquid phase hydrogenation process, the colloid and the asphaltene are effectively converted, the harm of alkaline nitrogen to catalytic acid centers and the formation of coke precursors can be basically eliminated, and the subsequent processing process is facilitated.

According to a preferred embodiment of the invention, the method further comprises: returning the diesel fraction obtained in the distillation process of step (4) to step (1) as at least part of the diluent. The distillation range of the diesel fraction is 170-360 ℃. The diesel fraction after the hydrogenation modification of the device is adopted to be circulated as the diluent, so that the viscosity and the density of the catalytic cracking slurry oil can be reduced, a good membrane de-solidification effect can be achieved, the loss of the added diluent can be reduced, the heat release of heavy oil products in the hydrogenation process can be reduced, the service life of the catalyst can be prolonged, and the stable operation period of the hydrogenation device can be prolonged.

The combined processing method of catalytic cracking slurry oil according to one embodiment of the invention is described below with reference to the attached drawing 1: the catalytic cracking slurry oil 1, the diluent 2 and the two-type surfactant are mixed in a mixing tank 3, the obtained diluted slurry oil is contacted with water 4 in a fiber liquid membrane contactor 5 for solid removal, a mixture discharged from the fiber liquid membrane contactor 5 is settled in a settling tank 6 for gas-liquid-solid three-phase separation to obtain a solid phase 7, a water phase 8 and an oil phase 9, the oil phase 9 is mixed with hydrogen 11 in a membrane mixer 10 and then enters a tubular reactor 12 for hydrogenation reaction, a reaction effluent 13 after two-stage hydrogenation treatment enters a stripping tower 14 for stripping, the obtained hydrogen sulfide-containing gas 15 is discharged from the top of the stripping tower 14, the obtained liquid phase component enters a fractionating tower 16 for distillation treatment, the obtained gaseous hydrocarbon product 17 and a gasoline fraction 18 are discharged from the upper part of the fractionating tower, and the obtained diesel fraction 19 is returned to the mixing tank 3.

The present invention will be described in detail below by way of examples.

In the following examples, the hydrotreating conditions were: the average pore diameter of the pores of the membrane mixer is 50nm, and the proportion of the number of pores with the pore diameter in the range of 50-55nm to the total number of pores is 98%; a channel on the membrane module pipeline is used as a liquid channel, a space formed by the outer wall of the pipeline and the inner wall of the shell is used as a gas channel, and the filling rate of the pipeline in the shell is 60%; the two tubular reactors are respectively filled with a mixed oil hydrodesulfurization, nitrogen catalyst and an aromatic hydrocarbon saturation catalyst, the brands are respectively HDD-1 and DC-301, the filling height-diameter ratio of the catalyst in the tubular reactors is 14, and the process conditions of the hydro-upgrading are as follows: the primary reaction temperature is 320 ℃, the secondary reaction temperature is 360 ℃, the pressure is 12.0MPa, and the hydrogen mixing amount of a single reactor is 1.41m percent (the volume ratio of hydrogen to oil)150:1) and the total volume space velocity of 0.5h^-1。

Example 1

(1) Mixing No. 1 catalytic cracking slurry (shown in Table 1), sodium laurimidodipropionate and diluent (atmospheric diesel oil/ethyl acetate volume ratio of 5: 1, density of 0.86 g/cm)³) According to the mass ratio of 1: 0.0001: 1.5 mixing and diluting, and preheating to 100 ℃. The fiber filaments in the mass transfer space cylinder of the fiber liquid membrane contactor are 316 series stainless steel wires (the diameter is 0.05mm), and the length-diameter ratio of the mass transfer space of the cylinder is 60: 1, the filling rate of the cylinder is 5 vol%, and the volume of the fiber liquid membrane contactor is 0.3L. The preheated diluted oil slurry is stirred for 20 hours at the hourly space velocity^-1Injecting into the fiber liquid membrane contactor while injecting 10 wt% (relative to the diluted slurry oil) into the fiber liquid membrane contactor; the contact temperature in the fiber liquid membrane contactor was 130 ℃ and the contact pressure was 1 MPa.

(2) And standing and settling the mixed phase of the diluted oil slurry and water in an oil-water separation tank for 2 hours, separating oil and water phases, precipitating and filtering the lower-layer water phase, repeatedly injecting the lower-layer water phase into a fiber liquid membrane contactor for recycling, recovering catalyst solid powder, mixing the upper-layer oil phase with hydrogen in a membrane mixer, and then introducing the mixture into a tubular reactor for hydrotreating. The apparatus was operated stably for 8000 hours.

(3) And (3) separating the hydrogenated oil in a stripping tower and a fractionating tower respectively to obtain a gasoline fraction, a diesel oil fraction and a heavy oil fraction, wherein the diesel oil fraction is returned to the step (1) to be used as a part of diluent.

In this example, the apparatus was allowed to run stably for 8000 hours, and properties of the catalytically cracked slurry, diluted slurry, de-solidified slurry and hydrogenated product oil were as shown in Table 1.

TABLE 1

As can be seen from Table 1, the combined process of the present invention for treating catalytic cracking slurry oil can also effectively remove the catalyst solid powder in the catalytic slurry oil, and reduce the viscosity, density and carbon residue.

Example 2

(1) Mixing 2# catalytic cracking slurry oil (shown in Table 2), lauryl betaine and diluent (coking diesel oil and ethyl laurate volume ratio of 10: 1, density of 0.862 g/cm)³) According to the mass ratio of 1: 0.0003: 0.5 mixing dilution, preheating to 50 ℃. The fiber filaments in the mass transfer space cylinder of the fiber liquid membrane contactor are 316 series stainless steel wires (the diameter is 0.05mm), and the length-diameter ratio of the mass transfer space of the cylinder is 10: 1, the filling rate of the cylinder is 30 volume percent, and the volume of the fiber liquid membrane contactor is 0.3L. The preheated diluted oil slurry is stirred for 10 hours according to the liquid hourly space velocity^-1Injecting into the fiber liquid membrane contactor while injecting 10 wt% (relative to the diluted slurry oil) into the fiber liquid membrane contactor; the contact temperature in the fiber liquid membrane contactor was 150 ℃ and the contact pressure was 1.8 MPa.

(2) And standing and settling the mixed phase of the diluted oil slurry and water in an oil-water separation tank for 1h, separating oil and water phases, precipitating and filtering the lower-layer water phase, repeatedly injecting the lower-layer water phase into a fiber liquid membrane contactor for recycling, recovering catalyst solid powder, mixing the upper-layer oil phase with hydrogen in a membrane mixer, and then introducing the mixture into a tubular reactor for hydrotreating. The apparatus was operated stably for 8000 hours.

(3) Separating hydrogenated oil in a stripping tower and a fractionating tower respectively to obtain gasoline fraction, diesel oil fraction and heavy oil fraction, blending part of the heavy oil fraction into a hydrocracking raw material, wherein the blending amount accounts for 20 wt% of the hydrocracking raw material, the commercial brand of the hydrocracking catalyst is RHC-5, the hydrocracking catalyst is produced by Changling division company of China petrochemical catalyst company, and the hydrocracking operation conditions are as follows: the reaction temperature is 370 ℃, the reaction pressure is 15.0MPa, and the volume space velocity is 0.8h^-1Total hydrogen-oil volume ratio 1200; part of heavy oil fraction is blended into catalytic cracking raw material, the blending amount accounts for 20 wt% of the catalytic cracking raw material, the commercial brand of the catalytic cracking agent is DFC-1, the catalytic cracking agent is produced by Changling division of China petrochemical catalyst company, and the operating conditions of the catalytic cracking are as follows: the reaction temperature is 510 ℃, the reaction pressure is 0.1MPa, and the agent-oil ratio is 6.0; blending part of heavy oil fraction into delayed coking feedstock in an amount of 20 wt% of the delayed coking feedstock, and operating the delayed coking unitThe conditions are as follows: the outlet temperature of the heating furnace is 500 ℃, the top temperature of the coke tower is 440 ℃, the water injection amount accounts for 2.0 percent of the weight of the feeding amount, the circulation ratio is 0.2, the pressure at the top of the coke tower is 0.1MPa, and the agent-oil ratio is 6.0.

In this example, the properties of the catalytically cracked slurry oil, the diluted slurry oil, the de-solidified slurry oil and the hydrogenated product oil are shown in Table 2.

TABLE 2

Comparative example 1

The combined processing of the catalytic cracking slurry oil was carried out according to the method of example 2, except that the fiber liquid membrane contactor was not used for the de-solidification, and the diluted slurry oil was directly passed through a membrane mixer for the tubular fixed bed liquid phase hydrogenation reaction. The properties of the resulting hydrogenated oil are shown in Table 3, and the test unit was operated for 120 hours with plugging.

TABLE 3

As can be seen from the comparison of the results of comparative example 1 and example 2, the slurry oil after the solid removal treatment by the method of the invention has better effect of hydrotreatment.

Comparative example 2

The combined catalytic cracking slurry processing was carried out as in example 2, except that the same weight of sodium dodecylbenzenesulfonate (anionic surfactant) was used in place of sodium lauriminodipropionate. The properties of the de-consolidated slurry are shown in table 4.

Comparative example 3

The combined catalytic cracking slurry processing was carried out as in example 2, except that cetyltrimethylammonium bromide (cationic surfactant) was used in the same weight amount instead of sodium lauriminodipropionate. The properties of the de-consolidated slurry are shown in table 4.

Comparative example 4

The catalytic cracking slurry combination processing was carried out as in example 2 except that no sodium lauriminodipropionate was added. The properties of the de-consolidated slurry are shown in table 4.

TABLE 4

Comparing the results of comparative examples 2-4 with those of example 2, it can be seen that the oil slurry de-solidification effect of the method of the present invention using the amphoteric surfactant is better.

The preferred embodiments of the present invention have been described above in detail, 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 method for combined processing of catalytic cracking slurry oil is characterized by comprising the following steps:

2. The method according to claim 1, wherein the amphoteric surfactant is at least one of an amino acid type amphoteric surfactant, a betaine type amphoteric surfactant, and an imidazoline type amphoteric surfactant.

3. The method of claim 2, wherein the amphoteric surfactant is at least one of sodium lauriminodipropionate, lauryl betaine, and imidazoline laurate quaternary.

4. The method according to claim 1, wherein the diluent is a mixed solution of a hydrocarbon solvent and an ester solvent.

5. The method according to claim 4, wherein the volume ratio of the hydrocarbon solvent to the ester solvent is 2-20: 1.

6. the method according to claim 4, wherein the volume ratio of the hydrocarbon solvent to the ester solvent is 5-10: 1.

7. the method of claim 1, 4, 5 or 6, wherein the diluent has a density of 0.8-0.95g/cm³。

8. The method according to any one of claims 1-6, wherein in step (1), the weight ratio of the catalytic cracking slurry oil, the amphoteric surfactant and the diluent is 1: 0.00005-0.0005: 0.2-3.

9. The method according to any one of claims 1-6, wherein in step (1), the weight ratio of the catalytic cracking slurry oil, the amphoteric surfactant and the diluent is 1: 0.0001-0.0003: 0.5-1.5.

10. The method according to any one of claims 1 to 6, wherein in the step (1), the weight ratio of the diluted oil slurry to the water is 1: 0.05-0.3.

11. The method according to any one of claims 1 to 6, wherein in the step (1), the weight ratio of the diluted oil slurry to the water is 1: 0.07-0.2.

12. The method according to any one of claims 1 to 6, wherein in step (1), the contacting conditions comprise: the temperature is 80-200 deg.C, and the pressure is 0.3-3 MPa.

13. The method according to any one of claims 1 to 6, wherein in step (1), the contacting conditions comprise: the temperature is 130 ℃ and 150 ℃, and the pressure is 1-1.8 MPa.

14. The method according to any one of claims 1 to 6, wherein the diluted slurry is preheated and then mixed with water, the preheating temperature being 50 to 150 ℃.

15. The method of any one of claims 1 to 6, wherein the fibre liquid membrane contactor is a cylinder.

16. The method according to any of claims 1-6, wherein the aspect ratio of the mass transfer spaces is 10-60: 1, the filling rate of the fiber filaments in the mass transfer space is 2-30 volume percent.

17. The method of any one of claims 1-6, wherein the fiber filaments are at least one of stainless steel filaments, carbon steel filaments, glass fiber filaments, polyamide fiber filaments, and polyester fiber filaments.

18. The method as claimed in any one of claims 1 to 6, wherein in the step (1), the liquid hourly space velocity of the diluted oil slurry fed is 5-60h based on the volume of the fiber filament^-1。

19. The method according to any one of claims 1 to 6, wherein in step (1), the step (b) is performed by a computerBased on the volume of the fiber yarns, the liquid hourly space velocity of the diluted oil slurry feeding is 10-20h^-1。

20. The method according to any one of claims 1 to 6, wherein in the step (2), the separation of the oil, water and solid phases is carried out by means of sedimentation and filtration, and the sedimentation time is 0.5 to 3 hours.

21. The process of any one of claims 1-6, wherein in step (3), the hydrotreating conditions comprise: the temperature is 300-450 ℃, the pressure is 10-20MPa, and the volume space velocity is 0.5-5h^-1。

22. The method of any of claims 1-6, wherein the method further comprises: returning the diesel fraction obtained in the distillation process of step (4) to step (1) as at least part of the diluent.