CN116731746A

CN116731746A - Method for separating diesel oil from heavy oil suspension bed hydrocracking product cold high-separation oil

Info

Publication number: CN116731746A
Application number: CN202310828045.7A
Authority: CN
Inventors: 何巨堂; 何艺帆; 马策旻; 刘湘扬; 王嘉恺
Original assignee: Luoyang Ruihua New Energy Technology Development Co ltd
Current assignee: Luoyang Ruihua New Energy Technology Development Co ltd
Priority date: 2023-07-07
Filing date: 2023-07-07
Publication date: 2023-09-12

Abstract

The method for separating diesel oil from cold high-separation oil of heavy oil suspension bed hydrocracking products comprises the steps of separating hot high-separation oil and cold high-separation oil from heavy oil suspension bed hydrocracking reaction products through a hot high-pressure separation process and a cold high-pressure separation process; the flash slurry obtained after the hot high-pressure oil separation and depressurization flash evaporation is separated into slurry depressurization flash vapor and slurry depressurization flash liquid after depressurization; the slurry decompression flash steam enters a rectification process to separate narrow distillate; the low-grade medium-temperature heat is recovered as a latent heat source of evaporation by reducing the evaporation temperature of the diesel by utilizing negative pressure, so that the system can be greatly simplified and the investment can be reduced.

Description

Method for separating diesel oil from heavy oil suspension bed hydrocracking product cold high-separation oil

Technical Field

The invention relates to a method for separating diesel oil from heavy oil suspension bed hydrocracking products in a cold high-separation mode, wherein the heavy oil suspension bed hydrocracking reaction products are separated into hot high-separation oil and cold high-separation oil through a hot high-pressure separation process and a cold high-pressure separation process; the flash slurry obtained after the hot high-pressure oil separation and depressurization flash evaporation is separated into slurry depressurization flash vapor and slurry depressurization flash liquid after depressurization; the slurry decompression flash steam enters a rectification process to separate narrow distillate; the bottom oil obtained by separating at least part of light hydrocarbon from the material flow obtained after the pressure reduction of the cold high-pressure oil separation enters the separation process of slurry pressure reduction flash steam and vapor phase containing diesel components to evaporate the diesel components, and the diesel is condensed in the subsequent fractionation process, so that a special diesel evaporation heat source can be reduced or even cancelled, namely the high-temperature heat energy consumption can be reduced, the negative pressure is utilized to reduce the evaporation temperature of the diesel, the low-grade middle-temperature heat is recovered as the evaporation latent heat source, the system can be greatly simplified, and the investment can be reduced; the thermal high-pressure separation process of the thermal high-pressure separated gas can be set to obtain thermal high-pressure separated oil which is combined with separation and recovery.

Background

The invention relates to a separation method of oil generated in a heavy oil suspension bed hydrocracking reaction process, in particular to a method for separating diesel oil from a heavy oil suspension bed hydrocracking product by cooling and high separation.

The heavy oil suspension bed hydrocracking generated oil contains diesel oil component, and can separate diesel oil boiling range fraction or mixed fraction of diesel oil and naphtha or mixed fraction of diesel oil and wax oil according to the requirement.

The properties of the feedstock oil during a typical heavy oil suspension bed hydrocracking reaction are shown in Table 1.

TABLE 1 raw oil quality during typical heavy oil suspension bed hydrocracking reaction

Project	Vacuum residuum 1	Remarks
			Specific gravity (20 ℃ C.), g/cm ³	1.03
S content, wt%	4.9
			N content, wppm	5699
Carbon residue, wt%	26.57
			Ni content, wppm	70.7
V content, wppm	221.65
			Cl content, ppm	/
Kinematic viscosity (100 ℃ C.) mm ² /s	11300
			ASTM D1160 distillation range, DEG C
Initial point of distillation	440
			10％	568
50％	684
			90％	1095
End point of distillation	1190

Typical product distributions for a typical heavy oil suspension bed hydrocracking reaction process are shown in table 2.

TABLE 2 typical product distribution for typical heavy oil suspension bed hydrocracking reaction process

The following describes an existing process for cold high separation of oil from diesel fuel from heavy oil suspension bed hydrocracking products, generally comprising the steps of:

(1) in the heavy oil suspension hydrocracking reaction process R10, a reaction raw material which mainly consists of hydrocarbon components with the conventional boiling point higher than 530 ℃ and contains asphaltene, namely a hydrocarbon raw material R10F, is subjected to heavy oil suspension hydrocracking reaction containing heavy oil suspension hydrocracking reaction in the presence of hydrogen and a heavy oil suspension hydrocracking catalyst, and the heavy oil suspension hydrocracking reaction R10R is converted into a heavy oil suspension hydrocracking reaction product R10P;

(2) In the hot high-pressure separation process S110, a material flow based on a heavy oil suspension bed hydrocracking reaction product R10P is separated into hot high-pressure gas S110V and hot high-pressure oil S110L;

in the thermal high pressure separation process S110, the vapor stream, which is finally converted to the thermal high pressure gas S110V, is oil washed with or without the wash oil feed S110-WF to remove a portion of the heavy hydrocarbons in the gas;

in the thermal high-pressure separation process, hydrogen-rich gas is used or not used for stripping the liquid-phase material flow which is finally converted into thermal high-fraction oil, so as to inhibit coking of the liquid-phase material flow and remove light components;

(3) in the high-pressure separation process S120, a material flow based on the hot high-pressure gas S110V is separated into a high-temperature gas S120V and a high-pressure oil S120L;

the gas phase material flow finally converted into the high-temperature separated gas S120V can be subjected to oil washing in the high-temperature and high-pressure separation process by using or not using the hydrocarbon oil material S120-WF so as to remove part of heavy hydrocarbon in the gas;

(4) in the thermal low-pressure separation process S210, the material flow based on the thermal high-pressure separation oil S110L is separated into a thermal low-pressure separation gas S210V and a thermal low-pressure separation oil S210L after depressurization;

the thermal low pressure separation process S210 comprises a 1-stage separation process or comprises a 2-stage or multi-stage sub-separation process operated in series;

when the thermal low-pressure separation process S210 includes a 2-stage or multi-stage sub-separation process including a series operation, the upper-stage thermal low-pressure sub-separation process bottom oil generated in the upper-stage thermal low-pressure sub-separation process of the thermal low-pressure separation process S210 is depressurized and then enters the lower-stage thermal low-pressure sub-separation process of the thermal low-pressure separation process S210 to be separated into a lower-stage thermal low-pressure sub-separation process separation gas and a lower-stage thermal low-pressure separation bottom oil;

The thermal low pressure separation process S210 comprises or does not comprise a chilled stabilization process S210-HX based on a hot high-split oil stream; cooling and stabilizing S210-HX of the material flow based on the heat high-pressure oil, and entering a flash separation process after the material flow based on the heat high-pressure oil is cooled and stabilized;

in the thermal low pressure separation process S210, the vapor stream that is ultimately converted to the thermal low pressure gas fraction S210V is oil washed, with or without the wash oil feed S210-WF, to remove a portion of the heavy hydrocarbons in the vapor stream;

separating the material flow after the pressure reduction of the hot high-pressure oil into hot high-pressure oil pressure reduction flash steam and hot high-pressure oil pressure reduction flash liquid;

the hot high-pressure oil-separation depressurization flash liquid is subjected to steam stripping process or not to evaporate hydrocarbon oil steam to obtain hot low-pressure oil S210L;

(5) in the pre-flash tower system C3101, the hot low-pressure gas S210V is separated into pre-flash tower top gas, pre-flash tower top oil and pre-flash tower bottom oil;

typically, the pre-flash column overhead gas, consisting essentially of hydrogen, conventional gas hydrocarbons, naphtha components, contains only a small amount of light diesel components;

typically, the pre-flash tower overhead consists essentially of conventional gaseous hydrocarbons, naphtha components, diesel components, containing only small amounts of light wax oil components;

Usually, the bottom oil of the pre-flash tower mainly comprises a diesel component and a wax oil component, and contains a small amount of naphtha component and a small amount of wax oil component;

(6) in the slurry decompression separation process C3121, the material flow based on the hot low-pressure oil is decompressed and then separated into slurry decompression flash steam and slurry decompression flash liquid under the condition that the operating pressure is negative pressure;

the slurry vacuum flash steam enters a slurry vacuum flash steam separation process to separate 2 or more narrow distillates (which may contain diesel distillate products);

evaporating at least a part of wax oil components from the slurry vacuum flash liquid through or without a steam stripping process to obtain vacuum separation process base oil SHC-VR;

the presence or absence of a stream based in part on the base oil of the pressure-reducing separation process as cycle oil R-SHC-VR, the cycle reaction of the heavy oil removal suspension bed hydrocracking reaction process R10, the ratio of the weight flow rate of the cycle oil R-SHC-VR to the weight flow rate of the reaction raw material R10F being referred to as the cycle ratio K100, K100 being generally from 0.40 to 2.5, generally from 0.70 to 1.80, preferably from 1.00 to 1.50;

(7) in the cold high-pressure separation process S130, the normal temperature high-pressure gas is mixed with washing water and then separated into cold high-pressure gas S130V, cold high-pressure oil S130L and cold high-pressure water S130W;

(8) In the cold low pressure separation process S230, the cold high-pressure oil is separated into cold low-pressure gas S230V and cold low-pressure oil S230L after depressurization;

(9) fractionating diesel oil fraction from the cold low-pressure separated oil in a positive pressure fractionation system C3301;

the positive pressure fractionation system C3301 refers to the fractionation column operating pressure of the positive pressure fractionation system C3301 being higher than atmospheric pressure;

because the cold low-pressure oil contains light wax oil, diesel oil, naphtha, normal gas hydrocarbon (carbon 1 hydrocarbon to carbon 4 hydrocarbon), hydrogen sulfide, water and hydrogen, the process of fractionating the diesel oil necessarily at least comprises the separation of Chai Youzu from the wax oil component and the separation of the diesel oil component from the naphtha component, thus, in combination with the separation of the naphtha and the normal gas hydrocarbon, a plurality of separation processes exist, any suitable type of process can be selected according to the needs, and at least the following typical processes are generally adopted:

the first typical flow is that naphtha and normal gas hydrocarbon are separated firstly, namely normal gas hydrocarbon is separated firstly through a debutanizer to obtain debutanizer bottom oil, and then the debutanizer bottom oil is fractionated into naphtha, diesel oil and wax oil in a normal pressure tower or a system consisting of the normal pressure tower and a normal pressure tower side line diesel oil light component removal tower;

The second typical flow is that the separation of naphtha and normal gas hydrocarbon is finished firstly, namely the normal gas hydrocarbon is separated firstly through a debutanizer to obtain debutanizer bottom oil, then the debutanizer bottom oil is separated into naphtha and naphtha-removed tower bottom oil through a naphtha-removed tower, and then the naphtha-removed tower bottom oil is fractionated into diesel oil and wax oil in a diesel fractionating tower;

the third typical flow is that naphtha and normal gas hydrocarbon are not separated, namely low-fraction oil enters a naphtha removing tower to separate naphtha and components with lower boiling points, so as to obtain naphtha removing tower bottom oil, and then the naphtha removing tower bottom oil is fractionated into diesel oil and wax oil;

the fourth typical flow is that naphtha and normal gas hydrocarbon are not separated, and the low-fraction oil is fractionated into atmospheric tower top gas, atmospheric tower top oil, diesel oil at the bottom of the diesel side stripper and atmospheric tower bottom wax oil by adopting an atmospheric tower and diesel side stripper combined fractionation system;

the four positive pressure fractionation systems C3301 for fractionating the diesel fraction from the cold low-pressure separated oil are all independent diesel fractionation systems.

The material flow based on the cold low-fraction oil enters a fractionating system for separating diesel oil, after the material flow based on the cold low-fraction oil is subjected to heat exchange and temperature rising, the conventional gas and light naphtha components are separated or not, and then the material flow based on the cold low-fraction oil, which contains the diesel oil components and the wax oil components, enters a fractionating tower system for separating the diesel oil after being heated by a heating furnace, so that the diesel oil fraction, the wax oil fraction and the light hydrocarbon material flow with the boiling point lower than that of the diesel oil are obtained.

Because the separation (evaporation) temperature of diesel oil components and wax oil components is usually higher under the positive pressure condition of the positive pressure fractionation system C3301, the cold low-fraction oil-based material flow is required to be heated to 290-330 ℃, namely a large amount of high-temperature heat energy (the heat source temperature is at least 320-360 ℃) is required to be input into the material to be evaporated, but the high-temperature heat energy (the heat source temperature is at least 320-360 ℃) which is convenient to use is difficult to find in the hydrocracking reaction process of the heavy oil suspension bed and the fractionation process of the generated oil separation;

in the low-temperature and low-pressure separation step S220, the material flow based on the high-temperature separated oil S120L is separated into low-temperature separated gas S220V and low-temperature separated oil S220L after depressurization;

the normal temperature and low pressure separation step S220 and the thermal low pressure separation step S210 are combined, namely, the material flow based on the temperature and high oil separation step S120L is depressurized and then enters the thermal low pressure separation process S210 to be separated into temperature and low oil separation step S220V and temperature and low oil separation step S220L, the temperature and low oil separation step S220V enters the thermal low oil separation step S210V, and the temperature and low oil separation step S220L enters the thermal low oil separation step S210L; or, the material flow after the material flow based on the temperature high-pressure separation oil S120L is depressurized is mixed with the material flow after the heat high-pressure separation oil is depressurized, and then the mixture enters a heat low-pressure separation process S210;

the warm low pressure separation process S220 may comprise a 1-stage separation process or comprise a 2-stage or multi-stage separation process that is operated in series;

When the low-temperature and low-pressure separation process S220 includes 2 or more stages of sub-separation processes operated in series, the bottom oil of the upper-stage low-temperature and low-pressure sub-separation process generated in the upper-stage low-temperature and low-pressure sub-separation process of the low-temperature and low-pressure separation process S220 is depressurized and then enters the lower-stage low-temperature and low-pressure sub-separation process of the low-temperature and low-pressure separation process S220 to be separated into separation gas of the lower-stage low-temperature and low-pressure sub-separation process and bottom oil of the lower-stage low-temperature and low-pressure separation process;

typically, the low temperature separated gas S220V enters the pre-flash column system C3101;

typically, the low temperature oil fraction S220L enters slurry depressurization separation process C3102;

the hot high-pressure oil S110L can be divided into a first branch hot high-pressure oil S110L-1 and a second branch hot high-pressure oil S110L-2;

the first branch heat high-pressure oil S110L-1 is used for separating residual oil obtained after hydrocarbon components with the conventional boiling point lower than 540 ℃ are separated, and part or all of the residual oil is used as external throwing unconverted residual oil;

the second branch heat high-pressure oil S110L-1 is used for separating residual oil obtained after hydrocarbon components with the conventional boiling point lower than 540 ℃ are separated, and part or all of the residual oil is used as circulating oil R-SHC-VR to be used for carrying out a heavy oil removal suspension bed hydrocracking reaction in the R10 circulating reaction process;

the hydrocarbon component with the conventional boiling point lower than 540 ℃ separated from the first branch thermal high-fraction oil S110L-1 is separated from the hydrocarbon component with the conventional boiling point lower than 540 ℃ separated from the second branch thermal high-fraction oil S110L-1 in a combined way.

The above-mentioned several methods for separating diesel oil from cold high-pressure separation oil are all separation methods for naphtha, diesel oil and wax oil components by using special distillation tower system, and the process for separating diesel oil from cold high-pressure separation oil and the process for separating diesel oil from hot high-pressure separation oil are respectively implemented in 2 mutually independent systems, and have the defects that since the flash evaporation process (including hot high-pressure separation process, high-pressure separation process and cold high-pressure separation process) of hydrocracking reaction product of heavy oil suspension bed is implemented under high pressure, separation definition is limited, clear separation of components contained in hot high-pressure separation oil, hot high-pressure separation oil and cold high-pressure separation oil can not be implemented, and cold high-pressure separation oil containing only small quantity of wax oil component (usually wax oil content is 7-15% by weight) or pressure-reducing flash oil thereof has to be separated in a fractionating tower system whose pressure is usually 0.1-0.3 MPaG (gauge pressure), and the disadvantage is that it is undergone a strong endothermic process whose vaporization rate is up to 90-98% by weight:

(1) the special diesel evaporation heat source is needed to consume a large amount of high-temperature heat energy, and when the middle-temperature heat energy is insufficient, the heating furnace is needed to consume fuel to provide high-temperature heat, and the heat exchange process has complex system and high investment; the cold high-fraction oil or the depressurization flash oil needs to be preheated to 290-330 ℃; because of the vaporization heat of diesel oil which consumes a great amount of heat, correspondingly, a heat recovery process which forms a great amount of heat is also needed, and a great amount of low temperature emitted to the environment is inevitably needed to form heat loss, so the energy consumption is high;

(2) The independent heat supply system of the diesel vaporization heat and the independent fractionating tower system lead to complex system and high investment;

(3) the heat sink effect of cold source materials of cold high-pressure separated oil or pressure-reduced flash oil is not fully exerted, and the potential recyclable medium-temperature heat recovery rate is reduced.

For the diesel component vaporization process set at 150t/h, the unit weight vaporization latent heat is estimated according to 75kcal/kg, 11.25MMkcal/h is needed for only one vaporization latent heat, but in practice, the fractionation process of diesel and wax oil also has the necessary vaporization latent heat of reflux liquid required by internal reflux liquid beyond the above heat value, and the heat is also needed to be recovered and partially transferred to the environment when being transferred into the condensation heat of the diesel condensation process with lower temperature, which relates to heat supply of a heat exchanger, heat supply of a heating furnace, heat recovery of a heat exchanger and other systems.

In general, the high pressure separation process of the heavy oil suspension bed hydrocracking reaction product R10P is provided with a hot high pressure separation process S110, a high pressure separation process S120, and a cold high pressure separation process S130, and from the viewpoint of separation accuracy, since the cold high-pressure oil contains 70 to 85% by weight of diesel oil components and only 5 to 10% by weight of wax oil components, it is difficult to clearly separate the diesel oil components from the wax oil components in the positive pressure fractionation system C3301, which generally results in a wax oil product containing a large amount of diesel oil components.

In order to solve the technical drawbacks of the above-mentioned fractionation process for separating diesel oil from cold high-fraction oil, theoretical analysis shows that improvement is needed in two aspects, namely, the heat release process of condensation of the vapor phase material to be condensed, especially the high boiling point vapor phase material (wax oil or heavier boiling point component) is preferably found to be combined with the heat release process of evaporation of the diesel oil component of the cold low-fraction oil-based mixed material containing the diesel oil component and the wax oil component to form a combined distillation process, thereby simplifying the flow, reducing the consumption of an independent heat source and reducing the operation cost, and in one way, the flash pressure reducing vapor phase stream of the wax oil component to be condensed under a huge amount of negative pressure condition is needed to be found, and the flash pressure reducing vapor phase stream of the wax oil component to be condensed based on the slurry vapor phase existing in the slurry pressure reducing separation process is the above-mentioned characteristics.

Flow simulation results and industrial production data indicate that typically, 50-70% of the diesel component of the heavy oil suspension bed hydrocracking product enters the cold tall oil and almost 80-90% of the wax oil component enters the slurry pressure reducing flash steam of the hot tall oil slurry pressure reducing separation process C3121, and thus, typically, the latent heat of vaporization of the diesel component in most or all of the cold tall oil can be provided by the condensation process of the wax oil component of the hot tall oil slurry pressure reducing flash steam of the hot tall oil slurry pressure reducing separation process C3121. And under the negative pressure condition, the diesel oil component and the wax oil component are easy to realize clear separation, and the yield of the diesel oil product can be improved.

The basic idea of the invention has been proposed so far: the method for separating diesel oil from cold high-separation oil of heavy oil suspension bed hydrocracking products comprises the steps of separating hot high-separation oil and cold high-separation oil from heavy oil suspension bed hydrocracking reaction products through a hot high-pressure separation process and a cold high-pressure separation process; the flash slurry obtained after the hot high-pressure oil separation and depressurization flash evaporation is separated into slurry depressurization flash vapor and slurry depressurization flash liquid after depressurization; the slurry decompression flash steam enters a rectification process to separate narrow distillate; the bottom oil obtained by separating at least part of light hydrocarbon from the material flow obtained after the pressure reduction of the cold high-pressure oil separation enters the separation process of slurry pressure reduction flash steam and vapor phase containing diesel components to evaporate the diesel components, and the diesel is condensed in the subsequent fractionation process, so that a special diesel evaporation heat source can be reduced or even cancelled, namely the high-temperature heat energy consumption can be reduced, the negative pressure is utilized to reduce the evaporation temperature of the diesel, the low-grade middle-temperature heat is recovered as the evaporation latent heat source, the system can be greatly simplified, and the investment can be reduced; the thermal high-pressure separation process of the thermal high-pressure separated gas can be set to obtain thermal high-pressure separated oil which is combined with separation and recovery; further, the diesel-rich liquid enters a diesel light component removing tower and is separated into a diesel light component removing tower top gas rich in naphtha components and a diesel light component removing tower bottom oil lean in naphtha components, and a steam stripping method or a tower bottom reboiler method can be adopted.

In order to allow for the top vacuum 7X of the slurry pressure reduction flash fractionation process C3121 to be operated under conventional suitable conditions (to minimize the load on the vacuum), it is desirable to control the amount of non-condensable gas components contained in the feed gas to the vacuum 7X so that the low boiling point component content of the cold high-fraction oil-based stream entering the slurry pressure reduction flash fractionation process C3121 is controlled so as to be less than or as little as possible, preferably no conventional gaseous hydrocarbons, and preferably no hydrocarbons having a conventional boiling point of less than 120 ℃ or a conventional boiling point of less than 180 ℃, i.e., reasonable process objectives require removal of at least light naphtha components after depressurization of the cold high-fraction oil before entering the slurry pressure reduction flash fractionation process C3121 for component fractionation. The extent of removal of the low boiling point components from the cold high-fraction oil stream is selected as desired, depending on the cold high-fraction oil composition and the naphtha content of the light-fraction oil, and can remove substantially all or most of the naphtha component or only the light naphtha component, so that the naphtha component contained in the cold high-fraction oil-removed naphtha component is separated during the slurry vacuum flash fractionation.

The invention can be combined with CN115975675A, which is an ideal separation method for stabilizing, saving energy and improving the heat energy quality of the waste heat of the material flow, and the invention can greatly improve the quality of the related heat energy and is convenient for economic recycling because the viscosity is reduced, the condensation point is reduced, the heat condensation speed is reduced to the bottom, the scaling speed of a heat exchanger is reduced and the heat transfer speed is improved.

The invention aims to provide a combined distillation method for separating diesel oil from heavy oil suspension bed hydrocracking cold high-pressure oil, which can simplify the flow, reduce the investment and reduce the energy consumption.

The invention can also combine the oil flow containing diesel oil component, wax oil component and naphtha component separated by the fractionating pre-flash tower system.

The invention can also combine to separate high-temperature oil.

For the process of separating diesel oil from heavy oil suspension bed hydrocracking cold high-pressure oil, the invention has the advantages that:

(1) The special diesel evaporation heat source is reduced or canceled, namely, a large amount of high-temperature heat energy is not required to be consumed, a heating furnace is not required to be arranged to consume fuel to provide high temperature when the medium-temperature heat is fully recovered, and the heat exchange process is simple in system and low in investment;

meanwhile, a condensing heat transfer process of transferring the special diesel evaporation heat into a diesel condensing process with lower temperature is avoided, and the latter needs a heat exchange system to recycle or transfer heat into the environment, so that corresponding system investment and energy loss are saved;

the temperature difference of the heat supply side in the diesel evaporation process is large (negative pressure operation is beneficial to reducing the evaporation heat temperature so as to reduce the cost and improve the medium temperature heat recovery rate) and the heat energy difference carried by the fractionated product is large (negative pressure operation is beneficial to reducing the heat energy carried by the product diesel so as to reduce the energy consumption) as compared with the evaporation temperature of the diesel fraction with the same composition under the pressure of 0.004-0.025 MPa and the evaporation temperature of the diesel fraction under the pressure of 0.1-0.25 MPa; ,

(2) an independent fractionating tower system is omitted, a combined preheating and combined fractionating system is formed, and the system is simple and has low investment;

(3) the method can fully exert the heat trap effect of cold source materials of cold high-fraction oil or depressurization flash oil thereof, can improve the medium-temperature heat recovery rate, particularly, when the wax oil component content in slurry depressurization flash steam is low and the condensation heat is insufficient to gasify the diesel oil component of the cold high-fraction oil or depressurization flash oil thereof, a method of arranging an intermediate vaporizer can be adopted, the circulating oil containing the diesel oil component and the wax oil component discharged from a depressurization tower or even diesel oil liquid is pressurized and then subjected to heat exchange with medium-temperature heat material flow (such as residual oil at the bottom of the depressurization tower) and then the depressurization part is gasified and returned to the depressurization tower, the diesel oil component is gasified, the wax oil component is reduced in temperature, and the unvaporized wax oil component is mixed with liquid in a fractionating tower and then is circularly heated along with circulating oil, so that the aim of converting the medium-temperature heat into the diesel oil gasification latent heat is fulfilled; because the gasification is carried out in a decompression environment, the gasification point temperature of the circulating oil is very low, for example, can be 150-190 ℃, and is reduced by about 140 ℃ compared with the preheating temperature of 290-330 ℃ in an independent fractionation scheme, the medium-temperature heat recovery rate can be greatly improved, the medium-temperature heat value (partially replacing the high-temperature heat caused by fuel consumption) is improved, and the investment of a heating furnace of a corresponding part is saved;

(4) The method is particularly suitable for the combined separation of the atmospheric residuum based on crude oil, adopts a heavy oil suspension bed hydrogenation conversion method, and the atmospheric residuum is directly mixed with hot high-pressure oil after depressurization and enters a fractionation process after being cooled, and because the wax oil component in the slurry vacuum flash steam contains both the wax oil of the hydrocracking product of the residuum suspension bed and the straight-run wax oil component in the atmospheric residuum, the quantity of the wax oil component is huge, and a sufficient gasification heat source can be provided for the evaporation of the cold high-pressure oil and the diesel oil in the distillate oil of the pre-flash tower.

The method of the invention is not reported.

Therefore, the first purpose of the invention is to provide a method for separating diesel oil from heavy oil suspension bed hydrocracking hot high-pressure oil and cold high-pressure oil, which is a universal method, and can greatly simplify the flow, greatly reduce the investment and greatly reduce the energy consumption.

The second purpose of the invention is to provide a separation method for hydrocracking self-heavy oil suspension bed to generate oil, and comprehensively separate all diesel oil and wax oil containing streams.

Disclosure of Invention

The invention discloses a method for separating diesel oil from heavy oil suspension bed hydrocracking products in a cold high-separation way, which comprises the following steps:

in a heavy oil suspension bed hydrocracking reaction process R10, a hydrocarbon raw material R10F mainly comprising hydrocarbon components with a conventional boiling point higher than 530 ℃ and containing at least a part of asphaltenes is subjected to a heavy oil suspension bed hydrocracking reaction R10R containing heavy oil suspension bed hydrocracking reaction in the presence of hydrogen and a heavy oil suspension bed hydrocracking catalyst to be converted into a heavy oil suspension bed hydrocracking reaction product R10P;

Secondly, in a hot high-pressure separation process S110, separating a material flow based on a heavy oil suspension bed hydrocracking reaction product R10P into hot high-pressure gas S110V and hot high-pressure oil S110L;

in the thermal high pressure separation process S110, the gas phase stream, which is finally converted to the thermal high-pressure gas S110V, is oil washed with or without the use of the wash oil feed S110-WF;

in the thermal high pressure separation process S110, the liquid phase stream, which is finally converted to a thermal high separation oil, is stripped with or without hydrogen-rich gas;

third, in the thermal low-pressure separation process S210, the material flow based on the thermal high-pressure separation oil S110L is separated into a thermal low-pressure separation gas S210V and a thermal low-pressure separation oil S210L after depressurization;

the thermal low pressure separation process S210 comprises or does not comprise a chilled stabilization process S210-HX based on the stream of the thermal high-pressure separation oil S110L; cooling and stabilizing the material flow based on the heat high-pressure oil S110L to obtain S210-HX, cooling the material flow based on the heat high-pressure oil S110L to realize heat stabilization, and then entering a flash separation process;

In the thermal low pressure separation process S210, the vapor stream that is finally converted to the thermal low partial gas S210V is oil washed with or without the wash oil feed S210-WF;

the hot high-pressure oil-separation depressurization flash liquid is subjected to steam stripping or not to steam hydrocarbon steam to become hot low-pressure oil S210L;

fourthly, in a slurry decompression separation process C3121, the material flow based on the thermal low-pressure oil S210L is decompressed and then separated into slurry decompression flash steam and slurry decompression flash liquid under the condition that the operating pressure is negative pressure;

the slurry decompression flash steam enters a slurry decompression flash steam separation process to separate 2 or more narrow distillate oil;

the presence or absence of a stream based in part on the pressure-reduced separation process bottoms SHC-VR as cycle oil R-SHC-VR, the ratio of the weight flow rate of cycle oil R-SHC-VR to the weight flow rate of hydrocarbon feedstock R10F being referred to as cycle ratio K100, to the heavy oil suspension bed hydrocracking reaction process R10 cycle reaction;

fifthly, in a cold high-pressure separation process S130, separating a stream based on the high-pressure separation gas S110V into cold high-pressure separation gas S130V and cold high-pressure separation oil S130L;

In the cold high pressure separation process S130, the stream based on high-split gas S110V is washed with or without wash water; when washing the material flow based on the high-pressure gas S110V by using washing water, the material flow based on the high-pressure gas S110V is mixed with the washing water and then separated into cold high-pressure gas S130V, cold high-pressure oil S130L and cold high-pressure water S130W;

at least a part of hydrogen-rich gas based on the cold high-pressure gas S130V is used as circulating hydrogen RH to return to the heavy oil suspension bed hydrocracking reaction process R10 for recycling;

removing at least a part of hydrocarbon components with conventional boiling points lower than 180 ℃ from a stream based on cold high-fraction oil S130L in a separation system KC3301 to obtain base oil serving as first diesel rich oil containing diesel components and wax oil components;

the separation process for obtaining diesel from the first diesel rich fuel is characterized in that: at least a portion of the stream containing diesel components, wax oil components, based on the first diesel rich stream enters slurry depressurization separation process C3121, contacts the stream based on thermal low-split oil S210L and vaporizes the diesel components in the first diesel rich stream, enters the vapor phase stream based on slurry depressurization flash vapor, and then the diesel component vapor from the first diesel rich stream is condensed into a first diesel liquid.

In the invention, generally, the heavy oil suspension bed hydrocracking catalyst is a solid particle catalyst in the heavy oil suspension bed hydrocracking reaction process R10, at least comprises Mo element, and the main body working form of the Mo element in the heavy oil suspension bed hydrocracking reaction process R10 is M0S2;

in the heavy oil suspension bed hydrocracking reaction process R10, the circulating oil R-SHC-VR is mixed with the hydrocarbon raw material R10F or the intermediate conversion product of the hydrocarbon raw material R10F;

fourthly, in the slurry decompression separation process C3121, taking a material flow based in part on the bottom oil of the decompression separation process as circulating oil R-SHC-VR, and carrying out a cyclic reaction in the heavy oil removal suspension bed hydrocracking reaction process R10;

removing at least a part of hydrocarbon components with conventional boiling points lower than 180 ℃ from a stream based on cold high-fraction oil S130L in a separation system KC3301 to obtain first diesel-rich oil mainly composed of diesel components and wax oil components;

the separation process for obtaining diesel from the first diesel rich fuel is characterized in that: at least a portion of the stream containing the diesel component, the wax oil component, based on the first diesel rich fraction, enters the separation process of the slurry pressure reduction flash steam of the slurry pressure reduction separation process C3121, contacts the vapor phase stream based on the slurry pressure reduction flash steam and vaporizes the diesel component in the first diesel rich fraction, enters the vapor phase stream based on the slurry pressure reduction flash steam, and then the diesel component steam from the first diesel rich fraction is condensed into the first diesel liquid.

In the present invention, in general, in a separation system KC3301, in a first diesel light component removal process, a first diesel liquid is separated into a first diesel light component removal process gas rich in naphtha component and a first diesel light component removal process base oil lean in naphtha component;

typically, at least a portion of the first diesel light ends process vapor is returned to the column section of the fractionation column of slurry pressure reduction separation process C3121 above the discharge of the first diesel liquid.

In the present invention, in general, in the high-pressure separation process S120, a stream based on the hot high-pressure gas S110V is separated into the hot high-pressure gas S120V and the high-pressure oil S120L;

in the high-pressure separation process S120, the gas-phase material which is finally converted into the temperature and high-pressure separated gas S120V is subjected to oil washing by using or not using the washing oil material S120-WF;

in the low-temperature and low-pressure separation process S220, the material flow based on the high-temperature separated oil S120L is separated into low-temperature separated gas S220V and low-temperature separated oil S220L after depressurization;

the low-temperature separated oil S220L enters a slurry decompression separation process C3121;

the warm low pressure separation process S220 comprises a 1-stage separation process or comprises a 2-stage or multi-stage sub-separation process that is operated in series;

Removing at least a part of hydrocarbon components with conventional boiling points lower than 180 ℃ from a stream based on cold high-fraction oil S130L in a separation system KC3301 to obtain first diesel-rich oil mainly composed of diesel components and containing wax oil components;

the separation process for obtaining diesel from the first diesel rich fuel is characterized in that: at least a portion of the stream based on the diesel component, wax oil component of the first diesel-rich stream enters the separation process of the slurry pressure reduction flash steam of slurry pressure reduction separation process C3121, contacts the vapor phase based on the diesel component of the slurry pressure reduction flash steam and vaporizes the diesel component of the first diesel-rich stream, enters the vapor phase stream based on the slurry pressure reduction flash steam, and then the diesel component vapor from the first diesel-rich stream is condensed to a first diesel liquid.

In the present invention, in general, the warm low pressure separation process S220 is performed in combination with the hot low pressure separation process S210;

the material flow based on the temperature high-pressure separation oil S120L is depressurized and then enters a thermal low-pressure separation process S210 to be separated into temperature low-pressure separation gas S220V and temperature low-pressure separation oil S220L, wherein the temperature low-pressure separation gas S220V enters the thermal low-pressure separation gas S210V, and the temperature low-pressure separation oil S220L enters the thermal low-pressure separation oil S210L; alternatively, the stream based on the high temperature oil fraction S120L after depressurization is mixed with the stream based on the high temperature oil fraction after depressurization to enter the thermal low pressure separation process S210.

In the present invention, generally, at least a portion of the naphtha component and the components having a lower boiling point are removed from the stream based on the cold high-fraction oil S130L in the separation system KC3301 to obtain a first diesel rich in wax oil component mainly composed of diesel components;

the separation system KC3301 is operated in a manner selected from one of the following:

(1) removing more than 90% by weight of the naphtha component having a boiling point below 130 ℃;

(2) removing more than 50% by weight of the naphtha component;

(3) more than 95% by weight of the naphtha component is removed.

In general, the operating conditions of the steps of the present invention are as follows:

the method comprises the steps that in a heavy oil suspension bed hydrocracking reaction process R10, a heavy oil suspension bed hydrocracking catalyst is a solid particle catalyst and at least comprises Mo element, and the main working form of the Mo element in the heavy oil suspension bed hydrocracking reaction process R10 is M0S2;

hydrocarbon feedstock R10F having a conventional boiling point greater than 530 ℃ and a hydrocarbon component weight concentration greater than 70% while satisfying at least one of the following conditions:

(1) asphaltene weight concentration greater than 12%;

(2) the Kangshi carbon residue value is higher than 16%;

(3) the weight content of organic sulfur is higher than 0.5%;

(4) the organic nitrogen weight content is higher than 0.15%;

(5) the weight content of the organic metal is higher than 0.015%;

In the heavy oil suspension bed hydrocracking reaction process R10, the total hydrocracking total weight conversion rate of the hydrocarbon components with the conventional boiling point higher than 530 ℃ in the hydrocarbon raw material R10F is 80-98 percent;

separating the heavy oil suspension bed hydrocracking reaction product R10P in the heavy oil suspension bed hydrocracking reaction process R10 with or without processing to obtain a reduced pressure separation process base oil mainly composed of hydrocarbon components with normal boiling point higher than 530 ℃;

the operating conditions of the heavy oil suspension bed hydrocracking reaction process R10 are as follows: the temperature is 380-455 ℃ and the pressure is 8.0-25.0 MPa;

the operation conditions of the thermal high-pressure separation process S110 are as follows: the temperature is 380-455 ℃ and the pressure is 8.0-25.0 MPa;

the operating conditions of the thermal low pressure separation process S210 are: the temperature is 380-455 ℃ and the pressure is 0.20-2.00 MPa;

the thermal low pressure separation process S210 may comprise a 1-stage separation process or may comprise a 2-stage or multi-stage separation process operated in series;

the thermal low-pressure separation process S210 comprises or does not comprise a cooling stabilization process S210-HX of the thermal high-pressure oil or the material flow after the pressure reduction of the thermal high-pressure oil is cooled by 30-60 ℃, and then the material flow after the cooling stabilization enters a flash separation process;

the tower top operation pressure of the fractionating tower used in the slurry decompression separation process C3121 is 0.002-0.020 MPa absolute pressure;

The circulation ratio K100 is 0.40-2.5;

the operation conditions of the cold high-pressure separation process S130 are as follows: the temperature is 20-75 ℃ and the pressure is 8.0-25.0 MPa;

sixthly, in a separation system KC3301, obtaining naphtha which is mainly composed of diesel components and contains wax oil components and contains the first diesel rich in wax oil components, wherein the weight concentration of the naphtha and the lower boiling point components is lower than 15% by weight;

the separation process for obtaining diesel in the first diesel rich liquid yields a weight concentration of naphtha and lower boiling components of less than 5% by weight in the first diesel liquid.

In general, the operation conditions of the high-temperature and high-pressure separation process S120 according to the present invention are: the temperature is 285-400 ℃ and is 30-130 ℃ lower than the operation temperature of the thermal high-pressure separation process S110, and the pressure is 8.0-25.0 MPa;

the operating conditions of the low temperature pressure separation process S220 are: the temperature is 285-400 ℃ and the pressure is 0.20-2.00 MPa.

In general, in the slurry pressure reduction separation process C3121, the circulation ratio K100 is selected from one of the following conditions:

①≤0.80；

②0.80～1.20；

③1.20～1.60；

④1.60～2.50；

⑤≥2.50。

in the invention, in general, in a pre-flash tower C3101 system, a material flow based on hot low-pressure gas S210V enters the bottom of the pre-flash tower C3101 to flow upwards, is mixed with reflux liquid in the tower to be contacted, and is separated into pre-flash tower bottom oil C3101-BOTL and rising gas in the pre-flash tower C3101;

Ascending gas in the pre-flash tower C3101 passes through a mass transfer element in the pre-flash tower C3101 in an ascending manner and then is converted into tower top exhaust gas of the pre-flash tower C3101;

forming descending reflux liquid at the upper part of the pre-flash tower C3101 by condensing oil based on the gas discharged from the top of the pre-flash tower C3101 or circulating cooling oil at the top of the pre-flash tower C3101, and carrying out heat transfer and mass transfer with ascending gas in the pre-flash tower C3101;

based on the top exhaust gas of the pre-flash tower C3101, obtaining a gas-phase separation product of the top gas of the pre-flash tower C3101;

condensing oil based on the top discharge gas of the pre-flash tower C3101 and/or side-draw oil based on the pre-flash tower C3101 to obtain a light oil separation product of the pre-flash tower C3101;

the gas phase separation product at the top of the pre-flash tower C3101 mainly consists of hydrogen, conventional gas hydrocarbon and naphtha components, and does not contain or only contains a small amount of diesel components;

the pre-flash tower C3101 light oil separation product mainly comprises conventional gas hydrocarbon, naphtha component and diesel component, and does not contain or only contains a small amount of light wax oil component;

the bottom oil C3101-BOTL of the pre-flash tower mainly comprises a diesel oil component and a wax oil component.

the top exhaust gas of the pre-flash tower C3101 enters a top reflux tank of the pre-flash tower C3101 to be separated into top gas C3101-TOPV of the pre-flash tower and top oil C3101-TOPL of the pre-flash tower through a condensation cooling process;

the top gas C3101-TOPV of the pre-flash tower mainly comprises hydrogen, conventional gas hydrocarbon and naphtha components, and does not contain or only contains a small amount of light diesel components;

the top oil C3101-TOPL of the pre-flash tower mainly comprises conventional gas hydrocarbon, naphtha component and diesel component, and does not contain or only contains a small amount of light wax oil component;

the bottom oil C3101-BOTL of the pre-flash tower mainly comprises a diesel oil component and a wax oil component, and the bottom oil C3101-BOTL of the pre-flash tower mainly comprises the diesel oil component and the wax oil component.

In the invention, in general, a side light oil extraction port of the pre-flash tower C3101 is arranged at the upper section of the pre-flash tower C3101, and the side light oil of the pre-flash tower C3101 mainly consists of diesel oil components, does not contain or only contains a small amount of light wax oil components and contains naphtha components.

In the present invention, in general, the second side column is used in the process of removing the light component from the pre-flash column C3101 side light oil, and the pre-flash column C3101 side light oil is separated into the pre-flash column C3101 side light oil separation gas rich in the naphtha component, that is, the second side column overhead gas, and the pre-flash column C3101 side light oil separation liquid lean in the naphtha component, that is, the second side column bottom oil.

In the present invention, at least a part of the light oil separation vapor on the side line of the pre-flash column C3101 is returned to the column section of the pre-flash column C3101 located above the discharge port of the light oil on the side line of the pre-flash column C3101.

In the present invention, generally, streams C3101-BOTL-X, based on pre-flash column bottoms C3101-BOTL, enter slurry vacuum separation process C3121, enter vacuum fractionation column mass transfer elements where liquid phase feed hydrocarbon composition is similar, are mixed with the feed passing through the vacuum fractionation column mass transfer elements and contacted with vapor phase feed in the vacuum fractionation column to complete partial or complete vaporization of streams C3101-BOTL-X, and then the different boiling range fractions enter the separation process of slurry vacuum flash vapor into 2 or more narrow distillates separated.

In the present invention, generally, the mixed oil of the diesel oil component and the wax oil component separated in the slurry pressure-reducing separation process C3121 is used as the washing oil material S110-WF used in the thermal high pressure separation process S110 and/or the washing material S120-WF of the thermal high pressure separation process S120.

In the present invention, generally, the hydrocarbon oil composed of the main wax oil component separated in the slurry pressure reduction separation process C3121 is used as the washing oil material S210-WF used in the thermal low pressure separation process S210.

In general, at least a portion of the stream containing the diesel component, the wax oil component, based on the first diesel rich gas, enters the column section of the fractionation column used in the slurry pressure reduction separation process C3121 between the first diesel liquid outlet and the adjacent liquid outlet below the first diesel liquid outlet, and is mixed with the material flowing in the column section.

In general, at least a portion of the stream containing the diesel component, the wax oil component, based on the first diesel rich gas, enters the column section between the first diesel liquid discharge port and the adjacent liquid discharge port below the first diesel liquid discharge port of the fractionation column used in the slurry pressure reduction separation process C3121 and is used as the cooling stream for this column section.

In general, at least a portion of the stream containing the diesel component and the wax oil component, based on the first diesel-rich gas, is introduced into the column section between the first diesel liquid outlet and the adjacent liquid outlet below the first diesel liquid outlet of the fractionation column used in the slurry pressure reduction separation process C3121, and is used as the cooling stream in the uppermost portion of the column section.

In the present invention, in general, the circulating heat-removal oil 99L is discharged from the column section between the first diesel liquid discharge port of the fractionation column used in the slurry pressure-reducing separation process C3121 and the adjacent liquid discharge port below the first diesel liquid discharge port;

After heat exchange and temperature rise are carried out on the heat flow existing in the separation process of the circulating heat taking oil 99L and the heat high-pressure oil S110L, the heat flow returns to the slurry decompression separation process C3121 for recycling, and is used for the evaporation of diesel components.

after heat exchange and temperature rise are carried out on the heat flow existing in the separation process of the circulating heat taking oil 99L and the heat high-pressure oil S110L, the heat flow returns to the tower section between the first diesel oil liquid discharge port of the fractionating tower used in the slurry decompression separation process C3121 and the adjacent liquid discharge port below the first diesel oil liquid discharge port.

after heat exchange and temperature rise are carried out on the hot material flow existing in the separation process of the circulating heat-taking oil 99L and the hot high-pressure oil S110L, the hot material flow returns to the tower section between the first diesel oil liquid discharge port and the adjacent liquid discharge port below the first diesel oil liquid discharge port of the fractionating tower used in the slurry decompression separation process C3121, and is positioned at the lower part of the circulating heat-taking oil 99L.

In the invention, in general, in the slurry decompression separation process C3121, the circulating heat-taking oil 88L is taken out in the slurry decompression flash steam separation process;

after the heat exchange and temperature rise of the circulating heat-taking oil 88L and the hot stream existing in the separation process of the hot high-pressure oil S110L, the circulating heat-taking oil 88L returns to the slurry decompression separation process C3121 to realize the evaporation of at least a part of components to form circulating heat-taking oil 88L steam, and the circulating heat-taking oil 88L steam or the secondary steam formed by contacting with internal reflux liquid contacts with the stream based on the first diesel oil for the evaporation of diesel components in the stream based on the first diesel oil.

after heat exchange and temperature rising are carried out on the circulating heat-taking oil 88L and a hot stream existing in the separation process of the hot high-pressure oil S110L, the circulating heat-taking oil 88L returns to the slurry decompression separation process C3121 to realize evaporation of at least a part of components to form circulating heat-taking oil 88L steam, and the circulating heat-taking oil 88L steam or secondary steam formed by contact with internal reflux liquid contacts with a stream based on first diesel oil for evaporation of diesel components in the stream based on the first diesel oil;

the recycled heat removal oil 88L is selected from one or more of the following materials:

(1) Discharging the circulating heat-taking oil 88L in a tower section above a first diesel oil liquid discharge outlet of a fractionating tower used in the slurry decompression separation process C3121, wherein the circulating heat-taking oil 88L contains naphtha components, and the average boiling point temperature of the circulating heat-taking oil 88L is lower than that of the first diesel oil liquid;

(2) the first diesel oil liquid outlet of the fractionating tower used in the slurry decompression separation process C3121 is at the same height position, and the circulating heat taking oil 88L is discharged, and the boiling range of the circulating heat taking oil 88L is the same as that of the first diesel oil liquid;

(3) the slurry pressure reduction separation process C3121 uses a fractionation column having a first diesel liquid discharge port from which the circulating heat-removing oil 88L is discharged, the circulating heat-removing oil 88L containing wax oil components, and the circulating heat-removing oil 88L having an average boiling temperature higher than that of the first diesel liquid.

In the present invention, generally, the heat exchange and temperature rise of the heat stream existing in the separation process of the circulating heat-taking oil 99L or the circulating heat-taking oil 88L and the heat high-pressure oil S110L are performed, wherein the heat stream existing in the separation process of the heat high-pressure oil S110L is selected from one or more of the following:

(1) a hot material flow formed after the hot high-pressure oil separation and depressurization;

(2) a hot stream present in a hot low-split gas separation column system;

(3) The hot stream present in slurry pressure reduction separation process C3121;

(4) and (3) reducing the pressure of the high-temperature high-pressure oil to form a hot material flow.

In the invention, the thermal high-pressure oil S110L is divided into a first branch thermal high-pressure oil S110L-1 and a second branch thermal high-pressure oil S110L-2;

the second branch heat high-pressure oil S110L-2 is used for separating residual oil obtained after hydrocarbon components with the conventional boiling point lower than 540 ℃ are separated, and part or all of the residual oil is used as circulating oil R-SHC-VR to be used for carrying out a heavy oil removal suspension bed hydrocracking reaction in the R10 circulating reaction process;

the hydrocarbon component with the conventional boiling point lower than 540 ℃ separated from the first branch thermal high-fraction oil S110L-1 is separated from the hydrocarbon component with the conventional boiling point lower than 540 ℃ separated from the second branch thermal high-fraction oil S110L-2 in a combined way.

In the present invention, in general, during the heat exchange and temperature increase process of the cold high-pressure oil S130L or the pressure-reducing flash oil thereof, the cold high-pressure oil S130L or the pressure-reducing flash oil thereof exchanges heat with the hot oil product and/or the middle-stage return oil discharged from the slurry pressure-reducing separation process C3121 and/or with the bottom oil discharged from the slurry pressure-reducing separation process C3121.

In the invention, the asphaltene-containing material obtained after the depressurization of the hot high-pressure oil S110L is directly mixed with the petroleum-based oil containing wax oil component and residual oil component to realize rapid cooling stabilization.

In the invention, generally, the heat of the separation process of recovering heavy oil suspension bed hydrocracking generated oil in the heat exchange and temperature rising process of petroleum base oil products becomes thermal state petroleum base oil products, wherein the thermal state petroleum base oil products comprise a base oil heat exchange process discharged from a slurry decompression separation process C3121;

separating at least one part of diesel oil components from petroleum base oil products through an atmospheric fractionation process, and obtaining the base oil of the petroleum base oil products in the atmospheric fractionation process after the components with lower boiling points are separated;

and directly mixing the base oil of the petroleum base oil in the normal pressure fractionation process with the asphaltene-containing material obtained after the depressurization of the thermal macromolecule oil S110L to realize the rapid cooling stabilization of the asphaltene-containing material obtained after the depressurization of the thermal macromolecule oil S110L.

In the invention, at least a part of hydrogen-rich gas based on cold high-pressure gas S130V is returned to the heavy oil suspension bed hydrocracking reaction process R10 as circulating hydrogen RH for recycling, and the mode of obtaining the circulating hydrogen RH is selected from one or more of the following modes:

(1) part of the cold high-pressure gas S130V is used as circulating hydrogen RH;

(2) at least a part of the cold high-pressure gas S130V is converted into hydrogen sulfide cold high-pressure gas through a hydrogen sulfide removal process, and at least a part of the hydrogen sulfide cold high-pressure gas is used as circulating hydrogen RH;

(3) At least a part of the cold high-pressure gas S130V is converted into hydrogen sulfide cold high-pressure gas through a hydrogen sulfide removal process, at least a part of the hydrogen sulfide cold high-pressure gas is separated into permeated hydrogen and non-permeated tail gas through a permeation membrane separation process, and at least a part of the permeated hydrogen is used as circulating hydrogen RH;

(4) at least a part of cold high-pressure gas S130V is converted into hydrogen sulfide cold high-pressure gas through a hydrogen sulfide removal process, at least a part of the hydrogen sulfide cold high-pressure gas is separated into primary permeation hydrogen, secondary permeation hydrogen and non-permeation tail gas through a permeation membrane separation process of two stages of serial operation, and at least a part of the primary permeation hydrogen is used as circulating hydrogen RH;

(5) at least a part of cold high-pressure gas S130V is converted into hydrogen sulfide cold high-pressure gas through a hydrogen sulfide removal process, at least a part of the hydrogen sulfide cold high-pressure gas is separated into primary permeation hydrogen, secondary permeation hydrogen and non-permeation tail gas through a permeation membrane separation process of two stages of serial operation, and at least a part of the primary permeation hydrogen is used as circulating hydrogen RH; at least a part of the secondary permeated hydrogen is separated into pressure swing adsorption purified hydrogen and pressure swing adsorption tail gas through the pressure swing adsorption hydrogen purification process, and at least a part of the pressure swing adsorption purified hydrogen is used as circulating hydrogen RH.

In general, according to the present invention, the first diesel liquid or the first diesel light component removal process base oil obtained in the separation system KC3301 has a content of 85 to 100% by weight of hydrocarbon components having a conventional boiling point of 180 to 350 ℃.

In the present invention, in general, after the slurry vacuum separation process C3121, at least a part of the stream based on the vacuum separation process bottom oil is cooled down, it is returned to the buffer space of the vacuum separation process bottom oil of the slurry vacuum separation process C3121 as circulating quench oil to reduce the temperature of the liquid phase of the buffer space of the vacuum separation process bottom oil.

In the present invention, in general, in the slurry pressure reduction separation process C3121, the stream based on the hot low-split oil enters the separation process with an operating pressure of negative pressure, with or without increasing the enthalpy through the heating furnace.

In the present invention, the first diesel light component removing fractionation tower used in the first diesel light component removing process of the separation system KC3301 is generally characterized in that stripping steam enters the bottom of a mass transfer element in the tower, or a bottom reboiler is arranged, so as to achieve the purpose of removing light hydrocarbon components of the first diesel.

In the invention, a light oil separation product of the pre-flash tower C3101 is obtained in a pre-flash tower C3101 system;

removing at least a portion of the hydrocarbon components having a conventional boiling point below 120 ℃ from the stream based on the pre-flash column C3101 light oil separation product to obtain a second diesel rich oil comprising a naphtha component, a diesel component;

The second diesel-rich separation process is characterized by: at least a portion of the second diesel-rich naphtha component, diesel component-containing stream, after having been subjected to an endothermic or non-endothermic process, to a slurry pressure reduction flash vapor separation process of slurry pressure reduction separation process C3121, contacting with the slurry pressure reduction flash vapor-based vapor phase stream and vaporizing the naphtha component in the second diesel-rich stream, to the slurry pressure reduction flash vapor-based vapor phase stream, and then condensing the naphtha component vapor from the second diesel-rich stream to a ninth naphtha-rich liquid; and (3) introducing the diesel components in the stream containing naphtha components and diesel components based on the second diesel-rich stream into the diesel liquid separated by condensation of the slurry-based reduced-pressure flash vapor.

removing at least a part of hydrocarbon components with conventional boiling points lower than 120 ℃ from a stream based on a pre-flash tower C3101 light oil separation product to obtain second diesel-rich oil mainly composed of naphtha components and diesel components;

removing at least a portion of the hydrocarbon components having conventional boiling points below 120 ℃ from the stream based on the pre-flash column C3101 light oil separation product to obtain a second diesel rich in naphtha components consisting essentially of diesel components;

the second diesel-rich separation process is characterized by: at least a portion of the second diesel-rich naphtha component, diesel component-based stream, after having been subjected to an endothermic or non-endothermic process, to a slurry pressure reduction flash separation process of slurry pressure reduction separation process C3121, contacting with a slurry pressure reduction flash steam-based naphtha component-containing vapor phase and vaporizing the naphtha component in the second diesel-rich stream, to a slurry pressure reduction flash steam-based vapor phase stream, and then condensing the naphtha component steam from the second diesel-rich stream to a ninth naphtha-rich liquid; the diesel components in the stream containing naphtha components and diesel components based on the second diesel rich stream enter the diesel liquid separated by condensation of the slurry-based reduced pressure flash vapor;

the material flow containing naphtha component and diesel component based on the second diesel oil enters a fractionating tower of the slurry decompression separation process C3121, and contacts with gas phase discharged from a mass transfer section in the tower for generating the first diesel oil liquid to conduct heat and mass transfer.

Detailed Description

The present invention is described in detail below.

The pressure in the present invention refers to absolute pressure.

The conventional boiling point refers to the vapor-liquid equilibrium temperature of a substance at one atmosphere.

The conventional boiling range as used herein refers to the conventional boiling range of the distillate fraction.

The specific gravity according to the present invention means, unless otherwise specified, the ratio of the density of the liquid at normal pressure and 15.6 ℃ to the density of the water at normal pressure and 15.6 ℃.

The composition or concentration or content or yield values of the components described in the present invention are weight reference values unless otherwise specified.

The conventional gas hydrocarbon refers to hydrocarbon which is in a gaseous state under the conventional condition, and comprises methane, ethane, propane and butane.

The conventional liquid hydrocarbon used in the present invention refers to hydrocarbons which are liquid under conventional conditions, and includes pentane and hydrocarbons with higher boiling points.

The impurity elements described in the present invention refer to non-hydrogen, non-carbon, non-metal components such as oxygen, sulfur, nitrogen, chlorine, etc. in the raw oil.

The impurity component refers to hydroconversion of non-hydrocarbon components in the raw oil, such as water, ammonia, hydrogen sulfide, hydrogen chloride, and the like.

The naphtha component of the present invention refers to conventional liquid hydrocarbons having conventional boiling points below 180 ℃.

The diesel component refers to hydrocarbons with conventional boiling points of 180-350 ℃.

The wax oil component refers to hydrocarbons with conventional boiling points of 350-530 ℃.

The residuum component of the present invention refers to hydrocarbons having a conventional boiling point greater than 530 ℃.

The light hydrocarbon refers to naphtha components and hydrocarbons with lower boiling points.

The hydrogen-oil volume ratio refers to the ratio of the standard state volume flow of hydrogen to the normal pressure and 20 ℃ volume flow of a specified oil flow.

The weight chemical hydrogen consumption of the heavy oil R10F hydrogenation reaction process refers to the weight of hydrogen consumed in the hydrogenation reaction process for chemical reaction of the heavy oil R10F per unit weight, such as 2.00%.

In the heavy oil suspension bed hydrogenation reaction process, the gas-liquid contact mode in the suspension bed hydrogenation reactor is not limited, and the heavy oil suspension bed hydrogenation reaction process can be any effective mode.

In the heavy oil suspension bed hydrogenation reaction process, the granular heavy oil suspension bed hydrogenation catalyst used in the reaction process is suspended in a liquid phase in the reaction process to form slurry oil with dispersed catalyst particles, so the heavy oil suspension bed hydrogenation reaction process can also be called as a heavy oil slurry bed hydrogenation reaction process.

In the heavy oil suspension bed hydrogenation reaction process, a suspension bed hydrogenation reactor of the heavy oil suspension bed hydrogenation reaction process generally belongs to an up-flow hydrogenation reactor, and the dominant direction of macroscopic flow of a process medium in a reaction space or a hydrogenation catalyst bed layer is from bottom to top.

The invention discloses an up-flow type suspended bed reactor, which belongs to an up-flow type expanded bed reactor.

The upflow expanded bed reactor is a vertical upflow reactor, and belongs to an expanded bed catalytic reactor when a catalyst is used; vertical means that the central axis of the reactor is vertical to the ground in the working state after installation; the upflow type refers to the reaction process that the material main body flow direction passes through the reaction space or the catalyst bed layer from bottom to top or flows in the same direction with the upward catalyst; the expanded bed refers to an operating catalyst bed in an expanded state, the catalyst bed expansion ratio is defined as the ratio KBED of the maximum height CWH of the catalyst bed in an operating state when the reaction material passes through to the height CUH of the empty bed of the catalyst bed in a resting state, generally, KBED is referred to as a micro expanded bed when KBED is lower than 1.10, ebed is referred to as an ebullated bed when KBED is between 1.25 and 1.55, and a suspended bed is considered to be the most extreme form of expanded bed.

The back-mixed flow expanded bed reaction zone refers to the operation mode of the reaction zone using an expanded bed reactor, wherein liquid flow back mixing exists or circulating liquid exists; by a back mixed stream or recycle stream is meant at least a portion of the liquid phase XK-L in intermediate XK or end product XK at point K of the process as recycle stream XK-LR returned to the reaction zone upstream of XK, the reaction product of recycle stream XKLR flowing through point K and being present in XK. The manner of forming the back mixed flow may be any suitable manner, such as providing an internal circulation tube, an internal external circulation tube, an internal liquid collecting cup, a flow guiding tube, a circulating pump, an external circulating tube, etc.

The liquid collecting cup or the liquid collector arranged in the reactor refers to a container which is arranged in the reactor and is used for collecting liquid, the upper part or the side surface of the upper part is usually opened, and a flow guide pipe is arranged at the bottom or the side surface of the lower part and is used for discharging the collected liquid; the top liquid trap of the expanded bed reactor, typically installed in the liquid removal zone of the gas-liquid feed, yields a liquid and gas-liquid mixed phase stream or yields liquid and gas.

The suspension bed reactor of the present invention may be in any suitable form, and may be an empty tube suspension bed reactor to form a plug flow or a back-mixed flow with internal circulation, may be a back-mixed flow using an internal circulation draft tube to form an internal circulation or an internal external circulation, may be a back-mixed flow using an external circulation tube thereof to flow an upper reaction space liquid into an external circulation flow of a lower reaction space former, or may be a back-mixed flow using a top product liquid collecting and draft system to form a forced internal circulation flow through a circulation pressurizing system.

The invention relates to a thermal high separator, which is gas-liquid separation equipment for separating hydrogenation reaction intermediate products or final products.

The suspension bed hydrogenation reactor disclosed by the invention can be operated in the following modes:

(1) a suspended bed hydrogenation reactor;

(2) the fluidized bed catalyst whose activity has been reduced can be discharged from the bottom of the bed in an intermittent manner, and fresh fluidized bed catalyst can be fed from the upper portion of the bed in an intermittent manner to maintain the bed fluidized bed catalyst inventory.

The heavy oil suspension bed hydrocracking reaction process of the invention is characterized in that raw material heavy oil R10F generally refers to an asphaltene-containing hydrocarbon oil mainly (with the weight concentration of more than 50%) composed of hydrocarbon components with the conventional boiling point higher than 530 ℃, such as vacuum residue, atmospheric residue and mixed oil of a plurality of hydrocarbon materials; when the heavy oil R10F is mixed from several different properties of the split feed oils, at least one of the split feed oils contains asphaltenes and one or more of the other split feed oils contains asphaltenes or does not contain asphaltenes.

The heavy oil suspension bed hydrocracking reaction process R10 generally refers to a suspension bed hydrocracking reaction process of vacuum residuum, and aims to realize high cracking conversion rate (the cracking conversion rate is generally expected to be more than 90 weight percent or 95 weight percent) of hydrocarbon components with normal boiling point higher than 530 ℃ in heavy oil R10F as much as possible, namely, reduce the ratio of the hydrocarbon components with normal boiling point higher than 530 ℃ in discharged unconverted oil as much as possible, and simultaneously improve the heat energy recycling efficiency and reduce the catalyst consumption as much as possible; of course, the heavy oil suspension hydrocracking reaction process of the present invention also includes other heavy oil suspension hydroconversion reaction processes that produce a readily pyrocondensation hydrocarbon component at high temperatures in addition to the vacuum residuum suspension hydrocracking reaction process.

In general, in order to ensure the relative economic competitiveness of different types of heavy oil hydrogenation processes, the properties of the feedstock vacuum residuum (containing 85 to 90% of vacuum residuum component, carbon residue content is typically 18 to 23% by weight) of the ebullated bed hydrocracking process are more severe than those of the feedstock oil of the fixed bed hydrodesulfurization process VRDS (containing 55 to 65% of vacuum residuum component, carbon residue content is typically 9 to 14% by weight), while the properties of the feedstock vacuum residuum (containing 90 to 95% of vacuum residuum component, carbon residue content is typically 22 to 33% by weight) of the suspended bed hydrocracking process are more severe than those of the feedstock vacuum residuum of the ebullated bed hydrocracking process.

The feedstock vacuum resid for suspension bed hydrocracking reactions typically has an asphaltene content of greater than 12%, typically greater than 18%, particularly greater than 22%, its Conn carbon residue value typically greater than 16%, typically greater than 27%, particularly greater than 33%, its organic sulfur content typically greater than 0.5%, typically greater than 2.0%, particularly greater than 5.0%, its organic nitrogen content typically greater than 0.15%, typically greater than 0.30%, particularly greater than 0.50%, and its organometallic content typically greater than 0.015%, typically greater than 0.025%, particularly greater than 0.100%.

The heavy oil suspension bed hydrocracking generated oil refers to a hydrocarbon oil stream mainly composed of conventional liquid hydrocarbon based on heavy oil suspension bed hydrocracking reaction products; the heavy oil suspension bed hydrocracking product oil can be 1 path, 2 paths or multiple paths of hydrocarbon streams, and at least 1 path of hydrocarbon stream in the heavy oil suspension bed hydrocracking product oil generally contains asphaltene components, and the streams are separated into gas, hydrocarbon distillate oil with different boiling ranges and base oil formed by non-evaporating components after flash evaporation and fractionation steps.

The bottom oil refers to hydrocarbon liquid composed of non-evaporating hydrocarbon oil components after flash evaporation and fractionation steps.

The invention relates to a cooling stabilization of heavy oil suspension bed hydrocracking generated oil, which refers to a large-span cooling process of heavy oil suspension bed hydrocracking generated oil in a separation fractionation process, wherein the cooling process is mainly not temperature reduction caused by depressurization evaporation, but is mainly limited cooling adopted for realizing thermal stabilization of asphaltene components in a liquid phase, and the reasons are that: asphaltenes in heavy oil suspension bed hydrocracking process oils undergo thermal condensation reactions at high temperatures (e.g., > 380 ℃) to form thermal condensates, once the thermal condensates are concentrated beyond the upper solubility limit, the free bulk solution accumulates into a second liquid phase, the asphaltene phase, and thermal condensates such as soft coke or coke are formed, and accumulation of deposits can lead to forced shut-down of the fractionation system; whereas for heavy oil suspension bed hydrocracking processes of the cyclic conversion type, particularly of the large cycle ratio cyclic conversion type, the formation of oil separation fractionation processes constantly produces heat condensate, which will lead to an increase in the cyclic accumulation of asphaltenes in the solution of the reactor, which in essence will limit the single pass conversion, the overall conversion of fresh heavy oil during the suspension bed hydrocracking reaction in order to maintain the stability of the asphaltene solution of the fresh heavy oil reaction process (i.e. limit the asphaltene concentration value below the safe concentration value). In fact, the stability of the asphaltene solution is the first condition to be ensured for maintaining long-term stable operation, whether the heavy oil is in the process of a suspension bed hydrocracking reaction or in the process of separating and fractionating the oil produced by the suspension bed hydrocracking of the heavy oil.

In heavy oil suspension hydrocracking reactions, because non-asphaltene components in the feedstock vacuum residuum are more prone to hydrocracking than asphaltene components, vacuum residuum suspension hydrocracking reactions necessarily result in concentration of asphaltenes in unconverted oil, meaning that the properties of the same boiling range vacuum tower bottoms are much worse than those of the same boiling range feedstock vacuum residuum, with unconverted oil large circulation being much worse than the initial reaction process solution properties (asphaltene concentration is relatively high) in the operating mode than the reaction process solution properties (asphaltene concentration is relatively low) in the single pass through the operating mode of a single fresh vacuum residuum; on the other hand, the end reaction process solution properties (high concentration of aromatic components in solution, better dissolution capacity for asphaltenes) of the mode of operation with a large recycle ratio of unconverted oil and low per pass conversion of the reduced slag component are better than the end reaction process solution properties (low concentration of aromatic components in solution, poor dissolution capacity for asphaltenes) of the single pass of fresh vacuum residuum and high conversion mode of operation.

A large amount of experimental data and production operation data show that even in a suspension bed hydrocracking process of vacuum residuum using a nano molybdenum-based catalyst excellent in hydrogenation performance, such as EST vacuum residuum suspension bed hydrocracking process of Italian Eniensis company, under the conditions of 16-17 MPa of reaction operation pressure, 420-440 ℃ of operation temperature, 100-150% of cycle tail oil weight ratio and 88-95% of total conversion rate of fresh vacuum residuum, the asphaltene concentration in tail oil is 120-160% or more of that of fresh vacuum residuum, the carbon residue value of tail oil is 160-200% or more of that of fresh vacuum residuum, the ratio of the carbon residue value of tail oil to the carbon residue value of fresh vacuum residuum is higher than that of tail oil asphaltene concentration to that of fresh vacuum residuum, which is the contribution of macromolecular olefins, and the thermal stability of macromolecular olefins are poor, i.e., thermal condensation reaction occurs at high temperature (for example, 380 ℃ or more) to generate thermal condensate.

In general, the heavy oil suspension bed hydrocracking process of the present invention uses MOS ₂ The morphological heavy oil suspension bed hydrocracking molybdenum catalyst particles, due to the characteristics of thermal cracking and the lower hydrogenation saturation speed relative to the thermal cracking speed, inevitably lead to the existence of a large amount of unsaturated olefin, and also inevitably lead to the thermal condensation of part of asphaltene to form macromolecular thermal condensates which have lower hydrogen content and are more difficult to hydrogenate and thermally crack, and the macromolecular thermal condensates can undergo thermal condensation reaction under the condition of losing hydrogen environment at high temperature, which is the theoretical basis of the need of cooling and stability for the hydrocracking of the heavy oil suspension bed to generate oil, and the experimental verification has been carried out.

In the EST residual oil suspension bed hydrocracking process of Italian Erniy company, because tail oil contains a large amount of macromolecular olefin, inferior asphaltene and other components with poor thermal stability, heat condensate can be generated in a high temperature state, meanwhile, after the partial pressure protection of hydrogen is lost, metal sulfide (impurity metalate and catalyst molybdenum sulfide) has a certain thermal cracking catalytic effect to promote the generation of the heat condensate, and the generation of the heat condensate is also aggravated, so that the separation and fractionation process of the depressurized thermal high-molecular oil is not only a physical process, but also a chemical process with a certain amount of thermal condensation reaction at a high temperature, and in the operation method with a large amount of circulating tail oil, the heat condensate gradually accumulates in the fractionation process and the reaction process, a part of the heat condensate is accumulated in the reaction and fractionation system along with the discharge of the external tail oil, so that the liquid phase property of the reaction system and the fractionation system can be gradually deteriorated, and finally, in order to control the liquid phase property of the reaction system and the fractionation system (limiting the concentration of asphaltene to be lower than a single pass safety value), the conversion and the total conversion rate of fresh residual oil reaction raw materials are reduced.

As described above, the overall conversion of vacuum resid in a vacuum resid suspension hydrocracking unit is affected not only by the intrinsic conversion of the reaction process but also by the thermal stability of the separated bottoms (asphaltene concentrate phase) of the suspension hydrocracking unit (particularly, the vacuum distillation process), which is associated with the separation, fractionation process heat condensate yield, and by the concentration of cycle tail asphaltenes (heavy wax oil withdrawal) of the suspension hydrocracking unit (associated with the concentration of asphaltenes in the cycle oil, the concentration of asphaltene solvent, and the yield of off-stream tail), and the above 2 factors are coupled to each other in a conventional single fractionation process.

When the stability of the asphaltene solution in the oil separation process generated by the hydrocracking of the suspension bed is threatened (which is manifested by coking of a hot low-pressure separator, coking of the bottom of an atmospheric tower and coking of the bottom of a vacuum tower), in order to maintain continuous operation, the conversion rate of the reaction process can only be forced to be reduced, so that the proportion of unconverted oil discharged outwards (namely, the yield of the vacuum distillation bottom oil is increased, the concentration of the catalyst in the vacuum distillation bottom oil is reduced), the proportion of catalyst carried by circulating oil is reduced, the consumption of fresh catalyst or precursors thereof is increased, or the circulating oil quantity is forced to be increased, and the processing load is reduced.

Conversely, from the viewpoint of optimizing the process operation, if the stability of the asphaltene solution in the separation process of the oil produced by hydrocracking the suspension bed can be improved, the reduction of the heat condensate yield is advantageous for prolonging the continuous operation period, increasing the conversion rate in the reaction process, reducing the proportion of unconverted oil discharged outside (i.e., reducing the yield of the vacuum distillation base oil and increasing the concentration of the catalyst therein), and consequently increasing the proportion of catalyst carried by the circulating oil, the consumption of fresh catalyst or its precursor can be reduced, and the amount of circulating oil can be reduced and the processing amount of the apparatus can be increased.

The above analysis is based on experimental studies and production experience, and therefore, in order to increase the thermal stability of the heavy oil suspension bed hydrocracking produced oil, the operating temperature of the asphaltene-containing thermosensitive liquid phase during its separation and fractionation must be reduced.

After the temperature reduction is carried out to improve the thermal stability of the oil produced by hydrocracking the heavy oil suspension bed, the removal or transfer of the heat energy carried by the oil produced by hydroconversion of the heavy oil suspension bed is necessarily caused, and the utilization mode of the heat energy is necessarily influenced by the 'stable operation mode of the temperature reduction of the oil produced by hydrocracking the heavy oil suspension bed'.

In the fractionation process, the circulating oil in the thermal high-pressure oil has triple functions, on one hand, the circulating oil is a huge amount of heat carrier, and after the reaction belt is discharged out of the reactor, the heat is released in the stabilization and temperature reduction processes in the separation and fractionation processes, and on the other hand, the heat is released in the depressurization flash evaporation process in the fractionation process; the heavy oil suspension bed hydrogenation conversion reaction process in the reactor is used as an asphaltene stability solvent, namely the single-pass conversion rate is reduced, the asphaltene concentration in the liquid phase at the outlet of the reactor is reduced, and the concentration of colloid and heavy aromatic hydrocarbon in the liquid phase at the outlet of the reactor is increased;

In fact, since the circulating oil is essentially non-evaporated during the reaction and fractionation process, the outlet operating temperature of the heavy oil suspension bed hydroconversion reactor is very high (such as 420-440 ℃) and the temperature of the flash zone of the vacuum column is relatively low (such as 340-360 ℃) and is about 60-90 ℃, the circulating oil plays a role of a liquid heat carrier with a large amount of reaction heat, and generally, the weight flow rate of the circulating oil is slightly larger than the weight flow rate of the raw oil (or the weight flow rate of the net generated oil), so that the circulating oil carries a huge amount of reaction heat, which is a huge heat reservoir, and plays the following three roles essentially in the fractionation part:

firstly, converting the clean reaction generated oil in the thermal high-pressure oil into a large amount of heat energy which is removed in the stabilizing and cooling process, and carrying out heat release feedback in the evaporation and heat absorption step in the separation and fractionation process, thereby improving the equilibrium flash evaporation temperature in the separation and fractionation process and being beneficial to improving the extraction rate;

secondly, the method is used for balancing a large amount of heat absorption of the generated oil of the net reaction in the hot high-pressure oil in the fractional distillation evaporation process, so that the balance temperature of the flash evaporation step can be reduced under the same flash evaporation steam extraction rate condition, and the improvement of the thermal stability of the bottom oil is facilitated;

third, there is a large amount of heat energy that needs to be recovered, and the temperature level of the heat energy is between the high-temperature oil separating temperature (such as 420-440 ℃) and the stabilizing temperature (such as 380-390 ℃), in other words, how to reasonably recover the heat energy at the high temperature.

CN115975675a discloses a heavy oil suspension bed hydroconversion method, which is characterized in that the reaction generated oil KP is injected with quenching oil, mixed and cooled stably, and the method is suitable for the vacuum residuum suspension bed hydrocracking process with large circulation ratio circulating oil, the quenching oil is selected from hydrocarbon oil containing heavy oil components and low boiling point components of reaction raw materials, the bottom oil separated from the heavy oil and KP of the reaction raw materials, and compared with the cooling mode of indirect heat exchange and heat transfer of KP, the method has the advantages that: (1) KP realizes rapid cooling; (2) the quenching oil releases heat in the KP subsequent evaporation process, so that the extraction rate can be improved, the flow rate is flexible to adjust, and the temperature level of the finally recovered heat energy is high; (3) the external quenching oil can reduce the concentration of asphaltene in the bottom oil; (4) the circulating quenching oil transfers heat at a stable temperature and can flexibly supply heat to multiple points; (5) the generated oil is branched and operated by different quenching oil cooling distillation combinations, so that the yield of discharged tail oil can be reduced, the heat recovery efficiency can be improved, the reaction conversion rate can be improved, and the processes of crude oil combined distillation, inverted preheating of reaction raw materials, heating of an oil-free heating furnace in normal operation and the like are formed. CN115975675a describes a heavy oil suspension bed hydroconversion method document, which relates to heavy oil suspension bed hydroconversion reaction process, heavy oil suspension bed hydroconversion reaction conditions (reaction temperature, reaction pressure, circulating oil circulation ratio, heavy oil suspension bed hydroconversion catalyst and its dosage), heavy oil conversion rate and separation and fractionation methods of heavy oil suspension bed hydroconversion reaction generated oil.

The invention essentially constructs a distillation combination process of mixed oil containing diesel oil and component wax oil components, reasonably utilizes heat energy (especially condensation latent heat) contained in vapor phase flow to be condensed containing the diesel oil components and/or wax oil components in the vacuum fractionation process of thermal high-molecular oil in heavy oil suspension bed hydrocracking generated oil, vaporizes the diesel oil components in bottom oil of the naphtha-removed component of the cold high-molecular oil introduced into the heavy oil suspension bed, and condenses the vaporized diesel oil components into diesel oil. Because the heat supply of one huge heat is reduced, the heat extraction of one huge heat is also reduced, the remarkable effects of simplifying the system and reducing the energy consumption are realized, and the heavy oil suspension bed hydrocracking device for large-scale raw material processing amount has huge economic benefit and general application value.

The low-level middle-temperature heat refers to middle-temperature heat with lower temperature, and the high-level middle-temperature heat refers to middle-temperature heat with higher temperature, which are in a relative relation.

Separating naphtha components from diesel components from a pre-flash tower C3101 light oil separation product by adopting a principle similar to the method for separating diesel oil by cold high separation of heavy oil suspension bed hydrocracking products, firstly, removing at least one part of hydrocarbon components with the conventional boiling point lower than 120 ℃ from a material flow based on the pre-flash tower C3101 light oil separation product to obtain second diesel-rich oil containing the naphtha components and the diesel components; then, in general, the second diesel rich separation process is characterized by: at least a portion of the second diesel-rich naphtha component, diesel component-based stream enters the slurry pressure-reducing flash separation process of slurry pressure-reducing flash separation process C3121, contacts the slurry pressure-reducing flash steam-based naphtha component-containing vapor phase and vaporizes the naphtha component in the second diesel-rich stream, enters the slurry pressure-reducing flash steam-based vapor phase stream, and then the naphtha component steam from the second diesel-rich stream is condensed into a ninth naphtha-rich liquid; typically, a stream containing naphtha component, diesel component based on the second diesel-rich stream enters the fractionation column of slurry pressure reduction separation process C3121 for heat and mass transfer in contact with the vapor phase exiting the mass transfer section of the column producing the first diesel liquid, acting as the cold reflux for the fractionation section.

The characteristic parts of the present invention are described below.

(2) removing more than 50% by weight of the naphtha component;

(3) more than 95% by weight of the naphtha component is removed.

(1) asphaltene weight concentration greater than 12%;

(2) the Kangshi carbon residue value is higher than 16%;

(3) the weight content of organic sulfur is higher than 0.5%;

(4) the organic nitrogen weight content is higher than 0.15%;

(5) the weight content of the organic metal is higher than 0.015%;

The circulation ratio K100 is 0.40-2.5;

①≤0.80；

②0.80～1.20；

③1.20～1.60；

④1.60～2.50；

⑤≥2.50。

(2) A hot stream present in a hot low-split gas separation column system;

The general principles of controlling the concentration of gaseous hydrogen sulfide in the hydrogenation process of the present invention are described below.

For heavy oil suspension bed hydrocracking processes with high nitrogen content and low sulfur content, any supplemental sulfur may be added to any hydrogenation process as needed to maintain the lowest partial pressure of hydrogen sulfide in the initial reaction process, but is typically added to the inlet of the most upstream hydrogenation process to ensure that the minimum concentration of hydrogen sulfide necessary for the reaction process, such as 500ppm (v) or 1000ppm (v) or 3000ppm (v), is desired to ensure that the partial pressure of hydrogen sulfide necessary for the catalyst is not below the minimum specified value to ensure that the catalyst has a sulfided form. The supplemental sulfur can be hydrogen sulfide or materials which can be converted into hydrogen sulfide and have no adverse effect on the hydroconversion process, such as hydrogen sulfide-containing gas or oil products, or liquid sulfur or carbon disulfide or dimethyl disulfide which generate hydrogen sulfide after contacting with high-temperature hydrogen, and the like.

The general principles of the high pressure separation process of the hydrogenation reaction effluent of the present invention are described in detail below.

The high pressure separation process of the hydrogenation effluent usually comprises a cold high pressure separator, and when the hydrocarbon oil in the hydrogenation effluent is high in density (such as close to water density) or high in viscosity or difficult to separate with water emulsification or contains solid particles, a hot high pressure separator with an operation temperature of usually 150-450 ℃ is also required, and the hydrogenation effluent enters the hot high pressure separator to be separated into a hot high-pressure gas mainly composed of hydrogen and a hot high-pressure oil liquid mainly composed of conventional liquid hydrocarbon and possibly solids in volume, and the hot high-pressure gas enters the cold high-pressure separator with an operation temperature of usually 20-80 ℃ to be separated into cold high-pressure oil and cold high-pressure gas, and the following objects are achieved because a large amount of high-boiling components enter the hot high-pressure oil liquid: the cold high-oil separation density is reduced or the viscosity is reduced or the cold high-oil separation is easy to separate from water. The high-pressure separation process of the hydrogenation reaction effluent is provided with a hot high-pressure separator, and the hydrogenation reaction effluent also has the advantage of reducing heat loss, because the hot high-pressure oil separating liquid can avoid the cooling process of using an air cooler or a water cooler for hot high-pressure gas. Meanwhile, part of the hot high-pressure oil liquid can be returned to the upstream hydrogenation reaction process for recycling, so that the overall raw material property of the hydrogenation reaction process receiving the circulating oil is improved, or the circulating hot high-pressure oil is subjected to circulating hydrogenation.

Between the hot high pressure separation part and the cold high pressure separation part, a warm high pressure separation part can be arranged as required, at this time, the hot high pressure separation gas is cooled to become a gas-liquid two-phase material, and the gas-liquid two-phase material is separated into a warm high pressure separation gas mainly composed of hydrogen in volume and a warm high pressure separation oil liquid mainly composed of conventional liquid hydrocarbon and possibly solid in volume in the high pressure separator, and the warm high pressure separation gas enters the cold high pressure separation part for cooling and gas-liquid separation.

The temperature of the hydrogenation effluent or hot high-pressure gas or warm high-pressure gas is typically reduced (typically by heat exchange with the feed to the reaction section) to about 220 to about 100 c (which is a temperature above the crystallization temperature of the ammonia hydrosulfide and the crystallization temperature of the ammonia chloride in the vapor phase of the hydrogenation effluent) before it is introduced into the cold high-pressure separation section, and then washing water is typically injected into the reaction effluent to form a post-injection hydrogenation effluent, which may require 2 or more injection points, and the washing water is used to absorb ammonia and other impurities that may be produced, such as hydrogen chloride, etc., while the aqueous solution after absorption of ammonia necessarily absorbs hydrogen sulfide. In the cold high-pressure separation part, the hydrogenation reaction effluent after water injection is separated into: a cold high-pressure gas mainly composed of hydrogen in volume, a cold high-pressure oil mainly composed of conventional liquid hydrocarbon and dissolved hydrogen, and a cold high-pressure water mainly composed of water and dissolved with ammonia and hydrogen sulfide. The cold high water content is generally 0.5 to 15% (w), preferably 1 to 8% (w) of ammonia. One purpose of the wash water injection is to absorb ammonia and hydrogen sulfide in the hydrogenation reaction effluent and prevent the formation of ammonia hydrosulfide or polysulfide ammonia crystals from blocking the heat exchanger channels, increasing the system pressure drop. The injection amount of the washing water should be determined according to the following principle: on the one hand, the wash water is separated into vapor phase water and liquid phase water after being injected into the hydrogenation reaction effluent, and the amount of the liquid phase water must be greater than zero, preferably 30% or more of the total amount of the wash water; in yet another aspect, the wash water is used to absorb ammonia from the hydrogenation reaction effluent, preventing the ammonia concentration of the higher gases from being too high, reducing catalyst activity, and generally the lower the ammonia volume concentration of the higher gases, the better, typically no greater than 200ppm (v), and most preferably no greater than 50ppm (v). The operating pressure of the cold high-pressure separator is the pressure of the hydrogenation reaction part minus the actual pressure drop, and the difference between the operating pressure of the cold high-pressure separator and the hydrogenation reaction pressure is not too low or too high, and is generally 0.35-3.2 MPa, and is generally 0.5-1.5 MPa. The hydrogen volume concentration of the cold high-pressure gas should not be too low (resulting in an increase in the operating pressure of the apparatus), and should generally be not less than 70% (v), preferably not less than 80% (v), and most preferably not less than 85% (v). At least a portion, typically 85 to 100 percent, of the cold high-pressure gas is returned to the hydrogenation portion for recycle as previously described to provide the necessary amount and concentration of hydrogen in the hydrogenation portion; in order to increase the investment efficiency of the plant, it is necessary to ensure that the concentration of the recycle hydrogen is not lower than the aforesaid low limit, for which purpose a portion of the cold high-pressure gas can be removed to exclude methane, ethane produced by the reaction, depending on the specific feedstock properties, reaction conditions, product distribution. For the discharged cold high-pressure gas, the separation of hydrogen and non-hydrogen gas components can be achieved using a conventional membrane separation process or pressure swing adsorption process or oil washing process, and the recovered hydrogen is used as new hydrogen.

For the heavy oil suspension bed hydrocracking process, because the CH4, C2H6 and H2S yields are huge, part or all of cold high-purity gases such as about 30-100% of cold high-purity gases are usually recycled after the permeate hydrogen obtained after purification by a membrane separation process is pressurized and returned to the hydrogenation reaction process, and the non-permeate gas can be recycled after PSA hydrogen extraction or "steam conversion hydrogen production+PSA hydrogen extraction" and then pressurized and returned to the hydrogenation reaction process.

The higher the concentration of the new hydrogen, the better, generally not less than 95% (v), and most preferably not less than 99% (v), the more preferably the new hydrogen is fed to the hydrogenation section to replenish the hydrogen consumed during the hydrogenation reaction. All of the fresh hydrogen may be introduced into any of the hydrogenation reaction sections, preferably into the first hydrogenation reactor.

In the invention, in any reaction process, the hydrogen flow used can be all new hydrogen, can be all circulating hydrogen and can be the mixture of the new hydrogen and the circulating hydrogen.

Claims

1. A method for separating diesel oil from cold high-separation products of heavy oil suspension bed hydrocracking, comprising the following steps:

2. The method according to claim 1, characterized in that:

3. The method according to claim 1, characterized in that:

in the separation system KC3301, in the first diesel light component removal process, the first diesel liquid is separated into a first diesel light component removal process gas rich in naphtha component and a first diesel light component removal process base oil lean in naphtha component.

4. A method according to claim 3, characterized in that:

in a separation system KC3301, in a first diesel oil light component removal process, separating a first diesel oil liquid into a first diesel oil light component removal process gas rich in naphtha components and a first diesel oil light component removal process base oil lean in naphtha components;

at least a portion of the first diesel light ends process vapor is returned to the column section of the fractionation column of slurry pressure relief separation process C3121 above the discharge of the first diesel liquid.

5. The method according to claim 1, characterized in that:

in the high-pressure separation process S120, the material flow based on the hot high-pressure gas S110V is separated into the hot high-pressure gas S120V and the high-pressure oil S120L;

6. The method according to claim 5, wherein:

the warm low pressure separation process S220 is performed in combination with the hot low pressure separation process S210;

7. The method according to claim 1, characterized in that:

removing at least a part of naphtha components and components with lower boiling points from a stream based on cold high-fraction oil S130L in a separation system KC3301 to obtain first diesel-rich oil mainly composed of diesel components and containing wax oil components;

(2) removing more than 50% by weight of the naphtha component;

(3) more than 95% by weight of the naphtha component is removed.

8. The method according to claim 1 or 2, characterized in that:

the operating conditions of each step are as follows:

(1) asphaltene weight concentration greater than 12%;

(2) the Kangshi carbon residue value is higher than 16%;

(3) the weight content of organic sulfur is higher than 0.5%;

(4) the organic nitrogen weight content is higher than 0.15%;

(5) the weight content of the organic metal is higher than 0.015%;

the circulation ratio K100 is 0.40-2.5;

9. The method according to claim 5, wherein:

the operation conditions of the high-temperature and high-pressure separation process S120 are as follows: the temperature is 285-400 ℃ and is 30-130 ℃ lower than the operation temperature of the thermal high-pressure separation process S110, and the pressure is 8.0-25.0 MPa;

10. The method according to claim 1 or 2 or 5, characterized in that:

after the slurry is decompressed and separated in the process C3121, the circulation ratio K100 is selected from one of the following conditions:

①≤0.80；

②0.80～1.20；

③1.20～1.60；

④1.60～2.50；

⑤≥2.50。

11. the method according to claim 1, characterized in that:

and in the system of the pre-flash tower C3101, a material flow based on the hot low-pressure gas S210V enters the bottom of the pre-flash tower C3101 to flow upwards, is mixed with reflux liquid in the tower to be contacted, and is separated into pre-flash tower bottom oil C3101-BOTL and rising gas in the pre-flash tower C3101;

12. The method according to claim 11, wherein:

13. The method according to claim 11, wherein:

in the upper section of the pre-flash tower C3101, a side-line light oil extraction port of the pre-flash tower C3101 is arranged, and the side-line light oil of the pre-flash tower C3101 mainly consists of diesel oil components, does not contain or only contains a small amount of light wax oil components, and contains naphtha components.

14. The method according to claim 13, wherein:

the second side column is used in the process of removing the light components from the side light oil of the pre-flash column C3101, and the side light oil of the pre-flash column C3101 is separated into a gas separated from the side light oil of the pre-flash column C3101 which is rich in naphtha components, namely second side column overhead gas, and a liquid separated from the side light oil of the pre-flash column C3101 which is lean in naphtha components, namely second side column bottom oil.

15. The method according to claim 14, wherein:

at least a portion of the pre-flash column C3101 side-stream light oil separation vapor is returned to the column section of pre-flash column C3101 above the discharge outlet of pre-flash column C3101 side-stream light oil.

16. The method according to claim 1, characterized in that:

the material flow C3101-BOTL-X based on the pre-flash tower bottom oil C3101-BOTL enters a slurry vacuum separation process C3121, enters a position close to the composition of liquid phase material hydrocarbon in a vacuum fractionating tower mass transfer element, is mixed with the material passing through the vacuum fractionating tower mass transfer element, contacts with vapor phase material in the vacuum fractionating tower to complete partial or complete vaporization of the material flow C3101-BOTL-X, and then fractions with different boiling ranges enter 2 or more narrow fraction oils separated in a slurry vacuum flash steam separation process.

17. The method according to claim 1, characterized in that:

the mixed oil of the diesel oil component and the wax oil component separated in the slurry pressure reduction separation process C3121 is used as the washing oil material S110-WF used in the thermal high pressure separation process S110 and/or the washing material S120-WF of the thermal high pressure separation process S120.

18. The method according to claim 1, characterized in that:

the hydrocarbon oil composed of the main wax oil component separated in the slurry vacuum separation process C3121 is used as the washing oil material S210-WF used in the thermal low pressure separation process S210.

19. The method according to claim 1 or 2 or 5, characterized in that:

At least a portion of the stream comprising diesel components, wax oil components, based on the first diesel rich stream, enters a column section between a first diesel liquid discharge outlet and an adjacent liquid discharge outlet of a fractionation column used in slurry pressure reduction separation process C3121, and is mixed with material flowing in the column section.

20. The method according to claim 1 or 2 or 5, characterized in that:

at least a portion of the stream comprising diesel components, wax oil components, based on the first diesel rich stream, enters a column section between a first diesel liquid discharge outlet and an adjacent liquid discharge outlet of a fractionation column used in slurry pressure reduction separation process C3121, and is used as a cooling stream for the column section.

21. The method according to claim 1 or 2 or 5, characterized in that:

at least a portion of the stream comprising diesel components, wax oil components, based on the first diesel rich stream, enters the column section between the first diesel liquid discharge outlet and the adjacent liquid discharge outlet below the first diesel liquid discharge outlet of the fractionation column used in slurry pressure reduction separation process C3121 as the uppermost cooling stream for the column section.

22. The method according to claim 1 or 2 or 5, characterized in that:

In the tower section between the first diesel oil liquid discharge outlet and the adjacent liquid discharge outlet below the first diesel oil liquid discharge outlet of the fractionating tower used in the slurry decompression separation process C3121, the circulating heat-taking oil 99L is discharged;

23. The method as claimed in claim 22, wherein:

24. The method according to claim 23, wherein:

25. The method according to claim 1 or 2 or 5, characterized in that:

taking out the circulating heat taking oil 88L in the slurry decompression separation process C3121 and in the slurry decompression flash steam separation process;

26. The method according to claim 25, wherein:

27. The method according to claim 23 or 25, characterized in that:

the heat exchange and temperature rise of the circulating heat taking oil 99L or the circulating heat taking oil 88L and the hot material flow existing in the separation process of the hot high-pressure oil S110L, wherein the hot material flow existing in the separation process of the hot high-pressure oil S110L is selected from one or more of the following:

(2) a hot stream present in a hot low-split gas separation column system;

28. The method according to claim 1, characterized in that:

the thermal high-pressure oil S110L is divided into a first branch thermal high-pressure oil S110L-1 and a second branch thermal high-pressure oil S110L-2;

29. The method according to claim 1, characterized in that:

in the heat exchange and temperature rising process of the cold high-fraction oil S130L or the depressurization flash oil thereof, the cold high-fraction oil S130L or the depressurization flash oil thereof exchanges heat with hot oil products and/or middle-section reflux oil discharged by the slurry depressurization separation process C3121 and/or with bottom oil discharged by the slurry depressurization separation process C3121.

30. The method according to claim 1, characterized in that:

the asphaltene-containing material obtained after the depressurization of the thermal high-pressure oil S110L is directly mixed with the petroleum-based oil containing wax oil component and residual oil component to realize rapid cooling stabilization.

31. The method according to claim 1, characterized in that:

the heat of the separation process of recovering heavy oil suspension bed hydrocracking generated oil in the heat exchange and temperature rising process of petroleum base oil products becomes thermal state petroleum base oil products, wherein the thermal state petroleum base oil products comprise a bottom oil heat exchange process discharged from a slurry decompression separation process C3121;

32. The method according to claim 1, characterized in that:

at least a part of hydrogen-rich gas based on cold high-pressure gas S130V is used as circulating hydrogen RH to be returned to the heavy oil suspension bed hydrocracking reaction process R10 for recycling, and the circulating hydrogen RH is obtained by one or more of the following modes:

33. The method according to claim 1 or 2 or 3 or 4 or 5, characterized in that:

the first diesel oil liquid or the first diesel oil light component removing process base oil obtained in the separation system KC3301, wherein the content of hydrocarbon components with conventional boiling points between 180 and 350 ℃ is 85 to 100 percent by weight.

34. The method according to claim 1 or 2 or 3 or 4 or 5, characterized in that:

after the slurry pressure-reducing separation process C3121 is performed, at least a part of the material flow based on the bottom oil of the pressure-reducing separation process is cooled and then is used as circulating quenching oil, and the circulating quenching oil is returned to the buffer space of the bottom oil of the pressure-reducing separation process C3121 to reduce the temperature of the liquid phase of the buffer space of the bottom oil of the pressure-reducing separation process.

35. The method according to claim 1 or 2 or 3 or 4 or 5, characterized in that:

in the slurry decompression separation process C3121, the material flow based on the hot low-pressure oil enters a separation process with the operation pressure of negative pressure after the heat enthalpy is increased by or without a heating furnace.

36. A method according to claim 3 or 4, characterized in that:

the first diesel oil light component removing fractionating tower used in the first diesel oil light component removing process of the separation system KC3301 is provided with stripping steam which enters the bottom of a mass transfer element in the tower, or a tower bottom reboiler is arranged, so that the purpose of removing light hydrocarbon components of the first diesel oil is realized.

37. The method according to claim 11 or 12 or 13, characterized in that:

obtaining a light oil separation product of the pre-flash tower C3101 in a system of the pre-flash tower C3101;

38. The method according to claim 11 or 12 or 13, characterized in that:

39. The method according to claim 11 or 12 or 13, characterized in that: