CN114381300A

CN114381300A - Heavy oil lightening method

Info

Publication number: CN114381300A
Application number: CN202011118883.8A
Authority: CN
Inventors: 蓝兴英; 石孝刚; 李大鹏; 高金森; 李海; 李宋林; 王成秀; 张玉明; 徐新昌; 闫斌
Original assignee: Hangzhou Hydrocarbon Energy Technology Research Co ltd; China University of Petroleum Beijing
Current assignee: Hangzhou Hydrocarbon Energy Technology Research Co ltd; China University of Petroleum Beijing
Priority date: 2020-10-19
Filing date: 2020-10-19
Publication date: 2022-04-22

Abstract

The present invention provides a method for lightening heavy oil, which comprises the following steps: entering hydrogen and a heavy oil raw material mixed with a catalyst into a hydrogenation reactor for hydrogenation reaction to obtain a hydrogenation reaction product; and performing fractional distillation on the obtained hydrogenation reaction product to obtain Light oil products and tail oil; carry out extraction treatment on the tail oil, so that the obtained extracted oil is returned to the hydrogenation reactor to participate in the hydrogenation reaction to form a cycle; wherein, the system for realizing the hydrogenation reaction is hydrogen with a size not larger than A dispersion system in which bubbles of 500 microns are dispersed in the oil phase in the hydrogenation reactor. The lightening method of the present invention can achieve higher conversion rate and has the advantages of simple process flow and the like.

Description

Heavy oil lightening method

Technical Field

The invention belongs to the field of petroleum processing, and particularly relates to a heavy oil lightening method.

Background

With continuous heavy and inferior petroleum resources, heavy oil becomes an important raw material for refineries, and the efficient conversion processing of inferior heavy oil resources to produce more clean light oil products becomes an important way for dealing with the shortage of petroleum resources. According to the change of the mass ratio of carbon to hydrogen of oil products in the processing process, the heavy oil upgrading process can be divided into two types of hydrogenation and decarburization, wherein the decarburization process mainly comprises the processes of catalytic cracking, delayed coking and the like, is the main processing process for upgrading the heavy oil at the present stage, and accounts for about 83% of the processing amount of the whole heavy oil, however, the coke yield is high, and precious carbon atoms in the heavy oil are difficult to be fully utilized, which is a major problem in the process; the hydrogenation process accounts for about 17% of the total heavy oil processing amount, and compared with the decarburization process, the hydrogenation process can basically realize 100% utilization of carbon atoms in the heavy oil, so the hydrogenation process gradually becomes a main development trend of heavy oil lightening.

At present, a heavy oil hydrogenation process mainly comprises fixed bed hydrogenation, fluidized bed hydrogenation and suspension bed hydrogenation processes, and is taken as general knowledge in the industry, the fixed bed hydrogenation process generally requires that the total metal content in raw oil is not higher than 150ppm (mu g/g), the carbon residue value is not higher than 15%, the asphaltene content is not higher than 5%, and the raw material adaptability is limited; the fluidized bed hydrogenation process needs continuous replacement of partial catalyst in the reactor, and has the problems of complex engineering equipment, poor operation stability and the like; the suspension bed hydrogenation process can process inferior heavy oil with relatively poorer properties, and has the advantages of larger conversion depth, higher yield of light oil, higher carbon residue removal rate, higher metal removal rate and the like compared with other hydrogenation processes.

The suspension bed hydrogenation process is a hydrogenation process in which a catalyst with a certain particle size is driven to move by adjusting the flow velocity of a fluid to form a gas-liquid-solid three-phase bed layer, so that hydrogen, raw oil and the catalyst are contacted to complete a hydrocracking reaction.

U.S. patent document US2011303580a1 discloses a slurry hydrocracking process in which one or more hydrocarbon feedstocks and a slurry hydrocracking catalyst comprising a carrier are combined as a feed to a slurry hydrocracking reaction zone; fractionating the effluent (product) from the slurry hydrogenation reaction zone to obtain a light vacuum gas oil, a heavy vacuum gas oil, a mixture comprising bitumen and a slurry hydrocracking catalyst; separating the pitch from at least a portion of the slurry hydrocracking catalyst, the slurry hydrocracking catalyst obtained after separation being contained in a suspension; the suspension is recycled back to the slurry hydrocracking reaction zone. The process aims to improve the utilization rate of the asphalt, and therefore, the proposal of separating the asphalt from the slurry hydrogenation catalyst after vacuum distillation is provided, although the process can realize the lightening of heavy oil to a certain extent, the process has the defects of low single-pass conversion rate, large tail oil circulation amount, high energy consumption, high operation cost and the like.

Another U.S. patent document US2016122663a1 discloses an integrated slurry hydrocracking process in which a heavy residual hydrocarbon feedstock and a hydrogen stream are introduced into a slurry hydrocracking zone, the heavy residual hydrocarbon feedstock is hydrocracked under slurry hydrocracking conditions over a shiny hydrocracking catalyst to form a slurry hydrocracked effluent (product), at least a portion of said effluent is introduced into a first end of a distillate hydrotreater and hydrogen is supplied to said first end, said at least a portion of the effluent is hydrotreated under hydrotreating conditions, the resulting hydrotreated product exits the distillate hydrotreater from a second end opposite the first end, the hydrotreated product is then separated into a liquid stream and a gaseous stream, and at least a portion of the gaseous stream containing hydrogen is recycled to the slurry hydrocracking zone. The process also has the problems of complex process flow, limited conversion rate and the like.

Chinese patent document CN001239929A discloses a normal pressure heavy oil suspension bed hydrogenation process using a multi-metal liquid catalyst, wherein the slurry after being fully mixed and heated enters a suspension bed hydrocracking reactor from the bottom, the top effluent of the reactor enters a high temperature and high pressure separation system for separation, a vapor phase material flow enters an on-line fixed bed hydrofining reactor, a liquid phase material flow enters a low pressure separation system, the liquid phase material flow of the low pressure separation system also enters a previous fixed bed hydrofining reactor, and the material flow after being hydrofined by the fixed bed finally enters a conventional separation system for separation to obtain various products. The process combines a suspension bed hydrocracking reactor and a fixed bed hydrofining reactor and needs to be matched with at least three stages of separation systems (a high-temperature high-pressure separation system, a low-pressure separation system, a conventional separation system and the like) to realize the lightening of heavy oil, and the whole process system and flow are complex, the energy consumption is high and the cost is high.

Chinese patent document CN107892941B discloses a heavy oil suspension bed hydrocracking method, in the method, an inferior heavy oil suspension bed hydrogenation catalyst and inferior heavy oil are mixed uniformly and then enter a suspension bed hydrogenation reactor, then the reactor is heated to 320-500 ℃ for hydrogenation reaction, the reaction pressure is 5-20 MPa, the time is 0.5-4h, the hydrogen-oil volume ratio is 100-2000, and the space velocity is 0.2-4.0h^-1(ii) a Wherein, the hydrogenation catalyst consists of zinc oxide powder (with the content of 10-56 wt%) and fluidized ore component powder, or the hydrogenation catalyst consists of zinc oxide powder (with the content of 10-56 wt%), vulcanized ore component powder and vulcanized micro-mesoporous lanthanum ferrite (with the content of 0.2-8 wt%). The method realizes the reaction by improving the hydrogenation catalystThe effect of lightening the heavy oil raw material is improved, but the special requirement on the catalyst also increases the cost and the complexity of the whole process flow, and the practical industrial application has greater limitation.

The heavy oil is lightened through the hydrogenation process, and no matter which hydrogenation process is adopted, the common mechanism of the system material is that hydrogen is firstly dispersed and dissolved in the heavy oil, and then is activated by the hydrogenation catalyst dissolved or dispersed in the heavy oil, and further reacts with the component to be reacted in the heavy oil, so that the heavy oil is hydrogenated and lightened. In the process, the full contact of the heavy oil raw material, hydrogen and the catalyst is realized, which is very important for ensuring the high efficiency of the heavy oil hydrogenation and is the common essence of the difficult problems in the implementation process of various hydrogenation processes. Taking the suspension bed hydrogenation process as an example, after hydrogen enters a suspension bed hydrogenation reactor in a bubble form, the hydrogen needs to be transferred to liquid-phase heavy oil through a bubble-heavy oil phase interface and then is activated by a catalyst dissolved (oil-soluble or water-soluble homogeneous catalyst) or dispersed (solid granular heterogeneous catalyst) in the heavy oil, under a certain operating pressure (mass transfer driving force), the mass transfer rate of the hydrogen to the heavy oil is determined by the phase interface area between the hydrogen bubbles and the heavy oil, while the size of the hydrogen bubbles dispersed in the heavy oil in the existing suspension bed hydrogenation reactor is generally not less than 5mm, which cannot provide enough phase interface area for the transfer of the hydrogen to the heavy oil, and because the bubbles are large, the buoyancy in the heavy oil is also large, the rising speed is fast, the retention time is short, and the hydrogen has insufficient time to contact and react with the heavy oil, sufficient hydrogen radicals which can quickly capture macromolecular radicals generated by heating heavy oil are difficult to supplement in time, heavy oil macromolecular radicals are easy to collide with each other to cause superposition and even coking, so that the existing suspension bed hydrogenation process is usually implemented under a large operating pressure (most of which is greater than 18MPa) to increase the mass transfer driving force of hydrogen to the heavy oil and relieve the problems of poor contact reaction between the hydrogen and the heavy oil, easy coking and the like, and the large operating pressure has high requirements on equipment, an operating process and the like, so that the industrial application of the suspension bed hydrogenation process is very limited.

In fact, the above-mentioned hydrogenation processes such as the suspension bed generally face the common problem that it is difficult to achieve full contact of the heavy oil, the hydrogen and the catalyst, which is also the essential reason that the processes have the defects of large operation pressure, harsh conditions and the like, although the above-mentioned suspension bed hydrogenation processes such as the above-mentioned reports can achieve effective conversion of the heavy oil or reduce the operation pressure of the suspension bed reactor to a certain extent by jointly adopting a plurality of reactors and/or improving the catalyst and the like, the processes generally face the problems of complicated whole process flow and the like, and the industrial application is limited.

Therefore, the development of a novel heavy oil lightening process can reduce the operation pressure, simplify the process flow and improve the industrial applicability while ensuring or even improving the heavy oil conversion rate, and has become a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a heavy oil lightening method which can realize high-efficiency conversion of heavy oil, and has simple process flow and strong industrial practicability.

The invention provides a method for lightening heavy oil, which comprises the following steps: hydrogen and a heavy oil raw material mixed with a catalyst enter a hydrogenation reactor to carry out hydrogenation reaction to obtain a hydrogenation reaction product; fractionating the obtained hydrogenation reaction product to obtain a light oil product and tail oil; extracting the tail oil, and returning the obtained extraction oil to the hydrogenation reactor to participate in the hydrogenation reaction to form circulation; wherein, the system for realizing the hydrogenation reaction is a dispersion system in which hydrogen is dispersed in an oil phase in the hydrogenation reactor by bubbles with the size not more than 500 microns.

The heavy oil lightening method provided by the invention adopts a hydrogenation reactor to lighten a heavy oil raw material, and hydrogen is dispersed in an oil phase in the hydrogenation reactor by bubbles with the size not more than 500 microns, a dispersion system (also can be called as a dispersion flow form) which takes an oil phase (liquid phase) of the heavy oil raw material as a continuous phase, a catalyst and highly dispersed hydrogen bubbles with the micron scale (not more than 500 microns) as a discrete phase is formed under the reaction state in the hydrogenation reactor, the reactor with the system or the form is called as a dispersion bed hydrogenation reactor, the hydrogenation reaction is carried out under the dispersion system state, the heavy oil raw material, the catalyst and the hydrogen can be fully contacted, the conversion rate and the yield of the heavy oil raw material are remarkably improved, the condensation and the coking of the heavy oil raw material are inhibited, and simultaneously, the raw materials are fully contacted, the hydrogenation reaction can be carried out under the conditions of lower operation pressure and the like, so that the reaction condition is more moderate, and the energy consumption and the cost are saved; in addition, on the basis of the dispersion system, extraction treatment is carried out on the tail oil, so that the extraction oil returns to the hydrogenation reactor to form circulation, the problems of rapid inactivation of the catalyst and the like caused by more substances such as difficult-to-convert asphaltine and coke contained in the tail oil can be avoided while deep cracking of the heavy oil raw material is realized, and the stable operation of the whole lightening system is further ensured.

It will be appreciated that the hydrogen bubbles dispersed in the oil phase described above are similar to spheres, and the above dimensions generally refer to the diameter of the hydrogen bubbles, and the methods of measurement and control are conventional. The hydrogen can be dispersed in the oil phase in the form of bubbles with the size not larger than 500 microns by using the conventional material micro-dispersion or bubble generation method in the field, for example, the feed (such as hydrogen and heavy oil raw material and/or tail oil) can be subjected to micro-dispersion treatment by using the conventional bubble generation device (or referred to as micro-element generation device) in the field, so that the hydrogen and the oil phase comprising the heavy oil raw material enter the hydrogenation reactor to carry out hydrogenation reaction in the dispersion system.

In general, the gas phase and the liquid phase may be passed through the infinitesimal generator together to form an infinitesimal dispersion system in which the gas phase (e.g., hydrogen) is dispersed in the liquid phase (e.g., heavy oil feedstock or a mixture of heavy oil feedstock and extraction oil) in the form of bubbles, or the gas phase may be fed separately through the infinitesimal generator, and when the gas phase (e.g., hydrogen in a separate feeding portion described below) is fed separately, the infinitesimal generator (e.g., a third infinitesimal generator described below) may be generally buried in the liquid phase, or the gas phase may be inserted into the interior of the hydrogenation reactor through the inlet of the infinitesimal generator and contacted with the liquid phase (e.g., oil in a second infinitesimal dispersion system described below) to facilitate the formation of bubbles dispersed in the liquid phase after the gas phase enters the hydrogenation reactor from the infinitesimal generator.

Specifically, in an embodiment of the present invention, the hydrogen gas obtained by dispersing the hydrogen gas and the oil phase including the heavy oil feedstock by the first infinitesimal generator may enter the hydrogenation reactor as a first infinitesimal dispersion system in which bubbles having a size of not greater than 500 μm are dispersed in the oil phase to form the dispersoid (i.e., the dispersoid in the reactor is formed by the first infinitesimal dispersion system entering the hydrogenation reactor). In the process of lightening, the main body flow directions of the gas phase (mainly hydrogen, cracked gas, product oil gas and the like) and the liquid phase (heavy oil raw material mixed with catalyst, generated light oil and the like) in the first infinitesimal dispersion system can be the same (uniform gravity field or uniform inverse gravity field) or opposite (gas phase is in the same direction of the gravity field and the liquid phase is in the opposite direction of the gravity field, or gas phase is in the opposite direction of the gravity field and the liquid phase is in the same direction of the gravity field). As a preferred embodiment, the first infinitesimal dispersion system can generally enter the hydrogenation reactor from the top or the bottom of the hydrogenation reactor, and under the process conditions of the invention, the main flow form of the liquid phase in the hydrogenation reactor and the solid phase materials such as coke and the like generated by the reaction and included in the liquid phase is close to the ideal plug flow, which is beneficial to the reaction and the operation stability of the whole system.

Alternatively, in another embodiment, a part of the hydrogen (denoted as a1 part of hydrogen) and the hydrogen obtained by dispersing the oil phase including the heavy oil feedstock by the second micro-element generator may enter the hydrogenation reactor as a second micro-element dispersion system in which bubbles with a size not greater than 500 micrometers are dispersed in the oil phase, and simultaneously, the remaining part of the hydrogen (denoted as a2 part of hydrogen) is treated by the third micro-element generator and enters the hydrogenation reactor to form the dispersion system together with the second micro-element dispersion system (i.e., the remaining part of the hydrogen is treated by the third micro-element generator and enters the hydrogenation reactor to form an oil phase in which bubbles with a size not greater than 500 micrometers are dispersed in the second micro-element dispersion system, so as to form the dispersion system). Specifically, the second infinitesimal generating device firstly disperses a part of hydrogen in the heavy oil raw material in bubbles with the size not larger than 500 microns to form the second infinitesimal dispersion system, and then feeds the second infinitesimal dispersion system; the third infinitesimal generation means disperses the remaining portion of hydrogen (i.e., the hydrogen of the separate feed portion) into the heavy oil feedstock in the second infinitesimal dispersion into the hydrogenation reactor as bubbles having a size of no greater than 500 microns, thereby forming the dispersion described above. Wherein, a1 part of hydrogen is generally controlled to be 10% -90% of the total feeding amount (mass) of hydrogen, and further can be 20% -50% or 20% -40%, for example, in a specific embodiment, 30% of hydrogen (i.e. a1 part of hydrogen) and the oil phase including the heavy oil raw material are dispersed by a second infinitesimal generator to form a second infinitesimal dispersion, the second infinitesimal dispersion enters the hydrogenation reactor, and the remaining 70% of hydrogen (i.e. a2 part of hydrogen) enters the hydrogenation reactor by a third infinitesimal generator to form the above-mentioned dispersion together with the second infinitesimal dispersion; the second infinitesimal dispersion and a2 part of hydrogen can enter the hydrogenation reactor from the top, middle and bottom of the hydrogenation reactor, and the specific entering positions can be the same or different.

Specifically, the above-mentioned infinitesimal generating device (i.e. the first infinitesimal generating device, the second infinitesimal generating device, the third infinitesimal generating device) may be selected from at least one of a microporous ceramic membrane infinitesimal generating device, a venturi-type infinitesimal generating device, and an ultrasonic cavitation device, and the size of the formed hydrogen bubbles can be generally adjusted by selecting a microporous ceramic membrane infinitesimal generating device with a certain aperture, or adjusting conditions (or parameters) such as the gas velocity of the venturi-type infinitesimal generating device/ultrasonic cavitation device, for example, when bubbles are generated by using a microporous ceramic membrane infinitesimal generating device with a pore diameter of 100 μm (wherein the pore diameter of the microporous ceramic membrane is 100 μm), the gas phase enters the liquid phase through the microporous ceramic membrane to form bubbles, and the size of the formed bubbles is generally considered to be also about 100 μm on average; when the Venturi-type micro-element generating device (or the ultrasonic cavitation device) is used for generating bubbles, the larger the gas velocity of the gas phase is, the larger the size of the formed bubbles is, and vice versa, and the bubbles with specific sizes can be formed by controlling the gas velocity.

Considering the weight reduction effect, the system operation stability, the operation difficulty and other factors, in one embodiment of the present invention, the size of the hydrogen bubbles may be 10-500 μm, further 50-350 μm, such as 100-.

According to the research of the invention, in the lightening process, the infinitesimal generating device and the hydrogenation reactor are jointly adopted, the whole heavy oil lightening system is simple and easy to operate, and the lightening effect on the heavy oil raw material can be obviously improved.

Through further research, the conditions of the hydrogenation reactor (i.e. hydrogenation reaction conditions) may be: the operating pressure is 6-15 MPa, further 8-15 MPa or 8-13 MPa, the reaction temperature is 420-480 ℃, further 450-470 ℃ and the weight hourly space velocity is 0.1-1.5 h^-1Further, the time can be 0.2 to 0.8h^-1The hydrogen-oil ratio is 600-2500 Nm³/m³Further, it may be 800-2000Nm³/m³Further, 1000 to 2000Nm may be used³/m³For example, it may be 1000-1500Nm³/m³The condition is favorable for hydrogenation reaction of heavy oil raw materials, improves the conversion rate and simultaneously is favorable for ensuring the running stability of the whole system.

Further, in the heavy oil feedstock mixed with the catalyst, the mass ratio of the catalyst to the heavy oil feedstock may be 0.5 to 3.0%, further 0.8 to 2.3%, and for example, 0.8 to 1.5% or 1 to 1.3%.

The catalyst may be a hydrogenation catalyst having hydrogenation activity and/or coking-inhibiting property, which is conventional in the art, and may be at least one selected from a homogeneous hydrogenation catalyst and a heterogeneous hydrogenation catalyst, for example, wherein the homogeneous hydrogenation catalyst may be at least one selected from an oil-soluble catalyst and a water-soluble catalyst, a raw material of the heterogeneous hydrogenation catalyst includes a carrier and a metal component (denoted as a first metal component) supported on the carrier, the carrier may be at least one selected from coal dust and activated carbon, and the metal component may be at least one selected from Fe, Co, Mo, Zn, and the like.

In a preferred embodiment of the present invention, the catalyst used may include the above heterogeneous hydrogenation catalyst, and under the process conditions of the present invention, the catalyst can achieve excellent catalytic effect, and has the advantages of cheap and easily available raw materials, simple preparation, low cost, and the like, and has great practical significance in industry.

Furthermore, in the heterogeneous hydrogenation catalyst, the mass content (mass fraction) of the first metal component can be 1-10%, which is beneficial to further improving the lightening effect of the heavy oil raw material.

Of course, homogeneous hydrogenation catalysts, or a mixture of homogeneous and heterogeneous hydrogenation catalysts, may also be employed in the present invention. Specifically, the oil-soluble catalyst may be at least one of an organic acid salt and an organic metal compound, the organic acid salt may be one or more selected from naphthenate, fatty acid salt of C2 or more, citrate, aromatic acid salt, tartrate, fatty group-substituted formate, fatty group-substituted phosphate, and the like, and the organic metal compound may be one or more selected from organic compounds such as acetylacetone compound, carbonyl compound, (sulfonated) phthalocyanine compound, cyclopentadienyl compound, EDTA compound, porphyrin compound, nitrile compound, and the like, and organic metal compounds formed from metals; the water-soluble catalyst may include a complex which is at least one of a heteropoly acid such as one or more of phosphomolybdic acid, homomolybdic acid, phosphotungstic acid, phosphovanadic acid, silicomolybdic acid, silicotungstic acid, silicovanadic acid, thiomolybdic acid, and the like, a complex of a carbonyl compound and a metal component (referred to as a second metal component), a second metal component such as at least one selected from Mo, Fe, Ni, Co, and the like, and/or an inorganic salt such as at least one selected from a heteropoly acid salt (such as a salt formed from the heteropoly acid as described above) which is generally specifically an ammonium salt or an alkali metal salt of the heteropoly acid, and a sulfate, a hydrochloride, a carbonate, a basic carbonate, a nitrate, and the like containing a metal component (referred to as a third metal component) which is generally a heteropoly acid salt or an alkali metal salt, and/or a third metal component which is specifically selected from Mo, a carbonyl compound, a metal component (referred to as a second metal component), Fe. At least one of Ni and Co.

In the process, when the catalyst is a homogeneous hydrogenation catalyst, the dispersion system in the hydrogenation reactor is a gas-liquid two-phase system; when the catalyst used comprises a heterogeneous hydrogenation catalyst (i.e. the catalyst used is a heterogeneous hydrogenation catalyst, or a mixture of a homogeneous hydrogenation catalyst and a heterogeneous hydrogenation catalyst), the above-mentioned dispersion system is a gas-liquid-solid three-phase system (but may also be referred to as a gas-liquid pseudo-two-phase system since the amount of catalyst used is generally small (i.e. the solid phase is small).

The present invention can mix the catalyst in the heavy oil feedstock by a method conventional in the art to form the above-mentioned heavy oil feedstock mixed with the catalyst, and is not particularly limited. In specific implementation, the catalyst is generally dispersed or dissolved in the heavy oil feedstock as uniformly as possible, for example, when a heterogeneous hydrogenation catalyst or other catalyst that is not soluble in the heavy oil feedstock is used, the catalyst can form a micro-element structure of solid particles with micron scale (e.g., the size of the hydrogen bubbles is equivalent to that of the above-mentioned hydrogen bubbles) and is uniformly dispersed in the heavy oil feedstock, so that a uniformly distributed dispersion system with the heavy oil as a continuous phase and the highly dispersed micron scale hydrogen bubbles and catalyst particles as discrete phases is formed in the hydrogenation reactor, which is more favorable for the reaction and the lightening effect.

In the invention, the tail oil can be distillate oil with the distillation range of more than 350 ℃ or more than 500 ℃ separated from hydrogenation reaction products, the distillate oil contains more substances such as asphaltene, coke and the like which are difficult to convert, the distillate oil is extracted by adopting a proper extraction solvent, extraction oil with most of non-ideal components such as the asphaltene and the like removed and raffinate oil containing the non-ideal components can be respectively obtained, the extraction oil is returned to a hydrogenation reactor for cycle processing, the improvement of the conversion rate of heavy oil raw materials and the stable operation of a lightening system are facilitated, and the raffinate oil tailings can be thrown outwards, such as used as fuel or raw materials for extracting metal elements.

According to the research of the present invention, the above extraction solvent may generally comprise a hydrocarbon solvent of C1-C5, such as one or more of propane, butane and pentane.

Through further research, the temperature of the extraction treatment can be 50-190 ℃; and/or the pressure of the extraction treatment can be 3-4 MPa; and/or, the volume ratio of the extraction solvent to the tail oil (i.e. the solvent ratio) during the extraction treatment can be 6-8: 1. Specifically, in a preferred embodiment of the present invention, when propane is used as the extraction solvent, the temperature of the extraction treatment may be 50 to 90 ℃, for example, 50 to 80 ℃ or 50 to 70 ℃ or 60 to 70 ℃; when butane is used as an extraction solvent, the temperature of the extraction treatment can be 100-140 ℃; when pentane is used as the extraction solvent, the temperature of the extraction treatment may be 50-190 ℃, for example, 100-.

Generally, the hydrogenation reaction product from the hydrogenation reactor mainly contains distillate oil including light oil and tail oil, and a mixture of cracked gas, coke and unreacted hydrogen, and in specific implementation, the hydrogenation reaction product flowing out (or output) from the hydrogenation reactor can be firstly put into a gas-liquid separator and other devices for gas-liquid separation to respectively obtain a gas-phase component (mainly mixed gas of the cracked gas and the hydrogen) and a liquid-phase component (the distillate oil and a small amount of coke mixed therein and the like); then the liquid phase components enter devices such as a fractionating tower (a distillation tower) and the like for fractionation treatment to obtain light oil products such as gasoline fractions (the fraction section of less than 200 ℃), diesel oil fractions (the fraction section of 200-350 ℃), wax oil fractions (the fraction section of 350-500 ℃) and the like and tail oil (the fraction section of more than 500 ℃), or obtain light oil products such as gasoline fractions (the fraction section of less than 200 ℃), diesel oil fractions (the fraction section of 200-350 ℃) and the like and tail oil (the fraction section of more than 350 ℃); wherein, hydrogen (recycle hydrogen) in the gas phase component can be further separated, and the hydrogen is mixed with fresh hydrogen for recycling; the hydrogenation reaction product may flow from a location at the top, middle, or bottom of the hydrogenation reactor. Of course, in the present invention, the hydrogenation reaction product may also flow out from a plurality of positions in the top, middle, bottom, etc. of the hydrogenation reactor, and the products flowing out from each position may generally have different fraction distributions (equivalent to the hydrogenation reactor performing a primary fractionation treatment on the hydrogenation reaction product), and may be further refined by a gas-liquid separation treatment, etc.

The gas-liquid separator may be one or more of hot high fraction, hot low fraction, cold high fraction and cold low fraction, and may be assembled with hydrogenation reactor, fractionating tower, etc. by conventional method in the art. The hydrogenation reactor of the present invention may be a conventional hydrogenation reactor in the art, such as a high pressure resistant hollow cylinder device without any internal components, or a high pressure resistant reaction device with one or more sections of circulating internal components or other internal components, etc.

Further, in the process of lightening, the mass ratio of the extraction oil returned to the hydrogenation reactor to the heavy oil raw material can be 0.1-0.7:1, further 0.2-0.5: 1.

The method of the present invention is particularly useful for upgrading heavy oil feedstocks having relatively high carbon residue values, relatively high heavy metal (e.g., nickel (Ni), vanadium (V), etc.) contents, and relatively high sulfur and nitrogen contents, and in one embodiment, the heavy oil feedstock has a conradson carbon residue value (CCR) of greater than 10 wt%, and/or a total heavy metal content of greater than 150 μ g/g. Specifically, the heavy oil feedstock may be, for example, one or more of low-quality heavy oil such as heavy oil, super heavy oil, oil sand bitumen, atmospheric heavy oil, vacuum residue, FCC oil slurry, and solvent deoiled bitumen, and derived low-quality heavy oil such as heavy tar and residue generated in a coal pyrolysis or liquefaction process, heavy oil generated in dry distillation of oil shale, and low-temperature pyrolysis liquid product in biomass.

The implementation of the invention has at least the following beneficial effects:

compared with the existing hydrogenation processes of a suspension bed and the like, the heavy oil hydrogenation process has the advantages of high conversion rate of heavy oil raw materials (up to 85 percent or even more than 90 percent), mild and non-harsh conditions such as operating pressure and the like, simple process flow and the like, has the advantages of easiness in operation, low cost and the like, and is beneficial to industrial production and application.

Drawings

FIG. 1 is a flow chart of a heavy oil upgrading process according to an embodiment of the present invention;

FIG. 2 is a flow chart of a heavy oil upgrading process according to another embodiment of the present invention;

description of reference numerals:

1: a infinitesimal generating device; 2: a hydrogenation reactor; 3: a gas-liquid separator; 4: a distillation column; 5: an extraction tower; a: hydrogen gas; b: a heavy oil feedstock mixed with a catalyst; c: a mixed gas of cracked gas and hydrogen; d: a gasoline fraction; e: a diesel fraction; f: a wax oil fraction; g1, g 2: tail oil; h: extracting oil; i: and (5) extracting residual oil.

Detailed Description

The present invention will be described in more detail with reference to examples. It is to be understood that the practice of the invention is not limited to the following examples, and that any variations and/or modifications may be made thereto without departing from the scope of the invention.

Example 1

This example provides a method for converting heavy oil into light oil, as shown in fig. 1, in which hydrogen gas a and a heavy oil raw material b mixed with a catalyst are introduced into a venturi-type micro-element generator 1 to be subjected to a dispersion treatment, thereby obtaining a micro-element dispersion system in which hydrogen gas is dispersed in the heavy oil raw material as bubbles having an average size of not more than 500 μm; the infinitesimal dispersion system enters a hydrogenation reactor 2 from the top of the hydrogenation reactor for hydrogenation reaction (the hydrogenation reaction system in the hydrogenation reactor is a dispersion system in which hydrogen is dispersed in an oil phase by bubbles of not more than 500 microns) to obtain a hydrogenation reaction product; the hydrogenation reaction product enters a gas-liquid separator 3 for gas-liquid separation to respectively obtain a gas-phase component (a mixed gas c of cracked gas and hydrogen) and a liquid-phase component; the liquid phase component enters a distillation tower 4 for fractionation to respectively obtain a gasoline fraction d below 200 ℃, a diesel fraction e at 200-350 ℃, a wax oil fraction f at 350-500 ℃ and tail oil g1 above 500 ℃; and tail oil g1 enters an extraction tower 5, is contacted with an extraction solvent for extraction treatment, and respectively obtains extraction oil h and raffinate oil i, so that the extraction oil h returns to the infinitesimal generation device 1 to participate in the dispersion treatment, and circulation is formed. Wherein, the hydrogen in the mixed gas c is separated and mixed with fresh hydrogen for recycling.

Example 2

As shown in fig. 2, the present embodiment provides a method for lightening heavy oil, which is different from embodiment 1 in that: and the liquid phase component enters a distillation tower 4 for fractionation to respectively obtain a gasoline fraction d below 200 ℃, a diesel fraction e between 200 and 350 ℃ and tail oil g2 above 350 ℃. The other conditions were the same as in example 1.

Application example 1

In the following test examples 1 and 2 and comparative examples 1 and 2, the heavy oil feedstock used was vacuum residue, and its properties are shown in table 1; the catalyst is a heterogeneous catalyst formed by loading iron element on activated carbon (carbon powder), and the mass fraction of the iron element in the catalyst is 5%.

Test example 1 and test example 2

Experimental example 1 and experimental example 2 were performed by the method for upgrading heavy oil of example 1, wherein the conditions of hydrogen bubble size (micro-scale), operating pressure, reaction temperature, space velocity, hydrogen-oil ratio, mass ratio of the catalyst to the heavy oil feedstock (catalyst addition amount) and the like of the dispersoid in the hydrogenation reactor are shown in table 2, and the product distribution in the product of the hydrogenation reaction is shown in table 3; wherein, the conditions for extracting and processing the tail oil g1 are as follows: the used extraction solvent is pentane, the extraction temperature is 165 ℃, the pressure is 3.5Mpa, and the solvent ratio is 6: 1; the mass ratio of the extraction oil returned to the hydrogenation reactor 2 to the heavy oil raw material is 0.2: 1.

Comparative examples 1 and 2

The heavy oil raw material is subjected to a lightening treatment (no extraction treatment is performed on tail oil) by using a conventional suspension bed hydrogenation process, conditions such as the size of hydrogen bubbles (infinitesimal scale), the operating pressure, the reaction temperature, the space velocity, the hydrogen-oil ratio, the mass ratio of the catalyst to the heavy oil raw material (the catalyst addition amount) and the like dispersed in the heavy oil raw material in the suspension bed reactor are shown in table 2, and the product distribution in the product of the hydrogenation reaction is shown in table 3.

TABLE 1 heavy oil feedstock Properties

TABLE 2 reaction conditions

Item	Test example 1	Test example 2	Comparative example 1	Comparative example 2
					Infinitesimal scale, mum	210	500	5000	5000
Operating pressure, Mpa	13	13	13	22
					Reaction temperature of	457	457	457	459
Weight hourly space velocity, h^-1	0.4	0.4	0.4	0.4
					Hydrogen to oil ratio, Nm³/m³	1200	1200	1200	2278
The addition amount of the catalyst is wt%	1.2	1.2	1.2	1.2

TABLE 3 Main product distribution

Application example 2

In the following test examples 3 and 4 and comparative examples 3 and 4, the heavy oil feedstock used was Sinkiang vacuum residue, the properties of which are shown in Table 4; the catalyst is a heterogeneous catalyst formed by loading iron element on activated carbon (carbon powder), and the mass fraction of the iron element in the catalyst is 5%.

Test example 3 and test example 4

Experimental example 3 and experimental example 4 were performed by the method for upgrading heavy oil of example 2, wherein the conditions of hydrogen bubble size (micro-scale), operating pressure, reaction temperature, space velocity, hydrogen-oil ratio, mass ratio of the catalyst to the heavy oil feedstock (catalyst addition amount) and the like of the dispersion system in the hydrogenation reactor are shown in table 5, and the product distribution in the product of the hydrogenation reaction is shown in table 6; wherein, the conditions for extracting and processing the tail oil g2 are as follows: the used extraction solvent is propane, the extraction temperature is 65 ℃, the pressure is 3.43Mpa, and the solvent ratio is 6: 1; the mass ratio of the extraction oil returned to the hydrogenation reactor 2 to the heavy oil raw material is 0.2: 1.

Comparative examples 3 and 4

The heavy oil feedstock was subjected to a lightening process (neither extraction treatment was performed on the tail oil) using a conventional suspension bed hydrogenation process, and conditions such as the size of hydrogen bubbles (micro-scale), the operating pressure, the reaction temperature, the space velocity, the hydrogen-oil ratio, the mass ratio of the catalyst to the heavy oil feedstock (catalyst addition) and the like dispersed in the heavy oil feedstock in the suspension bed reactor are shown in table 5, and the product distribution in the product of the hydrogenation reaction is shown in table 6.

TABLE 4 heavy oil feedstock Properties

TABLE 5 reaction conditions

Item	Test example 1	Test example 2	Comparative example 1	Comparative example 2
					Infinitesimal scale, mum	210	500	5000	5000
Operating pressure, MPa	13	13	13	22
					Reaction temperature of	457	457	457	459
Weight hourly space velocity, h^-1	0.4	0.4	0.5	0.5
					Hydrogen to oil ratio, Nm³/m³	1200	1200	1200	2278
The addition amount of the catalyst is wt%	1.2	1.2	1.2	1.2

TABLE 6 Main product distribution

The results show that at lower hydrogen to oil ratios (1200 Nm)³/m³) Under the conditions of operating pressure (13MPa) and the like, the test examples 1-4 can achieve excellent lightening effect, the conversion rate of heavy oil raw materials is up to more than 87%, and the conversion rate is far higher than that of the traditional suspension bed process (such as comparative examples 1 and 3); traditional suspensionThe floating bed hydrogenation process has very poor light-ends effect under the conditions of lower pressure, hydrogen-oil ratio and the like, and high pressure (22MPa) and high hydrogen-oil ratio (2278 Nm) such as comparative examples 2 and 4 are often needed for improving the light-ends effect³/m³) The conditions further show that the experimental examples 1 and 3 can still achieve the heavy oil raw material conversion rate equivalent to that of the comparative examples 2 and 4 under the conditions of far lower hydrogen-oil ratio, operation pressure and the like than those of the comparative examples 2 and 4, and have lower coke yield, so that the heavy oil lightening method can greatly reduce the conditions of operation pressure, hydrogen-oil ratio and the like, and has very obvious advantages compared with the conventional hydrogenation processes such as a suspended bed and the like; in addition, in the lightening process of the test examples 1 to 4, the whole system runs stably, and the method also has the advantages of simple process flow, easy operation and the like, and further ensures the industrial practicability of the heavy oil lightening method.

Claims

1. A method for lightening heavy oil, comprising: hydrogen and a heavy oil raw material mixed with a catalyst enter a hydrogenation reactor to carry out hydrogenation reaction to obtain a hydrogenation reaction product; fractionating the obtained hydrogenation reaction product to obtain a light oil product and tail oil; extracting the tail oil, and returning the obtained extraction oil to the hydrogenation reactor to participate in the hydrogenation reaction to form circulation;

wherein, the system for realizing the hydrogenation reaction is a dispersion system in which hydrogen is dispersed in an oil phase in the hydrogenation reactor by bubbles with the size not more than 500 microns.

2. A lightening process according to claim 1, wherein hydrogen gas obtained by subjecting hydrogen gas and an oil phase comprising a heavy oil feedstock to dispersion treatment by a first infinitesimal generator is introduced into the hydrogenation reactor as a first infinitesimal dispersion system in which bubbles having a size of not more than 500 μm are dispersed in the oil phase to form said dispersion system; returning the extracted oil to the first infinitesimal generating device to participate in the dispersion treatment to form circulation;

or,

enabling a part of hydrogen and hydrogen obtained by dispersing an oil phase containing a heavy oil raw material by a second infinitesimal generating device to enter a hydrogenation reactor in a second infinitesimal dispersion system in which bubbles with the size not more than 500 micrometers are dispersed in the oil phase, and enabling the rest part of hydrogen to enter the hydrogenation reactor by a third infinitesimal generating device to form the dispersion system together with the second infinitesimal dispersion system; and returning the extracted oil to the first infinitesimal generating device to participate in the dispersion treatment to form circulation.

3. A method for weight reduction according to claim 2, wherein said infinitesimal generating device is at least one selected from the group consisting of a microporous ceramic membrane infinitesimal generating device, a Venturi infinitesimal generating device, and an ultrasonic cavitation device.

4. A lightening process according to any one of claims 1 to 3, wherein said bubbles have a size of 10 to 500 μm.

5. A lightening process according to claim 1, wherein the conditions of said hydrogenation reactor are: the operating pressure is 6-15 MPa, the reaction temperature is 420-480 ℃, and the weight hourly space velocity is 0.1-1.5 h^-1The hydrogen-oil ratio is 600-2500 Nm³/m³。

6. A lightening process according to claim 1 or 5, wherein the catalyst is present in an amount of 0.5 to 3.0% by mass based on the heavy oil feedstock.

7. A lightening process according to claim 1 or 6, wherein said catalyst is selected from at least one of a homogeneous hydrogenation catalyst and a heterogeneous hydrogenation catalyst; wherein,

the homogeneous hydrogenation catalyst is selected from at least one of oil-soluble catalyst and water-soluble catalyst;

the heterogeneous hydrogenation catalyst comprises a carrier and a metal component loaded on the carrier, wherein the carrier is selected from at least one of coal dust and activated carbon, and the metal component is selected from at least one of Fe, Co, Mo and Zn.

Preferably, in the heterogeneous catalyst, the mass content of the metal component is 1-10%.

8. A method for reducing the weight of oil products according to claim 1, wherein said tail oil is subjected to an extraction treatment using an extraction solvent comprising a hydrocarbon solvent of C1-C5.

Preferably, the temperature of the extraction treatment is 50-190 ℃; and/or the pressure of the extraction treatment is 3-4 MPa; and/or the volume ratio of the extraction solvent to the tail oil is 6-8: 1.

9. A lightening process according to claim 1 or 8, wherein the mass ratio of the extracted oil returned to the hydrogenation reactor to the heavy oil feedstock is from 0.1 to 0.7: 1.

10. A lightening process according to any one of claims 1 to 9, wherein the heavy oil feedstock is one or a mixture of more of heavy oil, ultra-heavy oil, oil sand bitumen, atmospheric heavy oil, vacuum residue, FCC slurry oil, solvent de-oiled bitumen, heavy tar and residue from coal pyrolysis or liquefaction processes, heavy oil from dry distillation of oil shale, and low temperature pyrolysis liquid products from biomass.