CN114437813A - Heavy oil lightening method - Google Patents

Abstract

The invention provides a method for lightening heavy oil, which comprises: dispersing hydrogen and heavy oil raw material mixed with catalyst through a micro-element generating device to form a micro-element dispersion system in which hydrogen is dispersed in the heavy oil raw material with bubbles with a size not greater than 500 microns ; Make the micro-element dispersion system enter the hydrogenation reactor to carry out hydrogenation reaction to obtain a hydrogenation reaction product; after the hydrogenation reaction product is output from the hydrogenation reactor, a part is returned to the hydrogenation reactor to form a circulation, and the remaining part is It is a light product. 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 method for lightening heavy oil.

Background technique

With the continuous increase and deterioration of petroleum resources, heavy oil has become an important raw material for refineries. The efficient conversion and processing of inferior heavy oil resources to produce more clean and light oil products has become an important way to cope with the shortage of petroleum resources. According to the change of the hydrocarbon mass ratio of the oil during the processing, the lightening process of heavy oil can be divided into two categories: hydrogenation and decarburization. Among them, the decarburization process mainly includes catalytic cracking, delayed coking and other processes, which is the most important process at this stage. The main processing technology for the lightening of heavy oil accounts for about 83% of the total processing volume of heavy oil. However, the high yield of coke and the difficulty of fully utilizing the precious carbon atoms in heavy oil are the main problems of this process. ; The hydrogenation process accounts for about 17% of the total heavy oil processing volume. Compared with the decarburization process, the hydrogenation process can basically utilize 100% of the carbon atoms in the heavy oil, so it has gradually become the lightening of heavy oil. main trends.

At present, the heavy oil hydrogenation process mainly includes fixed bed hydrogenation, ebullated bed hydrogenation and suspended bed hydrogenation process. As a common knowledge in the industry, the fixed bed hydrogenation process generally requires that the total metal content in the feed oil is not high. At 150ppm (μg/g), the residual carbon value is not higher than 15%, and the asphaltene content is not higher than 5%, the raw material adaptability is limited; the fluidized bed hydrogenation process requires continuous replacement of part of the catalyst in the reactor, and there are engineering equipment Complexity, poor operational stability and other problems; the suspended bed hydrogenation process can process inferior heavy oil with relatively poor properties. Compared with other hydrogenation processes, it has the advantages of larger conversion depth, higher light oil yield, carbon residue removal rate and removal rate. High metal rate and other advantages.

The suspended bed hydrogenation process refers to the hydrogenation process in which the catalyst with a certain particle size is driven by adjusting the fluid flow rate to form a gas, liquid, and solid three-phase bed, so that the hydrogen, the feed oil and the catalyst are contacted to complete the hydrocracking reaction. As the mainstream research direction of heavy oil hydrogenation at this stage, researchers have done a lot of research and exploration on the suspended bed hydrogenation process, and there are also some reports on the suspended bed hydrogenation process.

US patent document US2011303580A1 discloses a slurry hydrocracking process in which one or more hydrocarbon feedstocks and a slurry hydrocracking catalyst comprising a support are combined as a feedstock in a slurry hydrocracking reaction zone. feed; will fractionate the effluent (product) of the slurry hydrogenation reaction zone to obtain mild vacuum gas oil, heavy vacuum gas oil, a mixture comprising bitumen and a slurry hydrocracking catalyst; from at least a portion of the The pitch is separated from the slurry hydrocracking catalyst, and the slurry hydrocracking catalyst obtained after separation is contained in a suspension; the suspension is recycled back to the slurry hydrocracking reaction zone. The purpose of this process is mainly to improve the utilization rate of asphalt, so the above-mentioned scheme of separating asphalt from slurry hydrogenation catalyst after vacuum distillation is proposed, although this process can achieve lightening of heavy oil to a certain extent , but there are shortcomings such as low conversion rate per pass, large amount of tail oil circulation, high energy consumption, and high operating costs.

Another U.S. patent document US2016122663A1 discloses an integrated slurry hydrocracking process. In the process, heavy residual hydrocarbon feedstock and hydrogen stream are introduced into the slurry hydrocracking zone. Residual hydrocarbon feedstock is hydrocracked over a glossy hydrocracking catalyst to form a slurry hydrocracking effluent (product), and at least a portion of said effluent is introduced into the first end of the distillate hydrotreater and sent to the first end of the distillate hydrotreater. The first end is supplemented with hydrogen, the at least a portion of the effluent is hydrotreated under hydrotreating conditions, and the resulting hydrotreated product flows out of the distillate hydrotreater from a second end opposite the first end, and then The hydrotreated product is separated into a liquid stream and a gas stream, and at least a portion of the hydrogen-containing gas stream is recycled back to the slurry hydrocracking zone. The process also has the problems of complex process flow and limited conversion rate.

Chinese patent document CN001239929A discloses an atmospheric heavy oil suspended bed hydrogenation process using a multi-metal liquid catalyst. In the scheme, the fully mixed and heated slurry enters the suspended bed hydrocracking reactor from the bottom. The top effluent enters the high-temperature and high-pressure separation system for separation, the vapor-phase stream enters the online fixed-bed hydrotreating reactor, and the liquid-phase material enters the low-pressure separation system, and the liquid-phase material of the low-pressure separation system also enters the previous fixed-bed hydrogenation process. In the refining reactor, the stream after hydrorefining in the fixed bed finally enters the conventional separation system for separation to obtain various products. The process combines a suspended bed hydrocracking reactor and a fixed bed hydrotreating reactor and needs to cooperate with at least three-stage separation systems (high temperature and high pressure separation system, low pressure separation system, conventional separation system, etc.) to achieve light weight for heavy oil. The whole process system and process are complex, the energy consumption is high and the cost is high.

Chinese patent document CN107892941B discloses a heavy oil suspended bed hydrocracking method. In the method, the inferior heavy oil suspended bed hydrogenation catalyst and inferior heavy oil are mixed uniformly and then enter the suspended bed hydrogenation reactor, and then the reactor is heated to 320～ The hydrogenation reaction is carried out at 500°C, the reaction pressure is 5-20MPa, the time is 0.5-4h, the volume ratio of hydrogen to oil is 100-2000, and the space velocity is 0.2-4.0h ^-1 ; wherein, the hydrogenation catalyst is composed of zinc oxide. Powder (content is 10-56wt%) and fluidized ore component powder, or the hydrogenation catalyst is composed of zinc oxide powder (content is 10-56wt%), sulfided ore component powder and sulfided Micro-mesoporous lanthanum ferrite (content is 0.2-8wt%). This method improves the lightening effect of heavy oil feedstock by improving the hydrogenation catalyst, but its special requirements for the catalyst also increase the cost and complexity of the entire process flow, and the actual industrial application has great limitations.

The lightening of heavy oil is achieved by hydrogenation process. No matter which hydrogenation process is used, the common mechanism of system materials is that hydrogen is first dispersed and dissolved in heavy oil, and then is dissolved or dispersed in the hydrogenation catalyst in heavy oil. It is activated and then reacts with the components to be reacted in the heavy oil to realize the hydrogenation lightening of the heavy oil. In this process, realizing the full contact of the heavy oil raw material, hydrogen and catalyst is crucial to ensure the efficient hydrogenation of heavy oil, and it is also the common essence of the difficulties faced in the implementation of various hydrogenation processes. Taking the suspended bed hydrogenation process as an example to illustrate, after hydrogen enters the suspended bed hydrogenation reactor in the form of bubbles, it needs to be transferred to the heavy oil in the liquid phase through the bubble-heavy oil phase interface, and then be dissolved (oil-soluble or Water-soluble homogeneous catalysts) or dispersed (solid particulate heterogeneous catalysts) activated by catalysts in heavy oil, under a certain operating pressure (mass transfer driving force), the phase between hydrogen bubbles and heavy oil The interfacial area determines the mass transfer rate of hydrogen into the heavy oil, and the size of the hydrogen bubbles dispersed in the heavy oil in the current suspended bed hydrogenation reactor is generally not less than 5 mm, which cannot provide enough phase interface for the transfer of hydrogen to the heavy oil. In addition, due to the large air bubbles, its buoyancy in the heavy oil is also large, the rise is fast, and the residence time is short, so that the hydrogen does not have sufficient time to contact and react with the heavy oil, and it is difficult to replenish enough in time to quickly capture the heavy oil. Hydrogen radicals of molecular radicals can easily cause heavy oil macromolecular radicals to collide with each other, causing superposition and even coking. Therefore, the current suspended bed hydrogenation process is often carried out under relatively large operating pressures (most of which are greater than 18MPa). In this way, the driving force for mass transfer of hydrogen to heavy oil is increased, and the above-mentioned problems such as poor contact reaction between hydrogen and heavy oil and easy coking are alleviated. However, higher operating pressures often require higher equipment and operating procedures, resulting in the suspended bed hydrogenation process. Its industrial application is very limited.

In fact, the above-mentioned suspended bed and other hydrogenation processes are generally faced with the common problem that it is difficult to achieve full contact between heavy oil, hydrogen and catalyst, which is also the essential reason for these processes to have defects such as high operating pressure and harsh conditions. The reported suspended bed hydrogenation process can achieve effective conversion of heavy oil or reduce the operating pressure of the suspended bed reactor to a certain extent by combining multiple reactors and/or improving catalysts. Due to the complexity of the whole process, the industrial application is limited.

Therefore, developing a new heavy oil lightening process, while ensuring or even improving the conversion rate of heavy oil, reduces the operating pressure, simplifies the process flow, and improves its industrial practicability, has become a technical problem to be solved urgently by those skilled in the art.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method for lightening heavy oil, 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. ; Make the micro-element dispersion system enter the hydrogenation reactor for hydrogenation reaction to obtain the hydrogenation reaction product; after the hydrogenation reaction product is output from the hydrogenation reactor, a part is returned to the hydrogenation reactor to form a cycle, and the remaining part is Lightweight product.

The method for lightening heavy oil provided by the present invention combines the use of a micro-element generating device and a hydrogenation reactor. Micron-scale (not greater than 500 microns) hydrogen bubbles are a dispersed system of discrete phases (also known as a dispersed flow form, the present invention refers to a reactor with this system or form as a dispersed bed hydrogenation reactor), and at the same time a part of The hydrogenation reaction product is circulated back into the hydrogenation reactor, which can intensify the fluid disturbance in the hydrogenation reactor, strengthen the back-mixing and dispersion of hydrogen in the hydrogenation reactor, and enhance the dispersion flow shape in the hydrogenation reactor. Carrying out the hydrogenation reaction in the state of the dispersion system can make the heavy oil raw material, catalyst and hydrogen fully contact, significantly improve the conversion rate of the heavy oil raw material, and suppress the condensation of the heavy oil raw material to form coke; at the same time, due to the above dispersion Under the system, the raw materials are fully contacted, and the hydrogenation reaction can also be carried out under conditions such as lower operating pressure, so that the reaction conditions are more moderate, and energy consumption and cost are saved.

Specifically, in an embodiment of the present invention, the above-mentioned part of the hydrogenation reaction product (that is, the hydrogenation reaction product returned to the hydrogenation reactor for circulation) may be the total mass of the hydrogenation reaction product output from the hydrogenation reactor 10 to 90% of the hydrogenation reaction product (that is, after the hydrogenation reaction product is output from the hydrogenation reactor, 10 to 90% of the hydrogenation reaction product can be returned to the hydrogenation reactor to form a cycle, and the remaining part is used as a light product), and further can It is 20-80%, such as 20-70% or 20-60% or 20-50% or 20-40%, which is beneficial to the conversion rate of heavy oil feedstock and the operation stability of the entire lightening system.

Further, the micro-element dispersion system can be made to enter the hydrogenation reactor from the bottom of the hydrogenation reactor, and after the hydrogenation reaction product is output from the hydrogenation reactor, a part of it is returned to the hydrogenation reactor from the middle of the hydrogenation reactor to form. This condition can make the flow direction of the main body in the hydrogenation reactor to be upward (that is, against the gravitational field), part of the hydrogenation reaction product is injected from the middle, and the upward and downward materials collide with each other, which further strengthens the dispersed flow form and can increase The residence time of hydrogen in the hydrogenation reactor increases the chance of its contact with the heavy oil raw material, which is beneficial to the lightening effect of the heavy oil raw material; wherein, the part of the hydrogenation reaction product is preferably injected downward from the middle of the hydrogenation reactor In the hydrogenation reactor, for example, the material inlet in the middle can be embedded into the interior of the hydrogenation reactor, and the feeding method is to spray the material downward, so that the part of the hydrogenation reaction product enters the hydrogenation from the material inlet in the middle inside the reactor.

The middle part of the above-mentioned hydrogenation reactor may specifically be a position that accounts for 10-50% of the total height of the hydrogenation reactor from the bottom of the hydrogenation reactor, further may be 20-50%, such as 20-40% or 20 to 30% of the position.

In the above process, the hydrogenation reaction product can be output from one or several places at the bottom, middle, and top of the hydrogenation reactor. In one embodiment, the hydrogenation reaction product is output from the top of the hydrogenation reactor, which contains unreacted hydrogen, and a part of the hydrogenation reaction product is returned to the hydrogenation reactor to form a circulation, which can further increase the amount of hydrogen in the hydrogenation reaction. The residence time in the reactor increases the contact opportunity with the heavy oil raw material, and further improves the hydrogenation reaction efficiency of the heavy oil raw material; The output is at the position, and the products flowing out from each position have different fraction distributions (that is, the hydrogenation reactor has carried out a preliminary separation treatment for the hydrogenation reaction products), generally from top to bottom, the output products are gradually increased. The product output from the bottom is generally rich in tail oil. In specific implementation, this part can be returned to the hydrogenation reactor to form a cycle, which further enhances the lightening degree of the heavy oil feedstock.

It can be understood that the hydrogen gas bubbles dispersed in the heavy oil feedstock are similar to spheres, and the above size generally refers to the diameter of the hydrogen gas bubbles, and the measurement and control methods are conventional means. Specifically, the above-mentioned micro-element generating device may be a conventional material micro-dispersion or bubble generating device in the art, for example, it may be selected from at least one of a micro-porous ceramic membrane micro-element generating device, a venturi-type micro-element generating device, and an ultrasonic cavitation device Generally, the size of the formed hydrogen bubbles can be controlled by selecting a microporous ceramic membrane microelement generating device with a certain pore size, or adjusting the conditions (or parameters) such as the gas velocity of the Venturi type microelement generating device/ultrasonic cavitation device, such as When bubbles are generated by using a microporous ceramic membrane micro-element generating device with a pore diameter of 100 μm (the pore diameter of the microporous ceramic membrane is 100 μm), the gas phase (such as the above hydrogen) enters the liquid phase (such as the above heavy oil raw material) through the microporous ceramic membrane ) to form bubbles, and it is generally believed that the size of the formed bubbles is also about 100 μm on average; when using a venturi-type micro-element generator (or ultrasonic cavitation device) to generate bubbles, the greater the gas velocity of the gas phase, the larger the size of the formed bubbles. Vice versa, bubbles of a specific size can be formed through gas velocity control. In specific implementation, the gas phase and the liquid phase can be entered into the micro-element generating device together to form a micro-element dispersion system in which the gas phase (eg, hydrogen) is dispersed in the liquid phase (eg, heavy oil raw material) in the form of bubbles.

Taking into account factors such as the effect of weight reduction, the stability of system operation, the difficulty of operation, etc., in an embodiment of the present invention, the size of the above-mentioned hydrogen gas bubbles can generally be 10-500 μm, and can be 50-350 μm, for example, it can be 100-300μm or 150-250μm, etc.

According to the research of the present invention, the conditions of the above-mentioned hydrogenation reactor (that is, the hydrogenation reaction conditions) can be: the operating pressure is 6-15MPa, further can be 8-15MPa or 8-13MPa, the reaction temperature is 420-480°C, and further The temperature may be 450-470°C, the weight hourly space velocity may be 0.1-1.5h ^-1 , further may be 0.2-0.8h ^-1 , the hydrogen oil ratio may be 600-2500Nm ³ /m ³ , further may be 800-2000Nm ³ /m ³ , and further can be 1000-2000Nm ³ /m ³ , such as 1000-1500Nm ³ /m ³ , this condition is beneficial to the hydrogenation reaction of heavy oil feedstock, improves the conversion rate, and also helps to ensure the stability of the entire system operation.

Further, in the above heavy oil raw material mixed with catalyst, the mass ratio of the catalyst to the heavy oil raw material can be 0.5-3.0%, further can be 0.8-2.3%, such as 0.8-1.5% or 1-1.3%.

The above-mentioned catalyst may be a conventional hydrogenation catalyst in the art with hydrogenation activity and/or with coking-inhibiting properties, such as at least one selected from a homogeneous hydrogenation catalyst and a heterogeneous hydrogenation catalyst, wherein the homogeneous hydrogenation catalyst The hydrogen catalyst can be selected from at least one of oil-soluble catalysts and water-soluble catalysts. The compositional raw materials of the heterogeneous hydrogenation catalyst include a carrier and a metal component (referred to as the first metal component) supported on the carrier. From at least one of pulverized coal and activated carbon, the first metal component may be selected from at least one of Fe, Co, Mo, Zn, and the like.

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

Further, in the above heterogeneous hydrogenation catalyst, the mass content (mass fraction) of the first metal component may be 1-10%, which is beneficial to further improve the lightening effect of the heavy oil feedstock.

Of course, the present invention can also use a homogeneous hydrogenation catalyst, or a mixture of a homogeneous hydrogenation catalyst and a heterogeneous hydrogenation catalyst. Specifically, the above-mentioned oil-soluble catalyst can be at least one of organic acid salts and organic metal compounds, and the organic acid salts can be selected from naphthenic acid salts, fatty acid salts above C2, citrates, aromatic acid salts, One or more of tartrate, aliphatic-substituted formate, aliphatic-substituted phosphate, etc., the organometallic compound can be, for example, acetylacetonate, carbonyl compound, (sulfonated) phthalocyanine compound, cyclopentanediol One or more of the organometallic compounds formed by organic compounds such as alkenyl compounds, EDTA compounds, porphyrins, nitrile compounds and metals; the above-mentioned water-soluble catalysts may include complexes and/or inorganic salts. For example, the complex can be at least one of the complexes formed by a heteropoly acid, a carbonyl compound and a metal component (referred to as the second metal component), and the heteropoly acid can be, for example, phosphomolybdic acid, high molybdenum One or more of acid, phosphotungstic acid, phosphovanadic acid, silico-molybdic acid, silicotungstic acid, silico-vanadic acid, thiomolybdic acid, etc. The second metal component can be selected from Mo, Fe, Ni, Co At least one of the above, the inorganic salt can be selected from heteropoly acid salts (such as salts formed by the above-mentioned heteropoly acids, etc.) and sulfates, hydrochloric acid containing metal components (denoted as the third metal component) At least one of salts, carbonates, basic carbonates, nitrates, etc., the above-mentioned heteropolyacid salts can generally be heteropolyacid ammonium salts or alkali metal salts, etc., and the third metal component can be selected from At least one of Mo, Fe, Ni, Co, and the like.

In the above-mentioned process, when the used catalyst is a homogeneous hydrogenation catalyst, the dispersion system in the hydrogenation reactor is a gas-liquid two-phase system; when the used catalyst contains a heterogeneous hydrogenation catalyst (being 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 because the amount of catalyst is generally less (that is, the solid phase is less), it can also be used. It is called a gas-liquid pseudo-two-phase system).

In the present invention, the catalyst can be mixed into the heavy oil feedstock by the conventional method in the art to form the above-mentioned heavy oil feedstock mixed with the catalyst, which 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 catalyst such as a heterogeneous hydrogenation catalyst that cannot be dissolved in the heavy oil feedstock is used, it can be made to form micron-sized (such as and hydrogen gas bubbles). The micro-structures such as solid particles with similar size) are uniformly dispersed in the heavy oil raw material, which is conducive to the formation of a uniformly distributed dispersion with heavy oil as the continuous phase and highly dispersed micron-scale hydrogen bubbles and catalyst particles as the discrete phase in the hydrogenation reactor. The system is more conducive to the progress of the reaction and the lightening effect.

In general, the hydrogenation reaction product from the hydrogenation reactor is mainly a mixture containing distillate oil including light oil and tail oil, as well as cracked gas, coke, and unreacted hydrogen, which is output from the hydrogenation reactor. Afterwards, a part is returned to the hydrogenation reactor for hydrogenation reaction (ie, a cycle is formed), and a part is used as a lightened product. In an embodiment of the present invention, it may also generally further include: separating the lightened product, and recycling the separated tail oil (that is, mixing the tail oil with fresh heavy oil raw material as the heavy oil raw material for the above-mentioned lightening process) , the control cycle ratio (mass ratio of tail oil/fresh heavy oil raw material) is 0.1 to 0.7, and further can be 0.2 to 0.5, which is conducive to the high conversion of heavy oil raw materials; in specific implementation, the tail oil can be removed first through devices such as liquid-solid separators The coke in it is returned to the circulation. Of course, the separated tail oil can also be thrown out, for example, used as fuel.

Specifically, the above-mentioned lightened product can be first entered into a device such as a gas-liquid separator for gas-liquid separation to obtain gas-phase components (mainly a mixture of cracked gas and hydrogen) and liquid-phase components (distillate oil and inclusions in Among them, a small amount of coke, etc.); then the liquid phase components are sent into devices such as fractionation towers (distillation towers) for fractionation treatment to obtain gasoline fractions (<200°C fractions), diesel fractions (200-350°C fractions), wax oil Fractions (350-500°C fractions), tail oil (>500°C fractions) and other products; wherein, the hydrogen (circulating hydrogen) in the above-mentioned gas phase components can be further separated, mixed with fresh hydrogen and recycled.

The above-mentioned gas-liquid separator can specifically be one or a combination of one or more of the hot high fraction, the hot low fraction, the cold high fraction, and the cold low fraction, and can be combined with a hydrogenation reactor, a fractionation tower, etc. by conventional methods in the art. Assemble. The hydrogenation reactor of the present invention can be a conventional hydrogenation reactor in the field, such as a high-pressure-resistant hollow cylinder device without any internal components, or a high-pressure-resistant hollow-tube device with one or more sections of loop internal components or other forms of internal components Reactor etc.

The method of the present invention can especially lighten the heavy oil feedstock with the characteristics of high residual carbon value, high content of heavy metals (such as nickel (Ni), vanadium (V), etc.) and high content of sulfur and nitrogen. In one embodiment, the heavy oil The Conrad Carbon Residue Value (CCR) of the raw material is greater than 10 wt%, and/or the total content of heavy metals is greater than 150 μg/g. Specifically, the above-mentioned heavy oil raw materials can be heavy oil, super heavy oil, oil sand asphalt, atmospheric heavy oil, vacuum residue oil, FCC oil slurry, solvent deoiled asphalt and other inferior heavy oil and heavy oil produced by coal pyrolysis or liquefaction process One or more mixtures of tar and residual oil, heavy oil produced by dry distillation of oil shale, and low-temperature pyrolysis liquid products of biomass.

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

The lightening method provided by the present invention is a novel heavy oil hydrogenation process driven by a micro-element dispersion system with a micron scale. Compared with the existing hydrogenation processes such as a suspended bed, the present invention has both a high conversion rate of heavy oil raw materials ( up to 80% or even more than 85%), the operating pressure and other conditions are not harsh, the technological process is simple, etc., and it has the advantages of easy operation and low cost, which is conducive to industrial production and application.

Description of drawings

Fig. 1 is the process flow diagram of the lightening process of heavy oil according to an embodiment of the present invention;

Description of reference numbers:

1: Micro element generator; 2: Hydrogenation reactor; 3: Gas-liquid separator; 4: Distillation column; a: Hydrogen; b: Heavy oil raw material mixed with catalyst; c1: Part of hydrogenation reaction product; c2: Remainder Partial hydrogenation reaction product (ie light product); d: mixture of cracked gas and hydrogen; e: gasoline fraction; f: diesel fraction; g: wax oil fraction; h: tail oil.

Detailed ways

The content of the present invention will be described in more detail below with reference to the embodiments. It should be understood that the implementation of the present invention is not limited to the following examples, and any modifications and/or changes made to the present invention will fall within the protection scope of the present invention.

Example 1

This embodiment provides a method for lightening heavy oil. As shown in FIG. 1 , hydrogen a and a heavy oil raw material b mixed with a catalyst are introduced into a micro-element generating device 1 for dispersion treatment to form hydrogen gas bubbles with a size of not more than 500 microns. The micro-element dispersion system dispersed in the heavy oil raw material; the micro-element dispersion system enters the hydrogenation reactor 2 from the bottom of the hydrogenation reactor to carry out hydrogenation reaction to obtain a hydrogenation reaction product; the hydrogenation reaction product is removed from the hydrogenation reactor. After the top of the hydrogenation reaction product is output, a part of the hydrogenation reaction product c1 (accounting for 30% of the total mass of the hydrogenation reaction product) is returned to the hydrogenation reactor from the middle of the hydrogenation reactor to form a cycle, and the remaining part of the hydrogenation reaction product c2 (accounting for the hydrogenation reaction product c2) 70% of the total mass of the reaction product) is the lightened product; the lightened product c2 enters the gas-liquid separator 3 for gas-liquid separation to obtain gas-phase components (mixed gas d of cracked gas and hydrogen) and liquid-phase components respectively. Components; liquid components enter the distillation tower 4 for fractionation, respectively obtaining gasoline fraction e < 200 ° C, diesel fraction f of 200 ~ 350 ° C, wax oil fraction g of 350 ~ 500 ° C and tail oil > 500 ° C h; wherein, the hydrogen in the mixed gas d is separated, and it is mixed with fresh hydrogen for recycling.

Specifically, c1 is injected downward into the hydrogenation reactor from the material inlet in the middle of the hydrogenation reactor, the material inlet is embedded in the interior of the hydrogenation reactor, and the feeding method is to spray the material downward; The bottom of the hydrogenation reactor accounts for about 25% of the total height of the hydrogenation reactor; the above-mentioned micro-element generating device 1 is a Venturi-type micro-element generating device.

Application Example

In the following test examples 1 and 2 and comparative examples 1 and 2, the heavy oil raw material used is vacuum residue, and its properties are shown in Table 1; the catalysts used are all heterogeneous catalysts formed from activated carbon (carbon powder) supported by iron elements , in the catalyst, the mass fraction of iron element is 5%.

Test Example 1 and Test Example 2

Using the method of lightening heavy oil in Example 1 to carry out Test Example 1 and Test Example 2, the hydrogen bubble size (micro-scale), operating pressure, reaction temperature, space velocity, hydrogen-to-oil ratio of the dispersion system in the hydrogenation reactor, Conditions such as the mass ratio of the catalyst to the heavy oil feedstock (the amount of catalyst added) are shown in Table 2, and the product distribution in the lightened product is shown in Table 3.

Comparative Example 1 and Comparative Example 2

The above heavy oil raw material is lightened by conventional suspended bed hydrogenation process. The size of hydrogen bubbles (micro-scale), operating pressure, reaction temperature, space velocity, hydrogen oil ratio, Conditions such as the mass ratio of the catalyst to the heavy oil feedstock (the amount of catalyst added) are shown in Table 2, and the product distribution in the lightened product is shown in Table 3.

Table 1 Properties of heavy oil raw materials

Table 2 Reaction conditions

project Test Example 1 Test Example 2 Comparative Example 1 Comparative Example 2 Micro-scale, μm 210 500 5000 5000 Operating pressure, MPa 13 13 13 twenty two Reaction temperature, °C 457 457 457 459 Heavy hourly airspeed, h^-1 0.4 0.4 0.4 0.4 Hydrogen oil ratio, Nm³/m³ 1200 1200 1200 2278 Amount of catalyst added, wt% 1.2 1.2 1.2 1.2

Table 3 Distribution of main products

Product distribution, wt% Test Example 1 Test Example 2 Comparative Example 1 Comparative Example 2 cracked gas 3.9 3.8 4.6 2.3 gasoline 11.5 8.4 5.1 20.2 diesel fuel 27.1 22.1 16.8 42.0 wax oil 47.1 44.7 34.7 22.7 tail oil 10.2 18.9 34.9 12.1 coke 0.2 2.1 3.9 0.7 total 100.0 100.0 100.0 100.0 Conversion rate 89.8% 81.1% 65.1% 87.9%

The results show that under the conditions of lower hydrogen oil ratio (1200Nm ³ /m ³ ) and operating pressure (13MPa), Test Example 1 and Test Example 2 can achieve excellent lightening effect, and the conversion rate of heavy oil feedstock is as high as 81% The above is much higher than the traditional suspended bed process (such as Comparative Example 1); the traditional suspended bed hydrogenation process has a very poor lightening effect under the conditions of lower pressure and hydrogen-oil ratio (such as Comparative Example 1). To improve the effect of lightening, high pressure (22MPa) and high hydrogen oil ratio (2278Nm ³ /m ³ ) such as Comparative Example 2 are often required. Further through Test Example 1 and Comparative Example 2, it is shown that Test Example 1 is far lower than Under the conditions such as hydrogen-oil ratio and operating pressure of Comparative Example 2, the conversion rate of heavy oil feedstock and low coke yield comparable to Comparative Example 2 can still be achieved, which shows that the method for lightening heavy oil of the present invention can greatly reduce operating pressure, The hydrogen-oil ratio and other conditions have obvious advantages compared to conventional hydrogenation processes such as suspended bed; in addition, during the lightening process of test examples 1 and 2, the entire system runs stably, and also has the advantages of simple process flow and easy operation, etc. The advantages further ensure that the method for lightening heavy oil of the present invention is beneficial to practical industrial application.

Claims (10)

1. a heavy oil lightening method, is characterized in that, comprises: make hydrogen and the heavy oil raw material mixed with catalyzer disperse through the micro element generating device, form hydrogen to be dispersed in the micro element in the heavy oil raw material with the bubble of size not more than 500 microns. element dispersion system; the micro element dispersion system enters the hydrogenation reactor for hydrogenation reaction to obtain a hydrogenation reaction product; after the hydrogenation reaction product is output from the hydrogenation reactor, a part of the hydrogenation reaction product is returned to the hydrogenation reactor to form a circulation , and the remaining part is the light product. 2 . The lightening method according to claim 1 , wherein the part of the hydrogenation reaction product accounts for 10-90% of the total mass of the hydrogenation reaction product output from the hydrogenation reactor. 3 . 3. The method for lightening according to claim 1 or 2, wherein the micro-element dispersion system enters the hydrogenation reactor from the bottom of the hydrogenation reactor, and the part of the hydrogenation reaction product is obtained from the hydrogenation reactor. The middle of the reactor is returned to the hydrogenation reactor to form the cycle. 4 . The method for lightening according to claim 1 , wherein the micro-element generating device is selected from at least one of a micro-porous ceramic membrane micro-element generating device, a venturi-type micro-element generating device, and an ultrasonic cavitation device. 5 . kind. 5 . The lightening method according to claim 1 or 4 , wherein the size of the bubbles is 10-500 μm. 6 . 6 . The lightening method according to claim 1 , wherein the conditions of the hydrogenation reactor are as follows: the operating pressure is 6-15 MPa, the reaction temperature is 420-480° C., and the weight hourly space velocity is 0.1-1.5 h ^-1 , the hydrogen oil ratio is 600-2500Nm ³ /m ³ . 7 . The lightening method according to claim 1 or 6 , wherein the mass ratio of the catalyst to the heavy oil raw material is 0.5-3.0%. 8 . 8. The lightening method according to claim 1 or 7, wherein the 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 catalysts and water-soluble catalysts; The raw materials of the heterogeneous hydrogenation catalyst include a carrier and a metal component supported on the carrier, the carrier is selected from at least one of pulverized coal and activated carbon, and the metal component is selected from Fe, Co, Mo, Zn at least one of them. Preferably, in the heterogeneous catalyst, the mass content of the metal component is 1-10%. 9 . The lightening method according to claim 1 or 6 , further comprising: performing separation on the lightening product, circulating the separated tail oil, and controlling the circulation ratio to be 0.1-0.7. 10 . 10. The lightening method according to any one of claims 1-9, wherein the heavy oil raw material is heavy oil, super heavy oil, oil sand asphalt, atmospheric heavy oil, vacuum residue oil, FCC oil One or more mixtures of slurry, solvent deoiled asphalt, heavy tar and residual oil produced by coal pyrolysis or liquefaction, heavy oil produced by dry distillation of oil shale, and low temperature pyrolysis liquid products in biomass.

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