RU2805925C1 - Method for combined hydrocracking of heavy petroleum feedstock, including isolation of spent additive from unconverted hydrocracking residue and its drying - Google Patents

Abstract

FIELD: oil refining.

SUBSTANCE: method for processing heavy petroleum feedstock, which includes stages in which: hydrocracking of the feedstock is carried out in a suspension phase (HSP), including heavy petroleum feedstock and a coal additive, followed by separation into a feedstock flow subjected to HSP and a heavy residue flow, wherein the heavy residue flow is a suspension of unconverted high-boiling residue and spent coal additive; hydrocracking of hydrocracking products of raw materials obtained at the HSP stage is carried out in the gas phase with a stationary layer of catalyst, followed by fractionation of the resulting hydrocracking products; performing a method for purifying an unconverted hydrocracking residue of a heavy petroleum feedstock from a spent coal additive to obtain a spent coal additive and a purified unconverted hydrocracking residue of a heavy petroleum feedstock. The invention also concerns a unit for separating the spent additive from the unconverted hydrocracking residue of heavy oil feedstock, a unit for drying the spent coal additive, a unit for regenerating the solvent and fractionating refined petroleum products, a method and system for purifying the unconverted hydrocracking residue of heavy oil feedstock from the spent coal additive.

EFFECT: increasing the efficiency of separation of the spent coal additive and the mixture of unconverted residue and solvent, ensure stable operation of equipment with a given performance and prevent clogging of equipment with deposits, which avoids long-term equipment downtime and labor-intensive work to clean equipment from deposits.

21 cl, 1 ex, 3 tbl, 9 dwg

Description

FIELD OF TECHNOLOGY TO WHICH THE INVENTION RELATES

The invention relates to the field of oil refining, in particular to a method for processing heavy petroleum feedstocks, which makes it possible to obtain valuable products from heavy oil refining residues, in particular to a method for hydrocracking heavy petroleum feedstocks, including the separation of solid additives from unconverted hydrocracking residues with their subsequent drying.

BACKGROUND OF THE ART

The prior art knows many processes for processing heavy hydrocarbons in the presence of special solid additives (adsorbents, catalysts, etc.), for example, VCC, Uniflex, EST, GT-SACT, H-Oil, LC-Fining, etc. The most effective Of these, for the processing of heavy oil raw materials, for example, such as tar obtained after the fractional distillation of heavy Urals oils, is combined hydrocracking. Solid additives, after fulfilling their function of adsorption of asphaltenes and their compaction products (carbenes and carboids), should be removed from unconverted residues to ensure the possibility of subsequent separate processing of the solid spent additive and unconverted residues to obtain demanded products.

The process of separating unconverted residues and solid additives is often complicated by the concentration and formation in the heavy residues of hydrocracking processes (heavy bottom products of high-pressure separators) of a large number of asphaltenes and their higher molecular weight derivatives - carbenes and carboids - which leads to an increase in the colloidal and aggregative instability of the residues, an increase their viscosity and density. A mixture of solid additives (catalysts, adsorbents, etc.) and asphaltenes is prone to the formation of highly viscous compounds, which in turn, during long-term storage at temperatures below 80°C, cake and turn into coke deposits of various types. In this case, chemical aging of heavy hydrocarbons occurs with their further precipitation.

As a result, the concentration of mechanical impurities and hydrocarbon sediments in the composition of heavy unconverted residues of hydrogenation processes is so high that this prevents further processing of residual hydrocracking products into commercial products (fuel oil, sintering additive, bitumen products, etc.). In addition, during transportation and storage of such residual products, clogging of process equipment occurs (pipes, heat exchange, pumping equipment, valves, gate valves, etc.). Clogging of equipment in such an industrial process leads to long-term equipment downtime and labor-intensive work to clean the equipment from deposits.

In this application, the term “hydrocarbon sediments” means a mixture of high molecular weight resins and heavy hydrocarbons, mainly consisting of asphaltenes, carbenes and carboids, which, due to the principles of colloidal chemistry, have low aggregative and colloidal stability and are prone to precipitation into a separate phase when external parameters change (temperature, pressure, etc.).

The quality requirements for marine fuels are described in ISO 8217. Very stringent requirements for aging residue are specified in ISO 10307-2 (also known as IP390), which must be less than or equal to 0.1%.

Requirements for the quality of bitumen products are prescribed in GOST 33133-2014. In addition to the basic physicochemical properties, solubility in toluene according to GOST 33133-2014 is very important, which must be at least 99% by weight, and which characterizes the content of toluene-insoluble mechanical impurities and asphaltene compaction products (carbenes and carboids) in bitumen products.

Patent RU 2 678 764 C2 describes a petroleum feedstock conversion method comprising a fluidized bed hydrocracking step, a holding step and a sediment separation step to produce liquid fuels with low sediment content. The disadvantages of this solution are: a) the need for a holding stage and its rather high duration in order to settle the heavy fraction obtained after the separation stage of hydrocracking products; and b) a general and too broad description of the stage of separating the sediment from the heavy fraction, which does not allow one to unambiguously solve the problem of asphaltene agglomeration when using solvents and aliphatic diluents.

Patent RU 2 337 938 C1 describes a method for separating hydrocarbons from a solid source. This method has significant limitations due to the use of water for mixing with bitumen rock. Firstly, bitumen may contain natural emulsifiers, which, when mixed with water and sufficiently mixed (for example, with pumping equipment), contributes to the formation of stable water-bitumen emulsions. Secondly, the use of water will not allow heating the mixture above 100°C, which reduces the efficiency of subsequent separation stages based on the difference in densities and viscosities of the separated media. Thirdly, the use of the separation methods proposed in the patent will not allow one to effectively separate the smallest particles of the solid phase (less than 100 microns in size).

Patent US2012/0048782 A1 also proposes a multi-stage cleaning of tar sands using two solvents, however, unlike previous solutions, it also includes a drying step for the separated solids. As a light solvent, it is proposed to use a hydrocarbon fraction of 36-110°C, containing hydrocarbons such as pentane, hexane, cyclohexane and heptane. When such solvents of a paraffin-naphthenic nature come into contact with heavy unconverted residues from hydrocracking processes of residual raw materials, which are highly viscous, dense (with a density at 15°C of more than 1100 kg/m ³ ) products with a high content of asphaltenes (up to 35-40% wt.) and high Conradson coking capacity (up to 35-40% by weight), asphaltene precipitation will undoubtedly occur, which in turn will lead to clogging of equipment with the formation of a large amount of coke-like sediment. A significant reduction in the efficiency of this method in relation to residual products of hydrocracking of residual raw materials is facilitated by too low mixing temperatures of bituminous sand with solvents (20-80°C). Thus, the methods proposed in US2012/0048782 A1 are poorly applicable to residues from secondary, deepening oil refining processes.

In addition, the patent RU 2 541 324 C2 discloses a process for hydroprocessing heavy feedstocks using an additive to capture catalytically active metals and other metals contained in the feedstock and concentrate them in the heavy stream or unconverted residual material leaving the process reactor. Also described herein is a process for separating the additive from the unconverted hydroprocessing residue using a centrifuge. The processes mentioned in this document are described with reference to laboratory tests, however, their implementation in industrial production may encounter a number of difficulties associated with the scalability of the described process and clogging of equipment with asphaltene deposits, and, consequently, low stability of equipment operation and efficiency of purification of unconverted residue from the additive .

Thus, the problem facing the present invention is to create a system and method for separating solid additives from unconverted slurry hydrocracking residues of heavy petroleum feedstocks with their subsequent drying, ensuring stable operation of equipment with a given productivity and preventing equipment from clogging with deposits.

In addition, the problem facing the present invention is the creation of an effective and stable method for hydrocracking heavy petroleum feedstocks, for example heavy oils of the Urals brand, which includes the separation of solid additives from unconverted hydrocracking residues with their subsequent drying and allows to obtain from the residues formed during such processing, popular products (sintering additive, bitumen products, etc.) and spent additive with asphaltenes and metals adsorbed on it in the form of porphyrin complexes, which can then be used in the form of solid fuel for combustion, extraction of metals or production of charge for metallurgical industry.

SUMMARY OF THE INVENTION

The present invention is directed to solving at least some of the problems mentioned above.

In accordance with the first aspect of the present invention, there is proposed a unit for separating spent additives from an unconverted hydrocracking residue of a heavy petroleum feedstock, including three successively located sections, each of which includes a mixing tank, a pump and a separating tank, wherein the mixing tank of the first section is configured to mixing a suspension flow containing a coal additive and an unconverted hydrocracking residue of heavy petroleum feedstock with a solvent, as well as with a recycle flow from the separation tank of the first section and with a recycle flow from the separation tank of the second section to reduce the viscosity and concentration of the suspension, the pump is designed to supply suspension mixture from the mixing tank into the hydrocyclone in the separation tank, which is configured to separate the suspension mixture and direct the upper flow from the hydrocyclone partially back to the mixing tank of the first section and partially to the buffer tank of the solvent regeneration unit and fractionation of purified petroleum products, as well as directing the lower flow from hydrocyclone into the internal space of the separation tank, from where it is directed to the mixing tank of the second section, the mixing tank of the second section is configured to mix the flow from the separation tank of the first section with the recycle flow from the separation tank of the third section, the pump of the second section is configured to supply a suspension mixture from the mixing tank reservoir of the second section into a hydrocyclone installed in the separation tank of the second section and configured to separate the suspension mixture and direct the upper flow from the hydrocyclone back to the mixing tank of the first section, as well as direct the lower flow from the hydrocyclone into the internal space of the separation tank, from where it is directed to the mixing tank the tank of the third section, the mixing tank of the third section is configured to mix the flow from the separation tank of the second section with the solvent from the solvent regeneration unit and fractionation of purified petroleum products, the pump of the third section is configured to supply a suspension mixture from the mixing tank of the third section to a hydrocyclone installed in the separation tank the third section and configured to separate the suspension mixture and direct the upper flow from the hydrocyclone into the mixing tank of the second section, as well as direct the lower flow from the hydrocyclone into the internal space of the separation tank, from where it is directed to the drum dryer of the spent additive drying unit, with the upper flow from each the hydrocyclone includes a mixture of unconverted residue and solvent, and the bottom stream from each hydrocyclone includes wet spent carbon additive.

According to one embodiment of the spent additive separation unit, the upper fitting of the hydrocyclone is connected directly to the upper fitting of the separation tank.

According to another embodiment of the spent additive recovery unit, the solvent is aromatic light gas oil from catalytic cracking and/or regenerated solvent from the solvent regeneration and fractionation unit for refined petroleum products.

According to another embodiment of the spent additive separation unit, a gas cushion is provided at the top of the separation tank to control the level of fluid in the tank and regulate the drainage from the tank.

According to another embodiment of the spent additive separation unit, the solvent supply pipeline and the recycle flow supply pipelines from the separation tank of the first section and the separation tank of the second section are connected to the supply pipeline of the suspension flow containing the coal additive and the unconverted hydrocracking residue of heavy oil feedstock, to the mixing tank of the first section, implementing preliminary mixing of streams.

According to another embodiment of the spent additive separation unit, the mixing tank includes a system of two valves, one of which is configured to supply natural gas to the tank, and the second is configured to release excess pressure to regulate the pressure in the tank.

According to another embodiment of the waste additive separation unit, the flow of the bottom flow from the separation tank to the mixing tank is controlled by a valve.

According to another embodiment of the spent additive separation unit, in the pipeline sections from the separation tanks to the mixing tanks, the valves are mounted at a minimum distance under the separation tanks.

According to another embodiment of the spent additive separation unit, two pneumatic vibrators are installed on the valve assemblies under the separation tanks, with one pneumatic vibrator installed before the valve, and the second installed after the valve.

According to another embodiment of the spent additive separation unit, the mixing tank of the second section is configured to mix the flow from the separation tank of the first section with the recycle flow from the separation tank of the third section and with the flow from the hydrocyclone unit of the solvent regeneration unit and fractionation of purified petroleum products.

According to another embodiment of the spent additive separation unit, the mixing tank of the third section is configured to mix the flow from the separation tank of the second section with the solvent from the solvent regeneration unit and fractionation of purified petroleum products and with the flow from the hydrocyclone unit of the solvent regeneration unit and fractionation of purified petroleum products.

In accordance with the second aspect of the present invention, there is proposed a drying unit for spent coal additive, separated from a suspension of coal additive and unconverted hydrocracking residue of heavy petroleum feedstock, including a drum dryer, a drum cooler and a crusher, wherein the drum dryer is configured to evaporate liquid hydrocarbons, including solvent , from wet spent coal additive received from the spent additive separation unit, and feeding them after condensation into the buffer tank of the solvent regeneration unit and fractionation of refined petroleum products, as well as unloading particles of dry spent additive into a drum cooler, designed with the ability to cool the spent coal additive for supply it into a crusher configured to grind the cooled spent coal additive, and in the exhaust gas line from the drum dryer, designed to remove gases from the drum dryer, including evaporated hydrocarbons and steam, a mechanical device is installed to remove dust-like particles of waste adhering to the wall. coal additive.

According to one embodiment of the spent coal additive drying unit, the mechanical device is an electrically driven pusher.

According to another embodiment of the spent coal additive drying unit, the pusher is equipped with cutters.

According to another embodiment of the spent coal additive drying unit, a condensate drain line is provided in the exhaust gas line and low pressure steam is supplied through a nozzle to the condensate drain line.

According to another embodiment of the spent coal additive drying unit, superheated steam is supplied to the exhaust gas line.

In accordance with the third aspect of the present invention, a unit for solvent regeneration and fractionation of refined petroleum products is proposed, which includes a buffer tank designed to store raw materials for feeding a vacuum column, a vacuum column raw material pump, a hydrocyclone unit for additional purification of the stream from particles of spent carbon additive, a heater and a vacuum column for separating the solvent and the heavy unconverted hydrocracking residue of heavy petroleum feedstock, wherein the buffer tank is configured to receive and accumulate a flow of a mixture of unconverted hydrocracking residue and solvent from the separation tank of the spent additive separation unit and the stream representing the condensate of hydrocarbon vapors discharged from the drum dryer unit for drying the spent additive, the raw material pump of the vacuum column is configured to supply raw materials from the buffer tank to a hydrocyclone unit, configured to clean the raw materials, and the hydrocyclone unit is configured to direct the bottom flow, including a suspension of particles of the spent coal additive, into the second mixing tank section and/or into the mixing tank of the third section of the spent additive separation unit, and the output of the upper flow of the hydrocyclone unit, including the purified product, for heating into the heater and then into the vacuum column, the vacuum column is configured to obtain a regenerated solvent to direct it to the unit separation of the spent additive and the bottoms of the vacuum column, which is an unconverted residue from the hydrocracking of heavy petroleum feedstock purified from the spent coal additive.

According to one embodiment of the solvent recovery and refined petroleum product fractionation unit, the hydrocyclone unit is a battery hydrocyclone unit including multiple hydrocyclones, each of which can be turned off or on to control the productivity and efficiency of the unit.

In accordance with the fourth aspect of the present invention, a system is proposed for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from spent coal additives, including a waste additive separation unit, a spent additive drying unit, a solvent regeneration unit and a fractionation unit for refined petroleum products.

In accordance with the fifth aspect of the present invention, a method is proposed for purifying unconverted hydrocracking residue of heavy petroleum feedstock from spent coal additive, performed by a system for purifying unconverted hydrocracking residue of heavy petroleum feedstock from spent coal additive, including the steps of: supplying a suspension to a spent additive separation unit , containing a coal additive and an unconverted residue from hydrocracking of heavy petroleum feedstock, and a solvent; the wet spent coal additive is removed from the spent additive separation unit into the spent additive drying unit; the solvent is evaporated from the wet spent coal additive in the spent additive drying unit, the dry spent coal additive is cooled and it is crushed; a mixture of unconverted hydrocracking residue and solvent is removed from the spent additive separation unit and solvent vapor condensate from the spent additive drying unit and supplied to the solvent regeneration unit and fractionation of purified petroleum products; a regenerated solvent is obtained in the unit for solvent regeneration and fractionation of purified petroleum products to send it to the unit for separating the spent additive and the purified unconverted residue from the hydrocracking of heavy petroleum feedstock.

In accordance with the sixth aspect of the present invention, a method for processing heavy petroleum feedstock is provided, which includes the steps of: hydrocracking the feedstock in a slurry phase (HSP), including the heavy petroleum feedstock and a coal additive, followed by separation into a stream of feedstock subjected to HSP, and a heavy residue stream, wherein the heavy residue stream is a suspension of unconverted high-boiling residue and spent coal additive; carry out hydrocracking of hydrocracking products of raw materials obtained at the GSF stage in the gas phase with a stationary catalyst bed, followed by fractionation of hydrocracking products; performing a method for purifying an unconverted hydrocracking residue of a heavy petroleum feedstock from a spent coal additive to obtain a spent coal additive and a purified unconverted hydrocracking residue of a heavy petroleum feedstock.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further explained by describing preferred embodiments of the invention with reference to the accompanying drawings, in which:

Fig. 1 is a flow diagram of a heavy petroleum feedstock processing process according to the present invention;

Fig. 2 schematically depicts a system for purifying unconverted hydrocracking residue from coal additive in accordance with the present invention;

Fig. 3 schematically shows a waste additive separation unit in accordance with the present invention;

Fig. 4 schematically shows a spent additive drying unit after a spent additive separation unit in accordance with the present invention;

Fig. 5 schematically shows a unit for solvent regeneration and fractionation of purified petroleum products in accordance with the present invention;

Fig. 6 is a sectional view of a thin film evaporator housing;

Fig. 7 is a general view of the feed distributor of a thin film evaporator;

Fig. 8 shows a general view of the rotor of a thin film evaporator with installed scrapers;

Fig. 9 shows a redistributor of raw materials.

DETAILED DESCRIPTION OF THE INVENTION

In fig. 1 is a flow diagram of a heavy petroleum feedstock processing process according to the present invention.

The feedstock for the heavy petroleum feedstock refining process, which is a suspension of heavy petroleum feedstock and a coal additive, which is usually added in an amount of 1 to 2% by weight of the heavy petroleum feedstock, is fed into the slurry phase hydrocracking reactor (SPH) at stage (1 ) GSF (see Fig. 1). As special cases of heavy oil feedstock, tar, products in the form of atmospheric column bottoms, vacuum column bottoms, heavy recirculating gas oil, shale oils, liquid fuels from coal, bottoms of crude oil, oils without light fractions and heavy bituminous oils can be considered.

At stage (1) HSF uses hydrogen-containing gas, in particular hydrogen, which is supplied to a pre-formed suspension of heavy petroleum feedstock, in particular tar, and a coal additive used for the adsorption of heavy hydrocarbons of the asphaltene series.

The additive in accordance with an exemplary embodiment contains a porous carbon material of two different particle size compositions - a coarse fraction and a fine fraction: a fine fraction with a diameter of particle sizes from 0.063 to 0.4 mm, a coarse fraction with a particle size from 0.4 to 1.2 mm . Taking into account the fact that the GSF process can be carried out in one or several reactors, the size of the additive depends on the productivity of the installation and the number of reactors in the first stage of GSF: the lower the productivity, the smaller the number and volume of reactors, the smaller the size of the additive. Carbon materials are known in the art that can be used to produce coal additives for combined hydrocracking. These are, for example, lignite, activated brown or long-flame coal. Activated carbons modified with metal salts (Fe, Mo, Ni and others) can also be used as carbon additives.

In this case, it is necessary that the activated carbon additive be characterized by the following porosity indicators:

Specific surface not less than 230 m ² /g;

The total pore volume according to BJH is not less than 0.25 cm ³ /g;

The volume of mesopores according to BJH is not less than 0.125 cm ³ /g.

At stage (1) of GSF, hydrocarbons are split and saturated in a hydrogen environment, while asphaltenes, and with them metals such as Ni, V, etc., which are catalytic poisons for gas-phase hydrocracking, are adsorbed on the coal additive.

About 95% of hydrocarbons are converted into a gaseous partially hydrogenated hydrocarbon mixture containing lighter hydrocarbon components, such as _C1 , _C2 , _C3 , _C4 , _C5 hydrocarbons, naphtha, diesel fraction and vacuum gas oil, as well as _H2S , NH ₃ , H ₂ O.

The remaining about 5% is a suspension consisting of the mentioned carbon additive with adsorbed asphaltenes and metals and an unconverted high-boiling residue, which is a mixture of predominantly high-boiling hydrocarbons with an initial boiling point above 525 ° C. The carbon additive after step (1), in which asphaltenes and metals have been adsorbed, will be referred to as “spent carbon additive” for the purposes of this patent.

The products obtained at stage (1) of GSF are separated at stage (2) of separation into gaseous products and a suspension of unconverted high-boiling residue and spent coal additive. The separation section is located between the GSF section and the gas-phase hydrocracking section.

Gaseous products are sent to stage (3) of hydrocracking in the gas phase with a stationary bed of catalyst, followed by fractionation of the resulting product stream to obtain light petroleum products. Vacuum gas oil (VGO) is also supplied to the same stage.

The suspension of the unconverted high-boiling residue and the spent coal additive enters the separation stage (4) into the system (10) for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from the spent coal additive.

It is preferable that the additive is characterized by a sufficiently high (more than 25% of the total pore volume) volume of mesopores, that is, pores whose size exceeds 10 nm, for more efficient adsorption of asphaltenes.

A developed specific surface area (at least 230 m ² /g), especially if it is provided by a large number of mesopores, additionally contributes to a large liquid-solid interface at which cracking reactions occur. In addition, on a more developed surface, it is easier for asphaltenes to enter the pores without the risk of “flying out” due to the complex geometry of the pores, that is, they act as a kind of pore “lock” for asphaltenes.

However, not all asphaltenes of the feedstock, as well as carbenes and carboids formed as a result of side compaction processes during hydrocracking, are adsorbed by the carbon additive. About 10 wt. % of these substances remain in the form of a dispersed phase surrounded by a dispersion medium, which leads to an imbalance between asphaltenes and, on the one hand, aromatic hydrocarbons that disperse asphaltenes, and, on the other hand, saturated hydrocarbons that contribute to the precipitation of asphaltenes. As a consequence, such an unconverted high-boiling residue is aggregatively unstable, which leads to its delamination and the appearance of difficult-to-control deposits in the form of asphaltene sediment. Such deposits negatively affect the operation of equipment, leading to wear, shutdowns and difficulties in cleaning and replacing deposit-prone equipment.

In this regard, it would be desirable to increase the content of aromatic hydrocarbons in the dispersion medium, thereby preventing the precipitation of those asphaltenes that were not adsorbed by the additive.

In addition, the unconverted high-boiling residue is a fairly viscous liquid, with the flow of which the spent coal additive along with asphaltenes and metals adsorbed on it can be entrained for further processing. Therefore, it is necessary to effectively reduce the viscosity of the unconverted high-boiling residue to separate the spent coal additive from it. Effective viscosity reduction in this case means the creation of a viscosity and density gradient between the unconverted residue and the spent carbon additive so that the created gradient facilitates the separation of the spent additive. Taking into account the above, in order to reduce the viscosity and at the same time prevent delamination, a solvent of an aromatic nature that does not contain paraffins - natural precipitants of asphaltenes - is suitable.

The above-mentioned problem of separating the spent coal additive from the unconverted hydrocracking residue of heavy petroleum feedstock in accordance with the present invention is solved in a system (10) for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from the spent coal additive, including a spent additive separation unit (40), in which stage (4) of separation of the unconverted hydrocracking residue and the spent additive is performed, a unit (50) for drying the spent additive, in which step (5) of drying the spent additive is performed, and a unit (60) for solvent regeneration and fractionation of refined petroleum products, in which step (6) is performed ) solvent regeneration and fractionation of unconverted hydrocracking residue.

Next, the system (10) for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from the spent coal additive will be described in more detail with reference to FIG. 2.

The process of separating the spent coal additive from the unconverted high-boiling residue occurs at the separation stage (4), at which the additive is washed with a solvent in the spent additive separation unit (40).

In general, the unit for separating spent additives from the unconverted hydrocracking residue of heavy petroleum feedstock includes several successively located sections, each of which includes a mixing tank, a pump and a separation tank.

The number of sections in the spent additive separation unit is selected depending on the desired productivity, the required efficiency of the spent additive separation and quality indicators of the initial suspension, and varies from 2 to 7.

The mixing tank of the first section is configured to mix a suspension flow containing a coal additive and unconverted hydrocracking residue of heavy petroleum feedstock with a solvent, as well as with a recycle flow from the separation tank of the first section and with a recycle flow from the separation tank of the subsequent section to reduce the viscosity and concentration of the suspension . The pump is configured to supply a suspension mixture from the mixing tank to the hydrocyclone in the separation tank, which is configured to separate the suspension mixture and direct the upper flow from the hydrocyclone partially back to the mixing tank of the first section and partially to the buffer tank of the solvent regeneration unit and fractionation of purified petroleum products, and also directing the bottom flow from the hydrocyclone into the internal space of the separation tank, from where it is directed to the mixing tank of the subsequent section with a similar operating principle. In this case, the upper flow from each hydrocyclone includes a mixture of unconverted residue with a solvent, and the lower flow from each hydrocyclone includes wet spent coal additive.

In the final section in the waste additive separation unit, the mixing tank is configured to mix the flow coming from the separation tank of the previous section with the solvent and, optionally, with the suspension flow coming from the battery hydrocyclone unit of the solvent regeneration unit and fractionation of purified petroleum products; the pump is configured to supplying the suspension mixture from the mixing tank to the hydrocyclone in the separation tank, which is configured to separate the suspension mixture and direct the upper flow from the hydrocyclone back to the mixing tank of the previous section, as well as directing the bottom flow from the hydrocyclone into the internal space of the separation tank, from where it is directed to the drum desiccant for waste additive drying unit.

If the waste additive separation unit includes at least three sections, then each of the middle (intermediate) sections also includes a mixing tank, a pump and a separation tank, and the mixing tank of this section is configured to mix the flow coming from the separation tank of the previous one. section, with a recycle flow from the separation tank of the subsequent section and, optionally, with a suspension flow coming from the battery hydrocyclone installation of the solvent regeneration unit and fractionation of refined petroleum products, the pump is configured to supply the suspension mixture from the mixing tank to the hydrocyclone in the separation tank, which is made with the possibility of separating the suspension mixture and directing the upper flow from the hydrocyclone back to the mixing tank of the previous section, as well as directing the lower flow from the hydrocyclone into the internal space of the separation tank, from where it is directed to the mixing tank of a subsequent identical intermediate section or final section.

As a solvent, a “fresh” solvent is supplied to the spent additive separation unit from outside the system (10) for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from the spent coal additive and a regenerated solvent from the solvent regeneration unit and fractionation of refined petroleum products.

In the preferred embodiment of the present invention discussed herein, the waste additive recovery unit (40) (see FIG. 3) includes three sections, each consisting of a mixing tank, a pump and a separating tank.

In the mixing tank (401) of the first section, using a stirrer, the flow of a suspension of coal additive and the unconverted hydrocracking residue of heavy petroleum feedstock, having a temperature of 310-420 ° C, a pressure of 1.05-1.15 MPa (g) and a flow rate of 18- 33 t/h, with a solvent flow having a flow rate of 7-10 t/h, a temperature of 250-260 ° C and a pressure of 0.8-1.0 MPa (g), a recycle stream of the liquid phase containing the solvent from the separation tank (403) of the first section, having a flow rate of 5-15 t/h, a temperature of 280-300 ° C and a pressure of about 0.36-0.46 MPa (g), and a recycle flow of the liquid phase containing the solvent from the separation tank ( 406) of the second section, having a flow rate of 50-70 t/h, a temperature of 250-270°C and a pressure of 0.28-0.35 MPa (g). Thus, connected to the input of the mixing tank (401) of the first section is a supply pipeline for the flow of a suspension of coal additives and unconverted hydrocracking residue of heavy petroleum feedstock, a solvent supply pipeline, the upper outlet of the separation tank (403) of the first section and the upper outlet of the separation tank (406) of the second section . The solvent supplied to the mixing tank (401) of the first section is "fresh" solvent from outside the system (10) for purifying unconverted heavy petroleum hydrocracking residue from spent coal additive (for example, after step (8) described below) and /or regenerated solvent from the vacuum column (605) of the unit (60) for solvent regeneration and fractionation of refined petroleum products. The addition of a solvent makes it possible to reduce the viscosity and density of the suspension in the first section, which increases the efficiency of further separation of the spent coal additive from the mixture of the unconverted high-boiling residue with the solvent. The solvent supply line and the recycle stream supply lines from the separation tank of the first section and the separation tank of the second section are connected to the supply line of the slurry stream of the coal additive and the unconverted hydrocracking residue of the heavy petroleum feedstock to the mixing tank of the first section so that the solvent and recycle stream are added to said slurry stream in the pipeline to the mixing tank (401), realizing preliminary mixing of the flows. Optionally, solvent and/or recycle streams may be supplied directly to the mixing tank (401). The mixing tank (401) of the first section in the preferred embodiment is a vertical cylindrical apparatus with a conical bottom. A cushion of fuel gas is provided at the top of the mixing tank (401) to regulate the pressure level in the tank to reduce evaporation of valuable solvent. At the same time, a temperature of 300-310°C and a pressure of 0.21-0.22 MPa (g) are maintained in the reservoir (401). From the upper part of the mixing tank (401), the released low-pressure hydrocarbon gases are freely directed through drainage tanks to the flare. The outlet of the mixing tank (401) is connected to the inlet of the hydrocyclone in the separation tank (403) of the first section, and a pump (402) is installed between the outlet of the mixing tank (401) and the inlet of the said hydrocyclone. The suspension mixture, having a temperature of 280-300˚C and a pressure of 0.8-1.1 MPa (g), is supplied from the mixing tank (401) by a pump (402) to the hydrocyclone installed in the separation tank (403) of the first section. Optionally, a portion of the slurry mixture can be pumped (402) back into the mixing tank (401) to provide better mixing due to this circulation.

In the separation tank (403), which is a vertical cylindrical apparatus with a conical bottom, due to the operation of the hydrocyclone, the spent coal additive is separated from the mixture of the unconverted high-boiling residue with the solvent. A gas cushion is provided at the top of the separation tank (403) to control the level of fluid in the tank and to regulate drainage from the tank. Increasing the gas cushion pressure, if necessary, allows the spent coal additive to be pushed further downstream, thus reducing the risk of equipment clogging.

A hydrocyclone generally consists of a short cylindrical (upper) part with a pipe for tangential input of pulp (tangential to the surface of the cylinder) and a conical (lower) part with a hole at the top of the cone for unloading solid fractions.

The tangential input of the initial pulp and the axial unloading of the separation products lead to rotation of the pulp, its axial and radial movement from the walls of the apparatus to the drain and unloading holes. The rotating flow in a hydrocyclone has several zones: external (wall) - downward; internal – ascending; middle – circulation, occupying the main volume of the hydrocyclone. Heavier and larger solid particles arriving with the original pulp are thrown by centrifugal force onto the inner surface of the cylinder and are carried down by the rotating downward flow. Under the influence of the radial component of the flow (from the walls to the center) and the turbulent nature of its movement, light and small grains are carried into the inner zone. Part of the downward wall vortex flow in the lower zone of the cone turns upward, forming a drain. The hydrocyclone does not contain moving elements, which increases its reliability, while ensuring high efficiency in separating heavier and lighter fractions.

The upper connection of the hydrocyclone for removing the purified stream in the present solution is connected directly to the upper connection of the separation tank (403), due to which the upper and lower streams of the hydrocyclone do not mix with each other inside the tank (403), thereby increasing the separation efficiency.

The separation tank (403) of the first section is placed directly above the mixing tank (404) of the second section to allow the underflow of the separation tank (403) to gravity flow into the mixing tank (404) of the second section. Moreover, to reduce the likelihood of clogging the pipeline with asphaltene deposits, the mixing tank (404) of the second section is located at the minimum possible distance from the separation tank (403) of the first section.

The upper outlet of the separation tank (403) is connected to the input of the mixing tank (401) of the first section for supplying a recycle stream containing solvent and unconverted residue, and to the input of the buffer tank (601) of the solvent regeneration and fractionation unit (60) of refined petroleum products. The lower outlet of the separation tank (403) is connected to the input of the mixing tank (404) of the second section. The suspension mixture from the pump (402), entering the separation tank (403), is separated in a hydrocyclone into an upper light and lower heavier flow. The upper light stream, comprising a predominantly liquid phase containing solvent and unconverted residue, is partially sent back to the mixing tank (401) of the first section at a flow rate of 5-15 t/h and partially sent to the buffer tank (601) of the regeneration unit (60). solvent and fractionation of purified petroleum products with a flow rate of 40-60 t/h and a pressure of 0.36-0.45 MPa (g) for subsequent regeneration of the solvent without entering the internal space of the separation tank (403) due to the direct connection of the upper outlet of the hydrocyclone with the upper outlet of the separation tank (403).

From the buffer reservoir (601), the stream of unconverted residue and solvent is supplied by pumps (602) to a battery hydrocyclone unit (603) for additional purification, then the purified stream is fed to a vacuum column (605) to separate the solvent and heavy unconverted residue. The separated solvent is recycled back to the waste additive recovery unit (40) (for example, to the mixing tank (401) of the first section and/or mixing tank (407) of the third section). This process will be described in more detail below when describing the unit (60) for solvent regeneration and fractionation of purified petroleum products.

The lower, heavier flow from the hydrocyclone, which includes predominantly a wet solid phase containing spent coal additive, is drained into the internal space of the separation tank (403) and is then directed by gravity to the mixing tank (404) of the second section with a flow rate of about 35-45 t/h . The flow of the bottom heavy flow from the reservoir (403) to the reservoir (404) is controlled by valves.

The pressure difference between the upper and lower outlets of the hydrocyclone in the tank (403) should be maintained in the range of 0.04-0.07 MPa. The pressure in the separation tank (403) should be maintained in the range of 0.3-0.4 MPa (g), and the temperature should be maintained at 285-295°C. This ensures that the driving force for squeezing the suspension out of the separation tank is maintained. It is necessary to maintain excess pressure in the mixing tank to avoid boiling of the light fractions of hydrocarbons present in the solvent, which is ensured by a system of two valves, one of which is designed to supply natural gas to the tank, and the second is designed to relieve excess pressure. In this case, the operating pressure in the mixing tank should not exceed the pressure in the separation tank of the previous section in order to avoid breakthrough of the gas cushion from the mixing tank into the separation tank along the drain riser, which can lead to disruption of the operation of hydrocyclones installed inside the separation tanks.

Preferably, in the present invention, an aromatic light gas oil from a petroleum refining and petrochemical process is used as a solvent to increase the aromatic hydrocarbon content, in particular catalytic cracking, due to the aromatic hydrocarbon content exceeding 80% by weight. with the number of carbon atoms from 8 to 16. In a preferred embodiment of the present invention, said solvent circulates from the solvent regeneration and fractionation unit (60) of purified petroleum products to the waste additive separation unit (40). During normal operation, the solvent consumption is maintained at a constant level, while provision is made for the supply of a make-up amount of solvent from outside the system (10) to compensate for process losses.

This solvent allows you to effectively reduce the viscosity and density of the unconverted high-boiling residue and eliminate the precipitation of asphaltenes, since it increases the proportion of aromatics in the disperse system and does not contain paraffins, which are natural precipitants for asphaltenes, which avoids equipment clogging. Thus, the group composition provided in an aromatic light gas oil, where more than 80 wt.% aromatic hydrocarbons are present, provides better separation of the carbon additive from the unconverted high-boiling residue.

This provides the additional advantage that if the product obtained from said residue purified from spent carbon additive is used as a sintering aid for carbon products, the ash content of such sintering aid will be substantially reduced.

Light aromatic gas oil obtained during oil refining is usually used to produce diesel fuels and, as a result, it is impractical and unprofitable to use it as a solvent. Therefore, in order to provide additional light aromatic gas oil, it is proposed to use a heavy vacuum gas oil produced by the process of the present invention, as will be described below. This additional amount can be used as a solvent in separation step (4), which will further increase the efficiency and reduce the resource intensity of the method according to the invention. Thus, the present invention provides an additional source of raw material for the production of light aromatic gas oil, at least a portion of which can be used as a solvent according to the present invention. From the further description of the method, the features of providing the specified source of raw materials will be clear.

It should be noted that the more efficiently the carbon additive adsorbs asphaltenes, the less asphaltenes remain in the unconverted high-boiling residue, and the less aromatic solvent is required in step (4) of separating the unconverted hydrocracking residue and the spent additive. And the more effectively the spent additive is separated from the unconverted high-boiling residue at separation stage (4), the more stable the unconverted high-boiling residue will be from the point of view of the petroleum dispersed system.

The input of the mixing tank (404) of the second section is connected to the lower output of the separation tank (403) of the first section, the upper output of the separation tank (409) of the third section and, optionally, connected to the output of the hydrocyclone unit (603) of the solvent regeneration and fractionation unit (60). petroleum products. The wet solids stream entering the second section mixing tank (404) from the first section separation tank (403) is mixed with a liquid phase recycle stream containing solvent and unconverted residue from the third section separation tank (409) and, optionally, the suspension coming from the battery hydrocyclone unit (603). The design of this mixing tank may be similar to the design of the mixing tank of the first section. Optionally, the mixing tank (404) can be equipped with a stirrer.

A cushion of fuel gas is provided at the top of the mixing tank (404) to regulate the pressure level in the tank. At the same time, a temperature of 260-270°C and a pressure of 0.195-0.205 MPa (g) are maintained in the reservoir (404). From the upper part of the mixing tank (404), the released low-pressure hydrocarbon gases are freely directed through drainage tanks to the flare. The output of the mixing tank (404) of the second section is connected to the input of the hydrocyclone in the separation tank (406) of the second section, and a pump (405) is installed between the output of the mixing tank (404) and the input of the said hydrocyclone. The suspension mixture, having a temperature of 250-270˚C and a pressure of 0.8-1.1 MPa (g), is supplied from the mixing tank (404) by a pump (405) to a hydrocyclone installed in the separation tank (406) of the second section. Optionally, a portion of the slurry mixture can be pumped (405) back into the mixing tank (404) to provide better mixing due to this circulation.

A gas cushion is provided at the top of the separation tank (406) to control the level of fluid in the tank and to regulate drainage from the tank. Increasing the gas cushion pressure, if necessary, allows the spent coal additive to be pushed further downstream, thus reducing the risk of equipment clogging.

The separation tank (406) of the second section is located directly above the mixing tank (407) of the third section to allow the underflow of the separation tank (406) to gravity flow into the mixing tank (407) of the third section. In this case, to reduce the likelihood of pipeline clogging with asphaltene deposits, the mixing tank (407) of the third section is located at the minimum possible distance from the separation tank (406) of the second section.

The upper outlet of the separation tank (406) is connected to the inlet of the mixing tank (401) of the first section to supply a recycle stream containing solvent and unconverted residue. The lower outlet of the separation tank (406) is connected to the input of the mixing tank (407) of the third section. The suspension mixture from the pump (405), entering the separation tank (406), is separated in the hydrocyclone into an upper light and lower heavier flow. The upper light flow, which includes predominantly the liquid phase, is directed back to the mixing tank (401) of the first section with a flow rate of 50-70 t/h and a pressure of 0.28-0.35 MPa (g), without entering the internal space of the separation tank (406) by directly connecting the upper outlet of the hydrocyclone with the upper outlet of the separation tank (406).

The lower, heavier flow from the hydrocyclone, which includes predominantly a wet solid phase, is drained into the internal space of the separation tank (406) and is then directed by gravity to the mixing tank (407) of the third section with a flow rate of about 35-45 t/h. The flow of the bottom heavy flow from the reservoir (406) to the reservoir (407) is controlled by valves installed in the pipeline.

The pressure difference between the upper and lower outlets of the hydrocyclone in the tank (406) should be maintained in the range of 0.04-0.07 MPa. The pressure in the separation tank (406) should be maintained in the range of 0.3-0.4 MPa(g).

The input of the mixing tank (407) of the third section is connected to the lower output of the separation tank (406) of the second section, the output of the vacuum column (605) of the solvent regeneration and fractionation unit (60) of refined petroleum products and, optionally, connected to the output of the hydrocyclone unit (603) of the unit ( 60) solvent regeneration and fractionation of purified petroleum products. The wet solids stream entering the mixing tank (407) of the third section from the separating tank (406) of the second section is mixed with the solvent from the solvent regeneration and refined petroleum fractionation unit (60) and, optionally, with the slurry stream coming from the battery hydrocyclone unit (603). The design of this mixing tank is similar to the design of the mixing tank of the first section. Optionally, the mixing tank (407) can be equipped with a stirrer.

A cushion of fuel gas is provided at the top of the mixing tank (407) to regulate the pressure level in the tank. At the same time, a temperature of 250-260°C and a pressure of 0.195-0.205 MPa (g) are maintained in the reservoir (404). From the upper part of the mixing tank (407), the released low-pressure hydrocarbon gases are freely directed through drainage tanks to the flare. The outlet of the mixing tank (407) is connected to the inlet of the hydrocyclone in the separation tank (409) of the third section, and a pump (408) is installed between the outlet of the mixing tank (407) and the inlet of the said hydrocyclone. The suspension mixture, having a temperature of 250-270˚C and a pressure of 0.8-1.1 MPa (g), is supplied from the mixing tank (407) by a pump (408) to a hydrocyclone installed in the separation tank (409) of the third section. Optionally, a portion of the slurry mixture can be pumped (408) back into the mixing tank (407) to provide better mixing due to this circulation.

The separation tank (409) is preferably located directly above the drum dryer (501) of the spent additive drying unit (50).

A gas cushion is provided in the separation tank (409) to control the level of fluid in the tank and control the drainage from the tank. Increasing the gas cushion pressure, if necessary, allows the spent coal additive to be pushed further downstream, thus reducing the risk of equipment clogging.

The upper outlet of the separation tank (409) is connected to the inlet of the mixing tank (404) of the second section to supply a recycle stream containing solvent and unconverted residue. The lower outlet of the separation tank (403) is connected to the input of the drum dryer (501) of the spent additive drying unit (50). The suspension mixture from the pump (408), entering the separation tank (409), is separated in the hydrocyclone into an upper light and lower heavier flow. The upper light flow, which includes predominantly the liquid phase, is directed back to the mixing tank (404) of the second section with a flow rate of 50-70 t/h and a pressure of 0.2-0.4 MPa (g), without entering the internal space of the separation tank due to direct connection of the upper outlet of the hydrocyclone with the upper outlet of the separation tank.

The lower, heavier flow from the hydrocyclone, which includes predominantly the wet solid phase, is drained into the internal space of the separation tank (409) and then directed by gravity to the drum dryer (501) of the spent additive drying unit (50) with a flow rate of about 5-15 t/h . The flow of the bottom heavy stream from the reservoir (409) to the drum dryer (501) is controlled by valves.

The pressure difference between the upper and lower outlets of the hydrocyclone in the tank (409) should be maintained in the range of 0.04-0.07 MPa. The pressure in the separation tank (409) should be maintained in the range of 0.25-0.27 MPa, and the temperature should be maintained at 220-260°C.

Thus, the unit (40) for separating the spent coal additive during operation includes several suspension circulation circuits at once, which significantly increases the efficiency of separating the spent coal additive from the mixture of unconverted high-boiling residue and solvent due to repeated passage of the suspension through these circulation circuits:

- small circulation circuit: 401 → 402 → 403 → 401;

- average circulation circuit: 401 → 402 → 403 → 404 → 405 → 406 → 401;

- large circulation circuit: 401 → 402 → 403 → 404 → 405 → 406 → 407 → 408 → 409 → 404 → 405 → 406 → 401.

To ensure efficient operation of hydrocyclones in separation tanks (403, 406, 409), the following conditions must be met:

- high consumption of pumped liquid;

- high pressure difference between the top and bottom of the hydrocyclone (the top pressure should be greater than the bottom pressure);

- low viscosity and density of the pumped liquid.

In order to eliminate the formation of stagnant zones in separation tanks (403, 406, 409), as well as in sections of pipelines from separation tanks to mixing tanks, valves at the lower base of separation tanks are mounted at the minimum possible distance from a technological point of view under the tanks, while minimizing lengths of pipeline sections between shut-off valves, control valves and tanks.

To prevent blockages and increase the efficiency of washing activated lignite, two pneumatic vibrators are installed on the valve assemblies under the separation tanks, one pneumatic vibrator is installed before the valve, the second is installed after the valve.

Each of the pumps (402, 405, 408) of the first to third sections can have a backup pump (402-1, 405-1, 408-1) connected in parallel. The presence of backup pumps allows you to increase the reliability of the entire installation and prevent clogging of equipment with deposits due to the failure of any of the pumps.

Thus, the spent additive separation unit (40) allows for effective separation of the spent coal additive and a mixture of unconverted residue and solvent, and at the same time ensures stable operation of the equipment with a given performance and prevents clogging of the equipment with deposits, which avoids long-term equipment downtime and labor-intensive work on cleaning equipment from deposits.

The number of sections in the unit (40) can be increased or decreased to the required quantity, based on the quality indicators of the initial suspension: the higher the viscosity of the initial suspension, the higher the content of spent coal additive in it, and also the smaller the size of this spent coal additive and the higher the content of asphaltenes, carbenes and carboids, the greater the number of sections can be.

The spent additive drying unit (50) in accordance with the present invention includes a drum dryer (501), a valve (502), a drum cooler (503), a crusher (504), a solids storage (505) (see Fig. 4) .

Preferably, the drum dryer (501), valve (502), drum cooler (503) and crusher (504) are arranged vertically above each other. In this case, solid particles move between the mentioned blocks due to gravitational forces.

The drum dryer (501) consists of a drum vessel equipped with an externally heated chamber. During the drying process, wet residue may stick to the walls of the drum dryer. To prevent significant amounts of residue from sticking to the walls, the drum dryer is provided with an internal mechanical device that removes the sticky wet residue during rotation, such as a scraper. The drum dryer itself is located at a slight slope to the horizontal plane to reduce the residence time of the dried waste additive in the internal zone of the dryer in order to avoid cracking and coking. In addition, the residence time of the suspension in the drum dryer is controlled by the speed of rotation of the scraper or similar internal device. The drum dryer is heated by burning a fuel (such as gas) in an outer chamber.

In the drum dryer (501), the remaining solvent in the solid phase is removed by indirectly heating the wet solid additive to a temperature of 460-560°C with fuel gases coming from the burner and feeding superheated low-pressure steam into the dryer, preheated to a temperature of 450-540°C C due to the heat of exhaust flue gases from drum dryers.

The supplied superheated low-pressure steam reduces the partial pressure of hydrocarbons in the drum and also prevents the formation of dust, while the evaporation of the solvent in the spent additive occurs at lower temperatures.

Transportation and removal of residual hydrocarbons from the solid phase is carried out by changing the rotation speed of the dryers while maintaining a given temperature inside the drum. In operating mode, the drum dryer operates at a speed of 1-4 rpm.

In operating mode, the drum dryer is approximately 10-15% filled with raw material. In emergency situations, when the maximum filling of the drum dryer is more than 50%, its speed is increased to the maximum allowed parameter (10 rpm) to increase the speed of unloading pitch coke.

Exhaust gases generated during drying of the spent additive in a drum dryer, containing evaporated hydrocarbons, including solvent, and steam and having a temperature of 350-500˚C and a pressure of minus 1 - 5 kPa, are discharged from the drum dryer (501) into a Venturi mixer, where mixed with a hydrocarbon mixture (solvent) supplied by a pump at a temperature of no more than 200˚C, and in a Venturi mixer the solvent is sprayed through nozzles to capture entrained coal dust particles, some of the vapor is saturated with the solvent and condenses. The exhaust stream from the Venturi nozzle with a temperature of no more than 240°C is supplied to the air cooler, where it is cooled to a range of 40-85°C. The resulting stream then enters the dryer exhaust gas condensation tank, in which it is separated into vapor and an aqueous phase, sent for disposal, as well as hydrocarbons.

The resulting liquid hydrocarbons are pumped back to the Venturi mixer. Part of the liquid hydrocarbons is sent to the buffer tank (601) of the solvent regeneration unit and fractionation of purified petroleum products.

Due to the large amount of hydrocarbon vapors generated, with an increase in the supply of drying suspension to the drum dryer, the speed of the exhaust gases, trapping fine dust, increases. Subsequently, partial condensation of the dust and gas flow occurs, sticking to the inner wall of the pipeline, which in turn leads to a narrowing of the throughput of the exhaust gas pipeline, and the gas pressure in the drum dryer begins to increase, which can lead to its failure.

To solve this problem, in the first horizontal section of the exhaust gas line from the drum dryer, a mechanical device is installed inside the pipe, which prevents the pipe from clogging with small dust-like particles of the spent additive by removing deposits of particles of spent coal additive (coal dust) adhering to the wall. This reduces the risk of blocking the flue gas line.

Also, on the first horizontal section of the exhaust gas line, a condensate discharge line can be provided to a three-phase separator or to a special settling tank. In order to intensify the removal of condensate from the horizontal section of the exhaust gas line, low pressure steam (LP) is supplied through a nozzle to the condensate removal line.

In addition, to solve the problem of sticking of wet waste additive supplied to drum dryers to the walls of pipelines, superheated steam can be supplied instead of LP steam, which, due to its higher temperature, prevents an increase in viscosity and helps reduce the sticking of the suspension inside the pipeline. To swirl the flow in order to prevent condensation of the dust and gas flow and the deposition of fine dust, special devices can be installed to supply superheated steam at the outlet of exhaust gases from drum dryers.

In a drum dryer, the spent carbon additive mixed with a solvent is heated and held for some time. The residence time of the spent carbon additive in the drum dryer is set in such a way as to ensure complete evaporation of the solvent. The dryer is installed at a slight inclination (1-2.5°) and rotates slowly (1-4 rpm), which gradually moves solids through the dryer and removes them from the dryer.

The solids stream with hydrocarbon residues is discharged from the drum dryer (501) through a dual valve (502) and fed into the drum cooler (503), where the spent carbon additive is cooled. Optionally, it is possible to install chains inside the refrigerator and use steel balls in order to eliminate the risk of increasing particle size during the cooling procedure.

Next, the cooled spent coal additive enters the crusher (504), where it is crushed into small particles. The fine particles must be of such size and weight that these particles of spent coal additive are suitable for further pneumatic transportation. From the crusher, the spent coal additive enters the spent additive equalization hopper, in which a pressure of 0-1 kPa and a temperature of 15-85°C are maintained. From the equalization hopper, the spent additive is sent to receive the rotary feeder, and from the discharge of the rotary feeder, the spent additive is supplied to a closed pneumatic transportation system, through which it is sent to the storage (505) of solid particles, from where it can be unloaded as a marketable product into a shipping container.

Thus, the spent coal additive is removed from the process and can be used as a commercial product. The resulting spent coal additive can be used in the form of solid fuel for combustion, metal extraction or batch production for the metallurgical industry.

The spent additive drying unit (50), described above, allows for effective drying of the spent coal additive, and at the same time ensures stable operation of the equipment with a given performance and prevents clogging of the equipment, in particular, the exhaust gas line from the drum dryer, with small dust particles of the spent additive, which avoids long-term equipment downtime and labor-intensive equipment cleaning work.

Thus, after the unit (40) for separating the spent additive, the spent coal additive is removed from the process through the unit (50) for drying the spent additive, and the separated unconverted high-boiling residue mixed with a solvent enters the unit (60) for solvent regeneration and fractionation of refined petroleum products, where including the separation of the solvent from the isolated unconverted high-boiling residue.

The unit (60) for solvent regeneration and fractionation of purified petroleum products (see Fig. 5) includes a buffer tank (601) designed to create the necessary supply of raw materials to feed the vacuum column, a pump (602) for vacuum column raw materials, a hydrocyclone unit (603) for additional purification of the stream from particles of spent coal dust, a heater (604) and a vacuum column (605) for separation of the solvent and heavy unconverted residue.

The input of the buffer tank (601) is connected to the upper outlet of the separation tank (403) of the spent additive separation unit and to the output of the condensation tank of the exhaust gas of the dryer of the waste additive drying unit (50). The buffer tank (601) is supplied with a flow of oil emulsion of suspension raw materials from the separation tank (403) of the spent additive separation unit (40) and a flow of hydrocarbons, which is a condensate of gases removed from the drum dryer (501) of the spent additive drying unit (50). The buffer tank (601) maintains a pressure of 0.3-0.4 MPa.

The raw material from the buffer tank is supplied by the vacuum column raw material pump (602) to the hydrocyclone unit (603) for additional purification of the flow from smaller particles of spent coal additive. The hydrocyclone unit (603) is a battery hydrocyclone unit and includes several hydrocyclones, and depending on changes in the load (fluid flow), some of the cyclones can be turned off or turned on to regulate the performance of the unit (603). To prevent the product from solidifying inside the hydrocyclone unit, electrical heating is provided for the cyclones, the collector and the lower product pipeline. To prevent the product from solidifying, steam heating of the pipelines is provided in the product supply and return pipelines.

Instead of a hydrocyclone unit, another device (decanter, settling tank, filter) can be used, depending on the physicochemical properties (density, viscosity, asphaltenes content, coking) of the hydrocarbon stream, which must be separated from the additive using the invention.

The suspension separated in the hydrocyclone unit (603) enters the mixing tank (404) and/or the mixing tank (407) of the spent additive separation unit (40), and the purified product is mixed with the liquid flow from outside the unconverted residue purification system (10). hydrocracking of heavy oil feedstock from the spent coal additive (from the cold LP liquid phase separator) and is heated into the heater (604), where it is heated to a temperature of no more than 385˚C. The heated mixture enters the bottom part of the vacuum column (605) below the outlet bottom “blind” plate. Due to additional cleaning of the vacuum column feedstock using a hydrocyclone unit, the risk of clogging the furnace and vacuum column with deposits is significantly reduced.

The vacuum column is designed to reduce the boiling points of the substances involved in the process and has plates (contact devices) to ensure a minimum pressure drop. The vacuum column (605) is a packed column (two layers: top and bottom) with a pressure ranging from 10 to 100 mmHg, preferably from 10 to 70 mmHg, even more preferably from 10 up to 30 mmHg, in the upper part, equipped with a plate with a gas duct (“semi-blind” plate), which is the boundary of the upper section (vacuum gas oil layer) of the column with a nozzle, and a prefabricated (“blind”) plate, above which the lower packing layer, and below is the lower section, in which the main inlet to the column and the lower settling tank for the bottoms are located. The temperature of the vacuum column cube is maintained in the range of 250-260°C.

Vapors of hydrocarbon gases with a temperature of no more than 80 ºС from the top of the vacuum column (605) through the helmet pipe are directed for cooling into the intertubular space of the refrigerator (606) at the top of the vacuum column. Circulating cooling return water is used to cool the top of the vacuum column in the tube space of the refrigerator (606). Condensed vapors of hydrocarbon gases (reflux) enter the reflux tank (607) of the vacuum column. In the reflux tank (607) of the vacuum column, separation of oil product, acid water and waste gas occurs.

Vapors in the vacuum column (605) condense in the packing layer in the upper section, while the liquid, which is light VGO, is removed from the gas duct tray under the upper packing layer by a vacuum gas oil circulation pump (608) through a vacuum gas oil filter to remove solid particles and separated into four parts:

- the first part is cooled in the circulation cooler (609) of the vacuum column to a temperature of 40˚C and fed back to the zone above the upper layer of the vacuum column packing (605) for irrigating the column;

- the second part of the vacuum gas oil flow is returned directly to the bottom layer of packing in the vacuum column (605),

- the third part of the vacuum gas oil flow is directed from the vacuum column (605) through the filter bypass through the tube space of the VGO heating heat exchanger into the VGO raw material tank for further supply as raw material for gas-phase hydrocracking,

- a quarter of the vacuum gas oil flow after heating in the heat exchanger (610) to a temperature of 200-250˚C is supplied as a regenerated solvent to the spent additive separation unit (40).

Below the top section (vacuum gas oil layer) of the vacuum column (605) is another packing layer in which the vacuum gas oil is separated from the heavy vacuum gas oil. Heavy recycle vacuum gas oil is supplied through a pump (611) to a vacuum column (605) for internal circulation reflux. In this case, the balance quantity is removed by the pump beyond the boundary of the unit (60).

The lowest part of the vacuum column (605) is the bottom settling tank for the bottoms (heavy unconverted residue). The bottom residue is pumped by pump (612) of the bottom residue of the vacuum column beyond the boundary of the unit (60) for further production from it of a sintering additive, fuel oil, bitumen products, etc. In this case, the hot bottoms stream passes through the recuperative heat exchanger (610) of the dilution vacuum gas oil, where the light recycle gas oil is heated from the pump (608). A portion of the bottoms is fed to the very bottom of the vacuum column (605) for recirculation to mix the high-viscosity dark oil product.

Optionally, each of the pumps (602, 608, 611, 612) can have a backup pump connected in parallel (602-1, 608-1, 611-1, 612-1). The presence of backup pumps allows you to increase the reliability of the entire installation and prevent clogging of equipment with deposits due to the failure of any of the pumps.

In the exemplary embodiment depicted in FIG. 5, pumps (612, 612-1) of the vacuum column bottoms operate simultaneously, which allows increasing the linear flow rate of the vacuum column bottoms to a value of at least 1.5 m/s, which reduces the likelihood of sedimentation of remaining solid particles of the spent additive in the pipe and clogging of the equipment of the unit (60) for solvent regeneration and fractionation of purified petroleum products.

Thus, the products obtained in the solvent regeneration and fractionation unit (60) of refined petroleum products are:

- regenerated solvent separated during vacuum distillation - light vacuum gas oil (LVG);

- vacuum purified gas oil (VGO) and

- isolated heavy residue, which is a residual product of tar hydrocracking (RPHG).

The composition of the resulting OPGG is homogeneous, viscous, low-ash, with a fairly low sulfur content, due to the fact that it has undergone the hydrocracking stage, and the absence of benzpyrenes (unlike coal tar pitch), which is important for the environment. This combination of properties is ensured due to several factors:

1. the use of the residual product of the distillation of petroleum feedstock for the process of combined hydrocracking, which occurs in a hydrogen environment, which reduces the amount of sulfur and makes it possible to avoid benzopyrene in the products of this process, in particular in the residual products;

2. the use of a carbon additive with a high content of mesopores, which most effectively adsorbs asphaltenes of the raw material;

3. the use of a solvent in the system for purifying the unconverted hydrocracking residue from the coal additive, which makes it possible to achieve maximum removal of the spent additive from the unconverted high-boiling hydrocracking residue, which after the vacuum column enters the thin-film evaporator. Effective removal of spent additives from hydrocracking residues can significantly reduce the ash content of the concentrated hydrocracking residue.

The inventors hypothesized that the resulting residue has properties and composition that facilitate its use as a raw material for the production of a sintering additive for the production of metallurgical or foundry coke or electrode mass in the manufacture of carbon anodes, for example for the aluminum industry. Numerous experiments have confirmed this assumption.

In addition, the concentrated residue can be used to prepare petroleum coke or anode coke, for example, in a delayed coking unit.

It is preferable that the residue is concentrated in evaporators. It is known from the prior art that for the concentration of highly viscous media, for example, devices with natural circulation or devices in which the evaporation process is carried out from the film are used.

The best results are achieved using thin film evaporators.

The specified bottom residue (the separated heavy residue) is fed to the evaporation step (7) in a thin film evaporator (TFI) for concentration.

In this case, an important point for the quality of the sintering additive and distillate is the prevention of local overheating of the TPI, which leads to local coking of the film with the risk of the formation of larger volumes of coke deposits inside the apparatus. Such inclusions in the sintering additive that are susceptible to coking reduce its sintering properties, since a solid fraction of carbon remains in the coked material, which loses its sintering properties and which acts as ballast in the composition of the sintering additive.

As a result of numerous tests, devices in which the process takes place in a film created on the inner surface of a stationary body using a rotating rotor are considered to be the most effective for the production of sintering additives.

The main elements of these devices are a housing with a coaxially installed rotor and a distribution device. The film is created on the vertical surface of the housing using a rotor on which distribution scrapers are mounted.

To prevent this unfavorable effect, namely the formation of local coking, the design was improved as follows. The TPI was equipped with a double jacket, heated by flue gases, which are fed into the outer jacket and then distributed into the inner jacket. This feature is illustrated in FIG. 6. The presence of two jackets makes it possible to evenly distribute flue gases over the outer surface of the reactor vessel (RPV) and avoid local overheating.

All other things being equal, the higher the heating temperature of the raw material, the better the quality of the sintering additive in terms of “ring and ball softening temperature (R&B)”, but the lower its yield. The maximum temperature in the chamber is limited by the possibility of coke formation and the residence time of the mixture in the evaporator. Preferably the temperature is 400-450 °C.

The vacuum in the system can significantly reduce the temperature at which evaporation of light hydrocarbons begins and reduce the risk of coking of the released heavy residue. A decrease in pressure helps to reduce the content of volatile components in the sintering additive due to improved conditions for the evaporation of intermediate products (or resins of secondary origin). Preferably, the pressure is between minus 90 and minus 100 kPa

The residence time of the raw material in the apparatus is calculated based on the condition of the need to obtain a product with a residual mass fraction of volatile substances of no more than 60%, and preferably ranges from 20 to 30 s.

It is desirable that the process be carried out from a film whose thickness does not exceed 1.5 mm, most preferably does not exceed 1.2 mm, and is in the range of 1.1-1.15. Evaporation of a substance from a thin film of a specified thickness on the surface of the evaporator provides high rates of heat and mass transfer. In addition, film thickness has a direct impact on the quality of the resulting sintering additive, namely: less volatile substances, more sintering ability. In addition, a film of a given thickness for the claimed method reduces the risk of coking. With a larger film thickness, there is a risk of coking on the walls, and the scrapers may not be able to cope, and the rotor will jam. If the thickness is less than the specified one, then evaporation will occur too intensely, the residue will not have time to drain, which will also lead to local build-up, which in turn will lead to coking.

The feedstock (the separated heavy residue stream from the vacuum stripping column) is supplied to the top of the reactor by a distribution device as shown in FIG. 7, through discrete feed points evenly distributed along the diameter of the distribution device. This input ensures additional prevention of equipment coking over time and the elimination of coking inclusions in the resulting sintering additive.

Uniform distribution of raw materials along the height of the apparatus is ensured by the working elements (blades) of the rotor, distributed along the height of the rotor in the form of a spiral fragment, as shown in Fig. 8.

Along the height of the apparatus, flow redistributors are provided, which are metal plates in the shape of a circle, installed along the height of the reactor. The plates have grooves for scrapers. The purpose is to ensure uniform application of the raw material flow to the walls along the height of the reactor, excluding stagnant zones. This feature is illustrated in FIG. 9

To intensify the process, it may be possible to supply air oxygen to the lower part of the TPI at the rate of 40-50 l/hour, preferably 44-47 l/hour, even more preferably 45 l/hour, depending on the composition of the raw material, as well as the necessary quality requirements sintering additive. In this case, the process temperature can be reduced to 210-240°C.

The concentrated residue of hydrocracking of tar (COGG) is removed from the TPI cube. In some embodiments, the implementation provides for constant circulation of COGG in the TPI cube using a tangential input into the lower part of the TPI.

The upper product of TPI, distillate vapor, is removed from the reactor and condensed in the refrigerator. The condensed distillate is a heavy vacuum gas oil (HVOG), at least part of which is involved in the processing step (8) to increase the aromatic hydrocarbon content, in particular catalytic cracking, in order to obtain a solvent for a system for purifying the unconverted hydrocracking residue from the carbon additive.

At least part of the TVG is supplied to catalytic cracking in a mixture with one or more components: straight-run vacuum gas oil, hydrotreated vacuum gas oil from a combined hydrocracking unit and fuel oil. The ratio between these four catalytic cracker feed streams can vary over wide ranges, wt.%:

• Hydrotreated raw materials (hydrotreated vacuum gas oil from a combined hydrocracking unit and/or fuel oil from a gas condensate processing unit) - 10-80

• Non-hydrotreated raw materials (TVG and, optionally, straight-run vacuum gas oil) - 20-90

It should be taken into account that with an increase in the proportion of non-hydrotreated feedstock, the yield of light catalytic cracking gas oil increases. But to extend the life of the catalyst, non-hydrotreated feedstock should be diluted with hydrotreated feedstock. Also, the share of non-hydrotreated raw materials should not be increased, as this may lead to a deterioration in the quality of the main product - the catalysate, which is then used in the production of motor gasoline.

If fuel oil is used, then one should take into account the fact that for the purposes of catalytic cracking in the classical sense, straight-run fuel oil obtained by distillation from oil cannot be used. For catalytic cracking, fuel oil obtained from a gas condensate processing unit (GTU) is used, since in this case its properties are similar to vacuum gas oil obtained by distillation of oil, i.e. There are no heavy fractions (tar) in UPGK fuel oil.

The TPI bottom product is a concentrated hydrocracking residue that can be used as a sintering additive for the production of metallurgical coke.

The concentrated residue can also be subjected to further processing, for example, in a delayed coker, to produce petroleum coke or anode coke.

Thus, the present invention provides effective separation of the spent coal additive and a mixture of unconverted residue and solvent, stable operation of the system for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from the spent coal additive with a given productivity and prevents clogging of equipment with deposits, which avoids long-term equipment downtime and labor-intensive work for cleaning equipment from deposits.

In addition, the present invention makes it possible to achieve stable non-stop operation of the entire combined hydrocracking unit, obtain products with improved characteristics, consistently have a conversion of up to 95%, while ensuring the processing of residual hydrocracking products into popular products.

According to the present invention, the stability of operation of a combined hydrocracking unit considers continuous operation in established modes with a given productivity.

Example

Heavy oil feedstock, which is tar obtained after distilling lower-boiling fractions from Urals heavy oil and having an initial boiling point of 510°C and a density at 20°C of over 1000 kg/m ³ , is mixed with 1.5 wt.% ( per mass of tar) coal additives of two granulometric compositions: large - about 1 mm in diameter, fine - about 0.3 mm. Large and small fractions are characterized by different volumes of mesopores, and the volume of mesopores according to BJH for large and small fractions is at least 0.12 cm ³ /g for more efficient adsorption of asphaltenes, the molecular size of which ranges from 40 to 90 nm for tar from Urals oil . The coal additive has a BET specific surface area of about 250-280 m ² /g. Tar consumption is 185 t/h.

In the form of a suspension, the raw material is fed to the hydrocracking chamber, where hydrocracking occurs at a temperature of about 450°C and a pressure of about 20 MPa. A mixture of coal additive, tar and gas passes through three GSF reactors located in series. As a result, a mixture of gaseous products and a suspension is formed, consisting of a spent coal additive and an unconverted high-boiling residue. The specified mixture is sent to the separation stage, after which the gaseous stream is sent to gas-phase hydrocracking, and the suspension is sent to the unit (40) for separating the spent additive.

A suspension of unconverted high-boiling residue together with a solid spent additive, having a flow rate of about 20 t/h, a temperature of 320°C and a pressure of about 1.15 MPa (g), is fed into the mixing tank (401) of the first section. Before entering the first section into the mixing tank (401), a solvent stream having a flow rate of 7 t/h, a temperature of 250 ° C and a pressure of about 0.9 MPa (g), a recycle stream containing a solvent from the separation tank (403) of the first section, having a flow rate of 14 t/h, a temperature of 285 ° C and a pressure of about 0.45 MPa (g), and a recycle stream containing solvent from the separation tank (406) of the second section, having a flow rate of 58 t /h, temperature 260°C and pressure about 0.3 MPa (g). The mentioned streams are pre-mixed in the pipeline and then fed into the mixing tank (401) of the first section, in which mixing occurs using a mixer with a double mechanical seal, while a temperature of 306 ° C and a pressure of 0.22 MPa are maintained in the tank (401). hut). The pump (402) pumps the resulting mixture further with a flow rate of 100 t/h and a pressure of 0.9 MPa (g), and part of this mixture is supplied back to the mixing tank (401) of the first section to improve mixing due to such circulation, and part of the mixture fed into a hydrocyclone installed in the separation tank (403) of the first section. The pressure difference between the upper and lower outlets of the hydrocyclone is maintained at 0.05 MPa, while the pressure in the separation tank (403) is maintained at 0.35 MPa(g) and the temperature is maintained at 290°C. The upper light stream, which includes predominantly the liquid phase, is partially sent back to the mixing tank (401) of the first section with a flow rate of 14 t/h and partially sent to the buffer tank (601) of the solvent regeneration and fractionation unit (60) of refined petroleum products with a flow rate of 41 t/h and pressure 0.4 MPa (g). The lower, heavier flow from the hydrocyclone, which includes predominantly a wet solid phase, is drained into the internal space of the separation tank (403) and is then sent to the mixing tank (404) of the second section with a flow rate of about 45 t/h. The flow of the bottom heavy flow from the reservoir (403) to the reservoir (404) is controlled by valves.

The wet solids stream entering the mixing tank (404) of the second section from the separation tank (403) of the first section is mixed with the recycle liquid phase stream containing the solvent from the separation tank (409) of the third section and with the slurry flow coming from the battery hydrocyclone installations (603). Said liquid phase flow and slurry flow are supplied to the wet solid phase supply line before being introduced into the mixing tank (404) of the second section. The tank (404) is maintained at a temperature of 265°C and a pressure of 0.20 MPa. The pump (405) pumps the resulting mixture further with a flow rate of 100 t/h and a pressure of 0.9 MPa, and part of this mixture is fed back into the mixing tank (404) of the second section to improve mixing due to such circulation, and part of the mixture is fed into the hydrocyclone, installed in the separation tank (406) of the second section. The pressure difference between the upper and lower outlets of the hydrocyclone is maintained at 0.05 MPa, while the pressure in the separation tank (406) is maintained in the range of 0.35 MPa (g) and the temperature is maintained at 260°C. The upper light stream, comprising predominantly the liquid phase, is sent back to the mixing tank (401) of the first section at a flow rate of 58 t/h. The lower, heavier stream from the hydrocyclone, which includes predominantly the wet solid phase, is drained into the interior of the separation tank (406) and is then sent to the mixing tank (407) of the third section. The flow rate of the bottom heavy flow from the tank (406) to the tank (407) is about 35 t/h and is controlled by valves installed in the pipeline.

The wet solid phase flow entering the mixing tank (407) of the third section from the separation tank (406) of the second section is mixed with a solvent at a flow rate of 20 t/h from the solvent regeneration and fractionation unit (60) of refined petroleum products and with the suspension flow coming from the battery hydrocyclone unit (603). Said solvent stream and slurry stream are supplied to the wet solids supply line before being introduced into the mixing tank (407) of the third section. The reservoir (407) is maintained at a temperature of 255°C and a pressure of 0.20 MPa(g). The pump (408) pumps the resulting mixture further with a flow rate of 100 t/h and a pressure of 0.9 MPa, and part of this mixture is fed back into the mixing tank (407) of the third section to improve mixing due to such circulation, and part of the mixture is fed into the hydrocyclone, installed in the separation tank (409) of the third section. The pressure difference between the upper and lower outlets of the hydrocyclone is maintained at 0.05 MPa, while the pressure in the separation tank (409) is maintained at 0.26 MPa(g) and the temperature is maintained at 240°C. The upper light stream, comprising a predominantly liquid phase, is directed back to the mixing tank (404) of the second section. The lower, heavier flow from the hydrocyclone, which includes predominantly a wet solid phase, is drained into the internal space of the separation tank (409) and then directed by gravity to the drum dryer (501) of the spent additive drying unit (50) with a flow rate of 5 t/h. The flow of the bottom heavy stream from the reservoir (409) to the drum dryer (501) is controlled by valves.

An aromatic light catalytic cracking gas oil is used as the solvent in an exemplary embodiment of the present invention.

In the drum dryer (501), the wet solids are heated to 500°C to completely evaporate the liquid hydrocarbons, including the solvent. The drum dryer (501) is positioned at an angle of 2° and rotates slowly (about 2 rpm), thereby gradually moving solids through the dryer and removing them from the dryer. The flow of solid particles with hydrocarbon residues is discharged from the drum dryer (501) through a double valve (502) and fed into the drum cooler (503), where the spent coal additive is cooled to a temperature of no more than 60 °C. Next, the cooled spent coal additive enters the crusher (504), where it is crushed into small particles. Next, the spent coal additive is sent to the storage (505) of solid particles, from where it can be unloaded as a commercial product into a shipping container.

The solvent evaporated from the drum dryer is partially condensed and sent to the buffer tank (601) of the solvent regeneration unit and fractionation of purified petroleum products. In this case, in the exhaust gas line from the drum dryer, a mechanical device is installed inside the pipe, which prevents the pipe from clogging with small dust particles of the spent additive by removing deposits of spent coal additive particles adhering to the wall. In an exemplary embodiment, an electrically driven pusher is used as a mechanical device to remove coal dust deposits adhering to the wall, transfer it to a settling hopper, and release the internal section of the pipeline in the exhaust gas line. The pusher can be equipped with cutters to intensify the removal of coal dust deposits adhering to the wall.

After the unit (40) for separating the spent additive and the unit (50) for drying the spent additive, the spent coal additive is removed from the process, and the separated unconverted high-boiling residue mixed with aromatic light gas oil from catalytic cracking, further purified in a hydrocyclone unit (603), which includes several hydrocyclones, and heated in the heater (604) to a temperature of about 310°C, passes into the vacuum column. The vacuum in the upper part of the vacuum column is from 10 to 30 mmHg, the pressure difference between the bottom part of the vacuum column and the lower layer of the nozzle, including the “blind” plate, is no more than 15 mmHg, the temperature of the vacuum column bottom is about 255°C.

The products obtained during the vacuum distillation process are:

- regenerated solvent separated during vacuum distillation - light vacuum gas oil (LVG);

- vacuum purified gas oil (VGO) and

- isolated heavy residue, which is a residual product of tar hydrocracking (RPHG).

The solvent obtained during the vacuum distillation process is supplied to the inlet of the mixing tank (401) of the first section and/or to the inlet of the mixing tank (407) of the third section.

The isolated heavy residue (bottom residue) obtained by the above method has the following physical and mechanical properties:

Table 1

1 Density at 15 ᵒС, kg/m ³ 1.054 2 Flash point in an open crucible, ᵒС 195 3 Mass fraction of sulfur, % mass 1.945 4 Coking ability, wt% 21.21 5 Dynamic viscosity, cPa
At 200°C
At 240°C 221
45 6 Fractional composition, % mass Start of boiling, ⁰ C 340 Fraction 130-180 ⁰ C Fraction 180-200 ⁰ C Fraction 200-340 ⁰ C Fraction 340-460 22.98 Balance over 460 ⁰ WITH 77.02 Fraction 460-480 ⁰ C 7.60 Fraction 480-500 ⁰ C 7.60 Fraction 500-540 ⁰ C 14.80 Balance over 540 ⁰ WITH 47.02 7 Asphaltenes, wt.% 20.69 8 Carbenes, wt.% 1.01 9 Carboids, wt.% 2.27 10 Pour point, ᵒС plus 30

The specified bottoms (recovered heavy residue) for concentration are fed through a manifold with discrete feed points to a thin film evaporator (TFI).

The temperature in the reactor is maintained at 400 °C. The pressure in the reactor is maintained at minus 95 kPa.

The film thickness is 1.12 mm and is constant throughout the height of the apparatus.

The residence time of the raw material in the apparatus for the above-mentioned bottom residue and a given film thickness is set to 20 s.

Using the process of the present invention, a distillate was obtained having the following characteristics:

table 2

No.
p/p Indicator name Test method Test results
(average data) 1 Density at 20 ⁰С, kg/cm ³ GOST 3900 982.1 2 Mass fraction of sulfur, % GOST R 51947 1.93 3 Coking ability, wt% EN ISO 10370 1.55 4 Fractional composition: - initial boiling point, °C ASTM D 86 302 - distilled off at a temperature of 400°C, % 37 5 Kinematic viscosity at 50 °C, mm ² /s GOST 33 56.12 6 Pour point, °C GOST 20287 (method B) 23.4 7 Flash point in a closed crucible, ⁰С ASTM D 93 175.4 8 Asphaltenes content, mg/kg Total 642 710.6 9 Metal content Sodium, mg/kg ASTM D 5863 1.02 Iron, mg/kg 20.32 Nickel, mg/kg 2.51 Vanadium, mg/kg 1.05

The concentrated tar hydrocracking residue produced by the proposed method has the characteristics shown in Table 3:

Table 3

Name of determined indicators Unit measurements Test results ND for test method Ash content, dry state, A ^d % 0.6 GOST 22692-77 Mass fraction of volatile substances, dry state, V ^d % 52.4 GOST 22898-78 Mass fraction of total sulfur, dry state, S _t ^d % 2.23 GOST 32465-2013 Mass fraction of total carbon, dry state, Сd % 87.3 GOST 32979-2014 Mass fraction of water, W % 0.1 GOST 2477-2014 Mass fraction of insoluble substances in toluene, α % 25 GOST 7847-2020 Mass fraction of substances insoluble in quinoline, α ₁ % 5 GOST 10200-2017 Softening (melting) temperature KiS, T °C 113 GOST 9950-2020 Softening (melting) temperature KiSh, T °C 128 GOST 11506-1973 Softening (melting) temperature according to Metler, T °C 131 GOST 32276-2013 Gray-King coke type type G ₁₃ GOST 16126-91 (ISO502-82) Sintering index, G (1:5) units 80 GOST ISO 15585-2013 Sintering index, G (1:7) units 68 GOST ISO 15585-2013

These parameters make it possible to use COGG as a sintering additive to produce metallurgical coke, foundry coke or anodes for the aluminum industry, which have excellent sintering properties similar to the sintering properties of coal tar pitches.

Industrial tests of the claimed method demonstrate the possibility of achieving productivity for raw materials, in particular for tar, of at least 2,600,000 tons per year.

Claims (41)

1. Unit (40) for separating the spent additive from the unconverted hydrocracking residue of heavy petroleum feedstock, which includes three sections, each of which includes a mixing tank (401, 404, 407), a pump (402, 402-1, 405, 405 -1, 408, 408-1) and a separation tank (403, 406, 409), and The mixing tank (401) of the first section is configured to mix a suspension stream containing a coal additive and unconverted hydrocracking residue of heavy petroleum feedstock with a solvent, as well as with a recycle stream from the separation tank (403) of the first section and with a recycle stream from the separation tank (406 ) of the second section to reduce the viscosity and concentration of the suspension, the pump (402) is configured to supply the suspension mixture from the mixing tank (401) to the hydrocyclone in the separation tank (403), which is configured to separate the suspension mixture and direct the upper flow from the hydrocyclone partially back into the mixing tank (401) of the first section and partially into the buffer tank (601) of the unit (60) for solvent regeneration and fractionation of purified petroleum products, as well as directing the bottom flow from the hydrocyclone into the internal space of the separation tank (403), from where it is directed to the mixing tank ( 404) second section, the mixing tank (404) of the second section is configured to mix the flow from the separation tank (403) of the first section with the recycle flow from the separation tank (409) of the third section, the pump (405) of the second section is configured to supply a suspension mixture from the mixing tank (404) the second section into a hydrocyclone installed in the separation tank (406) of the second section and configured to separate the suspension mixture and direct the upper flow from the hydrocyclone back to the mixing tank (401) of the first section, as well as direct the lower flow from the hydrocyclone into the internal space of the separation tank ( 406), from where it is sent to the mixing tank (407) of the third section, the mixing tank (407) of the third section is configured to mix the flow from the separation tank (406) of the second section with the solvent, the pump (408) of the second section is configured to supply a suspension mixture from the mixing tank (407) of the third section to a hydrocyclone installed in the separation tank (409) of the third section and configured to separate the suspension mixture and direct the upper flow from the hydrocyclone into the mixing tank (404) of the second section, as well as direct the lower flow from the hydrocyclone into the interior of the separation tank (409), from where it is directed to the drum dryer of the unit (50) drying of the spent additive, wherein the top stream from each hydrocyclone includes a mixture of unconverted residue and solvent, and the bottom stream from each hydrocyclone includes wet spent carbon additive. 2. Unit (40) for separating the spent additive according to claim 1, in which the upper fitting of the hydrocyclone is connected directly to the upper fitting of the separation tank. 3. Unit (40) for separating the spent additive according to claim 1, in which the solvent is an aromatic light catalytic cracking gas oil and/or regenerated solvent from the unit (60) for solvent regeneration and fractionation of refined petroleum products. 4. The spent additive separation unit (40) according to claim 1, in which a gas cushion is provided in the upper part of the separation tank (403, 406, 409) to control the fluid level in the tank and regulate the drainage from the tank. 5. The spent additive separation unit (40) according to claim 1, in which the solvent supply pipeline and the recycle flow supply pipelines from the separation tank of the first section and the separation tank of the second section are connected to the supply pipeline of the suspension flow containing the coal additive and the unconverted heavy oil hydrocracking residue raw materials, to the mixing tank (401) of the first section, realizing preliminary mixing of the flows. 6. The spent additive separation unit (40) according to claim 1, in which the mixing tank (401, 404, 407) includes a system of two valves, one of which is configured to supply natural gas to the tank, and the second is configured to discharge overpressure, to regulate the pressure in the tank. 7. The spent additive separation unit (40) according to claim 1, in which the flow of the bottom flow from the separation tank to the mixing tank is controlled by a valve. 8. Unit (40) for separating the spent additive according to claim 7, in which in sections of pipelines from separation tanks to mixing tanks, valves are mounted at a minimum distance under the separation tanks. 9. Unit (40) for separating the spent additive according to claim 7, in which two pneumatic vibrators are installed on the valve assemblies under the separation tanks, with one pneumatic vibrator installed before the valve, and the second installed after the valve. 10. Unit (40) for separating the spent additive according to claim 1, in which the mixing tank (404) of the second section is configured to mix the flow from the separation tank (403) of the first section with the recycle flow from the separation tank (409) of the third section and with the flow from a hydrocyclone unit (603) of a unit (60) for solvent regeneration and fractionation of purified petroleum products. 11. Unit (40) for separating the spent additive according to claim 1, in which the mixing tank (407) of the third section is configured to mix the flow from the separation tank (406) of the second section with the solvent from the unit (60) for solvent regeneration and fractionation of refined petroleum products and with the flow from the hydrocyclone unit (603) of the unit (60) for solvent regeneration and fractionation of purified petroleum products. 12. Unit (50) for drying spent coal additive, separated from a suspension of coal additive and unconverted hydrocracking residue of heavy petroleum feedstock, including a drum dryer (501), a drum cooler (503) and a crusher (504), moreover The drum dryer (501) is configured to evaporate liquid hydrocarbons, including solvent, from the wet spent coal additive received from the spent additive separation unit (40), and supply them after condensation to the buffer tank (601) of the solvent regeneration and fractionation unit (60). purified petroleum products, as well as unloading particles of dry spent additive into a drum cooler (503), configured to cool the spent coal additive for feeding it into a crusher (504), configured to grind the cooled spent coal additive, Moreover, in the exhaust gas line from the drum dryer, designed to remove gases from the drum dryer, including evaporated hydrocarbons and steam, a mechanical device is installed to remove dust-like particles of the spent coal additive adhering to the wall. 13. Unit (50) for drying spent coal additive according to claim 12, in which the mechanical device is an electrically driven pusher. 14. Unit (50) for drying spent coal additive according to claim 13, in which the pusher is equipped with cutters. 15. Unit (50) for drying spent coal additive according to claim 12, in which a condensate drain line is provided in the exhaust gas line and low pressure steam is supplied through a nozzle to the condensate drain line. 16. Unit (50) for drying spent coal additive according to claim 12, in which the supply of superheated steam is provided in the exhaust gas line. 17. Unit (60) for solvent regeneration and fractionation of purified petroleum products, including a buffer tank (601) designed for storing raw materials to feed the vacuum column, a pump (602) for vacuum column raw materials, a hydrocyclone unit (603) for additional purification of the flow from particles spent coal additive, a heater (604) and a vacuum column (605) for separating the solvent and the heavy unconverted hydrocracking residue of the heavy petroleum feedstock, wherein The buffer tank (601) is configured to receive and accumulate a flow of a mixture of unconverted hydrocracking residue and solvent from the separation tank (403) of the spent additive separation unit and the flow, which is a condensate of hydrocarbon vapors discharged from the drum dryer (501) of the waste drying unit (50). additives, the pump (602) of the raw material of the vacuum column is configured to supply raw material from the buffer tank (601) to a hydrocyclone unit (603), configured to purify the raw material, and the hydrocyclone unit (603) is configured to direct the lower flow, including a suspension of waste particles coal additive, into the mixing tank (404) and/or into the mixing tank (407) of the unit (40) for separating the spent additive and discharging the upper flow of the hydrocyclone unit (603), including the purified product, for heating into the heater (604) and further into the vacuum column (605), the vacuum column is configured to produce a regenerated solvent to direct it to the unit (40) for separating the spent additive and the bottom residue of the vacuum column, which is an unconverted residue from the hydrocracking of heavy petroleum feedstock purified from the spent coal additive. 18. Unit (60) for solvent regeneration and fractionation of purified petroleum products according to claim 17, in which the hydrocyclone unit is a battery hydrocyclone unit, including several hydrocyclones, each of which can be turned off or on to regulate the unit's performance. 19. A system for purifying unconverted hydrocracking residue of heavy petroleum feedstock from spent coal additive, including: - unit (40) for separating the spent additive according to any one of claims. 1-11, - unit (50) for drying the spent additive according to any one of paragraphs. 12-16, - unit (60) for solvent regeneration and fractionation of purified petroleum products according to claim 17 or 18. 20. A method for purifying unconverted hydrocracking residue of heavy petroleum feedstock from spent coal additives, performed by the system according to claim 19, including the steps of: - a suspension containing a coal additive and an unconverted hydrocracking residue of heavy petroleum feedstock, and a solvent is supplied to the unit (40) for separating the spent additive; - the wet spent coal additive is removed from the spent additive separation unit (40) into the spent additive drying unit (50); - the solvent is evaporated from the wet spent coal additive in the unit (50) for drying the spent coal additive, the dry spent coal additive is cooled and it is crushed; - a mixture of unconverted hydrocracking residue and solvent is removed from the spent additive separation unit (40) and solvent vapor condensate from the spent additive drying unit (50) and supplied to the solvent regeneration unit (60) and fractionation of purified petroleum products; - in the unit (60) for solvent regeneration and fractionation of purified petroleum products, a regenerated solvent is obtained to send it to the unit (40) for separating the spent additive and the purified unconverted residue from the hydrocracking of heavy petroleum feedstock. 21. A method for processing heavy petroleum feedstock, including stages in which: - hydrocracking of raw materials is carried out in the suspension phase (HSF), including heavy oil raw materials and a coal additive, followed by separation into a stream of raw materials subjected to HSF, and a heavy residue stream, wherein the heavy residue stream is a suspension of unconverted high-boiling residue and spent coal additive; - hydrocracking of hydrocracking products of raw materials obtained at the GSF stage is carried out in the gas phase with a stationary layer of catalyst, followed by fractionation of the resulting hydrocracking products; - perform a method for purifying the unconverted hydrocracking residue of heavy petroleum feedstock from the spent coal additive according to claim 20 to obtain the spent coal additive and the purified unconverted hydrocracking residue of heavy petroleum feedstock.