EA024500B1 - Apparatus and process for hydroprocessing hydrocarbonaceous feedstock - Google Patents

Abstract

Two-stage hydroprocessing uses a common dividing wall fractionator. Hydroprocessed effluents from both stages of hydroprocessing are fed to opposite sides of the dividing wall.

Description

The invention relates to the hydrotreatment of hydrocarbons in two stages with conventional fractionation.

State of the art

Due to environmental problems, as well as in accordance with recently legalized rules and regulations, marketable petroleum products must have an increasingly lower limit for the content of pollutants such as sulfur and nitrogen. New regulations require the almost complete removal of sulfur from liquid hydrocarbons, which are used as part of transport fuels, such as gasoline and diesel fuel. For example, the requirements for diesel fuel with ultra-low sulfur content (L8I) are typically less than 10 parts per million sulfur.

Hydrotreating is a process in which the selected feedstock and hydrogen-containing gas are contacted with suitable catalyst (s) in the reaction vessel under conditions of elevated temperature and pressure. Typically, hydrogen is a separate phase in a three-phase system (gas / liquid / solid catalyst). Such hydroprocessing is usually carried out in an irrigated bed reactor in which the continuous phase is gaseous rather than liquid.

The continuous gas phase is in large excess from stoichiometry, which requires the extraction of gas, purification, compression and return back to the reaction vessel of hydroprocessing.

Hydrotreating in a continuous liquid phase with a liquid hydrocarbon stream and a solid catalyst has been proposed for converting certain hydrocarbon streams into more valuable hydrocarbon streams at lower hydrogen consumption. Hydroprocessing in the continuous liquid phase can be carried out without a recycle gas flow, since the hydrogen consumption can be slightly higher than stoichiometric.

Hydrotreating is a type of hydrotreatment, effective primarily in the removal of heteroatoms such as sulfur and nitrogen, and the formation of saturated compounds in hydrocarbon feedstocks. As a rule, hydrotreating can lead to an increase in the cetane number of hydrocarbon feedstocks and to the production of feedstock for further hydrotreatment.

Fractionation columns are necessary for separating the hydrotreated effluents into separate products with different boiling temperature ranges. Hydrotreated effluents typically produce naphtha, diesel, and heavier products.

Therefore, there is a continuing need for improved and cost-effective methods for producing hydrocarbon streams that meet increasingly stringent product requirements. In particular, there is a need for producing ILBI fuel in a cost-effective and efficient way without introducing an excess of heavier portions of product streams.

SUMMARY OF THE INVENTION

In an embodiment of the device, the present invention relates to a device for hydrotreating a hydrocarbon feed, including a first hydrotreatment reaction zone for hydrotreating a hydrocarbon feed. The separation wall fractionation column includes a separation wall extending to the bottom of the fractionation column with a separation wall that separates the fractionation column with the separation wall on the first side and the second side. The first side is connected with the first hydrotreatment reaction zone in front of it. The second hydrotreatment reaction zone is connected with the first side of the fractionation column with a dividing wall located in front of it along the flow. In the second hydrotreatment reaction zone, the diesel fuel stream is hydrotreated outgoing from the first side of the separation wall fractionation column. In addition, the second side of the fractionation column with a dividing wall is connected to the second hydrotreatment reaction zone located in front of it along the stream.

In a further embodiment of the device, the present invention relates to a device for producing low sulfur diesel fuel comprising a first hydrotreatment reaction zone for hydrotreating a hydrocarbon feed in order to reduce its sulfur concentration and increase its cetane number. The separation wall fractionation column includes a separation wall extending to the bottom of the column, which separates the fractionation column with the separation wall on the first side and the second side.

The first side is connected with the first hydrotreatment reaction zone in front of it. The second hydrotreatment reaction zone is connected with the first side of the dividing wall column upstream of it. In the second hydrotreatment reaction zone, the diesel feed stream is hydrotreated from the first side of the separation wall fractionation column. And finally, the second side of the fractionation column with a separation wall is connected to the second hydrotreatment reaction zone located in front of it along the stream.

In a further embodiment of the device, the present invention relates to a device for

- 1,024,500 production of diesel fuel with low sulfur content, which includes the first hydrotreatment reaction zone for hydrotreating hydrocarbon raw materials in order to reduce its sulfur concentration and increase its cetane number. The separation wall fractionation column includes a separation wall that separates the fractionation column with the separation wall on the first side and the second side. The first side is connected with the first hydrotreatment reaction zone in front of it. The second hydrotreatment reaction zone is connected with the first side of the dividing wall column upstream of it. In the second hydrotreatment reaction zone, the diesel feed stream is hydrotreated from the first side of the separation wall fractionation column. The second side of the fractionation column with a separation wall is connected to the second hydrotreatment reaction zone in front of it. And finally, the fractionation column is connected to the first side upstream of it and the second hydrotreatment reaction zone located upstream.

In an embodiment of the method, the present invention relates to a method for hydrotreating a hydrocarbon feedstock, comprising hydrotreating the hydrocarbon feedstock with hydrogen in a first hydrotreatment reaction zone with a hydrotreatment catalyst under conditions effective to produce a first hydrotreatment effluent. The first hydrotreated effluent is fractionated on the first side of the separation wall in the fractionation column with the separation wall to produce a diesel stream discharged from the bottom of the fractionation column with the separation wall. The diesel feed stream is hydrotreated with hydrogen in a second hydrotreatment reaction zone with a hydrotreatment catalyst to produce a second hydrotreated effluent. In conclusion, the second hydrotreated effluent is fractionated on the second side of the separation wall in the fractionation column with the separation wall to produce a hydrotreated diesel fuel stream. In one embodiment, the diesel feed stream is at least part of the diesel fuel stream.

In a further embodiment of the method, the present invention relates to a method for hydrotreating a hydrocarbon feedstock, comprising hydrotreating a hydrocarbon feed boiling in a boiling range of USO with hydrogen in a hydrotreatment reaction zone with a hydrotreating catalyst under conditions effective to produce a hydrotreated effluent having a lower sulfur concentration and a higher cetane number than the corresponding indicators of hydrocarbon feedstocks. The hydrotreated effluent is fractionated on the first side of the separation wall in the fractionation column with the separation wall to produce a diesel fuel stream. The diesel fuel stream is fractionated in a fractionation column to obtain a diesel feed stream. The diesel feed stream is hydrotreated with hydrogen in a hydrotreatment reaction zone with a hydrotreatment catalyst to produce a hydrotreated effluent. In conclusion, the hydrotreated effluent is fractionated on the second side of the separation wall in the fractionation column with the separation wall to produce a hydrotreated diesel fuel stream.

In a further embodiment of the method, the present invention relates to a method for producing low sulfur diesel fuel comprising hydrotreating a hydrocarbon feed with hydrogen in a first hydrotreating reaction zone with a hydrotreating catalyst under conditions effective to obtain a first hydrotreating effluent having a lower concentration sulfur and a higher cetane number than the corresponding indicators of hydrocarbon feedstocks. The first hydrotreated effluent is fractionated on the first side of the separation wall in the fractionation column with the separation wall to produce a diesel fuel stream. The diesel feed stream, which represents at least a portion of the diesel fuel stream, is hydrotreated with hydrogen in a second hydrotreatment reaction zone with a hydrotreatment catalyst to produce a second hydrotreated effluent. The second hydrotreated effluent is fractionated on the second side of the separation wall in the fractionation column with separation wall to produce an ultra low sulfur diesel stream.

Other embodiments of the invention include further details of the process, such as preferred sources of feed, preferred hydroprocessing catalysts, and preferred operating conditions, among others. Other similar embodiments and details are disclosed further herein in the following discussion of various aspects of the method.

Definitions

The term associated with means that the flow of materials in the operating mode is passed between the specified components.

The term “downstream” implies that at least a part of the substance entering the next component of the circuit downstream can exit during operation

- 2 024500 of the object with which it is associated.

The term located upstream means that at least a part of the substance entering the stream from the circuit component located upstream is able to enter the object with which it is connected.

The term column means a distillation column or columns to separate one or more components with different volatilities, which may have a boiler in the cube and a condenser in the upper part. Unless otherwise specified, each column includes a condenser in the upper part of the column for condensation and reflux as part of the overhead stream back to the upper part of the column, as well as a boiler in the column cube for evaporation and directing part of the bottoms product stream back to the bottom part of the column. The feed streams fed to the columns can be preheated. The pressure in the upper part is the absolute vapor pressure of the overhead at the outlet of the column. The bottom temperature is the outlet temperature of the liquid bottom product.

The implementation of the invention

The inventors have discovered a one-of-a-kind method and apparatus that utilizes a conventional fractionation zone between two hydroprocessing stages. The hydrotreated stream leaving the first hydrotreatment zone can be fed to the first side of the separation wall in the fractionation column with the separation wall. The diesel fuel stream from the first side of the dividing wall is either fed directly to the second hydrotreatment zone or fractionated in a fractionating column to remove hydrotreated UOF in order to feed the diesel stream into the second hydrotreatment zone. The second stream exiting the second hydrotreatment zone can be fed to the second side of the separation wall into a fractionation column with a separation wall to separate the U-IT fuel. which can be removed.

In one aspect, the devices and methods described herein are specifically applicable to hydrotreating hydrocarbon feedstocks containing diesel fuel or hydrocarbons boiling in the boiling range of the OO. Typical hydrocarbon feedstocks include hydrocarbon streams containing components boiling above 288 ° C (550 ° P), such as atmospheric gas oils, vacuum gas oils, deasphalted vacuum and atmospheric residues, hydrotreated or mild hydrocracked residual oils, coking distillates, straight distillates ; solvent deasphalted oils; pyrolysis oils, high boiling synthetic oils, recycle oils, catalytic cracking unit distillates and the like. Mentioned hydrocarbon sources of raw materials may contain from 0.1 to 4% sulfur.

A preferred hydrocarbon feed is a diesel stream or other hydrocarbon fraction containing at least 50 wt.%, And usually at least 75 wt.%, Of components boiling at temperatures above 149 ° C (300 ° P). A typical diesel fuel stream is typically characterized by a boiling range of 138 ° C (280 ° P) to 382 ° C (720 ° P).

Another preferred hydrocarbon feed is OO or another hydrocarbon fraction containing at least 50 wt.%, And usually at least 75 wt.%, Of components boiling at temperatures above 371 ° C (700 ° P). A typical vacuum gas oil is typically characterized by a boiling point range of 315 ° C (600 ° P) to 565 ° C (1050 ° P).

With reference to the drawing, a typical integrated hydrocarbon processing plant will be described in more detail. Specialists in the art should take into account that various design features of the method described above, such as pumps, control instruments, heat exchangers and recovery units, condensers, compressors, evaporators, raw material tanks and other auxiliary or additional technological equipment that are traditionally used in industrial embodiments, hydrocarbon conversion processes have not been described or demonstrated. Obviously, such related equipment can be used in industrial embodiments of the process circuits described herein. Such auxiliary or additional processing equipment may be acquired or constructed by a person skilled in the art without undue experimentation.

The drawing shows a method and apparatus 10 for producing low sulfur diesel fuel. The hydrocarbon feed is introduced into line 12 and can be distributed between the feed stream 14 and the quench stream 16. The feed stream is preheated and combined with hydrogen gas stream 18. A hydrogen gas stream may be supplied from a make-up gas compressor (not shown). In one aspect, the hydrogen in line 18 is supplied only by a make-up gas compressor supplied from a common hydrogen feed line of an oil refinery. The hydrogen gas stream from line 18 is mixed with the hydrocarbon feed of line 12 to produce a mixture of hydrocarbon feed and hydrogen in line 19.

Combined stream 19 is heated in a flame heater and fed to the first reaction zone 20 or hydrotreatment step. The first hydroprocessing reaction zone 20 may have more than one 024500 hydroprocessing reactor 22. The first hydroprocessing reaction zone 20 shown in the drawing has a first hydroprocessing reactor 22 and a second hydroprocessing reactor 24. The design may include more hydroprocessing reactors. Each of the hydroprocessing reactors 22, 24 may contain only one hydroprocessing catalyst bed 26 or include multiple hydroprocessing catalyst beds 26, 28. The quenching stream 16 can be bypassed by raw material heaters, separated and fed into the stream exiting the hydrotreatment catalyst bed or hydroprocessing reactor to cool the hot hydrotreated effluent. The first hydrotreated effluent exits the first hydrotreatment reaction zone 20 via line 30.

One or both of the hydroprocessing reactors 22, 24 in the hydroprocessing reaction zone 20 may be operated in a continuous liquid phase. Hydroprocessing in the continuous liquid phase includes the introduction of liquid-phase hydrocarbon feedstocks and hydrogen into the hydroprocessing reactor. Hydrogen must be present in a sufficiently low concentration to maintain a continuous liquid phase in the hydrotreatment reactor, but at a rather high concentration in order to introduce an amount of hydrogen sufficient for hydrotreating the hydrocarbon feed. In other words, a continuous space filled with a hydrocarbon liquid should extend from the feed inlet to the outlet of the reactor effluent 22, 24. Gaseous hydrogen may be present outside the space filled with the liquid, or inside the space in the form of gas plugs or bubbles. At a minimum, the volume of liquid in the reactor will be greater than the volume of gas in the same place.

During the hydroprocessing reactions occurring in the hydroprocessing reactor 22, 24, hydrogen is inevitably consumed. The hydrogen can be supplied in excess to the reactor in the first raw material inlet channel or additionally replaced with one or more hydrogen inlet points located downstream of the first raw material inlet channel (not shown). The flow rate of hydrogen added at the indicated downstream positions is controlled to ensure that the reactor operates in a continuous liquid phase. The maximum hydrogen flow rate that can be added to the reactor 22, 24 is less than the flow rate that would cause the transition from the continuous liquid phase to the continuous vapor phase.

In some aspects, the hydrocarbon feed does not contain a recycle product from a hydrotreatment reactor or other hydrocarbon diluent. In other aspects, a recycle stream or diluent (both not shown) can be included in fresh hydrocarbon feed prior to hydroprocessing to add additional volume to the reactor to add additional hydrogen bearing capacity to the hydrocarbon feed or to supply additional mass to reduce temperature rise in layer 26, 28 catalyst. In such aspects, any recycle product or diluent is typically introduced into the feedstock in line 14 before mixing the hydrogen stream of line 18 with the feed. Typically, such a recycle product can be pre-cleaned of vaporous hydrogen sulfide, nitrogen or nitrogen-containing compositions, as well as any other substances in the vapor phase.

In one aspect, fresh hydrocarbon feed in line 14 is supplied and mixed with a hydrogen stream of line 18 from a make-up gas compressor or other similar source of hydrogen. A stream of hydrogen is mixed into the fresh hydrocarbon feed of the hydrotreatment reaction zone 20 and supplied at a rate at least sufficient to satisfy the hydrogen demand of the first reactor 22 and the second reactor 24, if any. In some examples, the flow rate of added hydrogen will provide an excess of the specified hydrogen demand for the hydroprocessing reaction zone 20 as a reserve in the event that the hydrogen flow exceeds the calculated amount in a particular bed 26, 28 or reactor 22, 24.

In other aspects, hydrogen is added to the fresh feed stream to introduce an amount of hydrogen sufficient to exceed the saturation point of the hydrocarbon liquid so that a small amount of vapor phase is present in substantially the entire liquid phase. Thus, in some aspects, there is a sufficient amount of additional hydrogen in a small volume of the vapor phase for additional dissolved hydrogen to enter the continuous liquid hydrocarbon phase, since hydrogen is consumed in the reaction. For example, the amount of added hydrogen may be 10-20 wt.%. more than the total calculated hydrogen needs of each hydroprocessing catalyst bed 26, 28. In other aspects, it is contemplated that the amount of hydrogen can be up to a value of 100 to 1000% saturation based on the hydrocarbon saturated liquid phase. Excess hydrogen is transferred to the stream leaving the first hydroprocessing reactor 22, either in solution, in the gas phase, or in the gas phase, and in the solution as part of the effluent liquid stream 23, which transfers the effluent from the first hydroprocessing reactor 22 to the second hydroprocessing reactor 24. In this aspect, no other hydrogen is added to the hydroprocessing reaction zone 20. In other aspects, additional hydrogen may be added to the hydroprocessing reactors 22, 24. However, it should be noted that the amount of hydrogen added to the hydroprocessing reaction zone 20 may vary depending on the composition of the feedstock, operating conditions, the desired output, and other factors. In one aspect, a liquid hydrocarbon feed may have

- 4,024,500 in its composition from 67 to 135 nm ³ hydrogen per m ³ oil (from 400 to 800 standard cubic feet per barrel). In this aspect, a continuous gas phase may exist along with a continuous liquid phase extending from the feed inlet to the product outlet of each reactor 22, 24. Essentially, into the outlet from the catalyst bed 26, 28 or into each outlet of the reactor 22, 24 4 to 25 nm ^{3 of} hydrogen per m ^{3 of} oil can flow (from 25 to 150 std. cubic feet / barrel).

Hydrotreating, which takes place in the first hydrotreatment reaction zone, may include, without limitation, hydrotreating, such as hydrodesulfurization or formation of saturated compounds, hydrocracking, and hydroisomerization. In a preferred aspect, the first hydrotreatment reaction zone 20 is a hydrotreatment reaction zone 20. In this aspect, one or all of the hydroprocessing reactors 22, 24 are hydrotreating reactors 22, 24 with a single layer 26 or more layers 26, 28 of a hydrotreating catalyst. In addition, in said aspect, the first hydrotreated effluent may be a first hydrotreated effluent.

Although not shown, the first hydrotreated effluent in line 30 can be vaporized to separate the gas from the liquid and a pressure relief valve can be installed on the gas line to lower the pressure of the hydrotreatment reaction zone 20 in case of overpressure. The gas and liquid flow can be combined again downstream of the safety valve.

The fractionation zone 40 includes a fractionation column 42. In the fractionation column 42, the first hydrotreated exit stream entering through the inlet 31 is fractionated to produce a light gas stream in the exhaust gas line 44 and a diesel fuel stream in the bottoms stream 46. In a particular embodiment, the vapors from the top of the fractionation column 42 are withdrawn along the overhead line 48. Vapors from line 48 are condensed and collected in a receiver 50. Light gas is vented from the top of the receiver 50 through the exhaust gas line 44, and unstabilized naphtha is removed from the bottom of the receiver via line 52. The aqueous phase can be removed from the sump in the receiver 50. At least , part of the unstabilized naphtha can be returned as reflux to the fractionation column 42, while destabilized naphtha can be isolated in line 54 for further processing. The pressure in the upper part of the fractionation column 42 is in the range from 450 to 1150 kPa, and the temperature in the cube of the fractionation column 42 with the separation wall is in the range from 204 to 260 ° C. if the feed in line 12 is mainly feedstock boiling in the range boiling of diesel fuel, and from 232 to 315 ° C, if the raw materials in line 12 are mostly raw materials boiling in the boiling range of UO. Other cube temperatures may be suitable for various types of feed in line 12.

In one aspect, the fractionation column 42 may be a separation wall fractionation column 42. The separation wall 56 may divide the separation wall column 42 into separate compartments on the first side 58 and the second side 60. In this aspect, the first hydrotreated effluent is fed to the first side 58 of the separation column fractionation column 42 through the inlet 31, since the first side 58 communicates with the first hydroprocessing reaction zone 20 in front of it. A stream of diesel fuel is isolated in a cube of the first side 58 of the fractionation column 42 with a separation wall. In one aspect, the separation wall 56 extends to the bottom of the fractionation column 42 and is soldered to the bottom and the inner walls of the separation wall column to prevent hydraulic communication between the compartments on the first side 58 and the second side 60 in any position below the top of the separation wall 56. First exiting stream subjected to hydroprocessing, is fed to the first side 58 to the inlet channel 31 located below the top of the separation wall 56. The column with the separation wall may be a stripping column 42 with a separating wall, in which an injection of inert gas into the lower portion of the first side for stripping gaseous components from the descending liquid stream, instead of using a boiler. The inert gas may be hydrogen or steam, but steam is preferred. The diesel fuel stream may exit from the first side 58 through the diesel exhaust channel 43, which is located below the inlet channel 31 to the first side 58 on the bottom of the fractionation column 42. The temperature of the cube in the first side 58 of the separation wall fractionation column 42 is in the range from 204 to 260 ° C. if the feed in line 12 is mainly feedstock boiling in the diesel boiling range and from 232 to 315 ° C. if the feed in line 12, it is predominantly raw material boiling over the boiling range of OO.

Diesel fuel stream 46, which contains diesel fuel and may have heavier components, cannot be classified as an ITZI stream, since it can contain up to 50 to 700 parts by weight of sulfur per million. The inventors have found that this occurs when the first hydrotreatment reaction zone 20 is a hydrotreatment reaction zone in which continuous liquid phase operations are performed. Consequently, in order to obtain ILBI fuel, the diesel fuel stream must be subjected to additional hydrotreatment. In addition, the diesel stream in line 46 may require additional hydroprocessing to achieve the desired properties. In some cases, the diesel stream in line 46 may be subjected to additional

- 5,024,500 hydroprocessing directly if line 46 transfers the flow of diesel fuel. In one aspect, specifically, when the feedstock 12 is a heavier feedstock, such as DOO, the fractionation zone 40 includes a fractionation column 70, and the diesel stream in line 46 can be supplied to the fractionation column 70 via line 47.

In the fractionation column 70, diesel fuel is fractionated to supply vapor to line 72, which can be condensed and collected at receiver 74 to produce naphtha stream 76. Part of the naphtha stream can be returned as reflux to the fractionation column 70, and another part can be recovered as the product in line 78. From the bottom of the fractionation column, a hydrotreated heavy hydrocarbon product such as UO, which can be a very good raw material, can be recovered RCC installations or hydrocracking units. The fractionated diesel fuel stream in line 82 can be isolated as a side stream in the outlet channel 81 from the fractionation column 70. In one aspect, the side stream outlet channel 81 is positioned higher than the position where the diesel fuel stream in line 46 is fed from the fractionation column 42 to the fractionation column 70 via line 47 to the inlet 49. In another aspect, the fractionated diesel fuel stream in line 82 is collected in in the form of liquid coming from the device for collecting liquid on the plate of the fractionation column 70. The pressure in the upper part of the fractionation column 70 is in the range from 110 to 200 kPa absolute, and the temperature in the cube of the fractionation column 70 s is in the range from 316 to 371 ° C.

The diesel fuel stream, either in line 46 or in line 82, is fed to a second hydroprocessing reaction zone 90 or a step through line 84 of the original diesel fuel. In one embodiment, the second hydrotreatment reaction zone is in communication with the first side 58 of the fractionation column 42 with separation wall and the first hydrotreatment reaction zone 20 in front of it. If the diesel fuel stream in line 46 is the original diesel fuel stream, the control valve on line 83 is open and the control valves on lines 47 and 82 are closed. If the fractionated diesel fuel stream in line 82 is the original diesel fuel stream, the control valve on line 83 is closed and the control valves on lines 82 and 47 are open. It is assumed that you can use some intermediate option between the two specified modes. The diesel feed stream transported through line 84 represents at least a portion of the diesel fuel stream in line 46 from the bottom of the fractionation column 42 that is fed directly to the second hydroprocessing reaction zone 90, or the overhead obtained from the fractionation column 70 along the line 82. In a first aspect, the second hydrotreatment reaction zone 90 is connected to a fractionation column 70 upstream of it through a side outlet 81. In addition, the fractionation column 70 communicates with upstream of the second hydrotreatment reaction zone 90.

The diesel feed stream in line 84 is subjected to hydrogen treatment in a second hydrotreatment reaction zone 90 with a hydrotreatment catalyst to produce a second hydrotreatment effluent. The diesel feed stream in line 84 is preheated and combined with the hydrogen gas stream in line 85. The hydrogen gas stream can be supplied from a make-up gas compressor (not shown). In one aspect, the hydrogen in line 85 is supplied only by a make-up gas compressor supplied from a common hydrogen refinery feed line. The hydrogen gas stream from line 85 is mixed with the diesel feed stream in line 84 to form a mixture of the diesel feed stream and hydrogen in line 86.

Combined stream 86 is heated in a flame heater and fed to a second hydrotreatment reaction zone 90. The second hydroprocessing reaction zone 90 may have more than one hydroprocessing reactor 92. The second hydroprocessing reaction zone 90, shown in the drawing, has only one hydroprocessing reactor 92. The design may include more hydroprocessing reactors. Hydroprocessing reactors 92 may contain only one layer of hydroprocessing catalyst 94 or include multiple layers of hydroprocessing catalyst. The second hydrotreated effluent exits the second hydrotreatment reaction zone 90 to line 96.

The hydroprocessing reactor 92 in the second hydroprocessing reaction zone 90 can be operated in a continuous liquid phase, as explained in relation to the first hydroprocessing reaction zone 20. Hydrogen can be added to the hydroprocessing reactor 92, as explained in relation to the first hydroprocessing reaction zone 20. A product recycle or diluent may be fed to the hydroprocessing reactor 92, as explained in relation to the first hydroprocessing reaction zone 20.

Hydrotreating, which takes place in the second hydrotreatment reaction zone, may include, without limitation, hydrotreating, such as hydrodesulfurization, hydrocracking, and hydroisomerization. The hydroprocessing reactions activated in the second hydroprocessing reaction zone 90 may be the same as the hydroprocessing reactions activated in the first hydroprocessing reaction zone 20, or others. If the second hydrotreatment reaction zone 90 is a hydrotreatment reaction zone 90 and the first hydrotreatment reaction zone is a first hydrotreatment reaction zone 20, the second hydrotreatment zone 90 may be a second hydrotreatment reaction zone 90. IN

- 6,024,500 in this aspect, one or more hydroprocessing reactors 92 are hydrotreating reactors 92 with one bed 94 or more beds 94 of a hydrotreating catalyst. In addition, in said aspect, the second hydrotreated effluent in line 96 is the second hydrotreated effluent in line 96.

Most of the nitrogen and sulfur compounds are removed as gas leaving the fractionation column 42, so the second hydroprocessing catalyst in the second hydroprocessing zone 90 is much more efficient in converting the diesel source into usable products. In the absence of nitrogen and sulfur compounds, the hydrotreating catalyst, provided that it is used as a catalyst in the hydrotreating reactor 92, is effective for removing residual sulfur compounds in order to obtain the Ub8 fuel. In this aspect, the hydrotreated effluent, which may be a second hydrotreated effluent containing fuel 0.51). leaves the second reaction zone 90 hydroprocessing in line 96.

Although not shown, the second hydrotreated stream exiting line 96 can be vaporized to separate the gas from the liquid and a pressure relief valve can be installed on the gas line to lower the pressure of the hydrotreatment reaction zone 90 in case of overpressure. The gas and liquid flow can be combined again downstream of the safety valve.

The second hydrotreated effluent in line 96 can be fed to a fractionation column 42 to fractionate the second hydrotreated effluent with offgassing and unstabilized naphtha, as well as hydrotreated a diesel stream in line 98 exiting the second side cube 60 through the exhaust channel 99, which is located below the inlet channel 97. The hydrotreated diesel fuel in line 98 may be a diesel fuel stream with ultra-low sulfur content if the first and second hydrotreatment reaction zones 20 and 90, one or both of them, are hydrotreatment reaction zones.

In one aspect, the fractionation column 42 is a separation wall column, and a second hydrotreated effluent is supplied on the second side 60 of the separation wall 56 in the separation wall fractionation column 42 through the inlet 97, since the second side 60 of the separation fractionation column the wall communicates with the second hydroprocessing reaction zone 90 in front of it in the flow direction. The inlet channel 97 to the second side 60 is at a height below the top of the said separation wall 56. In one aspect, the separation wall 56 extends to the bottom of the fractionation column 42 with the separation wall and is soldered to the bottom and sides of the column with the separation wall to prevent communication between the first side 58 and the second side 60 in any position below the top of the dividing wall 56. The second hydrotreated effluent is fed to the second side 60 below the top of the dividing wall 56. To the baffle with a separation wall may be a stripping column 42 with a separation wall, in which inert gas is injected into the lower part of the first side to distill the gaseous components from the downward flow of liquid, instead of using a boiler. The inert gas may be hydrogen or steam, but steam is preferred. The temperature of the cube in the second side 60 of the fractionation column 42 with a separation wall is in the range from 204 to 260 ° C.

The hydrotreated diesel fuel stream is recovered in a cube of the second side 60 of the fractionation column 42 with a separation wall through the exhaust channel 99. The hydrotreated diesel fuel can be IL8I fuel if hydrotreatment zones 20 and 90, one or both of them, are hydrotreatment reaction zones .

Hydrotreating, which can be carried out in any of the hydrotreating reactors 22, 24 or 92, can be hydrotreating, which can also include the formation of saturated compounds and catalytic dewaxing. In hydrotreating, hydrogen gas is contacted with a hydrocarbon feed in the presence of suitable catalysts that are primarily active in removing heteroatoms, such as sulfur and nitrogen, from the hydrocarbon feed. During hydrotreating, unsaturated hydrocarbons become saturated. Suitable hydrotreating catalysts for use in the present invention are any conventional conventional hydrotreating catalysts and encompass catalysts that consist of at least one Group VIII metal, preferably iron, cobalt and nickel, more preferably cobalt and / or nickel, and at least one group VI metal, preferably molybdenum and tungsten, on a support material with a large surface area, preferably alumina. Other suitable hydrotreating catalysts include zeolite catalysts as well as noble metal catalysts in which the noble metal is selected from palladium and platinum. It is within the scope of the present invention that more than one type of hydrotreating catalyst is used in the same reaction vessel. Group VIII metal is usually present in an amount ranging from 2 to 20 wt.%, Preferably from 4 to 12 wt.%. Group VI metal is generally present in an amount ranging from 1 to 25 wt.%, Preferably from 2 to 25 wt.%

- 7,024,500

Preferred hydrotreatment reaction conditions include temperatures from 204 ° C (400 ° P) to 482 ° C (900 ° P), pressures from 3.5 MPa (500 psi) to 17.3 MPa (2500 psi), the hourly space velocity of liquid fresh hydrocarbon feeds is from 0.1 to 10 h ^-1 with respect to a hydrotreating catalyst or a combination of hydrotreating catalysts. In one aspect, the hydrotreated effluent with a lower sulfur concentration and higher cetane number than the corresponding hydrocarbon feeds leaves the hydrotreatment reaction zone 20 in line 30 and enters fractionation zone 40.

Hydroprocessing, which can be carried out in any of the hydroprocessing reactors 22, 24 or 92, may be hydrocracking. Hydrocracking refers to a process in which hydrocarbons are cracked to hydrocarbons with a lower molecular weight in the presence of hydrogen. Depending on the required output, the hydrocracking zone may comprise one or more layers of the same or different catalysts. In one aspect, for example, if the preferred products are middle distillates, amorphous supports or low active zeolite supports are used for the preferred hydrocracking catalysts in combination with one or more hydrogenation components based on metals of the VIII or νίΒ groups. In another aspect, when the preferred products relate to substances boiling in the boiling range of gasoline, the hydrocracking zone comprises a catalyst, which typically comprises any crystalline zeolite substrate active in cracking, onto which a relatively small amount of hydrogenation component is deposited based on metal of group VIII. Additional hydrogenation components can be selected from the νΊΒ group to combine with the zeolite substrate.

Zeolite substrates active in cracking are sometimes referred to in the art as molecular sieves and are usually composed of silica, alumina and one or more exchangeable cations, such as sodium, magnesium, calcium, rare earth metals, etc. In addition, they are characterized by crystalline pores with respect to the same diameter, from 4 to 14 angstroms (10 ^-10 m). It is preferable to use zeolites with a relatively high silica / alumina molar ratio of from 3 to 12. Suitable zeolites found in nature include, for example, mordenite, stilbit, heilandite, ferrierite, daciardite, chabazite, erionite and faujasite. Suitable synthetic zeolites include, for example, crystalline types Β, X, Υ and b, for example synthetic faujasite and mordenite. Preferred zeolites are materials with crystalline pore diameters in the range of 8-12 angstroms ( ^10-10 m), in which the silica / alumina molar ratio is from 4 to 6. One example of a zeolite falling in the preferred group is a synthetic molecular sieve Υ.

Naturally occurring zeolites are typically found in sodium form, alkaline earth form, or mixed forms. Synthetic zeolites are almost always obtained first in sodium form. In any case, for use as a cracking active substrate, it is preferable that most or all of the starting zeolite monovalent metals are ion-exchanged with the multivalent metal and / or ammonium salt, followed by heating to decompose the ammonium ions bound to the zeolite, leaving instead hydrogen ions and / or exchange centers, which actually underwent decationation as a result of additional removal of water. Zeolites Υ in hydrogen form or decationized zeolites Υ of this type are more specifically described in US patent 3130006.

Zeolites in the mixed form of a multivalent metal - hydrogen can be obtained as a result of ion exchange, first with an ammonium salt, and then partial reverse exchange with a multivalent metal salt and then calcination. In some cases, as in the case of synthetic mordenite, hydrogen forms can be prepared by direct acid treatment of the zeolites in alkaline form. In one aspect, preferred cracking active substrates are materials that are at least 10%, and preferably at least 20%, deficient in a metal cation, based on the initial ion exchange capacity. In another aspect, a desirable and stable class of zeolites is a group of materials in which at least 20% of the ion exchange capacity is saturated with hydrogen ions.

The active metals used in the preferred hydrocracking catalysts of the present invention as hydrogenation components are Group VIII metals, i.e. iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum. In addition to these metals, other promoters can also be used in conjunction with them, including νΊΒ group metals, such as molybdenum and tungsten. The amount of hydrogenation metal in the catalyst can vary widely. In General terms, you can use any amount from 0.05 to 30 wt.%. In the case of noble metals, it is generally preferable to use from 0.05 to 2 wt.%.

A method of introducing a hydrogenating metal is to contact the zeolite substrate material with an aqueous solution of a suitable compound of the desired metal, in which the metal is present in cationic form. After adding the selected hydrogenating metal or metals, the resulting catalyst powder is then filtered off, dried, granulated with added lubricants, binders or the like, if desired, and calcined in air at temperatures, for example, from 371 to 648 ° С ( from 700 to 1200 ° P) in order to activate the catalyst and the decomposition of ammonium ions. Alternatively, the zeolite component can first be granulated, followed by the addition of a hydrogenating component and activation by calcination.

The catalysts mentioned above can be used in undiluted form, or the zeolite powdery catalyst can be mixed and granulated together with other relatively less active catalysts, diluents or binders, such as alumina, silica gel, aluminosilicate coels, activated clays and the like, in ratios in ranges from 5 to 90 wt.%. These diluents can be used as such or they can contain a small proportion of the added hydrogenation metal, such as a metal of νίΒ and / or group VIII. Hydrocracking catalysts promoted by an additional metal can also be used in the method of the present invention, which encompass, for example, aluminophosphate molecular sieves, crystalline chromosilicates and other crystalline silicates. Crystalline chromosilicates are more fully described in US patent 4363718.

In accordance with one approach, hydrocracking conditions may include temperatures from 232 ° C (450 ° P) to 468 ° C (875 ° P), pressure from 3.5 MPa (500 psi) to 16, 5 MPa (2400 psi) and hourly volumetric fluid velocity (ΡΗδν) from 0.1 to 30 h ^-1 . In some aspects, the hydrocracking reaction process stream provides for the conversion of hydrocarbons to lower boiling products, which may be a conversion of at least 5 vol% of the process stream. In other aspects, the conversion per passage in the hydrocracking zone may be in the range of 15 to 70%, and preferably the conversion per passage is in the range of 20 to 60%. In such aspects, the methods provided herein are suitable for producing naphtha, diesel, or any other desired lower boiling hydrocarbons.

Hydrotreating, which can be carried out in any of the hydroprocessing reactors 22, 24, 92, may be hydroisomerization. Hydroisomerization also includes catalytic dewaxing. Hydroisomerization is a process in which in one aspect at least 10%, in another aspect at least 50%, and in another aspect from 10 to 90% of the n-paraffins of the hydrocarbon feed are converted to isoparaffins, which is effective for the outlet stream with at least one of the cloud point equal to 0 ° C (32 ° P) or lower, a pour point equal to 0 ° C (32 ° P) or lower, and / or the value of the limiting filterability temperature (СРРР) equal to 0 ° C (32 ° P) or lower. In general, such hydroisomerization conditions include temperatures from 260 ° C (500 ° P) to 371 ° C (700 ° P), pressures from 1.38 MPa (200 psi) to 8.27 MPa (1200 psi), hourly space velocity of fresh liquid hydrocarbon feeds is from 0.1 to 10 h ^-1 . However, other hydroisomerization conditions are also possible, depending on the specific types of raw materials to be processed, the composition of the sources of raw materials, the desired composition of the output stream and other factors.

Suitable hydroisomerization catalysts are any known conventional hydroisomerization catalysts. For example, suitable catalysts may include zeolite components, hydrogenation / dehydrogenation components and / or acidic components. In some forms, the catalysts may comprise at least one Group VIII metal, such as a noble metal (i.e., platinum or palladium). In other forms, the catalyst may also include silicoaluminophosphate and / or zeolite aluminosilicate. Examples of suitable catalysts are disclosed in US patents 5976351, 4960504, 4788378, 4683214, 4501926 and 4419220; however, other isomerization catalysts can also be used, depending on the composition of the feed, operating conditions, the desired output, and other factors.

Example.

To demonstrate the difficulty of desulfurization of diesel fuel to fuel υΡδΌ straight-run raw materials with a boiling range of diesel fuel having the properties shown in table. 1 was hydrotreated with a continuous liquid phase.

- 9,024,500

Table 1

ΑΡΙ 28.73 Sulfur, mass, ppm 1.37 Nitrogen, mass, ppm 150 Monoaromatic compounds,% wt. 21.7 Diaromatic compounds,% of the mass. 12.6 Polyaromatic compounds,% wt. 1.7 Bromine number 6 Distillation method ϋ-86 according to A5TM standards, ° Р (° С) Initial boiling point (ΊΒΡ) 510 5% 550 10% 561 thirty% 580 fifty% 593 70% 607 90% 630 95% 643 Final Temperature (EP) 659

The initial diesel fuel was hydrotreated on a nickel-molybdenum catalyst with an amorphous trefoil alumina support. The conditions included a continuous liquid phase with a degree of recirculation of 5 to 1 to ensure the presence of a sufficient amount of hydrogen in the solution. Other conditions for the implementation of the method, as well as the results are presented in table. 2.

table 2

On the basis of data on the degree of desulfurization under the indicated conditions, it was suggested that desulfurization in order to obtain Ub8i fuel cannot be achieved in the temperature range of 700-720 ° P (371-382 ° C) with a continuous liquid phase. If desulfurization with a continuous liquid phase were achievable at higher temperatures, the catalyst life would be so significantly reduced that operation under these conditions would be uneconomical.

The product obtained from hydrotreated USO boiling in the boiling range of diesel fuel had the properties shown in table. 3. The specified source diesel fuel is selected to simulate diesel fuel that has been hydrotreated and separated to remove hydrotreated products, such as hydrogen sulfide and ammonia, which may interfere with further hydrodesulfurization.

Table 3

ΑΡΙ 28.59 1 Sulfur, mass, ppm 554 Nitrogen, mass, ppm 246 Monoaromatic compounds,% wt. 42.3 Diaromatic compounds,% of the mass. 7.5 Polyaromatic compounds,% wt. 1,1 Bromine number 6 Distillation method according to A8TM standards, ° P (° C) ϋ-2287 ϋ-86 Initial boiling point (ΙΒΡ) 343 (173) 482 (250) 5% 416 (213) 10% 450 (232) 490 (254) thirty% 520 (271) 508 (264) fifty% 567 (297) 553 (289) 70% 608 (320) 583 (306) 90% 663 (351) 627 (331) 95% 686 (363) Final Temperature (EP) 755 (402) 635 (335)

The raw materials presented in table. 3, was hydrotreated in a continuous liquid phase to obtain fuel 0.81). The diesel fuel obtained by USO hydrotreating, although with a clearly relatively low sulfur content, is very difficult to hydrotreat to low sulfur concentrations, since the residual sulfur compounds are inert with respect to conversion. The hydrotreating catalyst used was nickel-molybdenum on an amorphous alumina substrate of 10,024,500 in the form of trefoils. The conditions of the method, as well as the results are presented in table. 4.

Table 4

HN8U calculated on fresh raw materials, ch1 1,02 Pressure, psi inch hut (kPa) 804 (5543) Temperature, ° Р (° С) 700 (371) Addition of hydrogen, std. cube ft / barrel (nm ³ / m ³ ) 384 (65) Hydrogen consumption, std. cube ft / barrel (nm ³ / m ³ ) 242 (41) Sulfur, mass, ppm 4 Nitrogen, mass, ppm 4

Despite the processing inert nature of the feed and the very low rate of hydrogen addition, hydrotreating in the continuous liquid phase managed to turn diesel-based feed into υΓδΓ fuel at higher temperatures. The inventors believe that hydrotreating this raw material in the continuous gas phase, a traditional operation in the irrigated layer, will allow to obtain fuel υΓδΌ in less severe conditions with the same success.

Without further elaboration, it is believed that, using the preceding description, one skilled in the art can apply the present invention to its fullest extent. Therefore, the above preferred specific embodiments are to be construed only as illustrative and not limiting the rest of the disclosure in any way.

In the foregoing description, all temperatures are given in degrees Celsius, and all parts and percentages are by weight unless otherwise indicated.

Based on the foregoing description, a specialist in the art can easily identify the essential characteristics of the present invention and, within its essence and scope, can make various changes and modifications of the invention to adapt it to a variety of options and application conditions.

Claims (9)

CLAIM 1. A device for hydrotreating a hydrocarbon feedstock, comprising a first hydrotreatment reaction zone for hydrotreating said hydrocarbon feedstock; a fractionation column with a dividing wall extending to the bottom of said fractionation column, which separates the fractionation column into a first side and a second side, said first side being connected to said first hydroprocessing reaction zone upstream and provided with an outlet channel located in the cube of the column diesel fuel; a second hydrotreatment reaction zone connected to an upstream said first side of said fractionation column with a separation wall, said second hydroprocessing reaction zone for hydroprocessing a diesel fuel stream from said first side of said fractionation column with a separation wall; the second side of the said fractionation column with a separation wall, which is connected to the second hydrotreatment reaction zone located upstream of it and provided with an outlet channel for the hydrotreated diesel fuel, and the fractionation column with a separation wall is designed so as to exclude communication between the exits located in the cube columns of the diesel exhaust channel and the hydrotreated diesel exhaust channel. 2. The device according to claim 1, in which the exhaust channel of diesel fuel from said first side is located below the inlet channel to the first side. 3. The device according to claim 1, in which the inlet channel to the first side is at a height below the top of said dividing wall. 4. The device according to claim 1, in which the inlet channel to the second side is at a height below the top of the said dividing wall. 5. The device according to claim 1, further comprising a fractionating column connected to the cube of said first side and located downstream. 6. The device according to claim 5, wherein said second hydrotreatment reaction zone is connected to said fractionating column and is located downstream. 7. The device according to claim 6, wherein said second hydrotreatment reaction zone is connected to said fractionating column through a lateral outlet channel of the fractionating column. 8. The method of hydrotreating a hydrocarbon feed using the device according to claim 1, wherein said hydrocarbon feed is subjected to hydrogen hydrotreatment in a first hydrotreatment reaction zone with a hydrotreatment catalyst under conditions effective to produce a first hydrotreated effluent; - 11,024,500 carry out fractionation of said first hydrotreated effluent in the first side of the separation wall in the fractionation column with a separation wall to obtain an initial diesel fuel stream separated from the cube of said fractionation column with a separation wall; the initial diesel fuel stream, or at least a portion of it, is hydrotreated with hydrogen in a second hydrotreatment reaction zone with a hydrotreatment catalyst to obtain a second hydrotreated effluent; fractionating said second hydrotreated effluent in a second side of said separation wall in said fractionation column with a separation wall to produce a hydrotreated diesel fuel stream. 9. The method of claim 8, in which on one or both sides of the said dividing wall serves gas for distillation of light components.