KR101586887B1 - Process and apparatus for producing diesel - Google Patents

Abstract

A method and apparatus for hydrocracking a hydrocarbon feed in a hydrocracking unit and hydrotreating the diesel product from a hydrocracking unit in a hydrotreating unit is disclosed. The hydrocracking unit and the hydrotreating unit may share the same recycle gas compressor. The mke-up hydrogen stream can also be compressed in the recycle gas compressor. The warming separator separates the recycle gas and the hydrocarbon from the diesel of the hydrotreating effluent, and thus the fractionation of the diesel is relatively simple. The warming separator also maintains the diesel product separately from the sulfur-rich diesel of the hydrocracked effluent and still retains the heat necessary for the fractionation of the light components from the low-sulfur diesel product.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a diesel-

Priority claim of early international application

This application is related to U.S. Serial No. 13 / 076,608, filed March 31, 2011; U.S. Application No. 13 / 076,631, filed March 31, 2011; U.S. Application No. 13 / 324,186, filed December 13, 2011; And U.S. Application Serial No. 61 / 549,978, filed October 21, 2011.

Technical field

The field of the invention is the production of diesel by hydrocracking.

Hydrocracking refers to the process of decomposing hydrocarbons to lower molecular weight hydrocarbons in the presence of hydrogen and a catalyst. Depending on the desired output, the hydrocracking zone may comprise one or more beds of the same or different catalysts. Hydrocracking is a process used to decompose hydrocarbon feeds such as Vacuum Gas Oil (VGO) into diesel containing kerosene and gasoline vehicle fuels.

Mild hydrocracking is generally used to convert Fluid Catalytic Cracking (FCC) to improve the quality of the unconverted oil that can be fed to the downstream unit while converting a portion of the feed to a harder product such as diesel. ) Or upstream of another process unit. Because global demand for diesel motor fuels is on the rise compared to gasoline motor fuels, moderate hydrocracking is considered to be to dampen product slate to diesel at the expense of gasoline. Light hydrocracking can be operated less rigorously than partial or total conversion hydrocracking, which balances diesel production with FCC units that are primarily used to form naphtha. Partial or total conversion Hydrocracking is used to make the diesel so that the yield of non-conversion oil available to the downstream unit is small.

Due to environmental concerns and newly established rules and regulations, marketable diesel must meet even lower tolerances for contaminants such as sulfur and nitrogen. The new regulations basically require the complete removal of sulfur from the diesel. For example, Ultra Low Sulfur Diesel (ULSD) requirements are typically less than 10 wppm sulfur.

Accordingly, there is a continuing need for improved methods of producing more diesel from gasoline feedstocks than gasoline. Such a method must ensure that the diesel product meets even more stringent product requirements.

In a method embodiment, the present invention includes a diesel manufacturing process for making a diesel from a hydrocarbon stream, comprising compressing a make-up hydrogen stream in a compressor to provide a compressed supplemental hydrogen stream . The hydrocracked hydrogen stream is obtained from a compressed supplemental hydrogen stream. The hydrocarbon stream is hydrocracked in the presence of a hydrocracked hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. At least a portion of the hydrocracked effluent stream is fractionated to provide a diesel stream. The diesel stream is hydrotreated in the presence of a hydrotreating hydrogen stream and a hydrotreating catalyst to provide a hydrotreating effluent stream.

In another method embodiment, the present invention further comprises separating the hydrocracked effluent stream into a hydro-hydrocracked effluent stream comprising hydrogen and a liquid hydrocracked effluent stream. The steam hydrocracking effluent stream is compressed to provide a compressed hydrogen stream. The hydrotreating hydrogen stream is obtained from the compressed hydrogen stream.

In another variant, the present invention further comprises separating the hydrotreated effluent stream into a hydrotreated effluent stream comprising hydrogen and a liquid hydrotreated effluent stream. The hydrotreated effluent stream comprising hydrogen is mixed with the hydrocracked effluent stream.

In another method embodiment, the present invention comprises a diesel manufacturing process for producing a diesel from a hydrocarbon stream, comprising the step of compressing a supplemental hydrogen stream in a compressor to provide a compressed supplemental hydrogen stream. The compressed supplemental hydrogen stream is further compressed in the recycle gas compressor to provide a compressed hydrogen stream. The hydrocracked hydrogen stream is obtained from a compressed hydrogen stream. The hydrocarbon stream is hydrocracked in the presence of a hydrocracked hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. At least a portion of the hydrocracked effluent stream is fractionated to provide a diesel stream. The diesel stream is hydrotreated in the presence of a hydrotreated hydrogen stream and a hydrotreating catalyst to provide a hydrotreated effluent stream.

In another method embodiment, the present invention further comprises a diesel manufacturing process for producing a diesel from a hydrocarbon stream comprising compressing a supplemental hydrogen stream in a compressor to provide a compressed supplemental hydrogen stream. The hydrocarbon stream is hydrocracked in the presence of a hydrocracked hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. The hydrocracked effluent stream is separated into a hydro-hydrocracked effluent stream comprising hydrogen and a liquid hydrocracked effluent stream. The steam hydrocracking effluent stream and the compressed supplemental hydrogen stream are compressed to provide a compressed hydrogen stream. The hydrocracked hydrogen stream and the hydrotreated hydrogen stream are obtained from the compressed hydrogen stream. The liquid hydrocracking effluent stream is fractionated to provide a diesel stream. The diesel stream is hydrotreated in the presence of a hydrotreated hydrogen stream and a hydrotreating catalyst to provide a hydrotreated effluent stream.

In another variant, the invention comprises a diesel production process for producing diesel from a hydrocarbon stream, comprising the step of compressing a supplemental hydrogen stream in a compressor to provide a compressed supplemental hydrogen stream. The compressed supplemental hydrogen stream is compressed in a recycle gas compressor to provide a compressed hydrogen stream. The hydrocracked hydrogen stream is obtained from a compressed hydrogen stream. The hydrocarbon stream is hydrocracked in the presence of a hydrocracked hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. At least a portion of the hydrocracked effluent stream is fractionated to provide a diesel stream. The diesel stream is hydrotreated in the presence of a hydrotreated hydrogen stream and a hydrotreating catalyst to provide a hydrotreated effluent stream. Finally, at least a portion of the hydrotreating effluent stream comprising hydrogen is mixed with at least a portion of the hydrocracked effluent stream.

In a device embodiment, the present invention is a diesel manufacturing device for manufacturing a diesel comprising a hydrocracking reactor in communication with a hydrocarbon feed line and at least one compressor on a supplemental hydrogen line for hydrocracking a hydrocarbon stream into hydrocarbons with lower boiling point And a diesel production apparatus. The recycle gas compressor is in communication with the hydrocracking reactor to compress the hydro-hydrocracked effluent stream comprising hydrogen to provide a compressed hydrogen stream to the recycle hydrogen line. To produce a low-sulfur diesel by hydrotreating the diesel stream, a hydrotreating reactor is in communication with the compressed hydrogen line and the hydrocracking reactor.

In another embodiment, the present invention provides a process for separating a hydrotreated effluent stream into a hydrotreated effluent stream comprising the hydrogen of the overhead line and a liquid hydrotreated effluent stream of the bottom line, a warm separator, and a recycle gas compressor in communication with the overhead line.

In a further apparatus embodiment, the present invention is a diesel manufacturing apparatus for manufacturing a diesel comprising a diesel manufacturing apparatus comprising a supplemental hydrogen stream, wherein at least one compressor is in communication with a supplemental hydrogen line for compressing the supplemental hydrogen stream. The hydrocarbon feed line is for transporting the hydrocarbon stream. The hydrocracking reactor is in communication with a supplemental hydrogen line and a hydrocarbon feed line for hydrocracking the hydrocarbon stream to lower boiling hydrocarbons. A recycle gas compressor is in communication with the hydrocracking reactor to compress the hydrocracking effluent stream comprising hydrogen to provide a compressed hydrogen stream to the compressed hydrogen line. A fractionation section is in communication with the hydrocracking reactor to fractionate the liquid hydrocracking effluent stream to produce a diesel stream delivered in the diesel line. To produce a low sulfur diesel by hydrotreating the diesel stream, the hydrotreating reactor is in communication with the compressed hydrogen line and the diesel line.

In another embodiment, the present invention relates to a diesel manufacturing apparatus for producing diesel comprising a diesel engine comprising a hydrocracking reactor for communicating with a compressor on a hydrocarbon feed line and a supplemental hydrogen line and for hydrocracking a hydrocarbon stream into hydrocarbons of low boiling point, Manufacturing apparatus. A recycle gas compressor is in communication with the hydrocracking reactor and the supplemental hydrogen line to compress the hydrocracking effluent stream and the compressed supplemental hydrogen stream comprising hydrogen to obtain a compressed hydrogen stream in the compressed hydrogen line. Finally, a hydrotreating reactor is in communication with the compressed hydrogen line and the hydrocracking reactor to hydrotreate the diesel stream to produce the low sulfur diesel.

In a variant of the apparatus, the invention further comprises a diesel manufacturing apparatus comprising a supplemental hydrogen line. In order to compress the supplemental hydrogen stream, one or more compressors are in communication with the supplemental hydrogen lines. The hydrocarbon feed line is for transporting the hydrocarbon stream. To hydrocrack the hydrocarbon stream to lower boiling hydrocarbons, the hydrocracking reactor is in communication with the supplemental hydrogen line and the hydrocarbon feed line. The recycle gas compressor is in communication with the hydrocracking reactor and one or more compressors to compress the hydro-hydrocracked effluent stream and the compressed, complementary hydrogen stream comprising hydrogen to provide a compressed hydrogen stream to the compressed hydrogen line. The fractionating section is in communication with the hydrocracking reactor to fractionate the liquid hydrocracking effluent stream to produce a diesel stream delivered in the diesel line. Finally, a hydrotreating reactor is in communication with the compressed hydrogen line and the diesel line to hydrotreate the diesel stream to produce the low sulfur diesel.

In another embodiment, the present invention is a diesel production apparatus for producing diesel comprising: a hydrocracking reactor in communication with at least one compressor on a hydrocarbon feed line and a supplemental hydrogen line, for hydrocracking the hydrocarbon stream into hydrocarbons having lower boiling points, And a diesel engine. A recycle gas compressor is in communication with the supplemental hydrogen line and the hydrocracking reactor to compress the vaporized hydrocarbon effluent stream comprising hydrogen to provide a compressed hydrogen stream to the compressed hydrogen line. The hydrotreating reactor is in communication with the compressed hydrogen line and the hydrocracking reactor to hydrotreate the diesel stream to produce the low sulfur diesel. In order to separate the hydrotreating effluent stream into a hydrotreated effluent stream comprising the hydrogen of the overhead line and a liquid hydrotreated effluent stream of the bottom line, the warm separator is in communication with the hydrotreating reactor. Finally, the recirculating compressor communicates with the overhead line.

1 is a simplified process flow diagram of an embodiment of the present invention.
Figure 2 is a simplified process flow diagram of a modification of the present invention.

Justice

The term "communication " means that material flow between the listed components is operationally permitted.

The term "downstream communication " means that at least a portion of the material flowing into the subject in a downstream communication manner can flow operatively from an object in communication with the subject.

The term "upstream communication " means that at least a portion of the material flowing from the subject in an upstream communication manner is operable to flow into a subject communicating with the subject.

The term "column " means a distillation column or columns for separating one or more components of different volatility. Unless otherwise indicated, each column includes a condenser, which condenses a portion of the overhead stream over the column overhead and refluxes back to the top of the column, and a condenser that evaporates a portion of the bottom stream at the bottom of the column and sends it back to the bottom of the column And includes a reboiler. The feed to the column may be preheated. The top pressure is the pressure of the overhead vapor at the vapor outlet of the column. The bottom temperature is the liquid bottom outlet temperature. The overhead and bottom lines refer to the net line from the column to the column downstream of reflux or reboiler.

As used herein, "True Boiling Point" (TBP) determines the boiling point of a material corresponding to ASTM D2892 for the production of standardized quality liquefied gases, distillate fractions and residues to obtain analytical data And the yield of said fraction by both mass and volume forming a graph of temperature versus distillation mass% using 15 theoretical plates in a column with a reflux ratio of 5: 1.

As used herein, the term " conversion "refers to the conversion of a feed into a boiling material below the diesel boiling range. The cut point of the diesel boiling range is between 343 ° C and 399 ° C (650 ° F to 750 ° F) using the actual boiling point distillation method.

As used herein, the term "diesel boiling range" is between 132 ° C and 399 ° C (270 ° F to 750 ° F) using the actual boiling point distillation method.

details

Moderate hydrocracking reactors operate with low stringency and thus low conversion rates. Diesel produced from moderate hydrocracking is not of sufficient quality to meet applicable fuel specifications, especially for sulfur. As a result, diesel produced from moderate hydrocracking must be treated in a hydrotreating unit that allows blending to the final diesel. In many cases, it is beneficial to integrate a moderate hydrocracking unit and a hydrotreating unit to reduce capital and operating costs.

A typical hydrocracking unit has both a low temperature separator and a low temperature flash drum. Hydrocracking units are often, but not always, equipped with a hot separator and a hot flash drum. A typical hydrotreating unit has only a low temperature separator. The cryogenic separator can be operated at a lower temperature to obtain optimum hydrogen separation for use as a recycle gas, but it proves to be thermally inefficient because the hydrotreated liquid stream must be reheated for fractionation to obtain the low sulfur diesel .

To avoid this cooling and reheating without affecting the hydrogen separation, the hydrotreating unit is utilized in parallel with the hydrocracking unit, the co-recycle gas compressor and the cryogenic separator. The recycle gas is divided into individual units after compression. The supplemental gas may be added to the recycle gas stream upstream from the recycle gas compressor. The supplemental gas may be added upstream of the recycle gas compressor to utilize a recycle gas compressor for compressing the hydrogen supplied to the hydrocracking reactor and the hydrotreating reactor.

The hydrotreating unit may employ a heat separator that extracts the warmed liquid product and then combines the hydrotreated effluent stream with the hydrocracked effluent. This configuration allows the hydrotreating and hydrocracking unit to operate at similar pressures. Additionally, the steam hydrotreated effluent may be transferred to a cryogenic separator to further separate the hydrogen from the hydrocarbons to provide a recycle gas. The liquid hydrotreated effluent from the warm separator does not need to be reheated long before fractionation. Moreover, since the liquid hydrotreating effluent mainly comprises low sulfur diesel, the fractionation of low sulfur diesel is simpler.

The present invention comprises dividing both the supplemental gas and the recirculating gas between the hydrocracking unit and the hydrotreating unit. The addition of the supplemental gas to the hydrocracking unit is beneficial because the feedstock to the hydrocracking reactor typically has many coke precursors that result in higher catalyst deactivation rates and shorter catalyst life. The use of a supplemental gas to increase the hydrogen partial pressure in the hydrocracking reactor will make the hydrocracking process more efficient.

The apparatus and method 8 for producing diesel comprises a compression section 10, a hydrocracking unit 12, a hydrotreating unit 14 and a fractionation zone 16. The hydrocarbon feed is first fed to the hydrocracking unit 12 and converted to the lower boiling point hydrocarbon containing diesel. The diesel is fractionated within the fractionation section and transported to the hydrotreating unit 14 to provide low-sulfur diesel.

The supplemental hydrogen stream in the supplemental hydrogen line 20 is supplied to one or more series of compressors 22 in the compression section 10 to increase the pressure of the supplemental hydrogen stream and to provide a compressed supplemental stream to the line 26 . The compressed supplemental stream in the compressed supplemental hydrogen line 26 may be combined with a vapor hydrocracked effluent stream comprising hydrogen in the overhead line 42 to provide an inductive hydrogen stream in line 28. The compressed supplemental hydrogen stream may be added to the vapor hydrocracking effluent stream at a predetermined location upstream of the recycle gas compressor 50 so that the recycle gas compressor 50 is connected to the hydrogenation cracking reactor 36 or a hydroprocessing reactor such as a hydrotreating reactor 92. [ As a result, no hydroprocessing reactor is disposed between the compressed hydrogen line 26 and the recycle gas compressor 50.

The inductive hydrogen stream in line 28 comprising the compressed supplemental hydrogen stream and the vapor hydrocracked effluent stream is fed to a recycle gas compressor (not shown) to provide a compressed hydrogen stream in the compressed hydrogen line 52, 50). The recycle gas compressor 50 is in downstream communication with the hydrocracking reactor 36, the supplemental hydrogen line 20 and the one or more compressors 22.

In an embodiment, the compressed supplemental hydrogen stream may be added to the compressed hydrogen line 52 downstream of the recycle gas compressor 50. However, the pressure of the compressed hydrogen stream in line 52 is too large to allow for supplemental hydrogen stream without adding more compressors on the supplemental hydrogen line 20. As a result, despite the increased duty for the recycled gas compressor 50 due to the higher throughput, the compressed hydrocyanation stream in the vapor hydrocracking effluent stream in line 42, upstream of the recycle gas compressor 50, May be beneficial. However, adding the compressed supplemental hydrogen stream upstream of the recycle gas compressor 50 may reduce the need for an additional compressor 22 on the supplemental hydrogen line 20. [

The compressed hydrogen stream in line 52 may be split into two hydrogen streams in division 54. [ The first hydrocracked hydrogen stream is obtained from the compressed hydrogen stream in the compressed hydrogen line 52 in the fraction 54 of the first hydrogen split line 30. The second hydrogen treated hydrogen stream is obtained from the compressed hydrogen stream in the compressed hydrogen line 52 at the branch 54 of the second hydrogen split line 56. The first hydrogen split line 30 is in communication with the hydrocracking reactor 36 and the second hydrogenated hydrogen stream in the second hydrogen split line 56 is in communication with the hydrotreating reactor 92.

The hydrocracked hydrogen stream in the first hydrogen split line 30 obtained from the compressed hydrogen stream in line 52 can be combined with the hydrocarbon feed stream in line 32 to provide a hydrocracked feed stream in line 34 .

The compressed supplemental hydrogen stream in line 26 may also be combined with the compressed hydrogen stream downstream of fraction 54 so that the supplemental hydrogen is introduced into hydrocracking reactor 36 which is not charged with the recycle hydrogen stream in line 52. [ Or to supply the necessary hydrogen to the hydrotreating reactor 92. When the compressed supplemental hydrogen stream in line 26 is combined with the compressed hydrogen stream upstream of the fractionator 54, it is possible for the supplemental gas to be delivered to the hydrocracking unit 12 as well as to the hydrotreating unit 14.

The hydrocarbon feed stream is introduced into line 32, possibly through a surge tank. In one aspect, the methods and apparatus described herein are particularly useful for hydrotreating process hydrocarbon feedstocks. Exemplary hydrocarbon feedstocks include atmospheric pressure diesel, VGO, deasphalting residues, reduced pressure residues, and atmospheric residues, coker distillates, straight run distillates, solvent deasphalted oils, boiling point such as -deasphalted oil, pyrolysis-derived oil, high-boiling synthetic oil, cycle oil, hydrocracking feed, cat cracker distillate, Lt; 0 > C (550 [deg.] F). These hydrocarbon feedstocks may contain from 0.1 to 4% by weight of sulfur.

Suitable hydrocarbon feedstocks are VGO or other hydrocarbon moieties that boil at a temperature of at least 50%, usually at least 75% by weight of the components, at temperatures above 399 [deg.] C (750 [deg.] F). Typical VGOs typically have a boiling range of 315 DEG C (600 DEG F) to 565 DEG C (1050 DEG F).

Hydrocracking refers to the process by which hydrocarbons are decomposed into lower molecular weight hydrocarbons in the presence of hydrogen. The hydrocracking reactor 36 is in downstream communication with the at least one compressor on the hydrocarbon feed line 32 and the supplemental hydrogen line 20. The hydrocracking feed stream in line 34 may be heat exchanged with the hydrocracking effluent stream in line 38 and may be operated prior to entering the hydrocracking reactor 36 for hydrocracking the hydrocarbon stream to lower boiling hydrocarbons Can be further heated in the heater.

The hydrocracking reactor 36 may comprise various combinations of one or more vessels, a plurality of catalyst beds in each vessel, and a hydrotreating catalyst in one or more vessels and a hydrocracking catalyst. In some embodiments, the hydrocracking reaction converts total amounts of products that boil below the diesel cut point to an amount that is greater than at least 20 percent by volume, typically greater than 60 percent by volume, of the hydrocarbon feed. The hydrocracking reactor 36 can operate with more than 50 volume percent of the feed, based on the total conversion, or with a complete conversion of at least 90% of the feed. Total conversion is effective to maximize diesel. The first vessel or bed may comprise a hydrotreating catalyst for the purpose of demineralizing, hydrodesulfurizing or denitrifying the hydrocracked feed.

Hydrocracking reactor 36 can operate under moderate hydrocracking conditions. The moderate hydrocracking conditions will provide a total conversion of the boiling product to less than 20 to 60 volume percent, preferably 20 to 50 volume percent, of the diesel cut point of the hydrocarbon feed. In moderate hydrocracking, the converted product is biased towards diesel. In a moderate hydrocracking process, the hydrotreating catalyst acts as much as or more than the hydrocracking catalyst. The conversion across the hydrotreating catalyst may be a substantial portion of the overall conversion. If the hydrocracking reactor 36 is intended for moderate hydrocracking, the moderate hydrocracking reactor 36 may be equipped with a bed of several hydrocracking catalysts, all hydrocracking catalysts, . In the last case, a bed of a hydrocracking catalyst may be followed by a bed usually made up of a hydrotreating catalyst. Most commonly, there may be zero beds, one bed or two beds of hydrocracking catalyst in three beds consisting of hydrotreating catalysts.

The hydrocracking reactor 36 of FIG. 1 has four beds in one reactor vessel. When moderate hydrocracking is desired, it is contemplated that the first three catalyst beds comprise a hydrotreating catalyst and the last catalyst bed comprises a hydrocracking catalyst. If partial or complete hydrocracking is preferred, more beds of hydrocracking catalyst may be used than in moderate hydrocracking.

Under moderate hydrocracking conditions, the feed is selectively converted to heavy products such as diesel and kerosene, where the yield of lighter hydrocarbons such as naphtha and gas is low. The pressure is also suitable to limit the hydrogenation of the bottom product to the optimum level for downstream treatment.

In one embodiment, for example, when the balance of gasoline and the middle distillate is desired in the transformed product, the moderate hydrocracking can be carried out in the first hydrocracking reactor 36 with the hydrocracking catalyst, A low-level zeolite base or an amorphous silica-alumina base combined with the above-mentioned Group VIII or VIB metal hydride components. In other embodiments, when the intermediate distillate in the converted product is highly preferred over the gasoline product, partial or complete hydrocracking typically involves any crystalline zeolite decomposition base on which the Group VIII metal hydrogenation component is deposited and deposited Can be carried out in a first hydrocracking reactor (36) with a catalyst. Other hydrogenation components may be selected from the group VI to incorporate with the zeolite base.

Zeolite decomposition bases are often referred to in the art as molecular sieves and are typically comprised of salicas, alumina, and one or more substitutable cations such as sodium, magnesium, calcium, rare earth metals, and the like. They further feature a relatively uniform diameter pore of 4 to 14 angstroms (10 ^-10 meters). It is preferable to employ a zeolite having a relatively high silica / alumina molar ratio of 3 to 12. Suitable zeolites found in nature include, for example, mordenite, stilbite, heulandite, ferrierite, dachiardite, chabazite, Erionite and faujasite. ≪ / RTI > Suitable synthetic zeolites include, for example, B, X, Y and L crystalline forms, such as synthetic faujasite and mordenite. Preferred zeolites are those having a crystal pore diameter of 8 to 12 angstroms (10 ^-10 meters), wherein the silica / alumina mole ratio is 4 to 6. One example of a preferred group of zeolites is the synthetic Y-type molecular sieve.

Naturally occurring zeolites are usually found in sodium form, alkaline earth metal form or mixed form. Synthetic zeolites are almost always produced in sodium form. In any case, when used as a decomposition base, it is preferred that most or all of the original zeolite 1 is ion-exchanged with a multivalent metal and / or ammonium salt and then heated to decompose the ammonium ion associated with the zeolite , Which leaves a substantially de-cationized exchange site in situ by further removal of hydrogen ions and / or water. Hydrogen or "decationized" Y type zeolites of this nature are described more fully in US 3,130,006.

The mixed multivalent metal-hydrogen zeolite can be prepared by first ion-exchanging with an ammonium salt, then partially re-exchanging with a metal salt, and then calcining. In some cases, as in the case of synthetic mordenite, the hydrogen form can be prepared by direct acid treatment of the alkali metal zeolite. In one embodiment, the preferred degradation base is a metal-cation deficiency of at least 10%, preferably at least 20%, based on initial ion exchange performance. In another embodiment, the preferred and stable class of zeolites is that 20% or more ion exchange performance is met by hydrogen ions.

The active metals employed in the preferred hydrocracking catalysts of the present invention as the hydrogenation component are metals of the Group VIII metals, namely iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum. In addition to these metals, other cocatalysts, including metals of group VIB, such as molybdenum and tungsten, may also be used with the metal. The amount of hydrogenated metal in the catalyst can vary within wide limits. In general, any amount in the range of from 0.05% by weight to 30% by weight can be used. In the case of a noble metal, it is preferable to use 0.05 to 2% by weight.

A method of incorporating a hydride metal is to contact an aqueous solution of a suitable compound of the desired metal with the base material, wherein the metal is present in the form of a cation. After the addition of the selected hydrogenation metal (s), the resulting catalyst powder is filtered, dried, pelletized, if necessary with the addition of a lubricant, binder, etc., And calcined in air at a temperature of 648 ° C (700 ° F to 1200 ° F). Alternatively, the base component can be first pelletized and then the hydrogenation component added and activated by calcination.

The above catalysts may be employed in a non-diluted form, or the powder catalyst may be present in a proportion ranging from 5 to 90% by weight with other relatively less active catalysts, diluents or binders such as alumina, silica gel, silica- Clay, etc., or co-pelleted. These diluents may be employed on their own or may comprise a small proportion of the added hydrogenation metal, such as Group VIB and / or Group VIII metals. The process of the present invention may also utilize additional metal promoted meld hydrocracking catalysts including, for example, aluminophosphate molecular sieves, crystalline chromosilicates and other crystalline silicates. Crystalline chromosilicates are described in more detail in US 4,363,718.

According to one approach, the hydrocracking conditions include a temperature of 290 ° C (550 ° F) to 468 ° C (875 ° F), preferably between 343 ° C (650 ° F) and 435 ° C (815 ° F) 500 psig) to 20.7 MPa pressure (3000 psig), 1.0 to 2.5 hr ^-1 liquid hourly space velocity of less than (liquid hourly space velocity; LHSV), and 421 to 2,527 Nm ³ / m ³ oil (2,500 to 15,000 scf / bbl ) ≪ / RTI > When moderate hydrocracking is desired, the conditions may range from 600 ° F to 825 ° F., from 5.5 to 13.8 MPa (gauge) (800 to 2000 psig) or, more typically, from 6.9 to 11.0 A liquid hourly space velocity (LHSV) of from 0.5 to 2 hr ^-1 , preferably from 0.7 to 1.5 hr ^-1 , and from 421 to 1,685 Nm ³ / m ³ oil (2,500 psig) To 10,000 scf / bbl).

The hydrocracked effluent exits the hydrocracking reactor (36) via line (38). The hydrocracked effluent in line 38 is heat exchanged with the hydrocracked feed in line 34 and may be cooled prior to entering the cryogenic separator 40 in an embodiment. The cryogenic separator (40) communicates downstream with the hydrocracking reactor (36). The cryogenic separator is a hydrocracking reactor 36 (< RTI ID = 0.0 > 36 < / RTI > to 63 C (115 F to 145 F), resulting in a pressure drop to maintain hydrogen and light gases in the overhead and the normally liquid hydrocarbons at the bottom Lt; RTI ID = 0.0 > pressure. ≪ / RTI > Cryogenic separator 40 provides a hydrocracking effluent stream comprising hydrogen to cryogenic separator overhead line 42 and a liquid hydrocracking effluent stream to cryogenic separator bottom line 44. The cryogenic separator also has a boot for collecting an aqueous phase in line 46. The vapor hydrocracking effluent stream in overhead line 42 is scrubbed with a solution to remove ammonia and hydrogen sulphide as before, prior to recirculation of the hydro-hydrocracked effluent stream comprising hydrogen to recycle gas compressor 50 .

At least a portion of the hydrocracked effluent stream 38 may be fractionated in a fractionation section 16 that communicates downstream with the hydrocracking reactor 36 to produce a diesel stream in line 86. In one aspect, liquid hydrocracking effluent stream 44 can be fractionated in fractionation section 16. In another aspect, the fractionation section 16 may comprise a low temperature flash drum 48. The liquid hydrocracking effluent stream 44 is maintained at the same temperature as the cryogenic separator 40 to provide a light liquid stream from the liquid hydrocracking effluent stream to the bottom line 62 and a hard end stream to the overhead line 64 , But may be flash in a low temperature flash drum 48 operable at a lower pressure of 1.4 MPa to 3.1 MPa (gauge) (200 to 450 psig). The aqueous stream in line 46 from the boot of the cryogenic separator may also be directed to the cryogenic flash drum 48. The flash aqueous stream is removed from the boot of the low temperature flash drum 48 to line 66. The light liquid stream in the bottom line (62) can be further separated in the fractionation section (16).

The fractionation section 16 may comprise a stripping column 70 and a fractionation column 80. The light liquid stream in the bottom line 62 can be heated and fed to the stripping column 70. The liquid hydrocracking effluent, a light liquid stream, may be stripped by steam from line 72 to provide a hard end stream of hydrogen, hydrogen sulfide, steam, and other gases to overhead line 74. A portion of the rigid end-stream can be condensed and refluxed to the stripping column (70). The stripping column 70 may be operated at a bottom temperature of between about 232 ° C and 288 ° C (450 ° F to 550 ° F) and an overhead pressure of between about 690 and 1034 kPa (gauge) (100 to 150 psig). The hydrocracked bottoms stream in line 76 may be heated in a moving heater and fed to a fractionation column 80.

The fractionation column 80 also includes a non-conversion oil stream 88 in line 88 that may be suitable for further processing in an overhead naphtha stream of line 84, a diesel stream in line 86 from the side cut, The bottoms may be stripped of the hydrocracked bottoms with steam from the line 82 to provide a < Desc / Clms Page number 7 > The overhead naphtha stream in line 84 may require further processing before being blended in the gasoline pool. This will usually require catalyst modification to improve the octane number. The reforming catalysts will often require the overhead naphtha to be further desulfurized in a naphtha hydrotreater prior to reforming. In one embodiment, the hydrocracked naphtha can be desulfurized in an integral hydrotreater 92. It is also contemplated to obtain additional side cuts to provide a separate hard diesel or kerosene stream obtained above the heavy diesel stream obtained in line 86. A portion of the overhead naphtha stream in line 84 can be condensed and refluxed to fractionation column 80. The fractionation column 80 is maintained at a low temperature of 288 캜 to 385 캜 (550 캜 to 725 캜), preferably between 315 캜 and 357 캜 (600 캜 to 675 캜), and at atmospheric pressure or atmospheric pressure Lt; / RTI > Some of the hydrocracked precipitate may be reboiled instead of using steam stripping and returned to the fractionation column 80.

The diesel stream in line 86 can not meet the low sulfur diesel (LSD) specifications with a sulfur content of less than 50 wppm, the ULSD specification with a sulfur content of less than 10 wppm, or other specifications, although the sulfur content is reduced. Thus, the diesel stream must be further finishing in the diesel hydrotreater unit 14.

The diesel stream in line 86 is fed to a second hydrogen split line 56 at a segment 54 of a second hydrogen split line 56 line to provide a hydrotreating feed stream 90, 2 hydrotreated hydrogen stream. The diesel stream in line 86 may also be mixed with a co-feed that is not shown. The hydrotreating feed stream 90 can be heat exchanged with the hydrotreating effluent in line 94 and can be further heated in the moving heater and directed to the hydrotreating reactor 92. As a result, the hydrotreating reactor is in downstream communication with the fractionation section 16, the compressed hydrogen line 52 and the hydrocracking reactor 36. In the hydrotreater reactor 92, the diesel stream is hydrotreated in the presence of a hydrotreated hydrogen stream and a hydrotreating catalyst to provide a hydrotreated effluent stream 94. In an embodiment, all of the hydrotreated hydrogen stream is provided from the compressed hydrogen stream in line 52 via second hydrogen split line 56.

The hydrotreating reactor 92 may include more than one vessel and a plurality of catalyst beds. The hydrotreating reactor 92 of Figure 1 has two beds in one reactor vessel. In the hydrotreating reactor, hydrocarbons with heteroatoms are further demetallized, desulfurized and denitrified. The hydrotreating reactor may also contain a hydrotreating catalyst suitable for saturation of aromatic compounds, hydrodewaxing and hydroisomerization.

If the hydrocracking reactor 36 operates as a moderate hydrocracking reactor, the hydrocracking reactor may operate to convert up to 20 to 60 volume percent of the feed above the diesel boiling range to a boiling product in the diesel boiling range. As a result, the hydrotreater reactor 92 must have a very low conversion rate and is primarily for desulfurization when integrated with the moderate hydrocracking reactor 36 to meet fuel specifications, such as ULSD requirements.

Hydrotreating is a process in which hydrogen gas is contacted with hydrocarbons in the presence of a suitable catalyst, which is predominantly active in the removal of sulfur, nitrogen and other heteroatoms such as metal from the hydrocarbon feedstock. In hydrotreating, hydrocarbons with double bonds and triple bonds can be saturated. Aromatic compounds can also be saturated. Some hydrotreating processes are specifically configured to saturate aromatics. The cloud point of the hydrotreated product can also be reduced. Suitable hydrotreating catalysts for use in the present invention are any known conventional hydrotreating catalysts and may be any known conventional hydrotreating catalysts having a surface area of at least one Group VIII metal, preferably iron, cobalt and nickel, Preferably cobalt and / or nickel, and at least one Group VI metal, preferably molybdenum and tungsten. Other suitable hydrotreating catalysts include zeolite catalysts as well as noble metal catalysts, the noble metals being selected from palladium and platinum. It is within the scope of the present invention that two or more types of hydrotreating catalysts are used in the same hydrotreating reactor 92. The Group VIII metal is typically present in an amount ranging from 2 to 20% by weight, preferably from 4 to 12% by weight. The Group VI metal will typically be present in an amount ranging from 1 to 25% by weight, preferably from 2 to 25% by weight.

Preferred hydrotreating reaction conditions are from 290 ° C (550 ° F) to 455 ° C (850 ° F), suitably at 316 ° C (600 ° F) for diesel feed in the case of a combination of hydrotreating catalysts or hydrotreating catalysts. (600 psig), preferably 6.2 MPa (900 psig) to 13.1 MPa (400 psig), at a temperature of 427 ° C (800 ° F), preferably between 343 ° C (650 ° F) and 399 ° C 1900 psig), a liquid hourly space velocity of the novel hydrocarbon feedstock of from 0.5 hr ^-1 to 4 hr ^-1 , preferably from 1.5 to 3.5 hr ^-1 , and from 168 to 1,011 Nm ³ / m ^{3 of} oil 6,000 scf / bbl), preferably 168 to 674 Nm ³ / m ³ oil (1,000 to 4,000 scf / bbl). Because the hydrotreating unit 14 is integrated with the hydrocracking unit 12, both units operate at the same pressure to form a normal pressure drop.

The hydrotreated effluent stream in line 94 may be heat exchanged with the hydrotreating feed stream in line 90. The hydrotreated effluent stream in line 94 is separated in a warm separator 96 to provide a vaporized hydrotreated effluent stream containing hydrogen to a warm separator overhead line 98 and a liquid hydrogen To provide a treated effluent stream. The hydrotreated effluent stream comprising hydrogen may be mixed with the hydrocracked effluent stream in line 38 before entering the cryogenic separator 40, possibly before cooling. The warming separator 96 may be operated at 149 ° C to 260 ° C (300 ° F to 500 ° F). The pressure of the warm separator 96 is a pressure just below the pressure of the hydrotreating reactor 96, which results in a pressure drop. The warming separator may be operated to obtain at least 90 wt% diesel, preferably at least 93 wt% diesel, in the liquid stream in line 100. The other hydrocarbons and all of the gas rises to the steam hydrotreated effluent stream in line 98 and the steam hydrotreated effluent stream is combined with the hydrocracked effluent in line 38 and is first heated with the hydrocracked effluent and then passed through a low temperature separator Lt; RTI ID = 0.0 > 40 < / RTI > As a result, the cryogenic separator 40 and, hence, the recycle gas compressor 50 are communicated downstream with the heat separator overhead line 98. Thus, the recycle gas loops from both the hydrocracking section 12 and the hydrotreating section 14 share the same recycle gas compressor 50. Furthermore, at least a portion of the hydrotreated effluent stream in the hydrotreating effluent line 94, which contains hydrocarbons that are harder than diesel in the hydrogen and warm separator overhead line 98 and is provided to the warm separator overhead stream, Lt; RTI ID = 0.0 > 38 < / RTI >

The liquid hydrotreated effluent stream in line 100 can be fractionated in the hydrotreating stripper column 102. In one embodiment, fractionation of the liquid hydrotreating effluent stream in line 100 can include flashing the liquid hydrotreated effluent stream in warmed flash drum 104, which is supplied to warming separator 96 and But can be operated at the same temperature, but at a lower pressure of 1.4 MPa to 3.1 MPa (gauge) (200 to 450 psig). The warmed flash overhead stream in the warmed flash overhead line 106 can be coupled to the liquid hydrocracked effluent stream in the low temperature separator bottom line 44 and further fractionated with the liquid hydrocracked effluent stream. As a result, a warmed flash overhead stream within the warmed flash overhead line 106 is provided, and at least a portion of the hydrotreated effluent stream in line 94 containing hydrogen comprises liquid hydrocracking effluent in the low temperature separator bottom line 44 May be mixed with at least a portion of the hydrocracked effluent stream in line 38, which is provided to the stream.

The warmed flash bottom stream in line 108 can be heated and fed to the stripper column 102. The warmed flash precipitate may be stripped in stripper column 102 by steam from line 110 to provide naphtha and a hard end stream to overhead line 112. The naphtha and hard end stream in line 112 may be fed to stripping column 70 at the height above the feed point of the light liquid stream in fractionation section 16 and particularly in line 62. A product diesel stream comprising less than 50 wppm sulfur, preferably less than 10 wppm sulfur is recovered in the bottom line 114, including less than 50 wppm sulfur is qualified as an LSD, less than 10 wppm sulfur Is qualified as a ULSD. It is also contemplated that the stripper column 102 may be operated as a fractionation column having a reboiler instead of stripping steam.

By operating the warming separator 96 at an elevated temperature to remove most of the hydrocarbons that are harder than the diesel, the hydrotreating stripping column 102 can be operated more simply because the hydrotreating stripping This is because the column does not need to separate the naphtha from the harder components and the naphtha to be separated from the diesel is very small. Moreover, the warming separator 96 shares the possible hydrocracking reactor 36 with the cold separator 40, and the heat useful for fractionation in the stripper column 102 is retained in the hydrotreating liquid effluent.

2 illustrates an embodiment of a method and apparatus 8 utilizing a hot separator 120 to initially separate the hydrocracked effluent in line 38 '. The multiple elements of FIG. 2 have the same configuration as FIG. 1 And are given the same reference numerals. Elements of FIG. 2 corresponding to the elements of FIG. 1 but having different configurations are the same as in FIG. 1, but are given reference numerals with a prime symbol (').

The hot separator 120 in the hydrocracking section 12 'communicates downstream with the hydrocracking reactor 36 and provides a stream of vapor hydrocarbons to the overhead line 122 and a stream of liquid hydrocarbons to the bottom line 124 do. The hot separator 120 operates at a temperature of 177 ° C to 343 ° C (350 ° F to 650 ° F), preferably at a temperature of 232 ° C to 288 ° C (450 ° F to 550 ° F). The hot separator may operate at a slightly lower pressure than the hydrocracking reactor 36, resulting in a pressure drop. The vapor hydrocarbon stream in line 122 may be combined by the vapor hydrotreating effluent stream in line 98 'from hydrotreating section 14' and mixed and transported together in line 126. The mixed stream in line 126 may be cooled before entering cryogenic separator 40. As a result, the steam hydrocracked effluent is separated with the steam hydrotreated effluent stream in the cryogenic separator 40 to form a vapor hydrocracked effluent containing hydrogen in line 42 and liquid hydrocracking The effluent may be treated as described above with respect to FIG. The cryogenic separator 40 is in communication with the overhead line 122 of the hot separator 120 and the overhead line 98 'of the warm separator 96 downstream.

The liquid hydrocarbon stream in bottom line 124 can be fractionated in fractionation section 16 '. In one aspect, the liquid hydrocarbon stream in line 124 can be flushed in hot flash drum 130 to provide a hard end stream to overhead line 132 and a heavy liquid stream to bottom line 134 have. The hot flash drum 130 may be operated at the same temperature as the hot separator 120, but at a lower pressure of 1.4 MPa to 3.1 MPa (gauge) (200 to 450 psig). The heavy liquid stream in the bottom line 134 can be further discriminated in the fractionation section 16 '. In one aspect, the heavy liquid stream in line 134 can be introduced into stripping column 70 at a lower elevation than the light liquid stream feed point in line 62.

The remainder of the embodiment of FIG. 2 may be the same as that described with reference to FIG. 1, except as noted above.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention are described herein, including the best mode known to the inventors for practicing the present invention. It should be understood that the illustrated embodiments are merely illustrative and should not be taken as limiting the scope of the invention.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The foregoing preferred specific embodiments are accordingly to be considered exemplary only and are not intended to limit the remainder of this disclosure in any way.

In the foregoing, all temperatures are stated in degrees Celsius, unless otherwise indicated, and all parts and percentages are by weight. The pressure is given at the outlet of the vessel, especially at the outlet of the vessel with the plurality of outlets.

From the foregoing description, those skilled in the art will readily be able to acquire essential features of the present invention, and various modifications and alterations of the present invention can be made without departing from the spirit and scope of the present invention.

Claims (10)

As a diesel production process for producing diesel from a hydrocarbon stream.
Compressing the supplemental hydrogen stream in the compressor to provide a make-up hydrogen stream;
Obtaining a hydrocracking hydrogen stream from the compressed supplemental hydrogen stream;
Hydrocracking a hydrocarbon stream in the presence of a hydrocracked hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream;
Separating the hydrocracking effluent stream into a hydrocracking effluent stream comprising hydrogen and a liquid hydrocracking effluent stream;
Compressing the vapor hydrocracking effluent stream to provide a compressed hydrogen stream;
Obtaining a hydrotreating hydrogen stream from the compressed hydrogen stream;
Fractionating a liquid hydrocracking effluent stream to provide a diesel stream; And
Hydrotreating the diesel stream in the presence of a hydrotreated hydrogen stream and a hydrotreating catalyst to provide a hydrotreated effluent stream,
≪ / RTI > 2. The method of claim 1, wherein after the step of hydrotreating the diesel stream, the hydrotreating effluent stream is separated into a hydrotreated effluent stream comprising hydrogen and a liquid hydrotreated effluent stream, Further comprising mixing the stream with a hydrocracked effluent stream. 2. The method of claim 1, wherein obtaining the hydrocracked hydrogen stream from the compressed supplemental hydrogen stream comprises:
Compressing the compressed supplemental hydrogen stream in a recycle gas compressor to provide a compressed hydrogen stream; And
Obtaining a hydrocracked hydrogen stream from the compressed hydrogen stream
≪ / RTI > The process of claim 1, wherein separating the hydrocracking effluent stream into a hydro-hydrocracked effluent stream comprising hydrogen and a liquid hydrocracking effluent stream comprises:
Separating the hydrocracked effluent stream into a vapor hydrocarbon stream and a liquid hydrocarbon stream; And
Separating the steam hydrocarbon stream to provide a vapor hydrocracking effluent stream comprising the hydrogen and the liquid hydrocracking effluent stream
≪ / RTI > The method of claim 1, further comprising the step of hydrotreating the diesel stream, followed by fractionating a liquid hydrotreated effluent stream comprising at least 90% by weight diesel to provide an ultra low sulfur diesel stream ≪ / RTI > In a diesel producing apparatus for producing diesel,
A hydrogenolysis reactor in communication with the at least one compressor on the hydrocarbon feed line and the supplemental hydrogen line, for hydrocracking the hydrocarbon stream to lower boiling point hydrocarbons;
A recycle gas compressor for compressing a vapor hydrocracking effluent stream comprising hydrogen to provide a recycle hydrogen stream to a recycle hydrogen line, the recycle hydrogen compressor comprising: a first recycle hydrogen line and a second recycle line, Providing a hydrogen split line, said first recycle hydrogen split line providing recycled hydrogen in upstream communication with said hydrocracking reactor; And
A second recycle hydrogen splitting line and a hydrocracking reactor, said hydrotreating reactor for hydrotreating the diesel stream to produce a low sulfur diesel,
And a diesel engine. 7. The diesel manufacturing apparatus of claim 6, wherein the recycle gas compressor is in communication with the supplemental hydrogen line. 7. The diesel production apparatus of claim 6, further comprising a fractionation section in communication with the hydrocracking reactor for fractionating the hydrocracked effluent stream to produce a diesel stream, wherein the hydrotreating reactor is in communication with the fractionation section. 7. The process of claim 6, further comprising the steps of: contacting a hydrotreating effluent stream with a warm separator to separate the hydrotreated effluent stream comprising overhead line hydrogen and the bottom hydrotreated effluent stream, Wherein the recycle gas compressor is in communication with the overhead line. 10. The diesel manufacturing apparatus of claim 9, further comprising a fractionation column in communication with the bottom line of the warm separator, for fractionating the liquid hydrotreated effluent stream to provide a low sulfur diesel stream.

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