RU2540081C1 - Method and plant for hydraulic treatment of two flows - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: proposed process comprises compression of boost hydrogen in first compressor to get first flow of compressed boost hydrogen. First flow of compressed boost hydrogen is compressed in second compressor to get second flow of compressed boost hydrogen. Said second flow of compressed boost hydrogen is separated as second flow of compressed boost hydrogen for hydraulic treatment. First flow of hydrocarbons is processed over first flow for hydraulic processing including second flow of compressed boost hydrogen and first hydraulic processing catalyst to get first effluent flow of hydroprocessing products. Second flow of hydrocarbons is processed over second flow for hydraulic processing including first flow of compressed boost hydrogen and first hydraulic processing catalyst to get second effluent flow of hydroprocessing products. Said second effluent flow of hydroprocessing products is separated to get vaporous second effluent flow of hydroprocessing products. Said vaporous second flow is added to said boost hydrogen flow upstream of said first compressor.

EFFECT: perfected feed of hydrogen to separate process units.

9 cl, 2 dwg

Description

This application claims priority for applications for US patent 13/076647, 13/076658, 13/076670 and 13/076680, the filing date of all these applications is March 31, 2011.

FIELD OF THE INVENTION

The invention relates to the hydroprocessing of two hydrocarbon streams at different pressures.

State of the art

Hydrocracking refers to a process in which hydrocarbons are cracked in the presence of hydrogen and a catalyst to produce lower molecular weight hydrocarbons. Depending on the desired capacity, the hydrocracking zone may contain one or more layers of the same catalyst or different catalysts. Hydrocracking is a process used to crack hydrocarbon feedstocks, such as vacuum gas oil (VGO), to produce diesel fuel, including kerosene, and fuel for gasoline engines.

Usually, upstream from a catalytic cracking unit in a fluidized bed (FCC) or other process unit, soft hydrocracking is carried out to improve the quality of the crude oil, which can be sent to a downstream unit, and at the same time, part of the feed is converted from obtaining lighter products such as diesel fuel.

As the global demand for diesel fuel is increasing relative to gasoline fuel, mild hydrocracking is being considered with the aim of shifting the product output towards diesel fuel to the detriment of gasoline output. Mild hydrocracking can be carried out with less stringency compared to hydrocracking carried out with partial or complete conversion of hydrocarbons in order to align diesel fuel production with the capabilities of a fluidized-bed cracking unit, which is mainly used for receiving naphtha. Hydrocracking with partial or full conversion of hydrocarbons is used to produce diesel fuel with a lower yield of unconverted oil, which can be sent to the downstream unit.

For environmental reasons and according to the newly legalized rules and regulations, commercial diesel fuel must meet ever lower pollution limits with substances such as sulfur and nitrogen. New regulations require essentially complete removal of sulfur from diesel fuel. For example, a requirement for ultra-low sulfur diesel fuels is typically a sulfur content of less than 10 wppm (parts by weight per million).

The combination of hydroprocessing units into a single complex can meet such situations in which one unit operates at a higher pressure than another. For example, a hydrocracking unit operates at a higher pressure than a hydrotreating unit. Hydrogen must be supplied at various pressures. Excess hydrogen is recirculated by a gas recirculation compressor designed specifically for each hydroprocessing unit.

Therefore, there is a continuing need for improved methods for the production of diesel fuel from hydrocarbon feedstocks in greater quantities than the amount of gasoline produced. Such methods should ensure that diesel meets the increasingly stringent product requirements. There is also a need for improved methods of supplying hydrogen to individual process plants at various pressures.

Disclosure of invention

In one embodiment related to the method, the invention includes a method for producing diesel fuel from a hydrocarbon stream, comprising compressing a make-up hydrogen stream in a first compressor to produce a first compressed make-up hydrogen stream. The first part of the first compressed make-up hydrogen stream is compressed in a second compressor to produce a second compressed make-up hydrogen stream. The second part of the first stream of compressed make-up hydrogen is selected as a second hydrogen stream for hydroprocessing. The hydrocarbon stream is hydrocracked in the presence of a second stream of compressed make-up hydrogen and a hydrocracking catalyst to produce an output stream of hydrocracking products. The diesel stream is hydrotreated in the presence of a second hydrogen stream for hydrotreatment and a hydrotreatment catalyst to produce a second hydrotreatment product effluent. Finally, at least a portion of said first hydrotreatment product effluent is fractionated to produce a diesel fuel stream.

In another embodiment related to the method, the invention includes a method for producing diesel fuel from a hydrocarbon stream, comprising compressing a make-up hydrogen stream in a first compressor to produce a first compressed make-up hydrogen stream. The first part of the first compressed make-up hydrogen stream is compressed in a second compressor to produce a second compressed make-up hydrogen stream. The second part of the first stream of compressed make-up hydrogen is selected as a second hydrogen stream for hydroprocessing. The diesel fuel stream is hydrotreated in the presence of a second hydrogen stream for hydrotreatment and a hydrotreatment catalyst to produce a second hydrotreatment effluent stream. The hydrocarbon stream is hydrocracked in the presence of a first hydroprocessing hydrogen stream containing a second compressed make-up hydrogen stream and a hydrocracking catalyst to produce an effluent stream. At least a portion of said first hydrotreatment product effluent is fractionated to produce a diesel fuel stream. The first hydroprocessing effluent is separated and a vaporous first hydroprocessing effluent containing hydrogen is obtained. The vaporous first hydrotreatment product effluent is compressed to produce a recycle hydrogen stream. Finally, a recycle hydrogen stream is added to the first hydroprocessing hydrogen stream.

In accordance with another embodiment related to the method, the invention includes a method for producing diesel fuel from a hydrocarbon stream, comprising compressing a make-up hydrogen stream in a first compressor to produce a first compressed make-up hydrogen stream. The first part of the first compressed make-up hydrogen stream is compressed in a second compressor to produce a second compressed make-up hydrogen stream. The hydrocarbon stream is hydrocracked in the presence of a first hydroprocessing hydrogen stream containing a second compressed make-up hydrogen stream and a hydrocracking catalyst to produce a first hydroprocessing effluent. The second part of the first stream of compressed make-up hydrogen is selected as a second hydrogen stream for hydroprocessing. The diesel fuel stream is hydrotreated in the presence of a second hydrogen stream for hydrotreatment and a hydrotreatment catalyst to produce a second hydrotreatment effluent stream. At least a portion of said first hydroprocessing effluent is fractionated to produce a diesel stream. Finally, at least a portion of the second hydrotreatment effluent is fractionated to produce low sulfur diesel fuel.

In one embodiment related to the device, the invention includes a diesel fuel production apparatus comprising a make-up hydrogen pipe for transporting a make-up hydrogen stream; a first compressor that communicates with the make-up hydrogen pipeline and is designed to compress the make-up hydrogen stream to produce a first stream of compressed make-up hydrogen; a separation device in communication with the first compressor, which serves to separate the first stream of compressed make-up hydrogen into a first part transported through a first branch of the pipeline and a second part containing a second hydrogen stream for hydroprocessing transported through a second branch of the pipeline; moreover, the second compressor communicates with the first branch of the pipeline for compressing the first part of the first stream of compressed make-up hydrogen to obtain a second stream of compressed make-up hydrogen transported through the second pipe for compressed make-up hydrogen; a hydrocracking reactor in communication with the first branch of the pipeline and designed for hydrocracking a hydrocarbon stream to obtain a stream of diesel fuel; wherein the hydrotreating reactor communicates with the second branch of the pipeline and the hydrocracking reactor and serves for hydrotreating the flow of diesel fuel.

In another embodiment related to the device, the invention includes an installation for the production of diesel fuel comprising a make-up hydrogen pipe for transporting a make-up hydrogen stream; a first compressor that communicates with the make-up hydrogen pipeline and is designed to compress the make-up hydrogen stream to produce a first stream of compressed make-up hydrogen; a second compressor in communication with the first compressor for compressing a portion of the first compressed make-up hydrogen stream to produce a second compressed make-up hydrogen stream; a hydrocracking reactor in communication with a second compressor for hydrocracking a hydrocarbon stream to produce a diesel fuel stream; wherein the hydrotreating reactor communicates with the first compressor and the hydrocracking reactor and serves to hydrotreat the diesel fuel stream.

In a further embodiment related to the device, the invention includes a diesel fuel production apparatus comprising a make-up hydrogen pipe for transporting a make-up hydrogen stream; a first compressor that communicates with the make-up hydrogen pipeline and is designed to compress the make-up hydrogen stream to produce a first stream of compressed make-up hydrogen; a hydrotreating reactor in communication with a first compressor for hydroprocessing a diesel stream; a second compressor in communication with the first compressor for compressing a portion of the first compressed make-up hydrogen stream to produce a second compressed make-up hydrogen stream; a hydrocracking reactor in communication with a second compressor for hydrocracking a hydrocarbon stream to produce lower boiling hydrocarbons; a cold separator in communication with the hydrotreating reactor, designed to separate the second effluent of the hydroprocessing products to obtain a vaporous second effluent of the hydroprocessing products containing hydrogen transported through the head pipe, and a liquid second hydroprocessing product effluent discharged through the bottom pipe, the second compressor communicates with the main pipeline.

In another embodiment related to the method, the invention includes a method for hydrotreating two hydrocarbon streams, comprising compressing a make-up hydrogen stream in a first compressor to produce a first compressed make-up hydrogen stream. The first part of the first compressed make-up hydrogen stream is compressed in a second compressor to produce a second compressed make-up hydrogen stream. The second part of the first stream of compressed make-up hydrogen is selected as a second hydrogen stream for hydroprocessing. The first hydrocarbon stream is hydrotreated in the presence of a first hydrotreatment hydrogen stream comprising a second compressed make-up hydrogen stream and a first hydrotreatment catalyst to produce a first hydrotreatment effluent. The second hydrocarbon stream is hydrotreated in the presence of a second hydrotreatment stream containing a first compressed make-up hydrogen stream and a second hydrotreatment catalyst to produce a second hydrotreatment effluent. Said second hydroprocessing effluent is separated and a vaporous second hydroprocessing effluent is obtained. Finally, the resulting vaporous second effluent from the hydrotreatment product is added to the make-up hydrogen stream upstream of the second compressor.

According to another embodiment related to the method, the invention includes a method for hydrotreating two hydrocarbon streams, comprising compressing a make-up hydrogen stream in a first compressor to produce a first compressed make-up hydrogen stream. The first part of the first compressed make-up hydrogen stream is compressed in a second compressor to produce a second compressed make-up hydrogen stream. The second part of the first stream of compressed make-up hydrogen is selected as a second hydrogen stream for hydroprocessing. The first hydrocarbon stream is hydrotreated in the presence of a first hydrotreatment stream containing a second compressed make-up hydrogen stream and a hydrocracking catalyst to produce a first hydrotreatment product stream. The second hydrocarbon stream is hydrotreated in the presence of a second hydrogen stream for hydrotreatment and a hydrotreatment catalyst to produce a second hydrotreatment effluent. Said second hydroprocessing effluent is separated to produce a vaporous second hydroprocessing effluent. Finally, the resulting vaporous second effluent from the hydrotreatment product is added to the first part of the first compressed hydrogen feed stream.

According to another embodiment related to the method, the invention includes a method for hydrotreating two hydrocarbon streams, comprising compressing a make-up hydrogen stream in a first compressor to produce a first compressed make-up hydrogen stream. The first part of the first compressed make-up hydrogen stream is compressed in a second compressor to produce a second compressed make-up hydrogen stream. The second part of the first compressed make-up hydrogen stream is compressed as a second hydroprocessing hydrogen stream. The first hydrocarbon stream is hydrocracked in the presence of a first hydrotreatment hydrogen stream containing a second compressed make-up hydrogen stream and a hydrocracking catalyst to produce a first hydrotreatment product stream. The second hydrocarbon stream is hydrotreated in the presence of a second hydrogen stream for hydrotreatment and a hydrotreatment catalyst to produce a second hydrotreatment effluent. Said second hydroprocessing effluent is separated to produce a vaporous second hydroprocessing effluent. The resulting vaporous second effluent from the hydrotreatment product is added to the make-up hydrogen stream upstream of the first compressor.

In another embodiment related to the device, the invention includes an apparatus for hydrotreating two hydrocarbon streams, comprising a make-up hydrogen pipe for transporting a make-up hydrogen stream; a first compressor that communicates with the make-up hydrogen pipeline and is designed to compress the make-up hydrogen stream to produce a first stream of compressed make-up hydrogen; a separation device in communication with the first compressor, which serves to separate the first stream of compressed make-up hydrogen into a first part transported through a first branch of the pipeline and a second part containing a second hydrogen stream for hydroprocessing transported through a second branch of the pipeline; a second compressor in communication with the first branch of the pipeline, which serves to compress the first part of the first stream of compressed make-up hydrogen to obtain a second stream of compressed make-up hydrogen transported through the second pipe for compressed make-up hydrogen; a first hydroprocessing reactor in communication with the first branch of the pipeline and designed for hydroprocessing the first hydrocarbon stream; a second hydroprocessing reactor, which communicates with the second branch of the pipeline and serves to hydroprocess a second hydrocarbon stream; a separator in communication with the second hydroprocessing reactor and designed to separate the second effluent of the hydroprocessing products to produce a vaporous second effluent of the hydroprocessing products containing hydrogen transported in the head pipe, the second compressor communicating with the head pipe.

In another embodiment related to the device, the invention further includes a unit for hydrotreating two hydrocarbon streams, comprising a make-up hydrogen pipe for transporting a make-up hydrogen stream; a first compressor that communicates with the make-up hydrogen pipeline and is designed to compress the make-up hydrogen stream to produce a first stream of compressed make-up hydrogen; a separation device in communication with the first compressor and designed to separate the first stream of compressed make-up hydrogen into a first part transported through a first branch of the pipeline and a second part containing a second hydrogen stream for hydroprocessing transported through a second branch of the pipeline; a second compressor, which communicates with the first branch of the pipeline and serves to compress the first part of the first stream of compressed make-up hydrogen to obtain a second stream of compressed make-up hydrogen transported through the second pipe for compressed make-up hydrogen; a hydrocracking reactor in communication with the first branch of the pipeline and used to conduct hydrocracking of the first hydrocarbon stream to produce lower boiling hydrocarbons; a hydrotreating reactor communicating with a second branch of the pipeline and serving to hydrotreat a second hydrocarbon stream; a separator in communication with the hydrotreating reactor and designed to separate the second effluent of the hydroprocessing products to obtain a vaporous second effluent of the hydroprocessing products containing hydrogen transported in the head pipe; wherein the second compressor communicates with the main pipeline at the junction at the first branch of the pipeline.

According to another embodiment related to the device, the invention includes an installation for hydrotreating two hydrocarbon streams, comprising a make-up hydrogen pipeline for transporting a make-up hydrogen stream; a first compressor that communicates with the make-up hydrogen pipeline and is designed to compress the make-up hydrogen stream to produce a first stream of compressed make-up hydrogen; a separation device in communication with the first compressor and serving to separate the first stream of compressed make-up hydrogen into a first part transported through a first branch of the pipeline and a second part containing a second hydrogen stream for hydroprocessing transported through a second branch of the pipeline; a second compressor in communication with the first branch of the pipeline and designed to compress the first part of the first stream of compressed make-up hydrogen to obtain a second stream of compressed make-up hydrogen transported through the second pipe for compressed make-up hydrogen; a hydrocracking reactor in communication with the first branch of the pipeline and used to conduct hydrocracking of the first hydrocarbon stream to produce lower boiling hydrocarbons; a hydrotreating reactor, which communicates with a second branch of the pipeline and serves to hydrotreat a second hydrocarbon stream; a separator in communication with the hydrotreating reactor and designed to separate the second effluent of the hydroprocessing products to obtain a vaporous second effluent of the hydroprocessing products containing hydrogen transported in the head pipe; wherein the first compressor communicates with the lead pipeline at its junction with the make-up hydrogen pipeline.

Brief Description of the Drawings

Figure 1 is a simplified diagram of a process for implementing the present invention.

Figure 2 is a simplified process diagram for an alternative embodiment of the present invention.

Definitions

The term "message" means that during the operation of the installation between the listed components a material flow is provided.

The term “downstream message” means that during operation of the installation, at least a portion of the material passing to the interaction object may, when communicating downstream, pass from the interaction subject with which the said object is communicating.

The term “upstream message” means that during operation of the installation, at least a portion of the material passing from the subject of interaction can, when communicating upstream, pass to the object of interaction with which the specified subject is communicating.

The term "column" means a distillation column or columns designed to separate one or more components with different volatilities. Unless otherwise specified, each column at the top contains a condenser that is used to condense and return part of the top (head) stream back to the top of the column, and a boiler at the bottom of the column to evaporate and direct part of the bottom (bottom) stream back to the bottom the columns. The feed to the columns may be preheated. The pressure at the top of the column is the head vapor pressure at the vapor outlet of the column. The bottom temperature is the outlet temperature of the bottom liquid. Pipelines for the upper (head) stream and pipelines for the lower (bottom) stream belong to the network of pipelines passing from the column downstream from the place of reflux or return of the boiling stream to the column.

As used herein, the term “true boiling point” (TBP) refers to a test method for determining the boiling point of a material that complies with ASTM D-2892 for the production of liquefied gas, distillate fractions and a residue of standard quality, from which analytical data can be obtained, and determining the yield of the above fractions by weight and volume. According to the results of these tests, a temperature graph is obtained depending on the distillation mass (in mass%), based on the calculation of fifteen theoretical plates in a column with a reflux ratio of 5: 1.

As used herein, the term “conversion” means the conversion of a feed into a material that boils at a temperature in the range of the boiling point of diesel fuel or at lower temperatures. The boiling range of the fraction from the boiling range of diesel fuel is in the range from 343 ° to 399 ° C (from 650 ° to 750 ° F) using the method of determining the fractional composition from the “true boiling points”.

The term “diesel boiling range” as used herein refers to hydrocarbons boiling in the range of 132 ° to 399 ° C. (270 ° to 750 ° F.), and a method for determining the fractional composition from “true boiling temperatures” is used to determine this interval.

DETAILED DESCRIPTION OF THE INVENTION

Two-stage hydroprocessing units often operate at different pressures, and each of the two hydroprocessing units contains its own dedicated recycle gas compressor. If one of the hydrotreatment plants is a typical hydrotreatment plant, it contains a recycle gas compressor that removes its gas from the cold separator downstream of the hydrotreatment reactor and returns hydrogen-rich gas to the inlet of the hydrotreatment reactor. Typically, both hydroprocessing units require a feed gas stream.

A recycle gas compressor in one hydroprocessing unit can be eliminated by taking gas from the make-up gas compression system used in the first hydroprocessing unit, which may be a hydrocracking unit. The make-up gas stream may be diverted from the outlet of the first compression stage and return upstream or downstream of the first compression stage. The second compression stage, located downstream of the first compression stage, can increase the pressure of the make-up gas to a higher pressure necessary for the operation of the first hydroprocessing unit. Only part of the make-up hydrogen is sent to a second hydrotreatment unit, which may be a hydrotreatment unit.

Mild hydrocracking reactors operate at low stiffness conditions and, therefore, provide a low degree of conversion. Diesel fuel produced as a result of mild hydrocracking is of insufficient quality to satisfy the existing technical requirements for fuel, in particular with regard to sulfur content. In this regard, diesel fuel produced by soft cracking can be processed in a hydrotreatment unit so that it can be mixed into the finished diesel fuel.

In many cases, it seems attractive to combine a mild hydrocracker and a hydrotreatment unit to reduce capital and operating costs.

Figure 1 presents the device and method 8 for the production of diesel fuel, which include a compressor section 10, a first installation 12 for hydroprocessing, a second installation 14 for hydroprocessing and section 16 fractionation. The first hydrocarbon feed 38 may be fed to the first hydroprocessing unit 12 and converted to low boiling hydrocarbons such as diesel fuel. The effluent from the hydroprocessing unit 12 can be fractionated at the fractionation section 16, and the fractionation product can be sent to the second hydroprocessing unit 14. The first hydroprocessing unit 12 operates at a higher pressure than the second hydroprocessing unit 14.

The make-up hydrogen stream through the make-up hydrogen line 20 is supplied to the first compressor 22 to increase the pressure of the make-up hydrogen stream and obtain a first compressed make-up hydrogen stream in the line 24. The make-up hydrogen stream in the line 20 may first be combined with a vaporous second product effluent transported by pipeline 98, at the point 25 of the connection of these pipelines with obtaining a combined stream in the pipe 26 upstream from the first compressor 22. Combined nenny stream in line 26 may then be compressed in the first compressor 22 to produce a first stream of the compressed makeup hydrogen to the conduit 24 for compressed makeup hydrogen. The first compressor may be a series of series-connected compressors.

A separation device 27 mounted on the compressed hydrogen make-up pipe 24 allows the first part of the compressed hydrogen make-up to enter the first branch 28 of the pipeline and the second part of the compressed make-up hydrogen to the second branch 30 of the pipeline. The second part of the compressed make-up hydrogen, passing through the second branch 30 of the pipeline, is sent to the second installation 14 hydroprocessing.

The first part of the compressed make-up hydrogen passing through the first branch of the pipeline 28 may be subjected to additional compression in the second compressor 32, which may be a series of series-connected compressors, to obtain a second compressed make-up stream in the pipeline 34. The second compressed make-up stream in conduit 34 can be combined with a recycle hydrogen stream transported through conduit 56 to form a first hydroprocessing hydrogen stream in conduit 36. The first hydroprocessing unit 12 operates at a higher pressure than the second hydroprocessing unit 14.

The first hydroprocessing hydrogen stream transported through conduit 36, which is sampled from the second compressed make-up hydrogen stream, can be combined with the first hydrocarbon feed stream passing through conduit 38 to produce a first hydroprocessing feedstock conveyed through conduit 40.

The hydrocarbon feed stream is introduced into the pipeline 38, for example, through an intermediate equalization tank. In one aspect, the method and apparatus described herein are particularly effective for hydrotreating a hydrocarbon feedstock. Examples of such hydrocarbon feedstocks include hydrocarbon-containing streams containing components boiling at temperatures above 288 ° C (550 ° F), such as atmospheric gas oils, vacuum gas oil (VGO), de-asphalted residues of vacuum distillation and atmospheric distillation, coking distillates, direct distillates distillations, solvent-asphalted oils, pyrolysis oils, high-boiling synthetic oils, recycle gas oils, petroleum cracking oils, catalytic cracking distillates, etc. approved. This hydrocarbon feed may contain from 0.1 to 4 wt.% Sulfur.

A suitable hydrocarbon feed is VGO or another suitable hydrocarbon fraction containing at least 50 wt.% And, as a rule, at least 75 wt.% Of components boiling at temperatures above 399 ° C (750 ° F). A typical VGO typically has a boiling point in the range of 315 ° C (600 ° F) to 565 ° C (1050 ° F).

The first hydroprocessing reactor 42 may be in downstream communication with one or more compressors 22 and 32 installed on the make-up hydrogen pipe line 20, with a first hydrocarbon feed pipe 38 and with a first branch pipe 28. The first hydroprocessing feed stream can exchange heat with the first hydroprocessing product effluent passing through conduit 44 and is further heated in a fire heater before entering the first hydroprocessing reactor 42 to hydroprocess the first hydrocarbon stream. The first hydroprocessing reactor 42 may comprise one or more vessels, a plurality of catalyst beds in each vessel, and various combinations of a hydrotreating catalyst and a hydrocracking catalyst in one or more vessels.

The hydroprocessing carried out in the first hydroprocessing reactor 42 may be hydrocracking. In one aspect, the first hydroprocessing unit may be a hydrocracking unit 12, in which case the first hydroprocessing hydrogen stream is a hydrocracking hydrogen stream in conduit 36, the first hydroprocessing reactor 42 is a hydrocracking reactor, which is downstream of the first branch 28 of the pipeline, and the flow of raw materials in the pipeline 40 is a flow of raw materials for hydrocracking.

Hydrocracking refers to a process in which hydrocarbons are cracked in the presence of hydrogen to hydrocarbons of lower molecular weight. In some aspects, the hydrocracking reaction provides a total hydrocarbon feed conversion of at least 20 volume. % and, as a rule, more than 60 volume. % to obtain products boiling at temperatures below the boiling range of diesel fractions. The hydrocracking reactor 42 may operate with a partial conversion of more than 50 volume. %, or with a deep conversion of at least 90 volume. % of raw materials, based on the full conversion. To obtain the maximum amount of diesel fuel, deep conversion is effective. The first vessel or bed in the hydrocracking reactor 42 may comprise a hydrotreating catalyst for the purpose of demetallization, desulfurization or de-nitration of the hydrocracking feed.

Hydrocracking reactor 42 may operate under mild hydrocracking conditions. Under conditions of mild hydrocracking, the selective conversion of raw materials to heavy products, such as diesel fuel and kerosene, with a low yield of lighter hydrocarbons, such as naphtha and gas, occurs. The pressure is also chosen moderate to limit the hydrogenation of bottoms to a level that is optimal for processing downstream. The conditions under which mild hydrocracking is carried out will provide a total conversion of hydrocarbon feed from 20 to 60 volume. %, preferably from 20 to 50 volume. % to obtain products boiling at temperatures below the boiling range of diesel fractions. When the reactor is operated in soft hydrocracking, the hydrotreating catalyst plays exactly the same or greater role in conversion than the hydrocracking catalyst. The conversion taking place on the hydrotreating catalyst can be a significant part of the overall conversion. If the first hydroprocessing reactor 42 is designed to carry out mild hydrocracking, it is contemplated that the mild hydrocracking reactor 42 can be fully loaded with a hydrotreating catalyst or fully with a hydrocracking catalyst or with a number of layers of a hydrotreating catalyst and a hydrocracking catalyst. In the latter case, the hydrocracking catalyst beds can usually follow the hydrotreating catalyst beds. Most often, three layers of a hydrotreating catalyst may precede one or two layers of a hydrocracking catalyst, or there are no subsequent hydrocracking catalyst layers at all.

The first hydroprocessing reactor 42, shown in FIG. 1, contains four catalyst beds in a single reaction vessel. If soft hydrocracking is required, it is contemplated that the first three catalyst beds contain a hydrotreating catalyst, and the last catalyst bed contains a hydrocracking catalyst. If partial or deep hydrocracking is preferred, additional layers of the hydrocracking catalyst may be used with respect to the number of layers of the hydrocracking catalyst during mild hydrocracking.

According to one aspect, for example, if a balance of middle distillate and gasoline is preferred in the conversion product, mild hydrocracking can be carried out in the first hydroprocessing reactor 42 using a hydrocracking catalyst using amorphous aluminosilicate bases or low zeolite bases combined with one or more the amount of metal hydrogenating components of Group VIII or Group VIB (Periodic Table). According to another aspect, if the middle distillate in the conversion product is substantially preferable to gasoline, partial or deep conversion can be carried out in the first hydroprocessing reactor 42 using a catalyst that contains, in general, any crystalline zeolite base for cracking catalyst, onto which a metal hydrogenating component of Group VIII is deposited. Additional hydrogenation components may be selected from Group VIB to combine with the zeolite base.

The zeolite bases of a cracking catalyst are sometimes referred to as molecular sieves in the prior art, and are usually formed from silica, alumina and one or more exchange cations such as sodium, magnesium, calcium, rare earth metals, and the like. These bases, in addition, are characterized by the presence in the crystal structure of the pores of a relatively uniform diameter with a size ranging from 4 to 14 angstroms (10 ^-10 m). It is preferable to use zeolites having a relatively high molar ratio of silica / alumina in the range of 3 to 12. Suitable natural zeolites are, for example, mordenite, stilbit, heylandite, ferrierite, daciardite, chabazite, erionite and faujasite. Suitable synthetic zeolites include, for example, types B, X, Y and L of crystalline zeolites, for example, synthetic faujasite and mordenite. It is preferable to use zeolites whose crystals have a pore diameter in the range from 8 to 12 Angstroms (10 ^-10 m), wherein the silica / alumina molar ratio is from 4 to 6. A representative example of the preferred group zeolite is a synthetic molecular sieve of type Y.

Naturally occurring zeolites are usually in the sodium form, in the form of an alkaline earth metal, and in a mixed form. Synthetic zeolites are almost always prepared first in sodium form. In any case, for use as a cracking catalyst base, it is preferable that most or all of the monovalent metal sources of zeolite production be replaced by polyvalent metal ions and / or an ammonium salt, followed by heating to split the ammonium ions bound to the zeolite, leaving ions in their place hydrogen and / or ion-exchange sites, which would actually be decationized upon subsequent removal of water. Hydrogen or "decationized" type Y zeolites of this nature are described in more detail in patent document US 3130006.

Mixed polyvalent metal-hydrogen zeolites can be prepared by ion exchange, first with an ammonium salt, then partially by reverse exchange with a polyvalent 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 zeolites with an alkali metal. In one aspect, preferred bases for a cracking catalyst are those that are at least 10 percent, and preferably at least 20 percent, that are deficient in metal cation based on the initial ion exchange capacity. According to another aspect, a desirable and stable class of zeolites is one in which at least 20 percent 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, including Group VIB metals, such as molybdenum and tungsten, can also be used in combination with them. The amount of hydrogenation metal in the catalyst can vary widely. In the General case, any amount in the range from 0.05 to 30 wt.% Can be used. In the case of noble metals, it is usually preferable to use from 0.05 to 2 wt.%.

A preferred method of incorporating the hydrogenation metal is to contact the zeolite base 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, dried, tabletted with added lubricants, binders or similar substances, if necessary, and calcined in air at a temperature, for example, in the range from 371 ° C to 649 ° C ( 700 ° to 1200 ° F) for activating the catalyst and decomposing ammonium ions. Alternatively, the zeolite component can be tableted first, followed by the addition of a hydrogenating component and activation by calcination.

The aforementioned catalysts can be used in undiluted form, or the powdery zeolite catalyst can be mixed and tableted together with other relatively less active catalysts, diluents or binders, such as alumina, silica gel, aluminosilicate clogs, activated clays, and the like. in ratios ranging from 5 to 90 wt.%. These diluents may be used as such or may contain a small proportion of the added hydrogenation metal, such as a metal of Group VIB and / or Group VIII.

Hydrocracking catalysts promoted with an additional metal, which can also be used in the method according to the present invention, which involves, for example, the use of aluminophosphate molecular sieves, crystalline chromosilicates and other crystalline silicates. Crystalline chromosilicates are more fully described in patent document US 4363718.

In one approach, hydrocracking conditions may include temperatures from 290 ° C (550 ° F) to 468 ° C (875 ° F), preferably from 343 ° C (650 ° F) to 435 ° C (815 ° F), excess a pressure in the range of 3.5 MPa (500 psig) to 20.7 MPa (3000 psig), a fluid hourly space velocity (LHSV) of 1.0 to less than 2.5 hours ^-1, and a hydrogen circulation rate of 421 to 2527 normal m ³ / m ^{3 of} oil (from 2500 to 15000 standard cubic feet per barrel). If mild hydrocracking is desired, conditions may include temperatures from 315 ° C (600 ° F) to 441 ° C (825 ° F), overpressure in the range of 5.5 to 13.8 MPa (800 to 2000 psig), or more preferably from 6, 9 to 11.0 MPa (1000 to 1600 psig), a fluid hourly space velocity (LHSV) of from 0.5 to 2 h ^−1, and preferably from 0.7 to 1.5 h ⁻¹ , and the hydrogen circulation rate is from 421 to 1685 normal m ³ / m ^{3 of} oil (from 2500 to 10000 standard cubic feet per barrel).

The hydroprocessing carried out in the first hydroprocessing reactor 42 may be hydrotreating. Hydrotreating is a process in which a gas containing hydrogen is contacted with a hydrocarbon in the presence of suitable catalysts that are active mainly to remove heteroatoms such as sulfur, nitrogen and metals from the hydrocarbon feed. When hydrotreating, hydrocarbons with double and triple bonds can become saturated. Aromatic compounds may also be saturated. Some hydrotreating processes are specifically designed to saturate aromatic compounds.

Hydrocracking catalysts suitable for use in the present invention are any conventional conventional hydrotreating catalysts that include catalysts formed from at least one Group VIII metal; iron, cobalt and nickel, more preferably cobalt and / or nickel, are preferred at least one Group VI metal, preferably molybdenum and tungsten, on a carrier material with a large surface area, preferably alumina. Other suitable hydrotreating catalysts include zeolite catalysts as well as noble metal catalysts for which the noble metal is selected from palladium and platinum. Within the scope of the present invention, more than one type of hydrotreating catalyst in the same tank may be used in the second hydroprocessing reactor 42. Group VIII metal is usually in an amount of from 2 to 20 wt.%, Preferably in the range of from 4 to 12 wt.%. Group VI metal is usually in an amount of from 1 to 25 wt.%, Preferably from 2 to 25 wt.%.

Preferred hydrotreating conditions may include temperatures from 290 ° C (550 ° F) to 455 ° C (850 ° F), suitably from 316 ° C (600 ° F) to 427 ° C (800 ° F), and preferably from 343 ° C (650 ° F) to 399 ° C (750 ° F), a pressure in the range of 3.4 MPa (500 psig), preferably 4.1 MPa (600 psig) to 6.2 MPa (900 psig), hourly volumetric the rate of fresh hydrocarbon feeds is from 0.5 to 4 hours ^-1 , preferably from 1.5 to 3.5 hours ^-1 , the hydrogen circulation rate is from 168 to 1011 normal m3 / m3 of oil (from 1000 to 6000 standard cubic feet per barrel) preferably from 168 to 674 normal m ³ / m ^{3 of} oil (1000 to 4000 standard cubic feet per barrel), for raw materials containing diesel fuel, using a hydrotreating catalyst or a combination of hydrotreating catalysts.

The hydroprocessing carried out in the first hydroprocessing reactor 42 may be hydroisomerization. The hydroisomerization process may also include catalytic dewaxing. Hydroisomerization is a process in which, in one aspect, at least 10 percent, in another aspect, at least 50 percent and, in another aspect, 10 to 90 percent of the n-paraffins of the hydrocarbon feed are converted to isoparaffins efficiently to produce an effluent stream of products with at least one of a cloud point of 0 ° C (32 ° F) or less, a pour point of 0 ° C (32 ° F) or less, and / or a cold plug temperature of the filter of 0 ° C (32 ° F) or less.

Typically, hydroisomerization process conditions include temperatures from 260 ° C (500 ° F) to 371 ° C (700 ° F), pressures from 1.38 MPa (200 psig) to 8.27 MPa (1200 psig), hourly space velocity of fresh hydrocarbon feedstock from 0.1 to 10 h ^-1 , the hydrogen circulation rate from 168 to 1011 normal m ³ / m ^{3 of} oil (from 1000 to 6000 standard cubic feet per barrel). However, other conditions of the hydroisomerization process are also possible, depending on the quality of the feed and other factors.

Suitable hydroisomerization catalysts are any conventional conventional hydroisomerization catalysts. For example, suitable catalysts may include zeolite components, hydrogenation / dehydrogenation components, and / or acidic components. In some forms, the catalysts may include at least one Group VIII metal, such as a noble metal (i.e., platinum or palladium). In other forms, the catalyst may also include silicon alumina phosphate and / or zeolite aluminosilicate. Examples of suitable catalysts are described in patent documents US 5976351; US 4,960,504; US 4,788,378; US 4,683,214; US 4,501,926 and US 4,419,220. However, other isomerization catalysts may also be used depending on the composition of the feedstock, process parameters, desired performance, and other factors.

The first hydroprocessing effluent is exited from the first hydroprocessing reactor 42 through a pipe 44. If the first hydroprocessing reactor 42 is a hydrocracking reactor, the first hydroprocessing effluent in the pipe 44 is a hydrocracking effluent. The first effluent of the flexible products passing through conduit 44 exchanges heat with the first hydroprocessing feedstock conveyed through conduit 40 and, in one embodiment, may be cooled before entering the first cold separator 46. The first cold separator 46 communicates with the first reactor downstream 42 hydroprocessing. The first cold separator can operate at a temperature of 46 ° to 63 ° C (115 ° to 145 ° F) and at a pressure slightly lower than the pressure in the first hydroprocessing reactor 42, taking into account the pressure drop to maintain the flow of hydrogen and light gases contained in the overhead stream , and liquid, under normal conditions, hydrocarbons in the bottom stream. The first cold separator 46 provides a vaporous first hydroprocessing effluent stream containing hydrogen in the head pipe 48 and a liquid first hydroprocessing effluent in the bottom pipe 50. The first cold separator also has a sump for collecting the aqueous phase discharged through line 52.

The vaporous first hydroprocessing effluent, which may be the vaporous hydrocracking effluent transported through conduit 48, may be compressed into a recycle gas compressor 54 to produce a recycle hydrogen stream in conduit 56. The recycle gas compressor 54 may communicate with the first downstream a hydroprocessing reactor 42, which may be a hydrocracking reactor. The recycle gas compressor 54 can compress the vaporous first hydroprocessing hydrogen-containing effluent coming through line 48 to produce a recycle hydrogen stream and transport the compressed stream through line 56. The second compressed make-up hydrogen stream transported through line 34 is combined with recycle hydrogen flowing through conduit 56, which is a compressed vaporous first hydroprocessing effluent, for both baking obtain a first hydrogen stream for hydroprocessing the feed via conduit 36. Reactor 42 communicates hydrocracking downstream to the conduit 56 for recycle hydrogen through conduits 36 and 40.

As noted above, in one embodiment, the recycle hydrogen stream in conduit 56 can be combined with a second compressed make-up hydrogen stream transported through conduit 34 downstream of the recycle gas compressor 54. However, if the pressure of the recycle hydrogen stream in line 56 is too high to mix the make-up hydrogen stream thereto without adding additional compressors upstream of the second compressed make-up hydrogen line 34, a second compressed make-up hydrogen stream may be added to the vaporous effluent hydrocracking products in line 48 upstream of the recycle gas compressor 54. This can improve the performance of the recycle gas compressor 54 due to the greater amount of gas flow through.

At least a portion of the first hydrotreatment product effluent discharged through conduit 44 may be fractionated in a portion 16 that is downstream of the first hydroprocessing reactor 42 to produce a second hydrocarbon stream transported through conduit 86. In one aspect, the liquid first effluent the fiber treatment product stream, which may be a liquid hydrocracked product effluent transported through conduit 50, may be fractionated a fractionation portion 16. According to another aspect, the fractionation portion 16 may comprise a cold evaporation drum 58. The first liquid hydrocracked product effluent transported through line 50 can be rapidly vaporized in a cold evaporation drum 58, which can operate at the same temperature as the cold separator 46, but at a lower overpressure, in the range from 1.4 MPa to 3.1 MPa (200-450 psig) to obtain from the first liquid effluent stream a hydroprocessing product of a light liquid stream in the bottom pipe 62 and sweat eye of light fractions discharged through the head conduit 64. The water stream through line 52 from the settler of the cold separator can also be directed to the cold evaporation drum 58. The water stream remaining after rapid evaporation is discharged from the settler of the cold evaporator drum 58 through line 66. Light stream the liquid in the bottom pipe 62 may be further fractionated in the fractionation portion 16.

The fractionation section 16 may comprise a stripping column 70 and a fractionation column 80. The stream of light liquid in the bottom pipe 62 can be heated and sent to the stripper column 70. The stream of light liquid, which is the liquid first effluent of the hydroprocessing products, can be steamed using water vapor entering through the pipe 72, to obtain a stream of light fractions including hydrogen, hydrogen sulfide, water vapor and other gases discharged through the head pipe 74. Part of the stream of light fractions can be condensed and returned as reflux to the stripping column 70. Opa Column 70 can operate at a bottoms temperature in the range of 232 ° to 288 ° C (450 ° to 550 ° F) and an overpressure of gases discharged from the top of the column in the range of 690 to 1034 kPa (100 to 150 psig ) The hydroprocessing bottom stream passing through conduit 76 can be heated in a fire heater and sent to fractionation column 80. A portion of the hydroprocessing bottom stream passing through conduit 76 can be boiled and returned to the stripping column 70 instead of using steam for steaming.

The fractionation column 80 may also steam off the bottom stream after hydrocracking using steam entering through line 82 to produce a naphtha overhead stream discharged through line 84, a diesel fuel stream discharged through line 86 as a side fraction, and discharged through line 88 crude oil, which may be suitable for further processing, for example, in a catalytic cracking unit in a fluidized bed. For the head naphtha stream discharged through line 84, it may be necessary to carry out additional processing before mixing in the gasoline mixing park. Typically, catalytic reforming is necessary to increase the octane rating of gasoline. For catalytic reforming it is often necessary that before it is carried out, the naphtha withdrawn from the top of the column is desulfurized in a naphtha hydrotreatment unit. In one aspect, the hydrocracked naphtha may be desulfurized in an integrated hydrotreatment unit. It is contemplated that the additional side fraction may be selected so as to provide a separate stream of light diesel fuel or kerosene taken upstream from the heavy diesel fuel stream withdrawn through conduit 86. A portion of the naphtha overhead stream discharged through conduit 84 may be condensed and returned as reflux to fractionation column 80. The fractionation column 80 may operate at a bottoms temperature in the range of 288 ° to 385 ° C (550 ° to 725 ° F), preferably 315 ° to 357 ° C (600 ° to 675 ° F) and at a pressure equal to or close to atmospheric. A portion of the bottom hydrocracking product can be boiled and returned to the fractionation column 80 instead of using steam for steaming.

Sulfur content may be reduced in the diesel stream discharged through line 86, but it does not meet the technical requirement of low sulfur content in diesel fuel (LSD), which is less than 50 wppm sulfur, the ULSD requirement (ultra low sulfur content in diesel fuel), which meets a sulfur content of less than 10 wppm, or other regulations. Therefore, the fuel can be further refined in the second hydrotreatment unit 14, which may be a hydrotreatment unit 14. Accordingly, the diesel fuel stream in conduit 86 may be a second hydrocarbon stream. The second hydrocarbon stream may have a lower average boiling point than the first hydrocarbon stream.

The second hydrocarbon stream transported through line 86 can be combined with a second hydroprocessing hydrogen stream comprising a second portion of a first compressed make-up hydrogen stream coming from the first branch 30 of the pipeline to produce a second hydroprocessing feed stream 90. The second hydrocarbon stream transported through line 86 can also be mixed with a co-feed, which is not shown. The second hydroprocessing feed stream 90 can exchange heat with a second hydroprocessing effluent transported via line 94, then can be heated in a fire heater and sent to a second hydroprocessing reactor 92.

Accordingly, the second hydroprocessing reactor 92 downstream communicates with the fractionation portion 16, separation device 27, and the first hydroprocessing reactor 42. In the second hydrotreating reactor 92, a second hydrocarbon stream, which may be a diesel fuel stream, is hydrotreated in the presence of a second hydrotreatment hydrogen stream and a second hydrotreatment catalyst to produce a second hydrotreatment effluent 94.

The second hydroprocessing reactor 92 may comprise more than one tank and multiple catalyst beds. The second hydroprocessing reactor 92 shown in FIG. 1 contains two catalyst beds in one reaction vessel. The second hydroprocessing reactor 92 may operate as a hydrocracking reactor, a hydrotreating reactor, or a hydroisomerization reactor, into which a suitable catalyst is charged, as described above with respect to the first hydroprocessing reactor 42. The second hydroprocessing reactor 92 downstream may be in communication with a second branch pipe 30 and a first hydroprocessing reactor 42, which may be a hydrocracking reactor.

The hydroprocessing carried out in the second hydroprocessing reactor 92 may be hydrotreating. In one aspect, the second hydrotreatment unit may be a hydrotreatment unit 14, in which case the second hydrotreatment hydrogen stream may be a hydrotreatment hydrogen stream passing through conduit 30. The second hydrotreatment reactor 92 is a hydrotreatment reactor, which is reported below a stream with a second branch 30 of the pipeline, and the feed stream in the pipeline 90 is a stream of raw materials for hydrotreating.

In the hydrotreating reactor 92, hydrocarbons with heteroatoms can be further demetallized, desulfurized, and de-nitrated by hydroprocessing as described above with respect to the hydroprocessing unit 12. Hydrotreating reactor 92 may also contain a hydrotreating catalyst, which is suitable for saturation of aromatic compounds, hydrodewaxing and hydroisomerization.

If the first hydroprocessing reactor 42 operates as a mild hydrocracking reactor, said first hydroprocessing reactor 42 can convert from 20 to 60 volume. % of raw materials boiling at a temperature above the boiling range of diesel fuel, to obtain a boiling point below the boiling point of the diesel fractions. The second hydroprocessing reactor 92 may have a very low degree of conversion and can be used mainly for desulfurization if combined with a mild hydrocracking reactor 42, in order to provide fuel performance, for example, to meet ultra low sulfur diesel fuel (ULSD) requirements )

A second hydroprocessing effluent stream transported through conduit 94 can exchange heat with a second hydroprocessed feed stream passing through conduit 90. A second hydroprocessing effluent conveyed through conduit 94 can be separated in a second cold separator 96 to produce a vaporous second effluent hydroprocessing products containing hydrogen in the head pipe 98 and a liquid second stream of hydroprocessing products in the bottom pipe 100.

The second cold separator 96 can operate at a temperature of 46 ° to 63 ° C (115 ° to 145 ° F) and a pressure that is slightly lower than the pressure in the second hydroprocessing reactor 92, taking into account the pressure drop to maintain hydrogen and light gases in the head a stream and usually liquid hydrocarbons in a bottom stream. The water stream can be removed from the sump of the second cold separator 96 through line 102.

A vaporous second hydrotreatment product effluent containing hydrogen passing through head pipe 98 can be recycled and added to the make-up hydrogen stream passing through pipe 20 upstream of the second compressor. In the “recirculation” embodiment of FIG. 1, a vaporous second hydroprocessing effluent comprising hydrogen transported through line 98 is added at a pipe connection point 25 to a make-up hydrogen stream transported through line 20 upstream of the first compressor 22. Make-up gas in line 20 and recycle gas in line 98 are combined and sent to line 26, then mixed and sent for compression, as described above. Accordingly, the first compressor 22 and the second compressor 32 downstream communicate with the head pipe 98.

The liquid second effluent of the hydroprocessing products passing through line 100 may be fractionated in a fractionation column 104, which may be a stripping column. In this case, before it is fed into the stripping column 104, the liquid second effluent of the hydroprocessing products transported through the pipeline 100 can be heated. The specified liquid second effluent of the hydroprocessing products can be stripped in a stripping column 104 using water vapor supplied from the pipeline 110 to obtain a stream of naphtha and light fractions discharged through the head pipe 112. The product stream can be diverted through the bottom pipe 114. In one an embodiment, the product stream is a stream of diesel fuel containing sulfur in an amount of less than 50 wppm qualified as LSD, and preferably less than 10 wppm qualified as ULSD. It is contemplated that stripper column 104 may operate as a fractionation column using a boiler (reboiler) instead of using steam for steaming.

By recirculating hydrogen from the second hydroprocessing unit 14 back to the discharge side of the first compressor 22, the second hydroprocessing unit can operate without a compressor for gas recirculation. The recycle hydrogen from the second hydroprocessing unit 14 is further compressed and used in the first hydroprocessing unit 12.

Figure 2 presents the embodiment of the "recirculation" of the device and method 8 ', in which the vaporous second effluent of the hydroprocessing products is recycled through line 98' to the second compressor 24 'and a hot separator is used upstream of the first cold separator. Many of the elements shown in FIG. 2 have the same construction as those shown in FIG. 1 and are denoted by the same reference numerals. The elements in FIG. 2, which correspond to the elements in FIG. 1, but have a different design, are indicated by the same reference numbers as in FIG. 1, but are marked with a dash symbol ('). The embodiment of FIG. 2 differs from that shown in FIG. 1 by the layout of the compressor section 10 ′ and the first hydroprocessing unit 12 ′.

In the compressor section 10 ′, the make-up hydrogen stream in the make-up hydrogen pipe 20 ′ is directed to the first compressor 22 to increase the pressure of the make-up hydrogen stream and obtain a first compressed make-up hydrogen stream in the pipe 24 ′. The first compressor 22 may be made in the form of a series of series-installed compressors.

A separation device 27 'mounted on the pipe 24' for the first compressed make-up hydrogen stream allows the selection of a part of the compressed make-up hydrogen to the first branch pipe 28 'and the selection of the second part of the compressed make-up hydrogen to the second pipe branch 30'. The second part of the compressed make-up hydrogen in the second branch 30 'of the pipeline is sent to the second installation 14 for hydroprocessing. The connection 25 'between the second branch pipe 28' and the head pipe 98 ', transporting a vaporous second effluent of the hydrotreatment products, provides communication between the specified head pipe 98' and the first branch 28 'of the pipeline. A pressure reducing valve installed on the first branch 28 'of the pipeline can equalize the pressure between the first stream of compressed make-up hydrogen and the vaporous second effluent of the hydroprocessing products to allow supply and mixing of these two streams in the pipeline 26'.

The resulting mixture of the second part of the compressed make-up hydrogen stream in the first branch of the pipeline 28 'and the vaporous second effluent of the hydroprocessing products in the pipeline 26' can be additionally compressed in the second compressor 32, which can be made in the form of a series of series-installed compressors, obtaining in the pipeline 34 second compressed make-up stream. Accordingly, the second compressor 32 downstream communicates with the head pipe 98 ', which directs the flow bypassing the first compressor 22.

A second compressed make-up hydrogen stream passing through conduit 34 can be combined with a recycle hydrogen stream passing through conduit 56 to form a first hydroprocessing hydrogen stream in conduit 36. Said first hydroprocessing hydrogen stream passing through conduit 36 taken from a second compressed make-up hydrogen stream can be combined with a first hydrocarbon feed transported through conduit 38 to produce a first hydroprocessing hydrocarbon feed passing through conduit 40. The rest of the embodiment of FIG. 2 operates as in FIG. 1, except as set forth below.

A second difference between the embodiment illustrated in FIG. 2 and that shown in FIG. 1 is the first hydroprocessing unit 12 ′. The first hydroprocessing unit 12 ′ may include a hot separator 120, which is downstream connected to the first hydroprocessing reactor 42 through a line 44 'and provides a vaporous stream of hydrocarbons in the head pipe 122, and a liquid hydrocarbon stream in the bottom pipe 124. The hot separator 120 operates at a temperature of 177 ° to 343 ° C (350 ° to 650 ° F) and preferably at a temperature of 232 ° to 288 ° C (450 ° to 550 ° F). The hot separator can operate at a pressure slightly lower than in the hydrocracking reactor 42, given the need for a pressure differential between them. The vaporous hydrocarbon stream discharged through conduit 122 can be cooled before entering the first cold separator 46. Accordingly, the vaporous first hydroprocessing effluent can be separated in the first cold separator 46 to produce a vaporous hydrocracking effluent containing hydrogen transported through the pipeline 48, and a liquid effluent of hydrocracking products in conduit 52. These streams are then treated as described above in relation to 1 shown in FIG. In this regard, the first cold separator 46 downstream communicates with the head pipe 122 of the hot separator 120.

The liquid hydrocarbon stream in the bottom conduit 124 may be fractionated in the fractionation portion 16 ′. According to one aspect, a liquid hydrocarbon stream passing through conduit 124 can be rapidly vaporized in a hot evaporation drum 130, resulting in a stream of light fractions in the head pipe 132 and a stream of heavy liquid fractions in the bottom pipe 134. The hot evaporation drum 130 may function at the same temperature as the hot separator 120, but at a lower gauge pressure, in the range of 1.4 MPa to 3.1 MPa (200 to 450 psig). The liquid stream of heavy fractions in the bottom conduit 134 may be further fractionated in the fractionation portion 16 ′. In accordance with one aspect, a liquid stream of heavy fractions transported through conduit 134 can be introduced into the stripper column 70 at a lower level than the feed point of the liquid stream of light fractions passing through conduit 62.

The rest of the embodiment of the invention illustrated in FIG. 2 may be the same as that described in FIG. 1, with a preliminary noted exception with respect to the compressor section 10 ′. The embodiment of the hot separator 120 just disclosed in FIG. 2 can also be used in the embodiment of FIG. 1.

Preferred embodiments of the present invention are described herein, including the best known to the inventors for carrying out the invention.

It should be understood that the illustrated embodiments are merely examples, and should not be construed as limiting the scope of the invention.

It is believed that a specialist in the art without further elaboration and research, using the above description of the invention, can use the present invention in its fullest extent. The preceding preferred specific embodiments should be understood, therefore, only as illustrative, not limiting in any way the rest of the description.

In the above description, all temperatures are given in degrees Celsius, and all fractions and percentages are by weight, unless otherwise indicated. The pressures are given at the outlet of the columns and, in particular, at the outlet of the steam stream from the columns having a number of exits.

From the above description, a person skilled in the art can easily establish the essential features of the present invention, and without going beyond the scope and essence of the invention can make various changes and modifications of the invention to adapt it to different conditions and applications.

Claims (9)

1. The method of hydroprocessing two streams of hydrocarbons, including
compressing the make-up hydrogen stream in the first compressor to produce a first compressed make-up hydrogen stream;
compressing the first part of the first compressed hydrogen feed stream in a second compressor to produce a second compressed hydrogen feed stream;
the selection of the second part of the first stream of compressed make-up hydrogen as a second hydrogen stream for hydroprocessing;
hydroprocessing a first hydrocarbon stream in the presence of a first hydroprocessing hydrogen stream comprising a second compressed make-up hydrogen stream and a first hydroprocessing catalyst to produce a first hydroprocessing effluent stream;
hydroprocessing a second hydrocarbon stream in the presence of a second hydroprocessing hydrogen stream comprising a first compressed make-up hydrogen stream and a second hydroprocessing catalyst to produce a second hydroprocessing effluent;
separating said second hydroprocessing product effluent to produce a vaporous second hydroprocessing effluent; and
adding the specified vaporous second effluent of the hydroprocessing products to the specified stream of make-up hydrogen upstream from the specified first compressor. 2. The method according to claim 1, wherein said first hydrotreatment stream is hydrocracked in the presence of a hydrocracking catalyst, and said second hydrotreatment stream is hydrotreated in the presence of a hydrotreatment catalyst. 3. The method according to claim 1, further comprising fractionating at least a portion of the first effluent of the hydroprocessing products to produce said second hydrocarbon stream, which is a diesel fuel stream. 4. The method according to claim 1, further comprising splitting the first effluent of the hydroprocessing products into a vaporous first effluent of the hydroprocessing products containing hydrogen and a liquid first effluent of the hydroprocessing products; compressing said vaporous first hydroprocessing effluent to produce a recycle hydrogen stream; adding a second stream of compressed make-up hydrogen to said vaporous first hydroprocessing effluent stream or to a recycle hydrogen stream to obtain said first hydroprocessing hydrogen stream. 5. The method according to claim 1, further comprising separating the second effluent of the hydroprocessing products to obtain a liquid second effluent of the hydroprocessing products and then fractionating said liquid second effluent of the hydroprocessing products to produce low sulfur diesel fuel. 6. Installation for hydroprocessing two streams of hydrocarbons, containing:
a make-up hydrogen pipeline for transporting a make-up hydrogen stream;
a first compressor that communicates with said feed hydrogen line and is designed to compress said feed hydrogen stream to produce a first compressed feed hydrogen stream;
a separation device that communicates with said first compressor and serves to separate said first stream of compressed make-up hydrogen into a first part transported by a first branch of the pipeline and a second part transported by a second branch of the pipeline;
a second compressor in communication with said first branch of the pipeline and for compressing said first part of said first stream of compressed make-up hydrogen to obtain a second stream of compressed make-up hydrogen in a second pipe for compressed make-up hydrogen;
a first hydroprocessing reactor in communication with said first branch pipe for hydroprocessing a first hydrocarbon stream;
a second hydroprocessing reactor in communication with said second branch pipe for hydroprocessing a second hydrocarbon stream;
a separator in communication with said second hydroprocessing reactor for separating a second effluent of the hydroprocessing products to produce a vaporous second effluent of the hydroprocessing products containing hydrogen passing through the head pipe;
moreover, the specified second compressor is in communication with the specified head pipe; and said first compressor communicates with said lead pipeline at a connection point on said hydrogen feed pipe. 7. The apparatus of claim 6, further comprising a cold separator in communication with said second hydroprocessing reactor, for separating the second hydroprocessing product effluent into a vaporous second hydroprocessing product effluent containing hydrogen transported through the head pipe and a liquid second effluent hydrotreatment products in the bottom pipeline, while the specified second compressor communicates with the specified head pipe at the connection point on the specified Hur branch conduit. 8. The apparatus of claim 6, wherein said first hydroprocessing reactor is a hydrocracking reactor and said second hydroprocessing reactor is a hydrotreating reactor. 9. The apparatus of claim 6, further comprising a fractionation column that communicates with said bottom pipe and is designed to fractionate said liquid second effluent from the hydrotreatment products and produce a diesel fraction.

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