SK166197A3 - Process for reverse staging in hydroprocessing reactor systems - Google Patents

Abstract

A hydrocarbon feed (1) is passed to a denitrification and desulfurization zone (10); passing said denitrification and desulfurization zone effluent to a purification/cooling zone (20) for removal of NH3 and H2S and cooling, and recovering from said purification/cooling zone a hydrogen/light hydrocarbon stream (30) and a liquid stream containing dissolved gases (35); passing said liquid stream containing dissolved gases to a separation zone (40) and recovering a light product (45), a liquid bottoms (50), and at least one side-cut product therefrom (52); passing said liquid bottoms (50) and said side-cut (52) product and said hydrogen/light hydrocarbon stream from step (30) (b) to a hydrocracking or a hydrotreating zone; passing said hydrocracking or hydrotreating zone effluent (65) to said denitrification and desulfurization zone (10).

Description

METHOD OF REVERSE TREATMENT IN HYDRO-PROCESS REACTOR SYSTEM

Technical field

The present invention relates to the field of hydroprocessing processes, in particular hydroprocessing processes with respect to high conversion, selectivity of products and selective heat treatment with respect to products having a specific boiling range.

BACKGROUND OF THE INVENTION

In the field of hydroprocessing processes and oil heat treatment, two approaches are known with a view to achieving a high degree of conversion. By "high conversion" is meant removal of sulfur and nitrogen compounds, hydrocracking, reduction of carbon atom range, and the like. Two common practices are:

(a) a long residence time in a reactor or a reactor at low space velocity; or

b) in a separate high conversion reactor after the impurity feed was reduced in the initial feed reactor.

The second approach using a separate purification reactor seems to be effective. This is because the impurities removed in the feed, i.e. by-products such as hydrogen sulfide, ammonia, are not present here at typically high concentrations, as in the first reaction stage. Such high concentrations may cause inhibition of reaction rates in the second reaction stage.

There are already several common approaches in this field to achieve good production selectivity. By selectivity it is meant to obtain an advantageous yield of material with a certain range of boiling points. These common practices include:

(a) recycling unwanted products for further fresh feed; or

b) treating the undesired products in a separate reaction step.

836 / B

Typical processes in the selective heat treatment section, taking into account specific boiling ranges, may be mentioned;

(a) exceeding the total supply to the place where we encounter the most problematic product specification; or

(b) adjusting the total feed to a lesser extent, followed by separate heat treatment of some or other of the dedicated products to meet the most problematic specifications.

SUMMARY OF THE INVENTION

Thus, it would be desirable to identify a hydroprocessing process whereby a higher conversion or better treatment is achieved, avoiding the shortcomings of the current known processes.

The present invention is directed to meet these requirements in a single reaction stage, requiring lower costs compared to several stages, while maintaining the advantages of a multi-stage process involving higher reaction rates or catalysts for pre-treated feeds.

Accordingly, it is an object of the present invention to provide a high-conversion, selective heat treatment, and product selectivity in a hydroprocessing reactor system, including a higher conversion or improved treatment in a reactor bed or beds, or an initial reactor series reactor and allowing generic feed modification. in the reaction zones that follow.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 is one embodiment of a flow chart of the process of the present invention using conventional devices for assembling different treatment zones;

In FIG. 2 is another embodiment of a process flow diagram of the present invention using separate devices for assembling different treatment zones.

836 / B

DETAILED DESCRIPTION OF THE INVENTION

A. Overview of the procedure, upper and lower reaction zones

The invention relates to a process for reversing the heat treatment of a hydrocarbon feed with high conversion, selective heat treatment and product selectivity in a reactor for a hydroprocessing system. The method consists in passing the hydrocarbon feed into a first cooking zone, for example a nitrogen and sulfur removal zone. In this zone, the hydrocarbon feed is contacted under heat treatment conditions, i.e., for removal of nitrogen and sulfur compounds, with a heat treatment catalyst, such as a nitrogen or sulfur removal catalyst. The effluent from this zone after removal of the nitrogen and sulfur compounds is further collected.

This effluent without nitrogen and sulfur compounds is passed further to the purification / cooling zone where ammonia and hydrogen sulfide are removed, in particular by washing with water. The effluent is cooled by any conventional method, for example in a heat exchanger. The effluent from this cleaning and cooling zone is a stream containing hydrogen and light hydrocarbons from the top and a liquid stream containing dissolved gases from the bottom. The stream containing hydrogen and light hydrocarbons is optionally fed to a second zone to remove hydrogen sulfide, usually with an amine adsorbent to remove hydrogen sulfide. The outlet from this zone after hydrogen sulfide removal is optionally fed to a second heat treatment zone, for example a hydrocracking zone, as tc below.

The liquid stream containing the dissolved gases is fed to a separation zone and any separation method, typically distillation, can be used. Thus, one or more reaction by-products or mixtures thereof are obtained as the product of the fraction of light hydrocarbons and other fractions from the bottom of the liquid products. The other fractions, i.e. the liquid fractions from the bottom or one or more of the side products, are fed to a second heat treatment zone, for example a hydrocracking zone. Here, the liquid fractions, the by-products and the other fractions come into contact with the hydrocracking catalyst. The outlet of the hydrocracking rasp is collected and then passed to the first heat treatment zone, according to one embodiment, to the nitrogen and sulfur removal zone.

836 / B

The use of the two bands may be varied according to the present invention. This means that the first and second zones for the heat treatment or reaction may be a hydrocracking zone or a zone for removal of nitrogen and sulfur compounds. In one embodiment of the present invention, the bottom zone is where the fresh feed first encounters a zone for removal of nitrogen and sulfur compounds. The upper zone is then hydrocracking. In another embodiment, the opposite is true. Thus, otherwise, each zone may be hydrocracking or each zone may thereby remove nitrogen and sulfur. Each zone may also be a combination or mixture of a hydrocracking zone and a nitrogen and sulfur removal zone.

B. Advantages of the Process of the Invention

The present invention describes a single reaction circuit. This one-step reaction reduces costs compared to using several circuits. And one single reaction zone according to the invention is associated with the advantages of higher reaction rates and catalyst savings compared to pre-treated feeds in a multi-stage system. According to the present invention, a finishing treatment is performed. the upper reaction zone or in the upper bed or upper beds of the reactor or reactors, while the general treatment of the feed takes place in the lower reaction zone that follows.

Another advantage of series configuration rather than using a parallel reactor configuration for initial conversion and high conversion is that gas circulation is kept to a minimum, thereby reducing both investment and operational costs. Basic costs are lower with respect to smaller equipment and less pipeline connections. Operating costs are lower due to the less compression necessary for gas recirculation. Gas circulation will be reduced with respect to the initial process in a separate plant or parallel reactor, since a) the high conversion outlet from the upper reaction zone serves as a partial thermal drop, thereby reducing the cooling requirements to start the next process in the following zones, b) unused the hydrogen in the upper conversion outlet of the upper zone serves as a partial source of hydrogen to start processing in the bands that follow and c) the high conversion outlet of the upper reaction zone aids in good distribution of fresh feed and hydrogen for reaction on the catalyst in the bands that follow. Thus, the advantage of using a single plant or circuit is the reduced investment costs as well as lower operating costs by:

836 / B, do not duplicate similar parts of the entire device in two separate bands, for example one for initial processing and one for high conversion.

Advantages of treating the pre-treated hydrocarbon in the upper reaction zone or the upper feed from the fresh feed include a) the upper catalyst bed is not contaminated with impurities from the feed, b) the reaction rate in the upper bed is not hampered by substantial amounts of thermal by-products such as ammonia; hydrogen sulphide and (c) the partial hydrogen pressure is maximum for new processes. According to a preferred embodiment, in the case of treatment of the residues, this process can prove its advantages in the lower reaction zones, which results in a reduced pulsating tendency.

C. Feeds and products

The feeds for use in the process of the present invention and the desired products obtained are otherwise conventional or known, as is the case with known feeds and products from and for hydrocracking and heat treatment. These are the supplies and products of U.S. Patents 5,277,793, 5,232,577, 5,073,530, 4,430,203 and 4,440,088, all of which are incorporated herein by reference. According to one preferred embodiment, the hydrocarbon feed may be a residue, a vacuum gas oil, middle distillates or mixtures thereof.

D. Reaction conditions and catalysts

Suitable hydrocracking catalysts and heat treatment catalysts include any conventional or known catalysts and reaction conditions. Both the catalysts and reaction conditions are disclosed in U.S. Pat. Nos. 5,277,793, 5,232,577, 5,073,530, 4,430,203 and 4,440,088, all of which are incorporated herein by reference. If the reaction zone is a nitrogen and / or sulfur removal zone, then contact occurs under appropriate conditions for removal of the nitrogen and / or sulfur compounds. If the reaction zone is hydrocracking, then contact occurs under hydrocracking conditions.

If the aforementioned heat treatment procedure is used with respect to the removal of nitrogenous and sulfur compounds, then these conditions are typically performed; reaction temperature 200 to 480 ° C, pressure 3550 to 35 500 KPa, hourly liquid space velocity 0.5 to 20, total hydrogen consumption 30 to 200 m ³ per 4.5 L liquid hydrocarbon feed. Catalyst for heat treatment bed

836 / B may be any Group VI metal or the corresponding compound, as well as Group VIII on a porous refractory such as alumina. Examples of such heat treatment catalysts are cobalt and molybdenum alumina, nickel sulfide, tungsten and nickel sulfide, cobalt or nickel molybdate.

If the feed hydrocracking procedure is used, the following conditions prevail: temperature 200 to 500 ° C, hourly liquid space velocity 0.1 to 15, reaction pressure 3550 to 35 500 KPa, hydrogen consumption 50 to 250 m ³ per 4, 5 L of liquid hydrocarbon feed. The hydrocracking catalyst will generally be a Group VI, VII or VIII metal corresponding to an oxide or sulfide on a porous refractory substrate such as silica or alumina. Examples of hydrocracking catalysts include molybdenum, tungsten, vanadium and chromium oxides or sulfides on any of the foregoing.

Generally speaking, if the reaction zone is a zone for removal of nitrogen and / or sulfur impurities, then the catalyst may be any operating under such conditions, similar to hydrocracking catalysts.

Detailed description of the pictures

Process modifications in the accompanying drawings and described in this section are readily apparent to those skilled in the art of petroleum refining processes and are within the scope of the present invention.

A. Figure 1

As can be seen from the diagram for FIG. 1, the catalytic reactions used in this process are carried out in two reaction zones 3 and 10, and the reactor 2 comprises both these zones 3 and 10. The initial treatment takes place in the second zone 10 and the high conversion treatment in the first zone 3. optionally other equipment such as conventional in hydroprocessing treatments such as preheating of liquid and gaseous feeds to the reactor (not shown), ammonia and hydrogen sulphide removal, effluent cooling and separation zone 20, optionally gas purge recycling zone 31, recirculation streams 30 and 32 product division a

836 / B distillation zone 40. A liquid stream from bottom 50 and / or a lateral or middle outlet 52 from the distillation zone 40 is fused to stream 54 and fed to the reaction zone.

3. The hydrogen treatment stream 60 is added to the recirculated gas stream 32 (also referred to as " hydrogen and light hydrocarbon stream " or " hydrogen sulphide effluent stream 32 ") Otherwise, a hydrogen treatment stream 70 may be connected to supply stream 7 instead or in addition to replenishing hydrogen into stream 32.

The hydrocracking or deeper heat treatment takes place in the reaction zone 3, depending on the type of catalyst used in this zone. The outlet 65 from the reaction zones opens into the reaction zone 10. The fresh inlet 1 is introduced in the middle between the reactor beds 3 and 10. Processing takes place in the presence of the outlet 65 from the upper reaction zone 3. The outlet 65 aids in distributing the feed 1 through the reaction zones 10. Likewise, outlet 65 aids as a heat sink well in the exothermic reaction in the reaction zone 10.

The effluent 15 from the lower zone 10 is treated with respect to the removal of ammonia and hydrogen sulfide in zone 20. For such removal of ammonia and hydrogen sulfide, conventional procedures are used, usually water washing. The zone 20 is also a cooling and separating zone producing a gas stream 20 and a liquid stream 35 containing dissolved gases. Conventional methods are used to remove both ammonia and hydrogen sulphide, as well as cooling and partitioning in zone 20. Zone 20 may include multiple units or subunits according to conventional ammonia and hydrogen sulphide removal, cooling and partitioning procedures. The hydrogen-rich gas stream 32 is recycled back to the reactors and then mixed with the supplemental hydrogen stream 60. Alternatively or in addition to mixing the hydrogen-rich stream 60 with the gas stream 32, the replenished hydrogen stream 70 is mixed with the oil stream 7. The recycle gas in stream 30 is optionally cleaned, for example on an amine adsorbent to remove hydrogen sulfide, in zone 31 before being recirculated to the reactors. The recycle gas from stream 30 (or stream 32 if purified further in zone 31) is optionally introduced. into stream 54 to feed into the first reaction zone 3 or is fed as stream 34 to feed stream 1 with introduction into the second reaction zone 10.

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B. Figure 2

The description of this figure is the same as that of figure 1, preferably of these differences. In Figure 1, the common reactor comprises both reaction zones, in Figure 2 the reactors 2 and 9 correspond to zones 3 and 10. In Figure 1, the recycle gas purification zone 31 is shown, in Figure 2 this zone is omitted.

Claims (19)

PATENT CLAIMS A process for the reverse conversion of a hydrocarbon feed with high conversion gain, a selective heat treatment with product selectivity in a hydroprocessing reactor system, characterized in that: a) a hydrocarbon feed consisting of residual oils, a vacuum gas oil, medium boiling distillates and mixtures thereof is passed into the nitrogen and sulfur removal zone, and is contacted there with nitrogen and sulfur removal catalysts at a temperature of from about 200 ° C to about 200 ° C; 480 ° C, a pressure of from about 3550 to about 35,500 KPa, an hourly liquid space velocity of from about 0.5 to about 20, and a total hydrogen consumption of from about 30 to about 200 m ³ per 4.5 L of liquid hydrocarbon feed, and is withdrawn such a quaternary discharge from the sulfur nitrogen removal zone, (b) this outlet is fed to a purification / cooling zone where ammonia and hydrogen sulphide are removed with simultaneous cooling, a stream containing hydrogen and light hydrocarbons as well as a liquid stream containing dissolved gases is removed from this zone; c) said liquid stream containing dissolved gases is fed into a separation zone and from there is obtained a light product, liquid fractions from the bottom and at least one side stream, d) bringing said liquid fraction from below, a side stream, and a hydrogen-containing hydrocarbon-containing outlet of step b) into a hydrocracking zone, wherein the components are contacted with a hydrocracking catalyst at a temperature of about 200 to about 500 ° C, a pressure of from about 3550 to about 35,500 KPa, an hourly flow rate of from about 0.1 to about 15, and a total hydrogen consumption of from about 50 to about 250 m ³ per 4.5 L of liquid hydrocarbon feed, recovering there from the outlet hydrocracking zone, and (e) the discharge from the hydrocracking zone is led to a nitrogen and sulfur removal zone. 30,836 / B 2. A reverse conversion process with high conversion gain, selective heat treatment and product selectivity in a hydroprocessing reactor system, characterized in that it is carried out in a single reactor comprising a higher conversion space or a deeper process treatment in the upper reactor zone or in the first to a reactor of a series of reactor embodiments, in that the feed in-line treatment is carried out in subsequent reaction zones. The method of claim 2, further comprising supplying hydrogen make-up to said higher reaction space or reaction zones following. The method of claim 2, further comprising; (a) withdrawing an outlet from the downstream zones, leading to the cooling zone; (b) a stream containing hydrogen and light hydrocarbons and a stream of light hydrocarbons containing dissolved gases are recovered from the cooling zone; (c) the stream containing hydrogen and light hydrocarbons is fed to said upper reaction zone; and d) the liquid stream containing the dissolved gases is fed to a separation zone. The process according to claim 3, wherein the feed is selected from the group of residual oils, vacuum gas oils and middle distillates or mixtures thereof, further characterized in that a stream of hydrogen and light hydrocarbons from step b) is fed to the hydrogen sulfide removal zone as is fed to a given upper reaction zone or first reactor in step c). The process of claim 4, wherein the reactor bands that follow are hydrocracking zones containing a hydrocracking catalyst, wherein the temperature in the hydrocracking zone is from about 200 to about 500 ° C, the reaction pressure is from about 3550 to about 350 ° C. 35,500 KPa, an hourly liquid flow rate of from about 0.1 to about 15, and a total hydrogen consumption of from about 50 to about 250 m ³ per 4.5 L hydrocarbon feed. 30,836 / B The method of claim 5, wherein the reactor bands that follow are the nitrogen and sulfur removal zones, and the method further comprises contacting a feed consisting of residual oils, a vacuum gas oil, intermediate distillates, or mixtures thereof with a catalyst for removing nitrogen and sulfur compounds at a temperature of from about 200 to about 480 ° C, a pressure of from about 3550 to about 35,000 KPa, an hourly liquid flow rate of from about 0.5 to about 20, and a total hydrogen consumption of from about 30 to about 200 m ³ to 4.5 l of liquid hydrocarbon feed and the outlet of the nitrogen and sulfur removal zone is collected. * The process of claim 4, wherein the reaction zones that follow are hydrocracking zones and the method further comprises using a hydrocracking catalyst and said hydrocracking zones with a feed consisting of residual oils, vacuum gas oils, middle distillate fractions, and mixtures thereof with a temperature of from about 200 to about 500 ° C, a pressure of from about 3550 to about 35,500 KPa, a liquid flow rate of from about 0.1 to about 15 per hour, and a total hydrogen consumption of from about 50 to about 250 m ³ per 4, 5 L of liquid hydrocarbon feed. The method of claim 7, wherein the upper reaction zone or first reactor is a hydrocracking zone and said method further comprising contacting at least a portion of the outlet of the nitrogen and sulfur removal zone with the hydrocracking catalyst in the hydrocracking zone at a temperature of about 200 to « about 500 ^dC , at a pressure of from about 3550 to about 35,500 KPa, at an hourly flow rate. a liquid velocity of from about 0.1 to about 15 and a total hydrogen consumption of from about 50 to about 250 m ³ per 4.5 L of liquid hydrocarbon feed. The process of claim 4 wherein the upper reaction zone or the first reactor is a nitrogen and sulfur removal zone. The method of claim 9, further comprising the steps of: (a) the effluent from the nitrogen and sulfur removal zone enters the purification and cooling zone to remove ammonia and hydrogen sulphide with cooling and is recovered 30 836 / B from this cleaning and cooling zone a stream of hydrogen and light hydrocarbons and a liquid stream containing dissolved gases, (b) a liquid stream containing dissolved gases is conducted into a partition to obtain a light product, a bottom product and at least one center-discharged product; and (c) introducing all of the outlets of step (b) into said upper reaction zone. 12. A process for treating a hydrocarbon feed comprising: (a) conducting the hydrocarbon feed into the second hydrotreatment zone, wherein the hydrocarbon feedstock contacts the second hydrotreatment treatment catalyst under a hydrotreatment condition, and the effluent from the second hydrotreatment zone is drained; and (b) the heat-treated product is fed into a vapor-liquid separation zone and from there a light product and a further fraction from the bottom group, one or more intermediate fractions and mixtures thereof are obtained; (c) introducing said further fractions into a first hydrogenation heat treatment zone where, under hydrogenation conditions, the hydrocarbon feed contacts the first hydrogenation catalyst and the effluent from the first hydrogenation zone is discharged therefrom; and d) conducting an outlet from the first hydrogenation zone to a second hydrogenation zone. 13. The process of claim 12 wherein hydrogen is added to said second hydrogenation zone. 14. The method of claim 12, further comprising: (a) introducing an outlet from the second hydrogenation zone into the ammonia and hydrogen sulphide removal zone and the cooling zone; (b) recovery from this zone to remove ammonia and hydrogen sulphide, as well as to cool the streams of hydrogen and light hydrocarbons and the Liquid hydrocarbon stream containing dissolved gases; 30,836 / B (c) conducting the hydrogen and light hydrocarbon stream to the first hydrogenation zone; and d) introducing a liquid hydrocarbon stream containing dissolved gases into the vapor-liquid separation zone. The process according to claim 14, wherein the hydrocarbon feed is selected from the group of residual oils, vacuum gas oil, middle distillates and mixtures thereof. 16. The method of claim 12, wherein the second hydrogenation zone is a nitrogen and sulfur removal zone having a temperature of from about 200 to about 480 [deg.] C, a pressure of from about 3550 to about 35,500 KPa, an hourly liquid flow rate of about 0.5 to about 20, and a total hydrogen consumption of from about 30 to about 200 m ³ per 4.5 L of liquid hydrocarbon feed, said second hydrogenation catalyst comprising catalysts for removal of nitrogen and sulfur compounds. 17. The method according to claim 16, characterized in that the second hydrogenation zone ¹ is a hydrocracking zone. The method of claim 12, wherein the first hydrogenation zone is a hydrocracking zone having a temperature of from about 200 to about 500 ° C, a pressure of from about 3550 to about 35,500 KPa, an hourly liquid flow rate of from about 0.1 to about 500C. 15 and a total hydrogen consumption of from about 50 to about 250 m ³ per 4.5 L of liquid hydrocarbon feed, said first hydrogenation catalyst comprising a hydrocracking catalyst. The method of claim 12, wherein the first hydrogenation zone is a nitrogen and sulfur removal zone.