DE2133332A1 - Hydrosulphurisation of heavy hydrocarbons - in split flow process - Google Patents

Abstract

Hydrodesulphurisation of a heavy petroleum feed is carried out by a split flow process. The liquid phase feed is passed into an intermediate position of a hydrodesulphurisation catalyst zone maintained at 600-850 degrees F and 500-5000 psig and having a 1st catalyst zone below and a 2nd stage catalyst zone above the intermediate position, and lower boiling hydrocarbon liquid is maintained in the 2nd catalyst zone by passing hydrogen upwardly into the 1st catalyst zone at a rate of at least 3000 SCF/bbl of feed to flow serially through the 1st and 2nd catalyst zone. The pref. feeds are deasphalted atmospheric and vacuum residues topped to at least 550 degrees F and charge stocks contg. at least 25 wt.% of material boiling above 850 degrees F.

Description

Process for the hydrogenative conversion of hydrocarbons The invention relates to catalytic desulfurization and catalytic hydrocracking heavy hydrocarbon material. In particular, the invention relates to a method lower for increased sulfur reduction and increase in selective yields boiling hydrocarbons in a particularly preferred boiling range.

The catalytic treatment of heavy hydrocarbon materials.

than at temperatures of 260-44-OC and elevated pressures in the presence of hydrogen to influence hydrocracking is known. In general, there are known ones Hydrocracking process in heating heavy hydrocarbon material to a desired one Reaction temperature and mixing either before or after heating with a desired H2 content and passing the mixture through an upper part of the reactor or a reactor section containing a bed of granular catalytic material are filled. A liquid phase flows through the reactor in contact with the catalyst, which is composed of higher hydrocarbons of the inlet atom and Contains dissolved or adsorbed hydrogen, along with the hydrogen stream down. Alternatively, the liquid output stream can be slightly below the top of the reactor and the hydrogen can be introduced slightly above the bottom of the reactor. Through this the vapor phase portion of the input stream flows together with stripping hydrogen and the hydrogen released from the input stream by the upper part of the reactor upwards (gas-liquid countercurrent process).

In hydrodesulfurization processes which have been proposed so far, becomes a mixture of hydrogen and a hydrocarbon fraction with one large boiling range in a reactor using a hydrodesulfurization catalyst contains in the middle reactor area, entered. The mixture is at one temperature preheated, which corresponds to the hydrodesulfurization temperature, so that the phase separation takes place at the entrance of the mixture. The gas phase, consisting essentially of hydrogen and lower boiling hydrocarbons from the input stream through the reactor upwards, being in the manner with a suitable catalyst comes in contact that the vapor phase transformation in the complete absence of any Liquid takes place At the same time, the liquid phase, consisting of higher boiling points, flows Hydrocarbons and dissolved hydrogen through the reactor downwards with the Catalyst contact occurs. This process can be called a dual stream hydrodesulfurization process are designated.

An object of this invention is to improve the effectiveness of a such dual stream hydrodesulfurization process.

Another object of this invention is to increase the number of USB routes lower boiling hydrocarbons by hydrocracking heavy hydrocarbon material in a two-stream hydroconversion process.

The solution to these objects according to the invention relates to a method for the hydrogenation conversion of hydrocarbons with simultaneous desulfurization and cracking by moving down a heavy hydrocarbon feedstock a catalyst zone consisting of a first below the feedstock inlet located and a second catalyst layer arranged above this inlet is introduced and hydrogen is countercurrent to the heavy hydrocarbon feedstock in the first Catalyst layer flows in, with suitable Hydrogen feed lower boiling carbon in the second catalyst layer be held.

It has now been found that desulfurization and hydrocracking heavy hydrocarbon material in a two-stream hydrogen contact process can be achieved by downing a heavy hydrocarbon feedstock through a catalyst zone, which consists of a first below the starting material inlet located and its second catalyst layer arranged above this inlet exists, flows. The flow of hydrogen takes place in the first catalyst layer as countercurrent to the heavy hydrocarbon feedstock, while in the second Catalyst layer a lower boiling liquid is obtained - and this lower boiling liquids from this layer under hydrocracking conditions how temperature, pressure and space velocity are subtracted. The reduced ones Sulfur-containing hydrocarbons are generated from the first and second catalyst layers under hydrodesulfurization conditions such as temperature, pressure and space velocity obtain.

A crucial aspect of this invention is that the lower boiling point Liquid (hereinafter referred to as "liquid") in the second catalyst zone is obtained. It has been found that when the liquid is in the above The catalyst layer located at the starting material inlet is increased Hydrosulfurization under hydrodesulfurization conditions and increased conversion and selectivity in the conversion to lower boiling hydrocarbons in a particularly preferred boiling range under hydrocracking conditions such as pressure, Temperature and space velocity occurs.

When the method according to the invention is carried out, the difficult thing occurs Hydrocarbon material in a catalyst zone, which consists of a first below the starting material inlet located catalyst layer and a second there is a layer of catalyst material arranged above the inlet. The term "above" in relation to the second Catalyst layer only means that the second catalyst layer in relation to the rising hydrogen gas and in relation to the rising volatile hydrocarbons and the carried ones liquid hydrocarbons from the first in the second catalyst layer have passed over, stands. The word '! Above' is used to define the flow conditions the first catalyst layer used. These flow conditions are related on the gas flows increasing from the first to the second catalyst layer of hydrogen, volatile hydrocarbons and entrained lower boiling points liquid hydrocarbons, in countercurrent with the heavy hydrocarbon material flowing off. The second catalyst layer can, in the spatial sense, be directly above the first Be arranged catalyst layer so that first and second catalyst layer in a vertical reactor with an inlet for the heavy hydrocarbon feedstock. It is true that the present Invention an arrangement for the second catalyst layer in the sense that this Layer in a separate reactor, which is connected to the first reactor via a line is connected, can be arranged, but in a preferred inventive The process is carried out in the first and second catalyst layers in a vertical reactor available. In the two catalyst layers there is a catalyst, the has either hydrodesulfurization or hydrocracking activity, or a combination both shows at the applied process conditions such as temperature, pressure and Space. In addition, the catalyst can be in the first catalyst layer the same as or different from the second layer. For example Different catalysts can use different hydrodesulfurization and hydrocracking catalysts or a combination of hydrodesulfurization and hydrocracking catalyst.

The heavy carbon pulp feed enters the catalyst zone and is in flow relation to the first catalyst layer. Hydrogen will at the bottom of the first Catalyst layer introduced and / or in the middle of this layer. The hydrogen occurs here with the first Catalyst layer flowing materials in countercurrent exchange and rises together with the volatile hydrocarbons and the entrained liquid hydrocarbons into the second catalyst layer. The volatile and the liquid hydrocarbons, which collect in the second catalyst layer, leave it in a volatile manner State and are made in a known manner, e.g. by cooling the hydrocarbon vapors and liquids, recovered. The one leaving the second catalyst layer Hydrogen can enter the first catalyst layer together with fresh hydrogen to be led back. In addition, hydrogen can optionally be used with the heavy hydrocarbon feedstock and this mixture can be mixed at room temperature or at temperatures which equals hydrodesulfurization or hydrocracking temperatures, into the catalyst zone can be entered. A particular aspect of this invention is maintenance a liquid in the second catalyst layer. Generally it will be a liquid in the second catalyst zone by the speed of the in the first catalyst zone - Maintain hydrogen entering with the aid of each of the processes mentioned. Around a liquid in the second catalyst layer when using hydrogen to maintain it has been found that hydrogen velocities of at least 534 Nm 2 / m) liquid starting charge, preferably 534 - 4453 Nm5H2 / m3 liquid starting charge, are required in the first catalyst layer. The required hydrogen needs not to be present in pure form and gases with more than 65 vol. 0 H2 can be used will. The term "hydrogen" also refers to that obtained as a by-product Reforming hydrogen, based on hydrogen, which is the partial oxidation of hydrocarbons and subsequent conversion (shift conversion) originates from and on by electrolysis obtained hydrogen. These hydrogen gas flows, e.g. originate from catalytic Reforming processes in which the hydrogen is used as exhaust gases, such as methane and ethane Contains impurities are sufficient. The above hydrogen velocities affect the actual speeds at which the hydrogen enters the first catalyst layer flows in to maintain a liquid phase in the second catalyst layer.

The amount of the liquid hydrocarbon charge used in the first Catalyst layer can be changed a little by changing the amount of hydrogen flowing on it can be varied. In general, a large amount of liquid used is preferred. Dicses means an amount required for maximum catalytic effectiveness in the conversion of the starting material into lower boiling hydrocarbons sufficient.

The liquid present in the second catalyst layer originates generally of the heavy hydrocarbon feedstock and consists of a lower boiling hydrocarbon that is initially in the starting material is present or is formed in the course of the method according to the invention. in the generally the liquid material has a boiling point below 45,400. Preferred is a liquid located in the second catalyst layer, which is at least contains about 90% by weight of a liquid with a boiling point below 454 ° C. Particularly a liquid fraction boiling below 454 ° C. of at least approximately is preferred 97% by weight, in particular at least about 99% by weight.

The inventive method can be used in hydrodesulfurization and applied in hydrocracking heavy hydrocarbon feedstocks, sub the term "hydrodesulfurization process" means a non-destructive hydrogenation, the main influence being sulfur removal. In hydrated desulphurisation low or negligible proportions of lower boiling hydrocarbons obtained from the heavy iohydrocarbon feedstock per once through. Generally, less than about 15 weight percent is at 34300 and higher boiling levels converted, preferably less than about 5% by weight.

Hydrocracking is understood here as hydrogenative degradation, with a considerable part of the product at one temperature boils, those below the boiling point of the heavy hydrocarbon feedstock lies. In general, the conversion varies per single pass of the at 454 ° C and higher boiling starting material from about 20 to about 80 weight percent, preferably from about 30 to about 65 weight percent.

The hydrodesulfurization and hydrocracking conditions such as pressure, temperature and space velocity can be about a large.

Range can be varied. Conditions applied are those that in one case it will cause the removal of piles and in the other it will increase it Yield of lower boiling hydrocarbons lead.

The scope of the process of the invention also relates to a catalyst in the first and second catalyst layers under process conditions such as pressure and temperature causing hydrodesulfurization during the same catalyst at other pressure and temperature conditions to hydrocrack heavy hydrocarbon material can serve.

A large number of heavy hydrocarbon fractions and / or distillates can be used as starting material in the process according to the invention. Such heavy hydrocarbon fractions include boiling crude oils throughout the range, topped crude oils or top residues, atmospheric distillates, vacuum column sumps, Sump products, which plants for the short-term decomposition of petroleum products Achieving a low viscosity (viabreaker bottoms product), heavy Circulation products from thermal and catalytic cracking, etc. and mixtures two or more of the above materials. A particularly preferred heavy one Hydrocarbon feedstocks are the deasphalted atmospheric and vacuum column sumps, which were obtained at temperatures of at least 2880C and atmospheric pressure, as well as such starting materials and mixtures thereof which contain at least about 10 % By weight at 45400 and higher boiling hydrocarbons, preferably about 25% by weight, contain.

The process conditions of the first and second catalyst layers in the two-stream process according to the invention consist in temperatures of about 316 to about 454 ° C, preferably from about 385 to about 413 ° C, for hydrodesulfurization and from about 413 to about 441 ° C for hydrocracking; the prints are of about 35.2 to about 352 kg / cm2, preferably from about 70.3 to about 141 kg / cm2 for those Hydrodesulfurization and from about 105 to about 176 kg / cm2 for hydrocracking, as well LHSV (liquid hourly space velocities) (volume of starting material / volume of catalyst and hour) from about 0.1 to about 10, preferably from about 0.2 to about 1.5 for the hydrodesulfurization and from about 0.2 to about 2.0 for hydrocracking.

In general, approximately the same conditions are preferred applied in the first and second catalyst layers, although the gas velocities differ from each other in the first and second catalyst layers, based on the portion of hydrogen that mixes with the heavy hydrocarbon feedstock initially introduced into the catalyst zone and / or consumed in the process. Therefore, the hydrogen velocities in the second catalyst layer a little higher than the hydrogen velocities in the first catalyst layer be.

In addition, different LHSVs can be present in the two catalyst layers be regulated, depending on the percentage conversion and / or the desulfurization per unique throughput.

In general, the IHSV in the second catalyst layer are greater than in the first. In addition, if the catalyst layers are in separate Reactors are arranged, temperature and pressure can be varied.

The hydrodesulfurization catalyst can be any of the transition metals, their metal oxides, metal sulfides or other metal salts that promote hydrodesulfurization catalyze and are not poisoned by H2S or other sulfur compounds, contain. A berorzúgtér catalyst contains the oxides and / or the sulfides, e.g. the oxides or sulfides of molybdenum, tungsten, iron, cobalt, nickel, chromium, and the like Metals. Vanadium compounds can also in some cases be used. A particularly active combination consists of the metal oxides or sulfides of the VI B group of the PSE with metal oxides or sulfides of the VIII. Group. E.g. mixtures with molybdenum oxide and cobalt oxide, molybdenum oxide and nickel oxide, Tungsten sulfide and nickel sulfide and the like can be applied.

A particularly active catalyst contains one as cobalt molybdate known mixture, which can be a mixture of cobalt and molybdenum oxides, where the atomic ratio Co: Mo can be between 0.4 and 5.0. This catalyst or any of the other catalysts above can be used in neat or alternate form a suitable oxidic adsorbing carrier, such as aluminum oxide, SiO2, zirconium, Thorium, iSagnesium, titanium oxide, bauxite, acid activated clays or a combination these oxides can be used in diluted form.

The starting materials used to convert the specified hydrocarbon Hydrocracking catalyst used can be a crystallized, metallic aluminosilicate zeolite, with a metal derived from the platinum group (e.g. platinum or palladium), which is deposited on or mixed with the aluminosilicate zeolite, be. The crystallized zeolites are characterized by a highly ordered crystal structure made of, have uniform pore openings and an anionic aluminosilicate cage structure, in which aluminum oxide and SiO2 sit closely together. Through this are there are a large number of active positions, so that together with the regular ones Pore openings that allow easier access to certain molecular structures will. It has been found that crystalline aluminosilicate zeolites have an effective Pore diameters of about 6-15 AtStröm, preferably 8-15 Angstroms, mixed with a metal of the platinum group, especially after the base exchange, to the content to reduce alkali oxides (e.g. Na2O) in the zeolite to less than about 10% by weight, effective hydraulic cracking catalysts, especially for the hydrocarbon starting materials considered here, represent.

The catalyst can also contain a hydrogen-supported catalyst a metal of group VIII of the PSE, such as nickel, cobalt, iron or one of the metals from the platinum group such as palladium, platinum, iridium or ruthenium on a suitable one Carrier, be. Generally, an oxide or sulfide of Group VIII metal (especially iron, cobalt or nickel) mixed with an oxide or sulfide or a Group VI B metal (preferably molybdenum or tungsten) is preferred. Suitable Carriers including acidic carriers are: SiO2-aluminum oxide, 810 2-magnesium oxide and other known carriers for gray catalysts; the acidic clays; fluorinated Alumina; Mixtures of inorganic oxides such as aluminum oxide, SiO2, zirconium oxide and titanium oxide with enough acidic properties to have high cracking activity guarantee.

You can also use the various metals, metal oxides and sulfides used on a mixture of carrier materials. For example, can Zeolite and an aluminum oxide together; mixed as a carrier material in variable Proportions are used, with different metals deposited on the carrier material are.

For a better assessment of the invention, the following examples are which are not intended to represent a limitation of the invention: Example 1 A split flow vertical pressure reactor was used. with a capacity of 1,500 ccm, equipped with a starting material inlet in the middle Height of the reactor, a discharge for products formed on the bottom and on the Head of the reactor, a gas inlet at the bottom of the reactor, a heater, as well a first and second sieve catalyst test bed containing 700 cc of catalyst each used below and above the starting material inlet. In each The catalyst bed contained nickel oxide (3% by weight) molybdenum oxide (13 6% by weight) on alumina (1.59 mm tablets). An atmospheric top residue -Safaniya-, properties see Table I was with approximately 93 ° C in the stream to the first hydrogenation catalyst bed with an LISV of 1.0 (volume liquid of starting material / volume of catalyst and hour).

Hydrogen is flowing through the gas line in countercurrent at one speed of 2850 Nm3E2 / m3 starting material blown at 41300 and 105 kg / cm2 in the two Catalyst layers. A product flowing out of the two catalyst layers was collected and pooled.

Example 2 A downflow reactor was used with starting material - and hydrogen introduction at the top of the reactor and a product discharge at the bottom and used at the top of the reactor.

The catalyst used and the starting material were identical with those in Example 1. Hydrogen and charge flow down onto the catalyst with an LlISV of 1.0, at 41300, 105 kg / cm2 and a hydrogen velocity of 2850 Nm3 H2 / m) starting material. The product was collected.

Example 3 A countercurrent reactor equipped with a material inlet and gas discharge at the top of the reactor and a gas inlet and product discharge at the bottom of the reactor were used.

The catalyst and starting material were the same as in Example 1. Hydrogen and starting material were blown onto the catalyst in countercurrent: LHSV 1.0, 413 ° C, 105 kg / cm2, 2850 Nm3H2 / m3 starting material. The product was collected.

The "Analysis of the Collected Products for Examples ii 2 and 3" is given in table t together with the properties of the starting material.

T A B E L L E I Starting material: Top residue (Safaniya) products Starting material Example 1 Example 2 Example 3 Two upstream downstream countercurrent countercurrent collected *) product (wt%) H2S + NH3. 0.5 0.4 0.4 Cl 0.3 0.6 0.2 C3 @ 0.2 0.5 0.2 C4 @ 0.2 0.6 0.2 C5 0.2 0.8 0.2 C6 - 93 ° C) 0.4) 0.9) 1.4) C6-204 ° C 12.2 2.3 2.3 93-204 ° C 11.8) 1.4) 0.9) 204-343 ° C 4.5 26.5 6.3 14.0 343-454 ° C 20, 3 13.3 14.6 21.3 454 ° C and higher 78.2 46.3 73.4 61.9 sulfur, wt% 4.5 1.23 2.5 2.39 Desulfurization wt% 72.7 44.5 46.9 Conversion of those boiling at 454 C and higher Products 40.3 6.2 20.8 *) Calculated as H2-free combined top and bottom products T A B E L L E II H2 circulation speed Product of (4) Product of (5) 3117Nm3H2 / m3 285 Nm3H2 / m3 Product analysis S% by weight 1.22 2.09 C residue "" 7.93 12.52 N "" 0.15 0.25 Desulfurization "" 64.1 38.5 Example 4 In a reactor according to Example 1 with 300 ccm of catalyst in each of the two catalyst layers each nickel oxide (3% by weight) molybdenum oxide (13.6% by weight) on 1.59 mm aluminum oxide tablets Arabic vacuum-topped crude oil was downstream of the first hydrogenation catalyst bed given with an LHSV of 1.0. The properties of this Arabian crude are as follows: Properties of the starting material (Arabic vacuum-topped Crude oil) API in grade 8.7 C residue% by weight 17.55 S% by weight 3.4 N,% by weight 0.28 vacuum distillation % By weight start of boiling - 204 ° C 204 - 343 ° C -343 - 45400 454 ° C - end of boiling 100 At 413 ° C, 105 kg / cm2 and a hydrogen circulation rate of 3117 Nm3 / m3 The starting material in the two catalyst layers became an aus'den layers collected product combined.

Example 5 In a reactor according to Example 1 and the catalyst ratios according to Example 4, the starting material used in Example 4 was the same Process conditions, however, processed with only 285 i'3H2 / m3 of starting material. A combined product from the catalyst layers is obtained.

The properties of the products from Examples 4 and 5 are in given in Table II.

The results in Table I demonstrate the excellent performance of the method according to the invention in the original conversion of 454 ° C and higher boiling Material with a single throughput compared to the countercurrent process (example 2) and the downstream process (Example 3). There is also a considerably higher desulfurization obtained under hydrocracking conditions than in the known process (Examples 2 and 3). Example 1 has a conversion of 40.3 wt% for 454 ° C and higher boiling points Material reached. In comparison, this conversion is 100% higher than in the countercurrent process and around 700% higher than the drainage method. The desulfurization was twice that of countercurrent and downstream processes. The presence of fluids is of particular importance to achieve optimal desulfurization, as can be seen from the results in table II emerges. In particular, a comparison of Examples 4 and 5 reveals the particular ones Aspect of the method according to the invention, namely maintaining a low boiling liquid in the second catalyst layer. A comparison of hydrogen circulation rates from 3117 Nm3H2 in the process according to the invention to 285 Nm3H2 for the already known Process provides a desulfurization of 64.1% for the invention and 38.5% for the known method. The inventive method results in a desulfurization, which is about twice as large as in the known method.

Claims (3)

P a t e n t a n s p r ü c h e 1. Process for the conversion of hydrocarbons under hydrogenation simultaneous desulphurisation and cracking, which is not the case n e t that heavy hydrocarbon feedstock down into a catalyst zone, from. a first one above the starting material inlet and one second catalyst layer arranged below the inlet is introduced and hydrogen in countercurrent to the heavy hydrocarbon feedstock flows into the first catalyst layer, hydrogen being supplied by suitable means lower boiling liquid hydrocarbons in the second catalyst layer be held. 2. The method according to claim 1 d a d u r c h g e k e n n -z e i c h n e t that the lower boiling liquid hydrocarbons in the second Catalyst layer through a hydrogen velocity of at least 534 Nm3H2 / m3 Starting material, preferably from 534-4452 Nm3H2 / m3 starting material will. 3. The method according to claim 1,, d a d u r c h g e k en n -z e i c h n.e t g that low boiling liquid hydrocarbons are retained, which is at least about 97% by weight, preferably at least about 99% by weight, below Boil 4540C.