EP0516187A2 - Process for the hydroconversion of heavy and residual oils - Google Patents

Abstract

The invention relates to a process for the hydroconversion of heavy and residual oils, spent oils and waste oils, tar sands and the like by contacting with hydrogen at a hydrogen partial pressure between 50 and 300 bar, a temperature between 250 and 500 DEG C, a throughput of 0.1 to 5 tonnes/m<3> and hour, and a gas/liquid ratio between 100 and 10,000 standard m<3>/tonne. The technical object and aim of the invention is to provide a process for processing heavy and residual oils, wherein excessive foam formation is avoided and the reaction space of the hydrogenation reactors is more fully utilised. To achieve the technical object, the catalyst or added additives in the hydrotreatment of the feedstocks has a particle size distribution between 0.1 and 2000 mu m, preferably 0.1 and 1000 mu m, and the fraction of the particles of catalyst or additive having a particle size of 100 mu m or more amount to between 10 and 40% by weight, preferably 10 or 30% by weight, of the total quantity of catalyst or additive added to the reactor system.

Description

The invention relates to a method for the hydrogenative conversion of heavy and residual oils, waste and waste oils, tar sands and the like. Like. With contents of heavy metals (V + Ni) of 200 ppm or more, asphaltenes of 2 wt .-% or more, Conradson coal of 5 wt .-% or more and a density of less than 20 ° API, which with a catalyst or additive or a mixture thereof from the group consisting of red mud, Fe₂O₃, iron ores, hard coal, brown coal, hard coal coke, brown coal coke, preferably impregnated with heavy metal salts, activated carbon, carbon blacks from the gasification of solid or liquid fuels, cokes from hydrogenation or distillation residues are contacted with Hydrogen at a hydrogen partial pressure between 50 and 300 bar, a temperature between 300 and 500 ° C, a throughput between 0.1 to 5 t / m³h, a gas / liquid ratio between 100 and 10,000 Nm³ / t, gas velocities of 3 cm / s or higher and a catalyst or additive concentration of 0.1 to 10% by weight in a bottom phase reactor system through which the bottom flows upwards.

The feedstocks are characterized by a high metal, sulfur and asphalt content as well as a high tendency to form coke. The invention relates in particular to a catalytic process for converting hydrocarbon-containing feedstocks such as Orinoco Belt Crudes, Maracaibo Lake Crudes, tar sands from Athabasca and Canada crude oils such as Cold Lake in the sump phase in the presence of hydrogen. The feedstocks have a sulfur content between 2 and 6%, a metal content (vanadium and nickel) of 200 to 1400 ppm and more, a density of less than 20 ° API, a coking residue of more than 2% and a residue content of more than 40% .-% (500 ° C⁺).

Depending on the desired conversion rate, hydrocracking conditions (pressure, temperature, gas / oil ratio etc.) and tendency to coke, a catalyst or

Additive such as activated coke from hard coal or lignite, soot, red mud, ferric oxide, blast furnace dust, ash from the gasification process of the aforementioned crude oils, natural, inorganic minerals containing iron such as laterite and limonite, in an amount of 0.5 to 15% by weight. % Based on the liquid or liquid and solid use added to the hydrogenation process.

Underlying state of the art

According to the prior art (cf. EP 0 073 527), the catalytic treatment of heavy and residual oils takes place in the presence of brown coal coke, which is mixed with catalytically active metals, preferably with their sulfates, oxides or sulfides or with dust from the lignite gasification in a concentration of 0.1 to 10 wt .-%, based on the heavy residual oils. These catalysts or additives are used in a very fine distribution with a grain size of less than 90 µm.

The US Pat. No. 3,622,498 also describes a process in which asphalt-containing hydrocarbon inserts are converted in the presence of hydrogen at 68 bar and 427 ° C. with a slurry of small catalyst particles which contain at least one metal from element group Va, VIa or VIIIa of the periodic table.

The American patent US 4,396,495 describes a process for the conversion of hydrocarbon-containing dark oils in suspension reactors using finely divided metal catalysts, such as vanadium sulfide, with a particle size of 0.1 to 2000 μm, preferably 0.1 to 100 μm. A silicone based anti-foaming agent is also added to to reduce foam formation in the hydrocracking zone, where the reaction takes place at 510 ° C., 204 bar and a catalyst concentration of 0.1 to 10% by weight. This method cannot be used at temperatures above 430 ° C because the silicones decompose and lose their activity. The silicon remains in the low-boiling fraction and leads to difficulties in the upstream process.

Canadian Patent CA 1,117,887 describes a hydrocracking process for converting heavy oil into lighter hydrocarbons under high pressure and high temperature. The heavy oil is mixed with a finely divided brown coal additive with a grain size of less than 149 μm, which is loaded with at least one metal from element group IVa or VIII of the periodic table.

US Pat. No. 4,591,426 also describes a hydroconversion process for heavy feedstocks with a metal content of at least 200 ppm at temperatures above 400 ° C. and a total hydrogen pressure of 1022 bar using a natural inorganic material such as laterite or limonite.

In the case of reactors with moving catalyst beds, 1 to 15% by weight of particles with particle sizes between 1270 and 12700 µm, based on the feed, are fed in, these making up 20 to 80% by weight of the content of the reaction zone.

It can be seen from this that, in the treatment of hydrocarbons, it has not hitherto been recognized that under catalytic sump phase conditions using cheap catalysts or additives which have been described above, foam is produced which, at gas velocities of more than 3 cm / s, the amount of liquid in the reaction zone reduced. These high gas velocities are achieved in industrial reactors.

Presentation of the invention

The invention has for its object to avoid excessive foam formation in a method of the type mentioned.

Another object of the invention is the improved utilization of the reaction zone or the hydrogenation reaction.

According to the invention, these objects are achieved by a method for the hydrogenative conversion of heavy and residue oils, waste and waste oils, tar sands and the like. Like. With contents of heavy metals (V + Ni) of 200 ppm or more, asphaltenes of 2 wt .-% or more, Conradson coal of 5 wt .-% or more and a density of less than 20 ° API, which with a catalyst or additive or a mixture thereof from the group red mud, Fe₂O₃, iron ores, hard coal, lignite, hard coal coke, brown coal coke, preferably impregnated with heavy metal salts, activated carbon, carbon blacks of the gasification of solid or liquid fuels, cokes from hydrogenation or distillation residues are contacted with Hydrogen at a hydrogen partial pressure between 50 and 300 bar, a temperature between 300 and 500 ° C, a throughput between 0.1 to 5 t / m³h, a gas / liquid ratio between 100 and 10000 Nm ^{3 /} t, gas velocities of 3 cm / s or higher and a catalyst or additive concentration of 0.1 to 10% by weight in a bottom phase reactor system through which the bottom flows upwards, characterized in that the catalyst or additive has a particle size distribution between 0.1 and 2000 μm, preferably 0.1 and 1000 μm, and the proportion of the catalyst or additive particles having a particle size of 100 μm or more is between 10 and 40% by weight, preferably 10 and 30% by weight, of the total amount of catalyst or additive added to the reactor system.

According to the invention, it is hereby disclosed for the first time that, from a fluid dynamic point of view, the amount of liquid in the hydrocracking zone of the reactor initially increases for a given gas velocity when larger particles are used.

The present invention enables improved utilization of the reaction zone by using two metering streams of the catalyst or additive with two different particle size distributions.

One embodiment of the present invention discloses a conversion process for heavy crude oils with a density of less than 20 ° API, more than 200 ppm metal content and more than 5% by weight Conradson coal in the presence of hydrogen and a catalyst or additive in a bottom phase reactor, in which an upward three-phase flow is formed.

The catalyst can comprise metals from element group Va, VIa or VIIIa of the periodic table, with or without porous support, on which metals also contained in the crude oil are deposited.

It has been found that larger particles with grain sizes in the range of 100 microns and more at gas velocities of 3 cm / s and more are able to reduce the foaming in the reactor when they are used in an amount of not less than 0.5 wt .-% of the heavy oil input are fed to the hydrocracker. It is important to point out that if the foam formation in the reactor is reduced and the resulting increase in the liquid volume, the desired conversion of fractions boiling above 500 ° C. into lower boiling fractions can be achieved at moderate temperatures.

In addition, the present invention discloses that for very high conversion rates (90% and more) of fractions boiling above 500 ° C at moderately high flow rates (0.5t / m³h or more), a considerable proportion of small particles (below 50 microns) is needed , since this brings significant advantages for the hydrogenation capacity of the catalyst system.

Although the thermodynamic, fluid dynamic and kinetic relationships in the bottom phase hydrogenation with the addition of additives or catalysts in a bottom-flow tube reactor have not yet been completely clarified, it is assumed that the coarse grain fraction limits the foam formation or the gas residence time and that the amount of liquid is limited to Cost of the gas portion within the reactor, which is reflected by the differential pressure across the reactor height as well expresses the conversion rate and the preheating temperature. This phenomenon is noticeable at gas velocities in the reactor of more than 3 cm / s, temperatures of more than 250 ° C and pressures between 50 and 300 bar.

A measure of the hydrogenation capacity of the catalyst-additive system used is the ratio x _A : x _R (x _A = asphalt conversion rate according to DIN 51 525 and x _R = residue conversion [500 ° C⁺]), which under the most favorable conditions, ie if avoided of asphalt and coke deposits, gives a value close to 1. It could be shown that for a high residue conversion (X _R ≧ 87%) the ratio x _A : x _{R is} close to 1 if not less than 1% by weight of a fine grain fraction (less than 50 µm) based on the heavy oil input is used.

These facts have led to the present proposal for the use of a double metering system for the addition of an optimum desired particle size distribution for the purpose of improved utilization of the bottom phase hydrogenation reactor of the bubble column type.

Through two different and independent metering systems, the highly active fine grain fraction with a grain size of less than 100 µm, preferably a grain size of less than 50 µm, and the coarse grain fraction of a less active catalyst with a second metering system or inert material with a grain size of 100 to 2000 microns, preferably 150 to 1000 microns, which serves to adapt the system to the fluid dynamic requirements, the amount of liquid is maximized in the bottom phase reactor.

The corresponding catalyst mixture, which is formed from additives of two different particle size distributions, can also be prepared beforehand in another separate apparatus, in order then to be brought into contact with the oil insert via a single metering system. A remarkable aspect of the present invention is that two separate particle size distributions of the catalyst or the additive are used, both fractions being able to consist of the same or different materials.

The present invention discloses a method for treating heavy oils of various origins, such as petroleum, shale oil, tar sand, etc. These heavy oils have a high metal and asphaltene content and a high tendency to form coke. High metal concentrations (vanadium and nickel) of over 200 ppm, asphaltene contents over 2% by weight, Conradson coal values over 5% and more than 50% by weight residue fraction (500 ° C⁺) are typical.

The invention is concerned with a hydroconversion process in which the use of heavy oil in the presence of hydrogen with a catalyst or additive, such as activated coke, lignite, red mud, iron III oxide, blast furnace dust, ash from the gasification process of heavy oil, natural inorganic iron-containing mineral such as limonite or laterite, which in an amount of 0, 5 to 15 wt .-% is added in relation to the liquid content, is contacted.

If these catalysts or additives are added for addition to the heavy crude oil via two separate, independent metering systems, a metering system is provided for adding the highly active fine grain fraction, which has a grain size of less than 100 μm, preferably less than 50 μm. The coarse grain fraction, which influences the fluid dynamic behavior of the liquid phase reaction system and increases the liquid filling in the reactor, is entered via the second metering system, this fraction being characterized by a grain size between 100 and 2000 μm, preferably 150 and 1000 μm.

The proportion of the coarse grain fraction is between 5 and 80% by weight, preferably between 10 and 30% by weight, of the total amount of catalyst or additive.

A special embodiment of the invention is characterized in that the coarse grain fraction contains a proportion of 0.0 to 70% by weight, preferably less than 50% by weight, of fine particles with a particle size of at most 100 µm.

Furthermore, it is preferred that the proportion of the coarse grain fraction is 20% by weight or more, based on the total amount of the catalyst or additive used.

A further preferred embodiment is characterized in that the proportion of the coarse grain fraction is 20% by weight and in the subsequent operating period is at least 5% by weight of the amount of catalyst or additive.

Furthermore, it can also be preferred that the coarse grain fraction is added only when starting up or discontinuously in the course of the operating period.

A method in which the fine grain fraction used as the additive and the coarse grain fraction do not consist of the same material is particularly advantageous. In this case the following combinations are preferred: Fine grain fraction Coarse grain fraction Red mud Coal soot ground brown coal ground brown coal ground brown coal natural materials containing iron Bituminous coal or ground brown coal natural inorganic materials containing iron natural inorganic materials containing iron natural inorganic materials containing iron Hard coal or petroleum coke natural inorganic materials containing iron Soot from gasification processes

It has also proven to be advantageous to use calcium or magnesium compound as the coarse grain fraction to improve the further utilization of the hydrogenation residue.

Brief description of the figures in the drawings

FIG. 1 shows the hydroconversion process according to the invention with subsequent distillation and hydrosulfurization in a flow diagram.

FIG. 2 shows a double logarithmic plot of the cumulative weight fractions over the logarithm of the particle sizes of samples A and B according to Tables 1 and 2.

FIG. 3 shows a corresponding application as in FIG. 2 for two samples which belong to a normal distribution, and for mixtures of these samples.

Figure 4 shows the effect of the proportion of the coarse grain fraction on the differential pressure over the reactor height of the first reactor.

Furthermore, the description of the invention contains Tables 1 to 8 with the measurement results explained in the description.

Detailed description of the invention

According to FIG. 1, the fine-grain fraction is introduced via line 1 with a grain size of less than 100 μm, preferably less than 50 μm, from the storage vessel 2 discontinuously via valve 3 into a weighing container 4, from which the desired catalyst is fed via a continuous screw conveyor 5 or the amount of additive is fed via line 6 to the mixing container 13. The concentration of fine catalyst particles in the mixing container is set to 0.5 to 6% by weight, preferably to 0.5 to 3% by weight. The coarse grain fraction of the single-use catalyst or additive, which according to the invention has grain sizes of 100 to 2000 μm, preferably has 150 to 1000 microns supplied. The coarse grain fraction is provided via line 7 in the storage vessel 8 and fed discontinuously to the weighing container 10 via valve 9. The desired amount of coarse grain fraction is introduced into the mixing container 13 via a continuous screw conveyor 11 and mixed with the heavy oil and fine grain fraction fed via line 16, so that a concentration of coarse catalyst particles based on the heavy oil of 0.5 to 13%, preferably 0 , 5 to 6% is set. The invention is not limited to the illustrated embodiment with the two dosing systems described. The different grain fractions of the catalyst can also be supplied in other ways.

The heavy oil and the two grain fractions of the catalyst or additive are fed from the mixing container 13 via line 14 to a high-pressure pump 15 and via line 15 'to the heat exchangers 49 and 50, in which this material flow is preheated using the heat of reaction of the reaction products. The fresh hydrogen is fed via line 61, the hydrogen-containing cycle gas via line 59 to the cycle gas preheater 63, where the gas is heated to 200 to 500 ° C. and is fed to the heater 18 together with the preheated feed stream from line 50 ′.

The reactor system consists of one or at least two reactors connected in series. To be favoured three reactors connected in series. The reactors 20, 24 and 27 are vertical tubular reactors with or without internals, which are operated with the flow direction from bottom to top. Here the conversion takes place at temperatures between 400 and 490 ° C, preferably 430 and 480 ° C, a hydrogen partial pressure between 50 and 300 bar and a circulating gas volume of 100 Nm³ / t to 10000 Nm³ / t. A quasi-isothermal mode of operation of the reactors is possible by supplying cold gas via lines 21, 23 and 26.

In downstream hot separators, which are operated at approximately the same temperature level as the reactors, the unconverted portion of the heavy and residual oils used as well as the solids is separated from the gaseous reaction products under process conditions. The bottom product of the hot separator is expanded in a multi-stage flash unit. In the case of the combined operation of the bottom and gas phases, the top product of the hot separators, the flash distillates and any crude oil distillate fractions to be processed are combined and fed to the downstream gas phase reactors. Hydrotreating or mild hydrocracking is carried out on a catalytic fixed bed under trickle flow conditions under the same total pressure as in the sump phase.

After intensive cooling and condensation, gas and liquid are separated in a high-pressure cold separator Cut. The liquid product is relaxed and can be further processed in standard refinery processes.

The gaseous reaction products (C₁ to C₄ gases, H₂S, NH₃) are largely separated from the process gas, the remaining hydrogen is recycled as recycle gas.

According to the invention, two or three separate and independent metering systems are required in order to add the fine grain fraction with a grain size of less than 100 μm by one metering system and the coarse grain fraction with a grain size between 100 and 2000 μm by another metering system. The proportion of the coarse grain fraction in the total amount of catalyst is 5 to 80%, preferably 10 to 30%, the total amount of catalyst or additive is between 0.5 and 15% by weight, based on the heavy crude oil used.

It has been found that by controlling the amount of solids in the reactor, the amount of liquid in the reactor can be optimized so that the conversion of the heavy crude oil in the reaction system increases while the preheating temperature is reduced, thereby reducing the investment and operating costs of the preheater system.

The process according to the invention has particular advantages in the event that the gas velocity in the Reactor under reaction conditions is greater than 3 cm / s based on the reactor cross section, which is normally true for gas velocities in industrial reactors.

It was found that at gas velocities in the reactor of more than 3 cm / s and without the use of a coarse grain fraction, the liquid filling remains very low, which can be recognized from a low differential pressure with a low conversion rate and a high preheating temperature. On the other hand, too large a proportion of coarse-grained fraction causes these particles to accumulate in the reactor over time, so that the amount of liquid in the reactor and thus the on-stream factor of the reaction system decreases again.

As a rule, the same additive or catalyst material is added as fine grain and as coarse grain fraction. However, it is also possible and in some cases even advantageous to use additives of different compositions for the fine and coarse grain fraction, e.g. B. Fe₂O₃ as a fine grain fraction with a particle size with an upper limit of 30 microns and for the coarse grain fraction activated coke from lignite with a lower grain size of 100 microns.

The two catalyst fractions do not necessarily have to be fed to the catalyst-oil mixing container 13 (FIG. 1) via two separate metering systems. but can also be mixed beforehand and added directly as a catalyst mixture. The only decisive factor is the use of two different particle size distributions of the catalyst or additive from the same or different chemical species. The use of these two catalyst fractions leads to the unexpected result described in the invention.

Tables 1 and 2 show the cumulative weight distributions of samples A and B (coarse-grain and fine-grain fractions), which are each produced by a special grinding process.

These cumulative weight distributions of samples A and B from Tables 1 and 2 were shown in double logarithm in FIG. This plot shows that samples A and B are very well approximated by straight lines in the range from 1 to 99% of the accumulated weight fraction. This is congruent with what is known for samples which are obtained by a single or a repeated grinding process, in which a target yield is given with a predetermined sieve size (see Robert Perry, Chemical Engineers Handbook, 5th edition, chapter 8).

The present invention also allows closed-circuit grinding, in which the ground product is separated and the coarse material in the Grinding device is returned. This customary procedure is not the same as mixing separate catalyst streams of different grain sizes, but aims to achieve a certain yield with a given sieve size.

FIG. 3 shows mixtures of samples A and B - sample C (50% A and 50% B, table 3), sample D (30% A and 70% B, table 4), sample E (10% A and 90% B, Table 5), - and it can be seen that the mixtures cannot be represented by straight lines like the pure samples, but result in curves.

$\text{1n (-1n [\%η/100]) = 1na + b 1n d (2)}$

%η:

kumuliertes Gewicht unterhalb einer vorgegebenen Korngröße d [Gew.-%]

d :

Korngröße [µm]

Dies erlaubt erfindungsgemäß die Identifizierung von in Hydrocrackingreaktoren eingesetzten Mischungen zweier oder mehrerer Korngrößenverteilungen mit sehr unterschiedlichen Korngrößen.The reason why mixtures of two or more streams originating from two or more grindings and obtained with a predetermined sieve size do not behave linearly is given in equation 2.

${\text{\% η / 100 = exp [-ad}}^{\text{b}}\text{] (1)}$

$\text{1n (-1n [\% η / 100]) = 1na + b 1n d (2)}$

% η:

accumulated weight below a given grain size d [% by weight]

d:

Grain size [µm]

According to the invention, this allows the identification of mixtures of two or more particle size distributions with very different particle sizes used in hydrocracking reactors.

n:

Anzahl der experimentellen Punkte

y:

1n [- 1n (η/100)]

x:

1n (d)

Es wurde festgestellt, daß die Partikelgrößenverteilungen von Proben A und B, welche durch Mahlprozesse erhalten wurden, mit einem Korrelationskoeffizienten R² von mehr als 0,96 (R² >0,96) durch Geraden angenähert werden können. Für die Proben C, D und E, die Mischungen aus A und B sind, ergeben sich für die Geradendarstellung Korrelationskoeffizienten R² von weniger als 0,96 (R² <0,96). Dies macht deutlich, daß diese Proben sich nicht mit guter Näherung als Geraden darstellen lassen. Durch die vorliegende Erfindung kann gezeigt werden:

• a) Zwei oder mehr separate Additiv- oder Katalysatordosiersysteme führen der Hydrocrackzone unterscheidbare Additiv- oder Katalysatorkorngrößenverteilungen zu.
• b) Die Zugabe nur eines Katalysatorstromes in die Hydrocrackzone erfüllt die Bedingungen R²<0,96 nach Gleichung 2 nicht, wenn eine Ausgleichskurve nach der Methode der kleinsten Fehlerquadrate über den gesamten Bereich der Größenverteilung [(1 %) ≦ d ≦ 99 %] zugrundegelegt wird.

Table 6 shows the results of linear regression - calculated as correlation coefficient R² according to equation 3.

n:

Number of experimental points

y:

1n [- 1n (η / 100)]

x:

1n (d)

It was found that the particle size distributions of samples A and B, which were obtained by milling processes, with a correlation coefficient R² of more than 0.96 (R²> 0.96) can be approximated by straight lines. For samples C, D and E, which are mixtures of A and B, correlation coefficients R² of less than 0.96 (R² <0.96) result for the straight line representation. This makes it clear that these samples cannot be represented as straight lines with good approximation. The present invention can show:

• a) Two or more separate additive or catalyst metering systems supply distinguishable additive or catalyst particle size distributions to the hydrocracking zone.
• b) The addition of only one catalyst stream to the hydrocracking zone does not meet the conditions R² <0.96 according to equation 2 if a compensation curve based on the method of least squares over the entire range of size distribution [(1%) ≦ d ≦ 99%] is used becomes.

Both cases a) and b) are analogous, because it was found for the first time that only a catalyst mixture with a correlation coefficient ≦ 0.96 according to equation 2 is able to simultaneously reduce foam formation in the bottom phase reactor and also to minimize the addition of catalyst.

Für die minimale Gesamtkatalysatormenge gilt:

${\text{(Gew.-\%)}}_{\text{min}}{\text{= (Gew.-\%}}_{\text{grob}}{\text{)}}_{\text{min}}{\text{+ (Gew.-\%}}_{\text{fein}}\text{)}$

Die Katalysatormenge kann minimiert werden, wenn gerade die zur Vermeidung der Schaumbildung erforderliche Mindestmenge an Grobkornfraktion eingesetzt wird. Durch das doppelte Katalysatordosiersystem ist eine größere Flexibilität zur Reduzierung der Katalysatorgesamtmenge gegeben. Beim Einsatz zweier Katalysatordosiersysteme kann unter Betriebsbedingungen, wenn die Schaumbildung unter Kontrolle gebracht ist, der grobe Katalysator durch die Feinkornfraktion ersetzt werden. Da letztere die Koksbildung vermindert, wird hierdurch wiederum eine Verringerung der zuzugebenden Menge an Feinkornfraktion ermöglicht, so daß eine Minimierung der Gesamtzugabemenge in das Reaktorsystem ermöglicht wird.As previously shown, mixing two or more original ground size distributions can minimize the amount of catalyst in the hydrocracking reactor. This is the case since the fine grain fraction is suitable for reducing the coke formation which is caused by polymerization reactions. In the event that the proportion of fine grain fraction in the total amount of catalyst is very large, coke formation is minimized. It could be shown, however, that a certain amount of coarse grain fraction is also required to prevent foam formation in a bubble column reactor when hydrocracking reactions are carried out. In order to minimize the total amount of the catalyst or additive, it is necessary to work with a minimum amount of coarse grain fraction. This can be shown mathematically by the simple relationship below.

${\text{(\% By weight) =\% by weight}}_{\text{rough}}{\text{+\% By weight}}_{\text{fine}}$

The following applies to the minimum total amount of catalyst:

${\text{(\% By weight)}}_{\text{min}}{\text{= (\% By weight}}_{\text{rough}}{\text{)}}_{\text{min}}{\text{+ (\% By weight}}_{\text{fine}}\text{)}$

The amount of catalyst can be minimized if the minimum amount of coarse grain fraction required to avoid foam formation is used. The double catalyst metering system gives greater flexibility to reduce the total amount of catalyst. When using two catalyst metering systems, the coarse catalyst can be replaced by the fine-grain fraction under operating conditions when the foam formation has been brought under control. Since the latter reduces coke formation, this in turn enables a reduction in the amount of fine-grain fraction to be added, so that a minimization of the total amount added to the reactor system is made possible.

A preferred mode of operation is therefore the supply of the fine-grain and coarse-grain fractions through two separate metering systems.

The procedure to create a solid powdery mixture beforehand before filling it into the feed container, e.g. B. in a separate container is not recommended because the advantages of parallel dosing systems are lost. A previously prepared mixture of fine grain and coarse grain fraction, which is introduced as a common solid stream into the mixing container 13, is recognized by a lower value for the correlation coefficient R² (R² ≦ 0.96).

It was found that minimizing the addition of catalyst or additive to the hydrocracking reactor has very great advantages, not only in terms of minimizing operating costs due to the lower catalyst consumption, but also in that a smaller amount of coarse grain fraction is required to avoid foam formation and thereby the amount of catalyst settling in the reactor is reduced, which leads to a larger reactor volume and thus to a higher conversion under the same operating conditions (temperature, space velocity, etc.). This allows the required reactor temperature to be reduced for a certain degree of conversion which is favorable for the overall process. Low gas production and low hydrogen consumption due to a lower temperature level are important variables for the economy of the entire process.

This invention can also be used for the hydrogenation of mixtures of heavy, residual and waste oils with ground lignite and / or hard coal, the oil / coal weight ratio preferably being between 5: 1 and 1: 1. The coal can be used as a coarse grain fraction with a corresponding proportion of a grain size of 100 µm and more.

After leaving the reactor system 20, 24, 27, the hydrocracking product is fed via line 28 into the first hot separator 29 in order to separate the gas / vapor phase from the heavier liquid products which contain unconverted residues, catalyst and additive. The temperature of the hot separators 29 and 33 is regulated in a range from 300 to 450 ° C. by supplying quench gas via lines 32 and 34, which is fed in at the bottom. The second hot separator 33 mainly serves as a scraper for the gas phase reactors 40 and 46.

In the case of a combined bottom and gas phase process, the top product of the second hot separator 33 is combined via line 36, the flash distillate 77 as well as the crude oil distillate 36 ', which is produced elsewhere, and the gas phase reactors 40 and 46 at the same total pressure and approximately the same or fed to a somewhat reduced temperature as in the bottom phase reactor. The operating conditions of these reactors are according to the invention for the pressure between 50 and 300 bar, for the temperature between 300 and 450 ° C and for the gas / liquid ratio between 50 and 10000 Nm³ / t. Hydrotreating or mild is carried out in this conventional reactor Hydrocracking at fixed bed reaction zones under trickle flow conditions using a conventional hydrodesulfurization catalyst or a mild hydrocracking catalyst from groups VIa or VIIIa of the periodic table on an alumina support.

The product is fed via line 47 to intensive cooling and condensation (49, 50). The heat of reaction is used to preheat the fresh insert. The gas / liquid mixture is fed to the high-pressure cold separator 52 via line 51. The liquid product is relaxed and can then be fed to the standard refinery technology.

After passing through the cold separator 52, the gaseous reaction product is separated as much as possible from the process gas which is discharged via line 56. The remaining hydrogen is fed to the compressor 58 via line 57 and returned to the process via line 59. The bottom product of the hot separators 29 and 33 is fed via lines 32 and 34 to a multi-stage flash unit 65 and 72, decompressed and the residue of the used catalysts or additives is removed for workup, for example by carbonization, gasification or solids separation, via line 73 in order to be used again later can.

example 1

A vertical bubble column reactor without internals, the temperature of which is controlled via the outlet temperature of a preheater system and via a cold gas quench system, is charged with a specific throughput of 1.5 t / m³h with vacuum residue from a conventional residual oil of Venezuelan origin at a hydrogen partial pressure of 190 bar, whereby 2000 Nm³ of hydrogen can be used per ton of residue. The gas velocity is 6 cm / s. 2% by weight of lignite coke with a sharp upper grain limit at 90 μm are added to the feed product. Under these process conditions, a temperature in the reactor of 455 ° C. is reached at a preheater outlet temperature of 447 ° C. The differential pressure across the reactor height is about 100 mbar. A residue conversion of approximately 45% is achieved under these conditions.

The system was then operated with two different dosing systems. One supplied 1.4% by weight of lignite coke based on the use with a grain size of less than 90 μm, while the second fed 0.6% by weight of lignite coke based on the use with a grain size of more than 150 μm and less than 600 μm fed. The total amount of catalyst was again 2% by weight. The differential pressure increased from 100 mbar to approximately 300 mbar, while the preheater outlet temperature decreased from 447 ° C to 438 ° C. At the same time, the conversion rate (RU) of the residue rose from 45 to 62%.

RU_EIN/AUS =

Massenstrom Rückstand 500 °C⁺ in den Eingangs-/Ausgangsströmen

The conversion rate is calculated as follows.

RU _{ON / OFF} =

Mass flow residue 500 ° C⁺ in the input / output flows

Example 2

In a continuously operated hydrogenation system with three series-connected vertical sump phase reactors without internals, the vacuum residue of a Venezuelan heavy oil with the addition of 2 wt .-% Fe₂O₃ with a sharp grain limit at 30 µm with 1.5 m³ hydrogen per kg residue, 6 cm / s gas velocity and a hydrogen partial pressure of 150 bar. To achieve a residue conversion rate (conversion) of 90%, an average temperature of 461 ° C. was set via the series-connected sump phase reactors. The specific throughput was 0.5 kg / l. H.

If 25% of the additive used against a sieve fraction of Fe₂O₃ with a particle size distribution were exchanged from 90 to 130 µm, the differential pressure increased over the reactor height from 70 to 400 mbar. With a constant conversion rate of 90%, the reactor temperature was 455 ° C. With a specific throughput of 0.75 kg / h. 1, a conversion of 78% was achieved at an average reactor temperature of 455 ° C. and a conversion of 90% of the residue at an average reactor temperature of 461 ° C. Additive (catalyst) 2 wt .-% Fe₂O₃ spec. Throughput kg / 1. H middle Temperature ° C Conversion% A 100% by weight 30 µm 0.5 461 90 B 75% by weight 30 µm 0.5 455 90 25% by weight 90-130 µm C. like B 0.75 455 78 D like B 0.75 461 90

With the proposed use of two additive mixtures which differ with respect to the grain size ranges, an increase in performance in the bottom phase reactors (specific throughput) is possible at a constant temperature level of 50%.

Example 3

Another test demonstrates the special effectiveness of the two separate dosing systems. In this test, brown coal coke particles that were too 30 wt .-% grain sizes from 100 microns to 500 microns, fed to Venezuelan heavy oil by a single metering system. The 826 hour test was carried out in a system consisting of three sump phase reactors at an average temperature of approximately 460 ° C., a pressure of 260 to 205 bar, a total amount of catalyst of 2 to 3% by weight based on the residue used and a gas / liquid ratio between 1800 Nm³ / t and 2700 Nm³ / t and a gas velocity of approximately 6 cm / s. Table 7 shows the results of this test. It can be seen that the differential pressure over the first reactor increases slowly but steadily over time, due to a solid accumulation. The increase in the differential pressure cannot be reduced, even if the amount of catalyst is reduced from 3 to 2%. Consequently, a slow decrease in the conversion rate was observed with time, which was caused by the decrease in the effective reaction volume due to the filling of the reaction volume of the hydrocracker with solid. It becomes clear that with this method the reactor slowly fills up with solid matter, as a result of which the conversion rate in the reactor system decreases and such a process becomes uneconomical for industrial use.

In contrast, it could be shown that the differential pressure can be influenced when using two separate and independent metering systems according to this invention can (Figure 4); an increase or decrease depends on the amount of the coarse grain fraction used (50/200 µm with 70%> 100 µm). When the catalyst is fed through two separate and independent metering systems, one for the fine grain fraction of less than 30 µm and the other for the coarse grain fraction with 50/200 µm, the differential pressure is completely stable despite full filling of the reactor.

In the event that 2% by weight of coarse grain fraction (50/200 µm with 70%> 100 µm) and 2% by weight of fine grain fraction (below 30 µm) are used, the differential pressure increases at a rate of 5 mbar / h . If the addition of the coarse-grain fraction is stopped and replaced by an additional 2% by weight of fine-grain fraction, so that the total amount of catalyst is still 4%, the differential pressure drops at a rate of 7 mbar / h. This test was carried out at a total pressure of 140 bar, a gas / liquid ratio of 1500 Nm³ / t and a gas velocity of 6 cm / s.

This example clearly shows the advantage of using two dosing systems to limit the amount of solids and thus maintain the liquid filling in the reactor system, which enables effective control of the conversion and the preheater outlet temperature.

Example 4

A natural mineral Fe₂O₃-containing catalyst with a grain size of less than 20 µm is fed to the reactor through one of two installed metering systems. A coarse grain fraction with a grain size of less than 300 µm and a 50% proportion of particles with a grain size of less than 100 µm is supplied by the second metering system.

The total amount of catalyst was 3.1% based on the feed. The insert consisted of Morichal vacuum residue. The total pressure in this test was 170 bar with a hydrogen partial pressure of 130 bar. The gas velocity in the reactor system was 7.8 cm / s. The proportion of cycle hydrogen gas 1700 Nm³ / t, the average reactor temperature 464 ° C and the specific throughput (space velocity) 0.7 t / m³h (see Table 8).

The fine grain fraction (1.1% by weight based on the feed) with a grain size of less than 20 µm and the coarse grain fraction (2% by weight based on the use) with a grain size of less than 300 µm and a proportion of 50% by weight % with a grain size of less than 100 µm was fed to the reactor in two separate metering systems. Under these operating conditions the conversion rate was 92%, the asphaltene conversion 90% and the coke production 1.2% (test 1, table 8).

If, under these operating conditions, the amount of fine grain fraction (below 30 µm) is reduced to 0.6% by weight and the amount of coarse grain fraction (below 300 µm) with 50% by weight below 100 µm is reduced to 2.5% by weight. % is increased while maintaining a total catalyst quantity of 3.1% by weight, the crude oil conversion is of the same order of magnitude, namely 92%. However, the asphaltene conversion drops to 65%, while the coke formation increases to 2.5%, which leads to considerable problems when working up in the hot separator (Test 2, Table 8).

A 92% residue conversion and a 90% asphaltene conversion can also be achieved when the coarse grain fraction increases to 2.5% by weight if the total amount of catalyst increases by 0.5% by weight to a total of 3.6% by weight (Test 3, Table 8).

After the initial operating conditions have been reached, an asphalt conversion rate of 90% and a 1.2% coke formation are again achieved.

• a) durch die Mischung von zwei oder mehreren unterschiedlichen einer Normalverteilung entsprechenden Korngrößenverteilungen an einem beliebigen Stadium der Katalysatorherstellung, wobei die Mischung durch R² < 0,96 charakterisiert ist oder
• b) durch die getrennte Zugabe zweier oder mehrerer Korngrößenverteilungen (R² ≧ 0,97) an irgendeiner Stelle des Reaktionssystems vor oder am Eingang des Hydrocrackreaktors.

Tabelle 1 Gewicht in Abhängigkeit von der Korngrößenverteilung für eine konventionelle Probe nach der Mahlung (A) d (µm) Probe A Gew.-% zwischen d (µm) Probe A Gew.-% unter d (µm) > 500 0 500/315 1,4 1,4 315/200 26,1 27,5 200/125 16,5 44,0 125/90 11,7 55,7 90/69 11,9 67,6 63/45 10,9 78,5 45/32 6,5 85,0 27/21 4,0 89,0 21/15 3,0 92,0 15/10 3,0 95,0 0/7 2,0 97,0 7/5 2,2 99,2 5/2,5 0,8 100,0 2,5/1,5 - - 1,5/0,5 - - < 0,5 - - Tabelle 2 Gewicht in Abhängigkeit von der Korngrößenverteilung für eine konventionelle Probe nach der Mahlung (B) d (µm) Probe B Gew.-% zwischen d (µm) Probe B Gew.-% unter d (µm) > 500 500/315 315/200 200/125 125/90 90/69 63/45 45/32 27/21 3,3 3,3 21/15 5,3 8,6 15/10 12,2 20,8 10/7 12,0 32,8 7/5 4,0 36,8 5/2,5 24,5 61,3 2,5/1,5 15,0 76,3 1,5/0,5 18,0 94,3 < 0,5 5,7 100,0 Tabelle 3 Gewicht in Abhängigkeit von der Korngrößenverteilung für zwei konventionell gemahlene Proben und für eine Mischung 50 %A/50 %B (C) d (µm) Probe A Probe B Probe C Probe C Ausbeute unter d(µm),Gew.-% Gew.-% zwischen d (µm) > 500 0 500/315 1,4 0,7 0,7 315/200 26,1 13,0 13,7 200/125 16,5 8,3 22,0 125/90 11,7 5,9 27,9 90/69 11,9 6,0 33,9 63/45 10,9 5,5 39,4 45/32 6,5 3,2 42,6 27/21 4,0 3,3 3,2 45,8 21/15 3,0 5,3 4,2 50,0 15/10 3,0 12,2 7,7 57,7 10/7 2,0 12,0 7,0 64,7 7/5 2,2 4,0 3,1 67,8 5/2,5 0,8 24,5 12,7 80,5 2,5/2,5 15,0 7,5 88,0 1,5/0,5 18,0 9,0 97,0 < 0,5 5,7 2,9 99,9 Tabelle 4 Gewicht in Abhängigkeit von der Korngrößenverteilung für zwei konventionell gemahlene Proben und für eine Mischung 30 %A/70 %B (D) d (µm) Probe A Probe B Probe D 30%A/7%B Probe D Ausbeute unter d(µm), Gew.-% Gew.-% zwischen d (µm) > 500 0 0 500/315 1,4 0,42 0,42 315/200 26,1 7,83 8,25 200/125 16,5 4,95 13,20 125/90 11,7 3,51 16,71 90/69 11,9 3,57 20,28 63/45 10,9 3,27 23,55 45/32 6,5 1,95 25,50 27/21 4,0 3,3 3,51 29,01 21/15 3,0 5,3 4,61 33,62 15/10 3,0 12,2 9,44 43,06 10/7 2,0 12,0 9,00 52,06 7/5 2,2 4,0 3,46 55,50 5/2,5 0,8 24,5 17,39 72,91 2,5/2,5 15,0 10,5 83,40 1,5/0,5 18,0 12,6 96,00 < 0,5 5,7 4,0 100,00 Tabelle 5 Gewicht in Abhängigkeit von der Korngrößenverteilung für zwei konventionell gemahlene Proben und für eine Mischung 10 %A/90 %B (E) d (µm) Probe A Probe B Probe E 10%A/90%B Probe E Ausbeute unter d(µm),Gew.-% Gew.-% zwischen d (µm) > 500 0 0,14 500/315 1,4 2,61 0,14 315/200 26,1 1,65 2,75 200/125 16,5 1,17 4,40 125/90 11,7 1,19 5,57 90/69 11,9 1,09 6,76 63/45 10,9 0,65 7,85 45/32 6,5 3,37 8,50 27/21 4,0 3,3 5,07 11,90 21/15 3,0 5,3 11,30 16,94 15/10 3,0 12,2 11,00 28,30 10/7 2,0 12,0 3,88 39,20 7/5 2,2 4,0 22,13 43,12 5/2,5 0,8 24,5 13,50 65,25 2,5/2,5 15,0 16,20 78,75 1,5/0,5 18,0 5,10 94,95 < 0,5 5,7 100,00

In summary, it can be stated that the use of the grain fraction according to the invention, which does not correspond to a normal distribution, as a catalyst or additive in a bubble column reactor minimizes the total amount to be added while operating conditions are favorable. These do not correspond to a normal distribution Grain size distributions can be achieved in two different ways:

• a) by mixing two or more different particle size distributions corresponding to a normal distribution at any stage of the catalyst preparation, the mixture being characterized by R² <0.96 or
• b) by the separate addition of two or more particle size distributions (R² 7 0.97) at any point in the reaction system before or at the inlet of the hydrocracking reactor.

Table 1 Weight depending on the grain size distribution for a conventional sample after grinding (A) d (µm) Sample A% by weight between d (µm) Sample A% by weight below d (µm) > 500 0 500/315 1.4 1.4 315/200 26.1 27.5 200/125 16.5 44.0 125/90 11.7 55.7 90/69 11.9 67.6 63/45 10.9 78.5 45/32 6.5 85.0 27/21 4.0 89.0 21/15 3.0 92.0 15/10 3.0 95.0 0/7 2.0 97.0 7/5 2.2 99.2 5 / 2.5 0.8 100.0 2.5 / 1.5 - - 1.5 / 0.5 - - <0.5 - - Weight depending on the grain size distribution for a conventional sample after grinding (B) d (µm) Sample B% by weight between d (µm) Sample B% by weight below d (µm) > 500 500/315 315/200 200/125 125/90 90/69 63/45 45/32 27/21 3.3 3.3 21/15 5.3 8.6 15/10 12.2 20.8 10/7 12.0 32.8 7/5 4.0 36.8 5 / 2.5 24.5 61.3 2.5 / 1.5 15.0 76.3 1.5 / 0.5 18.0 94.3 <0.5 5.7 100.0 Weight depending on the grain size distribution for two conventionally ground samples and for a mixture 50% A / 50% B (C) d (µm) Sample A Sample B Sample C Sample C Yield below d (µm),% by weight % By weight between d (µm) > 500 0 500/315 1.4 0.7 0.7 315/200 26.1 13.0 13.7 200/125 16.5 8.3 22.0 125/90 11.7 5.9 27.9 90/69 11.9 6.0 33.9 63/45 10.9 5.5 39.4 45/32 6.5 3.2 42.6 27/21 4.0 3.3 3.2 45.8 21/15 3.0 5.3 4.2 50.0 15/10 3.0 12.2 7.7 57.7 10/7 2.0 12.0 7.0 64.7 7/5 2.2 4.0 3.1 67.8 5 / 2.5 0.8 24.5 12.7 80.5 2.5 / 2.5 15.0 7.5 88.0 1.5 / 0.5 18.0 9.0 97.0 <0.5 5.7 2.9 99.9 Weight depending on the grain size distribution for two conventionally ground samples and for a mixture 30% A / 70% B (D) d (µm) Sample A Sample B Sample D 30% A / 7% B Sample D Yield below d (µm),% by weight % By weight between d (µm) > 500 0 0 500/315 1.4 0.42 0.42 315/200 26.1 7.83 8.25 200/125 16.5 4.95 13.20 125/90 11.7 3.51 16.71 90/69 11.9 3.57 20.28 63/45 10.9 3.27 23.55 45/32 6.5 1.95 25.50 27/21 4.0 3.3 3.51 29.01 21/15 3.0 5.3 4.61 33.62 15/10 3.0 12.2 9.44 43.06 10/7 2.0 12.0 9.00 52.06 7/5 2.2 4.0 3.46 55.50 5 / 2.5 0.8 24.5 17.39 72.91 2.5 / 2.5 15.0 10.5 83.40 1.5 / 0.5 18.0 12.6 96.00 <0.5 5.7 4.0 100.00 Weight depending on the grain size distribution for two conventionally ground samples and for a mixture 10% A / 90% B (E) d (µm) Sample A Sample B Sample E 10% A / 90% B Sample E Yield below d (µm),% by weight % By weight between d (µm) > 500 0 0.14 500/315 1.4 2.61 0.14 315/200 26.1 1.65 2.75 200/125 16.5 1.17 4.40 125/90 11.7 1.19 5.57 90/69 11.9 1.09 6.76 63/45 10.9 0.65 7.85 45/32 6.5 3.37 8.50 27/21 4.0 3.3 5.07 11.90 21/15 3.0 5.3 11.30 16.94 15/10 3.0 12.2 11.00 28.30 10/7 2.0 12.0 3.88 39.20 7/5 2.2 4.0 22.13 43.12 5 / 2.5 0.8 24.5 13.50 65.25 2.5 / 2.5 15.0 16.20 78.75 1.5 / 0.5 18.0 5.10 94.95 <0.5 5.7 100.00

Claims (12)

Process for the hydrogenative conversion of heavy and residue oils, waste and waste oils, tar sands and the like. Like. With contents of heavy metals (V + Ni) of 200 ppm or more, asphaltenes of 2 wt .-% or more, Conradson coal of 5 wt .-% or more and a density of less than 20 ° API, which with a catalyst or additive or a mixture thereof from the group red mud, Fe₂O₃, iron ores, hard coal, lignite, hard coal coke, brown coal coke, preferably impregnated with heavy metal salts, activated carbon, carbon blacks of the gasification of solid or liquid fuels, cokes from hydrogenation or distillation residues are contacted with Hydrogen at a hydrogen partial pressure between 50 and 300 bar, a temperature between 300 and 500 ° C, a throughput between 0.1 to 5 t / m³h, a gas / liquid ratio between 100 and 10000 Nm ^{3 /} t, gas velocities of 3 cm / s or higher and a catalyst or additive concentration of 0.1 to 10% by weight in a bottom phase reactor system through which the bottom flows upwards, characterized in that the catalyst or additive additive has a particle size distribution between 0.1 and 2000 μm, preferably 0.1 and 1000 μm, and the proportion of the catalyst or additive particles with a particle size of 100 μm or more is between 10 and 40% by weight, preferably 10 or 30% by weight of the total amount of catalyst or additive added to the reactor system. A method according to claim 1, characterized in that the catalyst or the additive is composed of two or more particle size distributions from two or more grindings of the catalyst or additive which are mixed before use and that the said two or more particle size fractions only by one of A straight line deviating curve can be reproduced if one enters its cumulative weight distribution against the particle size in a double logarithmic log (-log) / log coordinate system, whereby for the indicated graphical representation of the mixture obtained it applies that the correlation coefficient R² is a value for a calculated straight line less than 0.96. Method according to Claim 1 or 2, characterized in that one or a system comprising a plurality of bubble column columns (s) with a flow from bottom to top is provided. Method according to at least one of the preceding claims, characterized in that a gas phase reactor is provided for the purpose of hydrodesulfurization of the distillates. Process according to at least one of the preceding claims, characterized in that the catalyst or the additive with two or three different particle size distributions is added by means of two or three separate and independent metering systems, part of the catalyst or additive being a fine grain fraction with a particle size of 100 µm or less and the other part with a particle size between 50 and 2000 µm, preferably 150 and 1000 µm are each added separately. Process according to at least one of the preceding claims, characterized in that the coarse grain fraction contains a proportion of 0.0 to 70% by weight, preferably less than 50% by weight, of fine particles with a particle size of at most 100 µm. Process according to at least one of the preceding claims, characterized in that the proportion of the coarse grain fraction is 20% by weight or more, based on the total amount of the catalyst or additive used. Process according to at least one of Claims 1 to 6, characterized in that the proportion of the coarse grain fraction is 20% by weight and in the subsequent operating period is at least 5% by weight of the amount of catalyst or additive. Method according to at least one of claims 1 to 6, characterized in that the coarse grain fraction is added only when starting up or discontinuously in the course of the operating period. Method according to at least one of the preceding claims, characterized in that brown coal or hard coal is added in a weight ratio of the feed oil or oil-containing feed product of 5: 1 to 1: 1.5, the proportion of the coal, the proportion of the coarse grain fraction with a Grain size of 100 microns or more corresponds, grain sizes of at least 100 microns to 2000 microns. Method according to at least one of claims 1 to 9, characterized in that the fine grain fraction used as additive and the coarse grain fraction do not consist of the same material, in which case the following combinations are preferred: Fine grain fraction Coarse grain fraction Red mud Coal soot ground brown coal ground brown coal ground brown coal natural materials containing iron Bituminous coal or ground brown coal natural inorganic materials containing iron natural inorganic materials containing iron natural inorganic materials containing iron Hard coal or petroleum coke natural inorganic materials containing iron Soot from gasification processes Process according to at least one of Claims 1 to 9, characterized in that calcium or magnesium compounds are used as the coarse grain fraction to improve the further utilization of the hydrogenation residue.

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