JPS61209295A - Conntinuous conversion of hydrocarbon - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a process for the continuous conversion of hydrocarbons, more particularly to a process for the hydro-reforming of hydrocarbons in the temperature range from 480 to 600°C and in the presence of catalysts, i.e. aromatic A process for the production of hydrocarbons, comprising: passing an initial charge of hydrocarbons and hydrogen through at least two reaction zones in series, each of the fluidized bed type; The catalyst flows through each of the reaction zones in succession, also in the form of a fluidized bed, through each of them in succession from top to bottom, until the last reaction zone through which the charge has passed passes. It concerns a method in which the catalyst continuously removed from the lower part is sent into a regeneration zone.

PRIOR ART AND ITS PROBLEMS In the prior art, the regenerated catalyst is subjected to a reduction treatment, i.e., in order to reduce certain oxides, especially metal oxides, present in the catalyst before reaching the first reaction zone. If so, it will be treated with hydrogen.

In the prior art, when operating in the reaction zone of the catalyst bed, the reduction is carried out at the head of the reactor, inside the reactor, or near the head of the reactor.

Heating of the reaction in the reduction zone is ensured by heating means of the reactor itself, in particular by indirect contact with the hot charge to be treated.

Once the reduction is complete, the catalyst reaches the proper reaction zone.

In the same prior art, the regenerated and reduced catalyst is generally subjected to a sulphidation treatment before reaching the original reaction zone, during which all the metals of the catalyst are sulphurized to a significant extent. The sulfurization reaction takes place in the am of the reactor, either in the same zone where the reduction takes place or in a zone just below the reduction zone. In the sulfide zone, in the conventional technology, the temperature required for the reduction, i.e. 480
The operation is carried out at temperatures between 600°C and 600°C.

The sulfiding agent used is alternatively pure hydrogen sulfide or hydrogen sulfide diluted with hydrocarbon gas, or alternatively dimethyl disulfide diluted with hydrogen or other sulfur compounds such as alkyl sulfides or alkyl mercaptans diluted with hydrogen. It is. The pressure used will be that within the reforming reactor or aromatic hydrocarbon production reactor, and the duration of the sulfurization reaction will vary from a few minutes to several days depending on the operating conditions selected.

Conventional Example 1 FIG. 3 does not belong to the present invention, but illustrates one method in the prior art.

In FIG. 3, three reactors are used.

The charge is led to the first reactor (29) through the conduit (1), the furnace (2) and the channel (3). First reactor (29)
The effluent from the furnace (30) is removed by a conduit (30).
7) and through conduit (38) to the second reactor (42). The effluent from the second reactor (42) is transferred to the conduit (
43), the tract (50) and the conduit (51)
through which it is sent to the third reactor (55). The effluent from the third reactor (55) is removed by a conduit (56). Unused catalyst is introduced into the first reactor (29), for example via conduit (4), upon start-up of the unit. The regenerated catalyst is transferred to the first reactor (2) by a conduit or lift (19) and a plurality of conduits (27) (28).
9) Get into it. The catalyst follows conduit (27028) into contact zone (22). This process takes place in the form of a fluidized bed.

The catalyst is removed from the first reactor (29) by a plurality of conduits (31, 32) as well as a conduit (33) which brings the catalyst to the lift bot (34). This extraction is
This can be done periodically by means of a suitable gate valve system, or even better, continuously without a gate valve system.

At that time, the catalyst flow rate is adjusted using the lift pot (3
4) is secured by classical means by pure hydrogen injected by conduits not shown or by the force of hydrogen generated within the unit.

The gas flow rate of the unit is adjusted to prevent part of the reaction effluent from being carried away with the catalyst particles. The catalyst is then conveyed from the lift pot (34) to the second reactor (42) by any known lifting and unloading device, herein referred to by the word "lift". The fluid in the lift (36) may be recycled hydrogen, ie hydrogen produced by the unit, introduced through the conduit (35).

The catalyst thus transported into the lift (36) reaches the receiver (39) and from there a plurality of conduits (40) (4
1) to reach the second reactor (42).

Here, the receiver (39) and the conduits (40) (41) are
Depending on the case, it may constitute a part of the second reaction device (42). In other words, it may be provided within the second reaction device (42).

The catalyst passes through a second reactor (42) in the form of a fluidized bed;
As for the first reactor (29), a plurality of conduits (
44) (45) from the second reactor (42) and by conduit (46) to the lift port (47).
reach. For example, a lift (49) receiving a supply of recycled hydrogen, i.e. hydrogen of the unit, coming through a conduit (48).
The catalyst then reaches the receiver (52) and from there via a plurality of conduits (53, 54) to the first reactor I (55) of the fluidized bed. The catalyst is supplied to the first and second reactors (
29) Similar to (42), multiple conduits (57
) (58) from the third reactor (55).

This spent catalyst reaches the lift pot (60) by conduit (59). This spent catalyst is then transferred to an "accumulator decanter" flask (γ), for example by means of a lift (6) fed with recycled hydrogen which is fed by a conduit (61) into a lift pot (60).
sent to. The spent catalyst reaches the regeneration zone (10) through a gate valve system (8) and a conduit (5H9).

After catalyst regeneration is complete and the regenerated catalyst is purged to remove molecular oxygen (the various feed conduits required for regeneration and purging are conventional and are not shown): This regenerated catalyst is passed through the channels (11, 13) and the gate valve system (12) to the flask (15).
sent to. Therein, in some cases, the regenerated catalyst is partially regenerated by a stream of pure hydrogen fed through the conduit (14) for the purpose of maintaining a mildly high pressure in the flask (15) relative to the lift pot (17). do.

Therefore, guide! ! The catalyst removed from the flask (15) by (1B) reaches the lift pot (17) from where it is pumped with pure hydrogen via conduit (18).
The reduction zone (2
0) is carried to the lift (19).

The reduction zone (20) is optionally connected to a conduit (
21) Receive the supply of hydrogen sent from. The catalyst is
It flows in the form of a fluidized bed through the reduction zone (20). Then,
The catalyst is connected to the reduction zone (20
), but also in these conduits flows in the form of a fluidized bed of catalyst.

The sulfurization of the catalyst with a gas containing sulfur compounds or optionally with pure hydrogen □ used as carrier gas for the sulfur compounds is carried out in the conduit or leg (27) (
28). This sulfur-containing gas is passed through the conduit (24
) (25) and (26) by conduit (27) (28)
Guided within. The gas turbulence in the conduits or legs (27, 28) is very strong, thus ensuring a smooth sulfurization reaction.

Generally, conduits (27) (28) are filled with catalyst, sulfur-containing gas and an excess of hydrogen in conduits (18), (19), and (21), so that excess pure hydrogen is removed by discharge conduit (23). There is a need to. The reduced and sulphurized regenerated catalyst then enters the actual contact zone (22) through conduits (27) and (28).

Problems with Conventional rI41 In Figure 3, reduction and sulfidation occur in the first reactor (29
), i.e., in the upper part of the inside of this reactor (29), the reduction and sulfurization temperature is either the temperature of the reactor itself, i.e., the reforming temperature (480°C or higher) or the temperature of aromatic hydrocarbon production ( Preferably 5
20°C or higher). However, since the reactor exhibits extremely large thermal inertia,
There is in any case no way to rapidly vary the temperature in the upper part of the first reactor (29).

Therefore, from this fact, it is impossible to accurately control the reduction temperature and the sulfidation temperature, since the reduction temperature and the sulfidation temperature are practically equal to the temperature at which the reforming reaction or the aromatic hydrocarbon production reaction takes place. Therefore, in the method carried out according to FIG.
There is room for improvement in this process, as it has been recognized that it is desirable to operate at moderate temperatures in the range of 0.000 to 390.degree.

Conventional Example 2 Recently, in Japanese Patent Application Laid-Open No. 53-90303, the arrangement shown in FIG. 4 was proposed, although it is not based on the present invention. According to this, the two reactions, reduction and sulfidation, are carried out separately on the one hand, and outside the reactor on the other hand.

In FIG. 4, three reactors are also used. The charge is led to the first reactor (29) through the conduit (1), the furnace (2), and the channels (3) and (4). First reaction device (
Effluent from 29) is removed by conduit (30);
The second reactor (4) passes through the furnace (37) and the conduit (38).
2). First reactor! The effluent from (42) is removed by conduit (43) and sent through the furnace (50) and conduit (51) to the third reactor (55). The most effluent is removed from the M3 reactor (55) by conduit (56).

Unused catalyst is introduced into the first reactor (29) by a conduit not shown in FIG. 4 upon start-up of the unit. The regenerated catalyst is transferred to the first reactor (2) by a conduit or lift (19) as well as a plurality of conduits (27028).
9) Get into it. The catalyst is in the form of a fluidized bed on the one hand in a conduit (
27) (2B) and on the other hand the first reactor (29)
Go inside.

The catalyst passes through the three reactors (29) (42) (55) of FIG. 4 as described with respect to FIG.

The catalyst is connected to the conduits (31) (32), conduit (33), lift and
It passes sequentially through the pot (34) and the lift (36). The fluid of the lift (36) is admitted through the conduit (35). Thus, the catalyst is connected to a plurality of conduits (40) (41)
through to and through a second reactor (42);
This second reactor (42) is connected by conduits (44) (45).
) and passes through the conduit (46) to the lift pot (47). The catalyst is transferred to the receiver (52) by means of a lift (49) in which the carrier fluid is admitted through the conduit (48).
), the conduit (53H54), the third reactor (55)
as well as through conduits (57), (58) and then conduit (59). The spent catalyst removed from the first reactor I (55) by conduit (59) thus reaches the lift pot (60), from where it is fed with recycled hydrogen introduced through conduit (61). [Accumulator Decanter] flask (7) by receiving lift (6)
sent to.

The spent catalyst is also removed from the gate valve system (8) and the conduit (
9) and reaches the regeneration zone (10). regenerate the catalyst,
After purging the regenerated catalyst to remove molecular oxygen,
This regenerated catalyst is sent to the reduction zone (20) just as in FIG. The various supply lines required for regeneration and purging are conventional and not shown.

The regenerated catalyst is connected to the flow path (11) (13), gate valve system (
12) and the receiver flow through the flask (15),
The receiver is a flask (15), and in some cases a conduit (14)
It is scavenged by a stream of pure hydrogen introduced through it. The catalyst is removed from the receiver flask (15) by conduit (16) and reaches the lift pot (17), from where it is lifted by pure hydrogen introduced by conduit (18).
19). The catalyst thus reaches the reduction zone (2G).

The difference from Figure 3 is that in Figure 4, the reduction zone (20)
is located above the first reactor (29) rather than at the inner upper part of the first reactor (29). The reduction zone (20) is optionally supplied with pure hydrogen introduced by the conduit (21) if it is confirmed that the pure hydrogen in the lift (19) is not sufficient to carry out this reduction. The reduction zone (20) is, for example, a conduit (5) (2
2) by indirect contact with a portion of the charge. The split portion of the charge serving to heat the reduction zone (20) is then generally routed directly to one of the two reactors (42) (55).

The catalyst then passes through a plurality of conduits (27) (28).
It is taken out from the reduction zone (20). In these conduits or [legs J (27028), in other words the first reactor M
External to (29), the sulfurization of the catalyst takes place with sulfur compounds, optionally carried in pure hydrogen. This sulfur-containing gas passes through the conduit (24) (25N26).
7) Introduced in (28). Excess hydrogen is removed from the conduit (23
) is retrieved by The catalyst is then transferred to the first reactor (
29) Go inside.

Problems with Conventional Example 2 According to the method shown in FIG. 4, reduction can be carried out at a slightly more moderate temperature than in FIG. However, the reduction temperature is still excessively high, generally 530
℃ or higher. This is because reforming reactions and aromatic hydrocarbon production reactions generally require a temperature of at least 540°C, and the method shown in Figure 4 is ultimately just a variation of the method shown in Figure 3. .

Due to the fact that the high temperature of the reduction reaction and the high temperature of the reaction zone,
Also, because of the heat conductivity of the legs (27) (28), the scheme of FIG. 4 does not make it possible to obtain much more moderate temperatures than in FIG. In effect, therefore, the sulfiding temperature is as excessive as in FIG. 3, where it is forced to the temperature of the reactor.

Therefore, the system of FIG. 4 is not satisfactory because it has the same serious problems as the system of FIG. (a) First of all, since each reaction zone exhibits extremely large thermal inertia, e.g.
Even if the reference numeral (201) in the figure is placed outside the first reactor (29) in FIG. 4, there is no way to rapidly change the temperature of this part (20). In fact, in FIG. 4, since the reduction temperature and the sulfidation temperature are equal to the temperatures at which the reforming reaction and the aromatic hydrocarbon production reaction take place, it is impossible to properly adjust either the reduction temperature or the sulfidation temperature.

(b) Secondly, due to the fact of the thermal inertia of the upper part of the first reactor (29) or of the parts adjacent to this reactor, the sulfurization temperature is virtually always the temperature at which the reduction takes place, i.e. 480°C.
The result is as follows. However, in order for this sulfurization to be more effective, in other words, for sulfur to be more firmly fixed on the metal of the catalyst, it is desirable that the sulfurization temperature be 400° C. or lower. The ideal sulfiding temperature is 390℃
Or it will be below 380°C.

(c) Furthermore, safety conditions are still not sufficient in the systems shown in FIGS. 3 and 4. In fact, by purging the catalyst with nitrogen following its regeneration, it is possible to remove all the oxygen gas that has acted on it during the course of the regeneration, thus avoiding the risk of explosion in the reduction zone. However, if an explosion were to occur suddenly due to unspecified causes such as high pressure or accidental leakage, it would immediately propagate into the sulfidation zone and the reforming reaction zone or the aromatic hydrocarbon production reaction zone. This is because the reduction, sulfidation and reaction zones are in close proximity to each other.

According to the water droplet according to the present invention, it is possible to prevent these problems. In the water droplet, on the one hand, the hydrogen treatment zone and the sulphidation zone are distinct from each other, and on the other hand, both are located at a distinct distance from the first reactor.

SUMMARY OF THE INVENTION The present invention is a process for reforming hydrocarbons or producing aromatic hydrocarbons in the temperature range of 480 to 600° C. and in the presence of a catalyst, in which the original composition of hydrocarbons and hydrogen is The charge is passed through at least two reaction zones conveyed in series and each of the fluidized bed type, the charge passing through each reaction zone in turn and the catalyst also flowing through each of the reaction zones in the form of a fluidized bed. A method in which the catalyst flows continuously from the top to the bottom through each reaction zone in turn, and the catalyst continuously taken out from the bottom of the last reaction zone through which the charge has passed is sent into the regeneration zone. , - the regenerated catalyst descends into a hydrotreating zone that is separate from the reaction zone, in which it is hydrotreated at a temperature below 450° C. in order to undergo partial reduction; The regenerated and hydrotreated catalyst is continuously passed down through a first enclosure into which a sulfur compound is injected; flows continuously from said first enclosure into a second enclosure located above and distinct from the first reaction zone through which the charge passes, and then passes through the catalyst. flows continuously from the second enclosure into the first reaction zone, and the regenerated and hydrotreated catalyst is continuously flowed from the first enclosure to the first reaction zone. , the method is characterized in that it undergoes sulfidation carried out in the temperature range from 200 to 390° C. with the force of a sulfur compound injected into said first zone.

The object of the present invention is a process in which the catalyst, after being regenerated, undergoes treatment with hydrogen and sulfidation in two distinct zones clearly separated from the reaction zone. Thus, the water droplet allows hydrogen treatment and sulfurization to be carried out at moderately ideal temperatures, which are significantly lower than those used in the prior art. In the prior art, the hydrotreating and sulfiding zones are located in close proximity to the reaction zone, so that the hydrotreating and sulfiding temperatures are effectively limited to the reaction zone temperatures.

The present invention relates to a hydrocarbon reforming process. The invention also provides starting from unsaturated or unsaturated gasolines (e.g. pyrolysis gasolines, in particular steam cracking gasolines, or catalytically reformed gasolines);
It also concerns the production of aromatic hydrocarbons, such as benzene, toluene and ortho, meta or xylenes, starting from naphthenic hydrocarbons which can be converted into aromatic hydrocarbons by dehydrogenation.

In the water droplet, at least two reactors or reaction zones, preferably three to four reactors or reaction zones, are used to carry out the reforming reaction, that is, the reaction for producing aromatic hydrocarbons. Each contains a fluidized bed of catalyst.

The charge flows sequentially through each reactor or reaction zone according to an axial or radial (ie, from the center to the periphery or from the periphery to the center) flow.

The reaction zones are heated intermediately between each zone;
They are arranged in series, eg, side by side, or vertically stacked, so as to flow through each of these reaction zones in turn.

The new catalyst is placed at the top of the first reaction zone which receives the new charge. The catalyst then flows continuously from the top to the bottom of this zone, from which it is continuously removed and conveyed by any suitable method (particularly lift) to the top of the next reaction zone, where it is Flows in the same way from the top to the bottom, and so on until the last reaction zone,
In its lower part it is continuously removed and then sent to the regeneration zone.

It is desirable to arrange the reaction zones side by side.

Flow of catalyst from the bottom of one reaction zone to the top of another reaction zone, and from the bottom of the last reaction zone to the regeneration zone, and in some cases, from the bottom of the regeneration zone to the top of the first reaction zone. The flow to the top takes place using any known lifting device, designated herein with the word "lift". The lift fluid used to deliver the catalyst may be any suitable gas, such as nitrogen, pure or purified hydrogen, or hydrogen produced within the system.

The solids transferred from reaction zone to reaction zone and to regeneration zone may be, for example, particulate catalyst.

The catalyst may, for example, be spherical with a diameter generally comprised between 1 and 3-1, preferably between 1.5 and 2-1.

However, these numbers are not limiting.

Generally the specific weight of the catalyst is between 0.4 and 1, or 0.
．． It is between 5 and 0.9, specifically between 0.55 and 0.8. However, these numerical values are not limited.

The reactions to which the method according to the invention is preferably applied are those listed at the beginning of this specification, and can clearly be divided into the following two groups: (1) One of them is a reforming reaction.

The general conditions for the catalytic reforming reaction are as follows. That is, the average temperature in each reaction zone is approximately 480 to 6
00°C, or in the range of 530 to 600°C, the pressure is in the range of about 5 to 20 kg/all, the speed is in the range of 0°5 to 10 volumes of liquid naphtha per 1 volume of catalyst, and the recirculation rate is ranges from 1 to 10 moles of hydrogen per mole of charge.

Specific examples of rehoming reactions include the following.

Charge: naphtha that leaches in the range of about 60 to 220°C,
Particularly single-capture naphtha.

Catalyst: The catalyst comprises at least one metal of the platinum group, reduced to one of the noble metals such as platinum, palladium, iridium, ruthenium, osmium, supported on a support of alumina or equivalent compounds. (e.g. platinum-alumina-halogen or platinum-iridium-alumina-halogen), the content of noble metal is 0.1 to 2% by weight based on the catalyst, and the content of halogen, preferably chlorine or fluorine, is 0.1 to 10% by weight. %. The alumina-halogen combination can be replaced with other supports, such as silica-alumina. The catalyst may also include at least one metal promoter selected from Group 8 of the Periodic Table of Elements.

(2) The other one is the production reaction of aromatic hydrocarbons from saturated or unsaturated gasoline.

If the charge is unsaturated and contains diolefins and monoolefins upon reduction, they must first be removed by selective or total hydrogenation.

If the charge contains olefins, the charge from which all of its olefins and a significant amount of monoolefins have been removed by hydrogenation, if necessary, is then treated in each reaction zone with at least one acidic carrier. at about 500 to 600°C in the presence of hydrogen and a catalyst containing one kind of metal, for example, one kind of noble metal of group Ⅰ (platinum group) and/or at least one kind of metal co-catalyst appropriately selected from the periodic table of elements. or a temperature in the range of 520 to 620°C, 1 to 60K
Under a pressure in the range of f/aI, the volumetric flow rate of the liquid charge per hour is about 0.1 to 10 times the volume of the catalyst,
The aromatic hydrocarbon production reaction is carried out at a hydrogen/hydrocarbon (molar ratio) of about 0.5 to 20.

Regeneration of the original catalyst can be carried out using known methods. Preferably, the catalyst is combusted with the aid of (a) a gas containing molecular oxygen;

(b) Oxychlorination using a gas containing molecular oxygen and simultaneously using a halogen or a halogen compound, such as hydrohalic acid or an alkyl halide.

(c) Perform final treatment with a gas containing molecular oxygen.

These three treatments may be carried out sequentially, either in a single fixed bed zone or within the confines of a fluidized bed, with the catalyst successively entering distinct zones in which these three steps of regeneration take place. .

Regeneration involves purging, for example with nitrogen, to remove any traces of residual oxygen gas from the catalyst.

Generally, the catalyst is in the form of a fixed bed or a fluidized bed, e.g.
Preferably in the form of a fluidized bed, it undergoes this hydrogen treatment during the rather long time required to pass through the enclosure (15). When the hydrogen treatment is carried out between 380 and 445°C, the sulfidation is carried out at a temperature below the hydrogen treatment temperature, in particular at a temperature about 50°C lower than the hydrogen treatment temperature, so that the sulfidation temperature is preferably 260°C. No〒390℃, more details 280℃
It is included between 300°C and 300°C. Hydrogen treatment is 150 to 2
When carried out between 00°C, the sulfiding temperature is preferably 20°C.
Included between 0 and 390°C.

Catalysts suitable for this hydrogen treatment at temperatures below 450° C. are in particular catalysts containing an alumina support and a critical content of various suitable metallic elements (metals or metal compounds). Specific catalysts for the reforming reaction include, by weight relative to the alumina support, the following:

(a) a first metal O12 to 0.4% selected from platinum, iridium, ruthenium and rhodium; (b) a second metal different from the first metal and selected from iridium and rhodium; 0°02 to 0.0
(c) 0.25 to 0.55% of at least one third metal selected from copper, silver, gold, titanium, niobium, indium, thallium, manganese, germanium, tin, lead, and rhenium. , (d) One type of halogen, such as chlorine or fluorine, in an amount of O31 to 10%.

A specific catalyst for aromatization reaction (aromatic hydrocarbon production reaction) contains the following in terms of weight relative to the alumina support.

(a) a first metal selected from among platinum, iridium and rhodium; (b) different from the first metal and selected from among iridium, rhodium, ruthenium, palladium and osmium; 0.03 to 0.05% of the selected second metal or 0.05% of rhenium.
(c) 0.02 to 0.09045% of a third metal selected from copper, silver and gold; or 0.02 to 0.09045% of manganese;
1 to 0.12%, or titanium, niobium, thallium,
0.2 to 0.3% of one metal selected from cadmium and indium; (d) 0.2 to 0.3% of one halogen, such as chlorine or fluorine;
1 to 10%, but optionally also a fourth metal element, i.e. (e) 0.1 to 0.04%, preferably O9
2 to 0.3%.

Functions and Effects of the Invention Since the method for continuous conversion of hydrocarbons according to the present invention is configured as described above, the following effects are achieved.

First, the method of the present invention allows hydrogen treatment and sulfidation to be carried out at moderately ideal temperatures, which are significantly lower than those used in the prior art.

More specifically, in these two zones, hydrotreating and sulfiding, thermal inertia no longer exists and the temperature in the hydrotreating zone (e.g. by diversion of a portion of the charge) and the temperature in the sulfiding zone is as desired. The values can be easily and independently adjusted.

In particular, the hydrogen treatment temperature can be adjusted to an optimum temperature, generally below 450°C. Similarly, whereas in the prior art the sulfiding zone was located between two high temperature zones, namely the reduction zone and the reactor, it was not possible to reduce the temperature of the sulfiding zone; In the method, sulfurization is
It has become particularly easy to perform at temperatures between 390°C and 390°C.

Additionally, the hydrogen treatment zone and sulfidation zone are located at a distance from the reaction zone, so even if an explosion were to occur in the hydrogen treatment zone, this would surely prevent it from propagating to the reaction zone and causing a major accident. I can do it.

More specifically, in the water droplet according to the present invention, even if the original regeneration of the catalyst was followed by a purge, traces of oxygen were still present in the regenerated catalyst and it happened that the hydrogen treatment joint Even if an explosion were to occur inside, this explosion would not spread into the first reactor, which here is completely separate from the hydrogen treatment zone.

Miizuki is characterized by hydrogen treatment at extremely low temperatures. In fact, it has been found to be particularly advantageous if the reduction of the regenerated catalyst is carried out at a temperature below 450°C, preferably in the range from 380 to 440°C. temperatures much lower than this, e.g. preferably between 150 and 290°C
It is possible to operate even at temperatures between.

Strictly speaking, this is no longer a complete reduction reaction since the temperature is not high enough. Rather, it is a hydrogen treatment of the catalyst at moderate temperatures that ensures a partial reduction, ie, an incomplete but sufficient reduction to obtain effective action of the catalyst.

Hydrotreating the catalysts carried out in this way can, for certain catalysts, be as effective as reducing these catalysts at temperatures equal to or above 480°C, with regard to the duration of their lifetime and especially their stability. was found to be effective.

This hydrogen treatment according to the invention at temperatures below 450° C. can thus be used for reforming reactions or for the production of aromatic hydrocarbons, especially benzene of very high purity (the so-called "aromatization" reaction). It has been found that it is particularly effective as a catalyst.

EXAMPLES Example 1 Various arrangements are possible for carrying out the method according to the invention. FIG. 1 first illustrates one method for implementing the invention.

In FIG. 1, only the main parts are shown.

In FIG. 1, no external heat supplementation is necessary to obtain the desired temperature in the lower zone (26), which is the hydrogen treatment zone. Excess hydrogen after hydrogen treatment can be removed by means of a discharge pipe (14a). Note that other symbols in FIG. 1 have the same meanings as in FIG. 3.

If the operation is carried out according to Figure 1, the sulfurization will be from 26O to 39
It is very easy to carry out at temperatures of 0°C or between 200 and 390°C.

For example, when the temperature of hydrogen treatment is between 380 and 445°C, in the upstream lower zone (26), the
To reduce the temperature from 445°C by at least 50°C, the lift pot (17) must not be heated or the lift pot (17) and/or the conduit (16) and/or the lift (19) and/or Legs (27) (28
), it is sufficient to provide appropriate insulation or heat transfer. It also depends not only on the heat loss of the lift pot (17) or the lift (19) itself or the legs (27) (28), but also on the conduit (
Adjustment of the sulfurization temperature can also be carried out depending wholly or partly on the temperature of the hydrogen introduced into the lift (19) through 18). Hydrogen treatment temperature is 15
If it is between 0 and 290℃, this temperature is
7) Maintain up to position (28) or e.g.
The hydrogen admitted through conduit (18) is heated to raise the temperature of the sulphide zone.

One advantage of operating at regenerated catalyst hydrotreating temperatures below 450°C according to Figure 1 is that traces of oxygen remain in the regenerated catalyst despite the original regeneration followed by purging; Even if there is a risk of an explosion occurring in the lower zone (26), this lower zone (26) is not at ^ temperature, so the possibility of an explosion is reduced, and even if an explosion occurs suddenly, the first reactor (29) is far away from the hydrogen treatment zone so that the explosion cannot spread into the first reactor (29).

Similarly, it is very easy to control the temperature in the hydrotreating zone or in the sulfiding zone if necessary.

This was not so easy in the prior art (FIGS. 3 and 4), where the reduction zone was located at or near the top of the reactor.

From the above, it follows that the operating conditions of the entire unit are extremely safe.

With the arrangement of FIGS. 3 and 4, it is not possible to operate according to the invention, ie to carry out hydrotreating of the regenerated catalyst at temperatures below 450.degree.

In fact, it can be seen that in the method shown in FIG. 3, there is no means to lower both the reduction temperature and the sulfurization temperature to 480° C. or lower. Figure 4 is compatible with high altitude rigor, but at 450℃
The reduction zone (20
) would be a difficult problem to control. Even if the reduction zone (20) is not heated and the lift (19) is suitably insulated, the loss of heat is such that the catalyst coming out of the regeneration zone (10) reaches the reduction zone (20) at temperatures of up to 500°C. When the temperature is reached, the maximum temperature will be 360 to 370°C. Therefore, it is now necessary to heat the reduction zone (20) again, which requires an uneconomical supply of heat.

In contrast, if the catalyst is heated at temperatures up to 500°C in the regeneration zone (1
In the method of FIG. 1, the conduit (11
) (13) as well as in the gate valve (12) is such that the enclosure (15) reaches the desired temperature below 450°C. This allows for energy gains.

Moreover, the method of FIG. 1 makes it possible to obtain new advantages as follows.

That is, in FIGS. 3 and 4, it was absolutely necessary not to use the hydrogen in the unit in the lift (19). In fact, with the hydrogen in the unit, the catalyst always has a tendency to catalyze the side reaction of hydrocracking due to the very low temperature hydrocarbons that the hydrogen in the unit may contain.

However, in the method shown in Figure 1, the sedation zone of the lift (19) does not exist between two extremely high temperature zones, but rather between the lower zone (26), which is a relatively low temperature zone, and the high temperature first reaction zone. and the device (29). If this is added to the fact that in the lift (19) the sulfurization takes place at temperatures below 390°C, it follows that in the process according to the invention there are no zones where side reactions of hydrocracking may occur. It follows that the temperature is insufficient for this type of reaction to take place. Nevertheless, the result is that it is possible to inject hydrogen within the unit rather than pure hydrogen into the conduit (18) of Figure 1, although it is not recommended to operate in this manner permanently. become. This is something that is excluded in the prior art. Similarly, if the hydrogen treatment temperature is fairly low (150-290°C), conduit (14) and enclosure 1 in Figure 1! In (15) it is possible to use hydrogen within the unit.

This use of hydrogen in the unit in conduit (18), optionally in conduit (24), and optionally in conduit (14) as carrier gas for sulfur compounds, Regardless of the reason, it is highly valued when there is a shortage of pure hydrogen. At that time, there is no need to stop the operation of the unit, and it is sufficient to temporarily use the hydrogen in the unit. This is not possible in the prior art, where all operating equipment must be shut down if there is a shortage of pure hydrogen.

In FIG. 1, the regeneration zone (10) and the lower zone (26), which is a regenerated catalyst hydrogen treatment zone, are placed on the side of the first reactor (29), and below the first reactor (29). The arrangement requires a lift (19) as a lifting device in order to lift the regenerated and treated catalyst upward again.

EXAMPLE 2 However, when the reactor is not large, or even in some cases, it may be advantageous to carry out the invention with a separate arrangement as illustrated in FIG. In Figure 2, the regeneration zone is located above the hydrotreating zone and the sulfiding zone, both of which are themselves reaction zones in which the hydrogen treated and sulfided regenerated catalyst is placed. placed higher up. According to this method, one lift can be eliminated, thus reducing the total amount of catalyst used in the device and allowing smoother flow of catalyst from the regeneration zone into the first reactor. Become.

In FIG. 2, three reactors are used.

The charge is introduced into the first reactor (29) through channel (1), furnace (2) and channel (3). First reaction device (2
The effluent from 9) is removed by a conduit (30);
The second reactor (4) passes through the furnace (37) and the conduit (38).
2). The effluent from the second reactor (42) is taken off by conduit (43) and is removed from the furnace (50) and conduit (
51) and sent to the third reactor (55).

The effluent from the third reactor (55) is removed by a conduit (56). Upon start-up of the unit, the unused catalyst is transferred to the first reactor (27) (28) together with the conduit not shown in FIG. 2 or the regenerated catalyst.
29). The catalyst is in the form of a fluidized bed.
Proceed to reactor (29).

The catalyst is removed from the first reactor (29) by a plurality of conduits (31) (32) as well as a conduit (33) which takes the catalyst to the lift pot (34). This withdrawal is done continuously (therefore no gate valve system is required). The catalyst flow rate can be adjusted using the lift pot (3
4) is secured by classical means by pure hydrogen injected by a conduit not shown in the figure or by the force of hydrogen generated within the unit.

The gas flow rate of the unit is adjusted to prevent a portion of the reaction effluent from being carried away with the catalyst particles. The catalyst is then transported from the lift pot (34) to the second reactor (42) by any known lifting and unloading device, herein referred to by the word "lift". The fluid in the lift (36) may be recycled hydrogen, ie hydrogen produced by the unit, introduced through the conduit (35).

The catalyst thus transported into the lift (36) reaches the receiver (39) and from there a plurality of conduits (40) (41
) to reach the second reactor (42). Here, the receiver (39) as well as the conduits (40, 41) may optionally form part of the second reactor (42). In other words, these may be provided within the second reactor (42).

The catalyst passes through a second reactor (42) in the form of a fluidized bed;
As for the first reactor (29), a plurality of conduits (4
4) (45) from the second reactor (42) and reaches the lift pot (41) by a conduit (46). For example, by means of a lift (49) fed with recycled hydrogen or unit hydrogen coming through a conduit (48), the catalyst reaches a receiver (52) from where it is flowed through a plurality of conduits (53) (54). □ of the bed reaches the third reactor (55). The catalyst is supplied to the first and second reactors (2
9) Similar to (42), a plurality of conduits (57) (
58) from the third reactor (55).

This spent catalyst reaches the lift pot (60) by conduit (59). This spent catalyst is then transferred to an [accumulator decanter] flask (7), for example by means of a lift (6) fed with recycled hydrogen which is fed by a conduit (61) into a lift pot (60).
sent to. The spent catalyst reaches the 11 green zone (10) through the gate valve system (8) and conduits (21) (9).

When the regeneration of the catalyst is completed, the regenerated catalyst is transferred to the flow path (11) (1
3) as well as the enclosure (
15) into which hydrogen is pumped through conduit (14). The catalyst is, for example, a conduit (23H
25) by conventional means such as the lower or surrounding area (15).
) towards the lower zone (26).

In the lower zone (26), the regenerated catalyst is hydrotreated with hydrogen introduced through the conduit (14) as a fixed or fluidized bed. This treatment is carried out at the desired temperature, here below 450 DEG C., as described with respect to FIG.

The regenerated and hydrogen-treated catalyst is removed from the enclosure (15) (located above the first reactor (29)) by means of a conduit (4) and optionally a gate valve (16) and transferred to the first reactor (29). 1 Continuously descends into the receiving flask (17) located above the reactor (29). The sulfurization reaction can start from the receiving flask (17), but in some cases the sulfur compounds carried by the hydrogen stream are
It is introduced through conduit (24). The catalyst is then activated by the conduit (18H5) as well as the gate valve (19
) and continue descending into the accumulator flask (20). The catalyst is then connected to a plurality of conduits,
i.e. from the accumulator flask (20) in the form of a fluidized bed through r ml J (27) (28).
It flows continuously up to the reactor (29).

The catalyst is transferred from the outlet of the enclosure (15) to the first reactor (29).
(in some cases the gate valve is open or removed) to ensure correct regulation of the hydrogen treatment and sulfiding temperatures and to ensure that the catalyst is not subjected to sudden temperature fluctuations. flows in the form of

During hydrogen treatment, excess hydrogen is removed from the discharge pipe (22).
can be removed through.

The sulfurization carried out after the hydrotreatment of the regenerated catalyst is carried out in the apparatus according to FIG. 2 partly in the receiving flask (17), partly in the conduits (18) (5), and in some cases even once. Part is accumulator flask (20)
as well as in the legs (27) (28).

1 and 2 illustrate a method characterized in that the regenerated catalyst is first subjected to treatment with hydrogen at a temperature below 450° C. before being reintroduced into the reactor.

Because the hydrogen treatment takes place at relatively low temperatures, temporary unit gas can be used in the event of a shortage of pure or purified hydrogen without fear of hydrocracking side reactions that may cause an explosion in the equipment. On the one hand, this hydrogen treatment can be carried out, and on the other hand, in the case of FIG. 1, the regenerated catalyst can be lifted again towards the first reactor by means of a lift with hydrogen as the propelling fluid.

By the way, (the hydrogen treatment is carried out at a temperature between 320 and 370°C, preferably around 350°C, the sulfidation is carried out at a temperature 70 to 130°C lower than the hydrogen treatment temperature, and this temperature is between 200 and 280°C). (preferably between 220 and 280°C, and preferably close to about 250°C), e.g. As long as the hydrogen in the unit has undergone relatively simple purification such as washing, the hydrogen produced in the unit can be used for hydrogen processing and (
It has now been recognized that it is now possible to use a lift in the apparatus for the carrier gas (for transporting the catalyst treated with hydrogen to the top of the reactor) during the entire operating life of the unit.

The hydrogen within the unit purified in this manner will hereinafter be referred to as "refined unit hydrogen". Due to the relatively low temperatures of the hydrogen treatment and sulfidation reactions,
It originated within the unit and was easily purified without being advanced to a high level.

Such hydrogen, despite the impurities it still contains after this simple purification, is not susceptible to parasitic explosions due to n1 flipping, such as hydrocracking due to hydrocarbons it may contain. It should be. fact,
This side reaction cannot occur at the relatively low temperatures used in hydrotreating and sulfidation.

In the process of Figures 3 and 4, the hydrotreatment of the catalyst and its sulfidation are carried out at relatively high temperatures, generally close to those used in the reactor itself, so that pure hydrogen or It is absolutely not possible to use recycled hydrogen, i.e. hydrogen within the unit, which requires prior rigorous purification by very expensive physicochemical methods, such as passing hydrogen over molecular nodes or purification by low temperature chemical methods. It was necessary. In Figures 1 and 2, recycled hydrogen, ie hydrogen within the unit, could be used temporarily.

1 and 2 according to the invention, the regenerated catalyst is subjected to treatment with hydrogen in the area (15) of these figures or in the form of a fixed bed or in the form of a fluidized bed. Preferably, the enclosure (15) is of the yL moving bed type, in order to ensure better continuity of the catalyst progress.

In this case, in order not to crowd the drawing, it is necessary to change the periodic withdrawal from the regeneration zone (10) into a continuous feed into the hydrotreating zone, for example when regeneration is carried out in a fixed bed. Not shown are any additional gate valves or vessels required to do so.

Similarly, treatment of the regenerated catalyst with hydrogen is in the area (15) in the figure.
When carried out in a fixed bed in a
Also not shown is the ancillary equipment necessary for continuous advancement from the outlet of 15) towards the sulfidation zone.

[Brief explanation of the drawing]

1 and 2 are pipe system diagrams showing an embodiment of the present invention, and FIGS. 3 and 4 are pipe system diagrams showing the prior art. Applicants for the above patents: 2 people other than Institut Les 7 Lances Figure 1

Claims (12)

[Claims] (1) A process for the reforming of hydrocarbons, i.e. for the production of aromatic hydrocarbons, in the temperature range from 480 to 600° C. and in the presence of a catalyst, in which an initial charge consisting of hydrogen monoxide and hydrogen is The flow is conducted through at least two reaction zones arranged in series and each of the fluidized bed type, with the charge flowing through each reaction zone in turn and the catalyst flowing through each of them from above, also in the form of a fluidized bed. A method in which the regenerated catalyst flows continuously to the bottom and passes through each reaction zone in turn, and the catalyst is continuously removed from the bottom of the last reaction zone through which the charge has passed and is sent into the regeneration zone. passing through a hydrotreating zone distinct from the reaction zone, in which the catalyst is intended to undergo partial reduction;
being hydrotreated at a temperature below 450° C.; the regenerated and hydrotreated catalyst is continuously passed down through a first enclosure, the first enclosure having a sulfur compound injected therein; The regenerated and hydrotreated catalyst is
From said first enclosure there is continuous flow into a second enclosure which is located above and distinct from the first reaction zone through which the charge has passed, and the catalyst then passes through said first enclosure. from the second enclosure into the first reaction zone, said regenerated and hydrotreated catalyst flowing continuously from said first enclosure to said first reaction zone, said A process characterized in that it undergoes sulfurization carried out in the temperature range from 200 to 390° C. with the force of a sulfur compound injected into the first zone of the sulfur compound. (2) The hydrogen treatment temperature is in the range of 380 to 445°C, and the sulfidation temperature is in the range of 260 to 390°C and is at least 50°C lower than the temperature at which the hydrogen treatment is performed. the method of. (3) The method according to claim 1, wherein the hydrogen treatment temperature is in the range of 150 to 290°C, and the sulfidation temperature is in the range of 200 to 390°C. (4) The method according to claim 1, wherein the hydrogen used for hydrogen treatment of the regenerated catalyst is hydrogen within the apparatus. (5) an alumina support, and (a) 0.2 to 0.4% by weight of a first metal selected from platinum, iridium, ruthenium, and rhodium relative to the alumina support; (b) a first metal; 0.02 to 0.07% of a second metal different from the metal and selected from iridium and rhodium
and (c) 0.25 to 0.55% of at least one third metal selected from copper, silver, gold, titanium, niobium, indium, thallium, manganese, germanium, tin, lead, and rhenium. , (d) 0.1 to 10% of halogen. (6) an alumina carrier; (a) 0.45 to 0.65% by weight of a first metal selected from platinum, iridium, and rhodium; and (b) a first metal; are different and iridium, rhodium, ruthenium,
(c) a second metal selected from palladium, osmium, and rhenium; and (c) a third metal selected from copper, silver, gold, manganese, titanium, niobium, thallium, cadmium, and indium. , (d) 0.1 to 10% of halogen. The method according to claim 1 for the production of high purity aromatic hydrocarbons in the presence of a catalyst containing 0.1 to 10% of halogen. (7) A first enclosure into which a sulfur compound is injected on the one hand and a hydrogen stream on the other hand which carries the regenerated and hydrotreated catalyst into a second enclosure. A method according to claim 1, which is for aiding in continuous frying. (8) The humidity of the hydrogen treatment is in the range of 380 to 445°C, and the temperature of sulfidation is in the range of 260 to 390°C and is at least 50°C lower than the temperature at which the hydrogen treatment is performed. the method of. (9) The method according to claim 7, wherein the hydrogen treatment temperature is in the range of 150 to 290°C, and the sulfidation temperature is in the range of 200 to 390°C. (10) Transfer the regenerated and hydrotreated catalyst to the second
8. The method of claim 7, wherein the hydrogen that assists in transporting the hydrogen to the surrounding area and the hydrogen that is used to hydrotreat the regenerated catalyst is hydrogen within the apparatus. (11) an alumina support, and (a) 0.2 to 0.4% by weight of a first metal selected from platinum, iridium, ruthenium, and rhodium relative to the alumina support; (b) a first metal; 0.02 to 0.07% of a second metal different from the metal and selected from iridium and rhodium
and (c) 0.25 to 0.55% of at least one third metal selected from copper, silver, gold, titanium, niobium, indium, thallium, manganese, germanium, tin, lead, and rhenium. , (d) 0.1 to 10% of halogen. (12) an alumina carrier; (a) 0.45 to 0.65% by weight of a first metal selected from platinum, iridium, and rhodium; and (b) a first metal; are different and iridium, rhodium, ruthenium,
(c) a second metal selected from palladium, osmium, and rhenium; and (c) a third metal selected from copper, silver, gold, manganese, titanium, niobium, thallium, cadmium, and indium. (d) 0.1 to 10% of halogen. The method according to claim 7 for the production of high purity aromatic hydrocarbons in the presence of a catalyst containing 0.1 to 10% of halogen.