JPH05194962A - Method and equipment for preparing aromatic hydrocarbon in region provided with reactor-heat exchanger - Google Patents

Abstract

PURPOSE: To improve the life of a catalyst and the temp. efficiency of a manufacturing method.

CONSTITUTION: In the production of an aromatic hydrocarbon from 2-12C aliphatic hydrocarbon feedstock in a reaction zone equipped with a pipe 10 packed with a catalyst, one reaction stage is contained and air and fuel are passed through a gas generator 1 during this reaction stage. The gas generator 1 introduces heated gas with a pressure of 2-10 bar and a temp. of 600-1200°C into the calender 11 of a reactor-heat exchanger 9. This gas heats a pipe 10 through which the feedstock flows and is discharged from the calender 11 to be successively sent to an output recovery turbine 18 and a heat recovery chamber 19. The outflow material is recovered and, next, the pipe 10 is purged and the catalyst is subsequently regenerated.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates, in the presence of a crystalline zeolite catalyst compositions, methods for the preparation of aromatic hydrocarbons from C ₂ -C ₁₂ aliphatic hydrocarbon feeds. More specifically, the present invention relates to the synthesis of mixtures containing mostly benzene, toluene and xylene. These are substances that can improve the octane number of gasoline in particular. Finally, the invention relates to a hydrocarbon converter using an endothermic reaction and its use, in particular for the production of aromatic hydrocarbons.

[0002]

2. Description of the Related Art Effective utilization of low boiling point aliphatic distillates such as LPG helps to form hydrogen as a by-product, and at the same time has good performance, selectivity and economical efficiency. Demonstrate the potential benefits of implementing these hydrocarbon conversion processes.

Prior arts include patents WO-A-8,700,546 and US-A-
Illustrated by 4,411,870, US-A-2,185,928 and US-A-2,433,345.

The reaction for the production of aromatic hydrocarbons has been described in particular in US
3,760,024, U.S. Pat.
Alternatively, it is described in the presence of a zeolite catalyst containing off-frame metal as described in patents FR-2,374,283 and US 4,175,057.

The basic processes carried out in the conversion of aliphatic hydrocarbons into aromatic hydrocarbons are mainly the dehydrogenation of paraffins, the oligomerization of the resulting unsaturated hydrocarbons and the cyclization of the oligomers. Overall, the reaction is strongly endothermic, the reaction rate is sensitive to temperature changes, and these continuous reactions result in the deposition of coke on the catalyst and the metal oxides contained in the catalyst. With the reduction of. This deactivates the catalyst very quickly, reducing cycle life.

[0006] Therefore, one of the problems to be solved, knowing that the catalyst is even more sensitive to temperature rise and that the catalyst can be destroyed above the critical temperature,
The aim is to ensure the homogeneity of the heating of the reaction zone at about 500-600 ° C., so that a temperature curve as constant as possible in the reaction zone can be obtained.

Furthermore, it has been noticed that the endothermic heat demand is not constant during the course of the aromatic hydrocarbon production reaction.

Another problem to be solved relates to catalyst regeneration. The regeneration must be rapid and of varying frequency, depending on the reaction temperature, which is directly dependent on the feed to be treated, but generally the regeneration is carried out, for example, every 12 hours. Play this
(regeneration) maintains the performance of the catalyst and the regeneration rate of the catalyst
It must be loose enough to minimize (taux de renouvellement). However, in order to keep the activity of the catalyst as long as possible, it is preferable to reach the combustion temperature of the coke as quickly as possible and to maintain a substantially constant temperature level over the entire length of the tube.

The object of the present invention is to solve the problems raised above so as to improve the life of the catalyst and the temperature efficiency of the process.

[0010]

More particularly, the present invention relates to C ₂ -C ₁₂ in at least one reaction zone comprising a plurality of substantially parallel tubes containing a fixed bed of catalyst composition. The present invention relates to a method for producing an aromatic hydrocarbon from an aliphatic hydrocarbon charging raw material. The process is (a) an aromatic hydrocarbon production reaction step, during which the optionally preheated feedstock is passed through the tube under suitable conditions under conditions of aromatic carbonization. Recovering the hydrogen-rich effluent, (b) purging the tubing with at least one suitable purge gas after the reaction step and after the catalyst regeneration step, wherein the purge effluent is recovered,
And (c) a regeneration step in said tube of coke-deposited fixed bed catalyst at the time of the reaction step with at least one regeneration gas under suitable regeneration conditions, wherein the regeneration effluent is recovered. ..

The process comprises at least one reactor under pressure in the reaction zone with a tube (10) and a calendar (11).
Introducing the feedstock into one of the ends of the heat exchanger (9) and allowing the feedstock to flow inside the reactor-the tubes contained in the heat exchanger, -in the reaction stage: (A1) passing a quantity of air and a quantity of fuel through at least one gas generator (1) suitable for providing heated gas at a suitable pressure and temperature, (a2) preferably charging On the feed side of the raw material (15), the reactor-heat exchanger, the gas is sent to the inlet of the calendar (11), the gas is circulated in the calendar of the reactor-heat exchanger, and the charged raw material, The heating of the tubes through which the feedstock flows is carried out according to the step of indirectly performing heat exchange, preferably in co-current: -said gas via the calender outlet (16) to the other end. Discharge and-at the level of said other end (21) said effluent rich in aromatic hydrocarbons It recovered, characterized in that.

The combination of these various steps lends itself to excellent heat exchange in very economical conditions and in very short times. These conditions favor the overall chemical reaction being carried out.

Furthermore, preferably the heating gas is sent to the inlet of the reactor-heat exchanger calender (introducing side of the feedstock), so that at the start of the sequence of reactions concerned, a higher demand for the heat of reaction is required. Can also be accepted.

According to a characteristic of the process, the pressure of the heating gas entering the reactor-heat exchanger calender is generally from 2 to 10 bar (1 bar = 10 ⁵ Pa), these temperatures being from 600 to
It is 1,200 ℃. Excellent results in terms of energy efficiency were obtained when the pressure of the heating gas was 6-8 bar and these temperatures were 650-1,000 ° C.

According to another characteristic of the method, the ratio of the flow rate of the heating gas to the flow rate of the feedstock flowing in the tube is generally 2-8, preferably 3-5.

Preferably the heating gas and the feedstock flow in the same direction.

In order not to send a heating gas at a flow rate that is too high with respect to the flow rate of the feed, at least part of the reactor-heat exchanger calendar, preferably in the middle of this reactor-heat exchanger, At least a portion of the heating gas, which may contain 15 to 19% by volume of oxygen, provides an appropriate amount of gaseous fuel and, optionally, an inert gas (eg, CO ₂ , steam, nitrogen) in situ. It may be advantageous to carry out the controlled combustion during the reaction stage. The fuel may be injected under conditions such that the temperature remains substantially constant throughout the tube.
For example, French application FR 91- filed by the applicant
Controlled combustion means, such as those described in 04687, may be used for this purpose. For example, they may comprise at least one injection pipe, one of the ends of which is connected to a fuel introduction means and optionally an inert gas introduction means. This injection tube is usually provided with a plurality of orifices in its peripheral portion. The opening surface area of this may be gradually smaller in the flowing direction of the heating gas. The effluent of this combustion is discharged with the heating gas.

The reaction tube is further provided with a control and regulating means which is connected to a temperature sensor arranged above the effluent discharge means and which comprises an automatic controller suitable for regulating at least one fuel flow valve. The temperature of can be maintained according to the desired temperature curve. That is, it is possible to maintain a substantially constant temperature over the entire length of the tube, or a substantially higher temperature at the level of the tube on the side where the raw material is introduced.

Finally, steam may be preferably mixed with the gaseous fuel in order to control its flow rate, avoid hot points at the level of the injection orifices and prevent hydrocarbon decomposition of the fuel.

According to another characteristic of the process, the heated gas is discharged at the outlet of the calender at a pressure of 2 to 8 bar and a temperature of 500 to 1,000 ° C. and these are sent to at least one power recovery turbine. Good. This turbine recovers energy from these gases and, in this way,
For example, at least one compressor can be utilized to separate hydrogen from the vapor phase of the hydrocarbon effluent.
The residual heat energy at the outlet of the power recovery turbine is
It can be used in a heat recovery chamber, for example to generate steam.

According to another characteristic of the method, a temperature of 40
Recover aromatic hydrocarbon-rich effluent at 0-600 ° C,
It can be sent to a heat exchanger. The aliphatic hydrocarbon feed is preheated here, preferably in cocurrent and at a suitable temperature.

According to another feature of the process, the hydrocarbon effluent may be passed through a heat exchanger before being sent to a cooler and then to a separator. This separator provides for the most part a liquid hydrocarbon phase to be recovered and a vapor effluent phase containing hydrogen which is sent to the compressor for later separation.

According to an embodiment of the method, the reaction zone is
It may be equipped with at least two reactor-heat exchangers. In that case, the reaction stage of the production of aromatic hydrocarbons is carried out in the reactor--the tube of the heat exchanger, while the other reactor--
Purging and catalyst regeneration steps are carried out in the tubes of the heat exchanger. Or vice versa. Under such conditions, the calenders of the two reactors are connected to the gas generator.
According to another characteristic of this method of implementation, at the outlet of the gas generator, the flow of heating gas is such that a fraction of at most 10% of the gas is purged and at least part of the regeneration It may be tapped into the heat exchanger and split so that at least 90% of the gas fraction is tapped into the reactor-heat exchanger in which the reaction steps are carried out.

In this way, the initiation of combustion in the tubes of the regenerator is promoted.

According to the characteristics of the reaction stage, the regeneration or purge effluent may be sent to a heat exchanger at a temperature of 400-600 ° C. In this heat exchanger, the regeneration or purge gas is preheated, preferably in cocurrent, at a temperature 10 to 100 ° C. below the temperature at which coke combustion begins.

Upon exiting this, it is, as in the case of hydrocarbon effluents, an energy recovery device, eg at least one.
It may be sent to one heat exchanger or a power recovery turbine.

According to another characteristic of the method:
A purge step is performed between the hydrocarbon production step and the spent catalyst regeneration step. To do this, either stop the feed of the feedstock to the tube, or stop the heating in the calendar, or part of the heating gas,
The tube is purged with an inert gas such as nitrogen at least once under flow and temperature conditions such that it is sent to the calender as described above, or the temperature of the catalyst remains substantially constant. This allows the catalyst to be in an atmosphere of an inert gas and then contacted with oxygen during the regeneration stage or with hydrocarbons during the reaction stage.

According to another characteristic of the process, generally, an optionally preheated inert gas and at least one gas containing 0.05 to 3% by volume of molecular oxygen are injected to regenerate the catalyst. Carry out the steps.

It will be appreciated that alternating actuation by a suitable set of valves, controlled by suitable control and regulation means, is very adaptable. Furthermore, the transition times between the reaction stage and the catalyst regeneration stage are short, since the temperatures are substantially the same in both cases and the whole process is carried out in the same tube.

Generally, the reaction is carried out in an inert atmosphere at a pressure of 0.2 to 10 bar and a temperature of 400 to 600, depending on the kind of the raw materials.
It is carried out at ° C. The temperature is preferably 480 for the LPG fraction.
~ 550 ° C, in the case of the naphtha fraction 450-530 ° C, preferably at a pressure of 1-5 absolute bar. Preferably this temperature is between 500 and 530 ° C for LPG fractions and 48 for naphtha fractions.
It is 0 to 510 ° C.

The catalysts used are generally MFI-type crystalline zeolites such as ZSM zeolites, eg the patent US Pat.
ZSM5, ZSM8, ZSM11 as described in 3,970,544
, ZSM12 and ZSM35.

The zeolite is preferably at least 1
It could include one metal.

For example, zinc, gallium, and preferably gallium can be mentioned. These metals may be within the framework or outside the framework.

Similarly, with or without metal,
Zeolites synthesized in a fluoride medium may be used.

The catalyst is used in fixed bed form. This reduces wear phenomena.

The recommended space velocity is usually 0.5 to 5 h ⁻¹ , preferably 1.5 to 3.0 h ⁻¹ , depending on the feed.

Aliphatic hydrocarbon feeds (fresh and recycled) generally contain from 2 to 12 carbon atoms. This feedstock advantageously comprises LPG or naphtha. Operating conditions may vary depending on the type of feedstock. For example, when using a feedstock such as LPG, the operation may be carried out at a temperature higher than the temperature at which the operation is performed using a feedstock such as naphtha. The device thus makes it possible to accept feeds of various compositions very rapidly and by easy adjustment of the reactor-heat exchanger temperature.

In general, the operating conditions, especially in the case of LPG, convert at least 60%, preferably at least 80%, of the feed so that the proportion of aromatic hydrocarbons is at least 65% of the initial feed. Optimized to be

The regeneration is usually carried out at a temperature of 450 to 650 ° C, preferably 480 to 560 ° C.

A device for carrying out an endothermic reaction, for example of the type of reaction mentioned above, is connected at one end to a feed means (14) for the feed, which is optionally preheated, and at the other end. Was connected to a hydrocarbon effluent recovery means (23),
Multiple reaction tubes filled with at least one fixed bed catalyst
(10) at least one reactor, a means for purifying the spent catalyst comprising a means for purging the tube, a means (36) for supplying the regeneration gas, and a means (39) for discharging the regenerated effluent, The regeneration means connected to the is suitable for regenerating the spent catalyst in the pipe, the device comprises a feed means for the feedstock and a means for recovering the hydrocarbon effluent, followed by the spent catalyst A device comprising alternating switching means, suitable for alternately connecting pipes to the regeneration means, wherein the reactor comprises: (a) a first inlet (3) for air and at a constant temperature and pressure, At least one gas generator with a second inlet (4) for fuel suitable for delivering heated gas through the outlet (8)
(1); (b) at least one reactor under pressure, preferably in the form of a vertical, elongated shape, comprising a tube (10) and a calendar (11)-
A heat exchanger (9), at one of its ends, an inlet for the gas, which is connected to the outlet of the gas generator and is connected to the reactor-calender of the heat exchanger through which the gas flows; And a charging material supply means (14) connected to a plurality of reaction tubes, the tubes are heated by indirect heating by the gas, the calendar is equipped with gas turbulence means, the reactor -A heat exchanger in combination with at the other end an outlet (16) for the gas flowing through the calender and the means (23) for collecting the hydrocarbon effluent. The device is characterized by being provided.

A post-combustion chamber can be added if the temperature of the heated gas is not sufficient for that required for the reaction. It is inserted between the outlet of the gas generator, more particularly the power recovery turbine associated with the compressor, and the inlet of the gas in the reactor-heat exchanger. This chamber may be an integral part of the generator.

The entire device has a very flexible concept. The investment is reduced as long as the entire equipment is already on the market. Furthermore, their combination is
It leads to great thermal efficiency.

According to a feature of this device, the reactor-heat exchanger is generally equipped with a feedstock, optionally preheated in the reaction tube, and a co-current flow of the heating gas in the calender from below to above. Are suitable.

According to the features of the gas generator, this generator comprises a shaft compressor (2) having a transmission shaft (7) connected to a first inlet (3) for air, said compressor and fuel. The second entrance of (5)
A combustion chamber (4) for the combustion of fuel with compressed air, which is connected to
A power recovery turbine (6) connected to the shaft of the compressor and suitable for extruding compressed air and pressurized combustion gases in the reactor-heat exchanger. The turbine further comprises the gas outlet.

The apparatus is generally connected to a hydrocarbon effluent recovery means, and feedstock is fed to the reactor before entering the reactor-heat exchanger, preferably by indirect heat exchange with said effluent in cocurrent. It comprises at least one gas-gas second heat exchanger (24) suitable for preheating.

The heated gas leaving the calendar is generally recovered in at least one second power recovery turbine (18) connected to the heated gas outlet of the reactor-heat exchanger. The turbine is connected to the heat recovery chamber (19).

According to another characteristic of the device, the hydrocarbon effluent is cooled in a cooler connected to the second heat exchanger (24). This cooler is connected to the separator (27). The separator provides a vapor phase and a liquid phase that are compressed by a compressor (30) connected to the second power turbine.

According to a preferred feature of the device, the device comprises a first reactor-heat exchanger (9) comprising a plurality of tubes (10),
A second reactor comprising a plurality of tubes-a heat exchanger (33). This second reactor-heat exchanger is adapted to purge and regenerate the catalyst while the first reactor-heat exchanger is adapted to carry out the heating reaction stage. The first reactor-heat exchanger calendar (11) is connected to the outlet of the gas generator and the second reactor-heat exchanger calendar is
(34) is connected to the outlet of the gas generator. The regeneration tube has a purge and regeneration gas supply means (36) at one end.
And the other end is connected to purge and regeneration effluent discharge means (39). The device also
Alternate switching means suitable for alternately connecting the reaction tubes to the charging material supply means and the effluent recovery means, and then to the purge and regeneration gas supply means and the purge and regeneration effluent discharge means. Provided, these alternate switching means,
Further, it is possible to connect the regeneration pipe alternately to the purge and then the regeneration gas supply means, the purge and then the regeneration effluent discharge means, and then to the charging material supply means and the hydrocarbon effluent recovery means (8). Suitable, the reaction tube operates in the so-called reaction stage, while the regeneration tube operates first in the so-called purge and regeneration phase, then the reaction tube becomes the regeneration tube, while the regeneration tube then Being a reaction tube, the switching means connects the calender of the first reactor-heat exchanger to the gas generator by means of a suitable valve (44) during the reaction stage, at least for a certain time during the regeneration stage, A suitable valve (48) is suitable for disconnecting the second reactor-heat exchanger calender from the gas generator.

The reactor-heat exchanger is conventional and
It is known to those skilled in the art.

The present invention is better understood by looking at the drawings. This drawing schematically shows an embodiment of an apparatus applicable to the production of aromatic hydrocarbons, which combines mechanical energy recovery with a power recovery turbine downstream of the apparatus.

The gas generator (1) may be part of a reaction motor or a gas turbine (Hispano Suiza THM 1103), which is the axial compressor (2) of the air provided by the line (3). ), Which compresses air and heats it at about 400 ° C. This compressed air passes through the combustion chamber (4). This is the part that makes up the entire reaction motor, which is supplied with fuel from line (5). This fuel may range from methane to fuel oil (fioule). Exothermic combustion is initiated and carried out at a constant pressure, raising the temperature of the air to approximately 75
Raise to 0 to 850 ℃. Air and combustible materials, referred to herein as heated gases, are then decompressed in a high pressure power recovery turbine (6). This activates the air compressor (2) by means of the transmission shaft (7). The heated gas at 750-850 ° C and a pressure of about 6-8 bar (1 bar = 10 ^-5 Pa) passes through the line (8) and at the outlet of the turbine (6) under pressure (eg 20 bar). It is extruded towards a first reactor-heat exchanger (9) with a tube (10) and a calender (11), preferably of a vertically elongated shape, suitable for operation. The heating gas is in fact sent via the line (8a) towards the lower end of the reactor-heat exchanger calendar (11). The calender itself is welded to the perimeter of the calender with an inner wall suitable for creating a baffle flow of heated gas and promoting turbulence, for example a central non-hollow disc It has an inner wall containing alternating hollow disks (G.
A. Skrotzki, Power, June 1954, in this paper, "dis
It uses the English term "c and doughnut").

The calendar is hermetically sealed by two transverse walls (12) (13). The upper and lower ends of these are welded to the closed vessel of the reactor, and a plurality (for example, 50-
500) supporting the reaction tube (11). These tubes are preferably provided with fins arranged advantageously along the axis of the tubes in order to improve the heat transfer efficiency, these tubes are preferably substantially parallel to one another and the reactor-heat Substantially parallel to the axis of the exchanger. These are the airtight chambers at the bottom
You are familiar with (15). In this room, the arrival pipe of the raw material (14)
Via preheated, for example naphtha, at 450 ° C. and a pressure of 4.5 bar. The feedstock flows inside the tube from bottom to top. These tubes are filled with a fixed bed of catalyst. This is generally MFI type crystalline zeolite,
For example, ZSM5, which advantageously contains gallium. This feedstock flows in cocurrent with the heating gas. These gases pass through the calendar from bottom to top. These gases are collected at the upper level outlet of the calender, at about 600 ° C at 5-7 bar via line (16) and storage tank (17) (ballon de garde).
To the second power recovery turbine (18).
Upon exiting the turbine, the gas at a temperature of about 400 ° C. and a pressure of 1.1 bar is sent to a heat recovery chamber (19) where steam may be emitted and then to a chimney (20).

The reaction tube (10) is brought to a temperature of about 600 ° C. and is the site of an endothermic reaction which results in the production of aromatic hydrocarbon and hydrogen-rich effluent.

The effluent and unconverted raw material are recovered in the airtight recovery chamber (21) at the upper end of the reactor-heat exchanger.
The collection chamber is separated from the calendar by the upper transverse wall that supports the tubes.

This chamber is connected via an expansion joint (22) to
It is connected to the effluent recovery line (23). This effluent is sent at a temperature of about 450 DEG-550 DEG C., at 2-3 bar, via said line to a second heat exchanger (24) with vertical elongated tubes and a calender. It is suitable for indirect heat exchange with the feedstock before entering the reactor-heat exchanger. The preheated feed introduced through line (14a) at the top of the calendar and the effluent through the lines flow in cocurrent from top to bottom. The hydrocarbon effluent and unconverted feedstock are discharged via the line (25) at the lower end of the second heat exchanger, introduced into the cooler (26) and then towards the phase separator (27). be introduced. The liquid phase is recovered in the lower part of the separator by a line (28), while the vapor phase of the effluent containing light aromatic hydrocarbons and hydrogen is connected to the upper part of the line (29).
And is compressed by a compressor (30) which is driven by a power recovery turbine (18). These pressurized gas effluents recovered by one line may then be separated and recovered.

The electricity generator (32) may be operated by excess energy recovered at the output of the power turbine.

While this first reactor-heat exchanger (9) is operating in the reaction stage, in all respects it is similar to the first reactor-heat exchanger in the second reactor-heat exchanger ( 33) operates in purge and recovery stages according to substantially the same temperature and pressure conditions.

This Second Reactor-Heat Exchanger Calendar (34)
Is connected to the outlet of the gas generator by its lower inlet and line (8b). After traversing the calender at certain times of the process, these gases are discharged from the upper outlet under the same conditions as previously described, via line (35) and into storage tank (17). It is then directed to the same power recovery turbine (18) generally as described above. The purge or regeneration gas circulated by the compressor (43) is introduced to the top of the calender of the heat exchanger (37) via the line (36). These are preheated in a calender and then introduced at the lower end of the reactor-heat exchanger through a line leaving the lower outlet of the calender calendar. The purge or regeneration gas flows through the reactor-heat exchanger line (38) and the purge or regeneration effluent passes through the discharge pipe (39) at the top of the reactor-heat exchanger,
It is recovered at a temperature of 400-600 ° C and then led to the upper end of the heat exchanger (37). In this heat exchanger, heat is indirectly exchanged with the purge or regeneration gas entering here in a cocurrent flow, and then it exits via the lower end portion and then passes through the pipe (41) to the cooler (4
0) and then to a separator (42) where water is withdrawn and the remaining effluent is burned.

According to the previously described embodiment, the first reactor-heat exchanger (9) is in the reaction stage, while the second reactor-heat exchanger (33) is purging and regenerating the catalyst. In stages.

After the time required for hydrocarbon production (about 12 hours), switching is possible by means of suitable alternating means. The first reactor-heat exchanger is transformed into the regeneration stage, while the second reactor-heat exchanger is transformed into the reaction stage. More precisely, the alternate switching means is such that the reaction tube of the first reactor-heat exchanger is connected to the charging material supply means and the hydrocarbon effluent recovery means, and then to the purge and regeneration gas supply means and the purge and regeneration gas supply means. It is suitable for interlocking with the means for discharging the regenerated effluent.

Similarly, these alternate switching means further include a purge and regeneration gas supply means, a purge and regeneration effluent discharge means, a charging material supply means, and a hydrocarbon effluent recovery means. Suitable for connecting the second reactor-regeneration tube of the heat exchanger.

These alternate switching means are
Control the entire valve (eg valves (44) (45) (46) drawn in white)
(47) is open, black valves (46a) (47a) (50a) (51a) are closed, valves (50) (51) are also open, and reactor-heat exchanger (9) Work in the reaction stage, while the reactor-heat exchanger (33)
The valves (48) (49) are also only partially opened for a certain period of time during the alternating states, which are during the regeneration phase or vice versa).

Furthermore, said alternation means may be arranged such that, during the reaction stage, by means of a suitable valve (44) the first reactor-heat exchanger.
The calender of (9) is suitable for connecting to the gas generator and disconnecting the calender of the second reactor-heat exchanger from the gas generator for at least a certain time during the regeneration phase.

Furthermore, these alternation means are adapted to reduce the flow rate in the reactor-heat exchanger (regenerator) for at least a certain period of time, and in the other reactor-heat exchanger during said period of time. Gradual flow rate, or may be 0-100% 2
It may be suitable for splitting the flow rate of the heating gas so as to provide a substantially constant flow rate in each of the two.

Finally, the control and regulation means are suitable for controlling the temperature level of the device, both in the reaction phase and in the regeneration or purging phase. These include, for example, temperature sensors. Each of these sensors is arranged in the heating gas recovery means of the reactor-heat exchanger. These sensors are connected to automatic controllers (44) (45), which are each suitable for adjusting the flow valve of the heating gas feeding the reactor-heat exchanger. There is.

All these means are connected in a conventional manner to the alternation means described above.

[0067]

The following examples illustrate the method and apparatus according to the invention, and in particular the amount of energy used.

For the treatment of the light naphtha feedstock to aromatic hydrocarbons in the presence of the zeolite catalyst, the following operating conditions are selected, for example:

Addition amount of naphtha 25 tons / hour Preheating temperature 450 ℃ Pressure after preheating 4.5 bar Space velocity 3 h ^-1 Amount of air in gas generator 98 T / h Hispano Suiza THM 1103 Injected fuel 1.6 T / h Gas entering the generator turbine 1,000 ° C, 1.6 bar temperature and pressure Reactor-Entering the heat exchanger calendar 800 ° C, 7 bar Heating gas temperature and pressure Heating gas flow rate relative to naphtha flow rate 4 Reactor-heat Number of exchanger tubes and calendar tubes 330 Inner diameter 100 mm Length 6,000 mm Reactor-heat exchanger transfer surface 520 m ² Reaction temperature 450-500 ° C Hydrocarbon effluent temperature and pressure 500 ° C, 2.5 bar Aromatic carbonization Hydrogen-separated vapor phase 13 T / h Aromatic hydrocarbon-separated liquid phase 12 T / h Amount of heating gas leaving the calender 100 T / h, 600 ° C, 6 bar Output recovery turbine 4.7 MW heat recovery chamber (400 ° C, 1.1 bar, 100 T / h gas) reaction stage For floors, the energy balance is as follows (in GJ / h). Combustion in gas generator 83.7 Energy demand for this reaction 25.1 Heat recovery in this room 23.5 Power recovery turbine (4.7 MW) 16.3 Total 64.9 Efficiency 77.5%.

[0070]

According to the method and apparatus for producing aromatic hydrocarbons of the present invention, the life of the catalyst and the temperature efficiency of the production method can be improved.

[Brief description of drawings]

FIG. 1 is a flow sheet showing the method and apparatus of the present invention.

[Explanation of symbols]

 (1) ... Gas generator (2) ... Shaft compressor (3) ... Air inlet (4) ... Combustion chamber (5) ... Fuel inlet (6) ... Output recovery turbine (7) ... Transmission shaft (8) ... Heating Gas outlet (9) (33)… Reactor-Heat exchanger (10) (38)… Pipe (11) (34)… Calendar (14)… Charge feed means (16)… Calendar outlet (18)… Output Recovery turbine (19) ... Heat recovery chamber (23) ... Hydrocarbon effluent recovery means (24) (37) ... Heat exchanger (26) ... Cooler (27) ... Separator (30) ... Compressor (36) Regeneration gas supply means (39) Regeneration effluent discharge means (40) Energy recovery device (44) (48) Valve (56) Automatic controller

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Larry Manck France Orgeval Ryu de Picnar 207 (72) Inventor Laurent You France Monte Saint La Bordeaux du Cormeille 58

Claims (25)

[Claims] 1. An aromatic hydrocarbon from a C ₂ -C ₁₂ aliphatic hydrocarbon feed in at least one reaction zone comprising a plurality of substantially parallel tubes containing a fixed bed of catalyst composition. Wherein the method comprises: (a) an aromatic hydrocarbon production reaction step, wherein during this step, the feedstock optionally preheated in the tube under suitable conditions. Purging the effluent rich in aromatic hydrocarbons, and (b) purging the tube with at least one suitable purge gas after the reaction step and after the catalyst regeneration step described below, Recovering the product, and (c) a regeneration stage in said tube of fixed bed catalyst with coke deposited at the time of the reaction stage with at least one regeneration gas under suitable regeneration conditions, Collect Comprising at least one reactor under pressure in the reaction zone-one of the ends of the heat exchanger (9) -with a tube (10) and a calendar (11). Is introduced into the reactor, and the feedstock is circulated inside the tube contained in the heat exchanger, and during the reaction stage, the following steps are provided: (a1) to provide heated gas at a suitable pressure and temperature. For passing a fixed amount of air and a fixed amount of fuel in at least one gas generator (1) suitable for (a2), preferably on the introduction side (15) of the feedstock, reactor-heat exchanger The step of sending the gas to the inlet of the calendar (11), and circulating the gas in the calendar of the reactor-heat exchanger to indirectly exchange heat with the feedstock, preferably in cocurrent. Perform heating of the tube through which the feedstock flows, according to: -The gas is passed through the calender outlet (16). To the other end and, at the level of the other end (21), recovering the effluent rich in aromatic hydrocarbons. 2. Process according to claim 1, characterized in that the pressure of the heating gases is 2 to 10 bar and their temperature is 600 to 1200 ° C. 3. The pressure of the heating gas is 6-8 bar,
Process according to claim 1 or 2, characterized in that their temperature is between 650 and 1,000 ° C. 4. The pressure of the gas is 2 at the outlet of the calendar.
Discharge at ~ 8 bar, temperature 500-1,000 ° C, and at least one of these puissance recovery turbines (18)
The method according to one of claims 1 to 3, wherein the heat is sent to a heat recovery chamber (19). 5. An aromatic hydrocarbon-rich effluent at a temperature of 400-600 ° C. is recovered and sent to a second heat exchanger (24), preferably in cocurrent, with an aliphatic hydrocarbon. Method according to one of the preceding claims, wherein the feedstock is preheated. 6. The hydrocarbon effluent is sent to a cooler (26) and then to a separator (27), which separator has a hydrocarbon liquid phase to be recovered and the second power recovery turbine (18). A process according to one of claims 1 to 5, which results in a vapor phase containing hydrogen, which is sent to a compressor (30) operated by. 7. A process in which the reaction zone comprises at least two reactor-heat exchangers (9) (33), the purge and catalyst recovery in the pipe (38) of another reactor-heat exchanger (33). While carrying out the steps, the tubes (1) of the reactor-heat exchanger (9)
Process according to one of the claims 1 to 6, characterized in that the reaction step is carried out in 0) or vice versa. 8. A fraction of at most 10% of the gas,
At least a 90% fraction of the gas is ramped up to the reactor-heat exchanger in which the reaction stage is carried out, so that at least part of the purge stage and regeneration is progressively sent to the reactor-heat exchanger. 8. The method according to claim 7, wherein the heated gas stream is split at the outlet of the gas generator so that it is delivered directly. 9. The regenerated or purged effluent is a heat exchanger (3
Sent to 7) at a temperature of 400-600 ℃, in this heat exchanger,
Process according to one of the preceding claims, wherein the regeneration or purge gas is preheated, preferably in cocurrent, to a temperature which is 10-100 ° C below the temperature at which the combustion of the coke is initiated. 10. The recycled effluent is an energy recovery device (4
Method according to one of claims 1 to 9, which is sent to 0). 11. The method according to claim 1, wherein the regeneration gas comprises 0.05 to 3% by volume of molecular oxygen. 12. A process according to claim 1, wherein the ratio of the flow rate of the heating gas to the flow rate of the feedstock is 2-8, preferably 3-5. 13. At least a portion of the heating gas containing 15-19% oxygen in at least a portion of the calender during the reaction step, with an appropriate amount of gaseous fuel and optionally an inert gas, Method according to one of the claims 1 to 12, wherein a controlled combustion in situ is carried out. 14. One end is connected to a feed means (14) for the feed, which is optionally preheated, and the other end is connected to a hydrocarbon effluent recovery means (23). A plurality of reaction tubes filled with at least one fixed bed catalyst (1
Carbonization, comprising at least one reactor comprising (0), means for purifying the spent catalyst, means for purging the tube, means (36) for supplying regenerated gas, and means (39) for discharging regenerated effluent. A hydrogen conversion device, wherein the regeneration means connected to the pipe is suitable for regenerating the spent catalyst in the pipe, and the device is a feed material supply means and a hydrocarbon effluent recovery. Means and then to the means for regenerating the spent catalyst,
In a device with alternating means, suitable for connecting pipes alternately, the reactor comprises: (a) a first inlet (3) for air and an outlet (8) for heated gas at constant temperature and pressure. At least one gas generator with a second inlet (4) for fuel suitable for delivery through
(1); (b) at least one reactor under pressure, preferably in the form of a vertical, elongated shape, comprising a tube (10) and a calendar (11)-
A heat exchanger (9), at one of its ends, an inlet for the gas, which is connected to the outlet of the gas generator and is connected to the reactor-heat exchanger calendar through which the gas flows, And a means for supplying the charged raw material connected to a plurality of reaction tubes (14), the calendar is equipped with a turbulent flow means of gas flowing therethrough, which is suitable for heating the tubes by indirect heating. The reactor-heat exchanger is provided at the other end with an outlet (16) for the gas flowing through the calender and means for collecting hydrocarbon effluent (23); An apparatus comprising a combination of 15. The reactor-heat exchanger is suitable for co-current flow from bottom to top of the optionally preheated feed in the reaction tube and the heating gas in the calender. Equipment by. 16. A shaft compressor (2) having a transmission shaft (7), a gas generator connected to a first inlet (3) for air, and a second inlet (5) for the compressor and fuel. A combustion chamber (4) for the combustion of fuel with compressed air, which is connected to and to the compressed air and the reactor-heat exchanger in which the compressed combustion gas in the reactor is extruded (refouler). A suitable power recovery turbine (6), said turbine further comprising a turbine (6) comprising said outlet for gas,
Device according to claim 14 or 15. 17. A post-combustion chamber comprising fuel supply means is located between the gas outlet of the power recovery turbine and the gas inlet of the reactor-heat exchanger.
A device according to one of: 18. A hydrocarbon effluent suitable for preheating feedstock prior to entry into the reactor-heat exchanger, preferably by indirect heat exchange with said effluent in cocurrent. At least one second gas connected to the recovery means
A gas heat exchanger (24) is provided, It is characterized by the above-mentioned.
A device according to one of the claims 4-17. 19. A reactor-heat exchanger comprising at least one second power turbine (18) connected to the heated gas outlet, said turbine being connected to a heat recovery chamber (19). Device according to one of claims 14 to 18, characterized in that 20. A cooler connected to a second heat exchanger (24)
(26), which cooler is connected to a separator (27), which provides a vapor phase and a liquid phase which are compressed by a compressor (30) connected to the second power turbine. Device according to one of claims 14 to 19, characterized. 21. A first reactor-heat exchanger (9) comprising a plurality of tubes (10), and while the first reactor-heat exchanger is adapted to carry out a heating reaction stage. , A second reactor comprising a plurality of tubes suitable for purging and catalyst regeneration-a heat exchanger (33), the first reactor-heat exchanger calendar (11) being the outlet of the gas generator. Connected to the second reactor-
A heat exchanger calendar (34) connects to the outlet of the gas generator, the regeneration tube has one end connected to the purge and regeneration gas supply means (36) and the other end connected to the purge and regeneration gas supply means (36). An apparatus characterized in that it is connected to a discharge means (39) for the regenerated gas effluent, which further comprises a feed material supply means and an effluent recovery means, followed by purging and regeneration gas. And a purge and regeneration effluent discharge means are provided with alternation switching means suitable for alternately connecting the reaction tubes, which alternation means further comprises purging and regeneration. It is suitable for alternately connecting the regeneration pipes to the gas supply means, the purge and then the regeneration effluent discharge means, and then the charging material supply means and the hydrocarbon effluent recovery means (8). As for the tube, the regenerated tube is the so-called It operates in the so-called reaction phase while it is operating in the di- and regeneration phases,
The reaction tube then becomes the regeneration tube the next time the regeneration tube becomes the reaction tube, and the alternation means is provided by means of a suitable valve (44) during the reaction phase to allow the first reactor-heat exchanger calender to Connected to a gas generator and a suitable valve for at least a certain time during the regeneration phase.
Device according to one of claims 14 to 20, which is suitable for disconnecting the calender of the second reactor-heat exchanger from the gas generator by (48). 22. Each reactor-heat exchanger (9) comprises control and regulation means comprising at least one temperature sensor, said sensor being arranged on the means for collecting heated gas,
22. A reactor-heat exchanger according to claim 14 to 21, characterized in that it is connected to an automatic controller (56) suitable for controlling at least a heating gas flow valve (44) feeding the heat exchanger. Device by one of the. 23. The alternating means comprises, in each of the two reactor-heat exchangers, the flow rate of the heating gas in appropriate proportions, one gradually increasing and the other gradually decreasing. 22. Device according to claim 21, characterized in that it is alternatively suitable for splitting so that the flow ratio is substantially constant. 24. A purge and regeneration effluent discharge means (39) suitable for preheating the purge and regeneration gas by indirect heat exchange with the effluent prior to entering the reactor-heat exchanger. At least one gas-gas heat exchanger (37) connected to the heat exchanger, a cooler connected to the heat exchanger, and a phase separator connected to the heat exchanger. Apparatus according to one of paragraphs 14-23. 25. Inside said reactor-heat exchanger, said combustion means comprises at least one injection pipe, one end of which is connected to a fuel introduction means and optionally an inert gas introduction means. The injection tube is provided with at least one orifice, preferably a plurality of orifices (16), in the periphery thereof, the orifice having an opening surface area gradually decreasing in a direction in which the heating gas flows. A device according to one of the claims 14-24.