JPH0248018A - Burning and desulfurization method and device in circulating bed for gas outflow including incomplete combustion gas, so2, so3 and/or h2s - Google Patents

Abstract

PURPOSE: To efficiently desulfurize waste gases consisting of incomplete combustion gases and SOx or the like by bringing these waste gases into contact with a solid absorbent in the presence of an oxygen-contg. gas. CONSTITUTION: The incomplete combustion gases generated from regeneration of cracking catalyst particles contg. coke are sent to a desulfurization reactor 14 where the gases are brought into contact with the absorbent particles and sulfur is removed. The gaseous oxygen is supplied by an oxygen-contg. gas supplying means 15 to the desulfurization reactor 14. A separating means 17 for the absorbent particles absorbing the sulfur exists at the end of the reactor 14. The separated absorbent particles are partly recirculated to the reactor 14 by conduits 20, 23. The absorbent of the decreased component is supplied from an absorbent particle supplying means 16.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a process and circulation for the incineration and desulfurization of gaseous effluents containing large amounts of sulfur compounds, such as anhydrous sulfite, sulfuric anhydride, hydrogen sulfide and/or mercaptans. Concerning equipment on the floor.

More particularly, the invention applies to the desulfurization of gaseous effluents produced during regeneration of coke or deposited catalyst during catalytic cracking operations of hydrocarbon feeds.

[Prior art and its problems] For example, catalyst regeneration soot contains carbon oxides, especially carbon monoxide, which is dangerous to the environment, incompletely burned hydrocarbons and various forms of sulfur (S02, SO3, H2S). It is well known that in order to limit the risk of contamination,
Many publications have been published.

Thus, U.S. Patent U.S. 4,240,899
describes the introduction of a regenerable absorption material into a catalytic cracking unit, which fixes the anhydrous sulfite released during the combustion of the coke deposited on the cracking catalyst. These absorbent materials flow together with the catalyst as a fluidized bed through a regenerator and a reactor (riser) and are decomposed within the reactor, releasing hydrogen sulfide. Almost all of the sulfur introduced with the feed is sent to the fractionation column and then to the Claus-type device. This desulfurization method does not require a large amount of excessive investment, so it is advantageous from a cost standpoint;
However, it also presents some disadvantages. Absorbent materials generally have a high specific surface area. This can induce a cracking reaction that is hardly selective. Furthermore, since the amount of absorbent required has to be large, this fact leads to a dilution of the catalyst, which causes a reduction in conversion. Furthermore, the regenerated vine material has optimal performance when sulfur fixation is done at a temperature lower than the temperature at which sulfur is released.

Indeed, it is easy to believe that destruction of sulfate requires a higher temperature than the temperature at which it is formed. In a crabking plant, however, the situation is reversed, since the sulfate is formed in the regenerator, ie at a high temperature, and it has to be decomposed at a lower temperature in the cracking reactor or stripping plant. Ultimately, the operating conditions of the riser are adjusted to maximize the production of sought-after, high-value vine hydrocarbons, and not by desulfurization performance. The desulfurization rates achieved below are not as promising.

Another method for desulfurizing sulfur-rich effluents consists in carrying out soot treatment by a wet process after the soot has passed through a heat exchanger.

This soot cleaning requires large-scale equipment that requires a large investment.

The technical problem that has to be solved is therefore any regeneration of cracking catalysts (FCC) consisting of at least one partial regeneration step resulting in the formation of gaseous incomplete combustion products (-carbon oxides, hydrogen, light hydrocarbons). Concerning the incineration and desulfurization of gaseous effluents from equipment.

According to European Patent BP-A-0,137,599, hot effluent acid gas (SoS) is extracted in a fluidized bed, in a tubular reaction column, in the presence of a fine-grained absorbent.

2ゝ 3, H2S).

The effluent flows with the absorbent in a swirling motion in the lower part of the reaction column at a speed that is sharply reduced compared to the velocity at the entrance of the column. This patent therefore only concerns the removal of acid gases.

Additionally, European patent EP-A-0,254,402 and US patent US-A-4,448,674 represent the prior art.

[Means for solving the problems] One of the aims of the method according to the invention is to eliminate the above-mentioned disadvantages and to solve the problems posed.

In fact, a method has been discovered in which the operation is carried out in a dry manner as a circulating bed in a different closed vessel, unique to the desulfurization reaction, especially in the presence of absorbents. This makes it possible to obtain excellent desulfurization results of gaseous effluents containing sulfur compounds in a simple and very cost-effective manner.

More precisely, the present invention aims to reduce the carbon monoxide and incompletely combusted gas (hydrogen, hydrocarbon) content and the sulfur of the gaseous effluent containing large amounts of oxidized sulfur, e.g. This invention relates to a method for reducing content by incineration and desulfurization. This method consists of the following steps: (a) introducing absorbent particles with a particle size of 5 to 5000 micrometers and a specific surface area of 0.1 to 500 m2/g into the first end of a tubular reaction zone; (b) reaction The surface velocity of the gas effluent inside the vessel is 5 to 40 m/
to the end of the reaction zone at a temperature of about 6 seconds.
(c) reducing the sulfur content of the gaseous effluent and combining the sulfur-rich solid particles with the sulfur-poor gaseous effluent at a temperature between 00°C and 1000°C; (d) contacting said gaseous effluent with said solid particles in a flowing fluidized bed of a reaction zone in the presence of an oxygen-containing gas under reaction conditions such that a mixture is obtained; (d) opposite ends of the reaction zone; (e) at least partially separating said sulfur-enriched solid particles from said sulfur-poor gaseous effluent in a separation zone located at (f) recycling at least a portion of said sulfur-enriched solid particles towards said first end of the reaction zone.

The absorbent particles generally contain at least one metal carbonate or metal oxide, which metal may be selected from alkali metals, alkaline earth metals and mixtures thereof. These are advantageously generally 20 to 100% by weight, preferably 50% by weight.
Contains ~95% by weight calcium carbonate. This is particularly advantageous in view of the good stability of the calcium formed and the low supply costs. In fact, calcium carbonate is found, for example, in limestone and dolomite (mixed carbonates of Ca and Mg).

Inactive calcium carbonate is decomposed to produce active calcium oxide, CaO. This in turn reacts with sulfite anhydride in the presence of oxygen to yield calcium sulfate.

This reaction is generally carried out at about 650°C to 1000°C, preferably 750 to 900°C. This makes it possible to carry out the decarbonation sufficiently rapidly and at the same time to develop the large particle size necessary for the sulfation reaction.

The absorbent particles advantageously have a particle size of 5 to 5000 micrometers and a specific surface area of 0.1 to 500 rn2/g.

This particle size allows these particles to be homogeneously fluidized in the reaction zone via the sulfur-containing gas effluent, which is moved in the desulfurization reactor at a surface flow velocity of 5 to 40 m/s, preferably 7 to 20 m/s. It's coming.

According to another feature of the invention, a carrier material impregnated with an absorbent may be used. This support material can be, for example, an equilibrium catalyst released by catalyst replacement in a cracking device. By this, 50~400m2
A large porosity of /g is obtained, and the absorbent allows S
The presence of platinum can be utilized to facilitate O2 fixation. Impregnation of the carrier with the absorbent in the form of a suspension or solution may be carried out using a suitable syringe that atomizes the solution or suspension onto the carrier material particles before introducing the particles into the desulphurization device. good.

According to another feature of the method according to the invention, sulfur (sulphate)
At least a portion of the enriched absorbent particles may be withdrawn directly in the reaction zone or in at least one intermediate zone between the separation zone and the reaction zone, typically at a feed location in the reaction zone, as fresh of absorbent, such as calcium carbonate particles, is reintroduced. Withdrawal may also be carried out at another point in the apparatus, for example within the reactor.

The gaseous effluent may result from the partial regeneration of catalyst particles for the cracking of sulfur-containing hydrocarbon feedstocks in the presence of an oxygen-containing gas.

These particles are charged with coke and sulfur compounds and are regenerated under regeneration conditions in a regeneration zone.

Once the catalyst particles have been at least partially regenerated, they are recycled to the heavy hydrocarbon feed cracking zone.

The regeneration gas effluent containing compounds such as C01HCHCH8O 2'4'26'2, H2S5SO3, once at least partially dedusted, cannot be disposed of into the atmosphere, but rather in the presence of large amounts of auxiliary fuel. Instead of being incinerated in a generally large furnace, it is sent to a device implementing the method of the invention. Their temperature is generally about 500-10
00°C, preferably 600-750°C, and their speed is usually 5-40 m/sec, preferably 7-20 m/sec. In other situations, the regeneration effluent may contain oxygen, provided that it is introduced in excess for complete regeneration of the catalyst.

Generally, the amount of oxygen introduced into the incineration and desulfurization tower is such that the oxygen content in the decontaminated effluent leaving the unit is between 1 and 10% by volume.

Preferably this content is between 2 and 4% by volume. Under these conditions - carbon oxides and incompletely combusted gaseous hydrocarbons
completely oxidized.

According to a feature of the invention, when treating the gaseous effluent from a single regenerator, a quantity of oxygen-containing gas is injected into the column such that the content at the outlet is as specified above.

According to another feature of the invention, when treating several effluents originating from different regenerators, the effluent of the regenerator operated in complete regeneration is provided with the effluent required for the incineration of the gaseous incompletely combusted material. At least a portion of the oxygen can be provided. The remaining portion is then provided by the injection of air or oxygen-containing gas substantially at the same place as the introduction of the effluent to be incinerated into the column.

As mentioned above, the method is also suitable for cracking devices operated in multi-level regeneration.

Under these conditions, the effluents from different floors are brought from different lines and injected into the bottom of the desulfurization reactor, in order to avoid any combustion phenomenon between the reducing and oxidizing phases in the lines. be done. If necessary, supplemental air or oxygen may be supplied so that the oxidation and desulfurization reactions of the gaseous incompletely combusted product are carried out simultaneously.

According to another feature of the invention, non-completely sulphated absorbent particles may be recycled to the desulfurization reactor. These are those which, due to their small size, leave the desulfurization cycle too quickly and are therefore not easily captured by the cyclones or gas-solid separators placed at the end of the tubular reaction zone. . These fine substances are removed through sleeve filters.
a manches), which may be captured by an electrostatic filter or any other means placed after the recovery boiler, but is advantageously recycled to the reactor.

Since the desulfurization is carried out in a closed vessel separate from the cracking device, the operating parameters can be optimally adjusted to obtain the best desulfurization yield. Due to the circulating bed, the process according to the invention allows very good contact between the absorbent particles and the gas to be desulphurized and incinerated. It is likewise possible to operate at a constant temperature for the time required for desulfurization. This facilitates obtaining a high desulfurization yield. Indeed, under said conditions, at least 70%, such as 70-99%, advantageously 80-95%
A desulfurization yield of .

Furthermore, the high surface flow velocity of the gas allows very large gas volumes to be processed in a relatively small size device.

Moreover, the process of the invention ensures simultaneous combustion of any incompletely combusted material and desulfurization of the regeneration effluent by means of a circulating bed of absorbent to a content lower than that which satisfies environmental and health standards. This method is carried out at lower temperatures and is advantageous over the method of incinerating effluents in incinerators, which are generally large in size and therefore expensive, and which operate at high temperatures with the additional energy supply provided by the auxiliary fuel. It is a replacement.

According to the invention, the combustion of the effluents and their desulfurization is facilitated by relatively long residence times in the reaction zone, generally from 0.5 to 4 seconds, preferably from 1 to 2 seconds. This residence time allows for fairly low temperatures, e.g.
Oxidation can be carried out at a level of 1000°C, preferably 750-900°C.

According to a preferred embodiment of the process of the invention, cracking of the sulfur-containing hydrocarbon feed is carried out in a cracking zone and under cracking conditions in the presence of a cracking catalyst.

After the catalyst is separated from the cracking effluent, it is sent to the first regeneration zone. where the catalyst under first regeneration conditions is
Partially regenerated in the presence of oxygen-containing gas. The first regeneration effluent contains, for example, up to 10% by volume of carbon monoxide (Co) and up to 1% of a mixture of hydrogen and hydrocarbons, and up to 1000 p, p, m of sulfur, mostly in the form of SO2 and H2S. Contains compounds. These are generally 6o after dust removal.

It is recovered at a temperature of ~750°C and fed to the desulfurization reaction zone. The partially regenerated catalyst is then sent to a second regeneration zone where it is regenerated under second regeneration conditions, particularly in the presence of excess oxygen. After separation of the second regeneration effluent, the catalyst is recycled to the cracking zone. The second regeneration effluent, on the other hand, which contains sulfur mostly in the form of anhydrous sulfite, generally has a concentration of 700-1.
It is recovered at a temperature of OO0°C and separately fed to a desulfurization reaction zone.

one of the two effluents to the bottom of the first end of the reaction zone;
Another effluent may be introduced into the lateral part of the zone, preferably above the lateral injection point of the absorbent particles.

The lateral introduction of one of the two effluents may be substantially radial or substantially tangential. These staging methods have the advantage of reducing the particle flow rate in the reaction zone and thus increasing the average contact time between the absorbent and the effluent to be desulfurized. These methods also allow for some operational flexibility as the invention must be operated with various flow rates being processed.

The contacting of the absorbent particles comprising metal carbonate with the gaseous effluent is usually carried out according to a ratio of the metal molar flow rate to the sulfur molar flow rate contained in said effluent from 0.5 to 3, preferably from 1.1 to 2. be done.

With special embodiments of the process it is possible to carry out direct recirculation of the absorbent particles in the reaction zone, but the energy released by the combustion of the incompletely combusted material is too high and the particle temperature at the end of the reaction is too large. In another embodiment, these particles are at least partially cooled at the outlet of the separation zone in a fluidized bed cooling zone before being recycled to the reaction zone, if it is evident that they are accompanied by too much rise. It's okay. Similarly, if it is clear that it is necessary,
A membrane wall cooling system located directly within the desulfurization reactor may be provided, but this system is less flexible than using a heat exchanger located on the particle recirculation circuit. This is because the latter can be completely eliminated. In the case of a heat removal exchanger arranged within the reactor, a relatively constant intensity of heat exchange is always obtained.

The invention likewise relates in particular to a device for carrying out this method. The apparatus comprises: (a) a tubular desulfurization reactor (14) of elongated shape with a first end (14a) and a second end (14b) opposite the first end; (b) an absorbent particle supply means (16) connected to the first end of the reactor; (C) at least one catalyst particle regenerator and an absorbent particle supply means (16) connected to the first end of the reactor; at least one supply means (30) for a gaseous effluent suitable for contacting the effluent with solid particles in a vessel and for circulation in a fluidized bed, and at least one oxygen-containing supply means (30) connected to said first end of the reactor. gas supply means (15); (d) a sulfur pump comprising an inlet (17a) connected to the second end (14b) of said reactor (14) and an outlet (17b) for sulfur-enriched particles; means for separating sulfur-enriched absorbent particles from a gaseous effluent subjected to
), (e) a desulphurization effluent discharge means (18) connected to said separation means (17), (f) an outlet (17b) of the separation means and a reactor (14).
sulfur-rich particle recirculation means ((20) in FIG. 1 and (33) in FIG. 2) connected to the first end (14a) of the
and (g) the recirculation means (33) and the separation means (17).
and/or solid particle extraction means (3G) (37) connected to said reactor (14).

The invention will be better understood by looking at the following drawing which shows, purely by way of example and diagrammatically, an apparatus for carrying out the process: FIG. 1 shows a fluidized bed catalytic cracking apparatus with two regeneration zones and recirculation after cooling of the absorbent particles.

- Figure 2 shows direct circulation of desulfurized absorbent particles.

According to FIG. 1, the device includes steam via line (2), hot cracking catalyst via line (3), and hot cracking catalyst via line (4).
) is provided with a riser (1) for feeding the sulfur-containing hydrocarbon feed to the bottom.

After cracking, the mixture of catalyst and effluent hydrocarbon vapors is sent to a stripping device (5).

It is supplied with steam from the line (6). The hydrocarbon vapor from which particles have been removed leaves the stripping device via line (50) and is sent to a fractionation column (not shown in the drawing).

A line (7) from the stripping device (5) conveys the spent catalyst and sulfur compounds, including coke, to the bottom of the first re-pot (8). Here, in the presence of air conveyed via line (9), partial combustion of the components deposited on the catalyst takes place under first regeneration conditions known per se. The partially regenerated catalyst then enters the second regenerator (12) via the conduit (10) (lift). This conduit (10)
is supplied with steam from line (11), while the first regeneration effluent is collected after dedusting in at least one internal or external cyclone (41) to a temperature of about 70°C.
At 0° C., it is sent via conduit (30) to the device according to the invention described below. These first regeneration effluents, which are particularly rich in hydrogen, hydrogen sulfide, incompletely burned hydrocarbons, and carbon monoxide, are generally at a higher pressure than the pressure within the first regenerator. These may be depressurized in an energy recovery turbine (13). Its inlet is connected to the cyclone (41) by a conduit (30a) and its outlet is connected to the cyclone (41) by a conduit (30a).
), and a flow rate control valve (43) is disposed therein.

The second regenerator (12) contains partially regenerated catalyst particles and is provided with a second regeneration condition known per se by means of an oxygen supply brought to the bottom of the second regenerator (12) by a conduit (40). Below, almost complete regeneration of these catalyst particles is possible. The catalyst particles are then recycled by line (3) towards the feed of the riser.

The second regeneration effluent is dedusted by an internal or external cyclone (42) of the regenerator (12). They are particularly rich in sulphite anhydride, carbonic anhydride, and generally also contain an excess of oxygen. These are at a temperature of approximately 800°C. They are sent by a conduit (31) from the outlet of the cyclone (42) of the second regenerator (12) to the desulphurization reactor (14), generally to the first half, preferably the first third, of the circulating bed. . Conversely, the effluent of the first regenerator is fed to the bottom of the end of the reactor, where the effluent of the second regenerator is preferably introduced above the dense phase present at the bottom of the reactor. are under substantially the same pressure. Effluent flow rate control valve (43) (44
) are in conduits (30) and (31), respectively.

The desulfurization reactor (14) is preferably elongated and tubular with a circular cross section. An injection means (not shown in the drawings), for example a Venturi tube, allows substantially axial injection of the first regeneration effluent, and the injection means, for example a nozzle, allows for substantially axial injection of the first regeneration effluent into the lower end of the reactor. A substantially radial injection of the second regeneration effluent into section (14a) is enabled.

At least a portion of the solid particles (Ca CO3) are connected to the pipe (
16) at this end level of the reactor, preferably between the two inlet levels of the effluent. If the excess air in the second regenerator is insufficient to ensure complete combustion of the effluent coming from the first regenerator as well as sulphation of the absorbent in the desulfurization reactor, the Supply is via conduit (1
5) may be implemented. This communicates into the reactor, preferably between the two inlet levels of the effluent.

The absorbent particles coming from the recirculation means described below are likewise passed through the conduit (2
0) is fed to the reactor (14) by conventional introduction means placed at the end of (23).

Under these conditions, the entire sorbent particles in contact with the gaseous effluent stream are combusted and desulfurized over almost the entire height of the reactor, and the reactor (14
) from bottom to top.

The desulfurized effluent is transferred to the reactor (14) at the inlet (17a).
It is separated from the particles in at least one cyclone (17) connected to the upper end (14b) and connected to the pipe line (18).
) in a recovery boiler not shown in the drawings.

The particles leave the cyclone (17) via the outlet (17b) and fall by gravity into the fluidized bed cooling enclosure (19).

This enclosure (19) has at least two flow compartments (19a) and (19b) separated by a partition (19c) in a part of its height.

The first compartment (19a) contains hot absorbent. This absorbent may be reinjected directly to the level of the lower end of the desulphurization reactor via conduit (20).

A hot particle flow control valve (21a) makes it possible to limit the amount of these particles in the reactor. This is accompanied by an overflow of these hot particles into compartment (19b). This compartment is cooled by a conventional type of heat exchanger layer (22) submerged in its bed. The cooled particles flow from the compartment (19b) to the end of the reactor (14) in a conduit (23) regulated by a flow control valve (21b).
). In this way, these valves (21
The effects of a) and (21b) allow the sorbent particles to be introduced into the reactor at a temperature suitable for both the heat level of the effluent and the combustion and desulphurization reactions.

According to another embodiment of the invention shown in FIG. 2, the particles leaving the outlet (17b) of the cyclone (17) are transferred to
33) to the lower end (14a) of the reactor. At that time, the closed storage container (8
The particle flow rate can be regulated by a mechanical flow control valve (32) connected to 0).

Direct recirculation of particles collected in the cyclone can also be carried out through the fluidization siphon.

This ensures pressure balance between the cyclone (17) and the bottom of the reactor (14).

An outlet (36), preferably at the lower end (14a) of the reactor, as a means for withdrawal of catalysts or solid particles of the usual type.
The sulfur-loaded particles may be discharged at least in part. However, they may also be introduced elsewhere, for example at the outlet (37) (FIG. 1) of the compartment (19b).

Similarly, the lower end of the reactor (14a
), but may equally well be introduced at any other point in the cycle.

EXAMPLES The invention may be understood, for example, by the following examples which illustrate the process: An atmospheric residue containing 0.7% sulfur and having an initial boiling point of 357° C.
Cracking is carried out in a fluidized bed at 525° C. in the presence of a catalyst based on zeolite Y ion-exchanged with rare earths (lanthanum, cerium, neodymium, praseodymium) under catalytic cracking conditions.

The spent catalyst is separated from the effluent and then coke 1
．． Contains 2%. Sulfur is 4.1% of this coke.

It is partially regenerated in the first regenerator at 695° C. in the presence of oxygen.

The first regeneration effluent, after separation of the particles in a cyclone, is as follows: N2 - 4086 mol/h Co = 245 mol/h CH4 =
5ic mol/hour CO2 = [i6
[ik mol/hr H2O-756 mol/hr S02+H2S-13,4 mol/hr Then the partially regenerated catalyst is introduced into the second regenerator.

Here the catalyst is injected into the bottom of the column and preset at 20°
It is subjected to a second combustion in the presence of air preheated to C. The second regeneration effluent, after being dedusted, is as follows: N2 = 7 mol air in 2019 =
1735 kmol/h Co = 0
．． 1 mole/hour C02-423 mole/hour H20 = 175 mole/hour S O2+ S
O3 = 5.7 moles/hour Average particle size 130 micrometers, specific surface area 1 m27g, 98.7% CaC
The combustion and desulfurization reactions in a desulfurization reactor in which O3-containing limestone flows as a fluidized bed are carried out under the following conditions: - First regeneration = 691 °C - Second regeneration near 72 °C - Reactor Surface flow velocity in: 12 m/s Ca/S molar flow ratio = 1,6 Reactor degree, 855 °C Contact time in reactor: 1,8 s Sulfur content of desulfurization effluent 43 p, p, m Desulfurization yield :94
% Oxygen content in the treated soot; 2% Amount of heat extracted in the heat exchanger: 2. OMW

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a flow sheet for implementing the present invention, and FIG. 2 is a flow sheet showing direct circulation of desulfurization absorbent particles. (14)...Desulfurization reactor, (14a)...Top end (
(first end), (14b)...lower end (second end)
, (15)... Conduit (oxygen-containing gas supply means), (1
B)... Pipeline (absorbent particle supply means), (17)
...Cyclone (absorbent particle separation means), (17a)
... Inlet, (17b) ... Outlet, (18) ... Pipe line (desulfurization effluent discharge means), (30) (31) ...
Conduit (gas effluent supply means), (20) (33)...
Conduit (sulfur-rich particle recirculation means), (3Ei) (3
7)...Outlet (solid particle extraction means), (19) (
80)... Cooling closed container. Patent applicant: Institut Français du Petrole

Claims (1)

[Claims] (1) A large amount of CO, hydrocarbons, etc. produced as a result of the regeneration of cracking catalyst particles containing coke, which consists of the following steps:
Process for incineration and desulfurization of gaseous effluents containing SO_2, SO_3 and/or H_2S: (a) Particle size 5-5000 micrometers, specific surface area 0
．． introducing 1 to 500 m^2/g of absorbent particles into the first end of the tubular reaction zone; (b) the surface velocity of the gaseous effluent in the reactor is 5 to 40 m/g;
to the end of the reaction zone at a temperature of 60 sec.
introducing said gaseous effluent at a temperature between 0°C and 1000°C, (c) reducing the sulfur content of said gaseous effluent and adding sulfur-enriched solid particles and a sulfur-poor gas. (d) contacting said gaseous effluent with said solid particles in a circulating fluidized bed in a reaction zone in the presence of an oxygen-containing gas under reaction conditions such that a mixture with the effluent is obtained; in a separation zone at a side end, at least partially separating said sulfur-enriched solid particles from said sulfur-poor gaseous effluent, (e) having a reduced sulfur, carbon monoxide and hydrocarbon content; A method characterized in that: collecting the gaseous effluent and (f) recycling at least a portion of the sulfur-enriched solid particles towards the first end of the reaction zone. 2. The method of claim 1, wherein a portion of the sulfur-enriched absorbent is withdrawn and a substantial molar equivalent of the withdrawn absorbent is reintroduced in the form of fresh absorbent. (3) regenerating the cracking catalyst particles in a first regeneration zone, discharging the first regeneration gas effluent at a temperature of 600-750°C, and then regenerating the cracking catalyst particles in a second regeneration zone at a temperature of 70°C;
discharging a second regeneration gas effluent at 0 to 1000<0>C and introducing the first and second regeneration gas effluents separately and at substantially the same pressure into the first end of the reaction zone; The method according to claim 1 or 2. (4) A process according to one of claims 1 to 3, wherein the conditions of step (c) are such that the sulfur weight content of the effluent is reduced by at least 70%, preferably by 80-99%. (5) A method according to one of claims 1 to 4, wherein the solid particles consist of at least one metal carbonate or at least one metal oxide selected from the group consisting of alkali metals, alkaline earth metals and mixtures thereof. . (6) The gaseous effluent and the metal carbonate or metal oxide are heated at a temperature of 750 to 100 at a molar flow ratio of metal to sulfur contained in the effluent of 0.5 to 3.
Claims 1 to 3, wherein the contact is carried out at 0°C for a contact time of 0.5 to 4 seconds.
Method according to one of 5. (7) Claims 1 to 6, wherein the solid particles contain calcium carbonate.
method according to one of the methods. (8) After the separation step (d) of the sulfur-enriched solid particles and before the recycling step, the particles are at least partially cooled in a fluidized bed cooling zone. method. 9. A process according to claim 1, wherein the oxygen-containing gas is introduced in such an amount that the decontaminated effluent contains 1 to 10% by volume of oxygen, preferably 2 to 4%. (10) A method according to one of claims 3 to 9, wherein the oxygen-containing gas is provided at least in part by the regeneration effluent of a second regeneration. (11) A method according to one of claims 1 to 10, characterized in that an oxygen-containing gas is introduced at least partially into the first end of the reaction zone. 12. The method of claim 3, wherein one of the two effluents is introduced at the bottom of the first end of the reaction zone and the other effluent is introduced at the side of the reaction zone. (13) (a) an elongated tubular desulfurization reactor (14) comprising a first end (14a) and a second end (14b) opposite the first end; (b) said reactor; (c) at least one catalyst particle regenerator and an absorbent particle supply means (16) connected to the first end of the reactor and solid particles in the reactor and effluent; at least one supply means (30) for a gaseous effluent suitable for contact with a substance and for passage in a fluidized bed, and at least one oxygen-containing gas supply means (15) connected to said first end of the reactor. (d) a sulfur-poor gaseous effluent with an inlet (17a) connected to the second end (14b) of said reactor (14) and a sulfur-enriched particle outlet (17b); Means for separating sulfur-enriched absorbent particles from
), (e) a desulphurization effluent discharge means (18) connected to said separation means (17), (f) an outlet (17b) of the separation means and a reactor (14).
sulfur-rich particle recirculation means ((20) in FIG. 1 and (33) in FIG. 2) connected to the first end (14a) of the
and (g) the recirculation means (33) and the separation means (17).
and/or solid particle extraction means (36) (37) connected to the reactor (14).
equipment for carrying out two methods. (14) comprising at least two separate gaseous effluent supply means (30) (31) connected to said first end of the reactor;
) is connected to a first regenerator of catalyst particles of the catalytic cracking device, and the second means (31) are connected to a second regenerator of catalyst particles of the catalytic cracking device. equipment. (15) Of the two supply means (30) and (31), one means connected to the bottom of the tubular reactor, and the other means connected to the side surface of the first end of the reactor. 15. Device according to claim 14, characterized in that it comprises means. (16) the recirculation means (20) (33) are solid particles located between the outlet (17b) of the separation means (17) and the first end (14a) of the reactor (14); at least a portion of the cooling enclosure ((19) in FIG.
Claim 13, characterized in that it comprises (80)) in Figure 13.
~1 device out of 15.