DE2151793A1 - Process for removing sulfur compounds in the form of sulfur oxides from gases or gas mixtures which contain one or more gaseous sulfur compounds, and a device suitable for this purpose - Google Patents

Description

DIPL-CHEM. DR. ELISABETH JUNG DIPL-CHEM. DR. VOLKER VOSSIUS DIPL.-PHYS. DR. JÜRGEN SCHIRDEWAHN PATENT LAWYERS

8 MONKS 23.

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"ftiLEKGIi 345067 TELEGRAM ADBESSE ·. IN VENT / MON NCH ε Ν TELEX 5-29686

P 6639 C (J / Me)

SHELL INTERNATIONAL RESEARCH MAATSCHAPPIJ NV,
The Hague - Netherlands

Process for removing sulfur compounds in the mold of sulfur oxides from gases or gas mixtures that contain one or more gaseous sulfur compounds, as well as one suitable device for this purpose

Priority: October 19, 1970 Netherlands No. 7015312

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The invention relates to a method for removing sulfur compounds in the form of sulfur oxides from gases • or gas mixtures that contain one or more gaseous sulfur compounds. It also concerns a corresponding one Device used in this process.

A process for removing sulfur oxides from combustion gases, in which these lemperaturen sulfur oxides through contact with an acceptor for sulfur oxides wherein are freed over 300 ⁰ C, was already described "This acceptor consists of a metal or a metal compound on a suitable carrier substance In order to prevent the solid substances inevitably present in combustion gases, consisting of soot and fly ash, from clogging the acceptor layer, the combustion gases to be treated are passed through a device that consists of a system of parallel or at least largely parallel channels Y / ands are gas-permeable and behind which the acceptor substance is located.The sulfur oxides to be removed diffuse through the walls of the gas channels and come into contact with the acceptor, while the solid constituents remain in the gas channels and are removed from the combustion gases, which with e flow through at a relatively high speed, be carried along.

The above procedure is less interesting for removal of sulfur oxides from exhaust gases that do not contain any solid components, such as exhaust gases from a Claus plant, because the used device quite expensive and its design features for such exhaust gases are superfluous. It is by far purposeful

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more massive, such processes with the help of fixed bed acceptor layers feed through. However, there is the difficulty that in this process the sulfur oxides under oxidizing

Conditions must be included and that the metal applied to the acceptor to absorb the sulfur oxides is must be in the oxidized state. Included due to their nature zv / ar combustion gases a sufficient amount of free oxygen to meet both preconditions when these gases come into contact with to meet the acceptor right from the start. Contrasted with this however, Claus exhaust gases, which are obtained after the last catalytic layer, are not only sulfur dioxide but also e.g. hydrogen sulfide. But they are free of salier matter, so that these exhaust gases after flowing through an ordinary one thermal or catalytic incinerator does not contain enough oxygen to make up all of the acceptor present to be converted into an oxidized state at the very beginning of the process, and therefore initially not absorbed sulfur * Dioxide passes through the acceptor layer.

The aim of this invention is to provide a method with fixed contact for cleaning exhaust gases, other than combustion gases, using an acceptor for sulfur oxides. Another goal is to have a procedure create, with the help of which besides sulfur oxides also others Sulfur compounds, e.g. hydrogen sulfide, from items to be cleaned Exhaust gases are removed. The aim of this invention is also to provide a continuously feasible for such purposes Procedures to be made available.

The invention accordingly relates to a method of removal of sulfur compounds in the form of sulfur oxides

from gases or gas mixtures which contain one or more gaseous sulfur compounds, using a metal • and / or a metal compound-containing acceptor for SChv? e ~ feloxyde under oxidizing conditions at temperatures LAT 325 ⁰ C and 475 ⁰ C, wherein the acceptor is regenerated after its loading under reducing conditions in the same temperature range, which is characterized in that one or more fixed acceptor layers are used for the gases or gas mixtures that contain gaseous sulfur compounds and are free of solid components, one of which, or at least one layer a part of the same is contacted with the gas to be treated, another layer or at least a part of the same with a reducing gas and a third layer, or at least a part of the same is contacted with an oxidizing gas, that the gases to be treated after the loading of the previous layer or one Part les of the same, are fed into that layer or at least that part which has been in contact with the oxidizing gas while the loaded layer or its loaded part comes into contact with the reducing gas, and each

the or

nige layer or at least part of it, / that with the reducing gas has been in contact with the oxidizing gas.

For the sake of brevity, the gases or gas mixtures that contain gaseous sulfur compounds are free of solids Components are referred to as "gases to be processed",

In order to prevent the different types of gas in one layer or at least part of it from being mixed up with each other

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come into contact, what with consideration of the performance and security of the method is undesirable, according to the invention this is preferably carried out in such a way that one layer or at least a portion of those that came into contact with a reducing gas before being re-exposed to the oxidizing gas comes into contact, is first treated with an inert gas. A loaded layer or its loaded part, first treated with an inert gas before coming into contact with a reducing gas In the present invention, inert gas is understood to mean a gas which is in contact with that present in the layer or a part thereof Gas or with that introduced afterwards. Gas does not enter into any undesired reactions and which in the layer or part of the same acceptor contained in no undesirable. Way influenced. * The percentage of free oxygen in such a gas should generally be low. The inert gas used can a.B. from nitrogen, carbon dioxide and / or water vapor exist.

Any gas mixture that contains free oxygen is suitable as the oxidizing gas. However, it is preferred that the proportion of the free oxygen does not exceed 10 percent by volume, to prevent overheating and thereby destruction of the acceptor. A suitable gas mixture can be obtained by combustion of hydrocarbons with a low evaporation temperature, such as methane or natural gas in oxygen or air obtained using a small excess in relation to the amount necessary for complete combustion. Bad Combustion gas also contains a high proportion of water vapor,

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which is a maximum of 66 percent by volume. This water vapor content is particularly favorable if the oxidizing gas after 'passing through the acceptor layer to be oxidized with the for processing the loaded layer used reducing gas is combined. For this particular further application of the oxidizing gas after flowing through the acceptor layer, it should preferably contain less than 2 percent by volume of oxygen. Eg it is also possible that from the acceptor layer which has just been oxidized outflowing exhaust gases which still contain free oxygen with those to be processed in the process according to the invention To unite gases. It is of course also possible to use some of these exhaust gases for both of the purposes mentioned.

It is also possible to add up to 90 percent by volume of water vapor to the oxidizing gas, especially in the case where this gas has passed through the oxidizing gas

Acceptor layer is combined with the reducing gas.

With a view to a longer service life of the acceptor, it is advantageous to pass the reducing gas through an acceptor layer or to direct at least part of this layer in countercurrent to the direction of flow of the gases to be treated. the other gases, namely the gases to be treated, the oxidizing gas and the inert gas, can all pass through an acceptor layer or at least be passed through part of such a layer in the same direction. Sometimes however it is it is desirable to use the oxidizing gas also in the counter flow, e.g. in the treatment of Claus exhaust gases.

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These latter exhaust gases are obtained in the Claus process at a temperature which is usually well below 325 ^° C. The fact that the oxidizing gas flows through an acceptor layer or at least part of this layer in countercurrent to the Claus exhaust gases to be processed ensures that the beginning of the mentioned layer or relevant sub-layer has a considerably higher temperature than its end, so that the exhaust gases to be processed be heated by the layer itself to the desired loading temperature.

The process according to the invention can be carried out in various ways, namely periodically, semi-continuously or continuously. In the periodic or pendulum method, three separate acceptor layers are preferably used. It is advantageous to use fixed layers with radial flow. It is also possible to use four acceptor layers in two parallel groups each. In this case, the total time required for contact with the acceptor layer by the reducing and inert gas as well as by the oxidation gas should be the same. This enables the pendulum method to be carried out in such a way that two layers with the come into contact with the gas to be processed (loading phase ) _/ while the other two layers come into contact with the reducing gas (reduction phase) and with the oxidation gas (oxidation phase) When this process is carried out semi-continuously, the various phases in the individual acceptor layers are related to each other forgotten

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In another variation of this procedure, a single, firmly arranged cylindrical acceptor layer applied, which is divided into three acceptor zones. These zones are not connected to each other and come one after the other with the to be treated gases in contact, the direction of rotation with respect to the successive contacts with the mentioned Gases is the same as those in which the listed zones come into contact with the oxidizing gas.

Boi the continuous shaping of the applied erfindungsge- w extent procedure% iia a single fixedly arranged cylindrical acceptor, which is divided into a plurality of zones -radialen. These zones are not connected to one another and are continuously in contact with the gases to be treated in an uninterrupted sequence, this contact only taking place partially at the same time, in front of the zones which are in contact with the gases to be treated in the manner shown found to be regenerated ^ by the fact that they are brought into contact with the reducing gas and then with the oxidizing gas, this contact likewise taking place in an uninterrupted sequence and only partially at the same time.

To prevent the different gases from being introduced into the same zone (s) at the same time, this continuous mode of operation is preferably carried out in such a way that that part of the cylindrical acceptor layer which is in contact with the gases to be treated is separated from other parts of the cylindrical acceptor layer that is regenerated by at least one, or better by two or more

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BAD ORlGfNAL

radial zones is separated. That part of the cylindrical layer that is exposed during regeneration with an oxidizing gas is in contact is in the same way from the other part of the mentioned layer, which is during the regeneration is in contact with a reducing gas, separated by at least one or better two or more radial zones.

The cited configuration of the method allows continuous operation because certain parts of the Cylindrical acceptor layer divided into radial zones continuously forms a loading or regeneration phase are located, the latter in turn being divided into two separate phases. By making sure that at least an acceptor zone that separates the various process phases prevents the various gases from passing through the acceptor layer come into contact with each other and cause undesirable reactions *

In order to bring the different zones into contact with the different types of gas in an uninterrupted pole, For example, the fixed acceptor layer can be rotated in one Reactor housing be attached. According to a preferred "execution according to the invention, however, a stationary, solid acceptor layer is applied while the gases are being introduced that they come into contact with all acceptor zones in uninterrupted sequence, as explained in more detail below will.

Since the use of a metal and / or a metal compound containing acceptors the removal of sulfur

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Compounds in the form of sulfur oxides under oxidizing In other words, in the presence of oxygen or an oxygen-containing gas, it is sufficient for that part of the cylindrical layer that comes into contact with the gases to be treated again after regeneration comes that they only pass through a single zone of that part of the mentioned cylindrical layer, which comes into contact with an oxidizing gas during the regeneration, is separated.

Gases or gas mixtures which contain gaseous sulfur compounds and are free of solids, can contain hydrogen sulfide and / or sulfur dioxide. Surprisingly, it has been found that, under the conditions used in accordance with this invention, hydrogen sulfide is removed in the form of sulfur dioxide. This is a great advantage, which makes it possible, for example, to subject the exhaust gases from sulfur-producing plants according to the Claus process directly to the process according to the invention, bypassing the conventional incinerator for such exhaust gases. Oxygen or an oxygen-containing gas, for example air _y , must then be added to such exhaust gases in order to create an oxidation medium. However, if it is desired for certain reasons, it is still possible to burn the exhaust gases from the systems mentioned in a thermal or catalytic incinerator and then the combustion gases freed from hydrogen sulfide, with the addition of a further amount of oxygen or an oxygen-containing gas, the one according to the invention To submit to proceedings.

If the Claus exhaust gases have been fed to a combustion, then they must be cooled down to a temperature range,

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in which the method according to the invention is carried out. The cooling can be done by indirect heat exchange or by injecting steam or water into the hot gases. A particularly favorable method is based on the combination of the burned Claus exhaust gases with another combustion gas. There If the latter gas also contains free oxygen, this combination of the two gases serves a double purpose, namely cooling the hot Claus gases and the supply of the oxygen required for loading. The combustion gas is preferred freed from solid particles with the help of an electrostatic precipitator. The Claus Ga3e are according to a ratio from 0.02 to 1.0 volume parts to one volume part of the combustion gas diluted.

It is also possible that the gases to be treated only contain hydrogen sulfide or other sulfur compounds, which can easily be converted into sulfur oxides via a metal compound. Gases produced as a result of their treatment do not contain enough oxygen, should be mixed with oxygen or an oxygen-containing «! gas are mixed before they are subjected to the process according to the invention will. One possible way of obtaining the free oxygen has already been explained in detail above.

Contain the acceptors used according to the invention preferably ICupfer and / or ^ -upferoxyde as metal and / od & r lie— tall connection. Activated aluminum oxide, e.g. Gararaa aluminum oxide or a mixture of

used,
Gamma and alpha aluminum oxide / although basically any solid substance that is temperature-resistant and hardly, can be considered

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if at all, under the prevailing conditions Sulfur oxides are attacked »As examples are mentioned:

Bauxite, silicon-aluminum oxide and silicon-magnesium oxide.

Acceptors consisting of copper and / or copper oxide, preferably on activated aluminum oxide as a carrier substance, were used for the removal of sulfur dioxide from gases under; Oxidation conditions at temperatures above 30O ⁰ G found very suitable. Under the conditions in which sulfur dioxide is chemically bound by the acceptor, sulfur trioxide is also removed from the gases, while, as already stated above, it was found that hydrogen sulfide is oxidized to sulfur dioxide, which is then absorbed

The copper content of the acceptor can, also depending on the specific surface of the applied substance, vary within wide limits. As a rule, this content is 1 to 15 percent by weight, based on the finished acceptor. Optimal Results are achieved with acceptors that contain 4 to 10% by weight of Kxipfer.

Mechanically very strong acceptors contain 1 to 6 weight percent glass in the carrier substance. Acceptors of this type are obtained by bringing the carrier substance into the required shape with glass powder, for example glass powder, glass powder or glass frit, together with a suitable binding agent. The molded material (Strangpreosformlinge, spheres, pills, or possibly ceramic moldings) is then preferably calcined at temperatures above 780 ⁰ C, 800 to 1300 ⁰ C. After the briquettes have been calcined and cooled, the

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'chose metal compound applied by impregnation. The calcination is then repeated, specifically at temperatures between 500 ^° C. to 600 ^{° C.}

The high superiority of the acceptors of the above type is based on the fact that, after being loaded with sulfur oxides with the formation of metal sulfates at a temperature equal to or practically equal to that temperature which the uptake took place can be regenerated. Operation at loading and regeneration temperatures that hardly differ from each other is not only beneficial from a thermal economic point of view, but is also very important for the lifetime of the acceptor. For an economically working process it is essential that the accepted acceptor can regenerate a few hundred times or more without particularly losing its stability and activity. It should It will not be easy to achieve such a long service life with acceptors that are in a proportionate manner each time they are regenerated have to be heated and / or cooled over a wide temperature range, since the chemical and physical stability of the a metal and / or a metal compound containing acceptor can be significantly affected by these types of temperature changes.

The removal of sulfur compounds as sulfur oxides under oxidizing conditions, namely in the presence of oxygen at temperatures between 325 and 475 G ^{0 0} C are preferably temperatures of 375 ⁰ C bi3 430 ° C applied. The regeneration under reducing conditions takes place in the same temperature range. Loading and reduction

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are preferably carried out in this area at the same or practically "the same temperatures." This means that the reduction of the loading occurs without intermediate cooling or heating of the acceptor layer or a part of this layer Local temperature fluctuations of 50 ^° C. and more can easily occur during loading. As a result, the temperature of the layer or its part will usually be higher at the end of the loading than at the beginning the supply of colder regeneration gas can be removed.

The reducing gas used for regeneration can consist of hydrogen or a hydrogen and / or carbon monoxide containing gas mixture exist. It is also possible to use light hydrocarbons such as methane, ethane, propane or their mixtures

· Ι

see, or even natural gas or the direct distillation to use overhead distillates from petroleum. If required, can these reducing gases with inert gas such as nitrogen and / or water vapor, or .with the oxidizing gas with low Oxygen content, as it flows out of the oxidized acceptor * layer, which has already been explained above, applied diluted will.

In the regeneration, as in the invention Procedure, two phases are to be distinguished. In the first phase, the acceptor saturated with metal sulfate becomes treated with the reducing gas. In addition to a small amount of metal oxide, mainly metal and / or

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Metal sulfides formed. In the second phase the metal and / or the metal sulfide are oxidized. Trap the applied metal "Is copper, the following reactions take place in the oxidation phase

Cu + 1/2 O ₂ > CuO

CuS + 2 1/2 O ₂ ^ -CuO + CuSO.

After the oxidation phase, the acceptor is ready to accept new amounts of sulfur oxides. As from the above As can be seen from the reaction equations, it is advantageous to carry out the regeneration in such a way that the CUpS content is as small as possible after the reduction phase, because half of the copper bound as sulphide is no longer available to absorb the sulfur oxides.

The loading takes place under oxidizing conditions. The content of free oxygen in the gases to be treated is preferably chosen so that after the conversion of the gaseous Sulfur compounds, besides the sulfur oxides, in Sulfur dioxide is the molar ratio between what is still present free oxygen and the total amount of gaseous sulfur compounds that are present as sulfur dioxide, 1 or is more than 1. On the other hand, however, the amount of oxygen generally does not become much for economic reasons chosen higher than it is for the implementation and uptake of all gaseous Sulfur compounds is stoichiometric.

It should be noted that during the regeneration of the tletallsulfat-laden acceptor a gas with a-ü relatively high sulfur dioxide content is developed.

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The method according to the invention is therefore very well suited for the treatment of large quantities of gases or gas mixtures Ίηίΐ a relatively low concentration of gaseous sulfur compounds. The gas rich in sulfur dioxide can then be processed into elemental sulfur or sulfuric acid in any known manner. Y / ith the inventive method for Claus off-gases used, then the sulfur dioxide-rich regeneration gas to the actual Claus process can v / ground in a simple Heise fed back.

In the further processing of the free sulfur dioxide it is sometimes advantageous to use those obtained in the regeneration To cool gases rich in sulfur dioxide until condensate forms and to add steam to the resulting condensate strip to release the sulfur dioxide from it.

. The invention also relates to a suitable device for carrying out the new method of removal of sulfur compounds. A suitable device for semi-. continuous implementation of the process consists of a cylindrical housing, the inside in at least three not interconnected related chambers is divided. -Each of these chambers is on the top and bottom of the case with an inlet or Provided outlet opening BEZW a common gas inlet. Have gas outlet. These openings are placed in the upper and lower floors so that they are both on the inlet side as well as on the outlet side of the housing with a single rotatable disk each sealed gas-tight can be. Both discs are each provided with a single opening, which when turning the mentioned

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Disc comes into communication with the opening or a part of the opening of one of the mentioned chambers, the openings of the mentioned discs each being in communication with the openings of the same chamber. Said rotatable disk is preferably on the outside of the cylindrical housing inside the gas inlet respectively. Gas outlet attached. For this purpose, the inlet is bzv /. The outlet is conical in shape and its widest edge is attached to the top and bottom of the housing. The openings in the rotatable disks and the chambers can have any desired shape. They are preferably curved and slot-shaped and preferably extend over an arc of approximately 120 ^a . As a rule, circular openings are only used in the rotatable disks and not in the chambers. In order to enable the rotatable disks to be rotated after the acceptor has been loaded in a chamber, the device is provided with a device for rotating the disks in a mutually unchanged position. In addition, each chamber should be provided with at least one further gas inlet or gas outlet for the reducing and oxidizing gas required to regenerate the acceptor as well as for the inert gas. ' ^J

A device of the type listed above is in the Figures 1 and 2 of the drawing are shown.

The continuous: implementation of the invention The method can expediently be carried out in a device which consists of a cylindrical housing whose Inner part contains a plurality of radial chambers that are not connected to one another, as well as one or more separate ones

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Gas inlets for the supply of the gases or gas mixtures to be cleaned, for the reducing gas and oxidizing gas, and one or more gas outlets for the said types of gas and one A device that has the said chambers in an uninterrupted sequence and only partially at the same time as the inlet and outlet one of said gases connects. ;

The device for connecting the said chambers in an uninterrupted sequence, with only partially simultaneous connection, both to the inlet and to the outlet of one of the gas types mentioned, consists of two discs which are rotatable in a mutually constant position. These disks are provided with two or more curved sole-like openings, one of these disks being arranged in the upper part of the cylindrical housing and the other in its lower part. Each of the discs includes the said chambers on one side from a gas-tight, while adjacent to the other side to a system of three or more concentric annular channels, which f between said rotatable Sehei- be and the upper and lower outer side of the cylindrical housing attached is. Each annular channel of this system is thereby connected to one or more of the separate gas inlets / gas outlets, the slot-shaped openings, which only extend over part of the radial chambers, being arranged so that each of them communicates with only a single channel, while the position of the slot-shaped openings in the upper and lower disk largely corresponds to one another. The rotatable disks are preferably connected to a shaft which is attached inside the cylindrical housing and which is driven in a manner known per se.

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Since it is possible to use the outlets of several types of gas unite, one of the rotatable disks preferably has three slot-shaped openings which extend over a number of chambers extend, and the other disc has at least two such openings · An identical number of channels should these Openings correspond. One of the disks preferably has two; relatively long openings and a relatively short Ze opening specially provided for the introduction of the oxidizing gas into the cylindrical housing for a short period of time is. In order to also allow the introduction of an inert gas, the system comprises the circular channels on the Inlet side of the gases preferably four channels with suitable gas inlets.

In connection with the fact that some types of gas can be withdrawn together, the length of the slot-shaped Openings, the position of which largely corresponds to one another in the upper and lower panes, be unequal · In this way the introduced inert gas can escape through the outlet intended for another gas. To introduce inert gas after the loading phase and before the oxidation phase, one of the disks is also provided with two short openings, which are arranged practically diametrically opposite one another and both are connected to the comparatively narrowest channel of the system of four channels. This will With the help of these openings and the slit-shaped openings in the other disc, in one case the gas inlet of this channel with the gas outlet of the outer channel and in the other case with the gas outlet ctes inner channel of the other system of concentrated

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- 20 days, circular channels connected.

On this yieise can also be the inlet of the circular Channel, with which the relatively short slot-shaped opening coincides, partly with the outlet of the centric one Channel of the other system of concentric circular channels and partially connected to the outlet of one of the other channels of this latter system.

Apparatus of the above type is shown in Figures 3-6.

The invention is further explained with reference to the accompanying drawings.

Pig. 1 represents one for the application for the according to the invention Method suitable device that contains three separate acceptor layers.

Fig. ' 2 shows a section along the line A-A'der in FIG Fig. 1 represents the device shown.

3 is a schematic representation of an apparatus which contains a plurality of radial, non-interconnected ^{chambers 1} for the acceptor material.

FIG. 4 is a plan view of the upper rotatable disc of the device of FIG. 3.

Figure 5 is a top plan view of the lower rotatable disk the device according to FIG. 3.

Fig. 6 is a top plan view with partial section through

Device according to FIG. 3.

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In Pig. 1A, the reference numeral 1 denotes a cylindrical reactor which, by means of three radially arranged separating, walls that extend from an upper outer wall 3 to a lower outer wall 4 are not connected to one another in three standing chambers is divided. The broken lines 2a, 2b, and 2 £ denote the joints between these vertical partitions with the cylindrical side wall of the reactor 1 · Both the upper surface 3 and the lower surface 4 each these chambers, which contain the acceptor substance for the absorption of sulfur compounds in the form of sulfur oxides, is provided with at least one opening for the inlet or outlet of the gases to be treated. The gases to be treated are fed through the line 5> which is connected to a conically widened extension 6, which forms the gas inlet. The conical extension 6 is sealed gas-tight by a rotatable disc, which, as will be discussed further, with a single opening is provided. Depending on the position of this turntable 7, it is possible to use the gases to be treated with the help of this rotatable disc, which seals the said chambers gas-tight, first in one and then in another To direct chamber. For the outlet of the `` gases to be treated '' is

the lower part of the reactor is provided with the same device as for the supply of the gases to be treated. For experts in this area it is now clear that the opposite Direction of flow of the gases through the reactor is possible. A rotatable disc with a single opening 8 seals the underside of the chambers in a gas-tight manner. The position of the lower disk matches that of the upper disk 7

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so that the Gaoe introduced into a certain chamber they can exit on the other side through the opening in the lower surface 4 and the rotatable disc 8. the Clean gases thus reach a conically shaped extension 9, which forms the gas outlet, and are drawn off through the line 10 In FIG. 2, identical parts are denoted by the same reference numerals. With 3 is the top surface of the cylindri ~ see reactor 1 labeled. The disk 7 is rotatably mounted on this upper surface 3 and is gas-tight. The dashed lines 2a, 2b_ and 2 £ are the partitions that make up the interior of the Divide reactor 1 into three equal, non-communicating chambers. The top surface 3 of each chamber is provided with a curved and slot-shaped opening 20 which extends over an arc of about 120 °. The rotatable Disk 7 is provided with an identical opening 21, and in the position shown the gases to be treated are in

the chamber delimited by the partitions 2a and 2c_ is introduced.

The disk 7 can be connected to the disk 8 on the other side of the reactor by a shaft, the Opening in the latter disk with the opening of disk 7 P * ^ matches, so that the gases to be treated by the now

open chamber can flow · In Figure 2 is the passage . denoted by 22 for said shaft.

Haeh the loading of the acceptor in a particular chamber the disk 7 as well as the disk 8 coupled to it is rotated by 120 °, so that the next chamber for the the gas to be processed is opened The direction of rotation is selected so that the chamber that is now open is the

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tion gas that has been in contact. Contains acceptor. The chosen one Execution of the device ensures at least a continuous

>
extensive uptake of the sulfur oxides.

To regenerate the charged acceptor is the reactor 1 is provided with at least one gas inlet 12 and one gas outlet 16 for each of the three chambers. In the illustrated embodiment v / ground the reducing gas required for regeneration, the oxidizing gas and the inert gas (steam) through pipes 13 »15 and 14 supplied and withdrawn through lines 19» 17 and 18. The various lines are with the required Valves equipped using the same inlet or outlet. It is of course also possible to do any of the above To feed in Gaae through its own inlet and withdraw it through its own outlet.

The rotatable disks 7 and 8 can be used after loading be rotated with the aid of a device known per se. This facility was shown in the schematic drawing omitted. It is also possible to design the conical lugs 6 and 9 so that they over the said rotatable disks cover and form a direct gas-tight connection between the upper surface 3 and the lower surface 4 of the reactor. Instead of the openings shown, round openings can also be used. A reactor modified in this way is shown in the drawing 1B, in which part of the upper conical extension and the cylindrical side wall in section are shown to illustrate the rotatable disc and a chamber defined by two radially mounted partitions.

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ι ι ο ι / 3 ο

It is clear to those skilled in the art that these chambers with the necessary grids or another corresponding one Means must be provided to prevent it from falling out to prevent the acceptor material from the chambers.

In Figure 3, 29 is the cylindrical housing of the device indicated, the middle part of which forms an open cylindrical cavity which is delimited by the wall 34. As well as the upper and lower ends of the acceptor space 33 are sealed by the rotatable disks 36 and 41 provided with slit-shaped openings (see FIGS. 4 and 5) Disk 38 has two large curved, slot-shaped openings 39 and 40 and a smaller opening 77, while the upper Disc has two large and one smaller slot-shaped opening 42, 43 and 81. The top disc also has two small openings 84a and jb, which are arranged practically diametrically opposite one another. The listed openings of the upper Disc are with many 'annular channels 44, 45 »46 and in connection, which between the rotatable disc 41 and the upper wall 31 of the cylindrical housing 29 are arranged. These annular channels are formed and delimited by the outer cylinder wall 30, the partition walls 48, 49 and 50 and the inner cylinder wall 34 «Each annular channel has one Plurality of inlets and outlets for gases; Inlet or outlet 52 belongs to channel 44, inlet or outlet 56 to channel 45, inlet or outlet 53 plus channel 46 and inlet or Outlet 54 to channel 47 · In the position of the disk 41 shown, the cylinder space 33Jb with the channel 47 is through the opening 42 in connected to the disk, the cylinder space 33a is similar

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Way through the opening 43 in the same disc with the channel 44 connected. The remaining channels of the system are made with the help of the sighting rings 61b_ attached to the lower surface, and the sealing rings 61a, which press against the upper surface of the disc 41, sealed gas-tight, the hinge in annular Carriers 57 »58a, 58b_, 58c, and 59 are arranged.

The openings in the lower one stand in a similar fashion Disc with a system between the rotatable disc 38 and the lower wall 32 of the cylindrical housing 29 connected by annular KknL ^ on. This lower annular Channels are formed and limited by the outer cylinder wall 30, intermediate plates 82 and 83 and the inner cylinder wall 34 · Each annular channel has an inlet or outlet for gases; Inlet or outlet 66 belongs to channel 63, Inlet or outlet 68 to channel 64 and inlet or outlet 67 to the channel 65 · In the position of the disk 38 shown, the cylinder space 33b is located. in open connection with channel 65 through the opening 39 'in a similar manner, the cylinder space 33a is in open communication with the channel 63 through the opening 40 in FIG the disc, the remaining channels are with the help of the sealing rings 72b_, which press against the upper surface and the sealing rings 72a, which press against the lower surface of the disk 38, are gas-tight completed, the rings in annular carriers 69, 70a, 70b_ and. 71 are arranged.

The rotatable disks 38 and 41 are by a pressing mechanism strongly against the sealing rings 72b_ and 61b pressed · This pressing mechanism 51 can consist of a small, spring-loaded wheel, of which a certain number on the

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outer and inner circumference of said discs was arranged.

It should be noted that the discs 41 and in the drawings 4 and 5 are shown in the position in which a gas introduced through a certain opening through a certain part of the non-communicating one Chambers of divided cylinder roughness flow and this tree on the opposite side through a corresponding one Opening can leave. From the fact that the two 3uL.ciben rotate continuously during operation, in proportion but remain in the same position with respect to one another, you see that other parts of the entire acceptor constantly come into contact with the supplied gases »The supplied gas will distributed in the chambers by distributor plates 62 provided for this purpose. These plates 62 are also intended to prevent the acceptor is entrained with the gas flowing in from below. The grids 85 are installed in the lower part of the chambers, which prevent the acceptor from falling out.

In FIG. 6, which shows a plan view with partial sections to show several planes of section, 85 ⁷ denotes a radial chamber. The interior of the cylinder is divided into a large number of such chambers, which are separated from one another by gas-impermeable walls 86. The radial chambers extend as far as the inner cylinder wall 34, which delimits the empty cylindrical space 37. The annular supports 57 »58a _r b_ and s. And 59 extend over the chambers 85 and they are radially connected to corresponding supports 60 which extend over the gas impermeable walls 86 are attached. The distances between the

20 * 117/1356

shaped supports 3ind the width of the annular channels 44, 45 » 46 and 47 the same. The rotatable disc (not shown here) rotates over these supports. The head of the reactor is through the top wall 31 completed and with a variety of inlets respectively omissions 52, 55, 54 and 55 for the different ones Provide channels.

The rotatable disks 38 and 41 are driven by a drive mechanism 73 (see Fig. 3) set in rotation. This mechanism consists of the shaft 73a, the bevel gears 73Jb and 73.C, the shaft 73d, and the gear 73.C ^ eIel: ce ait a toothed ring 73f engaged on the rotatable disk 38 is attached near the cylindrical wall. Similar tools are also provided for the rotatable disk 41. The V / ellc 73a passes into a shaft 74 which is mounted eccentrically in the cavity 37 and is provided with a bevel gear 74a. The gear 74a stands over a bevel gear 74b_, a shaft 74c. and a gear 74d. with the toothed ring 74e_ in engagement. The waves 73d. and 74c. are passed through the openings 35 and 36 of the cylindrical inner wall 34 in a gas-tight manner.

209817/1356

Claims (28)

- 28 patent claims: 1. A method for removing sulfur compounds in the form of sulfur oxides from gases or gas mixtures containing one or more gaseous sulfur compounds, using a metal and / or a metal compound containing acceptor for sulfur oxides under oxidizing conditions at temperatures from 325 ⁰ C to 475 ⁰ C, the aliseptor being regenerated after its loading under reducing conditions in the same temperature range, characterized in that one or more fixed acceptor layers are used for the gases or gas mixtures which contain gaseous sulfur compounds and are free of solid components, of which one layer or at least part of it is contacted with the gas to be processed, another layer or at least part of it is contacted with a reduction gas and a third layer or at least part of it is contacted with an oxidizing gas that is to be processed en gases after loading the previous layer or part of it _: in that layer or * at least that part fed in. which has been in contact with the oxidizing gas while the loaded layer or its loaded part is in contact with the reducing gas the or comes and that layer or at least part of it, / the with has been in contact with the reducing gas, is brought into contact with the oxidizing gas. 2. The method according to claim 1, characterized in that the layer or at least part of the same with a Has been in contact with the reducing gas before the subsequent 209817/1356 low contact with the oxidizing gas is first treated with an inert gas. 3. The method according to claim 1 or 2, characterized in that the loaded layer or its loaded part "is first treated with an inert gas before contacting with a reducing gas". 4 · The method according to claim 2 or 3 »characterized in that that this inert gas consists of nitrogen, carbon dioxide or water vapor. 5. Method according to one of claims 1-4, characterized in that that the reducing gas is in countercurrent to the flow direction of the gases to be processed through the acceptor layer or at least part of it is performed. The method according to one of claims 1-5, characterized in that the gases to be treated and the oxidizing gas are passed in the opposite direction of flow through the acceptor layer or at least part of the same. ^: 7. Method according to one of Claims 1-6, characterized in that that at least three separate acceptor layers are used « 8 · The method according to claim 7 »characterized in that four acceptor layers are arranged in two parallel .Gruppen are applied, the entire for the contact of an acceptor layer both with the reducing gas and with the loading time required for the inert gas and the oxidizing gas is » 269817/1356 9. The method according to any one of claims 1-6, characterized in that that a single, firmly arranged, cylindrical, in three non-connected Äkzeptorzones divided acceptor layer is applied, the zones successively brought into contact with the gases to be treated and the order in which the zones are successively brought into contact with said gases will be the same as in the case of touching the said zones with the oxidizing gas. * 10. The method according to any one of claims 1-6, characterized in, that a single, fixedly arranged cylindrical «, in a multitude of acceptor zones that are not connected to one another divided acceptor layer is applied, the zones continuously with the gases to be treated in an uninterrupted sequence and only partially in contact at the same time, according to which the zones that are to be processed Gasen'in contact, are regenerated, namely by renewed contact in an uninterrupted sequence ) and only partially simultaneously with the reducing gas and the oxidizing gas. ^ 11. The method according to claim 10, characterized in that that that part of the cylindrical acceptor layer that is in contact with the gases to be processed is affected by the other Ren! part of the cylindrical layer that is being regenerated, at least by one, but preferably by two or more radial Zones away, and that part of the cylindrical layer which is covered with a during regeneration 20S817 / I356 oxidizing gas is in contact, in a corresponding manner by at least one, but preferably by two or more radial © zones from the other part of said layer, which are in contact with a reducing gas during regeneration is »separated trird« 12. The method according to claim 10 or 11, characterized in that the one of the cylindrical layer, the comes into contact with the gases to be treated again after regeneration, only through a single zone of that part the cylindrical layer is separated, which is in contact with an oxidizing gas » 13 · Method according to one of claims 1-12, characterized in that the gases, the gaseous sulfur compounds contain and are free from pesticides, contain hydrogen sulfide and / or sulfur dioxide. 14 · Method according to claim 13 »characterized * that the gases to be treated represent Claus exhaust gases, which Oxygen or an oxygen-containing gas has been added » 15 · The method according to any one of claims 1-13 »characterized in that that the content of free oxygen in the gases to be processed is chosen so that after the implementation of gaseous sulfur compounds, with the exception of sulfur oxides, in shelf dioxide the molar ratio between the free oxygen still present and the total amount of sulfur compounds, which are present as sulfur dioxide is 1 or greater than 1. 209817/1356 16. An apparatus for performing the method according to claim 1, characterized in _t that it consists of a zylindrisehen housing consists whose inner part is divided into at least three non-communicating chambers, these chambers on the head or bottom of the housing with an inlet opening or »Outlet openings are provided * which have a common gas inlet or gas outlet, so that these openings can be sealed together in a gastight manner at the top or bottom with the help of a single rotatable disk on the inlet side of the housing and in a corresponding manner on the outlet side of the housing that each disk is provided with an individual opening which, when the disk is rotated, is connected to the opening or a part of this opening of one of the said chambers and that the openings in the two disks mentioned are connected to the openings of the the same chamber are in communication. 17 · Device according to claim 16, characterized in that that the rotating disc on the outer surface of the cylindrical " drischen housing is arranged within a gas inlet or gas outlet, that the gas inlet or gas outlet is conical and that it is with its widest edge is connected to the upper and lower case back. 18. Apparatus according to claim 16 or 17, characterized in that that the openings in the rotatable discs and in the chambers are curved and slot-shaped and extend over a Extend an angular bend of approx. 120 °. 209817/1356 19 · Device according to one of claims 16-18, characterized characterized in that they are provided with a device for rotating the Disks is equipped in a mutually unchanged position. 20 · Device for carrying out the method according to An ~ Claim 1, characterized in that it consists of a cylindrical housing, the inner part of which has a plurality of radial, non-communicating chambers, one or more separate gas inlets for the supply of the gas to be treated Gases or gas mixtures, for the induction gas and for the oxidizing gas, one or more separate gas outlets for said gases as well as a device for connecting said chambers in an uninterrupted sequence with only partial simultaneous connection of the inlets and outlets contains one of the gases mentioned. 21. The device according to claim 20, characterized in that that the means for connecting said chambers in an uninterrupted sequence and only partially simultaneously both with the inlet as well as the outlet of one of the V - th gases from two in a mutually constant position rotating disks, which are provided with two or more curved, slot-shaped openings that one of the disks at the head end, the other at the bottom of the cylindrical housing, that each of them the said chambers one side closes gas-tight, that the other side to a system of three or more concentric, ring-shaped Channels bordered between said rotatable 209Ö17 / 1356 Disc and the upper "or lower surface. Of the cylindrical Housing is attached so that each annular channel of this system with one or more of the separate gas inlets or Gas outlets is connected that the slot-shaped openings, which only extend over part of the radial chambers, are arranged so that each opening communicates with only a single channel, and that the slot-shaped openings genes in the upper and lower discs largely correspond to one another in terms of position. 22. The device according to claim 21, characterized in that that the rotatable disks are connected to a rotatable shaft present in the interior of the cylindrical housing, and that the latter is driven in a manner known per se. 23 · Device according to claim 21 or 22, characterized in that that the one rotatable disc has at least three slot-shaped openings which extend over a number of chimneys. stretch, and that the other disc has at least two such openings 24. The device according to claim 23 »characterized in that that one of the rotatable disks two relatively long and has a relatively short slot-shaped opening. 25 · Device according to one of claims 21-24, characterized in that the system of circular channels on the Gas inlet of the housing from four channels with the associated There are gas inlets. 209017/1356 -55.- 26. Device according to one of claims 21-25, characterized in that the length of the slot-shaped openings, 'Their position in the upper and lower disk is largely one another corresponds to is unequal. 27 · Device according to claim 25 or 26, characterized in that a disc with two short slot-shaped, im essentially diametrically opposed openings is provided, both of which have the relatively narrowest channel of the system of four channels communicating that the gas inlet of this channel through these openings and the slit-shaped Openings in the lower disk in one pall with the gas outlet of the outer channel and in the other with the Gas outlet de3 inner channel of the other system of concentric circular channels communicating. 28. Device according to one of claims 24-27, characterized characterized in that the inlet of the circular channel with the relatively short slit-shaped opening communicates, in part, with the outlet of the centrally located channel of the other system of concentric annular Channels and partially communicating with the outlet of one of the other channels. 209817/1356 Blank page