Process for the treatment of sulphide-containing waste

The invention relates to a method for treating a waste liquor from a liquor wash using an oxidation reactor and a corresponding plant and a corresponding oxidation reactor according to the respective preambles of the independent claims.

State of the art

Olefins such as ethylene or propylene, but also diolefins such as butadiene and aromatics can be produced from paraffins by steam cracking. Corresponding processes have been known for a long time. For details, refer to specialist literature such as the article "Ethylene" in Ullmann's Encyclopedia of Industrial Chemistry,

Online edition, April 15, 2007, DOI 10.1002 / 14356007. a10_045.pub2, referenced.

During steam cracking, what is known as cracked gas is obtained which, in addition to the target products, contains unconverted hydrocarbons and undesired by-products. In known processes, this cracked gas is first subjected to processing before it is fractionated for recovery

different hydrocarbons or hydrocarbon fractions is fed. Details are described in the cited article, in particular in Section 5.3.2.1, "Front-End Section" and 5.3.2.2., "Hydrocarbon Fractionation Section".

A corresponding processing includes in particular what is known as a

Sour gas removal, in which components such as carbon dioxide, hydrogen sulfide and mercaptans are separated from the cracked gas. The cracked gas is typically compressed before and after an appropriate treatment. For example, the cracked gas can be taken from a so-called raw gas compressor at an intermediate pressure level, subjected to the acid gas removal, and then in the

Raw gas compressor can be further compressed.

The acid gas removal can in particular include a so-called lye washing using sodium hydroxide solution. Especially at high concentrations

Sulfur compounds, the caustic wash can also be combined with an amine wash, for example using ethanolamine. The waste liquor obtained in the caustic washing, which has sulfide and carbonate in a content of a few percent, is typically oxidized in a waste liquor treatment and, if necessary, neutralized before it can be subjected to biological waste water treatment. The oxidation serves to remove toxic components and to reduce the biological oxygen demand. The waste liquor oxidation is typically carried out in the form of a wet chemical oxidation of the sulfide with oxygen in solution.

Several different methods are known from the prior art

Known wet oxidation of spent waste liquors. For example, see the article by CB Maugans and C. Alice, "Wet Air Oxidation: A Review of Commercial Sub-critical Hydrothermal Treatment", IT3Ό2 Conference, May 13-17, 2002, New Orleans, Louisiana, or US Pat. No. 5,082,571 A referenced.

The spent liquor can be used in such processes to the desired

Reaction pressure brought and heated in countercurrent with the oxidized waste liquor. The heated, used waste liquor can then be fed into an oxidation reactor with the addition of oxygen and oxidized. The oxygen required for the reaction is added either in the form of air or as pure oxygen. An additional, in other process variants also the exclusive, heating of the spent waste liquor can be carried out by introducing hot steam into the oxidation reactor.

After a typical dwell time of around one hour (depending on the selected temperature and pressure), the oxidized waste liquor is mixed with the

associated exhaust gas is cooled via a heat exchanger while heating the spent waste liquor. After a pressure check, a subsequent

Separation tank separates the exhaust gas from the liquid. The liquid oxidized waste liquor can then be fed into a process for biological waste water treatment with optional adjustment of the pH value (neutralization).

Further processes and process variants are from DE 10 2006 030 855 A1, US 4,350,599 A and the article by CE Ellis, "Wet Air Oxidation of Refinery Spent Caustic", Environmental Progress, Volume 17, No. 1, 1998, pages 28 30 described.

The oxidation of the sulfur-containing compounds in the spent waste liquor normally takes place in two different steps. The oxidation of sulfides produces sulfite, sulfate and thiosulfate in parallel. While sulfite is oxidized further to sulfate very quickly, the further reaction of thiosulfate is comparatively slow. The main reactions are as follows:

The state of the art in the oxidation of waste liquor is an operating pressure of 6 to 40 bar and an operating temperature of over 200 O, for example up to 210 O. The higher the temperature selected in the reactor, the higher the pressure must be set, since the steam pressure increases significantly the temperature rises. The residence time in the reactor required for substantial conversion drops from around 12 hours at 6 bar to 10% of the stated residence time at 30 bar.

According to the state of the art, the waste liquor is fed into the oxidation reactor. An oxygen carrier, usually air, is placed anywhere, usually in front of the

actual reactor, mixed with the lye. The waste liquor or the waste liquor-oxygen carrier mixture can be preheated in a heat exchanger.

According to the prior art, the waste liquor can thus be preheated in the

Oxidation reactor are abandoned. However, this is not absolutely necessary. Further heating (or the only heating) often takes place by adding steam, which can either be added to the incoming waste liquor or directly into the reactor, and generally also through the enthalpy of reaction or exothermicity of the oxidation reactions. As mentioned, the waste liquor to the reactor can also be preheated against the product from the reactor in appropriate processes.

Since the pressure of the gas phase is made up of the vapor pressure and the pressure of the

Oxidation air is added and the pressure of the incoming steam must be at least as high as the reactor pressure, is the main reason for the steam addition mentioned

overheated steam in question. This partially condenses and in this way supplies the additional heat.

An oxidation reactor used for the oxidation of waste liquor is constructed according to the prior art in such a way that a directed flow is formed in the reactor and thereby a greater reaction rate and a higher conversion are possible. For this purpose, fixtures in the form of perforated floors can be used.

Processes of the type explained above are known, for example, from DE 10 2010 049 445 A1, in which a pressure of more than 60 bar is used in a corresponding reaction reactor, and from DE 10 2006 030 855 A1.

Reactors for the oxidation of waste caustic are made of high-quality materials such as nickel-based alloys or nickel due to the extreme stresses involved. However, such materials can also be attacked by high sulfide concentrations at elevated temperatures.

The aforementioned steam is added to the oxidation reactor typically via one or more nozzles or lance designs. The distribution of the steam should take place as evenly as possible over the area of ​​the reactor, since the

Oxidation reactor, as mentioned, typically flows through in one direction and cross-mixing is limited as a result. As explained below, a corresponding addition of steam cannot be controlled in conventional processes and systems, or only to a limited extent.

According to GB 1 475 452 A, sludge is made by heating with previously treated

Heated sludge and fed to a steamed oxidation chamber of a reactor, which is in the oxidation chamber and a

Heat concentration chamber is divided.

WO 201 1/002138 A1 discloses a method for treating caustic soda, comprising the neutralization of the caustic soda produced by an oil refining process using sulfuric acid, and the wet air oxidation of the neutralized caustic soda.

The object of the present invention is to provide a method for wet oxidation of a waste liquor which makes it possible to achieve optimum oxidation of the sulfur constituents of the waste liquor, in particular at an operating pressure of 20 to 40 bar and with a minimum residence time. At the same time, the process should have another

Be controllable operating range, in particular using very different amounts of steam. In the process, the peak operating temperature should be reduced in order to minimize the corrosive attack on the reactor material, which is primarily dependent on the temperature. Another object of the present invention is to provide a system that can be operated accordingly.

Disclosure of the invention

Against this background, the present invention proposes a method for

Treatment of a waste liquor of a caustic wash using a

Oxidation reactor and a corresponding system and a corresponding oxidation reactor with the features of the respective independent claims. Refinements are the subject of the dependent claims and the following description.

Advantages of the invention

The present invention is based on the knowledge that the problems explained above can be overcome in the manner indicated by using an oxidation reactor configured as explained in detail below.

The present invention proposes a method for treating a sulphide-containing waste liquor from a caustic wash, in which the waste liquor and

Oxygen or the waste liquor and an oxygen-containing gas mixture, for example air, fed to an oxidation reactor and subjected to wet oxidation in this. Steam is fed into the oxidation reactor.

The advantages explained above are achieved by using a corresponding method. Reference is made below to features and advantages of embodiments of methods according to the invention, relating to these plants or oxidation reactors according to the invention with corresponding steam feed devices in the same way. The features of methods and devices according to the invention as well as corresponding variants are therefore explained together.

According to the invention, an oxidation reactor with a number of chambers is used here, of which a first chamber has a larger volume than a second chamber. The waste liquor and the oxygen or the waste liquor and the oxygen-containing gas mixture are fed to the first chamber. Fluid flowing out of the first chamber is transferred into the second chamber. A steam quantity and / or a steam temperature of the steam fed into the oxidation reactor is regulated with a control device, and that in the oxidation reactor

In the context of the present invention, steam fed in is at least partially, in particular completely, fed into the first chamber and the second chamber.

The number of chambers used in the oxidation reactor used according to the invention is in principle not limited. However, at least four chambers are typically provided, including the aforementioned first and second chambers. The chambers are preferably arranged in series in a corresponding oxidation reactor. A corresponding oxidation reactor is typically arranged upright, with the chambers mentioned lying one above the other. The oxidation reactor is typically flowed through with fluid from bottom to top, the mentioned first chamber being the lowermost chamber and the mentioned second chamber being the chamber arranged above the lowermost chamber following the lowermost chamber.

The named chambers are typically separated from one another by means of suitable separating devices, for example by sieve trays or by trays with nozzle valves to reduce the backflow and thus the backmixing. The steam is fed in in the manner explained below, ie in particular using specifically designed

Steam injection devices that allow the amount of steam fed in to be varied over a wide range.

As mentioned, the invention comprises that the steam fed into the oxidation reactor is at least partially fed into the first chamber and into the second chamber. In other words, the steam is supplied advantageously in parallel into the first and second chambers. A “parallel” feed does not necessarily include the feed of the same, but in each case certain, amounts of steam into the first and second chambers.

In other words, the present invention comprises the use of an entering chamber, the mentioned first chamber, and one in

Direction of flow downstream of the second chamber in a corresponding reactor. The chamber close to the inlet, that is to say the first chamber, and the subsequent chamber, that is to say the second chamber, are provided with a steam lance or some other feed device for steam.

The (first) chamber near the entrance is enlarged in the context of the present invention compared to the (second) chamber following it, and in particular compared to all other chambers of the oxidation reactor, whereby comparatively high conversions can be achieved in this chamber. The volume of the first chamber is in particular 1.1 times, 1, 5 times, 2 times, 3 times or more than 3 times the volume of the second chamber. In this way, the use of the oxidation reactor designed according to the invention can prevent the occurrence of high educt concentrations near the inlet. In other words, a concentration of the sulfide which is introduced into the oxidation reactor via the waste liquor is reduced in the large first chamber near the inlet. In other words, a dilution in the first chamber. The lower sulfide concentration in this chamber has the advantage over the high concentration in the waste liquor that is fed in that the corrosive attack on the reactor material is lower. In particular in connection with the aforementioned regulation of the amount of steam and / or steam temperature of the steam fed into the oxidation reactor, this leads to a reduction in the corrosive attack on the

Reactor material.

In the context of the present invention, the oxidation reactor is advantageously supplied with saturated steam or steam superheated by at most 5 to 10 0. The

The steam temperature of the steam fed into the oxidation reactor is advantageously set by mixing water into the heated steam. In other words, within the scope of the present invention, a device is advantageously used which has superheated steam on the one hand and water on the other

are fed. In particular, a so-called desuperheater or

Desuperheater and a subsequent mixer can be used. By metering in the superheated steam to the desuperheater on the one hand and the water to the desuperheater on the other hand, a mixed temperature can be obtained which lies in the aforementioned range. At the same time, by adjusting the amount of saturated steam or superheated steam and water within the scope of the invention, which is done on the basis of an adjustment by means of the aforementioned control device, the resulting amount of steam can be adjusted.

In the context of the present invention, the regulation is advantageously carried out in such a way that the amount of steam and / or the steam temperature of the steam fed into the oxidation reactor is based on a temperature detected in the first chamber and / or the second chamber and based on a detected temperature from the reactor outflowing fluids is regulated. In other words, the temperature control therefore advantageously includes within the scope of the invention that the temperature of the chambers of the oxidation reactor each equipped with steam feed devices is carried out. The quantities of steam supplied are regulated on this basis. At the same time, an outlet temperature from the oxidation reactor is set or recorded.

Advantageously, in the context of the present invention, there is one

Control cascade is used, which includes that the temperature of the lowest chamber, that is, the mentioned first chamber, is set to a setpoint. At the same time, a maximum temperature is specified which cannot or must not be exceeded in this first chamber. The setpoint used for the temperature in the first chamber is specified within the framework of the regulation proposed according to the invention on the basis of the outlet temperature, that is to say on the basis of the detected temperature of the fluid flowing out of the reactor. In this way, in the context of the present invention, the temperature at the top of a corresponding oxidation reactor can be compared with the temperatures in the said chambers. The measured temperature in the chambers limits the amount of steam fed into these chambers.

By using the solution proposed according to the invention, a broad operating range from ideally 0 to 100% load, in practice typically from 5 to 100% load, can be made possible. The "load" corresponds in particular to an amount of steam. By using the control system used according to the invention, it is no longer possible to limit the operation by excessively high process temperatures.

In other words, the regulation proposed according to the invention comprises specifying a temperature setpoint and a maximum temperature in the first chamber and / or the second chamber. Due to the requirement to lower the temperature in the first chamber, that is to say the lowest chamber, with the highest concentration of sulfide, the temperature in the second chamber would possibly drop to a lower value than desired. The steam is therefore also fed into the second chamber. In this way, this can be specifically heated and the

Reaction conditions in this second chamber can advantageously be set.

As mentioned, the steam feed is therefore advantageously distributed over the two chambers or the steam feed devices provided there. The

Steam supply to both chambers is advantageously regulated separately. In the context of the regulation used according to the invention, the first chamber and the second chamber are each advantageously provided with an independent

Temperature sensor equipped and the regulation in each case in one another

independent control loops. The amount of steam that is fed into the lower chamber, that is to say the first chamber, is advantageously regulated to the temperature of the temperature element in the lowest, that is to say the first chamber. The control in the second chamber is cascaded, with the temperature at

Reactor outlet, is taken into account. Advantageously, within the scope of the present invention, the respective desired value is therefore predefined on the basis of the temperature of the fluid flowing out of the reactor.

In the context of the present invention, the volume of the first chamber is advantageously greater than an average volume of all of the chambers

Oxidation reactor, the factors explained above in particular apply.

Alternatively or additionally, the size of the first chamber can also be defined in relation to the total volume of the reactor. The volume of the first chamber is advantageously at least one third and at most two thirds of the total volume of all chambers. In other words, as already explained,

the chamber near the inlet is enlarged, while the other chambers are smaller than the first chamber. The smaller chambers, which are arranged downstream of the second chamber in particular, have the task of reducing the residence time distribution in order to optimize the conversion in the oxidation reactor as a whole.

As mentioned, within the scope of the present invention, the amount of steam of the steam fed into the oxidation reactor can advantageously be regulated in a range from 5 to 100%. This means that a steam quantity of the steam fed in at a first point in time can correspond to 5% to 100% of the steam quantity fed in at a second point in time, or a corresponding setpoint is specified by means of the control.

In the context of the present invention, the steam is advantageously at least partially introduced into the oxidation reactor by means of a steam feed device, which has one or more cylindrical sections each with a central axis and a wall, the central axis being or being perpendicular, and several groups of in the wall Openings are formed, each of the groups comprises a plurality of the openings, and the plurality of openings of each of the groups are arranged in one or more planes that are each oriented perpendicular to the central axis. Within the scope of the present invention, the first and the second chamber can in particular each be provided with a corresponding steam feed device. Several cylindrical sections can be provided in particular in larger reactors. For the sake of clarity, “a” cylindrical section is used below, but the explanations also relate to the case in which several cylindrical sections are provided.

Due to the construction of steam lances used in conventional processes, minimizing the amount of steam is difficult if not impossible. In the optimal case, the smallest amount of steam fed in can be a minimum of 40%, in the real case a minimum of 60% of the normal load, but not less. This is due to the fact that, due to an uneven flow to all lance holes, steam hits through

For example, local condensation and incorrect distribution of the steam are to be expected. The aforementioned steam feed via the one just mentioned

In contrast, the steam feed device enables the amount of steam fed in to be controlled particularly well.

In the context of the present invention, in contrast to a horizontal pipeline provided in some known way with one or more rows of holes, steam is advantageously introduced into the reactor exclusively via the mentioned cylindrical section of one or more corresponding steam feed devices and thus into the waste liquor or into a two-phase mixture introduced from waste liquor and air. The cylindrical section can be designed as a "pin" which, in particular in the middle, is arranged vertically in a corresponding reactor. A corresponding oxidation reactor is typically at least partially cylindrical for its part.

Because the cylindrical section is arranged vertically and in this several groups of openings are provided, which are arranged in several planes one above the other, condensate can collect in the cylindrical section due to condensation of the steam, which has a condensate level corresponding to the pressure conditions in the cylindrical Section can train. In other words, in the method according to the invention, steam is in the

Steam feed device or brought to condensation in its cylindrical section, with a condensate level being formed in the cylindrical section which depends in particular on the pressure of the steam fed in.

In the case of small steam volumes, the cylindrical section fills comparatively heavily with condensate and the steam only flows through those openings which are formed in planes arranged further above. In this way it can be ensured that the openings through which the flow passes are each optimally exposed to steam and that optimal flow conditions are established. In contrast, in

conventional arrangements always acted upon all openings with steam, but the individual openings viewed individually but flowed through less. A method proposed according to the invention therefore results in a uniform distribution of the steam with a low tendency towards steam hammer and pumping. With a higher load, ie with higher steam volumes, and thus a higher pressure in the cylindrical section, the cylindrical section is increasingly emptied of condensate and further openings, which are arranged in lower levels, are flowed through with steam until full load is reached.

If in the context of the present application it is mentioned that each of the groups comprises several of the openings and the several openings of each of the groups are arranged in one or more planes, this is understood to mean that each different groups can each have openings that are above and below a reference plane can be arranged. In this way, even when a corresponding reactor is slightly inclined or when there is turbulence in the condensate level in the cylindrical section, in particular due to the

Steam feed, a sufficient flow must be ensured. In the simplest case, ie when the several openings of each of the groups are arranged in one plane, several rows of holes are arranged one above the other, the openings of different rows of holes advantageously each standing on gaps so that particularly good vapor mixing can be ensured.

In each of the planes, the respective openings are advantageously arranged equidistantly distributed around a circumference defined by a line of intersection of the respective plane with the wall. In other words, each radial lines which emanate from the central axis in the corresponding plane and run through the respective openings enclose identical angles. In this way, especially when the oxidation reactor is cylindrical, a uniform

Mixing must be ensured.

Advantageously, in the steam injection device that is used in a corresponding method, the openings of each of the groups are arranged in a plurality of planes and a maximum distance of the planes in which the openings of one of the groups are located is less than a minimum distance of the planes in which the openings are located two different groups. As already mentioned, the opening of each of the groups does not have to lie in exactly one plane, but can also be arranged in different planes, which, however, are closer to one another than the planes of two different groups.

Advantageously, two, three, four or more of the openings are arranged in each of the planes and, as mentioned, are distributed equidistantly along the wall around the circumference of the cylindrical section. This results in intermediate angles between the openings of 180 ° or 120 °. 90 °. The number of openings per level can also be different. In particular, the number of openings can be minimized in a top level so that the lowest possible underload operation can be guaranteed.

Advantageously, the cylindrical portion of the steam feed device has a first end and a second end and is at the first end by a

Closing surface closed. The first end points downwards and ensures that the condensate can collect in the cylindrical section. In particular, at least one further opening can be formed in the closing surface, which ensures that condensate can drain out of the cylindrical section. Several openings can also be arranged in the end surface, the size and number of which can depend in particular on the amount of steam to be processed or fed in.

The cylindrical section is advantageously connected at the second end to a steam feed line and / or holder, which extends from the second end of the cylindrical section to convert the oxidation reactor used. If a steam feed line is provided, this can in particular be cylindrical and have the same or different diameter as the cylindrical section of the steam feed device. In order to ensure simple production, the diameters are advantageously identical.

The openings in the cylindrical section are advantageously of this type

arranged that steam flows out of this in each case in an outflow direction which is different from a direction in which the steam supply line and / or the mounts extend in a plan view from the direction of the central axis. In other words, the openings are each arranged in such a way that steam flowing out through them is advantageously not directed at the supply line and / or holder in order to ensure the most free outflow possible.

In the method according to the invention, the waste liquor and the oxygen or the oxygen-containing gas mixture are advantageously premixed before they

Oxidation reactor are fed. The waste liquor and the oxygen or that

oxygen-containing gas mixtures are advantageously at

Ambient temperature fed to the oxidation reactor and only heated in this. In this way, a temperature can be precisely set and regulated, in particular in the first chamber, in order to achieve the advantages of reduced corrosive attack on the reactor explained above.

In the context of the present invention, the oxidation reactor as a whole is advantageously operated at a pressure level of from 20 to 50 bar, in particular from 30 to 40 bar and at a temperature level from 150 to 220 °, in particular from 185 to 210 °. The inventive vorgese Hene configuration of

Oxidation reactor is thereby reduced corrosive attacks.

The present invention also extends to an installation for the treatment of a sulphide-containing waste liquor from a caustic wash, for the features of which reference is expressly made to the respective independent patent claim. The same also applies to the oxidation reactor proposed according to the invention. Advantageously, a system of this type or a corresponding oxidation reactor is set up to carry out a method, as has been explained above in different configurations, and a corresponding system has corresponding features for this purpose

trained agents. Reference is therefore expressly made to the above explanations for corresponding features and advantages.

The invention is explained in more detail below with reference to the accompanying drawings which illustrate aspects of the present invention.

Brief description of the drawings

FIG. 1 shows a plant for treating a waste liquor according to an embodiment of the invention in a simplified representation.

Figure 2 illustrates an oxidation reactor for use in a plant according to an embodiment of the invention in a schematic partial representation.

FIG. 3A illustrates a steam feed device for use in a plant according to an embodiment of the invention in a first embodiment.

FIG. 3B illustrates a steam feed device for use in a plant according to one embodiment of the present invention in a second

Design.

Detailed description of the drawings

In the figures, elements that correspond to one another functionally or structurally are indicated with identical reference symbols. For the sake of clarity, these are not explained repeatedly.

In FIG. 1, a system for treating a waste liquor according to a particularly preferred embodiment of the invention is schematically illustrated and designated as a whole by 100.

A central component of the system 100 illustrated in FIG. 1 is a

Oxidation reactor 10. This has a total of nine in the example shown

Reactor chambers 1 1 to 19, but at least four reactor chambers.

A chamber 11 located at the bottom in the example shown, and optionally the subsequent chamber 12, are each provided with a steam feeder 21 and 22, for example a steam lance or a steam chamber protruding into the respective chamber 11, 12. The chamber 11 close to the entrance is enlarged compared to the other chambers 12 to 19, with the aim of achieving relatively high conversions in this chamber and in this way the occurrence of higher ones near the entrance

To prevent educt concentrations. The enlarged chamber 11 is larger than the mean chamber volume and typically comprises more than one third of the total reactor volume and typically less than two thirds thereof. The smaller chambers 12 to 19 above have the task of reducing the residence time distribution in order to optimize sales.

The steam feeders 21, 22 are part of a steam system 20 which is based on a temperature sensor control TIC, to which several temperature sensors TI, which are arranged on the chambers 1 1 and 12 and an outlet of the oxidation reactor 10, are connected. The temperature sensor control TIC regulates two valves 23, 24 which are arranged upstream of a desuperheater 25 and by means of which an inflow of superheated steam 1 or boiler feed water 2 to the desuperheater 25 is set. Fluid 3 flowing out of Desuperheater 25 is mixed in a mixer 26 and then distributed to chambers 11, 12 and steam feeders 21, 22 via valves 27 and 28.

The large chamber 21 close to the inlet leads to a lower concentration of the sulfide. The lower sulphide concentration in this chamber 21 compared to the high inlet concentration has the advantage that the corrosive attack on the

Reactor material together with an operating temperature regulated by means of the steam system 20 fails.

The temperature control by means of the steam system 20 is carried out by the

Temperature measurement of each equipped with steam feeders 21, 22

Chambers 1 1, 12 and controls the amount (s) of supplied steam. At the same time, an outlet temperature is set. Therefore a control cascade is used. The temperature at the top of the oxidation reactor 10 is compared with the temperatures in the chambers 1 1, 12 with the steam feeders 21, 22 and the measured temperature in the chambers 1 1, 12 with the steam feeders 21, 22 limits the amount of steam supplied. By means of the temperature sensor control, the temperature of the lowest chamber 11 is set to a target value, a maximum temperature not being allowed to be exceeded. The setpoint is in turn set by a second controller that controls the outlet temperature at the head of the

Oxidation reactor 10 controls.

An insert 4, which is typically two-phase and is formed from liquor 5, which is taken from a tank 30, and from air 6, is fed to the oxidation reactor 10. The insert 4 is the oxidation reactor 10 in the example shown

Ambient temperature and supplied at 20 to 40 bar. A typically three-phase component mixture 4 is withdrawn from the oxidation reactor 10. A flow of this component mixture out of the oxidation reactor 10 is set by means of a valve 40, which is also operated with temperature control.

In FIG. 2, a section of an oxidation reactor for use in a plant according to an embodiment of the present invention is illustrated in a highly simplified schematic and denoted overall, as in FIG. 1, with 10. The oxidation reactor 10 has a wall 210 which encloses an interior 220 of the oxidation reactor 10. A waste liquor or a waste liquor-air mixture can be received in the interior space 220 and, for example, can be guided essentially in the direction shown here by 230 arrows.

As mentioned, in particular the oxidizing air and the waste liquor before the

Feed into the oxidation reactor 10 are heated. Additional heating can take place by means of a steam stream 240, which, as illustrated here, is introduced via a steam feed device 21 into the oxidation reactor 100 or into the waste liquor accommodated therein. The steam feed device 22, which is shown in Figure 1, can be designed identically.

The steam feed device 10 comprises a cylindrical section 21 1, which has a central axis 212, which is in particular a central axis of the

Oxidation reactor 10 may correspond overall. The cylindrical section 21 1 comprises a wall 213. The central axis 212 is aligned vertically. In the wall 213 several openings 214 are arranged, which only partially

Reference numerals are provided. The openings 214 are arranged in a plurality of groups, each of the groups comprising a plurality of the openings 214 and the plurality of openings of each of the groups being arranged in one or more planes, which have been illustrated here by dashed lines and are denoted by 215.

The planes 215 are each aligned perpendicular to the central axis 212. In other words, the central axis 212 intersects the planes 215 perpendicularly. In this way, within the scope of the present invention, several rows of openings 214 or rows of holes are formed, which allow condensate to accumulate in the cylindrical section 21 1 and only through the openings 14 that remain free steam into the interior 220 of the oxidation reactor 10 or is introduced into the waste liquor present there. In this way, a corresponding oxidation reactor 10 can be operated in an optimized manner, as explained several times above.

As explained, the openings 214 are provided in the different planes 215 in the same or different numbers, in particular in a plane 215 shown here above only a smaller number of openings can be provided in order to enable a minimum load. Regarding the distances IO and 11 of the individual planes 214 from one another and with regard to the cylindrical section 21 1, express reference is made to the above explanations.

At a lower end or first end, the cylindrical section 21 1 is closed by an end surface 216 in which at least one further opening 217 is arranged. At an opposite second end of the cylindrical

Section 21 1, this is connected to a steam supply line 218, which can have the same or different diameter to the cylindrical section. The row of openings 214 located closest to the steam feed line 218 advantageously has the smallest number of openings 214. The formation and orientation of the respective openings 214 have been explained in detail above. The steam supply line 218 is closed at one end by a closure or it has one or more further openings 220.

In FIG. 3A, the steam feed device 21, which is already illustrated in FIG. 2 as part of the oxidation reactor 100, is shown in a different perspective, a top view along the axis 212 according to FIG. 2 being shown here from below. As shown here, the openings 214 are arranged in the cylindrical section 21 1 in such a way that an outflow direction for steam defined by them deviates from a central axis of the steam feed line 218.

If, as shown in the example shown in FIG. 3A, three openings are illustrated in one plane, an intermediate angle between these is 120 ° and these are at the illustrated angle of 60 ° relative to a perpendicular to

Central axis of the supply line 218 inclined.

In Figure 3B, the corresponding relationships, already shown in Figure 3A, are shown for the case that four openings 214 in a plane 215 one

corresponding cylindrical portion 21 1 are provided.

Claims

1. A method for treating a sulphide-containing waste liquor from a caustic wash, in which the waste liquor and oxygen or an oxygen-containing gas mixture are fed to an oxidation reactor (10) and are subjected to wet oxidation in this, with steam being fed into the oxidation reactor (10), characterized in that that an oxidation reactor (10) with a number of chambers (1 1-19) is used, of which a first chamber (1 1) has a larger volume than a second chamber (12), the waste liquor and the oxygen or the oxygen-containing Gas mixture is fed to the first chamber (11), fluid flowing out of the first chamber (11) is transferred into the second chamber (12),a steam quantity and / or steam temperature of the steam fed into the oxidation reactor (10) is regulated with a control device (TIC), and the steam fed into the oxidation reactor (10) at least partially into the first chamber (11) and into the second chamber ( 12) is fed in.

2. The method according to claim 1, wherein the steam is fed as saturated steam or as superheated by at most 5 to 10 C steam in the Oxidationsreakto r (10), the steam temperature of the steam fed into the oxidation reactor (10) by mixing water in superheated Steam is set.

3. The method according to claim 2, wherein an amount of the saturated steam and / or the superheated steam and / or the water is adjusted by means of the control device (TIC).

4. The method according to any one of the preceding claims, wherein the amount of steam and / or steam temperature of the steam fed into the oxidation reactor (10) based on a temperature detected in the first chamber (11) and / or the second chamber (12) and on Based on a detected temperature of a fluid flowing out of the reactor (10) is regulated.

5. The method of claim 4, wherein the regulation comprises, a

Preset temperature setpoint and a maximum temperature in the first chamber (1 1) and / or the second chamber (12).

6. The method according to claim 5, wherein the temperature setpoint is predetermined based on the temperature of the fluid flowing out of the reactor (10).

7. The method according to any one of the preceding claims, wherein the volume of the first chamber (13) is greater than an average volume of all chambers (1 1-19) of the oxidation reactor (10) and / or at least one third and at most two thirds of a total volume all chambers (1 1) includes.

8. The method according to any one of the preceding claims, wherein the amount of steam of the steam fed into the oxidation reactor (10) is regulated in a range from 5 to 100%.

9. The method according to any one of the preceding claims, wherein the steam

is introduced into the oxidation reactor (10) at least partially by means of at least one steam feed device (21, 22), which has a cylindrical section (21 1) with a central axis (212) and a wall (213), the

Central axis (212) is or is vertically aligned, in the wall several groups of openings (214) are formed, each of the groups comprises several of the openings (214), and the several openings (214) of each of the groups in one or more planes ( 215) are arranged, each of which is or are oriented perpendicular to the central axis (212).

10. The method according to any one of the preceding claims, in which the waste liquor and the oxygen or the oxygen-containing gas mixture are premixed before they are fed to the oxidation reactor (10), and in which the waste liquor and the oxygen or the oxygen-containing gas mixture at ambient temperature to the oxidation reactor ( 10) can be supplied.

1 1. The method according to any one of the preceding claims, wherein the

Oxidation reactor (10) is operated at a pressure level of 20 to 50 bar and at a temperature level of 150 to 220 O.

12. Plant (100) for treating a sulphide-containing waste liquor from a caustic wash, with means which are set up for the waste liquor and oxygen or a

Feeding an oxygen-containing gas mixture to an oxidation reactor (10) and subjecting it to a wet oxidation in this, wherein means are provided which are set up to feed steam into the oxidation reactor (10), characterized in that the oxidation reactor (10) has a number of chambers (1 1-19), of which a first chamber (1 1) has a larger volume than a second chamber (12), means being provided to supply the waste liquor and the oxygen or the oxygen-containing gas mixture to the first chamber (1 1), to transfer fluid flowing out of the first chamber (11) into the second chamber (12), a steam quantity and / or steam temperature of the steam fed into the oxidation reactor (10) with a

To regulate control device (TIC), and to feed the steam fed into the oxidation reactor (10) at least partially into the first chamber (11) and into the second chamber (12).

13. Oxidation reactor (10) for use in a plant (100) for treatment

a sulphide-containing waste liquor from a caustic wash, the system (100) having means which are set up to feed the waste liquor and oxygen or an oxygen-containing gas mixture to the oxidation reactor (10) and to subject it to wet oxidation in it, the oxidation reactor (10)

Has means which are set up to feed steam into the oxidation reactor (10), characterized in that the oxidation reactor (10) has a number of chambers (1 1-19), of which a first chamber (1 1) has a larger volume as a second chamber (12), wherein means

are provided to supply the waste liquor and the oxygen or the oxygen-containing gas mixture to the first chamber (1 1), to transfer fluid flowing out of the first chamber (1 1) into the second chamber (12), a steam quantity and / or steam temperature of the Oxidation reactor (10) fed steam with a control device (TIC) to regulate, and in the

Oxidation reactor (10) to feed steam at least partially into the first chamber (11) and into the second chamber (12).