EP1271053A2 - Process to incinerate wastes with high halogen content in a way generating low emissions and low corrosion - Google Patents

Abstract

Sulfur, or a suitable sulfur carrier, is dosed under control into a furnace chamber, as a function of the total proportion of halogen and the halogen type. An Independent claim is included for the corresponding waste incineration plant. Preferred features: Sulfur quantity dosed under control is proportional to the current total fraction of Cl, Br or I in the waste. Sulfur quantity dosed is controlled in accordance with an operationally-determined sulfur dosing graph. This achieves the necessary SO2 residual concentration in the raw gas following the boiler, before quenching, corresponding with the Cl-, Br- or I- rich waste. The determination is carried out for at least one predominant fraction of Cl, Br or I in the waste. The minimum necessary SO2 content in the boiler raw gas is found, under steady state operation, to reduce the quantity of free Cl, Br or I detected in the purified gas following the scrubber, to zero or a set limit. The current total halogen fraction on the flue gas side is determined as halogenide content in effluent water from the acid flue gas scrubber, i.e. as the product of halogenide concentration and volumetric flow of effluent, determined continuously. In another alternative, it is determined from measurements of halogen and hydrogen halide species in the boiler flue gas after the boiler and before quench, and the dry volumetric flow rate of flue gas. As an alternative to the latter, a magnitude proportional to the volumetric flow rate of the flue gas is taken, e.g. the rate of steam generation at the boiler, is determined continuously. Sulfur content is raised momentarily, preferably by 10% to 50%, should free halogen be detected in purified gas from the scrubber but ahead of any SCR (selective catalytic reduction) catalyst bed. Similar action is taken on detection of excessive halogen in effluent water from the acid scrubber. Sulfur is added as solid, liquid, or as waste sulfuric acid. Solid sulfur is dosed as pellets by pneumatic conveying into the primary combustion zone (3). Waste sulfuric acid is dosed to the primary or secondary furnace zone (4) using controlled metering pumps and nozzles. Where halogen content in the flue gas cycles as a result of dosing halogen-rich waste packages, dosing of sulfur is controlled in sympathy, in respect of quantity, time and duration. Hypo-halogenide reduction in the alkali scrubber is effected through bisulfide process sinters formed from the residual SO2 of the boiler raw gas and/or by an externally-supplied reductant such as thiosulfate. Sympathetic control of sulfur dosing is a function of automatically-read bar codes on the packs, thus giving information on calorific value, halogen type and halogen quantity in the pack.

Description

The invention relates to the low-corrosive and low-emission co-incineration of highly halogenated waste, preferably liquid waste, in a waste incineration plant. Undesirable free halogens such as free chlorine Cl ₂ , free bromine Br ₂ and / or free iodine I ₂ form partly already in the furnace and then - to a greater extent - with the beginning of flue gas cooling in the subsequent boiler. The temperature-dependent, kinetically limited replication of free halogens from the corresponding hydrogen halides follows the so-called Deacon reaction, which, fortunately, is strongly inhibited. Due to the regulated addition of sulfur to the combustion chamber of the waste incineration plant and the SO ₂ formed as a result of combustion, it is possible to largely suppress these free halogens in the boiler, ie on the way to the end of the flue gas.

A waste incinerator is described, for example, in H.W. Fabian et al. [1]. Typical waste incinerators include a primary furnace (e.g. Rotary kiln), a secondary combustion chamber (secondary combustion chamber), a waste heat boiler, sometimes also an electrostatic or filtering dust collector, a Flue gas scrubbing with e.g. one - stage or multi - stage acid laundry (quenches and e.g. acid rotary atomizer scrubber) and alkaline wash (e.g., alkaline Rotary atomizer scrubber), optionally also with a mist eliminator and e.g. a condensation electrostatic precipitator.

When incinerating waste containing halogens, hydrogen halides such as HCl and, to a lesser extent, free halogens and traces of initially unbound halogen radicals and atoms are formed in the furnace by hydrolysis. With the flue gas cooling, the latter recombine to free halogens. In addition, especially in the presence of metal oxide-rich fly ash as catalysts of the Deacon reaction (4 HX + O ₂ <---> 2 X ₂ + 2 H ₂ O with X = Cl, Br or I) - from the hydrogen halides more free halogens are formed like chlorine Cl ₂ . The extent of this replication of free halogens according to the catalyzed Deacon reaction is dependent on the type and amount of Kesselflugstäube

• Im Gegensatz zu den Halogenwasserstoffen sind freie Halogene im sauren Wäscherbereich unlöslich und können erst durch Chemisorption mit z.B. Natronlauge (NaOH) in der alkalischen Wäsche als Natriumhalogenid und - zu gleichen Teilen - als Natriumhypohalogenid ausgewaschen werden.
• Die Hypohalogenid-Konzentration im Wasser der alkalischen Wäsche muss - mittels eines ausreichenden Angebots an Reduktionsmitteln - niedrig gehalten werden, d.h. durch z.B. Hydrogensulfid oder Thiosulfat zum stabilen Natriumhalogenid reduziert werden, um reingasseitig Emissionen freier Halogene zu vermeiden. Bei unzureichendem Reduktionsmittelangebot besteht die Gefahr, dass gesetzlich vorgeschriebene Grenzwerte im Reingas nach Rauchgaswäsche nicht eingehalten werden.
• Höhere Konzentrationen freier Halogene im Kesselrauchgas können Korrosionen im Kessel wie auch in der weiteren Anlage verursachen.
• Freie Halogene begünstigen die sogenannte Denovo-Synthese von Dioxinen und Furanen im mittleren und hinteren Kesselbereich wie gegebenenfalls auch in einem dem Kessel direkt nachgeschalteten elektrostatischen oder filternden Staubabscheider.

Free halogens are undesirable for many reasons.

• In contrast to the hydrogen halides, free halogens are insoluble in the acid scrubbing area and can only be washed out by chemisorption with, for example, sodium hydroxide solution (NaOH) in the alkaline wash as sodium halide and - in equal parts - as sodium hypohalide.
• The hypohalide concentration in the water of the alkaline wash must be kept low by means of a sufficient supply of reducing agents, ie reduced by, for example, hydrogen sulphide or thiosulphate to the stable sodium halide in order to avoid emissions of free halogens on the clean gas side. If there is insufficient supply of reducing agents, there is a risk that legally prescribed limit values in the clean gas will not be complied with after flue gas scrubbing.
• Higher concentrations of free halogens in the boiler flue gas can cause corrosion in the boiler as well as in the rest of the system.
• Free halogens favor the so-called Denovo synthesis of dioxins and furans in the middle and rear boiler area as well as, where appropriate, in an electrostatic or filtering dust separator directly downstream of the boiler.

By suppression of free chlorine and / or other free halogens by means of SO ₂ , the above-described undesirable effects such as the formation of dioxins and furans [1] can be suppressed or at least severely restricted, cf. [2], [3], [4].

It is known that the free halogens still react in the boiler with SO ₂ . Free chlorine, for example, reacts with SO ₂ and water vapor to form SO ₃ back to the hydrogen chloride, cf. eg [1] for Cl ₂ suppression. Free bromine also reacts with SO ₂ , cf. [5]; However, this reaction between Br ₂ and SO ₂ probably does not lead directly to hydrogen bromide, but first in the boiler to SO ₂ Br ₂ (sulfuryl bromide), which is subsequently hydrolyzed in the acid wash to HBr and SO ₄ ^2- . In the combustion of highly halogenated waste is not known exactly what shares of the respective halogen charge in the boiler flue gas in the meantime as free halogens X ₂ (eg as Cl ₂ and / or Br ₂ ) are present; it is only known that, in the case of bromine and iodine, a much higher proportion of free halogens is tended to be reproduced than in the case of chlorine, according to the temperature dependence of the thermodynamic equilibria of the respective "Deacon reaction".

According to Fabian et al. [1] the ratio of sulfur and chlorine in the burned waste menu should be such as to give a "molar ratio of sulfur / chlorine>1". However, it was not known in detail how much "chlorine" (meaning free chlorine) is present in the meantime as a molar reference variable with varying chimney freights in the boiler flue gas. Corresponding uncertainty existed and persist to this day with the other free halogens such as in particular Br ₂ and I ₂ .

It is also known that the (in the strong acid scrub area almost insoluble and therefore not washable there) free halogens such as Cl ₂ and / or Br ₂ with the (in the strong acid scrub area also almost insoluble) residual SO ₂ from the boiler raw gas before quenches only at the subsequent common Chemisorption be solved in the alkaline scrubber and then stable as eg NaX are involved, namely by reducing the chemisorption in addition to NaX initially formed, unstable hypohalide NaOX to stable NaX, cf. [6].

Finally, it is also known that this reduction of NaOX to stable NaX can be achieved not only by the hydrogen sulfide which forms in-process from the residual SO ₂ chemisorbed in the alkaline scrubber, but also by a reducing agent fed externally into the alkaline scrubber, such as eg thiosulphate (Na ₂ S ₂ O ₃ .5H ₂ O), cf. [7].

The previously known from the prior art measures at waste incineration plants are for a reliable and at the same time cost-effective suppression and / or involvement in the combustion of highly halogenated Waste formed free halogens not sufficient. As a result of targeted Changes in the waste menu and operational fluctuations often occur varying total halogen loads. Nevertheless, suitable measures are missing for one The current total halogen freight always optimally adapted resource addition and consequently a cost-optimized suppression of free halogens, in particular at high total halogen loads.

The object of the invention is therefore to provide a method for corrosion and Low-emission co-incineration of highly halogenated waste in waste incineration plants with minimal use of resources and minimal waste accumulation to find.

The solution of the object according to the invention consists in a method and a Apparatus for low-corrosion and low-emission co-combustion of highly halogenated Liquid wastes in waste incineration plants with at least one combustion chamber, a waste heat boiler, a flue gas scrubber (e.g., consisting of a on or multi-stage acid laundry and alkaline laundry), whereby the firebox, in addition to other sulphurous waste, solid or liquid sulfur or corresponding sulfur carriers, e.g. Waste sulfuric acid are added metered. The regulation of the addition of sulfur or corresponding sulfur carriers takes place - essentially - proportionally to the current total halogen load (e.g. the chlorine and / or bromine total freight) in the flue gas.

The sulfur may be in the form of solid sulfur in the primary or secondary combustion chamber, Liquid sulfur or other sulfur carriers, e.g. Waste sulfuric acid, be added directly.

Solid sulfur is preferably added in pelleted or granulated form. This form of addition has the advantage that the pelleted or granulated solid sulfur (For example, so-called sulfur granules) can be handled safely and well dosed, better than e.g. powdery sulfur flower. The sulfur granules are preferred added pneumatic entry into the primary furnace. The entry of the Sulfur granules should with a controllable dosing and delivery unit such as Metering screw or vibrating trough done. Preferred is a variable speed Dosing screw with subsequent injector and pneumatic delivery line to the combustion chamber, preferably to the head of the rotary kiln ("blowing the sulfur granules"). Waste sulfuric acid is transferred by means of a controllable dosing pump Atomizing nozzles or corresponding nozzles in the primary or secondary Firebox added.

Other sulphurous wastes as well as the regulated metered-in solid or liquid sulfur or sulfur carriers burn in the primary and / or secondary furnace to form SO ₂ .

The addition of sulfur or other sulfur carriers in the furnace is according to the invention - starting from the current flue gas halogen total freight - to regulate so that a calculated target SO ₂ content in the flue gas before boiler or - alternatively - a corresponding target SO ₂ - Residual content in the boiler raw gas before quenching is continuously maintained.

The controlled addition of sulfur or sulfur carriers should sufficiently but not excessively increase the SO ₂ supply in the boiler flue gas. The required for the suppression of free halogens in the boiler as well as for hypochlorite reduction in the subsequent alkaline scrubbing SO ₂ demand increases with the halogen total freight, ie the necessary SO ₂ content in the flue gas before boiler (after afterburning) or the corresponding SO ₂ residual content in the boiler raw gas after boiler (before quenching) must be raised with the total halogen load. In this case, the proportion of free halogens in the total halogen load in the case of bromine or even iodine is considerably greater than in the case of chlorine and thus also the specific, ie related to the total flue gas total halogen demand for sulfur.

It was determined on the basis of "chlorine and sulfur balances" in operational tests that in the boiler flue gas of a typical waste incineration plant (operated with oxygen contents of eg 11 vol .-% tr. O ₂ and water vapor contents of eg 10 ... 30 vol .-% tr H ₂ O) from hydrogen chloride via the so-called chloro-Deacon reaction (4 HCl + O ₂ <---> 2 Cl ₂ + 2 H ₂ O) with progressive flue gas cooling about 4% of the total chlorine load as free chlorine Cl ₂ be reproduced. Of these 4% of replicated free chlorine, about 75% (corresponding to about 3% of the total chlorine load) is still in the boiler - via the Griffin reaction Cl ₂ + SO ₂ + H ₂ O ---> 2 HCl + SO ₃ - with SO ₂ and steam re-formed to HCl. With sufficient supply of sulfur so arrive about 99% of the chlorine in total as water-soluble HCl directly into the wastewater of acid laundry. Accordingly, only about 1% of the total chlorine content passes as free chlorine Cl ₂ into the waste water of the subsequent alkaline wash. There, the free chlorine Cl _{2 is} chemisorbed at the same time with the SO ₂ and - with sufficient residual SO ₂ -Angebot from the crude gas before quenching - reduced to sodium chloride.

From operating tests and corresponding balances for the case of bromine, it was found that the replicated fraction of free Br ₂ Br in the boiler flue gas of a Abfallverbrennungsan- location (operated with oxygen contents of, for example, 11 vol .-% tr. O ₂ and water vapor contents of eg 10 ... 30 Vol .-% tr. H ₂ O) is much larger than that of chlorine: The Br ₂ content was not only 4% of the total halogen load (see chlorine), but between 40% for smaller total bromine loads and 65% at very high bromine total loads.

Such balances in the case of bromine show that the free bromine is still> 90% suppressed with sufficient SO ₂ supply in the boiler, probably by the formation of sulfuryl bromide SO ₂ Br ₂ according to the reaction equation SO ₂ + Br ₂ <---> SO ₂ Br ₂ . In any case, our operating trials with smaller to very large total bromine loads always showed that - as was previously unknown - a reaction product is already formed in the boiler, probably at present. not yet directly detectable SO ₂ Br ₂ , which - proven - hydrolyzed in the acid scrubber to HBr and SO ₄ ^2- . In the case of sufficient SO ₂ supply in the flue gas, even in the case of bromine, about 99% of the total halogen charge is again present as bromide HBr in the waste water of the acid wash. Also in this case - as in the case of chlorine - only about 1% of the total halogen load as Br _{2 get} into the water of the alkaline wash, where it is chemisorbed and - with sufficient residual SO ₂ supply - reduced to stable NaBr.

The halide load of acid wastewater is thus a good measure of total halogen freight the boiler flue gas, at least in steady-state operation, because with constant admission, the total halogen load of the boiler flue gas both in the case of chlorine and in the case of bromine - with sufficient supply of sulfur - to about 99% with the halide load of the waste water of the acid wash identical.

By contrast, in the transient operating state, i. at fast freight changes, follows the halide load currently being discharged from the quench with the acid wastewater the current total halogen load of the boiler's flue gas only slowly, i.e. she appears late with the quenching wastewater, namely delayed in time the mean residence time of the wash water in the bottom of the acid wash (Order of magnitude: e.g., 45 minutes).

The halide concentration in the acid wastewater is e.g. from a conductivity measurement. As is known, the electrical conductivity of aqueous halide solutions strongly temperature-dependent; therefore, in the conductivity measurement for Temperature compensation integrated a temperature measurement. The associated halide freight in acidic wastewater results then by the multiplication of the halide concentration with the e.g. Measured by inductive flow meter Volume flow of acid wastewater.

As an alternative to the described indirect determination of total flue gas-halogen total freight as halide in acidic wastewater, the current total flue gas halogen freight could also directly, but comparatively expensive from the HX and X ₂ contents in the boiler raw gas and from the flue gas volume flow or a size proportional to the flue gas volume flow Steam output of the boiler can be determined; For this purpose, for example, with measuring instruments based on near-infrared spectrometry, the HX and X ₂ contents in the boiler raw gas would have to be measured before quenching.

In order to always adequately cover the sulfur demand - based on the current total halogen load - but not to provide unnecessarily much sulfur, a "primary control loop using a pre-determined sulfur metering ramp" is initially recommended for the sulfur mass flow to be metered. In this primary control loop, the continuously measured SO ₂ residual content in the boiler raw gas before quenches (after boiler) serves as a "controlled controlled variable", see below.

The suppression of intermediate free halogens takes place - as explained - in the boiler is not always complete, namely, for example, in the case of chlorine to only about 75%. The remaining approx. 25% free chlorine reaches the alkaline wash. If there are no other reducing agents are added from external side, so there is still always a certain residual SO ₂ content in the boiler raw gas before quenches (after boiler) to provide in-process enough in-soda sufficient bisulfide as a reducing agent.

The bisulfide formed in-process from the residual SO _{2 of} the boiler raw gas in the alkaline scrubber is known not to be stable to oxidation, ie it not only serves the desired reduction of hypochlorite (NaOCl) but also reacts with dissolved oxygen at the same time. The residual SO ₂ content required in the case of chlorine in the crude boiler gas before quenching is therefore considerably higher than the Cl ₂ residual charge chemisorbed in the alkaline scrubbing - stoichiometrically seen - would correspond. These findings lead to the desired value of the SO ₂ -Restgehalts in the dirty boiler gas upstream of the quench as a function of the current total chlorine cargo (kg Cl _tot / h), and - in respect of the cargo on the dry flue gas volumetric flow - from the corresponding Cl _tot concentration in the dirty boiler ( mg Cl _ges / Nm ³ _tr. ) on the notion of a plant-specific, sulfur-dosing ramp to be pre-determined for operation.

The sulfur dosing ramp can be determined operationally, for example in the case of chlorine, by carrying out a required "operating test at a preselected high total chlorine load" and starting it with an initially greatly increased supply of sulfur and, consequently, a greatly increased SO ₂ residual content in the boiler raw gas before quenches (after kettle). Consequently, in the alkaline scrubber initially there is also a considerable supply of bisulfide; On the other hand, there is no hypochlorite and correspondingly in the clean gas after alkaline scrubbing initially no free chlorine is detectable. Then the amount of sulfur is lowered gradually until free chlorine is detectable on the clean gas side. The preselected total chlorine load or the corresponding preselected Cl _ges concentration in the boiler raw gas (mg Cl _ges / Nm ³ _tr. ). On the one hand, and the SO ₂ residual content thus determined in the boiler raw gas on the other hand, in which free chlorine is noticeably detectable, form a point of the sulfur metering ramp.

In itself, this one point is sufficient to set a sulfur metering ramp as the relationship between the total chlorine load or the Cl _ges concentration in the flue gas on the one hand and the necessary minimum value of the continuously measured residual SO ₂ content in the boiler raw gas before quenching (after boiler) on the other hand because the sulfur metering ramp is the straight line through this one measuring point and the origin of the coordinates. Accordingly, the straight line thus determined indicates with sufficient accuracy for a wide range of chlorine contents which target SO ₂ residual content in the boiler raw gas must be maintained before quenching (according to the boiler) at different total chlorine loadings so that sufficient bisulfide is always present in the alkaline wash and the hypochlorite desired there Reduction takes place, so that hardly any free chlorine Cl _{2 is found} in the clean gas after the alkaline wash or only a minimal, below a predetermined limit lying Cl ₂ -Reingaskonzentration.

A corresponding plant-specific sulfur dosing ramp for dosing Sulfur can also be detected in the case of bromine or iodine.

As a result of the "SO ₂ consumption" in the boiler, the SO ₂ content in the flue gas upstream of the boiler (not operationally measured) must be significantly higher than the SO ₂ residual content in the boiler raw gas before quenching (according to the boiler). The determination of the difference, ie the halogen-related SO ₂ consumption in the boiler can be calculated: For example, the actual chlorine total load (or the corresponding chloride load in acid wastewater) with the plant-specific Cl ₂ conversion in the boiler (eg 3 % of the total chlorine load, namely 75% of a total of 4%), this value then divided by the molecular weight of Cl ₂ (70.914 kg Cl2 / kmol) and finally with the molecular weight of sulfur dioxide (64.06 kg S / kmol) to multiply. This calculated chlorine-related SO ₂ consumption in the boiler is now to be added to the SO ₂ residual requirement corresponding to the total chlorine load according to the sulfur metering ramp. Finally, the consumption of SO ₂ due to the known, unavoidable oxidative SO ₂ / SO ₃ conversion has to be considered; in waste incineration plants below 11 vol.% oxygen, this is about 8% of the total SO ₂ freight. Consequently, the previously determined SO ₂ content in the flue gas upstream of the boiler is still to be increased by the corresponding factor 1 + 0.08 / 0.92 = 1.09. The calculated so determined SO ₂ -SOLL content in the flue gas before boiler or the corresponding sulfur mass flow is sufficient both for the internal boiler partial suppression of free chlorine and for hypochlorite reduction in the circulating water of the alkaline wash.

Accordingly, in the case of bromine can be proceeded. In this case, the flue gas-side bromine total freight or the wastewater-side bromide freight is multiplied by the plant-specific proportion of intermediate free bromine determined for the case of bromine. According to our field trials, this proportion ranges from 40% at low total bromine loads to 65% at high total bromine loads, so it is much larger than in the case of chlorine. In contrast to the free chlorine, the free bromine still largely reacts with SO ₂ in the boiler (presumably to SO ₂ Br ₂ ), namely> 90%. Approximately in the boiler, a 100% Br ₂ conversion is assumed. Thus, for calculation purposes, the total intermediate Br ₂ load is divided by the molecular weight of Br ₂ (159.88 kg Br ₂ / kmol) and multiplied by the molecular weight of sulfur dioxide (64.06 kg S / kmol). With a corresponding addition by a factor of 1.09, the sulfur consumption due to the oxidative SO ₂ / SO ₃ conversion is also taken into account here, as described above.

The alternative procedure described here of a control with a concurrently calculated SO ₂ -SOLL content in the flue gas before boiler as a "controlled setpoint" of a primary control loop is always of interest if you do not need the required in alkaline washing reducing agent requirements for hypohalide reduction wants to cover over the residual SO ₂ from the boiler raw gas before quenching, but by an externally supplied, oxidation-stable reducing agent such as thiosulfate. In this case, the sulfur metering ramp will be set to values close to zero ("no need for residual SO ₂ as reducing agent"); the added sulfur therefore serves only for internal halogen consumption and instead of the residual SO ₂ from the crude boiler gas, for example, externally fed thiosulfate forms the reducing agent.

In the case of SO ₂ deficiency, free chlorine or bromine which penetrates into the clean gas is measured by direct measurement of the Cl ₂ or Br ₂ content in the clean gas after alkaline scrubbing (eg after induced draft, but mind before an optionally downstream SCR catalyst bed), preferably by means of an electrochemical measuring cell, such as the so-called chemosensor from Dräger Sicherheitstechnik (see [8]). The sample gas is continuously withdrawn from the flue gas channel in the bypass, dried and then analyzed in the chemosensor. Free chlorine (or free bromine) causes a voltage change in the measuring cell of the chemosensor, which is converted into a concentration. However, because of the sensor's large cross-sensitivity to the nitrogen oxides (NO _x ) contained in the clean gas upstream of SCR, the primary Cl ₂ readings should be continuously corrected for the NO _x -based Cl ₂ indication using the current NO _x gas content.

Alternatively, to control the Cl ₂ or Br ₂ levels in the clean gas after flue gas scrubbing (eg, after induced draft, but mind before any downstream SCR catalyst bed), instead of or in addition to the electrochemical measuring cell, one could also use another continuously indicating Cl Position ₂ - or / and Br ₂ - measuring device, eg a device based on near-infrared spectrometry.

In the case of chlorine, the pure gas measurement of penetrating free halogens is required SCR catalyst bed done, since the free chlorine in the clean gas passage through the SCR demonstrable - according to the SCR catalyst catalyzed chlorine Deacon reaction under the pure gas conditions (low residual chlorine, high water vapor content, about 300 ° C) - largely reacted back to HCl. However, this does not apply to free bromine (bromine-deacon reaction) and free iodine (Iodine Deacon reaction).

Further control of the sufficient provision of SO ₂ would also be possible, for example, by measuring the hypohalide content in the waste water of the alkaline wash.

With a sudden increase in the throughput of highly halogenated waste follows the Halide load in the waste water of the acid wash of the current total halogen freight in the flue gas - as explained - delayed, due to the residence time of the acidic Waste water in the acid scrubber circulation / scrubber sump.

In the case of such erratic freight increases thus the target SO ₂ content (be it the computationally controlled target SO ₂ content in the flue gas before boiler or via a conductivity and wastewater flow measurement directly controlled target SO ₂ residual content in the boiler raw gas before quenching ) despite the control intervention by the primary control loop is not sufficiently fast adapted to the current halogen total freight, so that it can lead in the meantime to a SO ₂ deficiency and consequently to an undesirable breakdown of eg free Cl ₂ or Br ₂ into the clean gas after alkaline scrubbing.

In order to avoid through breakthroughs caused by rapid cargo increases, the metered amount of sulfur must be raised in time and in the meantime increased as long, for example by 5-100%, preferably by 10-50%, to the requested by the primary loop sulfur again alone for the X ₂ Suppression and the NaOX reduction is sufficient.

To realize this increase, the target residual SO ₂ content in the boiler raw gas before quenching is reduced by up to 1000 mg SO ₂ / Nm ³ _tr via an "extended control loop". increases, for example, in the case of chlorine from a Cl ₂ content in the clean gas ≥ 0.5 mg Cl ₂ / Nm ³ _tr and increasingly with the level of Cl ₂ content measured in the clean gas. This ensures that there is always a sufficiently large excess of SO ₂ even in the event of an abrupt increase in the chlorine reactor in the crude boiler gas before quenching.

Alternatively, the amount of sulfur can also at the corresponding first increase of the Halide load in acid wastewater (as an indication of an erratic Increase in total halogen load), preferably proportional to observed rate of increase of conductivity.

Both measures, both the possible intervention due to the concentration free Halogens in the clean gas behind flue gas scrubbing as well as the possible intervention on Reason for a rapid increase in the halide load in acidic wastewater, can be used in the "extended control loop" together or separately.

The inventive method for the controlled suppression of free halogens may also apply mutatis mutandis to discontinuous waste disposal ("container operation") be used. In this case, the dosage of sulfur and / or to couple other sulfur carrier with the package task, i. to raise periodically and - depending on the halogen or halide content of the container - both in terms Height, time and duration of the associated sulfur dosage shot.

The amount of time, the amount of time and the time attached to the task the container size coordinated dosage of sulfur and / or other sulfur carriers can automatically read in individual bar codes to calorific value, Halogen type and halogen quantity of the individual containers fall back.

In the case that sulfur granules are metered in, the device is for metered addition Here too, a metering screw with subsequent pneumatic preferred Conveyor line to the primary furnace.

In the event that waste sulfuric acid is metered in, the metering device is used of the sulfur preferably a metering pump with subsequent nozzle or Nozzle, over which atomizing in the primary or secondary firebox is injected.

The inventive method has the advantage that free halogens such as Cl ₂ and / or Br _{2 are} eliminated by the controlled addition of sulfur or other sulfur carriers in the furnace equal to two points of the incinerator, namely once in the waste heat boiler (direct gas phase reaction with SO ₂ ) and in alkaline washing (hypohalide reduction with chemisorbed residual SO ₂ formed bisulfide). The controlled addition of sulfur proportional to the varying total halogen load (primary control loop) and the feedforward control with intermediate increase in the amount of sulfur when blowing free halogens into clean gas (extended control loop with feedforward control) ensures that on the one hand the minimum requirement for sulfur is covered, on the other hand the acidic or alkaline washing should not be unnecessarily burdened with oxidized sulfur compounds such as SO ₃ / SO ₄ ^2- (acidic wash) or SO ₂ (alkaline wash). Accordingly, there is no unnecessarily high sulfur consumption and thus no unnecessarily high alkali consumption, neither in the alkaline wash (consumption of NaOH), nor in a downstream wastewater treatment / heavy metal precipitation (eg consumption of Ca (OH) ₂ ), and thus ultimately no unnecessarily high Accumulation of residues to be dumped, such as calcium sulfate dihydrate CaSO ₄ x 2 H ₂ O.

literature

[1] HW Fabian, P. Reher and M. Schoen
"How Bayer incinerates wastes",
Hydrocarbon Processing, April 1979, p. 183

[2] RDGriffin
"A New Theory of Dioxin Formation in Municipal Solid Waste
Combustion "
Chemosphere Vol. 15 (1986), pp. 1987-1990;

[3] T. Geiger, H. Hagemeiner, E. Hartmann, R. Römer, H. Seifert
"Influence of sulfur on dioxin and furan formation in sewage sludge incineration",
VGB Kraftwerkstechnik 72 (1992), pp. 159-165;

[4] P. Samaras, M. Blumenstock, D. Lenoir, KW Schramm, A. Ketttrup
"PCDD / F Prevention by Novel Inhibitors: Addition of Inorganic S and N Compounds in the Fuel Before Combustion",
Environ. Sci. Technol. 34 (2000), pp. 5092-5096

[5] DA Oberacker, DR Roeck, R. Brzezinski
"Incinerating the Pesticide Ethylene Dibromide (EDB: a Field-Scale Trial
Burn Evaluation Environmental Performance ",
Report EPA / 600 / D-88/198, Order no. PB89-118243 (1988)

EP 0 406 710

[7] W. Oppenheimer, K. Marcek: "Thermal disposal of production waste",
Disposal Practice 6 (2000), pp. 29-33

[8] Dräger Sicherheitstechnik: Product specification for DrägerSensor Cl ₂ - 68 09 725

Figures and examples

Figur 1

Schema einer Abfallverbrennungsanlage (Sonderabfall-Verbrennungsanlage VA1 im BAYER-Entsorgungszentrum Leverkusen-Bürrig)

Figur 2

Geschlossene Schwefelbilanz über Feuerung, Kessel und saure Wäsche für die Verbrennung hochchlorierter Abfälle

Figur 3

Chlorbilanz (HCl-Austrag mit dem Abwasser der sauren Wäsche bzw. NaCl-Austrag mit dem Abwasser der alkalischen Wäsche)

Figur 4

Primärer Regelkreis

Figur 5

Schwefel-Dosierrampe für die Verbrennung hochchlorierter Abfälle

Figur 6

Ermittlung eines Punktes der linearen Schwefel-Dosierrampe

Figur 7

Sprunghafte Anhebung der Halogengesamtfracht im Rauchgas und demgegenüber verzögerter Anstieg der Halogenidfracht im sauren Abwasser

Figur 8

Beispiel für Cl₂-Durchbruch bei sprunghafter Frachtanhebung unter Nutzung allein des primären Regelkreises

Figur 9

Erweiterter Regelkreis mit Störgrößenaufschaltung

Figur 10

Korrektur der Cl₂-Scheinanzeige infolge NO_x-Querempfindlichkeit eines Cl₂-Messgeräts im Reingas vor SCR

Figur 11

Aufgeprägte Chlorfrachtsprünge zum in nachfolgender Figur 12 dargestellten Versuch unter Nutzung des erweiterten Regelkreises

Figur 12

Bei Nutzung des erweiterten Regelkreises mit Störgrößenaufschaltung ist trotz sprunghafter Frachtanhebung ein Cl₂-Durchbruch nicht zu beobachten

Figur 13

Geschlossene Schwefelbilanz über Feuerung, Kessel und saure Wäsche für die Verbrennung hochbromierter Abfälle

Figur 14

Brombilanz (HBr-Austrag mit dem Abwasser der sauren Wäsche bzw. NaBr-Austrag mit dem Abwasser der alkalischen Wäsche)

Figur 15

Vergleich der Leitfähigkeit von wässrigen HCl- und HBr-Lösungen

Figur 16

Rückkonversion von Cl₂ zu HCl beim Reingasdurchgang durch die nachgeschaltete SCR

Show it:

FIG. 1

Scheme of a waste incineration plant (hazardous waste incineration plant VA1 at the BAYER Disposal Center Leverkusen-Bürrig)

FIG. 2

Closed sulfur balance on firing, boilers and acid laundry for incineration of highly chlorinated waste

FIG. 3

Chlorine balance (HCl discharge with the waste water of the acid wash or NaCl discharge with the waste water of the alkaline wash)

FIG. 4

Primary control loop

FIG. 5

Sulfur dosing ramp for the combustion of highly-chlorinated waste

FIG. 6

Determining a point of the linear sulfur metering ramp

FIG. 7

Abrupt increase of the total halogen load in the flue gas and, in contrast, delayed increase of the halide load in the acidic wastewater

FIG. 8

Example of a Cl ₂ breakthrough with a sudden increase in freight using only the primary control loop

FIG. 9

Extended control loop with feedforward control

FIG. 10

Correction of Cl ₂ indication due to NO _x cross sensitivity of a Cl ₂ meter in the clean gas before SCR

FIG. 11

Impacted chlorine jumps to the experiment shown in Figure 12 below using the extended control loop

FIG. 12

When using the extended control loop with feedforward control, a Cl ₂ breakthrough is not observed despite a sudden increase in freight

FIG. 13

Closed sulfur balance on firing, boilers and acid laundry for incineration of highly brominated waste

FIG. 14

Brombilanz (HBr discharge with the waste water of the acid wash or NaBr discharge with the waste water of the alkaline wash)

FIG. 15

Comparison of conductivity of aqueous HCl and HBr solutions

FIG. 16

Reconversion of Cl ₂ to HCl during the clean gas passage through the downstream SCR

FIG. 1 shows a typical waste incineration plant (here the hazardous waste incineration plant). plant VA1 at the BAYER Disposal Center Leverkusen-Bürrig) with Containers for solid waste and containers 1 and liquid waste 2, the Rotary kiln 3, the afterburner 4, the waste heat boiler 5, the quencher 6, the acid rotary atomizer scrubber 7, the alkaline rotary atomizer scrubber 8, the condensation EGR 9, 10 suction trains, a downstream SCR denitrification plant 11 and the fireplace 12.

FIG. 2 shows, by way of example for the case of chlorine, ie the combustion of highly-chlorinated waste, a "closed sulfur balance via firing, boiler and acid wash". This representation provides evidence that in the boiler about 3% of the total chlorine load as an intermediate Cl ₂ still react in the boiler by means of SO ₂ back to HCl and SO ₃ ; The SO _{3 formed} is found in the acidic quenching wastewater as SO ₄ ^2- again. The operational tests for FIG. 2 were carried out under a constant high sulfur supply with progressively increasing overall chlorine load. The abscissa of the diagram is the total chlorine content, based on the dry flue gas volume flow, thus described as mg Cl _ges / Nm ³ _tr . Ordinate of the diagram is the "sulfur mass flow", contained in the flue gas side SO ₂ or in the waste water side SO ₄ ^2- , also also based on the dry flue gas volume flow of about 40 000 Nm ³ _tr. / H at the investigated plant (mg S / Nm ³ _tr. ). As indicated in FIG. 2, some SO ₂ measurements are behind the acidic wash, ie in the acid-washed clean gas before the alkaline scrubber, in order to prove that the raw-gas-side SO ₂ (after boiler / before quench) passes the acid scrubber area as expected.

Figure 3 shows the associated chlorine balance, now including the alkaline wash (alkaline rotary atomizer scrubber (ARW)) to exemplify that - with sufficient supply of sulfur - 99% of total chlorine load as HCl in the acidic laundry and only 1% of total chlorine load as Cl ₂ get into the alkaline wash and there (over the residual SO ₂ in the boiler raw gas before quenching) are ultimately reduced to the stable chloride.

FIG. 4 shows, by way of example for the case of chlorine, the primary control circuit with use of the chlorine-specific sulfur metering ramp 13, guided by the residual SO ₂ -SOLL value 14 a in the boiler raw gas 14, before quenching on the basis of the halide load in the quenching waste water; The latter is determined from the HCl content 15 in the wastewater (determined by means of temperature-compensated conductivity measurement 16) by multiplication with the wastewater volume flow 17 (MID measurement). The metering of the required mass flow of sulfur granules 18 to the head of the primary furnace (rotary kiln) 3 via the metering screw 19 and a pneumatic transport line 20. The manipulated variable is the speed of the metering screw drive 21. This speed is changed via the PI controller R.3332 22. This regulator 22 continuously compensates for the residual SO ₂ -IST value 14a measured behind the waste heat boiler 5 with the residual SO ₂ -SOLL value 23 required according to the sulfur metering ramp 13.

FIG. 5 shows, again by way of example in the case of chlorine, the operationally predetermined chlorine-specific metering ramp used in the primary control circuit (FIG. 4). For their determination, 6 combustion tests with different total loads were carried out. The main parameters of these operating tests are given in Table 1. In each of the operating experiments, the throughput of a highly chlorinated liquid waste mixture of dichloropropane DCP and chlorinated hydrocarbon CKW (each with known chlorine contents) was kept constant. The respective chlorine load (based on the dry flue gas volume flow of about 40000 Nm ³ _tr. / H) can be read as the abscissa in Figure 5; the ordinate in FIG. 5 indicates the necessary residual SO ₂ desired value (minimum SO ₂ residual content) in the boiler raw gas before quenching, based on the dry flue gas volume flow.

FIG. 6 for experiment 4 in table 1 exemplifies the procedure for determining a point of the sulfur metering ramp. The diagram shows the contents of residual SO2 in the boiler raw gas (left ordinate) and of free chlorine in the clean gas after alkaline scrubbing, measured downstream of the induced draft (right ordinate) as a function of the test time. At first, a high residual SO ₂ content in the boiler raw gas was preselected and then slowly lowered at the start of the experiment. From a residual SO ₂ content of about 1400 mg SO ₂ / Nm ³ _tr in the boiler raw gas before quenching, the Cl ₂ concentration in the clean gas before SCR starts to increase slightly until after about 12:30 h at about 500 mg residual SO ₂ / Nm ³ _tr. To a noticeable increase in free chlorine (Cl ₂ breakthrough) comes. The SO ₂ residual content, from which the Cl ₂ concentration in the clean gas rises sharply, and the associated Cl _ges concentration in the flue gas (here about 36 g Cl _ges / Nm ³ _tr. ) Define a point of the sulfur metering ramp. The further experiments prove that the sulfur dosing ramp is actually a straight line.

As in FIG. 7, a deliberate jump in the increase in the throughput of halogens, again using the example of chlorine - shows, which follows over the wastewater of the acid wash indirectly determined halide load of the current total halogen load in the flue gas delayed after, due to the size of the scrubber sump.

FIG. 8 shows the shortage of SO ₂ due to a sudden increase in freight due to this delay as a result of trailing detection of the current total halogen load as well as the still-observable Cl ₂ breakthrough into the clean gas after alkaline scrubbing when the primary control circuit is operated alone. After the primary control loop has been put into operation at 1:45 pm, the primary control circuit initially restores the SO ₂ residual content in the boiler raw gas from the preselected value to the value actually required according to the sulfur metering ramp. At 14:35 o'clock, the deliberately induced jump in the chlorine reactor from 900 kg / h to 1400 kg / h took place here (see Figure 7). Due to the delayed detection of the rapidly increasing current total chlorine load and thus delayed tracking of the residual SO ₂ content, there is an increase in the Cl ₂ concentration in the clean gas after 45 min (16:15 h) and finally a "Cl ₂ breakthrough" Values >> 5 mg Cl ₂ / Nm ³ _tr in the clean gas. When the SO ₂ residue finally reaches the required final value, the Cl ₂ breakthrough is also completed.

Such Cl ₂ breakthroughs can be prevented with the "control loop with feedforward control", which is shown in FIG. 9 and has been extended compared to the primary control loop. According to the extended control concept, the residual SO ₂ -SOLL value 14a in the boiler raw gas 14 before quenching is not conducted solely via the sulfur metering ramp 13 in accordance with the lagging chloride load of the acid wastewater, and thus the amount of sulfur 18 added in gradually increased. Rather, the residual SO ₂ -SOLL value 14a in the boiler raw gas 14 is increased in the interim deliberately before quenching as soon as pure chlorine is to be measured in the clean gas after alkaline scrubbing 8 / downstream of the induced draft 10 (but, of course, still upstream of the SCR catalyst bed). For this measurement of the free chlorine, a Chemosensor 25 from the company Dräger Sicherheitstechnik is preferably used. The sample gas is continuously withdrawn from the flue gas channel, dried and analyzed. The free chlorine causes in the measuring cell of the chemosensor 25 a voltage change, which is converted into a concentration. Because of the large cross-sensitivity of the sensor 25 with respect to the nitrogen oxide NO _x 26 which is still present in the clean gas before SCR, the primary Cl ₂ measured values from the sensor 25 are corrected with respect to the NO _x -induced dummy display with device-specific correction factors 27 (calculation of the dummy display 28, subtraction of FIG Apparent indication of primary Cl ₂ reading 29).

The Cl ₂ indication ΔCl ₂ (28) as a result of NO _x cross sensitivity of the installed Dräger measuring cell 25 follows a simple device-specific correction equation, for example in the form ΔCl ₂ / ppm = a * NO _x / (mg / Nm _tr. ). Given occasional high levels of NO _{x in the} clean gas upstream of SCR, it is advisable - given the low Cl ₂ threshold - to apply a correction equation of the form ΔCl ₂ / ppm = a '* [(NO _x / (mg / Nm _tr. )] ² - b '* NO _x / (mg / Nm _tr. )] and to ensure the coefficients a' and b 'of this correction equation by appropriate operational measurements; This can for example be done directly on the operating flue gas with NO _x -rich, but chlorine-free driving (measurement results in Figure 10).

As FIG. 9 furthermore shows, the NO _x -corrected Cl ₂ reading is from a preselectable Cl ₂ content 30 in the clean gas of, for example, 0.5 mg Cl ₂ / Nm ³ _tr., By the regulator R.3401 31 in an additional SO ₂ request implemented, which can be raised in the amplifier 32 again by a preselectable gain factor 33, for example the factor 10. This additional SO ₂ request is added to the SO ₂ request from the primary control loop in the "disturbance adder" 34. Thus, the SO ₂ -SOLL value 23 increases by z. B. 1000 mg SO ₂ / Nm ³ _tr. The controller 22 is now again equal to the residual SO ₂ -IST value 14a measured downstream of the waste heat boiler 5 with the residual SO ₂ -SOLL value 23 increased in accordance with the interference variable connection described above from

This ensures that there is always a sufficiently large SO ₂ supply in the event of a sudden chlorine increase.

As a redundant safety measure against Cl ₂ breakthroughs, the temporal increase in chloride load in the quench wastewater can also be utilized, eg via a DIF (differentiation of the time increase 24) in order to increase the residual SO ₂ in the event of a rapid increase. Target value 23 to be increased immediately.

All measures for temporary raising of the residual SO ₂ -SOLL value 23 via the solely on the sulfur addition ramp 13 lagging requested residual SO ₂ -SOLL value addition may together (addition in disturbance adding unit 34), or be used separately.

In order to demonstrate the effect of the extended control loop with feedforward control, large jumps in the total chlorine load were purposefully brought about in a further operating test, cf. Figure 11. Despite the strong and rapid cargo changes shown in Figure 11, the enhanced control loop (Figure 9) provided the excellent result shown in Figure 12: When the extended control loop is started at 12:40, the residual SO ₂ content initially falls to sulfur -Dosierrampe the total chlorine load corresponding value of about 1200 mg SO ₂ / Nm ³ _tr. Back. After the chlorine freight reduction from 1500 kg / h to 1100 kg / h at 13:10, the SO ₂ residual content in the boiler raw gas continues to decrease. At 14:30 o'clock then the chlorine clothing is suddenly increased. As a result of the occurrence of free chlorine> 0.5 mg / Nm ³ _tr in the clean gas, the regulator R. 3401 (see FIG. 9) then causes a leading increase in the residual SO ₂ -SOLL value and thus a rapid increase in the CO ₂ actual SO ₂ residual content in the boiler raw gas before quenching by about 1000 mg SO ₂ / Nm ³ tr. Accordingly, there is no Cl ₂ breakthrough, but rather the Cl ₂ content in the clean gas immediately returns to values <0.5 mg / Nm ³ _tr. Back. Note: At 16:10 there was a brief disruption of the sulfur dosing screw; As a result, the SO ₂ residual content dropped briefly for a short time, so that in the clean gas a small peak of free chlorine once again came (16:15 o'clock). In contrast to the primary control circuit (see FIG. 4) alone, only extremely small Cl ₂ peaks in the concentration range << 5 mg Cl ₂ / Nm ³ _{tr are} detected as the answer of the extended control loop to comparable heavy cargo jumps.

The examples described so far were essentially limited to the Combustion of waste containing chlorine. But how the closed sulfur balance for Occupy bromine in Figure 13 and the bromine balance in Figure 14, meet the earlier on For example, the basic correlations of chlorine also apply to the others Halogens - like the bromine considered here as another example - too, though are far higher levels of free halogens in the game.

Analogous to FIG. 2 for the case of chlorine, FIG. 13 shows, in the case of bromine, that in the boiler a Br ₂ content of on average about 61% of total bromine (instead of 3% in the case of chlorine) is converted. Note: The brominated liquid waste burned in the experiment contained about 25% bromine and about 3% chlorine; this chlorine is taken into account in FIG. 13, ie the evaluation result shown is "chlorine-purified".

Analogous to FIG. 3 for the case of chlorine, FIG. 14 shows, in the case of bromine, that also here only about 1% of the total load gets into the alkaline wash, i. Despite the a significantly higher proportion of free bromine in the total bromine total freight sufficient sulfur supply - here too 99% of total bromine in the acidic laundry deposited.

Lastly, FIG. 15 shows the comparison of the conductivity (temperature-compensated to FIG 20 ° C) of aqueous HCl and HBr solutions. With the same conductivity is the Mass content of bromide compared to the mass content of chloride - accordingly the molar mass ratio HBr / HCl = 80.948 / 36.465 = 2.22 - a little more than twice as big.

Many highly chlorinated liquid wastes contain no bromine or only little bromine. The By contrast, most high-brominated liquid wastes contain not only bromine but also noticeable Chlorine. When evaluating the conductivity measurements, in the case of such bromine and at the same time chlorine-rich wastes, without the later calculation of sulfur demand to make a significant mistake, e.g. solely from bromine (as main halogen) go out, i. only on the conductivity curve of aqueous bromide solutions provided that - in the subsequent calculation of sulfur demand - again only from bromide emanates, i. the corresponding molar mass of HBr used. In this way, when evaluating the conductivity measured values instead the amount of chloride present is equivalent in terms of sulfur demand Bromide amount "determined.

Finally, FIG. 16 shows the above-mentioned fact that the free chlorine in the clean gas passage through a downstream clean gas SCR according to the Chloro-Deacon Reaction Catalyzed on the Metal-Oxide-Rich SCR Catalyst - Under the pure gas conditions available there (low residual chlorine, high Water vapor content, about 300 ° C) - largely reacted back to HCl.

Claims (26)

A method for low-corrosion and low-emission co-incineration of highly halogenated liquid waste in waste incineration plants, the waste incineration plant at least one furnace (3), a waste heat boiler (5), a multi-stage flue gas scrubbing consisting of acidic laundry (7) and alkaline laundry (8), characterized in that sulfur or a suitable sulfur carrier is metered into the firebox (3) in a controlled manner as a function of the total halogen load and halogen type. A method according to claim 1, characterized in that the amount of sulfur is metered in proportion to the current total amount of chlorine, bromine or iodine in the waste. A method according to claim 1 and 2, characterized in that the amount of sulfur according to an operationally determined sulfur dosing ramp, the required in the current halogen total cargo SO ₂ residual content in the raw gas boiler (before quenching) for each chlorine, bromine or iodine rich waste determines, is metered regulated. A method according to claim 1 to 3, characterized in that the linear sulfur metering ramp for each chlorine-, bromine- or iodine-rich waste is determined operationally by for at least one major chlorine, bromine or iodine freight in waste the minimum required SO ₂ Content in the boiler raw gas is determined, in which - in the stationary operating state - no or only below a predetermined limit amount of free chlorine, bromine or iodine in the clean gas after flue gas scrubbing can be detected. A method according to claim 1 to 4, characterized in that the current flue gas total halogen total freight is approximately continuously determined as halide load in the wastewater of the acidic flue gas scrubbing, ie as a product of halide concentration and waste water volume flow continuously. Method according to one of claims 1 to 4, characterized in that the current flue gas-side total halogen content on the flue gas side, via halogen and hydrogen halide species measurements in the boiler raw gas before quenching (boiler) and the dry flue gas volume flow or a proportional to the flue gas volume flow size as the steam capacity of the boiler, is determined continuously. Method according to one of claims 1 to 6, characterized in that the amount of sulfur corresponding to the total halogen load in the flue gas or the halide load in the waste water of the acidic laundry according to the sulfur metering ramp, in the short term by 5-100%, preferably 10-50%, is exaggerated as soon as free chlorine, bromine or iodine in the clean gas after the flue gas scrubbing, but even before an optionally downstream SCR catalyst bed is measured. Method according to one of claims 1 to 6, characterized in that the amount of sulfur corresponding to the total halogen load in the flue gas or the halide load in the waste water of the acidic laundry according to the sulfur metering ramp, in the short term by 5-100%, preferably 10-50%, is increased as soon as a rapid increase in the halide concentration in the wastewater of the acidic laundry is measured. Method according to one of claims 1 to 8, characterized in that the sulfur is added in the form of solid sulfur, liquid sulfur or waste sulfuric acid. Method according to one of claims 1 to 9, characterized in that solid sulfur is metered in pelletized or granulated form via controllable metering. Method according to one of claims 1 to 10, characterized in that the solid sulfur is fed by pneumatic conveying in the primary furnace. Procedure according to one of claims 1 to 9, characterized in that the waste sulfuric acid is metered via controllable metering pumps to the primary or secondary combustion chamber. A method according to any one of claims 1 to 9 or 12, characterized in that the waste sulfuric acid is fed into the primary or secondary combustion chamber via an atomizing nozzle or nozzles. Method according to one of claims 1 to 13, characterized in that at periodically changing halogen total freight in the flue gas due to the zeittätakteten task of halogen-rich individual packs bound to the application clock, in terms of height, time and duration matched to the container size dosage of sulfur and / or other sulfur carriers he follows. A method according to claim 14, characterized in that bound to the charging cycle, with respect to height, timing and time abstimmente on the container size Abstimmente dosage of sulfur and / or other sulfur carriers on automatically read individual bar codes to calorific value, Halogenart and halogen amount of the container. Method according to one of claims 1 to 15, characterized in that the hypohalide reduction in the alkaline scrubbing takes place there via the therefrom from the residual SO _{2 of} the boiler raw gas formed in-process bisulfide and at the same time or solely by an externally supplied reducing agent such as thiosulfate Method according to one of claims 3 to 16, characterized in that an operationally determined for pure chlorine wastes sulfur metering ramp also for the combustion of halogen mixtures containing chlorine in addition to other halogens is used. Waste incineration plant with combustion chamber (3), a waste heat boiler (5), a multi-stage flue gas scrubbing consisting of acidic laundry (7) and alkaline laundry (8), characterized in that the waste incineration plant control devices for the controlled addition of sulfur and / or other sulfur carriers in the primary or secondary combustion chamber (3), (4). Waste incineration plant according to claim 18, characterized in that it contains metering units and delivery units for the controlled metered addition of sulfur or other sulfur carriers in the primary or secondary combustion chamber (3), (4). Waste incineration plant according to claim 19, characterized in that the unit for the controlled metered addition of sulfur or other sulfur carriers is a controllable delivery unit such as a vibrating trough or a metering screw (19). Waste incineration plant according to claim 20, characterized in that the aggregate for the regulated metered addition of the waste sulfuric acid is a controllable metering pump and is injected via a nozzle and / or a nozzle in the primary or secondary combustion chamber (3), (4). Waste incineration plant according to one of claims 18 to 21, characterized in that the control device consists in a primary control loop with nominal value management of the continuously measured residual SO ₂ content in boiler raw gas before quenching or in a corresponding extended control loop with additional disturbance variable, wherein the primary Control loop controls the sulfur addition according to a sulfur metering ramp proportional to the current total halogen load in the flue gas or halide in acidic wastewater. Waste incineration plant according to one of claims 19 to 21, characterized in that the control device is in a primary control circuit with target value of the concurrently calculated SO ₂ content in the flue gas in front of the boiler or in a corresponding extended control loop with additional disturbance variable, wherein the The primary control circuit regulates the sulfur addition on the basis of a continuous halogen-specific conversion calculation over the speed of the metering unit taking into account the delivery characteristic of the metering unit proportional to the current total halogen load in the flue gas or halide in acid wastewater. Waste incineration plant according to claim 22 or 23, characterized in that the corresponding extended control loop - at the beginning of Cl ₂ breakdown in the clean gas and / or rapid increase of the halide content in the acid wastewater - the sulfur addition temporarily increased (disturbance variable connection). Waste incineration plant according to one of claims 22 or 24, characterized in that a sulfur metering ramp according to claim 4 is used in the control loop. Waste incineration plant according to one of claims 22 to 25, characterized in that the current halogen charge is determined according to one of claims 5 or 6.

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