WO1988001536A1 - Process for simultaneous removal of dustlike and gaseous impurities from flue gases, industrial, synthetic, possibly radioactive, gaseous substances or the like (zero emission) - Google Patents

Abstract

A process for removing from flue gases, industrial waste gases, exhaust fumes, combustion gases from natural fires, radioactive emissions from nuclear reactor disasters or the like, their dustlike and gaseous impurities (zero emission). After the gas has been cooled to a temperature between 20° and 60°C and sprayed with water to remove hydrohalogen impurities, an artificial mist of particles smaller than 25 mum is generated and the gas is maintained in this mist-like state for the time necessary for the toxic substances to dissolve in and react with the mist droplets. The saturated mist droplets are then precipitated by finely spraying the gas flow with a mist-dissolving substance. To form the (active) mist, an aqueous solution of a reagent able to react chemically with the toxic components and to form water-soluble reaction products, preferably a metal hydroxide, ammonia and/or ammonia water, is sprayed into the gas. In a first stage, a solution containing 50 % active substance is used, and in a second stage, a solution containing 30 % active substance. A metal carbide, oxide, hydroxide, or hydrate-forming chemical substance, for example phosphate or the like, is used to precipitate the mist droplets.

Description

A method for simultaneous cleaning (zero-emission) of smoke, industrial and synthesis gases or the like -. Gege ^¬ radioactive appropriate, - gaseous media from their dust and gaseous impurities

The invention relates to a method for the simultaneous purification (Nu emission) of smoke and industrial exhaust gases, combustion gases from combustion engines, natural fires, radioactive emissions from nuclear reactor disasters or the like. Gaseous media from their dusty and g-shaped impurities.

The cleaning of smoke, exhaust, industrial and synthesis gases or similar gaseous media from their dust-like and water-soluble impurities is still an inadequately solved problem. is still generally carried out today in such a way that the gas is subsequently subjected to a treatment which is matched to a type of impurity. In this sense, today the gases are first freed from their dust-like impurities in dry, wet or electrostatic filters, whereupon the gaseous impurities, in particular the sulfur oxides and nitrogen oxides, are eliminated in absorption processes which are matched to the impurities or by catalytic decomposition methods. Here, the cleaning of sulfur dioxide impurities predominantly takes place by oxidizing sulfur trioxide and binding to lime to form gypsum, which is now obtained in such an amount that sufficient utilization is not possible and the reaction product is already threatening to become a burden. It is known from DE-OS 33 12 890 a gas cleaning process in which the combustion gas is passed through a heap of metal oxides as an active mass and, in the presence of nitrogen oxides, manganese dioxide (Mn02-containing pellets containing high porosity) and the impurities are separated from the metal oxides In this way, the impurities contained in the gases are brought into a form with the help of a special cleaning race (moxides) in which a binding to metal oxides or a detoxification of the pollutant is possible, so that overall, in a single process step, the greatest possible exemption The well-known process has largely proven itself, but there are non-usable and difficult-to-regenerate reaction products. This process is fundamentally not suitable for simultaneous cleaning of the smoke and exhaust gases from NOx and S02 pollutant e Nor can it be used for the high throughputs of the exhaust gases to be cleaned, which must be connected with laborious cycles a cleaning material. It also requires the exhaust gas to be cleaned to be freed from its physical impurities beforehand.

It is also known from DE-OS 24 53 488, the method in which flue gas and cooling water plumes are entered in cross flow into the cooling air rising in a natural flow cooling tower. By this procedure, however, a dilution takes place, but not a remarkable reduction in nitrogen oxide or sulfur dioxide impurities. The present invention has for its object to provide a method by means of which each type of flue and process gases can be freed from all essential physical and chemical impurities simultaneously in one operation. The invention consists in that, after cooling to a temperature between 20 ° and 60 ° C., spraying water with a particle size of less than 25 generates artificial active mist and the gas during a solution to oxidize and react the (S02 and NOx) -Schadstoffe is held in the Nebeltröp chen sufficient time in nebelgetrübtem state Wora the pollutant-laden mist droplets niedergeschlag be of a fine distribution in the gas stream sprayed mist resolving agent with the aid .. ^•

The invention provides a method by means of which smoke and process gases can be freed from all essential physical and chemical impurities up to the zero emission limit simultaneously in one work step. The process according to the invention is based on the surprising finding that, in particular, the toxic gaseous pollutants nitrogen oxides and sulfur dioxide concentrate almost quantitatively in the liquid phase in a foggy atmosphere, so that they can be precipitated without difficulty. Here, the nitrogen oxides contained in the gas act as catalysts for converting the sulfur dioxide into sulfur trioxide within a short period of time, which is bound directly in the fog droplets as sulfuric acid, while the conversion of the nitrogen monoxide into nitrogen dioxide - with subsequent solution in the fog droplets as nitric acid - in Oxygen environment oh catalytic support is provided. The basis for the quick and practically quantitative solution of the pollutants is the large liquid heat reaction area caused by the formation of the mist droplets and their even distribution in space, which ensures that the molecules come into contact with the solution practically simultaneously with the oxidation. Other essential advantages of the method of the invention are also the fact that, on the one hand, the dust-like impurities are also precipitated in this way in one work step due to the wetting, and that no complex device is required to carry out the method. Rather, after minor changes, reaction towers of the known type of chimney cooling towers can be used, so that with the aid of the method of the invention, a significant relief of the atmosphere from the essential pollutants is possible quickly and immediately.

In an advantageous embodiment of the invention, an aqueous solution of a reagent that reacts chemically with the dissolved oxidized pollutant components to form a (soluble) reaction product, preferably a metal hydroxide or ammonia or araronia water, can be sprayed into the gas to form (active) nebi. Through the use of such a reagent, an immediate chemical binding of the pollutant as a salt is achieved immediately after its dissolution in the mist droplet, which on the one hand accelerates the dissolution of the gaseous pollutant and furthermore facilitates or suppresses the precipitation. b is accelerated. In addition, the proportion of water is in turn immediately available for solving pollutants and even through the eh Mixing reaction increases the water content available for the solution of pollutants. As a chemically reactive reagent with the dissolved oxidized pollutant components, sodium, potassium or magnesium hydroxide can be used as a 10-50%, preferably 30-45% solution or suspension, based on the amount of pollutant contained in the gas, in a stoichiometric amount . However, ammonia or ammonia water in a sub-stoichiometric amount of 80-98%, preferably 85-95%, based on the amount of pollutant contained in the gas, can also be used with equally good results. By limiting the volatile

10 c

Active agents to a stoichiometric maximum of 98% are prevented from possible re-soiling of the cleaned flue gas by unreacted ammonia, the rest of the active agents required for complete re-reaction and binding of the oxidized pollutants being covered according to the stoichiometry by other non-volatile active agents.

In a particularly advantageous embodiment of the invention, the addition of the aqueous solution eriol in two stages such that in a first stage an approximately 50% hydroxide solution for the purpose of dissolving and re-reacting the oxidized sulfur dioxide impurities and after

20 reaction time of between about 3 and 5 minutes in a second hour an approximately 30% hydroxide solution is added for the purpose of solution and re-reaction of the oxidized nitrogen oxide impurities during a reaction time of between about 15 and 25 minutes. In this way, a selective solution and precipitation of the sulfur dioxide and nitrogen oxide impurities is achieved in such a way that in the first stage the sulfur dioxide with catalytic support from the in the G Contained nitrogen oxides oxidized and then absorbed, umreagie and precipitated, while in the second stage for a reaction time of about twenty minutes, the oxidation, absorption, Umreagi tion and precipitation of the nitrogen oxide impurities takes place.

The use of sodium hydroxide in the first stage forms a reaction product of hydrated sodium sulfate (Glauber's salt), in which case the reaction is expediently carried out at a temperature v above 32.4 ° C., preferably at 45 ° to 50 ° C., in addition to that .r Precipitation of the sodium sulfate 5 - 15%, advantageously 8 - 12% of anhydrous sodium sulfate is sprayed and the precipitated sulfate is hydrated with warm water from an external source up to sodium sulfate D-carbohydrate. In this way, not only is a further processability of the coupling product formed, but moreover a further considerable process advantage is achieved insofar as a Glauber's salt has a very low melting point of 32.4 ° C at an oh heat of fusion, so that the material formed temperature at work accumulates in practically water-liquid form and thus drips off automatically in the reaction tower. The resulting broad advantage is that due to the low viscosity of the material, the raitführung solid materials, especially heavy metals, can be easily filtered out. Finally, to improve the economics of the process, a large part of the low enthalpy heat contained in the flue gas can be recovered in the form of the heat of fusion contained in the Koppe product and used for other purposes. It may be necessary, depending on the concentration of sulfur dioxide in the exhaust gas, to repeat the (first) reaction stage several times in such a way that approximately 1,500 mg of sulfur dioxide per m ^{3 of} exhaust gas di (first) absorption stage is carried out once. The products obtained in the first adsorption stage are advantageously deducted from the products obtained in the second reaction stage for reasons of better usability of the reaction products of both stages, which products are expediently collected and further processed outside the reaction tower.

10

In the case of cleaning flue gases from a coal-fired power plant, the use of fuels with a high sulfur content can be of considerable use because of the advantages described above, contrary to the previous practice, which on the one hand has a lower market price than low-sulfur fuels. own substances and through which, on the other hand, the efficiency of the plant by recovering both the heat released during the cooling of the gas from 120 ° to about 50 ° C and the heat of fusion stored in the Glauber's salt considerably from previously around 35% by over 15% to over 50% d energy of the fossil energy source used can be improved.

20th

The active liquid is expediently sprayed in up to one

Supersaturation of the gas of at most 105%, preferably between 102.5 and 104.5% relative air humidity. Here is before or in place d spraying water. Reaction liquid by means of Air & _ _c-assisted nozzles and the enrichment in the Spezialfälleπ to clean the gas with the aid of steam from power plants - to close to d Saturation limit - possible. Likewise, the water can be sprayed in place with compressed air with pressurized oxygen, whereby an enrichment of the water with dissolved oxygen is achieved, which partially escapes into the atmosphere in the secondary phase and accelerates the oxidation of the harmful gases regardless of whether they are still in d Gas phase or - in the form of nitrous acid already dissolved form vo. In this case, the nitrous acid is oxidized in the liquid phase in nitric acid and reacted to the nitrate.

The removal of the hydrogen halide impurities (HF, HC1) and any dust constituents is advantageously carried out during the cooling phase of the flue gas, which in any case is associated with the separation of the condensate. Sodium, potassium or magnesium hydroxide is sprayed into the cooling exhaust gas stream as a 10-50%, preferably 45% solution in three to four times the stoichiometric amount, based on the amount of halocarbon, contained in the gas , the droplet size is suitably about 500 microns. An intensive droplet separation then precipitates the condensate droplets.

The suppression of pollutant or Salt-laden droplets can be made in any known manner. However, it is expediently carried out using a metal carbide, for example calcium, magnesium aluminum or manganese carbide, or the corresponding metal oxides or metal hydroxides, and further hydrate-forming substances or phosphates, preferably disodium monohydrogen phosphate, sodium sulfate or carbon individually or in a mixture with each other in an amount between 1 and 5, effective material per cubic meter of fog air. Smoke gas. The low-impact agent, which is advantageously used with a particle size of less than 100 .mu.m, is expediently used in an amount which is 15% lower than the amount required for complete binding of the water content d active mist droplets. In terms of apparatus - insofar as there are lower throughputs of up to about 50,000 m ^{3 of} smoke or exhaust gas per hour - the loaded nebula is expediently precipitated with the aid of reaction apparatuses in which the gas or elastic or metallic lines are arranged by means of horizontal single or double windings . in vertical loops of pipes laid for the purpose of oxidation and chemical re-reaction, misting and precipitation and in which the reaction time required for the oxidation and re-reaction misting and precipitation of the mist can be ensured for between 20 and 30 minutes. In so far as it concerns the purification of larger amounts of gas, the active mist generation absorption and re-reaction of impurities and precipitation of loaded active mist, on the other hand, is expediently carried out with the aid of natural train reaction towers which have multi-stage built-in active mist generation and precipitation devices.

The materials resulting from the reaction and precipitation are immediately accessible for further processing. So can contained in the low impact or Nitrate obtained in the second stage is reacted with ammonium chloride or ammonium hydrocarbonate to form ammonium nitrate, while magnesium sulfate obtained in the first reaction stage be worked up by thermal decomposition and washing with sodium sulfite and thermal decomposition of the sodium hydrosulfite thus formed to sulfur oxide rich gas. The nitrate accumulation from the second active mist dissolving stage can also be worked up thermally to N02 rich gas.

The invention has been described above on the basis of its essential field of application - namely the purification of the gases occurring in industry from their pollutants - but it can also be used in other areas, in particular in the fight against natural fires and the cleaning of the atmosphere above the nuclear reactor after one Accident associated with the emission of radioactivity, in which the following fission product quantities are released for a bructor (fission product quantity in 1 T fuel - 80% uranium oxide, ~ 20% plutoπiu oxide; combustion: 100000 MW; fission product content 10%; 100 d cooling time):

Element fission product quantity Element fission product quantity

Kr 0.32 Pd 7.30

Xe 10.1 Te 2.47

J 1.29 Cs 10.1

Rb 0.38 Ba 3.29

Sr 1.36 La 3.08

Y 0.72 Ca 6.73

Zr 7.59 Pr 2.72

Nb 0.18 Nd 10.1

Mo 8.65 µm 1.29

Tc 2.45 Sm 3.05

Ru 9.96 Eu 0.39

Rh 2.70 All of the nuclides listed in the table are in a dangerous cloud, which can flow out of the reactor in the event of a nuclear reactor accident, where it is caught by the air flow and is widely distributed. In the special cases of a reactor fire, the radioactivity emission also occurs together with the fire development.

It is generally known that there is no possibility of a short-term exit from the use of nuclear energy, so that for the foreseeable future there is only the possibility of increasing the reactor safety. The present invention provides a possibility of producing active mists with low levels of both normal operation Quantities as well as large quantities of radioactive materials occurring in the event of a disaster within a narrow radius of 600 to 1,000 m of the reactor and to be precipitated. Here, the method can even be used as an aid to extinguishing a reactor fire in view of the fact that the same way as in the case of the flue gas cleaning described xer controlled water or. The reaction solution is sprayed as a mist over and around the react and, after absorption of the radioactive carrier material in the manner described, the loaded mist will be knocked down with mist dissolving agent.

The precipitation takes place expediently in the area of low air speed, ie just above and around the (catastrophe) reactor, so that the inevitable soil contamination is also restricted to the reactor in a narrow area. Since the materials used have a high temperature resistance - calcium hydroxide, for example, decomposes only at about 580 ° C, that is, only in a possible fire flame does the temperature drop over the source of the fire. After the hydroxides also have a high water absorption capacity, large quantities of the water occurring as a combustion product are returned to the source of the fire as extinguishing water

In a corresponding manner, the invention enables use in forest fire areas. It is evident that the atmosphere over forest fire areas due to the moisture contained in the biomass in connection with the water generated by the combustion of the hydrogen of the biomass has such a high water load that already in a zo of about 30 to 50 m above the flame cone the cooling that occurs at this height is caused by fog. The ^' suppression of the mist formed in the sense of the present invention brings large amounts of water back into the source of the fire, which can make an essential contribution to extinguishing the fire. In this sense, the absorption and precipitation of contaminants can be carried out with the aid of remote-controlled vehicles and / or air-moving vehicles over catastrophe areas, for example over fire or reactor disaster sources, the fog forming by cooling with water-absorbing mist-dissolving agents absorbing water as a carrier material is struck down. Ground carbide, calcium or magnesium oxide is expediently used as a fog-dissolving agent, individually or in mixtures in an amount such that between 1/3 and 3/4 of the fog-water content is chemically bound. The mist is deposited at a height v between 30 and 50 m above the flame cone. The invention is explained below by way of example with reference to the accompanying drawing. Show it

Fig. 1 is a schematic representation of a reaction tower for flue gas cleaning in two-stage operation

Fig. 2 is a graphical representation of the dependencies between the diameter of the reaction tower and gas throughput

Fig. 3 is a schematic representation of a Rohrwendelreinigungsan location

4 is a top view of FIG. 3

Fig. 5 is a schematic representation of a Rohrbündelreinigungsan location

6 is a top view of FIG. 5

7 shows the schematic representation of a device for suppressing radioactive fallout in the area of a defective nuclear reactor

In a hard coal-fired power plant with an output of 700 MW, about 250 t of hard coal are burned per hour, with approx. 2,500,000 m ^{3 of} smoke with an oxygen content of approx. 6 to 10% per hour being generated. The temperature in the last area of the boiler (water preheater economizer) b is between 300 ° and 350 ° C and drops to around 120 ° to 160 ° C in the air preheater. The dust load is around 300 g / Nm ³ . The concentration of sulfur oxides, chlorine and hydrogen fluoride depends on the quality of the fuel. When using hard coal with a sulfur content of 1% by weight, there is an S02 content in the flue gas between 1900 and 2000 mg S02 / Nm ³ . The nitrogen oxide content in the flue gas that is not dependent on the nitrogen content of the feed material can be limited to values below 800 mg N02 / Nm ^{3 by the} primary measure.

Assuming a total reaction time of 30 minutes (1800 s), determined according to thermodynamic-kinetic calculations, at an acidic off-pressure of about 0.1 bar for the two-stage oxidation, absorption, re-reaction and precipitation of the oxidized sulfur dioxide and nitrogen oxide impurities all the way up to If the pollutant concentration limits zero emissions, the flow velocity is 0.1 m / s in the natural draft reaction tower, a necessary height of 180 m and taking into account the gas volume of 2,500,000 m ³ per hour (corresponding to 1,200,000 m ³ / 30 min) the base of the reaction tower with approx. 7000 m ³ , corresponding to the diameter of the (round) reaction tower with approx. 106 m.

The used plant shown in the drawing for two-stage operation consists of the flue gas cooler 1, the Nebelverdün stungskammer 2 and the actual reaction tower with the inner reactor core 3 and the outer reactor jacket 4, being in the case of a single-stage operation, in which The result is a mixture of nitrate and sulfate salts, a one-piece reaction tower (without a separate reactor jacket) is also possible. The reactor also contains a reservoir for liquid reaction products (Glauber's salt), a reservoir 6 for sludge-like reaction products, a manifold manifold 7, a separator 8, a clean gas discharge lock 9, another mist evaporation chamber 10 and finally a fog-dissolving zone 11. Here, the separator 8 has such a position within the tower that there is a through-flow and reaction time of about 5 minutes for reaching the separator, which results in the oxidation of the sulfur dioxide and sulfur trioxide Solution and re-reaction in the fog phase is required.

The gas to be cleaned first enters the cooler 1, in which it is cooled down to a temperature of about 60 ° C., with sodium hydroxide solution being sprayed in a stoichiometric amount to suppress HC1 and HF contamination. The condensate droplets that form are precipitated and the condensate is removed. The gas then enters the mist evaporation chamber 2, in which water. an approximately 10- b 50% metal hydroxide solution or ammonia or ammonia water is sprayed into an amount such that there is a water supersaturation of the gas between 102.5 and 105% relative humidity. The gas so cloudy then enters the first oxidation zone of the reactor interior 3 below the separator 8, in which the oxidation of the sulfur dioxide contained in the gas to the sulfur trioxide and its solution, the mist droplets and, if appropriate, re-reaction with them metal hydroxide or ammonia. The process is completed after the gas has risen to the area of the separator 8, where the mist is deposited in the end product and the collecting basin 5 collects. After passing the separator 8, the gas enters the second oxidation zone, in which 10 water, ammonia, ammonia water or firstly by means of the second mist evaporation device. an approximately 10 to 30% metal hydroxide solution is also sprayed into the gas until the supersaturation is between 102.5 to 105% relative atmospheric humidity. The reaction time in this zone is about 20 minutes, during which time the nitrogen monoxide contained in the gas is oxidized to nitrous oxide and nitrogen dioxide and dissolved in the mist droplets to nitric acid and reacted to nitrate. The mist is deposited in a corresponding manner by means of the mist pick-up device in such a way that the precipitate formed, together with the flue gas, reaches the reactor jacket. The flue gas leaves the reactor with a degree of purification v of almost 99% via the clean gas discharge lock 9, while the precipitate in the reactor jacket 4 is separated from the precipitate of the first stage and collects in the sludge collecting tank 6.

The diagram reproduced in FIG. 2 shows the dependence of the reactor diameter on the gas quantity passed and the predetermined flow rate due to the chemical conditions, based on a flow time of 30 minutes (1800 s). The diagram shows that b a gas flow rate of 2 × 10 ³ Nm ³ per hour and a flow rate of 0.001 m / s the reaction tower at a height of 1.8 m must have a diameter of 12 m, while a flow rate is the basis of 0.01 m / s under otherwise identical conditions, a reaction tower with a height of 18 m and a diameter of approximately 8.60 must be provided. In contrast, the tube coil reactor shown schematically in FIGS. 3 and 4 for small throughputs consists of a tube coil 13 arranged in a housing 12, which has an outer gas inlet 14 and an inner outlet opening into a vertical shaft 15. The active mist is brought into the gas in a spray chamber (not shown) before it enters the coiled tubing, which has a length sufficient to guarantee the reaction time. After the gas enters the vertical shaft, the mist is deposited, whereby the reaction products collect you in a sump below the shaft and can be removed there for further processing.

Correspondingly, the tube reactor shown schematically in FIGS. 5 and 6 consists of a number arranged in a housing 16 ve tical shafts 17, which are alternately connected at their upper and lower ends, that an overall continuous flow channel is formed, which at its one End has an inlet 18 and an outlet 19 at its other end. The active gas is also introduced into the gas before it enters the tube bundle, which overall has a sufficient length to ensure the reaction time. The mist is deposited in the last of the (rising) pipe sections, whereby the reaction products collect in the sump below this pipe section and can be drawn off there for further processing.

7 shows a schematic representation of an arrangement for suppressing the radioactive fall-out from a defective nuclear reactor 21 shown with fire development. In such a case, the center of a remote-controlled vehicle 22 or helicopter water or. Reg solution for generating active fog and by means of another remote-controlled vehicle 23 respectively. Helicopter fog deposit means brought the disaster focus. With the help of the vehicle, an overlying active mist cloud 24 can be generated just above the nuclear reactor, ie at a height of about 15 to above the fire cone, which reaches at least 50 to 80 m high and projects over the reactor at least 25 m on all sides. Such a fog field can have an expansion of approximately 100 mx 100 mx 80 m, corresponding to a volume of 800,000. By means of sensors arranged within the fog field, the breakthrough of the radioactivity to the outside of the fog field can be determined, in which case the precipitation of the fog immediately follows in such a way that fog-dissolving agent is sprayed into the wol from above. To prevent the outflow of radioactivity wi the process of fog formation and fog dissolution expediently repeated in time intervals, which can be half or one hour depending on the situation, the renewed fog formation already immediately following the fog dissolving from above in height zones of 5 - 10 me Mist dissolver is finely ground lime or magnesium oxide or carbide with or without boron, the precipitation of which gradually forms an insulating layer over the stove. To further limit the spread of the radiating material, the catastrophe area can be enclosed by means of film walls, the middle fess Elballon brought to the appropriate height and held there.

Claims

Claims 1. Process for the simultaneous cleaning (zero emission) of industrial smoke, combustion gases from internal combustion engines, natural fires, radioactive emissions from nuclear reactor disasters or the like. Gasför gene media from their dusty and - optionally radioactive gaseous contaminants, characterized in that after cooling to a temperature between 20 ° and 60 ° C as well as removal of the halogen impurities in the gas by spraying water with a particle size of less than 25 μm, artificial fog and the gas during a sufficient time to dissolve and re-react the pollutants in the mist droplets in a clouded mist State is maintained, whereupon the saturated mist droplets are deposited with the aid of a mist-dissolving agent sprayed into the gas stream in finely divided form. 2. The method according to claim 1, characterized in that for the formation of (active) mist an aqueous solution of a reagent with the dissolved luftoxidie th pollutant constituents, water-soluble reaons forming reagent, preferably a metal hydroxide, ammonia and / or ammonia water in the Gas is sprayed. 3. The method according to claim 1 or 2, characterized in that to remove the hydrogen halide impurities (HF, HCl) during de condensate separation (in the cooling stage) in the cooling gas stream from sodium, potassium or magnesium hydroxide as 10-50% -ige, preferably before 30 - 45% solution in - based on the amount of halogenated hydrocarbon contained in the gas - three to four times over-stoichiometric amount is used. 4. The method according to claim 1 or 2, characterized in that al 10 with the dissolved oxidized sulfur and nitrogen pollutant constituents chemically reacting material ammonia or ammonia water, sodium potassium or magnesium hydroxide as 10 - 50%, preferably 30 - 45% solution in - based on that contained in the gas Total amount of pollutants at least stoichiometric amount is used. i_ 5. The method according to claim 4, characterized in that when ammonia or ammonia water is used, the chemically reacting material ammonia to a proportion of at most 98%, preferably between 85 and 95%, but otherwise sodium, based on the stoichiometric amount. Contains 20 potassium or magnesium hydroxide. 6. The method according to any one of claims 1 to 5, characterized in that the exhaust gas to be cleaned is set to an oxygen partial pressure of at least 0.1 bar. 7. The method according to any one of claims 1 to 6, characterized that the active mist is formed by injecting the liquid with the aid of air-assisted atomizing nozzles. 8. The method according to any one of claims 1 to 6, characterized in that the liquid is injected under pressure with pure oxygen 9. The method according to any one of claims 1 to 8, characterized in that the addition of the aqueous solution takes place in two stages such that an approximately 50% active agent solution in a first stage and after a re tion time of between 3 and 10 minutes to the solution and re-reacting oxidized sulfur dioxide impurities in a second stage 30% active agent solution are added for the purpose of the solution and »Reaction of the oxidized nitrogen oxide impurities during a reaction time of between 15 and 25 minutes. 10. The method according to claim 9, characterized in that, depending on the speed of the concentration of sulfur dioxide in the exhaust gas, the first reaction stage is repeated several times such that about 1,500 mg of sulfur dioxide per m ^{3 of} exhaust gas this absorption stage is carried out once. 11. The method according to claim 8 or 10, characterized in that reaction products obtained from SO 2 in the first absorption stage are separated from the reaction products obtained from NOx in the second reaction stage. 12. The method according to claim 11, characterized in that at one of sodium hydroxide as the reaction liquid, the purification of the exhaust gas b is carried out at a temperature of above 32.4 ° C., preferably at 45 ° to 50 ° C. 13. The method according to claim 11 or 12, characterized in that d occurring sodium sulfate solution gassed with hydrogen sulfide and the g formed heavy metal sulfides agglomerated by thermal treatment and then filtered off. 0 14. The method according to claim 12, characterized in that for low impact of the absorbed in the first stage, oxidized as sodium sodium S02 component 5 - 15%, advantageously 8 - 12% anhydrous N trium sulfate and sprayed the precipitated sulfate with warm water an external source is hydrated up to sodium sulfate decahydrate. 5 15. The method according to any one of claims 1 to 14, characterized in that the spraying of the liquid up to a supersaturation of the air v is at most 105%, preferably between 102.5 to 104.5% relative humidity. 0 16. The method according to any one of claims 1 to 15, characterized gekennzeic net that the gas to be cleaned is enriched with the help of exhaust steam, for example, a power plant with moisture up to close to the saturation limit ang. _ 17. The method according to any one of claims 1 to 16, characterized gekennzeic net that the droplet formation is supported by spraying condensation nuclei on the gas cooled below the dew point tap. 18. The method according to claim 17, characterized in that dust is used as condensation germs from the reduced-power elect filter. 19. The method according to any one of claims 1 to 18, characterized in that the precipitation of the mist droplets with a metal carb, for example calcium, magnesium, aluminum or manganese carbide, or the corresponding metal oxides. Metal hydroxides, further -hydr bil'denden substances, such as phosphates, preferably disodium ronohydrog phosphate, sodium sulfate or carbonate individually or in a mixture with one in an amount between 1 and 5.5 g of active material per cubic meter of fog air. Fog gas occurs. 20. The method according to claim 19, characterized in that the nebulizing agent is used in an amount which is 5-15% lower than the amount necessary for complete binding of the water content of the active mist droplets. 21. The method according to any one of claims 1 to 20, characterized in that the bezw contained in the precipitate. in the second Nebelau solution stage, nitrate is reacted with ammonium chloride or ammonium hydrocarbonate to ammonium nitrate. 22. The method according to any one of claims 1 to 20, characterized gekennzeic net that the nitrate accumulation from the second active mist dissolving stage is worked up to the N02 rich gas. 23. The method according to any one of claims I to 20, characterized in that the bezw contained in the precipitate. The magnesium sulfate obtained in the first Nebelau solution stage is processed by thermal decomposition and washing with sodium sulfite as well as thermal decomposition of the sodium hydrosulfite formed in the process to give rich sulfur dioxide gas. 10 24. The method according to any one of claims 1 to ^'23, characterized gekennzeichne that the condensation and deposition of impurities with Hil is from facilities in which the gas zel- means in horizontal egg or double windings arranged elastic or metallic Le ⁱ⁵ obligations BEZW. pipes laid in vertical loops for the purpose of chemical reaction, mist formation and precipitation. 25. The method according to claim 22, characterized in that the Akti mist generation, absorption of impurities and precipitation v ^* - ^υ loaded active mist is carried out with the help of (rebuilt) natural train reaction tower, which have multi-stage built-in active mist generation and precipitation devices. 26. The method according to any one of claims 1 to 23, characterized gekenπzeic ^* --- 'net that the absorption and precipitation of contaminants with the help of remote-controlled ground and / or air-moving vehicles via Cat Verse areas, for example, about fire or nuclear reactor disasters. 27. The method according to claim 26, characterized in that at one in catatrophic incidents associated with the formation of high humidity v combustion, for example forest fires which are formed by cooling mist with water chemically reacting and water absorbing mist-dissolving agents and knocked down on them Large amounts of moisture can be returned to the source of the fire as an extinguishing agent. 28. The method according to claim 25 or 27, characterized in that a mist dissolver, ground carbide, lime or magnesium oxide are used singly or in mixtures in such a way that approximately between 1/3 and 3 of the mist water content is chemically bound. 29. The method according to any one of claims 25 to 28, characterized in that the fog is deposited at a height of between 30 and 50 above the flame cone. 30. The method according to any one of claims 25 to 29, characterized gekennzeic net that the disaster area of a defective radioactivity-eliminating nuclear reactor is delimited by means of a foil wa held by captive balloons.