DE3006198A1 - Removing contaminants from combustion plant fumes - by reacting sulphur cpds. with liq. ammonia - Google Patents

Abstract

Atmospherically harmful components such as sulphur cpds., nitrogen cpds., F and Cl in the fumes from industrial combustion plant are removed by intermittently spraying jets of liq. NH3 into the departing fumes. The NH3 concn. can be adjusted to varying S contents in fuel and treated minerals, as may be the duration and/or frequency of the individual impulses. Provided they do not react with NH3, further reagents may be injected simultaneously to deal with other contaminants. The spray equipment may be combined with a heat exchanger for recovering waste heat from the fumes, with a shape corresp. to the fume outlet. Used for combustion plant in power stations, casting shops, brickworks etc. The resulting prod. is useful as a fertiliser and does not involve the filtering and disposal problems arising with the known lime-dust treatment of fumes.

Description

Process for the elimination of the polluting, in smoke

gassing of all kinds of sulfur compounds from combustion systems in the form of SO, or SO, The invention relates to a process for the elimination of polluting gases in combustion systems of all kinds, for example power plants, foundries or the like, accruing Sulfur compounds in the form of SQ2 and 503, respectively.

The sulfur compounds carried along in the flue gases carry if they are released into the open with the smoke gases, to a very large extent contribute to air pollution and thus represent a significant adverse environmental impact They lead, especially in industrial metropolitan areas, to the dreaded so-called "smog", which sets off an alarm when a certain concentration is reached triggers and makes defense measures necessary.

To harm the sulfur compounds produced with the flue gases to make it is known to release lime dust into the smoke gases released into the open air Lines, for example in a chimney, to be blown, whereby by reaction the sulfur compound with the lime dust gypsum (CaS04) is formed. This plaster of paris must be filtered out of the flue gases, since he too otherwise an undesirable one and is harmful to the environment. Also, this is a well-known method cumbersome and time-consuming, once because of the necessary provision of the lime dust, but above all because the gypsum obtained is seldom in its accumulating amount is usable, so that it is to a large extent undesirable Waste must be treated and disposed of, which is another additional expense connected is.

In contrast, the invention is based on the object of a method to create, on the one hand, a satisfactory elimination of the sulfur compounds enables, and in which a product is achieved in a simpler and more convenient way, that can be put to beneficial use without difficulty.

This object is achieved according to the invention in that the Pipe discharging flue gases into the open, for example into a chimney, liquid, in its concentration, if necessary by dilution with water to the sulfur content the flue gases adapted ammonia is blown.

The ammonia is readily available in the required quantities available and easy to transport, and when reacting with the Sulfur compounds in the flue gases are obtained in powder form ammonium sulphate, which is used as Fertilizers are also put to beneficial use without difficulty can be. In rural areas with extensive population, where arable farming was carried out the ammonium sulphate released with the flue gases falls to the ground and serves fertilization without further measures being necessary. In densely populated areas However, it is recommended to separate the ammonium sulphate from the flue gases by filtering, it can be used as a fertilizer without further treatment.

The features of the subclaims serve to develop the method according to the main claim.

The intermittent pulse injection of the is particularly advantageous high pressure ammonia.

This creates an intensive vortex and thus the greatest possible Contact with the sulfur solutions of the flue gases and the ammonia is ensured with the consequence that an optimal reaction occurs to the formation of dusty Ammonium sulfate. It is useful in this case, the ilisen over the length of the smoke gases leading line to distribute, with the times of the pulse inputs of the ammonia can be different for the individual nozzles. Also a comprehensive transfer university the nozzles appears to be advantageous in the interest of an optimal swirling of the flue gases. Another significant advantage is given by the fact that during the injection of the Ammonia adjusts the amount of ammonia to the different sulfur content the flue gases is possible because both the pressure and the pulse sequence and the pulse frequency can be varied in many large-scale processes is usually the sulfur concentration of the flue gases and also the shape of the Sulfur gas be constant. In the case of processes, however, where due to different Characteristics of the coal or the minerals to be thermally treated with large Fluctuations in the amount of sulfur, for example in the case of coal or coal containing pyrite Pvrt-containing clays, to be expected, will benefit from this possibility of variation The ammonia must be used to add the ammonia by dilution or change the pressure, the pulse duration and the pulse train optimally to the respective The sulfur content of the flue gases varies in size and during operation can also be subject to different fluctuations.

To be able to do this, it is beneficial to do before and after a pulse point at the outlet in the line discharging the flue gases to the outside continuously or intermittently to measure the sulfur content of the flue gases in order to depend to be able to control the amount of ammonia to be sprayed from the measurement result. These Control can be carried out by a device evaluating the respective measured value, by automatically adjusting the dilution, the pressure, the pulse duration and the pulse frequency individually or optionally at the same time varied so that the flue gas practically leaves the line free of sulfur compounds. In this way it is possible the flue gases practically completely removed from the sulfur compounds before they enter the open air to free.

The method according to the invention also enables inferior ones to be used cheaper fuels, which are often found in the flue gases because of their high levels Sulfur content is prohibited. For example, heavy oil can be used as a fuel are used, the use of which is in the interest of the Environmental protection mostly so far has had to do without.

The method according to the invention can also be used in Any large-scale chemical and metallurgical engineering processes in which sulfur in the form of SO and / or S03.

With formation of a high, polluting the environment by sulfur compounds Atmosphere, for example with the formation of a smog, it is also possible to use the ammonia to add to the smoke gases released into the open, for example by raining from an airplane.

Claims (7)

CLAIMS 1. Process for the elimination of environmentally harmful, in flue gases from all types of combustion systems, for example power plants, foundries or the like, resulting sulfur compounds in the form of SO, respectively So3, d a d u r c h e -k e n n n z e i c h n e t, that in the the smoke gases into the open discharging pipe, for example into a chimney, liquid, in its concentration if necessary, adapted to the sulfur content of the flue gases by dilution with water Ammonia is blown in. i. Method according to claim 1, characterized in that the ammonia through nozzles in intermittent pulses under one, a strong fogging of the Flue gas generating pressure is blown. 3. The method according to claim 1 and 2, characterized in that the Ammonia through several spaced apart over the length of the flue gas pipe, if necessary, nozzles offset from one another in the circumferential direction are blown in 4th Method according to claim 1 to 3, characterized in that the ammonia with different Press is blown. 5. The method according to claim 1 to 3, characterized in that the Ammonia is blown in with different pulse duration. 6. The method according to claim 1 to 3, characterized in that the Ammonia. is blown in with a different impulse frequency. 7. The method according to claim 1 to 6, characterized in that before and after a pulse point the sulfur content of the flue gases intermittently or is measured continuously, and that the dilution and / or the pressure and / or the pulse duration and / or the pulse frequency can be controlled by the measured values.