DE2045323B2 - Process for removing ammonia contained in coke oven gases - Google Patents

Description

The invention relates to a method for producing a steam at about 98 ° C. with the removal of water contained in coke oven gases with a steam: ammonia ratio of about 7: 1. Water washed-out ammonia (NH ₃ ), which is made up of In order to reduce the water content, the washing water is generally driven off and the swaths are cooled to about 65 ° C, so that over as ammonia swaths, which are now a water vapor in several ways: Ammonia ratio enriched cooling stages and then present with the addition of 0.3 to 0.35: 1. Since such plumes of air do not burn themselves to decompose the ammonia in nitrogen 40, considerable (N ₂ ) and water vapor (H ₂ O) will in any case be burned in a furnace or borrowed amount of foreign high-grade fuel gas in a combustion chamber. to clear the plumes for the ammonia

In most coking plants, the temperature required for combustion was around 800 ° C the dry distillation of the coal inevitably bring.

accumulating ammonia is removed from the gas and to 45 If a non-deacidified vapor is burned, salable products such as ammonium salts or the amount of fuel gas is reduced by the strong water processed. Since the economic heating conditions introduced by the hydrogen sulphide (H ₂ S) for these sales products have changed in value, but then for a considerable period of time, one goes over to the ammonia more and more of the atmosphere due to the exhaust gas destroyed 50 discharged sulfur dioxide,
ten. In the present invention, technical

The previously known ammonia destruction deacidified ammonia plumes started, i.e. There are essentially two processes involved in the processing of ammonia-containing water Groups, according to the one group Am- the acidic constituents have already been separated off moniak first in its components nitrogen 55 and for the production of sulfuric acid or elementary and hydrogen is decomposed and the hydrogen of this tarem sulfur is used.

Mixture is then incinerated, while the object of the invention is that in the Ammoman according to the other group the ammonia immediately contained ammonia vapor at the slightest partially oxidized or burned, with nitrogen and technical effort with a self-sufficient combustion steam develop. Destroy the proceedings of the last 60 process.

Group differ in the way that it is suggested that one (except for one

and where the ammonia plumes are burned. ignitable concentrate of enriched) ammonia

The first group includes, for example, the ammonia ratio of 0.15 to 0.2: 1 treated in the steam: Ammodeutschen patent specification 1202772, after which the ammonia vapors of the ammonia water reduced into the hot gas flow ammonia steam by burning a lower concentration as well as air fractions preheated in the stoichiome heating medium then introduced in a decomposition-tric quantity. In this way zone can be decomposed _{into N 2} + H _2. Then, by regulating the supply accordingly,

3 4

Flow rates of highly concentrated and less water vapor: ammonia ratio of less than

strongly concentrated ammonia vapor streams a 0.2: 1 and a corresponding temperature of

self-sustaining combustion process 55 ° C to the burner 6 of a combustion chamber 7. In the

achieve for example in a combustion chamber. Here burner 6 also opens a line 8 through which

at is so to speak the heat of combustion of the high 5 an air flow is supplied, whose for a disruptive

Enriched vapor flow is used to achieve the flow rate required for less chiometric combustion

ger concentrated vapor streams directly on the controlled by a controller 9 depending on the Am-

To heat up the combustion temperature. If the vermonia vapor flow in line 2 is being regulated,

Increase in the combustion process in the combustion chamber The ammonia vapor / air mixture ignites

Temperature, then either the inflow of the io is sent to an ignition device of the burner 6 and

strongly concentrated vapor choked or that burns, forming a long flame in the

Increased flow of weakly concentrated swaths. Combustion chamber 7. The exhaust gases leave the combustion

The procedure is reversed when the combustion chamber is connected by a line 10.

temperature shows a downward trend. The self-sufficient, approximately in the longitudinal center of the combustion chamber 7

Combustion that takes place without foreign gas establishes a line 11 through which a small amount of ammonia

once there is a saving in operating costs. Furthermore, a mixture of air and earth occurs. This mixed flow

give due to the lower to be enforced is branched off in front of the cooler 4,

Gas quantities lower investment costs because the vapor flow carried away through the line 12

Dimensions of apparatus and devices of lower concentration and of one by the

can be smaller. 20 line 13 formed incoming air flow, whose

If there are corresponding operating conditions on co-inflow, a control device 14 depending on the farm, one can in the hot vapor flow of the line 12 on the basis of the disturbance gas flow, which is dosed by the combustion of ignitable chiometric proportions,
according to ammonia vapor concentrate is generated. Another regulating device 15 controls the flow ammonia vapor of various concentration quantities of the vapor stages flowing through line 12 as well as introducing the corresponding air fractions in a regulating flow of lower concentration in dependent quantities. The vapor streams of the temperature of the individual concentration levels through the line 10 are
3 ° from the individual cooling stages, in which the ammonia main stream is enriched as follows: The concentration of the main steam stream flowing through line 2 and with the required proportion of air at various points in the combustion chamber is between the burner mouths chosen so large that introduced by the digestion and waste gas discharge. combustion in the combustion chamber 7 becomes free

Another feature of the invention consists in the heat of reaction flowing in through line 11

that the supply of ammonia fumes from the endless less concentrated fume air mixture

The final concentration is based on the temperature required for combustion

and the associated air content is heated depending on 800 ° C.

speed of the combustion process in the combustion chamber- To ensure that the combustion reaction

can be controlled automatically. This is what is maintained in the combustion chamber 7

Sequence of the combustion process regardless of 40 the added amount of the vapor flow is lower

Operating personnel. Concentration of the line 12 with hooves of the outflow

One embodiment of the new method is the temperature of the exhaust gas from the combustion chamber 7 cleaned shown schematically in the drawing and based on it. When the temperature drops, the explained standing. Steam volume 12 throttled, thereby falling

The 45 highly concentrated ammonia vapor 2 leaves the driver 1 through line 2 A stream of ammonia vapor pervades the table in larger quantities, so that the tempera cooling stages 3 to 5 and is maintained in the combustion chamber with a molar level of rotation.

1 sheet of drawings

Claims (3)

1 2 follows the final combustion of the gas mixture claims: 11 ^ t air. The disadvantage of this process is that it requires preheating of the ammonia vapor 1. Method of eliminating in coke oven by means of an extraneous gas stream, what the cost gases contained in the process, which is washed out with water, increases considerably. Ammonia (NH ₃ ), which is removed from the washing water. The second group can be, for example, the is driven and assign the aborter as ammonia German patent specification 1 200 268, which pre-swath leaves, which beats in several cooling stages, which enriched in the indirect ammonia and with the addition of air in a voltage process at any point, from Oven or a combustion chamber are burned, io hydrogen sulfide largely free ammonia as a result characterized that an am- a desorption process with ammonia-free monia vapor stream with a steam underfiring gases and / or steam to un-ammonia ratio discard from 0.15 to 0.2 to 1 and then discard those loaded with ammonia is burned and in the hot gas stream Ammo vapor in the heating flues of coke ovens to vernia vapor lower concentration as well as 15 burn. Here, too, is a foreign gas in the form of Air fractions in stoichiometric amounts - underfiring gas for the combustion of the ammonia leads to be. necessary. This foreign gas can simultaneously exhaust 2. The method according to claim 1, characterized in that the propellant is in the ammonia expeller. Is used to indicate that as in the hot gas stream with steam as the stripping agent, then the ammodes corresponding air proportions to be introduced 20 nia plumes after driving the underfire ammonia plumes those of different rungsgas added. Concentration level in controllable quantities. be turned. to a foreign gas is problematic in that 3. The method according to claim 1 and 2, characterized in the cooling during transport ammo, that the supply of the hot 25 niakhaltiges condensate fails, resulting in the Schwie gas flow with the corresponding air proportions leads to the ammonia from the ammonia vapor to be introduced is removed in dependent coke oven gas. ability of the combustion process in the furnace contains auto- ammonia-containing water on coking plants is controlled automatically. in addition, hydrogen sulfide and carbon dioxide 30 oxide. The ammonia water can be used before the abortion of the ammonia freed from the acidic components so that the aborter leave technically deacidified plumes. When driving off the water