DE1467005C

DE1467005C - Process for reprocessing the scrubbing solutions resulting from the ammonia scrubbing of the tail gas from sulfuric acid contact systems

Info

Publication number: DE1467005C
Authority: DE
Inventors: Herbert 5022 Junkersdorf Furkert
Original assignee: Cheraiebau Dr. A.Zieren GmbH & Co KG, 5000 Köln

Claims

1 2 '■

The invention relates to a method for processing the ammonium sulfate-containing solution besei-

tion of the ammonia scrubbing of the tail gas from Tigt. At the same time it succeeds according to the invention

Sulfuric acid contact systems incurred, in the white process, through the utilization of the sulfur

essential ammonium sulfite and ammonium sulfate content of the washing solution for acid production

containing washing solutions. S the yield of sulfuric acid to diaht to the

It is known to increase the tail gas by sulfuric acid- theoretical value. A wash contact systems in sprinkled towers. ■!
and the washing solution continuously ammonia and exemplary embodiment , \
Add water. An aqueous solution is obtained in this way. The exhaust gas from the H ₂ SOj condenser contains a pulse which, in addition to other ammonium salts, contains ammonium sulfate and ammonium sulfate in succession. Washing towers have been run in their fluid circuits. these solutions have so far either been discarded or fed in with aqueous ammonia solution. A solution is withdrawn from the sulfuric acid while recovering part of the sump of the washing towers, sulfur dioxide in an ammonium sulfate solution over the 11.48 percent by weight (NHJ ₂ SO ₄ , 18.53. According to another method, the 15 percent by weight (NH ₄ ) ₂ SO, and 14.1 percent by weight of solution oxidized with air under pressure, whereby one contains (NH ₄ ) HSO _3. This used washing also receives ammonium sulfate.This process solution has a density of 1.24 and a pH value has the disadvantage That the ammonium sulfate today is from 6.5. The SO ₂ content of the exhaust gas is difficult to settle. From the German scrubbing from about 0.2 percent by volume to 0.01, volume patent specification 861551 is the breakdown of waste - ao percent reduced. '
sulfuric acids at temperatures above 1000 ° C. The washing solution is known to _{produce SO 2.} In the Swiss patent 297 827 serving sulfur combustion furnace supplied. It describes the cleavage of denitrated waste sulfuric acid when burning 11 sulfur 153 kg or a solution containing decomposable sulphates in the combustion chamber of the furnace. This cleavage takes place in a vortex nozzle. This amount of solution contains about 17 kg layer roasting oven with almost no oxygen excess. Sulfur and about 12.1 kg of nitrogen in the form of the

In the cleavage of solutions containing ammonium salts, called ammonium salts. In the incineration

there is a risk that if the oxygen space in the furnace is too small, the temperature will be around 1100 ° C

content of the gas, some of the ammonia is not oxy- and the oxygen concentration is about 7.5 volume per-

is dated, while with too strongly oxidizing conditions 30 cent. Under these conditions the ammo

combustion to nitrogen oxides takes place. In nium salts essentially to SO ₂ , N ₂ and H ₂ O

Both cases contain the catalyzed SO _s -containing columns.

Gases nitrogen oxides, which are a contamination of the produc- The yield of sulfuric acid is increased by

cause sulfuric acid. the co-incineration of the washing solution of 98.1

It has now been found that in the Ammo 35 99.8%. The nitrogen content of the scrubbing solution generated by the scrubbing solution produced by 'S-Verniak scrubbing of the end gas from sulfuric acid contact combustion and the cleavage of the scrubbing solution and the sulfuric acid produced is 4 - 10 ^-1 , the sulfur dioxide formed for the sulfuric acid weight percent N (4 ppm). In the case of quantitative oxidation, production can be made usable without the ammonium used in the S-combustion at temperatures above 850 ° C and at 0.4 percent by weight N (4000 ppm) to be expected.

9 percent by volume into the grate, incineration or patent claim cracking furnace, in which the SO ₂ -containing gas is generated 45

will. In this way, from the process for working up the am-

needed scrubbing solution sulfur dioxide, nitrogen moniak scrubbing of the end gas of. Sulfuric acid-

and water vapor. Although, as is well known, in the contact systems incurred, essentially am-

Combustion of hydrogen sulfide containing nitrogen oxides, bil- monium sulfite and ammonium sulfate

if this is gaseous ammonia or cyan 50 washing solutions, marked by

contains hydrogen, the nitrogen oxide content remains the net that the washing solution is at

acid produced less than 5 mg nitrogen per ren above 850 ° C and if a

Kilograms of acid. Oxygen excess of 3 to 9 percent by volume

The invention eliminates a major disadvantage in grate, incineration or cracking furnaces.

the end gas scrubbing with ammonia, namely the atomizer, in which the SOj-containing gas is generated.