DE1808710C3 - Apparatus for the production of carbon disulfide and an aqueous alkali metal hydrogen sulfide solution from a gas obtained in the manufacture of synthetic fibers - Google Patents

Description

3 4

fid concentration in the gas absorption solution are very, removed by spraying water and the small. Furthermore, the gas absorption solution contains resulting washing absorption solution that cleans out, E.g. Glauber's salt, which is a product made of sulfuric acid, Glauber's salt and other associations Reaction with the sulfuric acid contained in the gas contains impurities, run through line 17 spirit. It was therefore impossible to leave sodium hydrogen sulfide 5, so that Glauber's salt and other contaminants could become contaminated The desired concentration and amount cannot be formed in a gas absorption solution in the AbReinheit from a gas absorption solution with economic section 16, where the aqueous alkali solution is slightly Gain advantage. solution is sprayed. Reference numbers 2 and 3 are the subject matter The invention is a device draw a feed water or a waste water. to water sprayed one after the other in the supply line is preferably warm. When and by blocking separate zones with gas supply lines against the gas with an aqueous sodium arsenite solution and sprayers for water and zones washing and cleaning is the use of with spraying devices for alkali hydroxide solutions warm water is particularly preferred in order to prevent a derivation leading from the zone for the arsenic sulfide in a washing and cleaning washing absorption solution and one from the zone 15 supply apparatus 10 as a result of the temperature reducing Derivation for alkali hydrogen sulfide solution with ration fails and settles. It is economical downstream washing zone and adsorption column. as warm water, a radiator wastewater from a

According to the invention it is possible to use a good steamer for recovery of an acid from a

Purity to use an aqueous solution of an alkali hydrogen viscose coagulating solution. The other

sulfide of the desired concentration and amount from 20 amount of hot water supplied 2 is expediently

of the gas-absorbing caustic alkali solution in the presumably about 3000 liters / hour, if the

to gain washing devices and at the same time acting exhaust gas volume 30,000 to 40,000 m ³ / hour

the recovery of coal disulfide is economical.

In section 16, most of the material is in the feed gas

heights. 25 contained hydrogen sulfide in the form of an alkali

According to an advantageous embodiment, the hydrogen sulfide is obtained in order to thereby

inventive device a spray head with stung in a washing and cleaning tower to yer-

branched supply lines for spray openings. diminish where a dilute aqueous solution of one

The device according to the invention uses a dehydrosulfurizing agent, and to achieve a high recovery efficiency with regard to and purification stage with a spray of carbon disulfide of the collected gas during the transport to the scrubbing. The temperature water and a spray of an aqueous caustic alkali solution to be used alkali washing solution is brought into contact as solution in such a way that none occurs when washing with water preferably higher than mixing and the gas is prewashed room temperature. Your concentration is will. In this case, an aqueous Natriumhydrogensul- 35 is usually 0.5 to 2.0 ° / o of alihydrogensulfid caustic and 5 to fidlösung from the resulting Ätzalkali- 20 ⁰ Zo to Alk. In the section 16, gas absorption solution can be obtained and the pre-watered an aqueous alkali hydrogen sulfide solution 5 can be subjected to the gas scrubbing and cleaning stage and the desired concentration and amount by the variable gas adsorption stage, thereby to recover the amount and concentration of the carbon disulfide to be sprayed. In the following, the aqueous alkali solution (see table) will be used to explain the invention in more detail with reference to the drawings. The concentration of the alkali washing solution provided for the re-explained, circulation can

F i g. Fig. 1 is a simplified diagram obtained by feeding an alkali aqueous solution

Embodiment of the device according to the invention line 4 to the desired value of about 0.5

shows, and 45 to 2.0% NaOH are regulated. Furthermore, this is

F i g. 2 is a cross section along the line aa ' pressure gradient when spraying the gas in the conveying

from F i g. 1, the formation of an example of a pipe low. Accordingly, the energy cost becomes

Represents pre-washing device, with which the spray is reduced, whereby in connection with low construction

If water or an aqueous caustic alkali solution is used, the process is economically very advantageous

can be effected. 5 ° becomes. In particular, there is the advantage that in the

As shown in FIG. 1, a solution 5 becomes a solution in every viscose fiber manufacturing industry

Stage of a viscose fiber production occurring gas with absorbed gas or gas absorption solution S im

The alkali washing section 16 is guided into a conveying pipe 1 made of collecting elements directly for desulphurization

(The drawings show two groups of collection in a cleaning stage of viscose fibers

elements 12, 13, 14 and 12 ', 13', 14 ', the z. B. every 55 can be used without it being a cleaning

Part of a spinning apparatus, a coagulation bath treatment or a concentration setting

or a cleaning device). Is subject to development.

selectable points of the delivery pipe 1 are a or means 6 and 7 for spraying water and

arranged a plurality of prewash devices, which are made of an aqueous caustic alkali solution with regard to their

an element for spraying water and a shape and configuration are not particularly limited,

an element for spraying an aqueous AI, however, those with

pass potash solution. In this case the element is many branched pipes 8 and many spray openings

for spraying water arranged so that a gene 9 are provided. The objects of the invention can

collected extracted gas first on this egg- reach more smoothly! if there are several

ment and then on the element for spraying 65 monitoring devices in selectable sections of a

the alkali solution meets. In the section 15 conveyor pipe, as shown in Fig. I, are arranged

Sulfuric acid mist and other easily water-soluble are and are one of every viscose fiber production

Substances present in the collected gas streak collected gas into each of the pre-wash

directions is directed. In order to prevent the solutions occurring in the two sections 15 and 16 from mixing, a suitable dam is provided, as shown in FIG. 1 is shown, or it is the conveying tube is formed wave-shaped or accordion-like. The reference numeral 10 denotes a gas washing and cleaning apparatus. The pretreated gas is fed in from its lower section and brought into contact in countercurrent with a scrubbing liquid containing a dehydrosulfurizing agent, the liquid falling down at the top to ensure complete desulfurization. In order to operate a known tower for the adsorption of carbon disulfide, as is commonly used, with economic advantage, the hydrogen sulfide concentration in the collected gas should be limited to a value below about 0.010 g / m ³ after washing and cleaning. Reference numeral 11 denotes a carbon disulfide adsorption column which is packed with activated carbon and other adsorbents.

Embodiments of the method according to the invention are described below.

example

There were two gases (hereinafter referred to as Gas I and Gas II) from a spinning stage and a cleaning step of viscose fiber production, and a gas (hereinafter referred to as Gas III referred to) with a high hydrogen sulfide content, which from a spinning stage, a cleaning stage and an acid bath, each in a delivery pipe in an amount of 35,000 up to 40,000 mVhour. It was wastewater of 37 ° C from a cooler of an evaporator to Acid recovery from a coagulating bath at a rate of 3000 liters / hour sprayed by means of a prewash device with a nozzle head, and then an aqueous Na Trium hydroxide solution of 40 ° C by means of the atomizer of the alkali pre-wash section sprayed un in the circuit in the same way under the conditions indicated in lines B and C in Table I. guided. The concentration of sodium hydrogensul

ίο fid and the concentration of unreacted sodium hydroxide after one hour is given in de lines D and E of the table. The three gas absorption solutions were used immediately to clean and desulfurize viscose fibers. There; pre-washed gas was turned into a. Washing and cleaning tower transferred, where it was treated with a washing solution which contained sodium arsenite (As ₂ O ₃ ) with a concentration of 20 to 35 g / liter and a temperature of 43 ° C. The in

The circulating washing solution volume was 15 (up to 200 kiloliters per hour. The hydrogen sulfide content in the treated gas was, as indicated in line H of the table, almost below 0.005 g / m '.

Two gases (ΙΓ unc

as ΙΙΓ), which were collected from the same stages as Gas II and II and had about the same composition, washed with an aqueous sodium arsenite solution without being subjected to a prewash treatment. In this case, as indicated in line G of the table, a highly concentrated scrubbing solution was required in order to reduce the hydrogen sulfide concentration in the scrubbed gas to about 0.01 g / m ³ . As a result, in the case of gas ΙΙΓ, a particularly large amount of precipitation occurred in the tower, and the process had to be stopped after 20 days.

table Examples and control examples

Hydrogen sulfide concentration

in the collected gas (g / m ³ )

NaOH concentration in the prewash

solution (g / l)

Amount of supplied NaHO prewash

solution (l / h)

Amount of circulated gas absorption solution (l / h)

Sodium hydrogen sulfide concentration in

the gas absorption solution (g / l)

Concentration of unreacted NaOH

in the gas absorption solution (g / l)

Hydrogen sulfide concentration in the gas transported after the pre-wash

(g / m ")

Concentration of the sodium arsenite solution

(g / l)

Hydrogen hydrogen concentration in the gas transported after washing with sodium arsenite solution (g / m ³ )

III

ΙΙΓ

1.14

0.003

1.14
40

0.008

2.31

210

360

20,000

250

34

0.90 30 to 35

0.005

2.32

2.32 70

0 _; 012

1 sheet of drawings

Claims (2)

trium hydroxide, to be removed before the adsorption stage. However, if the hydrogen sulfide concentration 1. Device for the recovery of sulfur ion in the feed gas compared with the carbon dioxide and an aqueous alkali hydrogen 5 carbon concentration is increased, the dehysulfide solution is from one in the production of drosulfurization difficult smoothly and with high Synthetic fibers obtained in the viscose process. Efficiency using a usual Carbon disulfide and hydrogen sulfide are gas scrubbing and cleaning equipment to be maintained alone Gas, consisting of washing and supply lines. When the hydrogen sulfide concentration Sorption zones, characterized by io in a feed gas is large, the concentration must a dehydrosulphurizing agent, e.g. sodium amine, arranged one after the other in the supply line (1) and by blocking separate zones (15) with senite and sodium hydroxide, be increased to the de-gas supply lines (12, 13, 14) and spraying device hydrosulfurizing capacity of a washing liquid gen (6) for water and zones (16) with spray in- to increase. In this case, different trainings are used (7) for alkali hydroxide solutions, so 15 storage in the gas washing and cleaning apparatus a derivation door leading from the zone (15). For example, when performing (17) for washing absorption solution and one from washing with an aqueous solution of Natriunjder Zone (16) leading discharge (18) for alarsenite colloidal sulfur and an arsenic sulfide-bishydrogensulfide solution formed with downstream precipitate, and when washing with a washing zone (10) and adsorption column (11). 20 alkali various polysulphides are precipitated 2. Apparatus according to claim 1, characterized also form sulfuric acid and other components net through a spray head with branched to Glauber's salt and other compounds. Such derivatives (8) for spray openings (9). Storage is very harmful to the process, and it is often necessary to remove them while the process is being canceled. To such a To overcome the difficulty, the washing liquid This is why dehydrosulphurisation can always be present in low concentration and large quantity not yet carried out with high efficiency The invention relates to a device 30 leads. for the production of carbon disulfide and experiments have shown that, for. B. when washing aqueous alkali hydrogen sulfide solution from a carbon disulfide and sulfur sulfide degree obtained with an aqueous solution of sodium arsenite one of the production of synthetic fibers in the Viskoseverfah- complete dehydrosulfurization with high degree of confusion cannot be carried out if the hydrogen-containing gas, consisting of scrubbing 35 hydrogen sulfide concentration in a Feed and adsorption zones. gas exceeds 1.5 g / m ³ , in particular ^{2 g / m s.} It It is known that carbon disulfide by cooling is therefore difficult to purify a gas that is released from was collected with separation of the sulfur contained in a viscose coagulation bath, to liquefy hydrogen and the condensed where in comparison with other parts of the apparatus Liquid mixture 40 containing carbon disulfide for the production of viscose fibers in explosion-proof closed rooms the amount of hydrogen sulfide is greater than that of the Schwe range after is separated from the sulfur from the carbon. So you are forced to turn off the gas in the evaporated water and the accompanying, second and subsequent baths, with a Krauschwer Separate condensable gases, where a second stage or a purification stage collect where then a purification by Wä- 45 the amount of hydrogen sulfide produced is relatively small see is made with caustic soda and water. is. Therefore, it is usually carbon disulfide As a result, only very small residues from the coagulation bath cannot wedge back into one von is still guided along the regained sulphurization path, but is used together with in Hydrogen sulfide adhering to carbon removes large amounts of generated hydrogen sulfide. The sodium hydroxide solution is stirred with water. This not only has the effect of reducing the the washed out to obtain the purest possible sulfur efficiency of a recovery of carbon disulfide to obtain. carbon, but is also important in terms of public Activated charcoal and other adsorbents are often undesirable for health. When an ancillary in the recovery of carbon disulfide from gas washing and cleaning towers from one made up mainly of carbon disulfide, those mentioned above become existing gas has been used, which has overcome difficulties. However, this leads to during the manufacture of synthetic fibers by increasing energy and construction costs, Viscose process was produced. The adsorbing and it is impossible to be an economically advantageous one capacity of the adsorbent will ever effect recovery. but by hydrogen sulfide, sulfuric acid mist 60 It is also known in a washing and cleaning and other submersion apparatus present in the collected gas, in which an aqueous solution of one punching extremely reduced, which is used to reduce caustic alkali as a dehydrosulfurizing agent the recovery efficiency leads. Around the- was, hydrogen sulfide in the feed gas in the form To avoid this disadvantage, an attempt is made to bring sodium hydrogen sulfide into contact been, hydrogen sulfide, sulfuric acid 65 gene of the gas with a dilute aqueous solution and to remove other substances by washing an entire caustic alkali in countercurrent. Since the molten gas should be diluted with an aqueous solution of a Deny caustic soda washing solution, such as predrosulfurizing agents, z. B. Sodium arsenite and related was mentioned, the sodium hydrogen sulfate