DE1444972A1 - Process and device for avoiding the accumulation of waste water containing free ammonia and phenols in the production of gases for heating purposes by dry distillation or degassing of coals - Google Patents

Description

Dr «? / Dr.S / Bu / fcr · fiecklinghausen, dec 24.9.1362

Dr. Expl.

Process and device to avoid the accumulation of waste water containing free ammonia and phenols in the production of top oases for heating purposes by dry distillation or degassing of coals ,

Numerous processes are known according to which carbon distillation gases as extensively as possible from tars, naphthalene, phenols, benzene, ammonia, sulfur, cyano and rhodan compounds be released so that the gases meet the purity requirements for long-distance gas and can be used as such

Furthermore, methods are known in which the deposition of Taring, phenols and ammonia from the gases is carried out in such a way that the amounts of waste water to be discharged from the systems are as possible as possible are kept small, with free ammonia and phenols from the Watering removed and ir. Known orphans gained, with which at the same time it is prevented that these toxic components of the sewage get into the plus runs.

The reduction of the expelled amount of water is in this case to reach, DAEs, such as 2 'as DBP 936109 "system of the appropriately designed Gasttihl the wiasrig-tarry condensates possible ait high temperature, s B removed. · 8O ⁰ C, a direct cooler the tars in an effective separator, e.g. 3. be separated by DBP 935 020, and then the still about 80 ⁰ C "poor water is used in a Yerdunster in one de" downstream direct cooling indirect cooler nuf about 25 ⁰ C abgekehlte gas again to about 75 ⁰ C

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H44972

to warm and saturate with steam. It succeeds on theee way to rid the phase of tar oils while being practical to discharge all of the coal water resulting from the coal distillation with the Sas and oo the amounts of water to be diverted to diminish. In order to achieve purity of long-distance gas, the gas is now made up of ammonia, benzene, naphthalene, as well as in a known manner Sulfur, Gyan and Hhodan compounds freed.

In this process, however, non-volatile ammonia mainly ammonium chloride, in which circulated Enrich irrigation water, which is why a small menu of it has to be discharged, otherwise it would eventually be the ammonium salts crystallize and lead to blockages. Part of the discharged, salt-rich water can, if necessary, be replaced by adding salt-free water.

Free ammonia is present in the water to be discharged driven off and in a known manner with that present in the gas Main amount of ammonia together z. B. bound as ammonium sulphate and won.

The phenols are extracted in a known manner and in any Form won.

The necessary technical effort for the production of high quality Long-distance gas is therefore very extensive.

But should that be with the coal deetillation or the z. B. gas obtained directly on a traveling grate or in a chamber furnace and are only used as industrial heating gas in the vicinity of the place of production, this is such a far-reaching purification of the gas is neither necessary nor worthwhile. In this case it is quite sufficient to remove tar from the gases to the extent that that in the gas lines up to the point of use there are no blockages and other disturbances due to the formation of condensate appear. However, according to the methods customary up to now, the start of free ammonia and phenols can be used

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Do not avoid wasting. There is the problem, free Remove ammonia and phenols from it without having to separate them and inevitably generate complex appendices au must.

In the petroleum industry it is known to regenerate process water from the Hinernlöl refinery by stripping and washing.

Process water containing phenols and volatile S and K compounds, such as HoS and iül, _t , are initially freed from volatile impurities with an oxygen-free, neutral gas and the stripped phenol-containing water is washed with a hydrocarbon stream free of volatile impurities, whereupon a hydrocarbon stream containing volatile impurities is washed with the purified process water and the wet water laden with these volatile impurities is returned to the stripping zone. Parts of this carrion to be transferred contain mostly ammonia and phenols. While the volatile impurities such as HpS and NH- are stripped off by a neutral gas stream, it is necessary to extract the phenols in a special frozeas by means of a hydrocarbon stream previously freed from volatile impurities (DAS 1 131 831).

The present invention now relates to a method of avoidance the accumulation of wastewater containing free ammonia and phenols in the production of industrial heaters by coal distillation, e.g. B. in vertical chambers, Horizontalkfimmem or on a traveling grate.

The essence of the invention is to use dr.C iie for purposes beetiiüuten gases with in the circulatory watery i'lüaai ^ -

treated, while, instead, as in known methods, by direct and indirect cooling to 25 ⁰ G, only

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are cooled by direct cooling only to about 60-8O ⁰ C, preferably 7O ⁰ C and at the end of the treatment, almost the total amount of their original water content vaporous carry "so that the seizure substantial amounts of water is omitted and further the fact that, from the account of the enhancement of non-volatile ammonia salts, mainly ammonium chloride, part of the water to be discharged, free ammonia and phenols are practically completely driven off with an inert carrier and the inert carrier gas enriched with free ammonia and phenols is added to the gases obtained from the cave and freed from tar oils «

Ea was found which has not been known, namely that the cooling of the gases preferably only 60-80 ⁰ C ₁ ⁰ C * 7O sufficient to deposit tars and tar oils as far as the fact that channels with their use no interference heating gas by condensation or Clogging occur in the lines. ·

In addition to coke, the new process only produces tar, enough pure gas for industrial heating purposes and a small amount of waste water which is either given directly into the receiving water or, if complete dephenolation is desired, one beforehand can be subjected to biological phenol oxidation.

The proportions of free ammonia and phenols that are returned to the gas after the tars and tar oils have been separated out are included the use of the gas with burned.

The accumulation of ammonia and phenols will be according to the new process avoided.

Erfindungegema.es can for stripping of the ammonia and the phenols from the waste water to be discharged air, flue gas, D _n Rapf or mixtures of these media are used ·

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Vigor t represents aina Sohemaskizte who is working on the new procedure is explained in more detail.

Daa too dar tar template 1 of a coca oven battery coming raw gas is fed through line 8 to the lower part of a direct-acting cooler 2, on the head of which through line 9 in the circuit, water is given up. In the direct cooler 2, constituents which can be condensed from the Oa β, especially tar, are condensed. At the same time, vaporous ammonium oxide is converted into the aqueous phase and thus prevents it from crystallizing out in pipes and equipment in colder places. The gas leaves the direct cooler at the top through line 11, flows through the heat exchanger 5 »in which it is again overheated by a few hours with the water generated in the process, in order to avoid condensation during the forwarding and use of this gas, and leaves it through the line 25. Dia condensates are fed to the tar separator 3 together with the sprinkling water of the Direktkühlera duroh line 12. Duroh line 26 flows to the empty separator as well as the aqueous and tarry condensates deposited in the tar reservoir 1. The aqueous condensates, i.e. the coal water and the water from the receiver and the direct cooler, collect in the upper part of the separator *, they contain free ammonia and phenols. Part of it is returned to the tar layer 1 for cooling the gaa through line Ϊ-).

Dar for the sprinkling? Direct cooler 2 and for discharge A certain amount of water is branched off from the Teeraoheider and duroh lines 18 and 19 the heat exchanger 4 »from here duroh Line 20 to the heat exchanger 5 "through line 21 to the water * cooler 6" to the waaaeriu- and discharge lines 17 and 22, and Bohlieaslioh through line 9 back to the head of the direct » cooler 2 given what the barleselungawaaser's call to scream is closed

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The portion of water to be discharged *, which corresponds to only a fraction of the JLohlewessers , is branched off at 23 and passed through line to on the head of the scraper 7, which is operated under normal or increased pressure. The stripper 7 is fed through lines 14 and 24 in the heat exchanger 4, warmed up inert gas or flue gas, which is also saturated with water vapor in these heat exchangers by introducing steam via line 50, in order to cool the hot water applied to the stripper 7 too much and thus to avoid a weakening of the stripping process. In stripper 7 free ammonia and phenols are ater expelled from the V / DNA by hot inert or flue gas. The vapor containing the ammonia and the phenols leave the scraper at the top through line 15 and are added at 26 to the coke oven gas largely freed from tar in line 2'j . B. tar mist can be done by switching on an electrostatic precipitator.

At the bottom of the scraper 7, waste water flows through line 16 which contains practically no free ammonia and no phenols.

Stripping the free ammonia and phenols from the wastewater in the wiper 7 can also be done with steam. In this Trap is the steam to the scraper 7 through the lines 14 » and 24 supplied.

Examples

A coke oven battery delivers 3,300 tons of coal with a moisture content of 9 »1 % every day, ie 3,000 tons of dry coal

and generates approximately 42,500 Am / r% as ^{leaves the tar seal with 81 0} G water vapor saturated * and enters the direct cooler (2) at this temperature (Fig. 1).

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Dae Gae contains 34-42 g, converted to waeeer-free Tar oils per Hm, 0.7-0.9 g of which are phenols.

The direct cooler runs at 265 w? üreislnufberieaelungswasaer of 40 ⁰ C charged. Gae of leaving the direct cooler wasserdampfgeeättigt with a! Temperature of 7O ⁰ O and contains, converted to water freedom, even 10 to 20 g per tar oils Na, of which 0.55-0.75 g phenols bind.

is superheated ^{to 75 °} C. in the heat exchanger (5). The Geeamtkondeneat leaves together with the irrigation water to the direct cooler (2) with a temperature of 80 ⁰ C and enters the -Teerecheider (3).

^{Every hour 400 m J} of the separated water are returned from the lower part of the tea separator to the template. D s _a rest Wacser is withdrawn through line (18) from the lower part of the Teerscheiders 80 ⁰ C and 285 m hourly eye to the heat exchanger (4) which it leaves at 78 ⁰ C. In the heat exchanger (5) it is further cooled to 77 ⁰ C. Schlieaslich it wixd cooled in Waeserkühler (6) with 530 mVh water of 77 ⁰ C to 40 ⁰ C and abandoned at this temperature to the direct cooler (2).

Of the water withdrawn from the tar separator through line (18), approx. 2.9 m per hour are added to the scraper (7) from the second and at the top of the gas at the exit from the direct cooler (2) on the one hand and the heat exchanger (5) on the other hand (72 ^ 73 ⁰ C). In the present example, it amounts to only about £ 15 of the dblichtrweiae in the coal distillation as condensation water! amount. Through line (H)

etündlioh 1 200 um flue gas are sucked in, saturated in the heat exchanger (4) by adding 800 kg of water vapor and on 78 * heated. The free ammonia and phenols persistent swirl

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des are mixed with the coke gas at a temperature of 78 ^° C. at (26). This now contains, in addition to the above. 30 g of benzene and about 10-15 pounds of borne hydrocarbons per Nm of practically all free ammonia and all phenols which are formed in the distillation of coal and which are in the condensate water in the conventional processes

inaüilriiMtn '.

is then put to its use, e.g. underfiring a D _R mpfkeBsels.

At the bottom of the scraper (7) there are 2.9 m ^ of water every hour deducted, which is practically free of free ammonia and phenols is.

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Claims (2)

mm Q ·. -144 4 W 2 1. Process to avoid the accumulation of wastewater containing free ammonia and phenols in the extraction of gases for heating purposes duroh! Dry distillation or degassing of coals, by treating them with aqueous liquids under such application tires that the üaae in the end almost the total amount of their original water content carry as steam and in the process also does not remove substantial amounts of water, characterized in that the gases are cooled by direct cooling with aqueous liquids to 60-80 ⁰ O, preferably to 70 ⁰ G, and that a portion of the treatment is -jers is regularly defined from the plant to avoid disturbing enrichment with fixed ammonium salts, free ammonia and phenols are practically completely driven off from it with an inert carrier gas and the carrier gas enriched with ammonia and phenols is added to the carbon gases. 2. The method according to claim 1, characterized in that tils Carrier gas when driving off ammonia and phenols, air, Flue gas, steam or mixtures of these media can be used. 3 · Device for carrying out the method according to claim and 2, characterized by a cooler (2) for direct cooling of the gases, a tea separator (3) for separating the tars of water, two heat exchangers (4) and (5) and a water cooler (6) eua indirect cooling of the circulating irrigation water, as well as by a scraper (7) for expelling ammonia and phenols as well as the one intended for discharge Sewage. 9Q9806 / 08CH