DE1444969A1 - Process for removing carbon oxide from low-carbon gases, in particular town or light gas - Google Patents

Description

Dr.-Ing. G. Eichenberg

DipUng. H. Sauerland «« S * * "^ -

Patent Attorneys 1444969

Bank account:

Deutsche Bank AG., Düsseldorf branch

Postal check account: Essen 8734

Telephone number 432732

Use in correspondence too our sign:

Salzgitter Aktiengesellschaft, Berlin

"Process for removing carbon oxide from gases low in carbon oxide, in particular town gas or luminous gas"

For removing carbon oxide from low-carbon technical gases, especially for detoxifying city or Coarse gas, the carbon content of which is mostly less than $ 10 it is known to convert the iiohlenoxide by catalytic oxidation in the presence of steam to carbonic acid or to convert. Also it is no longer new, the carbon dioxide by washing copper lye or on biological Ways to remove the illuminating gas. However, since these procedures are quite uneconomical, they could not be used until now enforce only to a limited extent in practice.

The invention is based on the object of a method for removing carbon oxide from carbon oxide poor To develop gases, especially from town gas, which can be carried out significantly more cost-effectively and at the same time allows the carbon oxide removed from it to be used economically. To this end the invention provides

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suggest that the town gas in a reactor in the presence of hydrogen sulfide or sulfur vapor is heated to such an extent that the carbon oxide is converted into carbon oxysulfide, which is then reacted with ammonia, amines or other substances with reactive hydrogen to form urea or corresponding chemical substances and in this Form from which town gas is removed. In the process according to the invention, the formation of carbon oxysulfide from carbon oxide and hydrogen sulfide or sulfur vapor ^{takes place between 20O 0} O and 1200 ⁰ C, with residence times of 0.01 to 100 3 sec. The short residence times apply to the high reaction temperatures, the long residence times to the low temperatures. Under such test conditions, the formation of hydrogen sulfide and the cleavage of the coking ammonia take place only to a subordinate degree. These reaction conditions are characteristic of the process according to the invention.

It should be noted that it is during manufacture of urea from carbon dioxide and ammonia already known is the carbon monoxide in opposition to sulfur vapor initially to convert into carbon oxysulphide. But it becomes practical hydrogen-free gases with high carbon dioxide contents, in particular assumed blast furnace furnace gas. In contrast to this, city or illuminating gas is a gas that is relatively low in carbon dioxide and is predominantly '

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Contains hydrogen. Numerous investigations have, however shown that if the above reaction conditions are observed and suitable reaction-accelerating contact substances are used the carbon oxide contained in the town gas surprisingly quantitatively even in the presence of hydrogen can be converted into carbon oxysulphide.

... According to the invention, the town gas or luminous gas to be detoxified is first heated in a reactor to such an extent that that the hydrogen sulfide present in the gas reacts with the carbon oxide to carbon oxysulfide with the release of hydrogen connects. #if the hydrogen sulphide present in the gas is not sufficient, the gas must also have hydrogen sulphide or sulfur vapor are added. The carbon oxysulfide formed is then added in a second reactor reacted with ammonia or other substances with a reactive hydrogen atom. Therefore there is basically three possibilities »A first is that the carbon oxysulphide with a solvent from the Reaction gas is washed out, after which the reaction of the carbon oxysulfide in this solvent with the reactive Hydrogen-containing substance takes place. On the other hand, the reaction between carbon oxysulphide and ammonia in the presence of suitable contacts and under suitable reaction conditions also directly in the gas phase capillary-active substances, for example on activated carbon,

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Finally, the reaction gas can be deep-frozen with or without the application of pressure, which is desirable anyway "for the purpose of separating out naphthalene and the heavy, carbon", hydrogen, etc., where The carbon oxysulphide then co-separates as ¹ a fraction, which can then be further processed in the manner described above.

The hydrogen sulphide released in the second reactor can be fed back to the first reactor in which the carbon oxysulphide is formed. Because the ammonia contained in the city or luminous gas is not sufficient to convert all of the carbon oxysulphide , have the second · · ~ ■ 'stage further. Ammoniak.oder ^ other Stoffe.mit.reaktionsfähigem hydrogen are fed atom. It .can abervauchv appropriately be in the second reactor! only present in the gas ammonia for the .Umsatzreaktion and to react the remainder of the carbon oxysulfide in a third reactor with amines or other substances with a reactive hydrogen atom Remove carbon oxide from the gas via the carbon oxysulphide. ', ...,.,.

. The reaction to form the Köhlenoxysulfids ■■■ · - ■ wird.durch ^ Contact materials with high surface areas _f ■ as-eg ,. , Aluminum oxide, silica gel, -. Pumice stone'od * the like .., be

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accelerates. Furthermore, the conversion is improved if the aforementioned contact substances with a coating of metal oxides of group VI of the periodic table are provided, in particular with tungsten and / or molybdenum oxides. One further improvement results when these contacts are occupied with small amounts of metals of group VIII Contacts are expediently converted into sulfides before they are used.

In the second stage, the reactive hydrogen required to convert the carbon oxysulfide is generated containing substances, if they have a very high reactivity, are best implemented in solvents. In the case of substances with less reactivity, the conversion takes place best on activated carbon.

The method according to the invention not only allows an efficient detoxification of the city or coke oven gas, but is also with respect to the further utilization of the removed carbon oxide to urea or the like. of great economic Advantage. It is true that one should initially expect that as a result of the low concentration of carbon dioxide in the town gas the use of this procedure for urea production is more expensive than if you use gas with a higher Carbon oxide content, e.g. furnace gas, is used. Surprisingly, however, due to the combination in the task the increase in costs due to the.

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nen products and the savings compared to conventional town gas detoxification more than offset, so that the method according to the invention works more economically and cheaper overall.

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Claims (9)

.2.1 ... U.Qv ... 196.3;. · An Ue.Tiahr.stxi. zum ... Entfe..r & en .... vo} £ , ....,. 1L. Sheet 7 ... Salzgitter Aktiengesellschaft, Berlin "'■■■■■' - · Claims : ■ 4. Process for removing carbon oxide from carbon oxide poor Gases, in particular from town gas or luminous gas, characterized in that the town gas is heated so high in a reactor in the presence of hydrogen sulfide or sulfur vapor that the .Kohlenoxyd converts into carbon oxysulphide, which then reacts with ammonia, amines or other substances with a Hydrogen atom converted to urea or corresponding chemical valuable substances and in this form the town gas is removed. 2, method according to claim 1, characterized that the conversion of the carbon oxide to carbon oxysulfide at reaction temperatures above 200 C. he follows. % Process according to claims 1 and 2, characterized in that the conversion of the carbon oxide to carbon oxysulfide in the presence of reaction-accelerating contact substances with a large internal surface, such as aluminum oxide, silica gel, pumice stone or the like. is carried out. 809809/0 760 -2.1 · i.Qx * ... ". 1.9-fi.3 -.- an ± J. & r ± aihTB.n: ..: - ziJm: .. Mn ± t.ex.asn: .. MO. u ........ v ..!.! .. 4 * method according to claims 1 Ms 3, d ad ure h g e · k e η η ze i c h η e t that the reaction accelerating Contact substances with a coating of metal oxides of the group TI of the periodic table, especially tungsten and / or molybdenum oxides. 5. The method according to claims 1 big 4, characterized characterized in that the reaction-accelerating contact substances are converted into sulfides before they are used will. 6. The method according to claims 1 to 5, characterized marked that the implementation of the Koh « lenoxysulfides with ammonia or another substance with reactive Hydrogen in the grass phase to a »capillary active Substance, e.g. activated carbon ». 7. The method according to claims 1 to 5, characterized marked that there formed coals " Oxy-sulfide »Washed out of the reaction gas with a solvent will and that the implementation of the lohlenoxysulfida with the reactive hydrogen-containing substance in this Itc5 $ un.gsmitte.l takes place * S * procedure according to. Claims 1 to 5 »thereby. marked that the 'educated Köhl @ n « Q # ys.uifid according to the method known in phosfenohemie »see below chemical substances. uageseii & t 21 * IQ ν ,. 19.62_ an .. "! Learn about .. ..Ent f erne η ... yon ..." _sheet 9 9. The method according to claims 1 to 5, characterized in that iin carbon oxysulfide formed by subsequent 'Eiefkuh ^; quaint of the reaction gas with or oaru; ilaA'eti 1υα. ^: ; before:.; ■: .js - ~ i- ~ iu 'las distant and niLt rsaii ^ io-u: - "''ύά sev- , / ί.}?. ;;>: L. often containing' J t ■■ 11'i'V: t; to chi: mii -'- iiiHi - .i'fco t; ^ V ^ nu:;:. - ^^ t'.t ^: «Lrd. 809808 / Ü760