DE1508019A1 - Process for suppressing the metal-catalyzed decomposition of carbon monoxide - Google Patents

Description

_. . "2OOO Hamburg 36, den

Patent attorney Telephone 34 61 31 CBnoang Stephaneplate

Postal checking account: Hamburg 2596 24 Bank: Dresdner Bank AQ., 52S76 / 1O,

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Research and Engineering Company

"Method of suppressing the metal-catalyzed Carbon monoxide decomposition "-

The invention relates to di "prevention of decay of heated carbon monoxide to the catalytic metal surfaces, particularly in the reduction of iron ores to netalli * sßheia iron as well as an improved process for fluidized bed reduction of iron ores by direct contact with Koblenmoncafyd, Kisahungen from carbon monoxide and water, etc. or carbon monoxide and optionally gases containing hydrogen.

Bs is already known, oxydischa iron ores, i.e. for "Ores consisting in part or essentially of egg enosydes ο iff * fluidized bed at temperatures between approx. 535 ° C and the

CD. _

OD ore sintering temperature, i.e. mostly about 9β5 C to metallic

Reduce iron. Such procedures will be

^. usually several fluidized beds as separate, with

-p- same or different temperature operated reduction

Miitereinanügeschaltenü. Usually © .are the © xrsrssfeiede & en FlieSbett arranged in a common reactor »

Bai © INEM typical process for stuf deice PlieSbettreduktien of Sisen @ rs is the finely divided ojcydische iron Mi ore to the upper end of a reactor eye leads and strSmt in disseia of fluidized bed su fluidized bed down "wobai üqv Ossydationszastaad the ore drops of fluid bed au fluidized bed. In each stage the ore is reduced by the upward strobe gases, with the reducing substances of the gas being removed at the same time. If desired, the partly ossified oil can be regenerated and reused without removing the coded gas. In the v @ rscMeSenen Stufes the ore is reduced, for example won Kis & © - (IIX) ~ au osyd magnetic iron oxide (or a 'whose ZysausnesisetsiiKg corresponding mixture) of magnetic iron oxide su & Ei8G ~ LXI) -oxpa. and from this to essentially metallic iron * In general, the metallic product produced contains about $ 85 to $ 95 or more metallic iron *

Such a "method for fluidized bed reduction by Eiseners" is very often separated in the lower section of the reactor separated synthetic gas _a ie <gaseous® mixtures of oil and hydrogen with or without content

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Other gases introduced - Such gaseous mixtures are generally produced by the oxidation or combustion of hydrocarbon products in an oxygen-depleted atmosphere. Such gas mixtures are often enriched with hydrogen, for example by water gas conversion. Because of the endothermic nature of hydrogen

in Eisenersreduktion the use is preferred of gases with relatively high carbon monoxide content in this method, however,%.

In many cases it is also desirable to generate all or part of the reducing gas in situ »In this» procedure, which is generally referred to as direct injection, a carbon hydrogen product is introduced directly into a stage of the process in which the ore is already largely, for example 85 up to 98 $ is reduced to metal _£ · This is how the reducing gases® are generated inside the reactor »Under certain conditions, the metallic iron has a catalytic effect and the hydrocarbon product is converted in situ into a gaseous mixture of carbon monoxide and hydrogen. The presence of xohleranone oxide in the gas mixture supplied or generated in situ is quite desirable for the process, but often leads to difficulties.

n guardian of certain metals, especially Elsen » 9 09809/0434

Oases containing carbon monoxide react very strongly under certain conditions, even with a relatively low carbon monoxide content. Certain forms of the released carbon combine rapidly and violently with the Si sen »for example the reactor and other iron auxiliary equipment» which often leads to severe signs of corrosion (destructive carbon dioxide). In addition, free carbon is formed and thus the efficiency is impaired. Finally, the carbon deposits that occur during the conversion of carbon dioxide into free carbon lead to clogging and failure of the heating devices, pumps and connecting lines, for example 705 ⁰ C these difficulties occur particularly strongly. With the fluidized bed reduction of iron ore it is extremely difficult if only; It is impossible to heat such gases to temperature within the above-mentioned range, so that the decomposition of carbon monoxide into carbon and the destructive corrosion caused by carbonization under such conditions represent an acute danger *

Even in methods in which carbon monoxide-containing gases are heated to higher temperatures to between about 705 and 985 ⁰ C "1st it very difficult to obtain a cooling of the dases by the above-mentioned temperature range

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to report through · It is often desirable to regenerate the reducing gases by separating carbon dioxide and water. To do this, however, the gases must be cooled down through the temperature range mentioned. On the other hand, it is often necessary to heat a cooler gas through this temperature range. Preheating the gases is one of the methods of adding heat to the process. The decomposition of the A

Carbon monoxide, therefore, is a highly troublesome issue which severely hinders the development of direct and indirect implementation methods for the generation and use of carbon monoxide containing gases in the fluidized bed reduction of iron ore.

It is therefore the object of the invention to report these and other difficulties and to propose improved methods for suppressing or inhibiting the decomposition of carbon monoxide and, in particular, to specify an improved method for the fluidized bed reduction of iron ore in one or more bedding zones, in which the decomposition of carbon monoxide occurs when the symptoms of decomposition are normally too severe leading temperatures is effectively suppressed. Sin Such a process should also reduction of the fluidized bed · direct hydrocarbon injection are suitable.

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It has now been found that one can overcome the previous difficulties avoid and get the advantages outlined above *! can, if you add small amounts of certain gas to the gas Adds soli-sulfuric substances »

the invention provides a method of suppressing the metal-KohlenmonoxydZerfalls in ai * F temperature 425-815 ⁰ C heated kohlensiono ^ ähaltigen oases proposed, which is characterized in "that the gas 1 to 1000 ppm sulfur, Be & j®f @ lwasserstoff or wämiezersetzlichen Sulfur added.

The small amounts of sulfur, sea water or heat-decomposing sulfur compounds can be used by blowing in, mixing in or other suitable into the reducing gas containing carbon monoxide

be introduced. The erfindungsgeraSsse method can be applied especially in the fluidized bed reduction of ore Else, thereby enabling suppression or complete elimination of Kohlenmonoxydzerfalls * acidify such gases in the presence of metals in uesentlielien. can be heated or cooled through the temperature range between 425 and Ö15 ° C, preferably 480 to Ö50 ° C without the previous difficulties.

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It has been found that an addition of on the gas »only 1 ppm sulfur causes carbon monoxide decomposition noticeably reduced. For effective suppression of the carbon monoxide decomposition without noticeable difficulties due to the formation of acid are expediently about 5 to 1000, preferably 20 to 500 and in particular 50 to 200 ppm of sulfur, hydrogen sulfide or heat-decomposing sulfur compound fl added. Although these inhibiting substances are also used in Can add concentrations in excess of 1000 ppm, this is generally undesirable because it inter alia the formation of acid increases and, if at all, only minor benefits are achieved * Considerably higher! sulfur can impair the quality of the metal produced.

The reason for the effectiveness of the small amounts of sulfur, Hydrogen sulfide or heat-decomposing sulfur compound in the suppression of carbon monoxide decomposition is not known. However, it is believed that the sulfur or the sulfur compounds in situ one to suppress the Carbon monoxide decomposes effective concentration of hydrogen sulfide result. In any case, it was established with certainty that it was added in advance or generated in situ Hydrogen sulphide, even in very low concentrations, effectively suppresses the decomposition of colloidal anoxides. It can therefore

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both sulfur and any sulfur-containing compounds can be used which can be used at temperatures up to to about 8l5 ° C disintegrates and an effective hydrogen sulfide concentrate! on surrender. On the other hand, to suppress the carbon monoxide decay you can also only use Sulfur compounds that decompose at higher temperatures outside or at a specific point within the Heat the reaction mixture to its disintegration temperature and then on the suppression of the carbon monoxide in the Introduce reaction

According to a preferred embodiment of the invention, added or in situ generated divalent sulfur compounds or sulfides of the general formula R ^ -SHR ₂ can be used, in which R ₁ and Bg are identical or different and are hydrogen atoms or monovalent organic radicals, in particular hydrocarbon radicals such as alkyl "*" Mean alkenyl, alkynyl, aryl, arylalkyl or aralky radicals. The organic radicals can be unsubstituted or substituted, with one or more carbon atoms being replaced by halogen atoms, nitro, amino or carbonyl groups. Cyclic groups can be also contain heteroatoms, in particular one or more sulfur, oxygen or nitrogen atoms

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■. - 9 - suitable sulfur compounds aind: Dinethylsulfid, di-n-proRrlsulfid, £ thyl ~ n-propyl8ulfid, cetyl lsoaaiylsulfld ;, bis-CTrichlotiiethyli sulfide, allyl-ben ^ yl sulphide, Phenyltriohloraethyl sulfide, Phei3yl-l ~ naphtl3ylsulfid, 9 -Metbyl ~ raeroaptophenanthren, ^ - (ßthylffiercaptcO-thiophene, 3-kthylcnre lohexanthlol and others S-Chlnoliiithiol.

are compounds with only one organic Hesf: _f such as Methylstercaptati, Isopropjflaercaptan, B-Ae ^ -lüieroapta-a, allyl mercaptan, ^ -Aoridinmeroaptan, ei. -Mett ^ ri-bönzgrliaerosptan odes? 2-Naplitaiinthiol for sieve sills or used as a mixture with each other or other substances. Hassdel & aischungen or naturally occurring materials containing such substances or forming in situ can also be compressed.

its easy compatibility, its easy-to-use form and its high degree of effectiveness in a low

we use hydrogen sulfide

Complex divalent sulfur compounds such as polysulphics, in particular the disulphides, for example carbon di-sulphide, methyl-ethyl-methyl-sulphide , 2-Fe2? 909809 / 0A34

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Haeh one? In a particularly preferred embodiment of the spinning process , finely divided, oxidic iron ore is whirled up to form a filler layer by upwardly flowing, ferrous monoxide-containing gas, a plurality of series being connected in two rows. The ore was in the various fluidized bed zones, kept at the same or different temperatures, in various stages of reduction. Are thereby preferably one or more mad at temperatures between about ⁰ C 535 985 powered iron (III) ~ od & ReduktionszoB9n a r more preferably operated at temperatures between TÖ5 and 9 ^ 0 ⁰ C iron (II) -Reduktionszonen • »/ ei? ifetiöet * The sulfur or the sulfur-containing compounds are preferably added to the carbon monoxide-containing Heöukfcionsgas and then heated before or during the introduction into the reaction the metal formation is between 85 and 985ε or above.

The following are preferred embodiments of the Invention explained in more detail by means of examples

example 1

In the ball mill, a

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Part size of about 75 to 210 / u of crushed raw Haiaafcite ore (Carol Lake) is used. In an Eiaenerz Redukfciönsreaktor with four fluidized beds, one behind the other, (two iron-III and iron-II reduction zones) the ore was reduced by an upwardly flowing reducing gas with an initial content of 20 # carbon monoxide, 6Ο # hydrogen, 20 $ nitrogen and 80 ppm Hydrogen sulfide whirled up asu fluidized bed layers. The reducing gas was preheated to a temperature range between 455 ° and 70 ° C and then blown into the lowest iron (H) reduction zone.From there the sas yon rni'c & n flowed upwards from a zone lower to a zone higher Oxidation level of iron ore. In represents top iron * · (III) reduction zone was partially burned oxydi8 appliances gas to generate heat for the various Radiiktion3ßtufen · The downside to reducing Siseners in the reactor with increasing reduction

Moved from one level to the next * The iron (III) action levels for the reduction of iron (III) oxides became magnetic iron oxide just like the iron (II) -

operated for the reduction of iron (II) -OjQrds 2u with a temperature of 705 ⁰ C. In the last Elsen- (II) -fieduction stage a rietaH was achieved.

Longer continuous operation of the plant »under

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BAD OBIGlNAU

the above-mentioned operating conditions did not become any Signs of noticeable carbon dioxide decomposition or a destructive carbonization corrosion found.

example 2

The test run according to Example 1 was repeated, but now, based on the gas volume, 150 ppm of hydrogen sulfide were added. The way the fluidized bed works en and the puncture of the procedure proceeded in each Relationship normal and there were no signs of any noticeable carbon monoxide breakdown. In the implementation only a little carbon was formed and that of ferrous metals existing plant locations showed no signs of carbonization. ■.

Example 3

The test run according to Example 2 was repeated, wherein

However, now, based on Kohlenmonoaqrd, 200 ppm ethylmercaptan was added and operating at a temperature of 760 ⁰ C. There was also no evidence of imperceptible carbon monoxide decomposition.

Example k

The test run according to Example 2 was repeated, but 200 ppm benzyl meroaptan were now blown in. There were also no signs of a noticeable - " _ri 90 9 809/0 4 34

Coal aonoaydaterfall observed.

Even with an addition of 100 »150 or 200 ppm Ethy leuIfid, Vinyl sulfide or ethyl propyl sulfide became an essential one Improvement achieved and the carbon monoxide decay suppressed.

To achieve the advantages according to the invention, the The sulfur compounds used at the time of the reduction are present in gaseous form and the eductive components can be smoothly distributed, “regardless of whether they are already added at the beginning or in situ from materials forming such substances be generated. You can use inhibiting substances directly added »blown in or on other catfish in Physically diapered reducing gas «earth.

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Claims (3)

Esso Research and Engineering Company claims 1. Process for suppressing the metal-catalyzed carbon monoxide decomposition in carbon monoxide-containing oases heated ^{to temperatures between 425 and 815 0} C »characterized » in that 1 to 1000 ppm of sulfur, hydrogen sulphide or a heat-decomposing sulfur compound are added to the gas. 2. The method according to claim 1, characterized gekennzelehnet that in the plied bed reduction of fine-digit oxidic bison ores in one or more fluidized bed reduction zones connected in series at temperatures between 535 ⁰ C and the ore sintering temperature, the introduced or generated in situ from injected hydrocarbons, carbon dioxide-containing reduction gases before or 5 to 1000, preferably 20 to 100 and in particular 50 to 200 ppm of hydrogen sulphide or a hot-melt sulfur compound are added during the heating to temperatures between 425 and 85 ° C. or above. 3. The method according to claim 1 and 2 characterized geken ₃ nzeichnet "reacting a mercaptan or an organic sulphide is added. 909 809/04 34
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