DE2461025A1 - METHOD FOR REMOVING ACETYLENE - Google Patents

Description

Process for removing acetylene

The invention relates to a process for the selective removal of acetylene and a catalyst used therein will. The catalyst for removing acetylenic impurities from gaseous organic product streams contains at least Fe and Ni, other elements of group 8, 1b, 2b, 4b, 6b and 7b of the periodic table, an alkaline earth metal and an alkali metal.

The invention relates to a method for the selective removal of acetylenic compounds from gas streams and a catalyst used therein. The process of the invention and the catalyst of the invention are special useful for reducing acetylenic compound impurities in organic compound gas streams.

The term "acetylenes" or "acetylenic compounds" as used in the present application means Acetylene, vinyl acetylene, methyl acetylene, ethyl acetylene, etc.

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Such "compounds often appear as impurities in various organic product streams. For example, oxidative or non-oxidative dehydrogenation occurs of C /.- Co hydrocarbons containing at least one

HH ^{4 8}

it.
-CC group included in the manufacture of the appropriate

dd
Ethylenically unsaturated hydrocarbons small amounts of acetylenes .. In many uses of ethylenically unsaturated hydrocarbons, for example (for butadiene) in the production of styrene-butadiene rubber, only very small amounts, generally less than 1000 ppm acetylenes in the butadiene are acceptable. Similarly, in the production of olefinic hydrocarbons, cracking of the hydrocarbon feed streams produces certain amounts of acetylene. Some ethylene recovery processes, such as the copper (I) salt process, require that the acetylenes be removed first because acetylene reacts with the copper (I) ions to form an explosive compound. Ethylene, which is used for polymerization purposes, requires almost complete removal of the acetylenes.

So much effort has gone into finding procedures for removal of acetylenes from organic streams, in particular Cp-Cg paraffinic and olefinic hydrocarbon streams, to remove. Two types of processes are used: (1) physical, which involve distillations, extractions, extractive Distillation and various combinations of physical processes are used, and (2) catalytic processes. Two catalytic processes are described in U.S. Patents 3,476,824 and 3,728,412.

The invention relates to a catalyst and a process for reducing acetylenic compounds in gas streams. Acetylenes are considered impurities in the present invention. The gas stream can be other organic Contain compounds, especially hydrocarbons,

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_ 3 -

which are the main or desired products in the stream. The hydrocarbons preferably contain 2 to 8 carbon atoms and more preferably 4 to 6 or 8 carbon atoms.

The inventive method is characterized in that the stream of organic compounds, which is a low Amount of acetylenic compounds contains, with a catalyst for reducing the amount of acetylenic compounds treated in the stream, the catalyst being the main cation elements, expressed by weight, a A compound containing at least Fe and Ni and a metal selected from the elements of Groups 8, 1b, 2b, 4b, 6b and 7b of the periodic table, an alkaline earth metal of an element of group 2a of the periodic table and an alkali metal of Contains group 1a of the periodic table. All references to the periodic table in this application refer to the Periodic Table on page B-3 of the 51st Edition of the Handbook of Chemistry and Physics (1970-71), Chemical Rubber Publishing Company.

The inventive method and the inventive catalyst are particularly useful in the oxidative vapor phase dehydrogenation for the production of unsaturated hydrocarbons, in which a stream of hydrocarbon compounds is oxidatively hydrogenated to form a product stream which contains an unsaturated hydrocarbon product and acetylenic compounds as impurities. The improvement of this process consists in treating the product stream in the vapor phase at a temperature of at least 250 ^° C. and a content of less than 5 mol% free oxygen with the solid catalyst as described above. A particular advantage of the present invention is that the gas product stream is treated without the need to convert it to a liquid stream, as is required in the known acetylene separations.

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The acetylenic compounds are serious impurities in an unsaturated hydrocarbon product and they must be essentially completely removed in order to obtain a Obtain product of suitable purity, i.e. a product containing acetylenic compounds of the order of some Contains parts per million (ppm). The essentially complete removal of the acetylenic compound is off very difficult for various reasons. Mainly because they only represent a very small percentage of the gas flow, the should be cleaned. Usually the acetylenic compounds are in an amount below 1.0 mol-9f> contained in * gas stream and usually they are contained in an amount below or up to 0.5 mol% in the gas stream. in the generally the gas stream will contain at least about 3000 ppm acetylenic compounds based on other organic compounds Compounds that are present, 'such as on ethylenically unsaturated hydrocarbons. Your low concentration in the flow makes the acetylenes very difficult to remove. In addition, form between the acetylenic compounds and various other hydrocarbons present Azeotropes.

Their low concentration in the stream and the small difference in the boiling points of acetylenes and other products mean that the acetylenes are very difficult to remove. In addition, azeotropes can form between the acetylenic compounds and various other hydrocarbons present.

The organic compounds according to the invention Processes can generally contain 2 to 20 carbon atoms. A preferred group of compounds are hydrocarbons and those with 2 to 8 carbon atoms or 4 to 6 carbon atoms. The process is a purification and so are the acetylenic compounds present only in small amounts compared to the other organic compounds in the stream. The main part of the

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Electricity can be made up of saturated and unsaturated (exclusively acetylenically unsaturated) compounds and it can contain straight-chain or branched-chain compounds and similarly, the compounds desired can be cyclic, acyclic, aromatic, or mixtures of these compounds. The acetylenic compounds will preferably be present in the stream in reduced amounts.

In general, the atoms of Fe, Ni _f, the other metals of groups 8, 1b, 2b, 4b, 6b and 7b of the periodic table, the alkaline earth metals of group 2a of the periodic table and the alkali metal oxides of group 1a of the periodic table are effective in the process according to the invention. The atoms can be in the form of metal compounds such as oxides, salts or hydroxides. Many of these metals, oxides, salts and hydroxides can change during the preparation of the catalyst, during the heating in a reactor before they are used in the process according to the invention, or they are converted into a different form under the reaction conditions described, but these materials do still act as an effective catalyst in the defined process for carbonyl removal or elimination

to surrender. For example, the metal can be in the form of nitrates, nitrites, carbonates, hydroxides, acetates, Sulfites, silicates, sulfides, etc. are present. For example, iron nitrate and iron sulfate can be at least partially in convert the corresponding oxides while heating in a reactor at a reaction temperature of about 550 ° C. These salts of the defined metal groups, which are normally stable at the defined reaction temperature, can similarly be effective under the reaction conditions described. However, some metal compounds are more effective than other compounds of the same metal and therefore the compound that gives the best results should be chosen will. Preference is given to using catalysts which are solid under the conditions for removing acetylene. Show preferentially

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the compounds have a certain basicity, for example in the case of oxides, carbonates or hydroxides.

Examples of preferred catalysts contain, in addition to Pe and Ni, at least one metal such as Cr, Mn, Cu, Zn and / or Zr, at least one alkali metal such as Li, Na, K or / and Rb and at least one alkaline earth metal such as Mg, Ca, Sr or / and Ba.

Of the elements of group 8 of the periodic table, in addition to Fe and Ni, the metals of the platinum group are preferred. Valuable compounds include, for example, beryllium oxide, magnesium acetate, magnesium bromide, magnesium oxide, magnesium;} ο did, calcium oxide, calcium acetate, calcium oxalate, calcium chloride, calcium bromide, calcium iodide, calcium fluoride, calcium carbonate, strontium nitrate, strontium chloride, strontium oxide, barium hydroxide, strontium chloride, strontium hydroxide, strontium chloride , Barium hydroxide, barium sulfate, barium bromide, barium iodide, beryllium chloride, copper (II) bromide, copper (I) chloride, copper (l) oxide, copper (II) oxide, copper (l) silicide, copper (I) sulfide, copper (II) phosphate, silver oxide, zinc fluoride, zinc oxide, zinc-o-phosphate, zinc phosphide, zinc-o-silicate, Z.lnkm-silicate, zinc sulfide, cadmium oxide, titanium dioxide, zirconium oxide, CrBr ₂ , Cr ₂ O ^, Magnesium dioxide, manganese disilicide, iron (II) oxide, iron (III) oxide, FeJDr etc. and mixtures thereof. The term "mixtures thereof" includes compounds thereof such as ferrites. For example, a catalyst can contain zinc ferrite together with barium oxide and Na ₂ CO ^.

The elements of the platinum metals are the elements in the 5th and 6th periods of group 8 of the periodic table. These elements are ruthenium, rhodium, palladium, osmium, iridium and platinum. Preferred catalysts are platinum, palladium, compounds and mixtures thereof. Suitable catalysts are those such as palladium metal, palladium monoxide, platinum oxide (II or IV), Platinum metal, platinum-rhodium alloys, etc. The elements of groups 1a, 1b, 2a, 2b, 4b, 6b, 7b and 8 as defined are the main active components of the catalyst.

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Alkali metals can preferably be used in an amount of up to 40% by weight, in relation to the other metallic elements (calculated as elements) may be present, usually in a range of about 0.5 to JO% by weight. The preferred alkalis are potassium, Sodium, rubidium, lithium and mixtures. Aluminum can be present in quite large amounts, but the exact effect of aluminum is not known because aluminum itself does the implementation not particularly catalyzed. Non-metals such as silicon can be present. Oxides, hydroxides or carbonates or Compounds which are converted into these compounds under the reaction conditions, the carbonyl compounds being destroyed are preferred. Components or anions that suppress the action of the defined metal elements or eliminate should be avoided.

A preferred type of catalyst is one which contains iron, and particularly preferred are those which have iron as the main metal or cation component in terms of weight. Another preferred catalyst is Fe, Ni and Zn. The iron and other compounds can be oxides or others Compounds may be present or they may be present as, for example, hydroxides, carbonates, nitrates, acetates, etc. be. One form are ferrites such as magnesium ferrite, manganese ferrite, calcium ferrite, barium ferrite, strontium ferrite, zinc ferrite, magnesium chromium ferrite, Zinc-chromium ferrite, calcium-zinc-ferrite, zinc-nickel ferrite, mixtures thereof, etc. The ferrites can do more included as a metal as explained. Methods of making ferrites are described, for example, in U.S. patents 3,284,536, 3,270,080, 3,303,235, 3,334,152, 3,342,890, 3,526,675, etc. Mixtures of iron oxide with others Compounds such as oxides give excellent results. You can combine iron and nickel like one Compound or other combinations such as ferrite or a mixture of compounds with at least one metal of the ■ Group of alkali metals such as Li, Na, K, Rb, alkaline earth metals such as Mg, Ca, Sr, Ba, metals: group 4b such as Ti, metals, of group 6b such as Cr, metals of .Gruppe 7b such as Mn, metals

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of group 8 such as Co, metals of group 1b such as Cu, metals of group 2b such as Zn. In addition, Al, Si, P, Bi can be present. Examples of mixtures of iron oxide with other compounds are described in US Pat 461 "Wf. and 3,308,193.

The nickel present in the catalyst of the present invention can be in any combined form such as Zn Ni ferrite or as a separate compound such as Zn ferrite and NiO. The amount of nickel that is used is small and although not critical, there will generally be from 0.25 to 20 weight percent nickel based on total catalyst weight (excluding carrier), or more preferably 1 to 10% by weight.

Another feature of the present invention with regard to the purification of the effluent in the oxidative Dehydration is the presence of carbonyl compounds as impurities. Generally the carbonyl compounds Contain 1 to 8 carbon atoms, for example 1 to 6 carbon atoms when a C ^ -Cg compound is dehydrated, and they will contain 1 to 2 carbonyl groups. Formaldehyde should be included in this definition. These materials are also present in small, difficult-to-remove quantities and are very disadvantageous for the ethylenically unsaturated hydrocarbon product. In a related German

Patent specification (patent application P 23 04 963.0

corresponding to Serial No. 223,363, filed on February 3, 1972) discloses a method and a catalyst for the removal of these Carbonyl compounds described. A large number of useful catalysts are disclosed in the cited patent for the removal of carbonyl compounds. However, it has been found that nickel in the form of 33% by weight nickel ferrite to 67% aluminum oxide cannot be used because the catalyst coked or not working. It has been found that other iron compounds that. does not contain nickel for removal of carbonyl compounds are highly effective. It was therefore very surprising and unexpected that in the inventive

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Catalyst which contains nickel as an essential component, the acetylenic compounds and carbonyl compounds are essential can be reduced without coking. The particular effect of the compound according to the invention can be based on the synergistic Effect of all of the compounds described herein, despite the adverse effect of nickel, when used in amounts less than the essential ingredients.

The acetylene removal catalyst or reduction catalyst of the present invention is also an excellent one Carbonyl removal or reduction catalyst, since both functions are performed by this catalyst minimal loss of other hydrocarbons in the stream. When eliminating the nickel component from the According to the invention, a decarbonylation catalyst remains, as described in the application mentioned will. The present invention can thus be regarded as an improvement of the known decarbonylation catalyst, the improvement being that the essential nickel component in the reduction of acetylenic compounds is also used.

The following is a suggested mechanism that is based on observations of the process and not as a limitation should be viewed. It is believed that the metal and the alkaline earth metal are the major decarbonylation participants and that the metal is a "catalyst" for the water gas reaction with hydrogen among the products and that the alkali metal is an activator for the metal-water gas "catalyst" is. The nickel is believed to be a hydrogenation catalyst, with the acetylenic compounds be hydrogenated. The small amounts of hydrogen inherently present in the system appear to be sufficient to do this to effect, and in addition these components can effect other functions and have synergistic properties, which are not yet known.

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This system is not used as a conventional oxidative dehydrogenation catalyst considered due to the presence of alkali metal, which has been observed to have the effectiveness of eliminated certain oxidative dehydrogenation catalysts. For example, the water gas reaction is important to the catalyst clean and remove the coke that is formed during the treatment. The water gas reaction is but less important when oxygen is present. In typical use in the present invention, for example where the catalyst bed according to the invention is used immediately after or on the oxidative dehydrogenation, the reaction stream is poor in oxygen. Although oxygen can be injected, as will be explained below, it is probably best not to.

Although the alkali metals are the main activators for the water gas Considered "catalyst", the alkaline earth metals also have a certain capacity in this regard and can replace part of the alkali metal. This is particularly suitable when there is sufficient oxygen, to help decoke the catalyst.

The catalyst according to the invention is reduced before it is used. The reduction is carried out in manner known per se, however, a flow of hydrogen through the catalyst for 5 minutes to several hours, for example 5 hours, suitably at temperatures of 260-870 ⁰ C (500 to 160o F ^0). As little as 5 to 30 minutes of time at 427 to 704 ^° C (800 to 1300 ^° F) is useful, and similar results are obtained at 3 hours in the same temperature range. In general, the temperatures of around 482-593 ° C (900 to 1100 ⁰ F). It has been observed that the reduction is beneficial for the acetylene reduction. Other reducing agents such as n-butane can be used to reduce the catalyst.

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The catalysts according to the invention can be used as such or catalyst supports can be coated with them will. Catalyst supports are known and include such compounds as aluminum oxide, silicon dioxide, silicon carbide etc. Diluents can also be used in the catalyst. must be incorporated as long as the diluent does not interfere with the action of the catalyst. Should be preferred Carries a low surface area and a low acidity exhibit.

The gas mixture that is being treated - and that of the acetylenic ones Containing compounds as an impurity can come from a variety of sources. However, the invention is special ' suitable for the purification of gas effluents that occur in the oxidative dehydrogenation of organic compounds including Hydrocarbons arise in which air or oxygen, diluted with non-condensable diluents such as Nitrogen or helium is used. Examples of oxidative dehydrogenation processes are given in US patents 3,207,805, 3,284,536, 3,320,329, 3,342,890, and 3,476,824.

Organic compounds to be dehydrated can be acyclic, cycloaliphatic or alkylaryl compounds with 3 or 4 to 9 carbon atoms containing at least two adjacent carbon atoms, each of which Carbon atoms bonded to at least one hydrogen atom contains. Olefins, diolefins or unsaturated compounds can be made from several saturated compounds for example, 1,3-butadiene can be produced from n-butane will. A mixture of monoolefins and diolefins can also be made as a mixture of 1,3-butadiene and butenes from a feed of a mixture of n-butane and butene. Cyclohexane can become cyclohexene and / or benzene are dehydrated. Ethylbenzene or ethylcyclohexane can be dehydrogenated to styrene. Good results can be obtained with an organic feed material

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which are at least 50 and at least 75 mol% an acyclic aliphatic hydrocarbon. Hydrocarbons with 4 to 5 carbon atoms with a straight chain with at least 4 carbon atoms, for example those with a single double bond, can be used will. The mono-ethylenically unsaturated compounds or mixtures of saturated and mono-ethylenic are preferred unsaturated compounds. Hydrocarbons of 4 'to 8 carbon atoms are a preferred feedstock, with n-butane, n-butene, isopentane, isopentene, ethylbenzene and mixtures thereof give excellent results.

Oxygen is generally in the area in the dehydrogenation zone from about 0.20 moles of oxygen to 2.0 or 3.0 moles of oxygen / mole of hydrocarbon to be dehydrogenated, initiated. A preferred range for the oxygen is about 0.3 to 1.50 moles oxygen / mole hydrocarbon, to be dehydrated. One can either use air, oxygen, or oxygen diluted with a diluent such as nitrogen, helium, etc. The oxygen can be in gaseous form or with a solid oxidizer as in U.S. Patent 3,420,911. Steam can introduced into the dehydrogenation zone in amounts of about 2 to 40 moles of steam / mole of hydrocarbon to be dehydrogenated will. An advantageous range is from 2 to 20 moles of steam / mole of hydrocarbon.

The dehydrogenation reaction can be carried out in the absence of contact catalysts can be carried out, but better results are obtained when the reaction is carried out in the presence of metal or Metal compound catalysts is carried out. The dehydrogenation reaction can be carried out in a reactor with stationary or fluid layer can be carried out. Reactors commonly used for the dehydrogenation of hydrocarbons too Butadiene used can be used. The total pressure in the dehydrogenation zone can suitably

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be around atmospheric pressure. However, higher pressures or a vacuum can also be used. Pressures such as from about atmospheric (or below) up to about 7.3 to 21.1 atmospheres (100 to 300 psig) can be used. The dehydrogenation reaction is usually carried out at a temperature of at least about 250 ^° C., such as at a temperature which is above about 300 or 375 ^° C., and the maximum temperature in the reactor can be about 700 or 800 ^° C. or it can possibly be higher than 900 ^° C.

The effluent from the dehydrogenation zone may contain the impure unsaturated organic products, various impurities including oxygenated hydrocarbons, non-condensable gases and perhaps unconverted feedstock, oxygen and steam. If air is used as the source of oxygen, nitrogen will be present in relatively large quantities as a non-condensable gas. Steam can be present in an amount up to 96 mole percent, based on total effluent, such as from about 5 to 96 percent. On an anhydrous basis, the organic phase including the dehydrogenated product, unreacted feedstock, oxygenated hydrocarbons, polymer and tar and precursors thereof, and any organic decomposition products will generally constitute, and will, from about 1 to 50 mole percent t of the effluent generally in the range of about 3 to 30 mole percent based on the effluent. Also on an anhydrous basis, the non-condensable gases such as nitrogen or COp will generally be present in an amount of about 5 to 93 mole percent based on total effluent, but more often they will be in the range of about 20 or 40 to 80 mole percent. %.

The term "non-condensable" or "inert non-condensable" Gases refers to those gases, with the exception of the hydrocarbons, such as nitrogen, COp and CO, which are among the Do not condense under the conditions that occur.

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In the processes in which the outflowing stream, which is passed over the catalyst according to the invention, is low in oxygen is, in particular less than 1 mol%, based on making up the reactor effluent, the water gas reaction is an important feature and some steam is essential to the catalyst technically suitable to use. If the effluent comes from oxidative dehydrogenation, Steam is usually a common component of the effluent Be current and in substantial quantities, for example 3 to 30 moles of steam / mole of total organic compound (e.g. unsaturated hydrocarbons and carbonyls), . to be available.

The effluent gases leaving the dehydrogenation zone will have at least 400 or 450 ° C in general, a temperature, suitable ranges between 450 and 500 ⁰ C and 800 ⁰ C or 900 are ·, depending on the particular dehydrogenation process. According to a preferred embodiment of the invention, the gases are introduced directly into the catalyst layer for the removal of acetylenic compounds or they are at least passed into the catalyst layer before the condensation of the vapor from the gases flowing out. This catalyst layer can be present in the same reactor chamber as the dehydrogenation layer. Inert packing material can optionally be packed between the dehydrogenation catalyst and the carbonyl destruction catalyst. In general, the reactor effluent will not cool appreciably before it encounters the acetylene removal catalyst and therefore the temperature will be within the ranges as for the reactor effluent. Optionally, the gaseous feed material can be cooled or heated prior to contacting it with the acetylene removal catalyst in order to obtain an optimal temperature for carbonyl destruction without adversely affecting the products. It is also within the scope of the present invention to remove some or all of the reactor effluent prior to treatment with the catalyst.

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Usually the composition passed to the acetylene removal catalyst will be at least 3 or 5 moles of non-condensed vapor / mole of total organic compound such as hydrocarbon and it can "for example Contains 3 Ms 30 moles of steam. The reactor effluent will generally be less than 5 mole percent free oxygen and it may initially be referred to as less than i MoI- ^, " on the reactor effluent. It is possible to add oxygen to the reactor effluent before adding it to the Treated acetylene removal catalyst.

The presence of oxygen can be detrimental to the acetylene removal catalysts of the present invention to unsaturated compounds, for example hydrocarbon products, can be oxidized. Although oxygen If the catalyst prevents coking, unsaturated products may be formed. For this reason, the present invention is carried out so that less than 5 mol% and preferably less than 1 mol% Free oxygen is present in the feed that is passed over the catalyst of the present invention (on a steam-free basis).

As stated above, the nature of the feed streams is too the catalyst by which the acetylenic compounds are reduced, usually so that a small amount of free hydrogen, based on the organic components, may be present, usually 10 mol% or less and preferably 1 mol-Ji or less. It can be from or around 0.5 mole percent hydrogen or more preferably 1 mole percent is present be. The presence of hydrogen can be important when considering the mechanism in the reduction of the acetylenic compound comprises hydrogenation. However, in the mechanism at all ke, can occur in hydrogen or, if it does, the mechanism can proceed differently than via hydrogenation. In any event, it was observed that hydrogen in the feed stream, of the catalyst where the acetylenic

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Connections are reduced, leaves, is present.

Hydrogen can be added to the feed streams in order to adjust the content of the current within the limits given above. The absence of hydrogen or a the amount less than that described above affects the present Invention not. Since only small amounts of acetylenes are usually handled, sufficient hydrogen must be used in situ for use when hydrogen is used as noted above.

The gaseous composition introduced into the acetylene removal catalyst zone preferably contains, with the exception of any water present, µm or from 3-5 to 80 molar-6 unsaturated hydrocarbon µm or from 0.0005 to 2.5 Mo 1-% carbonyl compounds, um or from 0.0001 to 2.5 mol%: acetylenes and um or from 5 to 93 vol% non-condensable gases (ie gases which do not condense under the contact conditions with the catalyst), all Information is based on the total moles of gaseous composition which is passed to the catalyst.

After the catalyst has been used for a period of time, it can be regenerated by oxidation with air and / or with steam will. Methods for the regeneration of dehydrogenation catalysts to remove coke can be used will.

The following examples illustrate the invention without restricting it. All percentages are unless otherwise indicated, expressed by weight.

Examples 1 to 8

Semi-technical experiments were carried out with different catalyst compositions performed to remove acetylenes. A 60.96 cm (24 inch) long rust-free reactor was used as the reactor Steel pipe with an inside diameter of 2.54 cm (1 inch) in

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a 3100 watt oven with three separate temperature control elements. The., ObererL ZP ^^ m ^^ ß.in ^ ß ^ .dXentejj .., as. _} .Steam-. super.erhi.tze.r ,,,, Das., Koh ^ enwiL ^ ser ^ pfi-Charging material. was., in, the üWrerhitztf ηJ ^ ampf. e ^ nguided, beypr \ der. Steam. a ^ pxyda.tiyer.De ^^ ....

approx., .. length ,, ypn.25, <4. cm _s .. (10th inches) entered. Under _;; the... ,. . atiyej ^ D ^^

dü ^^ j £, 7 cm \

(5 inch) acetylene removal chip attached .., samples of the effluent material are taken from above the acetylene removal layer and.: .. Aiaalyses.are taken with it. chrpmato -. ,,. graphical gasri; iüss..j.gkeitsyerfahren carried out ,,. _; ,

The Besphipkungsmate _r rial. to the. .oxyd.atives _; Dehydration catalyst ,, (b ^ ei aedem .. ^^ example. 4as, same) is 9S9i-% ten-2,. .. with einx, LHS> V yon ^ jJ50j über.er, .der oxyd.at:L^ ^en dehydration ^ zQ | ie _r p,. ^ h Mol. ^ auqrs ^ of ^.

Was.sgrs. ^ Off and; "20, Mql ^ .DJιmpf / ito ^ l hydro er material. The inlet temperature in the pyrogenic dehydration zone is -349 ° C (60 ° F). iind the. temperature, ernungskatalysatorzone in the Acetylenentf is approximately 538-566 ⁰ C (1ÖÖÖ to 1050 ⁰ F). Each experiment is carried out for many hours, with the results listed below being obtained after several weeks of operation.

example

An acetylene removal catalyst is prepared as follows :; ; 6805 x; g ^ nle ^ O ^ il 1 ^ 5b gfSaGO ^; <FMG), and 890: g NiCO ^. : ■: (49.4%. Jiir.Bak0: riSiReagens) ^ Mejrdenr ^ tKPGkenvwith each other; yer- =; - .. ·. · ■; ■ mixes. 1246 g NaOH (Bakfers: -iBgagems ^: are: dn a: solution ^; - with 2.83 liters of distilled water. This solution is added to the dry mixture and pellets ^ with; eijiemjr .., ;; ■■ / ■ diameter yon be 0.24 cm (3/32. inch) processes, and these dried. The "Acetylenkatalysator is tested as described above .. The. oxidative 'dehydrogenation catalyst results in a conversion / selectivity and a yield of 74 for butadiene, 95 and 70 mol%, respectively. The following by-products

(based on butadiene)
and after ^ the stream over the
was directed: '-K cc "

,,,,, .. ,,,. , -. Above the layer Below the layer "'ppm

Formaldehyde 2000 ? Ι & - ^:.

Acetaldehyde 1000 -'vi

Acrolein '; 200

Vinylacetylene "'*" 1800 cs ^ Ti ^: -.; ^^ - ^ ~

Similar catalyst preparative procedures are used in each of the following examples. The results "are expressed as" % reduction in secondary product risk in "the flow".

Example 2 . ...,

■ ■ ': ·; ^ - "J i' ^ c'lO"'!

Catalyst composition 6: 1 ZnFe ₂ O ^: BaW ^ i ■■ 7: ^ _H - ^

'~ "" Well wl; l · "3.Λ

° / o reduction *

Formaldehyde 98

Acetaldehyde ^, -.- J- _

Acrolein ■ ^:. "-:> :. ■. _;;; - j ,: · -: 80;:.:. .- .: Vinylacetylene ' ^: '':' -. '■" ■■ i'' ■ · 13

Example -5

Catalyst composition: 6: 1 Y ₂ / BaCO ^;,

7.5% Na 1.0% Ni

% Reduction

Formaldehyde 100 Z : ■ »·

Acetaldehyde. .. - _{; :} . _λ 80 _v acrolein ',. "_._; ·· ,, - 80

., Vinyl, ..; _{._,:} s ^ 65

Example 4

Catalyst composition 6: 1 ZnFe ₂ O ^: BaCO ^

+ 7.5% Na + 3% Ni

formaldehyde
acetaldehyde
Acrolein
Vinyl acetylene

Example 5 Catalyst Composition

ffi reduction 98
80
80
80

J) ₁ ^ : BaCO, - + 7.5% Na + 10% Ni "

% Reduction

Formaldehyde 98

Acetaldehyde - 80

Acrolein 85

Vinyl acetylene 95

Example 6

Catalyst composition 6: 1 ZnFe ₂ O ^: BaCO ^ ₅

+ 7.5% Na "+ 0.10% Pt

% Reduction

Formaldehyde 95

Acetaldehyde 40

Acrolein 40

Vinyl acetylene 5

Example 7

Catalyst composition 6: 1 ZnFe ₂ O *: BaCO,

+ 7.5% Na + 5.0% Cu % reduction

Formaldehyde 95

Acetaldehyde 40

Acrolein 40

Vinyl acetylene 9

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Example 8

Catalyst composition 6: 1 Fe ₂ O ^: BaCO,

. + 5.0% Na

% Reduction

Formaldehyde 95

Acetaldehyde 75

Acrolein 75

Vinyl acetylene 10

Examples 9 and 10

To further confirm these results, catalyst compositions according to Examples 2 and 4 in a large pilot plant under the same conditions checked. Both showed excellent carbonyl removal but failed acetylene removal with the non-inventive Composition (Example 8) only a very small improvement can be observed.

Example 9 Example 10

(Catalyst according to example 2) (catalyst according to example 4)

^e 6: 1 ZnFe ₂ O ₄ : BaCO ₃ · ^Φ 6: 1 ZnFe ₂ O ₄ : BaCO ₃

+ 7.5% Na + 7.5% Na + 3.0% Ni

% Decrease% decrease

83 days in operation Days in operation

2Γ DD

Formaldehyde 98 100 98

Acetaldehyde 75. 80 76

Acrolein 80 90 78

Vinyl acetylene 15 80 90

reduced with H ₂ before commissioning

Examples 11 and 12

An attempt was made by a 25 ecm catalyst from 3.36 to 2.38 mm (6 to 8 mesh U.S. Standard) in a 2.54 cm (1 inch) Vycor reactor operating in a temperature range of 559 to 575 ° C was checked. The feed material in

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the reactor contained:

ml / min

Aldehyde solution (50/50 mixture of HCHO and

CH ₃ CHO) 6

Nitrogen. 720

Butadiene-1,3 575

CO ₂ 210

The results were recorded at the end of 80 minutes. The catalyst contained 33% by weight nickel ferrite deposited on 67 % by weight aluminum oxide support. The catalyst coked quickly. A catalyst comprising 33 wt.% Strontium, deposited on 67 wt.% Alumina support containing not coked to give a 79% ig ^e Carbonylentfernung under the same conditions.

Example 13

A catalyst for the removal of acetylenic and / or carbonyl compounds from a gas product stream is only of technical value if the materials which are considered to be products are not also removed in the process, or if they are removed in such a way that only very small amounts of them are lost. In the present example, a catalyst as used in Example 4 is used, ie the composition 6: 1 ZnFe ₂ O ^: BaCO ^ + 7.5% Na + 3% Na. This catalyst is tested in a pilot plant and the change in product material composition of the feed stream entering and exiting the reduction catalyst is specially evaluated.

The reactor used contained an oxidative dehydrogenation catalyst and then the acetylene reduction catalyst. The two layers are essentially through one inert layer separated from AMC. The LHSV (Liquid Hourly Space Velocity) of the stream is measured during the Trial duration varies to make certain observations, but all the time it is between 2.0 and 3.0. That

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Steam to hydrocarbon molar ratio is at that Trial 12.0. The steam-to-oxygen ratio is at the experiment-24 + 0.7 * -md the oxygen-to-n-butene molar ratio in the experiment is 0.52. The LHSV in the attempt is given in the following table.

LHSV Ongoing Trial

hours

2.49. 1 - 335

2.00 335 "- 401

2.49 401-446

3.00 446-572 2.00. 572-671

2.49 671-812

3.00 812-921

2.00 921-992

2.49. 992-1141

2.00 1141-1448

The acetylene catalyst feed contains butadiene, n-butenes, COp, CO and trace amounts of acetylenes and carbonyls. The purpose of this attempt is to identify any disadvantages that the catalyst may have on the butadiene product and unreacted n-butenes to be determined. The averages are probably much more meaningful than the special time information, since they are the same as in actual proceedings the numerical values vary considerably with the individual readings, for example a loss of butadienes and indicate some increase. The average values indicate a small loss of hydrocarbons that can be achieved expected. During these tests, the spot analysis (so-called spot analysis) shows the acetylene and carbonyl contents a substantial reduction in both connections. The values for acetylene and carbonyl removal were not necessarily determined by the same samples but within the same time span. The results show that continuous effectiveness of the catalyst.

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During the course of a 1448 hour test, the following were carried out _: 89 separate determinations of the material content of C ^ compounds over the acetylene reduction catalyst. Strong variations have been observed in the different samples which can be assumed to be actual variations, or which can be viewed as a result of the change in chromatographic analyzes, or by both. The results reported are the cumulative averages of the changes in the content of the stream after it was passed over the acetylene reduction catalyst. The results are reported in C ^ equivalents / 100 moles of C »feed. The experiment was terminated because a fall occurred in the acetylene reduction. When the acetylene removing catalyst was examined, it was found that the upper part was fused or sintered. It was found that apparently water had flowed onto the catalyst.

Durchschnitti.Änderung in the stream after passage over the g \ catalyst LVU N ° hours samples C ^ -Äquiv. / IOO mol C "-Beschick.

in _De i d.av. ■ material

drove determination CO CO ₂ C ^ butadiene

0-513 37 -0.163 0.873 -0.209 -0.411

513-1448 52 -0.082 0.874 0.095 -0.829

0-1448 89 -0.116 0.874-0.031 -0.656

A measurement above and below the catalytic converter for the Reduction of the acetylenic compounds is considered a sample.

It can be seen that there are no signs of dehydration, since the butadiene content shows a slight decrease.

Chromatographic analysis shows the reduction in Impurities as follows:

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Mole percent removal 840 h 600 hours 100 99 86 90 85 88 75 60

formaldehyde
Vinyl acetylene
acetaldehyde
Acrolein

Example 14

Simultaneously with the large-scale experiment, a semi-industrial experiment was carried out according to the procedure of the examples 1 to 8 carried out with the same catalyst. No time influence was noticed after 60 days in operation. The impurity removal from a C ^ stream, similar as used in Example 11 shows:

Mon 1-94 reduction

Formaldehyde ■ 100

Vinyl acetylene 90

Acetaldehyde '93

Acrolein 85

Example 15

A catalyst composition was prepared from Fe-O ,, BaCO ₇ ,, NiCO * and NaOH, and the catalyst was tested for removal of acetylenes according to the following procedure.

Catalyst components kg (lbs) corrected Fe ₂ O ₃ (87 ° / o) 31.9 (70.27) = 27.8 (61.4)

BaCO ₅ 4.62 (10.19) 4.62 (10.19)

NaOH 4.84 (10.68) 2.9 (6.4) (Na)

NiCO ₃ 4.02 (8.86) 1.8 (4.0) (Ni)

All solids were measured in a mill and then placed in a liquid-solid mixer and the NaOH solution was added to this. The mixture was dried and pelletized (0.24 cm = 3/32 inch pellets.)

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Essentially the same reactor and charging procedure were used as in Examples 1 to 8, The catalyst had the following composition:

6: 1 Fe ₂ O ₃ / BaCO ₃

6.65% Na (analysis)
4.35% Ni (analysis)

The following results were obtained;

ffi reduction

Formaldehyde 99

Acetaldehyde 88

Acrolein 70

Vinyl acetylene 88

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Claims (1)

- 26 claims 1. Process for the treatment of a stream of organic compounds in vapor phase at a temperature of at least 250 ^° C., which contains less than 5 mol% of free oxygen and a small amount of acetylenic compounds, with a catalyst in order to increase the amount of acetylenic compounds reduce, characterized in that the catalyst as main cation elements, based on weight, at least Fe and Ni and a metal such as an element of groups 8, 1b, 2b, 4b, 6b and 7b of the periodic table, an alkaline earth metal of group 2a of the periodic table and contains an alkali metal of group 1a of the periodic table. 2. The method according to claim 1, characterized in that the stream mainly contains hydrocarbons. 3. The method according to claim 2, characterized in that that the material containing at least Pe and Ni is Fe, Ni, Cr, Mn, Cu, Zn or Zr, that the alkaline earth metal is Mg, Ca, Sr or Ba and that the alkali metal is Li, Na, K or Rb. 4. The method according to claim 3 »characterized in that the material containing at least Fe and Ni, also Contains Zn. 5. The method according to claim 4, characterized in that that the catalyst contains a metal ferrite. 6. The method according to claim 5, characterized in that zinc ferrite is used as the metal ferrite and that Ba
and Na are present in the catalyst. 7 * The method according to claim 6, characterized in that the main amount of hydrocarbons in the hydrocarbon stream contains η-butene and butadiene. 509834/1012 8. The method according to claim J5> characterized in that that the hydrocarbons contain 2 to 8 carbon atoms. 9. The method according to claim 8, characterized in that the hydrocarbons contain 4 to 6 carbon atoms 10. Vapor phase process for the production of unsaturated hydrocarbons, comprising the oxidative dehydrogenation of a stream of hydrocarbon compounds to produce a product stream with a major amount of hydrocarbon product and a small amount of acetylenic compound as an impurity, characterized in that the product stream, which is less than 5 moles - Contains free oxygen, is treated in the vapor phase at a temperature in the range from 250 to 900 ⁰ C with a solid catalyst for the reduction of the acetylenic compounds in the product stream, the catalyst containing a material as the main cation elements, expressed by weight which contains at least Fe and Ni and a metal selected from the elements of groups 8, 1b, 2b, 4b, 6b and 7b of the periodic table, an alkaline earth metal of group 2a of the periodic table and an alkali metal of group 1a of the periodic table. 11. The method according to claim 10, characterized in that the material containing at least Fe and Ni, Fe, Ni, -Cr, Mn, Cu, Zn or Zr is that the alkaline earth metal is Mg, Ca, Sr or Ba and the alkali metal is Li, N, K or Rb. 12. The method according to claim 11, characterized in that the catalyst contains a zinc ferrite and that Ba and Na are present in the catalyst and that the majority of hydrocarbons in the hydrocarbon stream η-butene and Butadiene is. 13 · Catalyst for reducing the amount of'acetylenic Compounds in a stream of organic compounds containing a material containing at least Fe and Ni and an EIe- 609834/1012 2 * 61025 ment of groups 8, 1b, 2b, 4b, 6b and 7b of the periodic table, an alkaline earth metal of group 2a of the periodic table and contains an alkali metal of group 1a of the periodic table. 14. Catalyst according to claim 13, characterized in that that the material containing at least Fe and Ni is Fe, Ni, Cr, Mn, Cu, Zn or Zr, that the alkaline earth metal is Mg, Ca, Sr or Ba and that the alkali metal is Li, Na, K or Rb. 15 ♦ Catalyst according to claim 14, characterized in that that the material containing Fe and Ni also contains Zn. 16. Catalyst according to claim 15, characterized in that it contains a metal ferrite. 17. Catalyst according to claim 16, characterized in that that the metal ferrite is zinc ferrite; and that Ba and Na are present in the catalyst. 18. Catalyst according to claim 13 to 17, characterized in that the nickel in a range from 0.25 to 20% by weight, based on the total weight of the catalyst, is present. 509S34 / 1012