DD208345A5 - METHOD FOR SELECTIVELY CUTTING A POLYALKYLENE GLYCOL - Google Patents

Abstract

The object of the invention is to provide an improved process which is applicable on an industrial scale. According to the invention, a method is provided for the selective cleavage of a polyalkylene glycols containing at least one ether group, e.g. Diethylene glycol at a covalent carbon-to-oxygen bond and independently at a carbon-to-carbon covalent bond by heating the polyalkylene glycol with molecular hydrogen in the presence of a nickel-containing hydrogenation catalyst to obtain at least one of monoethylene glycol monomethyl ether, monoethylene glycol and. Ethanol. When using the process according to the invention, monoethylene glycol monomethyl ether can be produced in predominant amounts.

Description

L · 4 H 3 9 2 / ~ ^A ~~ Berlin, 09.06.1983

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Process for the selective cleavage of a polyalkylene glycol

Application s field of the invention

The invention relates to a process for the selective cleavage of a polyalkylene glycol,

Characteristic of the known technical solutions .

As is well known, monoethylene glycol is produced industrially by the hydrolysis of ethylene oxide, which in turn is produced by the oxidation of ethylene _f, typically by the reaction of ethylene and oxygen but a silver-containing catalyst. Other (non-industrial) methods of producing monoethylene glycol include reactions of carbon monoside with hydrogen or formaldehyde. typically in the presence of a particular noble metal catalyst * main by-products of the industrial oxide / glycol process are diethylene glycol and higher polyalkylene glycols in amounts of up to xs 10% by mass of the total product mixture, "Nan would not necessarily be an industrially desirable by-product"

Thus, for example, in the industrial Osid / glycol process, considerably more diethylene glycol by-product can be produced than is profitable to use. In those instances where the production of diethylene glycol is industrially undesirable, any high process solution which would be desirable in the art would be able to convert this product effectively raising au-Monoethylenglvkol Monoraethylether _s Monoethyls> glykolj ethanol or other valuable products "

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As a result of the present invention, it has been shown that polyalkylene glycols, such as diethylene glycol, can be monoethyleneglycol monomethyl ether monoethylene glycol and ethanol attached to a covalent carbon-su-oxygen bond, and independently to a covalent alcohol, to efficiently produce at least one of the compounds Carbon bond can be selectively cleaved by heating the polyalkylene glycol with molecular hydrogen in the presence of a nickel-containing hydrogenation catalyst. "

The following prior art references describe processes involving hydrogenolysis or molecular hydrogen cleavage in the presence of a hydrogenation catalyst.

The JP-OS Ur. 25,246 / 74 describes the selective splitting of polyalkylene glycols as s. 3 »· Diethyleiigiykol and polyalkylene glycol monoalkyl ethers on a kovaienten carbon to carbon bond by heating with molecular hydrogen in the presence of a nickel or palladium catalyst for the purpose of providing alkylene glycol Honoalkylethernj 'polyalkylene glycol Monoalkylethernj alkylene glycol dialkyl ethers and polyalkylene glycol dialkyl ethers, from Monoethyleneglycol, p-methyl ether and methane are reported in this context to be produced longitudinally by this gap. "This patent, however, does not disclose bsv / _e as a result of the co-production of ethanol as a result of the hydrogenolysis of a polyalkylene glycol.

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The DS-PS Hr. 2,900,279 describes the selective splitting of polyalkylene glycols such as. Of diethylene glycol or monoethylene glycol mono mono or monoaryl ethers including their homologues on a covalent carbon-to-carbon bond with molecular hydrogen in the presence of a catalyst consisting of a carrier, wherein on this carrier at least one of the elements palladium, platinum, ruthenium, Rhodium or iridium is applied in the form of a compound to provide in this way dimethyl ether, methyl alkyl ether or methyl aryl ether. If a polyalkylene glycol is used as starting reactant, its terminal Hydroxymethy! Groups are cleaved to form the dimethyl ether of a glycol, according to the statements of this patent, monoethylene glycol and ethanol from the hydrogenolysis of a polyalkylene glycol are not produced.

FR-PS 2,447,363 describes the selective cleavage of polyalkylglycol-monalkylalkylated covalent carbon-to-oxygen bonds with molecular hydrogen in the presence of a nickel and barium catalyst for the purpose of providing alkylene glycol monoalkyl ethers and polyalkylene glycol monoalkyl ethers For example, diethylene glycol monoethyl ether is cleaved to give monoethylene glycol monoethyl ether. If the hydrogenolysis of the polyalkylglycol monoalkyl ethers does not proceed completely, then small amounts of ethanol can be detected in the reaction mixture Hydrogenolysis of a polyalkylene glycols for the production of both monoethylene glycol and ethanol »

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The US-Ir. 3,833-634 describes a process for the preparation of polyfunctional oxygen-containing compounds such as ethylene glycol and / or its derivatives by reacting a Sohlenstoff ox ids with hydrogen using a rhodium complex catalyst in combination with carbon monoxide at elevated temperature and elevated pressure "The Ausführungsbeiapiel 23 describes the production of ethylene glycol by hydrogenolysis of open-chain glycol ethers, such as Z ₉ B _fl of tetraethylene glycol dimethyl ether,

JP-OS Ir * 109 * 908/79 describes the selective cleavage of an alkylene oxide V7ie a, 3, of ethylene oxide with molecular hydrogen in the presence of a hydrogenation catalyst and a low polarity solvent. The reaction is carried out in the IPliissigphase to alkylene glycol alkyl ethers such as monoethylene glycol monoethyl ether. Ethanol is produced as a by-product. This patent does not describe the hydrogenolysis of a polyalkylene glycol for the preparation of monoethyl glycol monosiethyl ether, monoethyl glycol, and ethanol.

US Pat. No. 1,953,548 describes a process for obtaining n-propyl alcohol ₅ in which propylene oxide vapor at elevated temperature is swept over an aluminum-containing contact catalyst and this vapor immediately thereafter is in the presence of hydrogen passing over a hydrogenation catalyst containing reduced nickel *

US Pat. No. 3,975,5449 describes a hyarogenolysis process for obtaining a primary diol and / or triol

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an eposid wherein the epoxide is contacted at elevated temperature and pressure with molecular hydrogen and a gum or cobalt-containing gum catalyst.

Davidova and Kraus, Journal of Catalysis , JS ^, 1-6 (1980) describe the cleavage of 1,2-BpOSybutane with molecular hydrogen in the presence of a platinum supported catalyst at elevated temperature and elevated atmospheric pressure to obtain oxidized products such as 2 Butanone _? 1-butanol and 2-butanol *

The DE-PS 2,434 »Q57 describes a Hydrogenolyee method for threaded n ung of Glykoldimetnvlethern means of cleavage of the portals of the corresponding glycol monomethyl ether, with molecular hydrogen in the presence of catalysts composed of Osidgeoiischen of silicon and aluminum and / or rare earths, and -additional ' the metals nickel, cobalt or copper.

DE-PS 2 * 716,690 describes a Hydrogenolyseeerfahren for obtaining Glykoldiiaethylethern means of cleavage of the Pormale of the corresponding glycol monomethyl ether with molecular hydrogen in the presence of catalysts consisting of oxide mixtures of silicone and aluminum and / or rare earths as well as of -metallic JT ick el and / or cobalt and / or copper, these catalysts being characterized by the fact that they additionally contain metallic palladium and / or rhodium and / or platinum as promoter.

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Nevertheless, we are currently aware of these references, or to our knowledge of the prior art, no disclosure of a process involving the cleavage of a polyalkylene glycol at a covalent carbon-to-oxygen bond and independently at a covalent carbon-to-oxygen bond. Carbon bond by heating with molecular hydrogen in the presence of a nickel-containing hydrogenation catalyst to produce in this way at least one of the compounds monoethylene glycol monoethyl ether ₅ monoethylene glycol and ethanol.

Aim of the invention

The aim of the invention is to provide an improved process for the cleavage of polyalkylan-glycols, with de ca in 'industrial scale with high reaction rate Monoethylenglykol Mononiethylether, monoethylene glycol and ethanol can be obtained in good yield, ..

Explanation of the essence of the invention

The invention has for its object to carry out the selective cleavage of Polyalkyienglykolen at a suitable location and to use a suitable catalyst for it *

The present invention provides a process for the selective cleavage of a polyalkylene glycol such as ξ " B * diethylene glycol having at least one ether group contained therein at a kevalent Schienstoff-to-3-oxygen bond and independently of a covalent Schlammstoff-to-Xohlenstoff-Bindüng by Heating the polyalkylene glycol with molecular hydrogen in the presence of a nickel-containing hydrogenation catalyst zv ^ ecks Gewinn'ong at least one of

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Compounds monoethylene glycol monomethyl ether, ethylene glycol and stanol "

By applying the process according to the invention, monoethylene glycol monomethyl ether can be produced in predominant amounts; d. The selectivity of monoethylated glycol monomethyl ether can reach about 95 mole percent.

The co-pending and commonly assigned United States Patent Application Serial No. (D-13,231) discloses the preparation of monoethyl glycol and ethanol by the hydrogenolysis of a polyalkylene glycol such as diethylene glycol. Daa polyalkylene glycol is cleaved at a carbon-to-oxygen covalent bond by heating with molecular hydrogen in the presence of a hydrogenation catalyst, such as copper cholorite, to thereby produce at least one of monoethylglycol and ethanol. The selectivity of monoethyiene glycol and ethanol can reach or even exceed 95 mole percent when copper chromite is used as the hydrogenation catalyst. "

As a result of the present invention, it has surprisingly been found that when a nickel-containing composition is used as the hydrogenation catalyst in a process for the hydrogenolysis of polyalkylene glycols, both monoethyl glycol and ethanol are produced and "monoethylene glycol monosiethyl ether is additionally produced in a selectivity Accordingly, it is readily apparent that by means of similar hydrogenolysis processes using either a nickel-containing hydrogenation catalyst or a hydrogenation catalyst such as

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For example, copper chromite either monoethylene glycol monomethyl ether monoethylene glycol ethanol or monoethylene glycol stanol can be selectively prepared. The selectivity of Monoethylenglykol ^ Monooiethylether in the present invention, as well as the selectivity of monoethylene glycol-ethanol in the co-pending US patent application serial number (D-13 * 231) can each achieve '95 mole percent'

The simultaneously registered and with the same. Datuni registered U.S. Patent Application Serial No. (D-13 341) describes a process for selective cleavage of a PoIyalkylenglykola such _e B "Disthylenglykol of a covalent carbon-sa-oxygen Bindong as well as regardless of a covalent carbon-to-iCohlenstoff- Bond by heating ax molecular. Hydrogen in the presence of a Rutheniumhaitigen hydrogenation catalyst, including in this way at least one of the compounds monoethylene glycol monomethyl ether ₃ Monoethylenglykol and ethanol to produce The production rate of each of said monoethylene glycol MonoinethyletherSj Monoethylaaglykol3 and ethanol is at least ens about 10 mol / kg ruthenium / hour _β

US Pat. Appln. Serial Numiner (D-13 »342), registered on the same date and registered with the same date, describes a process for the selective cleavage of a polyalkylene glycol such as 2'3, diethylene glycol on a covalent carbon-to-oxygen bond! U2g and independently of which at a covalent-carbon-to-carbon bond by heating with molecular hydrogen in the presence of an iri.

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Dihydrogenated Hydrogenation Analyzer to Produce at Least One Yield of Monoethylene Glycol Monoethyl Ether, Monomethylenglycol Mononiethyl Ether, Monoethylene Glycol, and Ethanol "Monoethylene glycol monoethyl ether can be prepared in substantial amounts by use of the process disclosed in this co-pending application."

The hydrogenolysis of polyalkylene glycols can proceed through various cleavage pathways. For example, as illustrated in the present invention, the polyalkylene glycols can be attached either to a covalent carbon-to-nitrogen bond or to a covalent carbon-to-carbon bond be split to provide different products. The cleavage pathways are influenced or varied to some extent by the hydrogenation catalyst's Walil, the concentration of active metal in the hydrogenation catalyst, the pressure imposed by the molecular "hydrogen, and other factors" of the preferred embodiment of the present invention for the hydrogenolysis of a polyalkylene glycol for example, if a nickel-containing hydrogenation catalyst is used by diethylene glycol, then the cleavage pathway is predominantly directed to a covalent carbon-to-carbon charge, which results in the production of monoethyleneglycol mononiethyl ether in predominant amounts. "A lower cleavage fraction is attributable to a carbon-to-carbon charge. Oxygen covalently bonded, resulting in a production of both monoethylene glycol and ethanol in smaller quantities result in the 'most' preferred embodiment of the inventive method, therefore, the hydrogenation catalyst at least contain about 65% by weight of nickel in order to obtain desirable amounts of mono-

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to win ethylene glycol monomethyl ether, monoethylene glycol and ethanol; d _e h h »the selectivity of monoethylene glycol monomethyl ether can reach about 95 mole percent *

The preferred hydrogenation catalysts useful in catalyzing the hydrogenolysis process of this invention are well known in the art and include nickel-containing compositions. The preferred hydrogenation catalysts may also contain as an additional ingredient one or more accelerators to enhance the activity of the hydrogenation catalysts. Suitable catalyst accelerators may include barium, calcium _s magnesium, manganese, Strontium, zirconium, titanium, hafnium, potassium, lithium, sodium, rubidium, cesium, molybdenum, chromium, tungsten, zinc and the like. Certain metals such as copper, chromium, molybdenum, tungsten, iron, cobalt, ruthenium, rhodium, palladium, platinum, iridium, rhenium, tantalum, vanadium, iJiob *, zinc, and the like can act as cocatalysts in combination with nickel. It should be noted that; Molybdenum, chromium, tungsten and zinc can act either as a cocatalyst or as a promoter. The sizing of the above metals as hydrogenation catalysts, promoters or cocatalysts relates both to the compound form of the metal and to the elemental form, for example, al3o Metal oxide or sulfide or a metal hydride, or else the reduced metal form or mixtures of the aforementioned forms. The hydrogenation catalysts may be used in the presence or absence of a catalyst carrier. Suitable excipients include silica gel, alumina, magnesia, titania, magnesia, zirconia, oilikonkarbid, ceramics, pumice, carbon, diatomaceous earth, kieselguhr, and the like "Characteristic of the preferred, in particular, erfinaurLgs-

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Hydrogenation catalysts useful in conventional processes are compositions having at least about 10 weight percent nickel on a suitable catalyst support, for example, silica gel, nickel diatomaceous earth, and the like. The oxide-containing compositions may be fully or partially reduced in-situ during "heating of the reactor." The most preferred hydrogenation catalysts of the present invention include compositions containing at least about 65% by weight of nickel on a suitable catalyst carrier. Many of the hydrogenation catalysts described above are commercially available, others are prepared by known methods as outlined below. "

The hydrogenation catalysts useful in the process of the present invention may be employed in any form, may be in the reaction state in the form of finely divided powders, porous tablets, pellets, spheres, granules, and the like. It is desirable that the hydrogenation catalysts have an extended surface area.

The preferred surfaces range from about 0.5 a / g

up to about 300 m / g and above. In. In the most preferred variant, the surface area of the hydrogenation catalyst is sufficient

2 2

From about 10 m / g to etv / a 300 a / g "The average pore diameter of the hydrogenation catalysts is not critical. · For catalysts with very small pores, the hydrogen diffusion rate formation is likely to be" ss Mean pore diameter and / or a large catalyst particle diameter detrimental ZBinfluß with respect to high Monoethylengiykol monomethyl ether monoethylene glycol ethanol selectivities and / or Polyallylenglykol üawand-

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lungs rates exercise "In general, for obtaining desirable monoethylene glycol monomethyl ether-monoethylene glycol-Bthanol selectivities in the inventive Hydrogenoiyseeerfahren catalysts having an average Poraadorchmesser von.mindestens about 150 A ^0, preferably at least about 250 Δ, and a particle diameter of less than 10 EIH - preferably 5 mm or even below - considered suitable »

The quantity of the hydrogenation catalyst used is not critical and can vary over a wide range. In general, the process according to the invention is carried out either by the flow through principle or batchwise in the presence of a catalytically effective amount of the hydrogenation catalyst which ensures a suitable and suitable reaction rate "This is a reaction rate of, for example, from about 1 to about 100 moles / kg of catalyst / hour." The reaction proceeds, even then , no more than about 0.01 mass percent, or even a lesser amount The upper concentration of hydrogenation catalyst can be quite high, for example about 50% by weight based on the total amount of reaction mixture However, the upper concentration appears to be determined by economic considerations regarding the cost of certain hydrogenation catalysts for the reaction of the reaction mixture as well as the manageability of the reaction mixture in the course of the reaction depending on the seed operating pressure of the system, the operating tempera-

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In general, a concentration of between about 0.1 and about 30 percent by weight of hydrogenation catalyst, based on the total amount of the reaction mixture, is suitable in the practice of the invention.

The polyalkylene glycols to be preferably employed in the practice of the process of the present invention are well known in the art, including diethylene glycol, triethylene glycol, tetraethylene glycol, etc. In the most preferred embodiment of the present invention, diethylene glycol, which is a by-product of the industrial grade described above, is used. Glycol process was selectively cleaved at a covalent carbon-to-oxygen bond as well as independently at a covalent bond-breaking bond by heating with molecular hydrogen in the presence of a nickel-containing hydrogenation catalyst in order to By use of the preferred catalysts and reaction conditions of the present invention, higher polyalkylene glycols such as triethylene glycol and tetraethylene glycol can be prepared ykoi selectively cleaved to produce in this way at least one of monoethyene glycol monomethyl ether, monoethylene glycol and ethanol. These polyalkylene glycols are prepared by methods well known in the art.

The initially present in the relative amounts of Reaktionagemisch Polyalkyienglykol and molecular hydrogen can 'but a wide range of time can be varied. "In general, the molar ratio of molecular hydrogen to Polyalkylenglyiol is in the range between about 1:20 and

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about 2000: 1, preferably between about 1: 2 and about 500: 1 and in the most preferred variant between 1: 1 and about 200: 1, but Ea is self-evident, that also molar ratios outside of this broad range indicated However, very high molecular ratios of molecular hydrogen to polyalkylene glycol are economically unattractive, and very low molar ratios of molecular hydrogen to polyalkylene glycol will generally have low conversion rates as well as lower product selectivities of Polge when operating the continuous flow method For example, molecular hydrogen and polyalkylene glycol can be fed either in parallel or in countercurrent via the hydrogenation catalyst, with either upflow, downflow or horizontal flow being selectable; preferably, a downward countercurrent. »The gas hourly gas velocity (GHSV) of the molecular hydrogen and the hourly liquid volatility (LESV) of the polyalkylene glycol can be varied over a wide range in a continuous process.« The hourly gas-space velocity of molecular hydrogen can be varied from approx

- 1 -1

100 hours or less to more than 100,000 hours; preferably, it ranges from about 1000 h 'to about 100

- 1 -1

h ~ ° 3, and most preferably, it ranges from about 2,000 h

up to about 75,000 hours "" The liquid hourly liquid velocity of poly (alkylene glycol) may range from about 0 "_3" hours or less to about 100 hours or more;

- 1 -1

Preferably, it ranges from about 0.1 h to about 25 h;

in the most preferred variant, it ranges from about 0.25 h "" ¹ to below about 10 h "* ^'1 · The higher GH3V- and LHSV values generally result in the tendency to uneconomical

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The GHSV and LHSV values tend to reduce the selectivity of monoethylene glycol monomethyl ether, monoethylene glycol, and ethanol. The intended purpose is to provide a sufficient amount of polyalkylene glycol and molecular hydrogen in the reaction mixture to realize the desired production of monoethylene glycol mono-methyl ether, monoethylene glycol and ethanol.

The inventive process can run through a Yfeiten temperature range hinvyeg v / ground * In general, the process is at a temperature between about 125 ⁰ C and about 350 C performed Lower temperatures generally cause an improved product selectivity, but often at economically unfavorable rates ;. Higher temperatures generally increase overall productivity, but also involve the tendency of increased by-product formation. Operating the process at temperatures below 125 ^° C. will not result in recovery of the desired products at the optimum rate, so that the reaction usually exceeds * For a prolonged period of time and / or using excessively enhanced catalase levels, it is necessary to obtain the desired level of reaction products at reasonable rates. * Driving the process at temperatures well above 350 G is apt to cause the decomposition of the organic contained in the reaction mixture Substances "When driving at the lower end of the temperature range, it is desirable in most cases to choose pressures from the upper third of the pressure range. The preferred temperature range is between about 150 ^° C. and 300 ^° C., with the most preferred temperature range between about 175 ^° C. and 265 ^° C. reading.

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There are Allerding also occasions where the preferred temperature range can be located both in the more common Tempersturregionen and within the breitesten range, so that the process both Temperaturen'zwischen 150 ⁰ G and 300 ⁰ G, as well as between 125 ⁰ G and 325 ⁰ C. can be operated.

The process according to the invention is carried out under atmospheric or superatmospheric pressure conditions. In a preferred embodiment of the present invention, the pressure is generated almost exclusively by the molecular hydrogen shown in the reaction. However, suitable reactionless gaseous diluents can also be used if required. Actual operating pressures (initial pressures under conditions batch operation) at between about atmospheric pressure and about 10,000 psig (700 at) provide an operating limit for the production of the monoethylene glycol-mcnomethyl ether, monoethylene glycol, and ethanol products. The preferred actual operating pressure conditions for producing monoethylene glycol. Monomethyl ether, monoethylene glycol, and ethanol ranging from about 100 psig to about 4,000 psig (7 to 280 at); in the most preferred variant, they range from about 250 psig to about 2,000 psig (18 to 140 at). As the process progresses at lower pressures, the rate of reaction slows down, and therefore the reaction time must be increased until the desired amount of reaction product is generated. When driving the process at higher pressures, the rate of production of desired products is generally increased. Higher pressures generally increase the selectivity of methylene glycol.

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Monomethyl ethers, very high pressures, can also increase the production of lifting product through secondary hydrogenolysis reactions. Lower pressures generally tend to increase the selectivity of mocnoethylene glycol and ethanol, and increase the formation of IT b products such as 2 -Q2odioxan and reduce the selectivity of monoethylene glycol monomethyl ether.

The process of the present invention is carried out for a time sufficient to produce the desired monoethylene glycol monomethyl ether, monoethylene glycol and ethanol products. In general, the reaction time can range from a fraction of a second to several hours, d * h, from 0 _s 1 s and short to about 10 hours and longer. If slower reaction conditions are chosen, then the reaction time must be extended until the desired products are prepared. It is readily apparent that the required residence time, ie the reaction time, the influence of the reaction temperature, the concentration and choice of the hydrogenation catalyst, the total pressure, the concentration ( molar ratio) of polyalkylene glycol and molecular hydrogen and other factors. If the hydrogenolysis process according to the invention is carried out in a continuous process, the reaction time or residence time should generally be from a fraction of a second to several minutes or longer, whereas the residence time under gaseous conditions is generally The synthesis of the desired products from the hydrogenolysis of a polyalkylene glycol is more suitably carried out under operating conditions requiring adequate reaction rates windiness and / or conversion

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provide long.

The process according to the invention may be carried out batchwise or else in a semi-continuous or continuous manner in either a liquid phase, a vapor phase or a combined liquid phase. The reaction may be carried out in sludge bed, sludge phase, trickle bed or silt bed Reactors or the like may be used in a single reaction zone or in a series or parallel plurality of reaction zones. The reaction may further be carried out intermittently or continuously in an elongated tubular zone or in a row arrangement of such zones. The equipment required to carry out the reaction should be made of a material which remains inactive during the reaction. The equipment should also be able to cope with the reaction temperatures and pressures: The reaction zone may be equipped with internal and / or external heat exchangers to control unfavorable temperature fluctuations caused by the moderate esothermal nature of the reaction. In a preferred embodiment of the invention Stirrers to ensure a complete.Mixing of the reaction mixture should be used in Reaktionsssvstemen that work without Pest.bett catalyst "is characteristic in this sense, a mixing means of magnetic stirrer, shaking, vibration, panning, over-tamping with gas, swinging etc. Such stirring devices are available and well known in the art.

The Polyaikv.lenglykol, the molecular hydrogen and the

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Alternatively, the polyalkylene glycol, molecular hydrogen, and hydrogenation component components may be introduced into the reaction zone continuously or intermittently during the course of the synthesis reaction. Within the process, means for introducing the components into the reaction zone may be included the reaction zone during the course of the reaction and / or auxiliaries for adjusting the constituents in the reaction zone during the course of the reaction, either intermittently or continuously in a conventional manner, to maintain the desired molar ratios of the constituents to each other as well as the pressure exerted by the hydrogen,

The operating conditions of the present process may be adjusted to optimize the selectivities and conversion rates of the desired products and / or the economy characteristics of the process. For example, it is generally preferred to run at relatively low conversion rates, as these tend to have increased selectivities of monoethylene glycol monoethyl ether, monoethylene glycol and ethanol due to reduced heel product formation. Lower conversions also tend to increase the molar ratio of monoethylene glycol to ethanol by causing secondary hydrogenolysis reduce monoethylene glycol "the representation of the desired monoethylene glycol MonomethyletherSs Monoethylenglykol3 and .Ethanola _s can be done so as by distillation through specialized in known methods! fractionation, extraction and the like" Typically, could in the implementation of the method, the reaction

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mixture contained product are removed from the reaction zone and distilled to obtain the desired products. For reactors that do not use a fixed bed catalyst, a fraction containing the hydrogenation catalyst and by-products may be removed for recovery or regeneration of the catalyst. Fresh hydrogenation catalyst can be added to the reactor stream at intervals to replace any lost catalyst in the process. "

While the present invention has been described in terms of a number of details, it is not intended to limit the invention in this way.

The following embodiments are merely illustrative of embodiments of the invention so far explored; it is by no means intended to limit the scope and intent of the invention in any way whatsoever.

Exemplary embodiments

In the following examples, the following definitions, terms and abbreviations apply:

psig ; Pounds per square inch gauge pressure, U / Bin ^ revolutions per minute, k_g; Kilogram.

lbs: pound ft. foot

Kat .; catalyst

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Ueiw »: Conversion Hi hour cm cc mV square meters

£ ^ grams

DSG; Diethvlenglykol

GHSY: Hourly gas space velocity

LHSY; Hourly Plüssigkeits-Raumgeschv / indiglceit -

h ~ " ; reciprocal hour unit for GHSY and LHSY

% or percent : trade fair percent unless otherwise specified,

Yerhältnisangaben; On a fair basis, if not otherwise

specifies "

temperatures; Data in degrees Celsius, unless otherwise specified «

'3 "Di Eicht proved

Selectivity ^ Calculated by the Pornier

^ s 100 % selectivity i =

_ηΤ ρ Umw,

where i is the individual component, d * h * monoethylene glycol monomethyl ethers, monoethylene glycol, ethanol or by-products and where r is the rate in KoI / kg cat, / h.

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The catalysts used in the embodiments are indentified as follows;

Catalyst I, Sine 35% by mass "

sanunensetzung with a surface area of 165 ni ~ / g, a bulk density of 61 lbs _e / Kubikfluß (977 kg / m ^J) m a compressive strength of 30 lbs (13.6. kg), a particle size of 3 / Ί6 inches (4, 8 mm) and a pore volume of 0.39 cm / g,

Catalyst II, containing 50% by weight of nickel

Composition having a surface area of 150 m / g, a bulk density of 45 lbs * / cubic foot (720 kg / m- ⁵ ), a compressive strength of 18 pounds (8.2 kg), a particle size of 1/16 inch (1.6 mm ) and a pore volume of 0.50 carVg * -

Catalyst III . Sine containing 65% by weight of nickel

2 Composition with a surface area of 125 m / g, one

• 3

Bulk density of 63 lbs Kübikfuß 1009 kg / m, a compressive strength of 15 lbs. "(6.8 kg) of a particle size of 3/16 inches (4.8 mm) and a pore volume of 0.45 carVg,

Catalyst Γ7 «. Composition containing 65% by mass with a surface area of 145 si / g, a bulk density of 76 lbs ₉ / lbs. (1 218 kg / m), one. Pressure resistant gceit of 16 lbs (7.3 kg) of particle size 3/16 inch (4.8 mm) and pore volume of 0.36 ca ^; _ä

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Catalyst y. A composition containing 10% by weight of silica gel on the catalyst has a surface area of 275 ai / g, a particle mass of 25 lbs./ cubic feet (400 kg / a -1), a particle size in the powder range after grinding and a pore volume of 1.2 cm / g.

Catalyst 71 A composition containing 10% by weight of Ilickel and 0.5% by weight of calcium on silica gel, the catalyst has a surface area of 275 m / g,

a mass of 25 lbs./cubic feet, (400 kg / m) a particle size after grinding in the powder range, as well as

• 3

a pore volume of 1.2 cm / g »

Catalyst VII " Sine 10% by weight composition containing silica gel; the catalyst has a

O surface of 275 m / g, a Raununasse of 25 lbs./Kubikfuß (400 kg / m), after grinding a particle size in PuI range and a pore volume of 1.2 cm / g on.

Catalysts V and VII were prepared using a variety of methods to be described in more detail below

Commercially available catalysts, d. h "the catalysts I to IV were used in the exemplary embodiments in the Porm, as it was after delivery by the manufacturer» In the Ausführungsbeispisien carried out under batch conditions, the pelletized catalyst versions were first pulverized with mortar and pestle until each catalyst you one of the 200 mesh could happen. In the run conditions

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The catalyst particles were used after receipt of the. First crushed the producer and then sieved it to a mesh size of 8 to 20 "

The catalysts V, VI and ViI were prepared in the laboratory according to the following general procedure:

The silica gel carrier prewashed to reduce impurities with hot gum acid solution was impregnated under vacuum with an aqueous solution of the appropriate catalyst precursor listed in Table A below. The volume of solution was just sufficient to fill the pore volumes. The salt concentration was adjusted to give the desired weight percentage in the finished catalyst * after standing at room temperature for 30 minutes, the impregnated carrier was dried in stages as follows; for one hour at 35 G, for two hours at 110 C, for two hours at 150 ⁰ C and for two hours at 200 ⁰ Gj the soaked carrier of the catalysts VI and VII was dried in the following stages: one hour at 85 ⁰ C, for two hours at 110 ⁰ G, for 3 hours at 150 ⁰ C, The dried material was transferred to a quartz tube and by heating to tnasinial 400 ⁰ G (catalyst V) or 500 ⁰ C (catalysts VI and VIl) at a Rate of 100 ⁰ G per hour under running. Hydrogen reduced "The temperature was held at maximum temperature for one hour, then the system was cooled in hydrogen to SO". The hydrogen was nitrogen-cycled and the catalyst was cooled to room temperature. "

2443

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AP.G 07 G / 244 (61 497/12)

Table A

Catalyst Labeling Catalyst Precursor V Ui

VI STi (EfO ₂ ) ₂ , Ca (10O ₃ ) ₂ ,

VII Hi (SO ^) ₂

Exemplary embodiments 1 to 18

Embodiments 1 to 18 were carried out batchwise in a 300-oil stainless steel autoclave reactor equipped with a magnetic stirrer according to the following procedure. Prior to each embodiment, the magnetic guide was removed and thoroughly washed in order to remove any remaining catalyst powder in all its parts. All parts and internals of the reactor were similarly cleaned, rinsed with acetone and dried. The reactor was then charged with a mixture of 50 g Diethylene glycol and 1 g of finely pulverized catalyst depending on the embodiment shown in Table I below, (In Example 9, only 25 g of diethylene glycol and in Examples 7, 3, 10, 11 and 14, 100 g of diethylene glycol were used). The reactor was now capped, purged twice with molecular hydrogen at 500 psig (35 at) and charged to an initial charge of molecular hydrogen after a pressure test. The initial pressure of the molecular hydrogen is for each embodiment

C Η * 4 O Ό Ζ » / -26- 09.06.1933

AP C 07 0/244 392 (61 497/12)

in Table I. The magnetic guide was started and set at 100 rpm; the reaction sintering was then heated to the temperature indicated in Table I for each embodiment! After a six hour reaction period, the reactor was cooled, the stirring was discontinued, and the pressure was slowly released. (The reaction time was only 4 hours in export sections 1, 2 and 3). _E "During the degassing step a product gas sample was taken for gas chromatographic analysis. * The remaining liquid content of the reactor was then removed, weighed and analyzed by gas chromatography * Performance of the tested in the embodiments 1 to 18 catalysts is shown in Table I.

table

-Hydrogenolyae (ühargenyerfahren) - Product data

Tlus f ud h ot ~ ~ ~

Catalya labeling temperature, 0 C initial pressure; (EL) »psig

at

Reactlonarates (mol / kg cat / hr) in terms of mono e t hy 1 engl y Ic ο 1 ethanol et han

Mono et; hy 1 emgly kol-monometallic hylether Mono e thy1engly kol-Ivlono et hy 1 üioxan et he r methanol

2-Oxodloxane />

1,2-butanediol> f5 <Other substances ¹ "'Selelctivität (IViol.pxOzent) Mono at hy englykol Monotne t hy 1 et r e monoethylene glycol ethanol

III 250 250 250 250 500 1000 17.5 35 70

II

-250

1000

70

4.4 4.2 5.6 2.9 7.3 9.2 0.49 0.28 0.39

6.6 3.2 13.4 7.2 0.16 0.30

19.3 21.5 30.4 15.7 25.0

0.14

1.6

WD

WD

0.2 _s 7

1.84

0.17 1.7

ND WJ) ND 0.61

76

17

11

76 15 25 0.36

3.4

ND

M)

0.01

1.22

0.48

3.2

0.03

IiD

0.01

0.11

58 25 50

0.19

2.4

0.15

ND

ND

1.41

76 10 22

IV 250 1000 70

3.8 3.0 0.42

23.9

0.22

2.2

0.45

0.07

HD

1.36

79 13 10

III

250

100

  7

1.38 1.42 0.61

4,04

0.032

0.239

0.067

0.081

HD

0,251

22 22

In this amount T, small amounts of 4-butyrolactone and diethylene glycol monoethyl ether may also be contained.

(b) Includes n-butanol, acetaldehyde, diethyl ether, dimethyl ether, 2-methyldioxoles, 2,3-butanediol, propylene glycol, triethylene glycol, and unknowns.

(Fort sat ζ ung) j

eaglycol-hydrofi-e no Iyae (Cihaygenyer) ~ Product data

7l "us f li hr mm a b ~ el a pTe 1

aTy sa ^ torkennze iohnurig temperature $ ⁰ G initial pressure (H ₀ ) pülg

^ά at

Reaction rate (mol / kg iiat _e / h) is considered to be monoethylene glycol ethanol ethane

Mono e t hy 1 ongly col ~ Mono me t hy lethe r Monoethylene glycol monoethyl ether Methanol Dioxane 2-0xodioxane / \

(B)

"1,2-butanediol

Other substances

ijelekt ivi tat (mole percent)

Monoet ethylene glycol

Monomet hy1et he r

Monomethylene glycol

ethanol

ΓΪΓ

250! 300

250

1000. 70

1.07 1.01

1.33 0.460

0 _? 050 0,243

5.16 19.6

0.025 0.156

0.329 0.510

Nl) 0.049

ND ND

OJ59-0207

79 16

20

94 5 2

10

250

1000

70

- "ΤΪΓ

250

2000

140

1.33

0.865 0.132

4.09 5.35 0.257

9.17 36.1

0.088 0.887

MD HD WD 0,112

87 13

0,330

5.24

0.91

ND

0.172

0.657

10 13

HI

225

1000

70

1.56 1.42 0.050

10.0

0,060

0.731

ID ND ND 0,208

13 13

TLT "

200

100

2.24 0.697 1.80 0.310 0.103 ND

8.84 0.727

0.071 1.02 0.081 ND ND

ND ID

ND HD

0.312 0.071

20 16

TaTTn, know this amount aucK'kTeine amounts of 4-butyrolactone and

Be contained diethylene glycol monoethyl ether. (b) Includes n-butanol, acetaldehyde, diethyl ether, dimethylethene, 2-methyldioxoles,

Butanediol, propylene glycol, triethylene glycol and unknown substances »56 54 24

2,3

IY)

Ω O

(V)

Tabel le I (continued) j

Polyalkylene glycol - Hydrpg; enolyaa (batch process) - Product data

A ~ u £ ifi .i hrjingabeiap'Tel TTa ta Iy sat or lc temperature, ⁰ O initial pressure (H ₉ ), psig

^d at

Reactionary te (mol / kg cat / hr) with respect to: Mono et hy 1 eigig l Etanol ethane

Monoethylene glycol Monome ~ t t he r hy1e monoethylene glycol monoethyl ether Me t HANOL dioxane 2-0xodioxan / _Λ s

, 5

Other substances ^{v J}

Selectivity (molproprode)

ivionoethylenglylcol-

Ivion onie t hy 1 e t h e r

Mono et hyalcohol

ethanol

250

2000

140

250

1000

70

~ TT 250 1000 70

0.50 0.82 2.33 0.056

47 32 28

4.21 2.93 0.75

8.87

0.65 1.16 3.60 0.18

WD 0.05

51

24 17

4.5 4.8 0.10

17.6

0.11 1.8 IMD 0.01 ND 0.72

78 20 21

and

Χο) '~ Ύϊϊ "d'ieiem amount Eönneh even small amounts of 4 ™ Butylrolakton, diethylene glycol Monoöthylether contains en Ain.

(b) comprises n-butanol, acetaldehyde, diethyl ether, dimethyl ether, 2-methyldioxolane, 2-butanediol, propylene glycol, triethylene glycol and unknowns

"TTT 250 1000 70

3.9 4.0 0.47

13.5

0.47 1.4 0.89 0.21 ND 0.17

69 20 21

Ω VO O

VD [\ J

4 4 O Ό έ 1 -30- 09.06.1933

AP C 07 0/244 392 (61 497/12)

Embodiments 1 through 18 illustrate the overall effectiveness of nickel-containing compositions as hydrogenation catalysts in the present invention. A composition containing at least about 10% by weight is the preferred hydrogenation catalyst for use in the hydrogenolysis process of the present invention used as a hydrogenation catalyst, then the selectivity of monoethylene glycol monomethyl ether can reach 95 mole percent (see Example 9) ₅ wherein additionally in gegeringeren amounts of monoethylene glycol and ethanol are produced «Embodiment 11 shows that the rate of formation of Monoethylenglykol-Monoüiethylether from diethylene glycol 36 mol kg / h and that the combined rate of formation of monoethylene glycol and ethanol from diethylene glycol was greater than 9 mol / kg Xato / h *, (See also Example 3 with an R ate the formation of monoethylene glycol monomethyl ether from diethylene glycol of more than -3 * 0 mol / kg cat / h and a combined rate of formation of monoethylene glycol and ethanol from diethylene glycol of over I4 mol / kg £ at -, / h ·) the rates are high enough to be considered as industrially desirable "Hickel has the further? orteil ₅ that it is available and relatively inexpensive a number of suppliers in a variety '' of formulations ,,

Embodiments 7 to 11 illustrate the effect of pressure on the hydrogenolysis reaction using the same hydrogenation catalyst, d, h. of the catalyst III, as well as the same temperature, d. tu 250 ^Q C as can be seen from the embodiments 9- W & -10 is a pressure of eivra. 1000 psig (70 at) for the achievement of overall satisfactory and desirable performances. to prefer"

£ 4 4 J ά 2 7 -31- 09.06.1933

AP C 07 G / 244 392 (61 497/12)

The most preferred pressure for the production of monoethylene glycol monomethyl ether, monoethylene glycol and ethanol ranges from about 500 psig to about 2000 psig (35 to 140 at).

Embodiments 7 to 14 illustrate the effect of temperature on the hydrogenolysis reaction using the same hydrogenation catalyst _. ie «the catalyst III. As can be seen from the Ausfuhroagsbeispielen 9 and 10, a temperature of about 250 ⁰ C to achieve an overall desirable performance preferred The most preferred temperature for production of monoethylene glycol monoethyl ether, monoethylene glycol and ethanol is in the range of about 175 to 250 ⁰ G.

The Example 1 to 6 illustrate the effectiveness of other hydrogenation catalysts (commercially available) with different Liickelkonzent rat ions (catalysts I ₃ II and IY) in the hydrogenolysis Veriahren invention,

The embodiments 15 to 18 illustrate the use of hydrogenation catalysts such as catalysts Y to YlI containing 10% by mass of iJickel. It is apparent from the working examples that when using a hydrogenation catalyst with the preferred 10% by mass at least one of the compounds monoethylene glycol monomethyl ether monoethylene glycol and Ethanol is produced * E3 is noted that monoethylene glycol monomethyl ether is produced in predominant amounts when the catalysts V to VII (see Ausführungsbeispieie 15 to 13) are used as hydrogenation catalysts in the process according to the invention *

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Execution 19 to 21

The Aasführungsbeispiele 19 bia 21 were mixed in a 3/4 χ under running conditions 16 inches (19 χ 406 mrn) outer diameter tube reactor rostfreiem'Stahl (35 ml volume) ,,, with a 1.5 mm diameter '· T e nip In the case of a stainless steel coaxial attachment, it was carried out in accordance with the following procedure: A 5-g catalyst was used as described for each embodiment in Table II below Volume of glass coils dispersed and introduced into the stainless steel tube reactor, with one Sett of glass turn took in the space above and below the inserted catalyst. The catalyst was then reduced by heating at 150 ⁰ C under flowing nitrogen in the tube reactor made of stainless steel "then molecular hydrogen was introduced and auf.eine concentration of about 10 volume percent set" The temperature as well as the concentration of molecular 'is hydrogen were then stepwise Increased over a 43-hour period until the temperature reached 250 G and the reducing atmosphere reached a concentration of 100 percent by volume of molecular hydrogen. "• The pressure was increased from ambient to 1000 psig (70 at); this was done over a 30-minute period before swirling to the desired operating temperature, after which the temperature and rate of molecular hydrogen plating were reduced to their desired levels. Grade · set in a container filled with glass helices preheater same dimension as the tube reactor made of stainless steel were diethylene glycol and molecular hydrogen premixed at 275 ⁰ G, Die.Reaktionsteilnehmer were then passed downwardly through the catalyst bed, wherein the in

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AP G 07 C / 244 392 (61 497/12)

Table II for temperature, pressure, gas and liquid flow rates (GHSV and LHSY). The products were condensed and collected under reactor pressure. The liquid products as well as the uncondensed gases were sampled at intervals and analyzed gas chromatograph is cn. Tightly converted molecular hydrogen was not used again. The performance of the catalysts tested in Examples 19 to 21 is shown in Table II.

09 * 06.1983.

AP G 07 G / 244 392

(61 497/12)

Table IJ .: Polyalkylene glycol hydrogenolysis (continuous process ) P roduct data

Out of us; SExample 19 20 21 iiatalysatorkermzeichnung III III III Temperature ⁰ O 200 185 215 Pressure (H ₉ ) j paig (at) GHSV (H ₂ 7, h-1 1000 (70) 500 (35 1200 LHSY (DSG), h- ¹ 33500 1 3500 38500 Reaction rate (mol / kg * cat, / h) 2.8 0.9 2.9 regarding: · Mono e t hy Ienglyk oil Bthanol 1.14 0,336 0.838 Et han 0.365 0.231 0,762 Mono et hyalcoholic JJD ND HD monomethyl Monomethylenglykol- " 3.42 0.752 5.12 monoethyl methanol 0,051 0.011 0,055 Dio2: at 0.463 0.097 0,864 2-03: odio5: an / \ 0.047 0.028 0,022 1,2-3utandiol>: ( m 0,007 0,045 Other stuff e ^KJ in the HL  ΈΊ) Selectivity (mole percent) 0, 030 0,030 m monoethylene Monomethy1ether Monoethylene glycol 75, 68 35 ethanol 25 30 1 d. 19 21 13

(a) In this. Amount may also contain small amounts of 4-butyrolactone and diethylene glycol monoethyl ether,

(b) Includes n-butanol, acetaldehyde, diethyl ether, dimethyl ether, j-2-methyldiosolane, 2,3-butanediol, propylene glycol, triethylene glycol, and unknown substances. «

L 4 H ό Ό £ / -35- 09.06.1983

AP C 07 C / 244 392 (61 497/12)

Embodiments 19-21 illustrate the overall effectiveness of the present invention when used in a continuous process. "A composition containing at least about 65% by weight iJikkel is the most preferred hydrogenation catalyst for use in the inventive flow-through process. The use of a composition containing 65 percent by weight of Nikkei as the hydrogenation catalyst in the continuous process yielded selectivity of monoethylenediol monomethyl ether in Example 21 of 85 mole percent. "The rate of formation of monoethylene glycol uionomethyl ether resulting from the continuous process is also high enough to be considered industrially desirable (See particularly Embodiment 21) β Embodiments 19 to 21 illustrate a desirable temperature range, pressure range, GHSV range, and HSV range as used in the continuous process, temperatures ranging from about 175 G to about 2650 and pressures in the range of about 1000 psig to about 2000 psig (70 to 140 at) are considered to be most preferred for obtaining high monoethylene glycol monomethyl ether selectivities as well as rates in addition to the production of monoethylene glycol and ethanol in small The hourly gas space velocity (GHSV) as well as the hourly liquid space velocity (LHSV) can be varied within a wide range using the continuous flow method. Hourly gas space velocities of about 2000 h to about 75000 h ~ and hourly P-Lüssigkeits-

-1 -1 '

Space velocities of about 0.25 η to about 10 hours are considered most preferable for obtaining desirable selectivity and rates. "

Claims (7)

(61 497/12) invention claim A process for the selective cleavage of a polyalkylene glycol containing at least one ether group on a covalent carbon-to-oxygen bond so independently on a covalent i-carbon-z-carbon bond. characterized in that such a polyalkylene glycol is heated with molecular hydrogen in the presence of a nickel-containing hydrogenation catalyst so as to produce in this way at least one of the compounds monoethylene glycol monomethyl ether, monoethylene glycol and ethanol. 2. The method according to item 1, - characterized in that produced in predominant quantities Monoethylenglykol Monomethyiether, .. 3. Method according to item 1, characterized in that the hydrogenation catalyst is a composition containing at least about 10% by mass of hemp. 4. The method according to item 1, characterized in that it is the composition containing at least about 65% by weight of nickel in the hydrogenation catalyst » 5. The method according to item 1, characterized in that it   the polyalkylene glycol is diethylene glycol. ^ / / O Π O * "7 ./ 4 4 JZJ £ / -37- 09.06.1983 AP G 07 C / 244 3-92 (61 497/12) 6 «method according to item-1, characterized in that the polyalkylene glycol and the molecular hydrogen in a, molar ratio of molecular hydrogen to polyalkylene glycol of about 1:20 to. to about 2000: 1 are present. 7. The method according to item 1, characterized in that the hydrogenation catalyst in an amount of about 0.01 percent by mass bia to about 50 percent by mass - based on the total mass of Reaktionsgeaiisch - is present * S. The process of item 1, characterized in that the polyalkylene glycol has an hourly liquid space velocity of from about 0.01 hour to about 100 hours and that the molecular hydrogen has an hourly gas hemeration speed of about 100 hours about 100 000 h ^-1 . 9. The method according to item 1, characterized in that the temperature is about 125 ⁰ G to about 350 ⁰ G. 10. The method according to item I _3, characterized in that the molecular pressure originating from the molecular hydrogen is between about 100 psig and etv7a 4000 psig (7 to 230 at) *