Ec Erdolchemie Gmbh

Bayer Aktiengesellschaft

Ec Erdoelchemie Gmbh

Bernhard Schleppinghoff

Hans-Volker Scheef

Christian Gabel

Hans-Dieter Kohler

Horst Reinhardt

Peter M Lange

Jens Herwig

Bruno Schulwitz

Mathias Lux

Alfred Mitschker

Hans-Joachim Kramer

Herbert Tschorn

Reiner Malessa

Klaus Munter

Martin Becker

Hans-Ludwig Niederberger

Herbert Tachorn

Klaus Mainusch

Alkyl tert.-alkyl ethers can be cleaved into the underlying alkanols and tert.-olefins in the presence of strongly acidic substances in a column apparatus, the strongly acidic substance being made available at the foot of the column. A particularly advantageous process design results when a water stream is fed below the top column tray in countercurrent to the tert.-olefin flowing upwards and is taken off again from the column above the bottom circulation; in the case of using an insoluble, strongly acidic substance, the latter is located in a catalyst bed at the foot of the column, and the alkyl tert.-alkyl ether is preferably fed in between the catalyst bed and the bottom circulation evaporator.

Process for cleaving alkyl tert.-alkyl ethers

Gum-free fuel components containing alkyl tert.-alkyl ethers have been found which can be prepared by reacting a crude hydrocarbon mixture containing gum-forming constituents and containing one or more tert.-olefins, simultaneously with alkanols and H.sub.2 on a certain exchanger in the H.sup.+ form containing one or more metals of sub-group VI, VII or VIII of the periodic table of the element in element form, in the liquid phase at 30.degree. to 140.degree. C.

Gum-free components containing alkyl tert.-alkyl ethers

Tert.-olefins are obtained in high purity by cleavage of their alkyl ethers, when the catalysts used for this purpose are styrene/divinylbenzene resins which contain sulphonic acid groups and have a macroporous structure and the polymer matrix of which has an internal surface area of at least 400 m.sup.2 /g, a pore volume (porosity) of 0.6-2.5 ml/g and a mean pore diameter of 40-1000 .ANG.. These catalysts show long service lives.

Process for the preparation of tert.-olefins

Alkenes having a terminal double bond can be isomerized to give alkenes having an internal double bond if alkenes having a terminal double bond or hydrocarbon feedstock having a content of alkenes of this type having a terminal double bond are subjected to treatment, in the presence of hydrogen, over a macroporous or gel-like cation exchanger in the H.sup.+ form which contains 0.001 to 10 g of one or more metals of the VIth and/or VIIth and/or VIIIth sub-group of the periodic system of the elements in elementary form per liter of dry cation exchanger and which has a degree of crosslinking of 2 to 65% and a specific surface area of 5 to 750 m.sup.2 /g of dry exchange resin. The treatment is carried out in the liquid phase at a temperature from 0.degree. to 120.degree. C.

Process for the isomerization of alkenes having a terminal double bond

Tert.-Amyl alcohol (TAA) can be prepared in an advantageous manner by hydrating of i-amylenes on an acid cation exchanger by carrying out the reaction in the vicinity of the boiling point of the i-amylenes under the appropriate reaction pressure. A higher content of TAA is thereby obtained in the reaction mixture.

Process for the preparation of tert.-amyl alcohol (TAA)

Olefinic hydrocarbons present in mixtures containing tert.-alkyl alkyl ethers and, if appropriate, other saturated aliphatic or aromatic hydrocarbons can be hydrogenated with substantial preservation of the ethers if the catalyst used has an active component for hydrogenation on a catalyst support having a specific surface area of more than 50 m.sup.2 /g and a pore diameter of, in the main, &lt;1,000 nm.

Process for the hydrogenation of olefinic hydrocarbons in hydrocarbon

Crosslinked organic resins, containing SiO.sub.2 and sulphonic acid groups, having an SiO.sub.2 content of 0.1-10% by weight, relative to the total weight of the SiO.sub.2 -containing resins, are prepared by steeping crosslinked organic resins, containing sulphonic acid groups, in the alkali form in aqueous alkali metal silicate solutions or (quaternary) alkylammonium silicate solutions, and subsequently precipitating the SiO.sub.2 using mineral acid, and simultaneously converting the resin into the H.sup.+ form. These resins can be used as acid catalysts in the cleavage of tert.-alkyl ethers into the basic tertiary olefins and the basic alkanols. This use has proven particularly advantageous when the tert.-alkyl alkyl ethers to be cleaved are employed together with water for the cleavage.

Crosslinked organic resins containing SiO.sub.2 and sulphonic acid groups

Tertiary olefins are obtained in pure form by cleavage of the pertinent tert.alkyl ethers with simultaneous formation of the pertinent alcohols on strongly acidic cation exchangers in the H.sup.+ form. This cleavage is carried out at elevated temperature and atmospheric to superatmospheric pressure. The process is carried out in such a fashion that the ether to be cleaved is employed as a mixture with water. The water may be employed in an amount from 2-50% by weight, relative to the amount of the ether to be cleaved. Suitable ethers to be cleaved are those based on tertiary C.sub.4 -C.sub.7 -olefins and primary C.sub.1 -C.sub.4 -alkanols.

Process for the preparation of tertiary olefins

A process for the preparation of pure alkyl tertiary alkyl ethers and hydrocarbon raffinates which are substantially free from tertiary olefins and alkanols. An alkanol and a hydrocarbon mixture containing at least one tertiary olefin are contacted with the alkanol being present in a stoichiometric excess. The reaction product is removed from the reaction zone and excess alkanol in the reaction product or a partial stream thereof is absorbed on a synthetic ion exchanger containing groups which exchange cations or anions or mixtures of such ion exchangers. After absorption of at least a portion of the alkanol on the synthetic ion exchanger, the alkanol is desorbed by contacting the same with a hydrocarbon mixture containing at least one tertiary olefin.

Process for the preparation of pure alkyl tert-alkyl ethers and

In the reaction of methanol and of i-butene which is contained in a hydrocarbon mixture on an acid cation exchange material to give methyl tert.-butyl ether (MTBE), methanol and i-butene can be used in essentially equimolar amounts if simultaneously to the distillative separation of the etherification mixture into its constituents this etherification mixture is passed into a secondary reaction. To do this, the etherification mixture is fed into a distillation column and from above the feed-in point a liquid distillate stream is taken off and passed in a secondary reactor over an acid cation exchange material. The mixture leaving the secondary reactor is returned below its take-off point.

Process for the production of methyl tert.-butyl ether (MTBE) and of

Unsaturated hydrocarbons and mixtures in which the latter are present are treated with anion exchangers prior to hydrogenation and are then hydrogenated catalytically in a known manner. The treatment with anion exchangers is carried out at 0.degree.-120.degree. C. and at a space velocity of 0.1 to 10 l of hydrocarbons to be hydrogenated per l of exchanger, per hour. The process avoids other, energy-intensive pretreatments, for example distillation of the hydrocarbons to be hydrogenated, or washing, and can be carried out in simple equipment. A considerable prolongation of the catalyst operating time is achieved in the subsequent catalytic hydrogenation.

Process for the hydrogenation of hydrocarbons

Pure tert.-olefins are prepared from mixtures of hydrocarbons, which contain at least one such tert.-olefin, by reaction with an alkanol to give the corresponding alkyl tert.-alkyl ethers, and subsequent cleavage of these ethers back to the corresponding pure tert.-olefins and the alkanol, and the separation of the pure tert.-olefin from the alkanol. For this, the alkanol present after the cleavage of the ether is separated from the tert.-olefin to the extent of 60 to 99% by weight by distillation, and the residual amount of alcohol in the olefin fraction is removed by adsorption from this fraction onto a synthetic ion exchanger as an absorber resin. The admixture of the alkanol to the mixture of hydrocarbons with at least one tert.-olefin is carried out partly by using the alkanol fraction arising from the separating off of the pure tert.-olefin, and partly by desorption of the alkanol from the absorber resin with the aid of the mixture of hydrocarbons containing at least 1 tert.-olefin.

Process for the preparation of pure tert.-olefins

A fuel for a carburetor type engine consisting essentially of isobutene oligomers and methyl tert.-butyl ether, said fuel prepared by a process comprising: (a) in a first step contacting a mixture of straight chain and branched butanes and butenes with an acid catalyst whereby to oligomerize 50% to 90% by weight of the isobutene contained therein: (b) contacting the reaction mixture from step (a) with at least a molar amount of methanol, relative to the residual isobutene, in the presence of an acid catalyst; and (c) separating off from the reaction mixture unreacted butanes and butenes.

Process for the preparation of a mixture consisting essentially of

Process for the preparation of tertiary olefins by catalytic cleavage of their n-alkyl ethers at elevated temperature and with simultaneously recovery of the corresponding n-alkanols, characterized in that the cleavage is carried out in the presence of acidic molecular sieves, which have been activated, if necessary, by a treatment with hydrogen, at temperatures of from 100.degree. to 300.degree. C.

Process for the preparation of tertiary olefins and n-alkanols

In a process for the preparation of an alkyl tert.-alkyl ether by reaction of an isoolefin branched at the double bond and an alkanol in the presence of a cation exchanger, the improvement which comprises:

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Dormagen, Germany

Bernhard Schleppinghoff