Ec Erdolchemie Gmbh

Bayer Aktiengesellschaft

Hans-Volker Scheef

Bernhard Schleppinghoff

Jens Herwig

Christian Gabel

Hans-Dieter Kohler

Peter M Lange

Bruno Schulwitz

Arnd Stuwe

Herbert Tschorn

Jorg-Uwe Michel

Mathias Lux

Reiner Malessa

Herbert Tachorn

High-octane, low-olefin motor fuels and motor fuel components having a content of alkyl tert.-alkyl ethers can be produced by reacting a crude hydrocarbon stream, which contains tertiary C.sub.5 -C.sub.8 -olefins in addition to saturated and olefinically, diolefinically and acetylenically unsaturated hydrocarbons in the same boiling range, simultaneously with one or more C.sub.1 -C.sub.4 -alkanols in a quantity from 0.5 to 5 mol per mol of the tertiary olefin(s) and with excess hydrogen relative to the total unsaturation under a pressure from 12 to 80 bar and at a temperature from 60.degree. to 180.degree. C. on a catalyst known per se or a mixture of catalysts known per se, which effect(s) both the etherification and the olefin hydrogenation.

Process for producing high-octane, low-olefin motor fuels and motor fuel

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

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)

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

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

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.

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Dormagen, Germany

Hans-Volker Scheef