Abstract: Acetylene is removed from a crude C.sub.2 -stream by scrubbing with an absorbent in an absorption column, a liquid, substantially acetylene-free C.sub.2 -stream being fed into the absorption column between the feed points for the crude C.sub.2 -stream and for the absorbent.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: n-Alkenes can be converted catalytically into isoalkenes, when a mixture containing at least one n-alkene and hydrogen is brought into contact at a temperature of 400.degree. to 600.degree. C. and a residence time of 0.2 to 20 seconds with an Al.sub.2 O.sub.3 or SiO.sub.2 catalyst which is specifically activated and is promoted with halogen compounds of elements of the third to fifth main groups and second to eighth sub-groups of the periodic system and/or hydrohalic acids. The specific activation comprises calcining, before the promotion process, an aluminum hydroxide or aluminum oxide hydrate or a silica gel having a content of volatile ammonium salts to give Al.sub.2 O.sub.3 or SiO.sub.2, with expulsion of these volatile ammonium salts. For the conversion of the n-alkenes, the catalyst can be employed in a fixed or a mobilized catalyst bed.

Abstract: Silver-containing supported catalyst, catalyst intermediates, processes for their preparation and the use of such catalysts in the preparation of alkaline oxides is described. By the preparatory technique of the invention there is obtained an improved catalyst which is especially useful in the preparation of alkylene oxides by oxidation of alkenes with oxygen-containing gases. The novel catalysts are characterized by a BET specific surface area of about 0.4 to about 0.5 square meters per gram and by a uniform continuous particle structure of spherical silver crystallites on a supported catalyst, which crystallites have an average diameter of 0.3 to 0.4 .mu.m.

Abstract: 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.

Abstract: 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.

Abstract: A process and apparatus for the separation of components from a mixture which forms an azeotrope is disclosed by subjecting the mixture to extractive distillation to remove one of the components and regeneration to separate another component from the extracting agent added to the extractive distillation column. According to the invention, a first side stream is withdrawn from the extractive distillation column, passed in heat exchange with the bottoms from the extractive distillation column en route to the regeneration column and returned to the extractive distillation column at a point below the point at which it is withdrawn. A second side stream from the extractive distillation column is withdrawn, passed in heat exchange with the bottoms of the regeneration zone and returned to the extractive distillation column. For this purpose, separate heat exchangers are used for the respective side streams.

Abstract: 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:(a) Employing as the cation exchanger a macroporous or gelatinous acid cation exchanger in the H.sup.+ form which has been charged with 0.1 to 5 grams, per one liter of dry cation exchanger, of an elementary form of a metal of sub-groups VI, VII or VIII of the periodic table of elements (Mendeleev) which cation exchanger is crosslinked with the degree of crosslinking of 2 to 65% and has a specific surface area of 5 to 750 square meters per gram on the basis of dry cation exchange resin; and(b) The reaction is carried out in the liquid phase at a temperature of 30.degree. to 140.degree. C. at a pressure of 2 to 100 bars employing a molar ratio of isoolefin to alkanol of 0.1 to 5.

Abstract: An improved process for the absorption of an olefin in a silver salt solution and the recovery thereof by desorption is disclosed wherein the silver salt of the silver salt solution is silver trifluoroacetate.

Abstract: An improved process for the preparation of triethylamine by gas phase catalytic hydrogenation of acetonitrile is disclosed, the improvement residing in employing as the catalyst a supported noble metal of Group VIII of the periodic system catalyst where the support comprises lithium aluminum spinel. The process can be carried out in the presence of up to 5% by weight of monoethylamine and/or diethylamine. The process is conducted at 80.degree.-115.degree. C. and under a pressure of 1 to 60 bars.