Abstract: Polyisobutene is prepared by cationic polymerization of isobutene and/or isobutene-containing hydrocarbons in the liquid phase in the presence of a complex of BF3 and at least one cocatalyst which is preferably chosen from oxygen-containing compounds, the BF3/cocatalyst complex being produced in situ by adding BF3 and cocatalyst to a reaction stream, wherein BF3 and oxygen-containing cocatalyst are added to the reaction stream via a common binary nozzle comprising an outlet for BF3 and an outlet for the oxygen-containing cocatalyst. The invention also describes a binary nozzle having a centrally arranged outlet for the catalyst.

Abstract: Polyisobutenes are prepared by the continuous preparation process, by polymerizing isobutene in the presence of a catalyst comprising boron trifluoride and at least one cocatalyst in an inert organic solvent, a) a part of the reaction mixture obtained thereby being discharged continuously from the polymerization reactor, b) the catalyst being separated from the discharge and/or being deactivated in the discharge, and c) the solvent and any unconverted isobutene being separated from the discharge and recycled to the polymerization reactor, wherein the recycled solvent and, if present, the isobutene are subjected to a wash with water before recycling to the polymerization reactor and are then dried.

Abstract: Acetaldehyde is removed from C.sub.3 -C.sub.15 hydrocarbons by contacting the hydrocarbon or a hydrocarbon mixture in liquid phase with a zeolite whose pores have a width which is greater than 0.3 nm and up to 0.75 nm.

Abstract: Isobutylene polymers are prepared by polymerizing the monomers at from 0.2 to 20 bar and from -130.degree. and +60.degree. C. in the presence of from 0.01 to 20 mmol of a boron halide catalyst system which contains as cocatalyst a carboxylic anhydride or carbonyl halide, preferably an aliphatic or aromatic, unsubstituted or halogen-substituted C.sub.4 -C.sub.18 -carboxylic anhydride of C.sub.2 -C.sub.12 -carbonyl halide and where appropriate also a customary polymerization accelerant in customary amounts, in the presence or absence of an inert solvent with dissipation of the heat of reaction.

Abstract: A C.sub.4 -hydrocarbon mixture which essentially contains n-butenes and butanes is separated by a process in whichthe mixture is reacted with a carboxylic acid in the presence of an acidic catalyst to form a butyl carboxylate,the reaction mixture obtained from the esterification zone is distilled to give, as the top product, a fraction containing the butanes, and, as the bottom product, a fraction containing the resulting butyl carboxylate,the butyl carboxylate is decomposed at elevated temperatures to give the carboxylic acid and n-butenes, andthe mixture of n-butenes and carboxylic acid is then distilled, the n-butenes being obtained as the top product, and the carboxylic acid as the bottom product.

Abstract: A process for conjointly preparing methyl tert.-butyl ether and obtaining isobutene from an isobutene-containing C.sub.4 -hydrocarbon mixture. In the process the C.sub.4 -hydrocarbon mixture is reacted, in one or more etherification stages, with methanol and a primary C.sub.3 - or C.sub.4 -alcohol in the presence of an acid condensing agent, the resulting reaction mixture or mixtures are then separated into a fraction containing the unconverted hydrocarbons, the methyl tert.-butyl ether and a fraction containing the C.sub.3 - or C.sub.4 -alkyl tert.-butyl ether. Thereafter, the C.sub.3 - or C.sub.4 -alkyl tert.-butyl ether is decomposed at an elevated temperature, in the presence of an acid catalyst, into isobutene and primary C.sub.3 - or C.sub.4 -alcohol.

Abstract: A process for obtaining isobutene from a C.sub.4 -hydrocarbon mixture containing isobutene, by reacting the mixture with a primary alcohol in the presence of an acid condensing agent and decomposing the resulting tertiary ether in the presence of an acid catalyst at an elevated temperature, wherein a primary C.sub.3 - or C.sub.4 -alcohol is used.

Abstract: p-alkylphenols are manufactured by continuous reaction of phenol with olefins in the presence of a pulverulent polystyrenesulfonic acid ion exchanger which is suspended in the reaction mixture.