Abstract: The present invention relates to a process for hydrolytically depolymerizing a polyamide prepared from ?-caprolactam and an apparatus for carrying out a process for hydrolytically depolymerizing a polyamide prepared from ?-caprolactam.

Abstract: A process for regenerating hydrogenation catalysts based on a platinum metal, where the hydrogenation catalysts based on a platinum metal are thermally regenerated at temperatures of from 50 to 600° C.

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.