Abstract: Structured multi-purpose packings and their use in a physical material separation process, the packings containing material separation elements (1) and second functionality elements (2) provided in alternate layers, wherein the material separation elements have a profiled surface, and each of the second functionality elements has two or more closed chambers (3) provided on top of each other and filled with a physically, chemically or biologically active packing material, a space being provided between any two of the chambers, which space is bridged by a section (6) conducting a liquid, characterized in that the walls of the chambers of the second functionality elements are constituted by a polymeric material.

Abstract: The invention relates to a process for preparing diisobutylene (DIB) from an i-butene-containing C4 raffinate I, in which the C4 stream is passed through a first hydroisomerization reactor (A) and a fractionation column (B) and is thus largely freed of 1-butene and 2-butene. It is subsequently dimerized over an acidic catalyst installed in a reactive column (E). The feed stream to this reactive column contains not only i-butene but also butanes which make the reaction temperature in the fixed bed controllable by removal of the heat of reaction. In the fractionation column (B), a side stream can be subjected to a further hydroisomerization in a reactor (C).

Abstract: A process is provided which makes it possible to separate off cyclic acetals from wastewater streams to a substantial extent, by passing the wastewater stream over a heterogeneous acid catalyst.

Abstract: Tertiary alcohols can be prepared by the hydration of tertiary olefins having the same number of carbon atoms on an acidic ion exchanger using special structured multi-purpose packings for heterogeneous reactive rectification. An excellent yield and purity of the alcohol and an extended service life of the catalyst are achieved.

Abstract: Process for isolating one or more organic substances from a gas mixture in which these organic substances are present, in which the gas mixture is subjected to a quenching in a column, characterized in that quenching is carried out in the upper part of the column and the quenching liquid is subjected to stripping in the lower part of the column.

Abstract: Cyclopentane and/or cyclopentene and, if desired, isopentane can be obtained by distillative separation from a pre-benzene fraction or a C5 fraction which has in each case being partially hydrogenated to remove acetylene compounds and diolefins, wherein a) in a first fractional distillation, low boilers are removed as first top product and, either b1) the first bottom product is fed to a second fractional distillation and there cyclopentene is taken off as second top product and cyclopentane and higher-boiling hydrocarbons are taken off as second bottom product and this second bottom product is separated into cyclopentene and higher boilers in a third fractional distillation, or b2) the first bottom product is subjected to a catalytic hydrogenation and subsequently, in a fractional distillation, separated into cyclopentane as top product and higher boilers as bottom product, or b3) the first bottom product is subjected to a fractional distillation to separate off the relatively high boilers as bottom prod