Basf Aktiengesellschaft

Ernst Lang

Ulrich Hammon

Volker Schliephake

Klaus Joachim Müller-Engel

Jürgen Schröder

Reinhold Kohlhaupt

Klaus-Dieter Malsch

Walter Bieg

Douglas Hutton

Carl-Ludwig Krüger

Organic compounds are prepared by heterogeneously catalyzed partial gas-phase oxidation of precursor compounds by a process in which a portion of the reaction gas starting mixture is brought from a low initial pressure to a higher final pressure by means of a radial compressor.

Preparation of at least one organic compound by heterogeneously catalyzed partial gas-phase oxidation

In a process for the recovery of N-ethylpiperazine by distillation from mixtures with N,N'-diethylpiperazine, piperazine, ethanol, water and accompanying substances, water is added in a manner such that, at the location of the addition of the water, the piperazine concentration is greater than the N-ethylpiperazine concentration. The water may be added to the reflux to the top of the column.

Recovery of N-ethylpiperazine by distillation

A process for purifying indigo comprises stripping the as-synthesized aqueous alkaline indoxylate solution before its oxidation to indigo of impurities in the absence of oxygen by distillation or by passing in steam or an inert gas and then treating the indigo precipitated on oxidation of the stripped indoxylate solution with dilute hydrogen peroxide solution.

Purification of indigo

Growing community of inventors

Wachenheim, Germany

Ernst Lang