Evonik Operations Gmbh

Evonik Degussa Gmbh

Evonik Oxeno Gmbh & Co. Kg

Lena Altmann

Robert Franke

Michael Grass

Horst-Werner Zanthoff

Johannes Kraft

Johan Anton

Dirk Fridag

Katrin Marie Dyballa

Guido Stochniol

Dietrich Maschmeyer

Stephan Peitz

Frank Geilen

Monika Berweiler

Helene Reeker

Meike Roos

Corinna Hecht

Markus Göttlinger

Jörg Schallenberg

René Poss

Benedikt Dercks

Stefan Wieland

Thomas Schneider

Hanna Spohr

A process prepares dialkyl 1,4-cyclohexanedicarboxylates by ring hydrogenation of the corresponding dialkyl terephthalate having a CO value of less than 0.3 mg KOH/g. The dialkyl 1,4-cyclohexanedicarboxylates thus produced can be used as plasticizers or as a component of a plasticizer composition for plastics, in particular PVC.

Process for preparing dialkyl 1,4-cyclohexanedicarboxylates

The invention provides a process for regenerating a catalyst used for the ring hydrogenation of an aromatic species, especially an aromatic ester, wherein a gas stream containing a particular amount of oxygen is used for the regeneration.

Process for regeneration of hydrogenation catalysts

The present invention relates to a process for preparing C-Calcohols by catalytically hydrogenating the corresponding aldehydes at a temperature in the range of 50-250&#xb0; C. and a pressure in the range of 5-150 bar in the presence of a supported activated Raney-type catalyst, characterized in that the support body is a metal foam and the metal is selected from the group consisting of cobalt, nickel and copper and mixtures thereof.

Method for the preparation of C&#x2014;C-alcohols by catalytic hydrogenation of the corresponding aldehydes

The invention relates to a process for preparing an ester mixture, in which an n-butene-containing feed mixture having a composition which changes over time is first oligomerized and then converted by hydroformylation, hydrogenation and esterification to an ester mixture. In this process, an approximation of the actual viscosity of the ester mixture is determined. The problem that it addresses is that of specifying a comparatively simple process which enables conversion of an n-butene with a variable composition over time to an ester mixture having a viscosity which can be kept very substantially constant over a long period even when an inconstant Csource which delivers fluctuating qualities over this period is utilized. This is achieved through controlled use of a second raw material, namely ethene. It has been found that the viscosity of n-butene-based ester mixtures can be influenced by controlled use of ethene in the preparation of the ester precursors. Specifically, the invention proposes two measures by which the ethene can be used: either directly as Colefin or as Colefin after prior separate oligomerization.

Influencing the viscosity of N-butene-based ester mixtures by controlled use of ethene in the preparation of the ester precursors

The invention is concerned with the issue of how to produce n-pentanal by hydroformylation from feedstock mixtures comprising a small proportion of n-butene and a large proportion of n-butane. Specifically, solutions for further optimizing established processes for hydroformylation of such low-butene mixtures in terms of material utilization are sought. The present invention has for its object to enhance the material utilization of the feedstock mixture in the production of n-pentanal from feedstock mixtures having a small proportion of n-butene and a large proportion of n-butane. The process shall be capable of economic operation on an industrial scale. In particular an existing oxo plant shall be honed to achieve better raw material utilization. This object is achieved by a combination of a hydroformylation and a dehydrogenation, wherein said combination has the special feature that the dehydrogenation is arranged after the hydroformylation in the downstream direction and is thus markedly smaller than conventional dehydrogenations provided upstream. A skillful product removal effectively removes contaminants formed in the process.

Production of n-pentanal from low-butene feedstock mixtures

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Dorsten, Germany

Lena Altmann