The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 22, 2017
Filed:
May. 07, 2014
Basf SE, Ludwigshafen, DE;
Stefanie Demming, Mannheim, DE;
Suman Thotla, Mannheim, DE;
Jens Wittenberg, Limburgerhof, DE;
Gabriele Iffland, Heidelberg, DE;
Christian Brueggemann, Mannheim, DE;
Yvonne Hoelzl, Raleigh, NC (US);
Wolfgang Siegel, Limburgerhof, DE;
Stephan Freyer, Neustadt, DE;
BASF SE, Ludwigshafen, DE;
Abstract
The invention relates to a process for continuously preparing di-C-alkyl succinates by reacting succinic acid with an C-alkanol in the presence of a fixed-bed heterogeneous acidic esterification catalyst in a tubular reactor at a temperature in the range of from 60 to 100° C., wherein a mixture, comprising succinic acid, C-alkanol, mono-C-alkyl succinate, di-C-alkyl succinate and water, is formed in a mixing stage and fed to the entrance of the tubular reactor, and wherein 5 to 75% of the outlet flow rate of the tubular reactor are recycled directly to the mixing stage as a recycle stream, and the molar ratio of C-alkanol to succinic acid added to the mixing zone, and not including the C-alkanol and succinic acid at the recycle stream, being in the range of from 2.0 to 9.5. The invention furthermore relates to a process for separating the reactor effluent of an esterification of succinic acid with an C-alkanol to give di-C-alkyl succinates by distillation, wherein the separation is performed in a divided wall column in which C-alkanol and water are removed in a top draw of the column, di-C-alkyl succinate is removed in a side draw of the column, and wherein mono-C-alkyl succinate and succinic acid are removed in a bottom draw of the column.