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:
May. 22, 2018
Filed:
Sep. 23, 2015
Invista Technologies S.Ă R.l., Gallen, CH;
Alan Macpherson Ure, Redcar, GB;
Antony Peter John Limbach, Redcar, GB;
INVISTA NORTH AMERICA S.A.R.L., Wilmington, DE (US);
Abstract
The present invention provides a process for the production of an aromatic dicarboxylic acid comprising the catalytic oxidation of a hydrocarbon precursor in an organic solvent, comprising the steps of: i) separating a vent gas from an oxidation stage into an organic solvent-rich liquid stream and a water-rich vapor stream in a distillation stage; and ii) separating an aqueous purification mother liquor comprising organic compounds from purified aromatic dicarboxylic acid crystals in a separation stage, characterized in that the process further comprises the steps of: iii) transferring the aqueous purification mother liquor from the separation stage to an extraction stage; iv) extracting said organic compounds from the aqueous purification mother liquor by contacting the aqueous purification mother liquor at a temperature of at least 90° C. with an organic liquid in the extraction stage to form an aqueous phase and an organic phase, wherein the concentration of said organic compounds in the aqueous phase is lower than the concentration of said organic compounds in the aqueous purification mother liquor; and v) transferring the aqueous phase to said distillation stage. The present invention further provides an apparatus for carrying out the process.