Patent · US Expired

Process for the recovery of an organic acid from the manufacture of a cellulose ester

US5648529A · kind A · utility

4Cited by
4References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 16, 1995
Grant dateJul 15, 1997
Priority date
Expiry dateMay 16, 2015

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P20/10
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

The present invention is directed to a process for the recovery of an organic acid. The organic acid is generated from the manufacture of a cellulose ester. The first step of the process is to remove the organic acid from the manufacture of cellulose ester. The acid is in the form of a weak acid stream comprising of the organic acid and water. The weak acid stream is resolved, via a solvent extraction, to form an extractor overhead stream and raffinate stream. The raffinate stream comprises solvent, water, and alcohol. The alcohol is produced in the recovery process by hydrolysis of the solvent after the solvent extraction. The raffinate stream is resolved into a overhead stream and a bottom stream. The overhead stream comprises water, alcohol, and solvent. Excess organic acid is added to the overhead stream to form a feed stream. The feed stream is catalyzed, via ion exchange resins, whereby a portion of the alcohol is esterified to the solvent. The solvent, thus produced, is recycled into the recovery process.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.