Process and apparatus for purification of acrylic acid
US10213706B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2015 |
| Grant date | Feb 26, 2019 |
| Priority date | — |
| Expiry date | Jul 30, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C57/04
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process and an apparatus for the purification of a crude acrylic acid composition containing maleic anhydride as an impurity comprising the following steps: (a) carrying out at least one dynamic melt crystallization stage (14, 14a, 14b, 14c, 14d) with the crude acrylic acid composition to prepare a first purified acrylic acid composition and a first residue containing at least 3.5% by weight maleic anhydride, (b) adding a solvent (26) which is capable of dissolving maleic anhydride to the first residue in an amount that the weight ratio of the solvent to the maleic anhydride is 0.3 or more to prepare a ratio-adjusted residue and (c) carrying out at least one further dynamic melt crystallization stage and/or at least one static melt crystallization stage (18, 18a, 18b) with the ratio-adjusted residue to prepare a second purified acrylic acid composition and a second residue.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.