Recovery of rhodium from carbonylation residues
US4341741A · kind A · utility
15Cited by
22References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1981 |
| Grant date | Jul 27, 1982 |
| Priority date | — |
| Expiry date | Mar 6, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/584
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. Such residues contain noble metal, typically rhodium, used as a catalyst, which must be recovered before the residues can be disposed of. The rhodium values are freed from the residues by treatment with amines, preferably primary aliphatic amines and/or hydrazine, thereby enabling the rhodium to be extracted by subsequent contact with an aqueous halogen acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.