Liquid membrane catalytic scale dissolution method
US5032280A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 1990 |
| Grant date | Jul 16, 1991 |
| Priority date | — |
| Expiry date | Mar 14, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K8/528
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A liquid membrane method for removing scale deposits wherein a novel chelating composition is utilized. The composition used in the external and internal aqueous phases of said membrane comprises an aqueous solution having a pH of about 8 to about 14, and a polyaminopolycarboxylic acid chelant. Additionally, a catalyst or synergist is used in the external phase only. Preferred chelants comprise diethylenetriaminepentaacetic acid (DTPA) or ethylenediaminetetraacetic acid (EDTA), salts, and mixtures thereof. The catalyst used in the external phase comprises an oxalate anion. When the solution containing the composition is contacted with a surface containing a scale deposit, the deposit dissolves substantially more scale quicker then heretofore possible.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.