Removal of trace arsenic impurities from triethylphosphate (TEPO)
US8039658B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 25, 2008 |
| Grant date | Oct 18, 2011 |
| Priority date | — |
| Expiry date | Jul 30, 2030 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/025
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of removing trace levels of arsenic-containing impurities from raw triethylphosphate (TEPO) is disclosed. The method uses adsorption, or adsorption followed by a flash distillation. The method comprises contacting raw triethylphosphate (TEPO) with an adsorbent which selectively adsorbs the arsenic-containing impurities in the raw triethylphosphate (TEPO). The adsorbent is a base promoted alumina containing adsorbent represented by a formula: ZxWy; where x is the weight percentage of Z in the adsorbent ranging from 30% to 99.999%; y is the weight percentage of W in the adsorbent, and x+y=100%; Z is selected from the group consisting of alumina (Al2O3), magnesium-alumina based layered double hydroxide (MgO—Al2O3), alumina-zeolite, and mixtures thereof; and W is selected from the group consisting of at least one basic metal oxide, at least one basic metal carbonate, and mixtures thereof. The method will result in a final triethylphosphate (TEPO) with a few ppb to less than 1 ppb arsenic containing impurities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.