Secondary fiber cellulose product with reduced levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans
US5213660A · kind A · utility
17Cited by
23References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Feb 28, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W30/64
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for removing PCDD's and PCDF's from cellulose-containing fibers such as waste paper is provided. The process comprises contacting the fibers with supercritical or near supercritical carbon dioxide for a period of time sufficient to extract a substantial portion of the PCDD's and PCDF's without substantially damaging the fibers. Extraction efficiencies of greater than 95% have been achieved with the technique.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.