Method for removing polychlorinated dibenzodioxins and polychlorinated dibenzofurans and stickies from secondary fibers using supercritical propane solvent extraction
US5074958A · kind A · utility
5Cited by
29References
25Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1991 |
| Grant date | Dec 24, 1991 |
| Priority date | — |
| Expiry date | Apr 15, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S162/04
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for removing stickies and/or 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 propane for a period of time sufficient to extract a substantial portion of the stickies and/or PCDD's and PCDF's without substantially damaging the fibers. Extraction efficiencies of up to 95% for PCDD's or PCDF's and of about 70% to 95% for stickies have been achieved with the technique.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.