Process for the removal of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and sticky substances from secondary fibers

摘要

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 carbon dioxide or 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% of PCDD's or PCDF's and about 70% to 95% of stickies have been achieved with the technique.