Abstract: A highly energy efficient process for removing hydrocarbons from polymer slurries is disclosed. The process includes feeding a hydrocarbon-containing polymer slurry to a flash tank to flash a portion of the hydrocarbon from the slurry. Thereafter, the resulting slurry is fed to a fluid bed dryer wherein additional hydrocarbon is stripped from the polymer. Subsequently, the resulting polymer powder is transferred to a powder silo wherein further hydrocarbon is removed from the polymer utilizing a heated purge gas flowing countercurrent to the polymer powder. The polymer output preferably has a low hydrocarbon content, on the order of 100 ppm or less.

Abstract: Methods and apparatus for the removal of hydrocarbons from polymer slurries are disclosed. The invention includes feeding a hydrocarbon-containing polymer slurry to a flash tank to flash a portion of the hydrocarbon from the slurry. A fraction of the residual slurry is circulated through a heating means and recirculated back to the flash tank to flash additional hydrocarbon from the slurry. The invention is applicable to remove isobutane solvent from an aqueous polyethylene slurry. It is also applicable to the removal of other hydrocarbons, including solvents, monomer and comonomer from polymer slurries.