Method for removing hydrocarbons from polymer slurries
AssigneeQuantum Chemical Corporation
InventorsChieh-Yuan F. Sung, Stephen J. Krause
Life of this patent
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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.
Claims27
A process for removing a hydrocarbon from a polymer slurry comprising the steps of:
- feeding a hydrocarbon-containing polymer slurry to a flash tank to flash a portion of the hydrocarbon from the slurry;
- circulating at least a portion of the polymer slurry from the flash tank through heating means to heat the slurry to a temperature above the operating temperature of the flash tank, and recirculating the heated slurry to the flash tank to flash additional hydrocarbon from the slurry;
- and
- collecting from said flash tank slurry having a substantially lower hydrocarbon content than the slurry fed to the flash tank.
A process for removing a hydrocarbon from a polymer slurry comprising the steps of:
- feeding a hydrocarbon-containing polymer slurry to a first flash tank to flash a portion of the hydrocarbon from the slurry;
- feeding the resulting slurry from the first flash tank to a second flash tank to flash additional hydrocarbon from the slurry, said second flash tank being operated at a lower pressure than said first flash tank;
- feeding the resulting polymer slurry from the second flash tank to a third flash tank to flash additional hydrocarbon from the slurry, said third flash tank being operated at a lower pressure than either of said first or second flash tanks;
- circulating at least a portion of the polymer slurry from the third flash tank through heating means to heat the slurry to a temperature above the operating temperature of the third flash tank, and recirculating the heated slurry to the third flash tank to flash additional hydrocarbon from the slurry;
- and
- collecting from said third flash tank slurry having a substantially lower hydrocarbon content than the slurry fed to the third flash tank.
In a process for removing a hydrocarbon from a polymer slurry including the steps of feeding the hydrocarbon-containing polymer slurry to a first flash tank to flash a portion of the hydrocarbon from the slurry, and feeding the resulting slurry from the first flash tank to a second flash tank to flash additional hydrocarbon from the slurry, wherein the second flash tank is operated at a lower pressure than the first flash tank, the improvement comprising:
- feeding the resulting polymer slurry from the second flash tank to a third flash tank to flash additional hydrocarbon from the slurry, said third flash tank being operated at a lower pressure than either of said first or second flash tanks;
- circulating at least a portion of the polymer slurry from the third flash tank through heating means to heat the slurry to a temperature above the operating temperature of the third flash tank, and recirculating the heated slurry to the third flash tank to flash additional hydrocarbon from the slurry;
- and
- collecting from said third flash tank slurry having a substantially lower hydrocarbon content than the slurry fed to the third flash tank.
Dependencies are inferred from the claim text.