Process for recovery of residual hydrogenation catalyst from hydrogenated nitrile rubber solution
AssigneeZeon Chemicals L.P.
InventorsSoobum Choi, Lawrence J. Justice, Mahesh Datla, Mike Recchio
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Abstract
Residual hydrogenation catalyst produced from reduction of nitrile rubber is recovered by a chelation step using a chelating agent and a series of extraction using semi-coagulation with polar solvents and an optional washing steps for the separation of catalyst-chelating agent complex from hydrogenated nitrile rubber solution. The chelating agent is selected from xanthate, dithiocarbamate, and trithiocarbonate compounds.
Claims15
A process for recovering a metal catalyst from hydrogenated nitrile rubber solution comprising:
- a chelation step using a chelating agent selected from a xanthate, a diothiocarbamate, or a trithiocarbonate compound;
- an extraction step using semi-coagulation;
- and an optional washing step using an organic solvent.
A process for recovering a metal catalyst from hydrogenated nitrile rubber solution comprising:
- a chelation step using a chelating agent selected from a xanthate, a diothiocarbamate, or a trithiocarbonate compound;
- an extraction step using semi-coagulation;
- and an optional washing step using an organic solvent, wherein the metal catalyst is selected from a palladium, platinum, rhodium, or ruthenium catalyst;
- wherein the hydrogenated nitrile rubber solution is composed of hydrogenated nitrile rubber, metal catalyst, and an organic solvent;
- wherein the extraction step using semi-coagulation is obtained by a polar solvent to separate a metal catalyst-chelating agent complex from the hydrogenated nitrile rubber solution;
- wherein the hydrogenated nitrile rubber contained in the solution is about 1% to about 20% by weight;
- wherein the extraction step using semi-coagulation, washing step, and a second extraction step using semi-coagulation are conducted in order to improve recovery of metal catalyst;
- wherein the extraction step using semi-coagulation and washing step are simultaneous;
- wherein polar solvents for the semi-coagulation are selected from water, methanol, ethanol, and isopropanol;
- wherein the organic solvent is selected from a ketone or an ether;
- wherein the ketone is selected from acetone, methyl ethyl ketone, diethyl ketone, and methyl isopropyl ketone.
Dependencies are inferred from the claim text.