Method for the solvent extraction of polychlorinated biphenyls
AssigneeThe Franklin Institute
InventorsLouis J. Pytlewski, Edward J. Thorne
Life of this patent
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Abstract
A process for the removal and detoxification of polychlorinated biphenyls (PCBs) present in dielectric or other fluids, such as transformer oil, employing polyethylene glycol as the primary extractant, cyclohexane as a secondary extractant and a reagent derived from the reaction of sodium or sodium hydroxide, polyethylene glycol and oxygen for the decomposition and detoxification of the PCBs.
Claims33
A process for the removal of polychlorinated biphenyls from a fluid containing the same which comprises:
- contacting said fluid with polyethylene glycol for a period of time sufficient for said glycol to selectively extract at least a portion of the chlorinated biphenyl compounds from said fluid;
- and
- separating the polyethylene glycol and extracted polychlorinated biphenyls from said fluid.
A process for the removal of polychlorinated biphenyl from the dielectric fluid of an electrical transformer which comprises:
- drawing off dielectric fluid from said transformer;
- contacting said drawn off fluid with polyethylene glycol for a period of time sufficient for said glycol to selectively extract at least a portion of the polychlorinated biphenyl from said fluid;
- separating from said fluid the polyethylene glycol containing extracted polychlorinated biphenyl;
- and returning said fluid to said transformer.
A process for removing and detoxifying a polychlorinated biphenyl present in the dielectric fluid of an electrical transformer which comprises:
- drawing off dielectric fluid from said transformer;
- contacting said drawn off fluid with polyethylene glycol in a primary extraction operation for a period of time sufficient for said glycol to selectively extract at least a portion of the chlorinated biphenyl from said fluid;
- separating from said fluid the polyethylene glycol containing extracted polychlorinated biphenyl;
- returning said fluid to said transformer;
- solvent extracting with cyclohexane the chlorinated biphenyl compound from the polyethylene glycol in a secondary extraction operation to form a cyclohexane-polychlorinated biphenyl extract;
- separating said cyclohexane-polychlorinated biphenyl extract from said polyethylene glycol and recycling the latter to said primary extraction operation;
- removing cyclohexane from said cyclohexane-polychlorinated biphenyl extract and dehalogenating the remaining polychlorinated biphenyl;
- and
- recycling said cyclohexane to said secondary extraction operation.
A process for removing and detoxifying polychlorinated biphenyls present in a fluid containing the same which comprises contacting the fluid with a treating composition comprising polyethylene glycol and a dehalogenation reagent produced by the reaction of an akali metal or alkali metal hydroxide, with polyethylene glycol and oxygen, and extracting the polychlorinated biphenyls in the fluid into said composition;
- introducing oxygen into said composition containing said polychlorinated biphenyls, thereby to effect dehalogenation of the polychlorinated biphenyls by the dehalogenated reagent;
- and
- separating any remaining treating composition and components thereof and, dehalogenation reaction products from said fluid.
Dependencies are inferred from the claim text.