Purification of alkylated anthraquinones
AssigneeFMC Corporation
InventorsNathan D. Lee, Dalbir S. Sethi
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Abstract
The invention is for a process for removing unalkylated anthraquinones from alkylated anthraquinone by forming a solution thereof, reducing the solution sufficiently so that at least part of the unalkylated anthraquinone is in the reduced form, and extracting the reduced solution in the absence of an oxidizing agent with an aqueous alkaline solution. The process is especially suited for removing anthraquinone from an alkylated anthraquinone for use in the manufacture of hydrogen peroxide by reducing and oxidizing a solution of the alkylated anthraquinone.
Claims24
The process for purifying a nonaqueous solution of an impure alkylated anthraquinone containing an unalkylated anthraquinone as an impurity comprising reducing said solution sufficiently to convert at least part of the unalkylated anthraquinone to a reduced form and contacting said solution in the absence of oxygen with an alkaline, aqueous solution whereby reduced unalkylated anthraquinone is extracted from the nonaqueous solution.
A process for purifying an impure alkylated anthraquinone containing an unalkylated anthraquinone comprising dissolving the impure alkylated anthraquinone in an inert solvent or mixture of solvents to form a solution thereof, reducing said solution sufficiently to convert at least part of the unalkylated anthraquinone to the reduced form, and contacting said reduced solution in the absence of oxygen with an alkaline, aqueous solution selected from the group consisting of sodium hydroxide and potassium hydroxide whereby unalkylated anthrahydroquinone is extracted from the solution of alkylated anthraquinone.
In the process for manufacturing hydrogen peroxide by the reduction and oxidation of a working solution containing an alkylated anthraquinone in a solvent or mixture of solvents, the improvement which comprises purifying the alkylated anthraquinone by dissolving said alkylated anthraquinone in a solvent to form a solution thereof, reducing said solution sufficiently to convert at least part of the unalkylated anthraquinone to the reduced form, and contacting said reduced solution in the absence of oxygen with an alkaline, aqueous solution whereby the reduced unalkylated anthraquinone is extracted from the solution of alkylated anthraquinone.
Dependencies are inferred from the claim text.