Process for the removal of selenium compounds from urethane solutions
AssigneeAtlantic Richfield Company
InventorsRudolph Rosenthal, Edward T. Shawl
Life of this patent
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Abstract
A process for the recovery of selenium from a urethane solution containing selenium compounds which comprises contacting the selenium-containing urethane solution at a suitable temperature with copper (I) chloride, oxygen or an oxygen-containing gas such as air, and a complexing solvent such as an amine or nitrile to form an insoluble precipitate of copper-selenium compounds or complexes. The selenium and copper may be recovered from the resulting precipitate in a form suitable for reuse in the preparation of urethanes and selenium removal respectively.
Claims12
A process for the recovery of selenium from selenium-containing urethane solutions derived from the selenium catalyzed reaction of an organic compound containing at least one hydroxyl group with carbon monoxide and a nitrogenous organic compound at elevated temperatures and pressures in the presence of a base and/or water, which comprises the steps of:
- contacting the selenium-containing urethane solution at a temperature in the range of from about ambient to about 150.degree. C. with copper (I) chloride at a weight ratio of copper to contained selenium of about 1:10, from about 5 to about 50 parts by weight based on urethane solution treated of an alkyl, aryl or aralkyl amine or alkyl, aryl or substituted aryl nitrile complexing solvent, and oxygen or an oxygen-containing gas at a pressure of from about 0.1 to about 5 atmospheres to form an insoluble copper-selenium compound or complex precipitate in solution;
- separating the insoluble precipitated compound or complex from the solution;
- treating said insoluble copper-selenium compound or complex with air or oxygen at a temperature of from about 300.degree. C. to 650.degree. C. to convert the selenium to selenium dioxide and the copper to copper oxide to separate selenium and copper;
- and
- recovering said copper oxide and selenium dioxide.
A process for the recovery of selenium from a selenium-containing diethyl toluene-2,4-dicarbamate solution derived from the selenium catalyzed reaction of ethyl alcohol with carbon monoxide and 2,4-dinitrotoluene at elevated temperature and pressure in the presence of a base and/or water which comprises the steps of:
- contacting the selenium-containing diethyltoluene-2,4-dicarbamate solution at a temperature in the range of from about ambient to about 150.degree. C. with copper (I) chloride at a weight ratio of copper to contained selenium of about 1:10, from about 5 to about 50 parts by weight based on urethane solution treated of an amine or nitrile complexing solvent, and oxygen or an oxygen-containing gas at a pressure of from about 0.1 to about 5 atmospheres to form an insoluble copper-selenium compound or complex precipitate in solution;
- separating the insoluble precipitated compound or complex from the solution;
- treating said insoluble copper-selenium compound or complex with air or oxygen at a temperature of from about 300.degree. C. to 650.degree. C. to convert the selenium to selenium dioxide and the copper to copper oxide to separate selenium and copper;
- and
- recovering said copper oxide and selenium dioxide.
Dependencies are inferred from the claim text.