Decomposition of cumene oxidation product
AssigneeAllied Corporation
InventorsStylianos Sifniades, Allen A. Tunick, Fred W. Koff
Life of this patent
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Abstract
A cumene oxidation product containing cumene hydroperoxide (CHP) and dimethylphenylcarbinol (DMPC) is decomposed with acid catalyst in a first step at mild temperatures that lowers the CHP concentration to about 0.5-5% and converts most of the DMPC to dicumylperoxide (DCP). In a second step at mild temperatures the CHP concentration is lowered below 0.4%. In a third step the DCP is decomposed at a higher temperature for a short time to alpha-methylstyrene (AMS), phenol and acetone, with any remaining DMPC also converted to AMS. The DCP concentration is monitored during the third step, and the reaction is stopped by cooling when about 0.5-5% of the DCP remains undecomposed so as to maximize AMS yield.
Claims8
A process of decomposing a cumene oxidation product mixture containing cumene hydroperoxide (CHP) and dimethylphenylcarbinol (DMPC) to produce phenol, acetone and alpha-methyl styrene (AMS) with reduced by-product formation which comprises the steps:
- (a) mixing the cumene oxidation product with an acid catalyst in a back-mix reactor in the presence of about 0.4 to about 4.5% water, by weight of reaction mixture, at a temperature between about 50.degree. C. and about 90.degree. C. for a time sufficient to lower the CHP concentration of the back-mix reaction mixture to between about 0.5 and about 5.0 weight % and to convert at least 40% of the DMPC in the cumene oxidation product to dicumylperoxide (DCP);
- (b) reacting the back-mix reaction mixture at between about 50.degree. C. and about 90.degree. C. under plug flow conditions for a time sufficient to produce a second mixture having a CHP concentration no more than about 0.4;
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- (c) reacting the second reaction mixture at a temperature between about 120.degree. and about 150.degree. C. under plug flow conditions for a time sufficient to convert at least 90% of the DCP to AMS, phenol and acetone.
A method for the production of alpha-methylstyrene in a phenol-acetone-cumene solution which comprises the steps:
- (a) heating a first mixture comprising phenol, acetone, cumene and dicumyl peroxide to a temperature between about 120.degree. C. and about 150.degree. C. under plug flow conditions,
- (b) measuring the dicumyl peroxide concentration,
- (c) cooling the reaction mass to below 100.degree. C. to stop the reaction and reduce by-product formation from alpha-methylstyrene when the dicumyl peroxide concentration is between about 0.5 and about 5.0% of the dicumyl peroxide concentration of said first mixture.
Dependencies are inferred from the claim text.