Allied Chemical Corporation

Allied Corporation

Fred W Koff

Stylianos Sifniades

Allen A Tunick

Robert Fuhrmann

John Pisanchyn

Reed H Belden

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.

Decomposition of cumene oxidation product

A process for separating hydroxylamine from an aqueous solution containing hydroxylammonium salts in mixture with salts of predominantly monovalent cations whose corresponding free bases have base dissociation constants greater than 10.sup.-7. Said solution is passed through a bed of cation exchange resin loaded predominantly with monovalent cations whereby hydroxylammonium and the other cations in solution substantially displace said cations from the resin. A second aqueous solution containing a monovalent amine or hydroxide base of at least 0.5 molar concentration having a dissociation constant greater than 10.sup.-7 is passed through the resin bed whereby hydroxylamine is preferentially released to the solution and the resin is correspondingly loaded with the cation of said base. Hydroxylammonium salts can be crystallized from the solution after addition of a stoichiometric amount of an appropriate acid.

Hydroxylamine purification via cation exchange

A process for obtaining hydroxylammonium salts from aqueous solutions containing hydroxylammonium salts in mixture with ammonium and/or sodium salts. Said solutions are contacted with a water immiscible organic solution containing a cation exchange compound of structure R.sub.1 COOX, or (R.sub.2 O)(R.sub.3 O)POOX, or (R.sub.2 O)PO(OX).sub.2, or mixtures thereof and optionally an additive of structure R.sub.4 R.sub.5 R.sub.6 PO, or (R.sub.4 O)(R.sub.5 O)(R.sub.6 O)PO, or mixtures thereof, wherein R.sub.1 is an alkyl or alkenyl group of from twelve to twenty carbon atoms, R.sub.2 and R.sub.3 are alkyl groups of from six to eighteen carbon atoms, R.sub.4, R.sub.5 and R.sub.6 are alkyl groups of from three to twelve carbon atoms, and X is H, Na or NH.sub.4, whereby hydroxylammonium ions are preferentially extracted from the aqueous phase in exchange for X from the organic phase. Said organic solution is subsequently contacted with an aqeuous solution of a strong acid, whereby hydroxylammonium ions are extracted into the aqueous phase. Hydroxylammonium salts are obtained by crystallization from said aqueous phase.

Hydroxylamine purification via liquid/liquid extraction

A process for separating hydroxylamine from an aqueous solution thereof also containing salts of cations whose corresponding free bases have base dissociation constants greater than 10.sup.-7. Said solution is brought to a pH of 6-11 and is passed through a bed of strongly ionic exchange resin loaded with compensating ions whereby hydroxylamine is retained in the gel volume of the resin bed and the ions in solution are substantially excluded from the resin. The ionic salts accordingly move faster through the bed and predominate in a first effluent fraction and the hydroxylamine appears predominantly in a later effluent fraction. Hydroxylammonium salts can be crystallized from the effluent hydroxylamine solution after addition of a stoichiometric amount of an appropriate acid.

Hydroxylamine purification via ion exclusion

Purification of chloronitrosocyclohexane dimer (CNCD) is effected by dissolving the crude CNCD in a chlorinated aliphatic hydrocarbon or a lower aromatic hydrocarbon solvent and thereafter displacing the solvent of the solution with an aliphatic alcohol of higher boiling point. Pure CNCD crystallizes and is separated from the liquors, which retain colored matter and other impurities.

Purification of chloronitrosocyclohexane dimer (CNCD)

Cyclo-olefins are converted in high yield to the corresponding chloro-nitroso dimers by dissolving the cyclo-olefin in liquid SO.sub.2 and contacting with NOCl while maintaining a substantially oxygen-free environment. Even higher yields are attained by controlling the gradual addition of the NOCl and by using a molar ratio of NOCl to cyclo-olefin of less than about 0.92:1.

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Long Valley, NJ, United States of America

Fred W Koff