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RUS Patents



Patent Number: Patent No. 2146670

Priority: April 29, 1998

March 20, 2000

Method of continuous, non-emulsion cumene oxidation with air wherein the process is conducted in absence of initiators, catalysts, additives, or alkaline agents in the cascade consisting of at least two reactors in two steps. At the first step the cumene conversion is kept not below 16%, the temperature is kept not above 111-95. The process is conducted in countercurrent reactor with pure cumene not containing alkaline agents. The oxidation products after the first oxidation step are treated with NH4OH solution to get pH not below 8. If at the second step there are two or more reactors the oxidation products are treated with water in each reactor consequently. The cumene conversion at the second oxidation step is kept not higher than 25% mole, the temperature is kept not below 100-85, the oxidation feed and oxidizing agents are added concurrently. In all the reactors of the first and second step the pressure is kept not below 4 (excess pressure), and the ratio of the numbers of the fed oxygen moles to the maximum number of consumed oxygen moles (R) is kept in the range of 1.12 to 1.30. The oxidation products from the last oxidation reactor of the first step are subject to the distillation to produce technical CHP containing 63-93 wt.% of CHP. Recycle cumene obtained in the process of oxidation products distillation is treated with aqueous ammonia solution to get pH of 9-10. The obtained recycle cumene from the hydrogenation stage and fresh cumene are treated with a mixture consisting of 5-10% aqueous NaOH solution and 5-10% aqueous sodium carbonate solution. The joined recycle cumene and fresh cumene streams are treated with water at cumene-to-water ratio of 1 : 0.15-0.20. The technical effect is that high productivity is obtained (CHP formation rate is 2.5-4.5% per hour), the selectivity being kept not below 94 mole % at cumene conversion of 21-22 mole%.




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