Selective decomposition method of cymene oxidation product and application thereof

Abstract

The invention discloses a selective decomposition method of a cymene oxidation product, which comprises the following steps: under the catalysis of strong alkaline ion exchange resin, carrying out selective decomposition reaction on PCHP in the cymene oxidation product to obtain a product with retained TCHP; the cymene oxidation product contains PCHP (polycaprolactone) and TCHP (trichloroisocyanuric acid). According to the method, the strongly alkaline ion exchange resin is used as the catalyst, so that the generation of a large amount of alkali-containing wastewater is avoided, the method is more environment-friendly, the entrainment of alkaline substances in the product is avoided, and the subsequent reaction is easier to carry out. The invention also discloses a production process of cresol, which adopts the decomposition method as a step, reduces the generation of alkali-containing wastewater, and is more suitable for industrial production.

Description

technical field [0001] The invention belongs to the field of production of chemical intermediates, and relates to a production method of cresol and its intermediates, in particular to a selective decomposition method of cymene oxidation products and its application. Background technique [0002] The oxidation products of cymene contain TCHP (tertiary hydroperoxide of cymene) and PCHP (primary hydroperoxide of cymene). Further acidolysis and hydrogenation of TCHP can obtain the important chemical intermediate cresol. Cresol is an important raw material for the synthesis of BHT (2,6-di-tert-butyl-p-cresol), anisaldehyde, p-hydroxybenzaldehyde and other fine chemical products. If PCHP undergoes acidolysis reaction with TCHP, it will be decomposed into propophenol and formaldehyde, and formaldehyde will undergo phenolic condensation reaction with TCHP reaction product cresol, thereby affecting the yield of cresol. Wherein, the structural formulas of TCHP and PCHP are as follows...

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Problems solved by technology

Sumitomo Chemical Industry Co., Ltd. subsequently provided a relatively complete cresol production process in CN1079952A, wherein the treatment of the hydroperoxide mixture uses liquid alkali and additives to selectively decompose the cymene oxidation product, which can be processed at a higher rate. Selectively decompose PCHP while retaining TCHP, but the product needs to be phase-separated and washed to remove alkali. There are many steps and the operation is cumbersome. At the same time, the operation is intermittent

[0009] Sumitomo Chemical Industry Co., Ltd. further discloses a post-treatment method of a hydroperoxide mixture in CN1058002C, which mentions that although the previously reported method (alkali and organic quaternary ammonium salt) has higher selectivity, the organic quaternary ammonium The anion of salt can be harmful to equipment, and also can produce the amine compound that is difficult to separate, has proposed to adopt alkali metal hydroxide or alkaline earth metal hydroxide (solution) to be catalyst, add metal carboxylate as auxiliary agent to carry out decomposition reaction, The decomposition rate of PCHP can reach 99%, and the retention of TCHP can reach more than 96%. This method still uses an excessive amount of aqueous inorganic alkali solution, which requires phase separation; and in order to ensure the stability and safety of subsequent steps, an additional step of organic phase pickling or In the process of washing and removing alkali, the product will be partially lost

[0010] The above-mentioned patents all use the method of mixing alkali solution and oxidation product to carry out the selective decomposition reaction of PCHP. This method has the following disadvantages: 1. It needs clarification, phase separation and post-washing treatment, and the operation is cumbersome; 2. The alkali solution may It will be entrained in the oxidation product, consume the catalyst (sulfuric acid) in the acidolysis process, so that the acidolysis reaction cannot be carried out effectively, and the residual peroxide concentration is high, which brings a greater safety hazard; 3. The reaction is carried out by adding alkaline water After staying for a certain period of time, it is an intermittent operation; 4. The alkali solution is used as a catalyst. After the reaction, a large amount of strong alkaline wastewater will be produced, and a large amount of acid will be consumed to neutralize it.

[0011] Regarding the entrainment problem of alkali in the above-mentioned second point, CN1764637A specifically records the phenomenon of treating the reaction product containing organic hydroperoxide with alkaline aqueous solution, and proposes a solution to wash with water, which requires special equipment and process, the cost is higher, and the problem of treating organic hydroperoxides with lye is not fundamentally solved

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