Method for continuously producing p-menthane hydroperoxide by p-menthane and device thereof

Abstract

The invention relates to a method for continuously producing p-menthane hydroperoxide by p-menthane and a device thereof. The method comprises the following steps of: 1, blowing an oxidizing gas into an oxidizing tower, adding a mixed solution comprising p-menthane and a catalyst radical initiator into the oxidizing tower to ensure that the gas is in fully contact with the p-menthane solution for carrying out oxidizing reaction; 2, carrying out gas-liquid separation on oxidation products, refluxing a part of p-menthane hydroperoxide products to the oxidizing tower, conveying the left p-menthane hydroperoxide products to a cooler from a discharging hole at the middle of a gas-liquid separator through the other branch pipeline, and entering an intermediate storage tank after cooled; and 3, sending the p-menthane hydroperoxide products in the intermediate storage tank into an evaporator for evaporating and concentrating as well as purifying, then cooling and sending into a product storage tank, and refluxing unoxidized products evaporated by the evaporator to a raw material mixing tank. The invention also relates to a device for implementing the method for continuously producing the p-menthane hydroperoxide by the p-menthane. The p-menthane hydroperoxide produced by using the method in the invention has the advantages of high purity, good quality, stable and safe production process and convenient operation.

Description

technical field [0001] The invention relates to a continuous production method and device for preparing p-menthane hydrogen peroxide from p-menthane. Background technique [0002] P-menthane is an important fine chemical product, which is generally obtained from forestry products by hydrogenation of dipentene. [0003] p-Menthane hydroperoxide (English name p-Menthane hydroperoxide, PMHP for short) is an olefin polymerization initiator with excellent performance, mainly used as an initiator for the polymerization of styrene-butadiene rubber. One of the important methods of industrially producing hydrogen peroxide p-menthane is through the oxidation of p-menthane. [0004] At present, the industrial production of hydrogen peroxide from p-menthane mainly adopts batch production process, that is, intermittent oxidation and batch evaporation concentration purification process. For example, in the method that Chinese patent application CN101225067A discloses catalytic air oxida...

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Problems solved by technology

[0005] Batch production process has the following problems: (1) Batch oxidation usually requires the addition of a catalyst for each feeding to achieve the oxidation depth required for production, because it is liquid phase oxidation , the catalyst usually flows out of the reactor together with the reaction product. On the one hand, the reaction product needs to remove the catalyst and impurities before entering the next process; on the other hand, the catalyst is expensive and needs to be recycled. Therefore, it is necessary to purchase special catalyst recovery equipment. , and the removal of the catalyst in the reaction product is quite complicated, and domestic and foreign enterprises engaged in the production of this product need to spend a lot of investment to remove the catalyst in the reaction product; in addition, the discharge of wastewater after the removal of the catalyst will also cause Environmental pollution; (2) In order to improve the purity of the product as much as possible, the oxidation depth must be increased, and the operation procedure is complicated, so there are many potential safety hazards; (3) It is not convenient for automatic control, mainly relying on manual operation. The control accuracy is also poor, so the general production scale is small; (4) Hydrogen peroxide is easy to decompose into alcohol and oxygen when heated, and the batch evaporation concentration purification process is adopted, and the heating time in the evaporation concentrator is long, and it is easy to decompose. Product color deepens

[0006] There are also fixed-bed continuous production processes now, but there are two main problems in the production equipment: (1) Structural problems of the oxidation tower: the oxidation tower uses disks Tube gas supply (oxygen, air or mixed gas of oxygen and air) device, a small hole with a diameter of about 2 mm is opened on the coil as a gas outlet hole. Large, small specific surface area, low gas utilization rate; second, because the pores are large, it is easy to cause the local gas concentration in the liquid outside the tube to be too high or the liquid enters the tube to cause the local liquid concentration in the gas to be too high and reach the explosion limit (in the Meng Under the set temperature and pressure of the alkoxylation reaction, it is safer to control the concentration of hydrogen peroxide to menthane not exceeding 20%, which will cause safety hazards; (2) evaporator structural problems: hydrogen peroxide is a heat-sensitive material to menthane , in addition to being easy to decompose and deepen the color of the product after a long heating time, the local concentration is too high to bring safety hazards, so different from the evaporation of general materials, the traditional structure of the evaporator cannot effectively solve the problem of hydrogen peroxide on the safety and stability of Menthane enrichment problem

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