Ethyl benzoate, also known as ethyl benzoate, is a colorless transparent liquid, insoluble in water, slightly fruity flavor, mainly used in the preparation of perfume fragrance and artificial essential oil; There is also plenty of food. The traditional synthesis method is to esterify benzoic acid and ethyl ester to form cation exchange resin under sulfuric acid or catalysis. Sulfuric acid is a strong inorganic acid, with serious corrosion, can cause side reactions (such as oxidation, burning, addition), easy to cause environmental pollution, does not meet the current environmental protection requirements. Although Zeo-karb can overcome the disadvantages of sulfuric acid catalysis, the cost is higher. The above two catalysts are used in the production of ethyl benzoate, the conversion efficiency is generally not more than 95%.

Overview of the invention

In order to overcome the shortcomings of the technical problems, the invention provides a preparation method of ethyl benzoate, which can completely solve the above problems.

The technical solutions to the above technical problems are as follows:

The preparation method of ethyl benzoate is as follows:

Add benzoic acid, dehydrating alcohol, modified clay and water-trapping agent into the trap reactor, install the trap valve, return condensing pipe and thermometer on the reactor, carry out the return water separation during heating, and react until only no spheres appear. After cooling at room temperature for 20 minutes, release the water layer, wash the reaction liquid with water, dry and then distillation, and then volatilize the steam in front. The cutting set temperature is 101 ~ 103℃ for the product.

The mass ratio of benzoic acid, dehydrated ethanol and modified clay is 4:3:0.2.

The water clamping agent is any of hexane, benzene or toluene.

Most of the modified clay exists in the crystal of clay, and in the silica, oxygen, aluminum, magnesium atoms, and bedding gaps dispersed with positive sodium and calcium ions. Alkaline earth metal ions such as sodium and calcium ions are easily replaced by h3o +, which erodes salt clay into acidic clay. The integrity of the clay crystals is not compromised, and the acid clay provides two-dimensional access to its interior.

The modified clay used in the invention can improve the conversion efficiency of the charge as a solid acid catalyst from less than 95% to more than 99.5%. In addition, the invention can avoid the addition of sodium carbonate and excessive acid in the liquid catalyst technology and the resulting waste liquid discharge problem.

The preparation method of ethyl benzoate is as follows: