Continuous production of benzoic acid by benzyl benzoate low boiling
Benzoic acid is a scaly or acicular crystal with benzene or formaldehyde odor. Its vapor has strong irritation and absorption. It causes cough easily, soluble in water, and in organic solvents such as ethanol and ether. Benzoic acid is weak acid and stronger than fatty acid. Their chemical properties are similar to each other and can form salt, ester, acylhalogen, amide, anhydride and so on. Benzoic acid is widely used in industrial chemicals and is widely used in toluene oxidation to benzoic acid, considering the raw material price, safety, waste treatment, and environmental impact factors, the use of benzyl benzoate low boiling production of benzoic acid has greater advantages. The problem is that when benzoic acid is attached to the inner wall of the crystallization kettle, the heat transfer efficiency becomes worse and the freezing crystallization time becomes longer, which affects the production efficiency. Because the crystallization kettle is conical, it is difficult to make a pressure vessel, and then steam into the jacket to melt benzoic acid on the wall of the kettle. In order to overcome the below disadvantage, we could use a system for continuous production of benzoic acid by benzyl benzoate low boiling, comprises a heat exchanger unit, a crystallization kettle, a centrifuge, a mother liquor tank and a benzoic acid tank. The top of the crystallization kettle is provided with a feeding port which passes through the feeding pipe and the heat exchanger. A full direction agitator is arranged in the crystallization kettle, and an overflow port is arranged at the top of the crystallization kettle. The overflow port is connected with the overflow pipe. The side part of the crystallization kettle is provided with a cooling jacket, the bottom of the crystallization kettle is provided with a discharge port, the discharge port is connected with the discharge pipe, the discharge pipe is connected with the top entrance of the centrifuge after parallel connection with the overflow pipe, the bottom of the centrifuge is provided with a discharge port and a discharge port, the discharge port is connected with the top entrance of the mother liquor tank through the discharge pipe, and the discharge port is connected with the top entrance of the benzoic acid tank through the discharge pipe. The benzyl benzoate containing benzoic acid can be frozen and crystallized continuously, and the higher content of benzoic acid can be obtained by centrifugation.
