Method and device for detecting and controlling acetoacetic ester continuous reaction system on line

Abstract

The invention provides a method and device for detecting and controlling an acetoacetic ester continuous reaction system on line. The method comprises the following steps of: proportionally controlling the inventory ratings of diketene and fatty alcohol for undergoing an esterification reaction; testing the refractive index and the reaction temperature of the reaction system on line; establishing a neural network soft measurement model for indirectly measuring the concentration of a main component in a reaction kettle according to the refractive index, the content of acetic anhydride in fed diketene and the reaction temperature; and correcting and controlling a flow proportion controller based on the model so as to realize online detection and control of the acetoacetic ester continuous reaction system. By adopting the method and the device, the concentration of the main component in the reaction system can be monitored in real time in an acetoacetic ester continuous preparation process, an abnormal reaction condition is avoided, raw material input quantity proportion can be correspondingly controlled in time according to real-time detection data simultaneously, the concentration of the main component in the reaction system is kept in a normal process range, and the acetoacetic ester continuous preparation process is further optimized.

Description

technical field [0001] The invention relates to an online detection and control method and device of an acetoacetate continuous reaction system. Background technique [0002] Acetoacetate is an important chemical and pharmaceutical intermediate, which can be used in the synthesis of medicines, pesticides, vitamins and chemical raw materials. At present, the research on the preparation process of acetoacetate is generally a batch production process, which mainly includes: adding a certain amount of alcohol and catalyst into the reactor, then adding diketene dropwise, gradually increasing the temperature, and gradually adding dropwise accurately according to the actual reaction situation. For the measured diketene, wait for the feed liquid to be added dropwise, and only after the reaction is completed can chromatographic analysis be carried out to further confirm the reaction situation. However, with the continuous expansion of acetoacetate production capacity, the shortcomin...

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Problems solved by technology

[0004] In the existing acetoacetate preparation process, the production scale of a single batch batch reaction device is small and the operation is cumbersome, and it is easy to misuse and cause danger. The acetic anhydride in the reaction crude product is difficult to remove by rectification, and if concentrated sulfuric acid or Acetoacetate is easily decomposed by a strong base to remove acetic anhydride, leading to defects such as a decrease in product yield. Therefore, the inventor has developed a continuous preparation process for acetoacetate through a large number of experimental studies.

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