Double-tower high-efficiency energy-saving rectification process

Abstract

The invention belongs to the technical field of separation of chemical substances, and discloses a double-tower high-efficiency energy-saving rectification process which comprises the following steps: step 1, feeding a liquid to be purified into a crude distillation tower, and heating the liquid in a tower kettle by using a heating medium to form mixture steam at the tower top; step 2, condensing the mixture steam at the top of the crude distillation tower to form a vapor phase and a liquid phase, and backflowing the liquid phase to the crude distillation tower, wherein the product content of the extracted product in the mixture steam is 80-95%; and step 3, introducing the vapor phase formed in the step 2 into the rectification tower for rectification, and condensing tower top vapor in the rectification tower to obtain a high-purity product. The problems that in the prior art, due to the fact that the purity of a product led out from a single rectifying tower is high, the bubble point of a chemical product is low, the temperature of a cooling medium needed for cooling is low, the preparation cost of the low-temperature cooling medium is high, and the rectifying cost is high are solved.

Description

technical field [0001] The invention belongs to the technical field of separation of chemical substances, and in particular relates to a double-tower high-efficiency energy-saving rectification process. Background technique [0002] During the production process of chemical products, since the chemical products contain impurities, in order to meet the subsequent production and application, purification treatment is required. [0003] For the chemical products whose dew point is below 40°C, the reflux is relatively large and the cooling capacity needs to be large, the current commonly used purification process is to use a single rectification tower to carry out rectification and purification of the chemical products to be purified. [0004] With the progress and development of the industry, the requirements for the purity of chemical products are getting higher and higher. In order to meet the requirements of the industry, the common way is to increase the purity of chemical ...

AI Technical Summary

Problems solved by technology

[0005] The present invention intends to provide a double-tower high-efficiency energy-saving rectification process to solve the problem of low bubble point of chemical products and low temperature of cooling medium required for cooling due to high product purity derived from a single rectification tower in the prior art. However, the preparation cost of low-temperature cooling medium is relatively high, which leads to the problem of high cost of rectification