Method for producing sodium acetate trihydrate and anhydrous sodium acetate as byproducts

Abstract

The invention relates to a method for producing sodium acetate trihydrate and anhydrous sodium acetate as byproducts, which comprises the following steps: firstly, taking sodium acetate solution which is a byproduct generated in the production process of trimellitic anhydride, pouring into a material mixing kettle, stirring, and neutralizing until the pH value is 6-9; secondly, evaporating and concentrating; thirdly, putting the concentrated sodium acetate solution in a crystallization kettle, cooling to 60-57 DEG C, adding sodium acetate trihydrate crystals accounting for 0.05-0.5% by mass of the solution in the kettle to provoke the crystallization, and stirring for more than 12 hours; fourthly, centrifugally separating to obtain the solid phase which is the sodium acetate trihydrate; and fifthly, drying the sodium acetate trihydrate in a vortex drier to obtain the anhydrous sodium acetate. The method can prevent the sodium acetate solution from being supercooled, avoids the processes with high energy consumption, such as brine cooling and the like, and does not need to add other crystal nuclei so as to avoid introducing impurities into the product. The vortex drier is used for drying by one step so as to avoid the complicated energy-consuming processes of vacuum concentration, crystallization by cooling, centrifugal separation, drying and the like in the prior production technique of anhydrous sodium acetate.

Description

(1) Technical field [0001] The present invention relates to a kind of method of producing sodium acetate trihydrate and anhydrous sodium acetate, especially the method for by-product sodium acetate trihydrate and sodium acetate when trimellitic anhydride is produced. It belongs to the technical field of organic salt production. (2) Background technology [0002] Sodium acetate (commonly known as sodium acetate) can be used as an esterifying agent in organic synthesis, and can be used in many aspects such as photography medicine, medicine, printing and dyeing mordant, buffer, meat preservation, pigment, tanning and so on. When used as a deicing agent, it is much less damaging to roads than table salt. It acts as a buffer for condiments, which can alleviate bad odors and prevent discoloration of condiments, and has a certain anti-mildew effect. It can also be used to prepare some chemical products, such as furan acrylic acid and chloroacetic acid. Sodium acetate trihydrate ...

AI Technical Summary

Problems solved by technology

One of the biggest problems with this method is that because sodium acetate will be supercooled during the crystallization process, it is difficult to crystallize larger particles, so it is necessary to use a large energy-consuming ice brine to keep the sodium acetate solution at a temperature of 5-10 ° C. under crystallization

The method does not relate to the process of drying sodium acetate hydrate to obtain anhydrous sodium acetate