A kind of energy-saving clean production method of iminodiacetic acid

Abstract

The invention discloses an energy-saving and clean production method of iminodiacetic acid, which comprises the following steps: 1) using iminodiacetic acid di-salt solution as raw material, entering a bipolar membrane electrodialysis system for bipolar membrane electrodialysis treatment, salt chamber Control pH=3.0~4.0 to obtain a mixed solution of iminodiacetic acid monosalt and iminodiacetic acid, and alkali chamber to obtain an alkaline solution; 2) Mix the iminodiacetic acid monosalt and iminodiacetic acid obtained in step 1) Adding acid to acidify to pH=2.0~2.5; 3) Separating and purifying the mixed solution of iminodiacetic acid and inorganic salt obtained in step 2) to obtain iminodiacetic acid and inorganic salt respectively. The method of the invention does not need to be diluted, can reduce the amount of inorganic salt produced by about 70%, and also greatly reduces power consumption, and can achieve the best economic benefits. In addition, the present invention directly uses the iminodiacetonitrile reaction liquid as the starting material, avoiding the cumbersome purification process of the iminodiacetonitrile.

Description

technical field [0001] The invention relates to a production method of an organic acid, in particular to an energy-saving and clean production method of iminodiacetic acid. Background technique [0002] Iminodiacetic acid, CAS No. 142-73-4, abbreviated as IDA, is an important chemical intermediate, widely used in pesticides, medicines, rubber, heavy metal complexing agents, etc., mainly used for the synthesis of glyphosate (glyphosate), etc. Pesticide intermediates, but also used in complexing agents, cleaning agents, stabilizers and surfactants. [0003] The industrial production routes of iminodiacetic acid include iminodiacetonitrile hydrolysis method and diethanolamine dehydrogenation method. Since domestic diethanolamine relies on imports, the price fluctuates greatly, so iminodiacetic acid is produced from iminodiacetonitrile to produce glyphosate Has become the domestic mainstream route. But, existing iminodiacetic acid industrial production method has following two...

AI Technical Summary

Problems solved by technology

However, since the solubility of iminodiacetic acid in water is only about 3 grams, it is necessary to dilute the disodium salt of iminodiacetic acid in large quantities, resulting in a decrease in the membrane throughput of bipolar membrane electrodialysis and an increase in the demand for the membrane. Increase investment, and the purification of iminodiacetic acid in the later stage needs to distill a lot of water

Furthermore, when bipolar membrane electrodialysis is carried out to iminodiacetic acid disodium salt, the conversion time in the early stage is shorter and the power consumption is lower, and the conversion time in the later stage is longer and the power consumption is higher. Although the direct conversion to iminodiacetic acid is a clean production process, the energy consumption of the whole process is high, so the industrialization of this method is difficult to implement

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