Method for separating p-hydroxyphenylglycine and ammonium sulfate from glycine mother solution

Abstract

The invention discloses a method for separating p-hydroxyphenylglycine and ammonium sulfate from a glycine mother solution, which is characterized by comprising the following steps: regulating the pH value of a glycine mother solution containing p-hydroxyphenylglycine and ammonium sulfate to 3.0-8.0, sending into a continuous chromatographic separation system filled with a strong acid cation exchange resin at 10-80 DEG C, eluting by using water as an eluting agent, and respectively collecting an eluate and a residue solution to obtain the two products p-hydroxyphenylglycine and ammonium sulfate, thereby implementing efficient separation of the p-hydroxyphenylglycine and ammonium sulfate. The method has the advantages of compact equipment, simplified system, reduced pipelines and smaller occupied area; the method is continuously operated under continuous operation, the composition and concentration of the product are basically kept stable; the method has favorable operating flexibility, and can automatically regulate the rotation speed according to the variance in production load; the method lowers the operating cost and equipment investment; and the separating effect is good, and the purity of the separated p-hydroxyphenylglycine is high.

Description

technical field [0001] The invention relates to a technology for separating and purifying p-hydroxyphenylglycine from p-hydroxyphenylglycine mother liquor, in particular to a method for separating p-hydroxyphenylglycine and ammonium sulfate from glycine mother liquor by using chromatographic technology, which belongs to the field of chemical separation. Background technique [0002] The synthesis mother liquor of p-hydroxyphenylglycine contains a large amount of phenol and ammonium sulfate and other substances, and direct discharge will lead to high COD content in wastewater, causing environmental pollution; in addition, because the mother liquor contains p-hydroxyphenylglycine, etc., if it is discharged outside, it will cause waste . In the prior art, distillation is often used in the treatment of p-hydroxyphenylglycine synthesis mother liquor, the quality of the extracted product is poor, and the phenol in the waste water is easy to exceed the standard, causing serious env...

AI Technical Summary

Problems solved by technology

[0002] The synthesis mother liquor of p-hydroxyphenylglycine contains a large amount of phenol and ammonium sulfate and other substances, and direct discharge will lead to high COD content in wastewater, causing environmental pollution; in addition, because the mother liquor contains p-hydroxyphenylglycine, etc., if it is discharged outside, it will cause waste

In the prior art, the treatment of p-hydroxyphenylglycine synthesis mother liquor is mostly purified by distillation, the quality of the extracted product is poor, and the phenol in the waste water is easy to exceed the standard, and the environmental pollution is relatively large

CN102060311A discloses a method of concentrating glycine mother liquor at atmospheric pressure and then using methanol to separate ammonium sulfate and p-hydroxyphenylglycine. This method requires the use of methanol, which is dangerous to humans, and is prone to produce organic solvent residues and introduce new impurities ; CN101967106A discloses a method for treating L-p-hydroxyphenylglycine desalination mother liquor by using bipolar membrane electrodialysis technology combined with alkali adjustment or ion exchange resin activation process. There are certain safety hazards in the application of medicine, coupled with the increase in energy consumption, it has not been able to truly achieve low-carbon environmental protection

CN101759583A discloses a new technology for recycling DL-p-hydroxyphenylglycine waste, which is to add water, recycled materials, hydrochloric acid, and activated carbon in a certain proportion, add activated carbon to decolorize and filter after heating and dissolving, and adjust the pH value of the filtered mother liquor to a certain level with ammonia water. range, centrifugation to obtain qualified p-hydroxyphenylglycine, this method also has the problems of cumbersome operation and high energy consumption

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