Method for reclaiming methenamine and glycin in glycin mother liquid by using nano-filtering technique

Abstract

The invention belongs to the field of recycling resources in a glycin (amino acetic acid) production trade, and provides a method for separating and reclaiming methenamine and glycin in a glycin mother liquid by using a nano-filtering film. The molecular weight intercepted by the used nano-filtering film is 50-300 daltons; the operating pressure is 1.8-4.0MPa; the operating temperature is 20-50DEGC; and most of ammonium chloride in the glycin mother liquid enters a nano-filtering permeation liquid by penetrating through the nano-filtering film through the separation of the nano-filtering film, and the methenamine and most of the glycin are intercepted into an intercepting liquid. The methenamine and the glycin in the intercepting liquid are recycled.

Description

technical field [0001] The invention belongs to the field of resource recovery and utilization in the glycine (aminoacetic acid) production industry. technical background [0002] The domestic traditional glycine production process uses chloroacetic acid and liquid ammonia to carry out ammonolysis reaction in the presence of urotropine, and then separates glycine by alcohol analysis. In this production method, the urotropine used as a catalyst is discharged with waste water after the reaction (production of one ton of glycine consumes 160-200 kilograms of urotropine), which not only wastes valuable resources, but also pollutes the environment. While separating glycine by alcohol analysis, 10% to 15% of glycine flows out with the mixture of methanol and water, which also wastes valuable resources. [0003] Nanofiltration (NF) is a new type of membrane separation technology developed in the past 20 years. Nanofiltration membrane is a composite charged membrane with nanometer ...

AI Technical Summary

Problems solved by technology

In this production method, the urotropine used as a catalyst is discharged with waste water after the reaction (production of one ton of glycine consumes 160-200 kilograms of urotropine), which not only wastes valuable resources, but also pollutes the environment

While separating glycine by alcohol analysis, 10% - 15% of glycine flows out with the mixture of methanol and water, which also wastes precious resources