Requirements for the purity of brine in ion-exchange membrane caustic soda production
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I just read the Q&A guide on the operation of ion-exchange membrane caustic soda, edited by Xing Jiawu and Liu Dongsheng. Among them is a description of the requirements for the purity of saltwater. The purification process is primarily aimed at dealing with the impurities found in sea salt, such as calcium and magnesium ions, sulfate ions, algae, humic acid, and others. For brine from other sources, it seems there are no methods for removing impurities. Now we plan to use the saline wastewater from the production process as the brine feedstock for ion-exchange membrane caustic soda. In addition to a large amount of sodium chloride in water, there are also a few percent of glycine, ammonium chloride, small amounts of chloroacetic acid, diethylenediamine acetate, and other impurities. Will these impurities affect the electrolyte membrane? Is it necessary to get rid of it? ?
Different ion membrane components have varying requirements regarding operation and the quality of saltwater, and the requirements of different patent holders may differ as well. These parameters are specified in the operating procedures and process packages. Of course, in theory, aside from sodium chloride, the lower the content of other impurity ions, the better.
Same question – our company is also moving in this direction! It’s just that the components are different...
What components do you have? You might as well list them out; there are many talented people out there, and maybe someone among them can help you solve the problem: lol
Our composition is relatively complex; aside from salts, organic substances make up the largest portion, with tar being the main component； Other organic compounds include trace amounts of toluene...
The components of polymers must be removed, as they have a significant impact on the membrane. It’s less clear regarding small organic molecules.
Whether it is brine or ion-exchange membranes, membrane manufacturers have high requirements regarding organic substances, and ammonium chloride is also subject to restrictions; it is recommended to remove such substances completely before reusing the membranes to avoid unnecessary significant losses
It seems to be intended only for macromolecular organic substances, to prevent membrane clogging. I’m not too sure about small molecules. It’s possible to use small-scale equipment for simulation first to see the specific impact