How should organic amines be dechlorinated?
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I have been conducting experiments on removing chloride ions (from ammonium chloride) from amines over the past few months. The target is to keep the chloride level below 50 ppm, but I haven’t been able to achieve this yet. I hope those with more experience can offer some advice! ! ! The crude amine contains approximately 10,000 ppm of chloride ions. Amines are slightly soluble in water (0.3% at room temperature). I have tried recrystallizing the crude amine using deionized water followed by washing, but this method only removes the chlorine from the surface; some of the chlorine may remain trapped within the crystals after recrystallization and cannot be removed. I would like to ask what methods can effectively remove chlorides (ammonium chloride) with a relatively low amount of water used. . .
You can choose to use a metal salt, so that the metal ions in the salt form a precipitate with chloride ions, while the metal ions do not form complexes with ammonium ions! I forgot the specific substance; you can check the solubility table :)
1. Silver nitrate to remove chloride ions. 2. Use an organic solvent to extract and purify the amine.
Agree with the person above; considering that the CL content is 1%, chemical precipitation for chlorine removal may be costly if large quantities are involved, so extraction crystallization could be given priority
Thank you to the people above; the extraction methods you mentioned cannot be used in my process, as this process has always used alcohol as a solvent, and I don’t want to introduce any new solvents. The most frustrating thing is that ammonium chloride still has a certain solubility in anhydrous alcohol. So I’m wondering if there are any substances that can form complexes with chlorine to remove it?
Try adding calcium hydroxide. Calcium chloride forms a complex with ethanol, which can be removed by filtration.