You can use acid treatment, such as Hydrochloric acid, sulfuric acid or phosphoric acid. These would produce salt in crude glycerin... the separation method of these salts can be done either through crystalization or precipitation ...
Please refer to the following link,
Article Characterization of Crude and Purified Glycerol from Biodies...
Thank you so much for your answer. I tried to Hydrochloric acid treatment but the amount of salt didn't change. Can I do something else or I try it whit sulfuric acid or phosphoric acid too ?
acid treatment, such as Hydrochloric acid, sulfuric acid. These would produce salt in crude glycerin... the separation method of these salts can be done either through crystalization or precipitation