Crude glycerin is further processed in a distillation unit for obtaining distilled and refined glycerin. During this process residual organic matter, water, salt, methanol, and odors are removed. The glycerine distillation plant is broadly divided into three main sections: the de-aeration, distillation and bleaching section:
- The de-aeration loop consists of a re-circulation pump and heat exchanger. The pump circulates the crude glycerine to the de-aeration vessel and feeds de-aerated crude glycerine to the distillation column;
- The distillation section is composed of various systems consisting of a vaporization system, stripping system, rectification system, pump around system and a scrubbing system;
- The bleaching section used activated carbon in order to remove colour and odour in the final stage of the purification. Distilled glycerine is cooled to bleaching temperature and then passed through the bleachers. The bleached glycerine is filtered and then finally cooled down to storage temperature.
Thanks to the activated carbon being used in the final purification process, a pure and odourless type of glycerin is distilled, ready for technical or even pharmaceutical applications:
- Technical grade glycerin is a refined, high-purity product that is water white with most of its contaminants completely removed. Technical grade glycerin contains no methanol, soaps, salts, and other foreign matter.
- Pharmaceutical grade glycerine, as per European Pharmacopeia, is a pharmaceutical grade glycerin suitable for food, personal care, cosmetics, pharmaceuticals, and other specialty applications.