The inert resin has no ion exchange effect and is mainly used to separate the anion and cation resins in the mixed bed to avoid cross-contamination between the resins, that is, when the mixed bed is regenerated, the cation or anion resin is respectively contaminated by NaOH or H2SO4 (HCl). When filling the resin, it is difficult to accurately calculate the transformation expansion rate of the resin. The male resin cannot happen to be at the center line of the middle row of pipes, and the same is true for the female resin, which cannot be just right. Therefore, the added inert resin is between the positive and negative resins to separate the negative and positive resins, which is very beneficial to the backwashing and stratification and the regeneration of the positive and negative resins. Otherwise, the resin will be cross-contaminated, which will delay the ion release rate and affect the exchange results.
Amino acids are widely used in the food and agricultural industries as nutritional supplements and chelating agents, and are also important components in the production of pharmaceuticals, biodegradable plastics and chiral catalysts. Most amino acids can be produced by industrial-scale fermentation, while the conventional downstream separation and purification processes are quite complex. Electrodialysis (ED) is considered a promising technique for the separation and purification of amino acids. Due to the weak dissociation ability of organic ions and the complex chemical structure, the migration of organic ions in the ED process is not satisfactory. Adding inert resin to the compartment of the electrodialyzer can improve the process performance. The inert resin can act as a turbulence promoter, improve current efficiency and promote the transport of glutamic acid and lysine. The filling percentage of the inert resin in the dilution compartment promotes ED performance in order: 25% (50%)> 100%> 0%.( Fangfang Yuan, et al., 2015)
Inert resins can also be used in a three-layer fixed mixed bed. The inert resin does not participate in the ion exchange reaction during the regeneration process and the operation process, and only plays the role of separating the cation and anion resins during the regeneration process, avoiding the cross-contamination of the strong acid and strong alkali resin during the regeneration process, and improving the exchange capacity and water quality quality.( Haifeng Ma., 2020)
- Mixed bed (two floors, three floors)
- Water treatment system
- Fangfang Yuan, et al. Influence of different resins on the amino acid recovery by resin-filling electrodialysis[J]. Separation & Purification Technology, 2015.
- Haifeng Ma. Process measures and disposal of three-layer mixed bed resin loading. Refining And Chemical Industry, 2020.