Natural water supplies contain dissolved salts, which dissociate in water to form charged particles called ions. These ions are usually present in relatively low concentrations. The presence of some of these ions lead to problems for applications such as in heating systems, steam generation etc. and hence are termed as ionic impurities. The commonly encountered ions in water include the positively charged cations, namely Calcium, Magnesium and Sodium. The negatively charged anions include the alkalinity, sulfates, chlorides and Silica, Nitrates, etc.
Ion Exchange resins are well suited for removal of these impurities for the following reasons:
• Resins have a very high capacity to remove ions in low concentrations.
• Resins are most stable and readily regenerated.
• Resins are stable over a wide range of commonly applicable temperatures.
• The process is suitable for both large and small installations.
• The process is reversible & hence sustainable for longer durations.
Ion Exchange Resins are generally insoluble polymeric materials manufactured using suspension polymerization with Styrene and Di Vinyl Benzene (DVB) or Acrylics & carry ion exchangeable functional groups.
These ions can be exchanged with stoichiometric equivalent amount of ions of the same charge. Carrier's of exchangeable cations are called Cation exchangers and that for anions are called Anion exchangers.
Use of right quality ion exchange resins designed using maximum possible available data and optimised regenerate usage ensures Saving on cost of chemicals used, preserve natural resources and reduce carbon footprints for sustainable future.
Strong Acid Cation Exchange Resins - Also known as SAC resins
• Crosslinked Poly styrene beads with Sulfonic acid (-SO3H) as functional group.
• Can exchange all the cations from water; Strong (Calcium, Magnesium, K, etc) as well as weak cations (bicarbonates, etc).
• Total exchange capacity varies depending upon the degree of crosslinking.
• These resins are available in either Sodium form or hydrogen form.
• The Sodium form resins used in water softening are regenerated using Sodium Chloride or NaHCO3.
• Hydrogen form resins used in demineralization cycle are regenerated using HCl or H2SO4.
• Strong Acid cation resins have either Gel or Macroporous structure depending upon the size of the pores. Gel type resins are transparent beads while Macroporous beads are opaque.
Weak Acid Cation Exchange Resins - Also known as WAC resins
• Acrylic Base resins with carboxylic acid group (-COOH) as functional group.
• Regeneration very efficient, almost stoichiometric.
• These resins can be used effectively in conjunction with SAC.
• Total Exchange capacity varies depending upon the degree of crosslinking.
• These resins come either in Gel Type or Macroporous type.
• These resins are available in either Sodium form or hydrogen form.
• Can remove hardness associated with alkalinity only. (Eg. WAC in H form can remove Na ions associated with bicarbonate ions but not with CI ions from a solution that contains both NaCL as well as NaHCO3.
• The high regeneration efficiency of these resins is effectively used when the inlet alkalinity is high. Further this resin get regenerated at low acid concentrations, thus helping optimization of regenerant usage. Generally when used in demineralization cycle, WAC is regenerated using the waste regenerant from SAC with a thoroughfare process.
Strong Base Anion Exchange Resins - Also known as SBA resins
• Strong Base anion exchange resins either have a Crosslinked Styrene divinyl benzene structure or Acrylic structure.
• These resins come either have a Gel structure or a Macroporous structure and generally supplied in Chloride form.
• These resins are regenerated using caustic Soda (NaOH) using either co-current or Counter current regeneration modes.
• Strong Base anion resins removes all Anions from water and are categorized as Type I or Type II depending on the nature of the functional groups / type of amine used during the chemical activation process.
Type I
• Quaternary Ammonium Functional Group. Chemically it has three methyl groups.
• Functional group with the highest basicity amongst commonly used anion resins.
• Used when very low silica levels are desired (< 0.2 mg/l).
• Requires excess of regenerant than SBA Type-II resin.
Type II
• Quaternary Ammonium Functional Group. Chemically one of the methyl groups of type-I is replaced with ethanol group.
• Less Basic Functional Group as compared to SBA Type-I.
• Higher Silica Leakage Compared to Type I (< 0.5 mg/l ) and offers higher operating capacity.
• Easier to Regenerate.
Weak Base Anion Exchange Resins - Also known as WBA resins
• Weak Base anion exchange resins have a tertiary amine functional group and has much lower basicity as compared to SBA resins.
• These resins come either have a Gel structure or a Macroporous structure and generally supplied in Free base (OH) form.
• WBA resin can remove anions associated with FMA (Cl-, SO4--) and cannot remove weak acids such as Silicic acid or Carbonic acids.
• This resin has a very high regeneration efficiency and can be regenerated using low concentration of NaOH, thus facilitating improved utilization of waste regenerant from SBA using thoroughfare co-current or counter current regeneration modes.
• This resins unique features can be best used for water with high FMA content.
Mixed Bed Resins
• Mixed bed resins are as the name suggests a mixture of Cation and Anion exchange resins, mixed in desired ratio so as to achieve the best performance of lowest conductivity and highest output. Both resins are used in regenerated H & OH form.
• When these resins are mixed and use, the Bed acts as an infinite set of Ion exchange columns and ensure s the finest quality of water measured in terms of conductivity. Hence output quality which normal bed may not achieve is made possible by using this combination.
• Mixed beds are available as non-regenerable (0ne use) as well as regenerable forms.
• Indicator resins or Colour Changing mixed resins which distinctively change colour on exhaustions are also available for ease of identification of resins usage without use of other measurement devices. Presently available variants are: 1) Green to Violet, 2) Blue to Yellow or 3) Green to Orange
Condensate Polishing Resins
• Polishing of return Condensate from Boilers for ensuring best quality of feed water in Boilers is essential for the efficient operations of power plants. These impurities often at ppb levels create major problems in Boilers which may lead to tube failures.
• The rigorous operating conditions in terms of Higher temperatures and flows as compared to normal demineralisation, makes condensate polishing a critical operations and hence decides on the Quality of resins to be used. Higher temperature stability, oxidation stability and higher osmotic stability as well as higher operating capacity of resins becomes a necessity.
• Few of the design technologies used for condensate polishing include: 1) Deep Bed Design 2) Candle type used Powdex resin Coating on filters.
Every single Degree temperature saved on cooling & re-heating the large volume of condensate, results in huge savings in Carbon foot print and fuel costs. Thus higher temperature stability of resins is of paramount importance for sustainability.
Adsorbent Resins
• Polishing of return Condensate from Boilers for ensuring best quality of feed water in Boilers is essential for the efficient operations of power plants. These impurities often at ppb levels create major problems in Boilers which may lead to tube failures.
• The rigorous operating conditions in terms of Higher temperatures and flows as compared to normal demineralisation, makes condensate polishing a critical operations and hence decides on the Quality of resins to be used. Higher temperature stability, oxidation stability and higher osmotic stability as well as higher operating capacity of resins becomes a necessity.
• Few of the design technologies used for condensate polishing include: 1) Deep Bed Design 2) Candle type used Powdex resin Coating on filters.
Every single Degree temperature saved on cooling & re-heating the large volume of condensate, results in huge savings in Carbon foot print and fuel costs. Thus higher temperature stability of resins is of paramount importance for sustainability.
Polymer Beads
• Crosslinked Styrene copolymer beads find applications in Various fields such as Investment casting wax fillers, interleaving polymers, etc. These spherical bead shaped polymers with high temperature stability, low ash and volatile content when used in Investment casting waxes as fillers, eliminates "orange peel" effect on the castings and ensure perfect shape without any deformations.
• The free flowing fine mesh smooth spherical beads having high thermal stability and anti straining agents helps reduce glass corrosion and maintain the scratch free glass surface.
• Fine mesh copolymers having different crosslinking percentage are also used in Biotechnology applications.
Pharmaceutical Grade Resins
• Use of Ion exchange resins as drug carriers, taste masking agents, Sustain release agents, or vitamin stabilising agents is well known in Pharmaceutical industries.
• Taste masking of bitter drugs like can be achieved using high capacity ion exchange resins manufactured under strict FDA approved manufacturing plants.
• Ion Exchange is the first company in India to establish and promote use of ion exchange resins as Pharmaceutical Excipients. IEI are accredited with G.M.P Certificate by the Food & Drugs Control Administration (FDA), Gujarat for manufacturing bulk drugs. INDION pharmaceutical grade resins are manufactured in state-of-the-art ISO 9001 & 14001 certified facility and are widely used in India and other countries.
• Refer our detail cross reference guide for available product selection and application areas.
Disclaimer: Due care should be taken to ensure Public Health & Safety & due diligence from experts in the field, prior to the use of these Ion exchange resins for any Pharmaceutical applications. The user is advised to Check the suitability / viability of our products for their specific use, prior to its use. SGAQUA Services are only the distributors of these products and do not take any liability whatsoever on its use.
