Tulsion® Ion Exchange Resins for Water Demineralization

Demineralized water (DI water) plays a critical part in manufacturing various consumer and industrial products. Demineralized or deionized water is produced through demineralization, the process of removing total dissolved solids (TDS) and mineral impurities from the water feed to meet the required specification of certain applications.

Ion exchange resins are one of the top technologies for producing high-purity water free from ionic contaminants. Cation exchange resins are widely used in water softening for their ability to remove water hardness (calcium and magnesium ions) from the feed water and exchange them with sodium ions (Na).

Both anion and cation resins are used in industrial water treatment demineralization systems to produce demineralized water. The most common types of deionization systems are the two-bed deionization system, using cation and anion resins in separate units, and the mixed-bed demineralization system, combining both types of resins in one unit.

Ion exchange resins are also commonly used in the post-treatment polishing of other types of water treatment filtration systems, such as reverse osmosis (RO), ultra filtration (UF), nano filtration (NF), and electrodeionization systems (EDI). Their role in such systems is to remove any remaining impurities or contaminants and ensure the consistency of the water-purity levels.

Demineralization Systems

Demineralization plants must be designed and configured accurately to ensure the optimal efficiency of the plant and that the outlet water quality meets the required water specification. The inlet water quality and capacity requirements are also important in the plant design. Here is a typical scheme for producing distilled water quality:

Pre-filtration → SAC → DEG → SBA → MB

Abbreviations:
SAC: Strong Acid Cation	SBA: Strong Base Anion	WAC: Weak Acid Cation	WBA: Weak Base Anion
MB: Mixed Bed	DEG: Degasser	ppm: Parts per million = mg/l (milligrams/lit)

SAC: It removes all cations and regenerates with 5% HCl or 1.5% to 5% H₂SO₄

Reaction:
(Ca) HCO₃		(Ca)		(HCO₃)
(Mg) Cl	+ R – H →	(Mg) R	+	H (Cl)
(Na) SO₄		(Na)		(SO₄)

Degasser:

H₂CO₃ + Air -> H₂O + CO₂↑

SAC Outlet Quality:
pH = 2.5 to 3.8

Sodium= < 1 ppm

DEG Outlet Quality:

CO₂ = < 10 ppm as CaCO₃

SBA: It removes all anions and regenerates with 4%–5% NaOH.

Depending on the application and desired water quality, demineralization plants can have different designs and configurations for the ion exchange process. Here are some examples depending on the output quality required:

Reaction:
(HCO₃)		(HCO₃)
H (Cl)	+ R – OH →	R - (Cl)	+	H₂O
(SO₄)		(SO₄)

SBA Outlet Quality:
pH = 7.5 to 8
Silica= <0.2 ppm
Conductivity= < 5 μs/cm

MB Outlet Quality:
pH= 6.5 to 7
Silica= <0.02 ppm
Conductivity= <0.2 μs/cm

MB: It is used for final polishing. It consists of a stoichiometric mixture of highly regenerated SAC in hydrogen and SBA in hydroxide, respectively.

System	Application	Typical Output Quality (Conductivity in μmho, Silica in ppm)	Advantages & Limitations
SA→WB	Silica and CO₂ are not objectionable	Cond. 10–40 Silica: Unchanged	Low equipment cost, low regenerant cost
SA→SB	Lower-alkalinity raw water, CO₂ and silica removal required	Cond. <15 Silica: 0.02–0.10	Low equipment cost, medium regenerant cost
SA→D→SB	High-alkalinity raw water, CO₂ and silica removal required	Cond. <15 Silica: 0.02–0.10	Low regenerant cost, repumping required
SA→D→WB→SB	High-alkalinity raw water; Cl and SO; silica and CO₂ removal required	Cond. <15 Silica: 0.02–0.10	Highest equipment cost, lowest regenerant cost, repumping required
WA→SA→D→WB→SB	High-hardness, alkalinity; Cl and SO, RW; silica and CO₂ removal required	Cond. <15 Silica: 0.02–0.10	Higher equipment cost, lowest regenerant cost, repumping required
CF→D→SB	High-sodium RW, low leakage required	Cond. <10 Silica: 0.02–0.05	Medium equipment cost, lowest acid costs for leakage obtained
SA→SB→SA	High-sodium RW, existing two-bed system, low leakage required	Cond. <10 Silica: 0.02–0.05	Easy to retrofit, danger of acidic water on anion breakthrough
MB	Low-solids RW, high purity required	Cond. <5 Silica: 0.02–0.10	Low equipment cost, high chemical cost, higher attention required
SA→SB→MB	High-solids RW, high purity required	Cond. <1 Silica: 0.01–0.05	Medium equipment cost, high chemical cost, higher attention required

Selecting Your Ion Exchange Resins

Selecting the right resin for your system can be challenging. Many criteria need to be considered, including input and output capacity, water feed impurities, required output quality, and regenerant types.

Our teams at ChemPoint and Thermax can help you identify the ideal ion exchange resin for your system. We offer an extensive portfolio of Tulsion® ion exchangers from Thermax specifically designed to meet the needs of your system and the quality required for your water treatment applications. Our ion exchange product range includes:

Anion Exchange Resins:

Product	Description	Features & Benefits
Tulsion® A-2X MP	A macroporous weak base anion exchange resin with tertiary amine functional groups	Excellent for high-TD water when Cl, SO₄, and NO₃ concentrations are higher than usual. It also offers osmotic stability and high regeneration efficiency.
Tulsion® A-23 P	A gel-type strong base anion type I exchange resin with quaternary ammonium functional groups	Excellent choice for high-silica raw water feed. It offers high stability and good exchange kinetics to meet low silica and other contaminants in the water output.
Tulsion® A-32	A gel-type strong base anion type II exchange resin with quaternary ammonium functional groups	Offers optimal output, higher regeneration efficiency, and lower operational cost.
Tulsion® A-27 MP	A macroporous strong base anion type I exchange resin with quaternary ammonium functional groups	A perfect choice for treating water containing high levels of dissolved organics and higher silica levels.

Cation Exchange Resins:

Product	Description	Features & Benefits
Tulsion® T-42 H	8% cross-linked, gold-colored resin in hydrogen form	A cost-effective resin with good exchange kinetics for use in clean nonchlorinated water demineralization or softening.
Tulsion® T-52 H	10% cross-linked, gold-colored resin in hydrogen form	Excellent choice for chlorinated raw water feeds and offers high physical and chemical stability.
Tulsion® T-42 H BC	8% cross-linked, black-colored resin in hydrogen form	Similar to T-42H, a cost-effective option but supplied in a black form and offers higher stability and exchange kinetics.

Mixed-Bed Exchange Resins:

Product	Description	Features & Benefits
Tulsion® MB-108 BG	A mixture of black-colored SAC resin in H form and SBA Type I resin in OH form in a 1:1 ratio	Excellent choice for DI water systems to provide water output with resistivity in the range of 16 to 17.5 mho.
Tulsion® MB-115 BG	A mixture of black-colored SAC resin in H form and SBA Type I resin in OH form in a 1:1.5 ratio	Excellent choice for DI water systems to provide water output with resistivity 17.5 mho or above.
Tulsion® CAM-401	A mixture of SAC resin in H form and SBA Type I resin in OH form in a 1:1 ratio	Suitable for high-volume DI systems in commercial and service applications, such as window cleaning and car washes.
Tulsion® MB-101 CC	A mixture of SAC resin in H form and SBA Type I resin in OH form in a 1:1 ratio with a color change indicator (blue→amber)	Commonly used in lab applications and a perfect choice for systems when color change upon exhaustion is required.