Ion Exchange Resin Definition(Feat. Samyang)

Hi nice to meet you

I'm K in H&K Environment

Many water specialists in industries would try to remove ion dissolved in wastewater or raw water to reuse or use as process water.

For today, I'm going to talk about Ion Exchange Resin

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All materials in this page from Samyang (Korean Company)

In Korea, this company first developed Ion Exchage Resins 

(Clik Logo) - able to change Korean to English in hompage 

Samyang link

 

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1. Impurities in Raw water and treatment method for that

 - Ca2+, Mg2+: The cause of Scale

 - Na+, K+: The cause of Carry over (The phenomenon Solids and Liquid water are evaporated together)

 - HCO3-: The cause of Line Corrosion and Bubble

 - SO42-, NO3-, Cl-: The cause of Line Corrosion and Scale

 - SiO2: The cause of Scale

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2. Definition of Ion Exchange Resin

- Resin having Functional Group

* Functional Group: It is related to determine the property of chemicals

- Ability for dividing ion from water by ion exchanging 

- Use for removal of impurities and separation of ionic substances

- Mostly use for a pure water manufacturing process

- Not only having exchanger outside, but also retaining more inside

ion exchagne resin

 

3. The principal of maufacturing

- It could be made by adding exchanger like SO3-, NH3+ to polymer three-dimensional crosslinked

- Copolymer with Styrene Monomer and DVB(Divinyl Benzene) monomer

* Copolymer: A polymer composed of two or more different monomers. Polymer materials with various physical properties are obtained by using monomers with different physical properties

- When add Functional Group to polymer, volume is increased (0.2~0.3→0.5~0.6mm)
- General SIZE: 0.3~1.2mm

Ion exchange resin manufacturing

 

4. The mechanism of ion exchange reaction

1) Strongly Acidic Cation exchange ion resin

- R-SO3H + Na+ ↔ R-SO3Na + H+ (SERVICE)

- Since it is a reversible reaction, the reaction takes place from the side with the higher concentration to the opposite side.

- Reusable through regeneration process after removing Na+ ions, which are target ions
  (R-SO3Na + H+ ↔ R-SO3H + Na+ (REGENERATION)

* Not only removing Na+, but also other cation ionic materials

Cation exchange ion resin mecahnism (strongly acidic)

2) Strongly Basic Anion exchange resin

- R-NHOH+ Cl- ↔ R-NHCl+ OH- (SERVICE)

- Since it is a reversible reaction, the reaction takes place from the side with the higher concentration to the opposite side.
- Reusable through regeneration process after removing Cl- ions, which are target ions
  (R-NHCl+ OH- ↔ R-NHOH+ Cl- (REGENERATION)

* Not only removing Cl-, but also other anion ionic materials

Basic exchange ion resin mecahnism (strongly basic)

3) Ion exchange resin reaction/regeneration(after reaction) mechanism (cation/anion exchange resin in mixed tower)

- Service Flow: Removal of Strong mineral acids like SO42-, Cl-, NO3- etc

  -> Removal of HCO3-, HSiO3- and little Cl-

- Regeneration Flow: The regeneration efficiency of TRILITE AW80LB is so high that possible to regenerate with regenerated waste fluid passing TRILITE KA18LB

  -> Regeneration by desorption of HCO3-, HSiO3-, Cl- adsorbed

 

5. Criteria for classification of ion exchange resin

1) Particle size

2) Particle distribution (uniform or non-uniform)

- The more uniform, the more reacts uniformly

- High productivity due to high operation exchange capacity even at high flow rate

- Less differential pressure rise and channeling even after prolonged use

- Physically and chemically stable, so stable performance and long life time

3) Degree of crosslinkage (DVB%, Divinyl Benzene%)

- The degree of crosslinkage varies according to the ratio of DVB to Styrene

- When DVB is increased, it becomes a denser network shape

- 8% is standard (criteria of low/high crosslinkage classification)

4) Porous (Gel type, Porous type [reinforced])

5) Exchanger (strongly acidic/weakly acidic, strongly basic/weakly basic resint)

■ Cation exchange resin (strongly acidic/weakly acidic)

① Strongly acidic: Sulfuric acid is used as an exchanger, and cation can be exchanged over the entire pH range (most widely used)

② Weakly acidic: A carboxyl group(-COOH) is used as an exchanger, and there is no exchange capacity in acidity. Used at pH 5-14, easy to regenerate. Disadvantage is that it is easy to miss the exchanged ions.

■ Anion exchange resin (strongly basic/weakly basic)

① Strongly basic: TMA(Trimethylamine) and DMEA(Dimethylethanolmine) are used as exchangers. Used at the entire pH range.

② Weakly basic: Tertiary amine is used as an exchanger, and there is no exchange capacity in basic solution. Used at pH 1-9, easy to regenerate, easy to miss exchanged ions.

■ Chelating Resin

Because it has a functional group that can form chelates with metal ions, it has high selectivity to metal ions than general ion exchange resin.

6) Various post-processing

 

6. The property of ion exchange resin 

1) Exchange Capacity

- Measurement of ion exchange capacity

- Equivalent per unit volume: eq/l-wet resin

- Equivalent per unit weight: eq/g-dry resin

2) Moisture Retention

- An appropriate level of moisture is required to maintain the performance of the ion exchange resin.

- Avoid contact with oxidizing substances as far as possible

- When the degree of crosslinkage is high, moisture decreases

3) Specific Gravity and Apparent Density

- Standard for product packaging

- If the degree of crosslinkage is high, true specific gravity and apparent specific gravity increase

4) Particle size and Uniformity coefficient

The bigger particle size is, the better flowage, the worse physical intensity (reaction rate is almost same) 

5) Swelling rate

- Volume of ion exchange resin

- The higher the degree of crosslinkage, the lower swelling rate.

6) Operating Temperature

- Cation exchange resin: stable up to 120℃

- Anion exchange resin: stable up to 40~80℃

7) Selectivity

- There is selectivity depending on ion, so it is possible to select an appropriate ion exchange resin

- Strongly acidic cation exchange resin: Li+<Na+<Rb+<Cs+; Mg2+<Ca2+<Sr2+<Ba2+

- Anion exchange resin: Citrate>SO42->Oxalate>I->NO3->CrO42->Br->SCN->Cl->Formate>Acetate>F

8) Reaction Rate

- The smaller the particle size, the faster the reaction rate.

- The lower the degree of crosslinkage, the faster the reaction rate.

9) Efficiency of Regeneration

- Cation exchange resin regenerated material: HCl, H2SO4

- Anion exchange resin regenerated material: NaOH

- Since the ion exchange resin follows reversible reaction, the higher the regeneration level, the lower the theoretically expected regeneration efficiency.

 

7. Types of ion exchange resin towers

Classfication of ion exchange resin bed

Calssification of service and regeneration direction, Classification of ion exchange resin tower structure

 

8. Ion exchange resin tower combination

Have a nice day

 

Samyang link