How does ion exchange resin work?

 

Ion Exchange Resins Market

To completely comprehend how IX resins function, it is necessary to first comprehend the ion exchange reaction's principles. Simply put, ion exchange is the reversible exchange of charged particles (ions) with other ions of the same charge. This happens when ions atop an insoluble IX resin matrix essentially swap places with ions of the same charge in the surrounding solution.

According to Coherent Market Insights the global ion exchange resins market is projected to surpass US$ 1900 million by the end of 2027, in terms of revenue, growing at CAGR of 5.4% during the forecast period (2020 to 2027).

Because of its functional groups, which are essentially fixed ions that are permanently attached inside the polymer matrix of the resin, the IX resin works in this fashion. These charged ions will quickly connect with ions of the opposite charge, which will be delivered via a counterion solution. Until equilibrium is attained, these counterions will continue to connect with the functional groups.

The solution to be treated would be added to the IX resin bed and allowed to run through the beads during an IX cycle. The functional groups of the IX resin attract any counterions present in the solution as the solution passes through it. If the functional groups have a stronger affinity for the new counterions than the ones already present, the ions in solution will displace the existing ions and connect with the functional groups via shared electrostatic attraction. In general, the larger and/or valency of an ion, the stronger its affinity for ions of the opposite charge.

Let's put these ideas into practise with an IX water softening system. The softening mechanism in this case is a cation exchange resin with sulphonate anion (SO3–) functional groups attached to the matrix of the IX resin. The resin is subsequently treated with a counterion solution comprising sodium cations (Na+). Electrostatic attraction holds the Na+ ions to the fixed SO3– anions, resulting in a net neutral charge in the resin. A stream of hardness ions (Ca2+ or Mg2+) is introduced to the cation exchange resin during an active IX cycle. The hardness cations displace the Na+ ions, which subsequently flow out of the IX unit as part of the treated stream, because the SO3– functional groups have a stronger attraction for them than for the Na+ ions. The IX resin, on the other hand, retains the hardness ions (Ca2+ or Mg2+).