Troubleshooting Ion Exchange Resin Performance in Corn Sweetener Refining

While most operational problems with ion exchange systems are the result of mechanical failure or improper conditions of the ion exchange equipment and support systems, there are a number of process problems that can be more difficult to diagnose and correct.

Below is a list of some common ion exchange process related problems, the bolded terms act as the conditions for diagnosing them and the text that follows is the possible causes for those problems. If you have more questions about a product-related issue, please don't hesitate to reach out to the Purolite team. 

1. Low Throughput
Low throughput is caused by any number of failures such as poor fluid distribution or collection, incomplete regeneration, low resin volumes, fouled resins, inaccurate volume totalization, or microbiological growth in a resin bed.

2. High Pressure Drop
High pressure drops are most commonly caused by resin fines not being backwashed out, plugged distributors or strainers, or high syrup viscosity due to a drop-in temperature or increase in dry solids concentration. They can also be caused by foreign particulates such as carbon, diatomaceous earth or microbiological growth plugging the bed or laterals.

3. Excessive Rinse
Organic fouling, as well as poor fluid distribution or collection can be caused by excessive rinse. In addition, high rinse or service temperature may cause thermal degradation.

4. Resin Breakup and Poor Rinse Water Quality
Excessive service pressure drops across resin bed, as well as osmotic shock from rapid volume change or electrolyte concentration change can cause either of these problems.

5. High Conductivity or pH in Service
These issues are typically caused by incomplete regeneration, bleed through from leaking service or chemical valve, poor fluid distribution or collection, resin fouling or degradation, excessive service flow rate or inappropriate mixing of cation and anion resins.

6. Alkaline Degradation of Syrups on Weak Base Anion Resin
Alkaline degradation of syrup can occur as a result of contact with strong base anion groups on the weak base anion resin when regenerated with NaOH. Degradation can be avoided by rinsing regenerated weak base anion resin with dilute NaCl after the slow rinse step, regenerating with soda ash or liquid ammonia or by using a weak base anion resin with no strong base groups.