Troubleshooting a resin clumping issue in a power generation condensate mixed bed
A large power generation company in Australia operates several coal power stations. Plant systems include make-up demineralizers, followed by mixed beds as well as condensate mixed bed units. Purolite historically supplied the utility’s make-up demineralizer resins, but not their condensate mixed beds.
After many years in service, the condensate mixed beds were due for a rebed.
Satisfied with Purolite products and our reputation in the industry, the power station contacted Purolite and purchased Purolite Supergel™ SGC650H and Supergel™ SGA550MB resins to replace the condensate mixed red resins that reached the end of their useful life. The customer stated that they were comfortable commissioning the resin.
In reality, however, specific knowledge on how to commission the new mixed bed resins was patchy and incomplete due to the age of the existing mixed-bed resins. Some assumptions were made on the accuracy on the commissioning procedures, and the plant was commissioned. Problems occurred quickly.
Understandably, the Chemical Shift Team Leader was upset. He called Purolite noting that the new resins did not work properly, that they never experienced problems with their previous resin and followed the same procedures as they in the past. They were not satisfied that problems were introduced into their system.
After some investigative questioning from the Purolite technical expert, it was preliminarily determined that the problem experienced was clumping, also called resin agglomeration, where the resin sticks together. Because of the resin stickiness, they were unable to commission and bring the condensate polishing system back online—putting the duration of their scheduled outage in jeopardy.
Clumping issues are not uncommon when commissioning new mixed beds, and the likelihood of occurrence increases greatly when commissioning procedures specified by the equipment OEM are not followed.
Instead of making further assumptions, however, Purolite collected resin samples and rushed them to our Technical Services Laboratory. The laboratory team was able to replicate and confirm the problem. Purolite’s team also did additional studies to assess how to best unclump the resin using readily available chemicals and equipment that the client would have on site—and that would be safe to use for their condensate polishing system.
It was important to not compromise the resin quality during the correction process as doing so would cause ongoing and long-term performance limitations.
Testing showed that a combination of brine and a proprietary surfactant was effective at unclumping the resin without causing damage to the beads.
The lab supplied seven liters of the surfactant to the customer free of charge, along with MSDS paperwork that was critical to permit usage of the chemical within a power station. Additionally, a workable fix procedure was clearly defined so that the client could resolve the problem on site.
Purolite also met with plant staff to review the reverse clumping procedure as well as proper commissioning steps—noting the importance of following the steps precisely. Purolite also provided refresher training to the operators for overall best practices for their system and processes.
The client was able to resolve the issue, and returned the system to service. The plant employees were very happy with the level of attention that they received—and the level of system training they received. As a result, they subsequently placed an order for make-up demineralizers at the same plant, as well as orders for a second power station.
Because of the expedient nature of the troubleshooting, it was not necessary for high-level plant management to get involved. The rebed was successfully completed and bought back on line within the planned outage schedule for unit, such that the baseload capacity was back in time for peak demand summer season.
It is understandable to think that resins can simply get swapped out, and that processes would not be affected. However, resins have specific characteristics and properties and any change out—even if done with the same exact resin—can require processes to be tweaked. If a different resin is used, a system and process review is particularly important.
Type of resin, age of equipment, changes in water, flow rate, and a host of other factors play into the commissioning procedure and should be discussed with the manufacturer to ensure that the plant goes back online smoothly. It’s also a good idea to let the sales team know when the commissioning will occur—so that they can be available for remote consulting, or even be on site.
Purolite has a well-earned reputation for having a technical sales team that is always available, highly knowledgeable and willing to go the extra step for customers.