AbstractFire Resistant Fluid (FRF), used in turbine governing systems, transforms during operation, forming substituted phenol and phosphoric acid. The use of strong Base Anion Resin (SBA resin) to reduce the Total Acid Number (TAN) of FRF is widespread. However, the regeneration of these oil‐fouled resins is crucial due to their high cost and the challenges associated with their environmental disposal. In this study, we present a novel method for recovering exhausted resin by treating it with an aqueous solution of citric acid, followed by regeneration with a caustic soda solution. We optimized the recovery percentage in the ion exchange capacity by testing varying concentrations of the citric acid solution under different reaction conditions. The highest recovery of ion exchange capacity achieved was 55 % after soaking for 16 hours in a 5 % citric acid solution, followed by regeneration with a 5 % NaOH solution. The efficacy of citric acid in this research was further explored through a Density Functional Theory (DFT) study. This study is significant as it is the first to demonstrate the successful regeneration of oil‐fouled resins with high ion exchange capacity using citric acid, a more environmentally friendly and cost‐effective alternative.
Read full abstract