Pilot-Scale Hydraulic Testing of Resorcinol Formaldehyde Ion Exchange Resin

Abstract

Savannah River National Laboratory (SRNL) performed pilot-scale hydraulic/chemical testing of spherical resorcinol formaldehyde (RF) ion exchange (IX) resin for the River Protection Project-Hanford Tank Waste Treatment & Immobilization Plant (WTP) Project. The RF resin hydraulic cycle testing was conducted in two pilot-scale IX columns, 1/4 and 1/2 scale. A total of twenty-three hydraulic/chemical cycles were successfully completed on the spherical RF resin. Sixteen of these cycles were completed in the 24″ IX Column (1/2 scale column). Hydraulic testing showed that the permeability of the RF resin remained essentially constant, with no observed trend in the reduction of the permeability as the number of cycles increased. The permeability during the pilot-scale testing was 3 times better than the design requirements of the WTP full-scale IX system. The RF resin bed showed no tendency to form fissures or pack more densely as the number of cycles increased. Particle size measurements of the RF resin showed no indication of particle size change (for a given chemical) with cycles and essentially no fines formation. The permeability of the resin bed was uniform with respect to changes in bed depth. Upflow Regeneration and Simulant Introduction in the IX columns revealed another RF resin benefit; negligible radial pressures to the column walls from the swelling of resin beads. The hydraulic and chemical performance of the spherical RF resin during cycle testing was found to be superior to all other tested IX resins. The pilot-scale testing indicates that the RF resin is durable and should hold up to many hydraulic cycles in actual radioactive Cesium (Cs) separation.

Literature Reviews to Support Ion Exchange Technology Selection for Modular Salt Processing

“…Oxygen exposure during cycling did result in a darkening of some resin beads due to polymer oxidation. The resin beads show no tendency to adhere to one another after multiple cycles and no fissures were observed in packed RF beds (Adamson, 2006) as had been observed for SuperLig ® 644 (another elutable, organic resin) during WTP testing (Fowley, 2004). RF radiolysis to 100 Mrad exposure results in darkening of the resin beads as was observed with oxygen exposure, but there was no indication of particle attrition or significant change in particle size by optical microscopy .…”

“…RF resin reacts with dissolved oxygen in the various column processing solutions (both acidic and basic), though oxidation is more facile under caustic conditions. Spectroscopic examination of RF beads after air exposure in caustic waste simulant confirmed the formation of various new oxidized carbon functionalities within the resin (Adamson, 2006). 80% oxygen consumption was observed with spherical RF columns using oxygen-saturated Hanford AP-101 simulant (Fiskum, 2006d).…”

“…Furthermore, 10% resin bed expansion was observed under these bounding conditions. During 16 chemical cycles using air-saturated simulant in a 24 inch diameter column, only a 3% resin bed height increase was observed (Adamson, 2006). It is believed that the airsaturated simulant contained significantly less soluble oxygen than the oxygen-saturated 0.5 M NaOH solution.…”

“…In addition, there is no indication of significant degradation in the resin handling and transport properties with use. Through 16 chemical cycles during hydraulic testing there was no indication of bead attrition and no change in bed permeability, despite the fact that the resin had been exposed to air-saturated feed (Adamson, 2006). No rheology tests have been conducted on spherical RF slurries.…”

Textural Characteristics of Resorcinol—Formaldehyde Resin and Temperature Behavior of Bound Water Affected by Co-Adsorbed Trifluoroacetic Acid or Pyridine in Weakly Polar Organic Media

“…The surface of an RFR particle contains a number of hydroxyl groups. Therefore, these materials can be used as ion exchangers (Adamson et al 2006;Arm et al 2006;Shady and El-Sadek 2013;Singare 2014). By contrast, the presence of a number of aromatic rings in the RFR structure allows for the use of these materials as precursors of chars and activated carbons (ElKhatat and Al-Muhtaseb 2011;Horikawa et al 2004a, b;Léonard et al 2005;Moreno et al 2013;Szczurek et al 2011;Tanaka et al 2011;Xu et al 2012;Zhang et al 2007).…”