Pilot Plant Studies on the Recovery of Caprolactam by Reverse Osmosis

The performance of a polyamide-based thin film composite reverse osmosis membrane (RO) in a spiralwound element BW3025 (FilmTec) for the recovery of caprolactam from an aqueous solution have been investigated. The experimental tests of the RO membrane were carried out using pure water (permeate from a nanofiltration system), brackish water (2000 ppm NaCl) and caprolactam solution (1000 ppm) and were evaluated based on the permeate flux and rejection of the dissolved solids at different transmembrane pressures. The RO membrane provided a rejection of 99.47% for brackish water and 99.74% for caprolactam and an average permeate flux of 65 dm3/ h. It was also found that the RO membrane element has experienced no fouling during the experiments.