Size-exclusion simulated moving bed for separating organophosphorus flame retardants from a polymer

Over 500,000 t of flame retardants in electronic wastes are consigned to landfills each year. A room-temperature, size-exclusion simulated moving bed (SEC-SMB) was developed to recover high purity (>99%) flame retardants with high yield (>99%). The SSWD method for ternary mixtures was developed for SEC-SMB. Fourteen decision variables were optimized to obtain the lowest separation cost within 1 min. The estimated cost is less than 10% of the purchase cost of the flame retardants. The estimated cost of the optimized SEC-SMB is less than 3% of that of a conventional batch SEC processes. Fast start-up methods were developed to reduce the SMB start-up time by more than 18-fold. SEC-SMB can be an economical method for separating small molecules from polymers.