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

• Published in: Journal of Chromatography A 2015-11, Vol.1422, p.99-116
• Main Authors: Weeden, George S., Ling, Lei, Soepriatna, Nicholas H., Wang, Nien-Hwa Linda
• Format: Article
• Language: English
• Subjects: Electronic waste; Optimization; Phosphorus flame retardants; Polymer; Simulated moving bed; Size-exclusion
• ISSN: 0021-9673
• DOI: 10.1016/j.chroma.2015.09.064

•Flame retardants (FR) and a polymer (SAN) were separated with 99% purity and yield.•SMB cost is less than 3% of that for batch SEC to separate FRs from SAN.•Fast startup reduces time to steady state by 18-fold.•SMB separation cost is less than 10% of the FR purchase cost.•14 decision variables were optimized within 1min using a new method. Over 500,000t 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 1min. 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.