Scaling up Metal Scavenging Operations for Pharmaceutical Pilot Plant Manufactures

Functionalised silicas, used for selectively removing metal impurities in process streams, are packed in cartridges and inserted into multicartridge filters. The scavenging step that follows a catalytic reaction involves the single pass of the process stream through the multicartridge filter setup at a predetermined linear velocity and temperature. Efficiency in metal reduction as high as 98% has been so far achieved at tens of kilograms scale. Furthermore, the precious metal anchored onto the scavenger's functionalities can be recovered and refined. Our chronological development of a versatile, general, and easily scalable format for metal scavenging at process scales is described, illustrated by application in real time to a range of projects passing through our Pharmaceutical Pilot Plant, employing a variety of metals (palladium, rhodium, iridium). Benefits of the cartridge format in terms of economics and environmental impact are also initially assessed.