90% value recovery of Pd catalyst
A pharmaceuticals manufacturer developed a route with a palladium-catalysed cross-coupling reaction. The final product was isolated with suitably low palladium levels, but the mother liquors contained 500 ppm palladium. The client was interested in the cost-effective recovery of the palladium from the stream to improve the sustainability of the process.
Screening of the PhosphonicS scavenger library identified Phos-04 as the optimal scavenger. Optimisation process and lab-scale trial identified and validated the experimental conditions where 98% of the palladium was recovered from the mother liquors with a 6% palladium loading on the Phos-04 scavenger. The recovery of 40 kg of palladium required 700 kg of Phos-04 scavenger.
A business case was built upon the calculation that 96% of palladium was recovered from the liquors. After the scavenging and refining processes, this translated into 90% value recovery, dramatically reducing the effective cost of the palladium catalyst.