Journal of Chemical Technology and Biotechnology, Vol.68, No.4, 381-388, 1997
Catalysis - The Key to Waste Minimization
The drive towards greater economic and environmental efficiency in chemicals manufacture has led to a growing need for processes that produce minimal waste and avoid, as much as possible, the use of toxic and/or hazardous reagents and solvents. This has led to a reassessment of many existing technologies. Alternative processes to particular products are compared on the basis of their atom utilization and E factor (kg byproduct per kg product). The use of high-atom utilization, low-salt catalytic processes as clean alternatives to conventional technologies for the manufacture of fine chemicals is discussed. In particular catalytic oxidations and catalytic carbonylations are highlighted using citral, caprolactam, paracetamol, ibuprofen and methylmethacrylate as commercially relevant examples. The question of catalyst recovery and recycling is also addressed, e.g. with the use of redox molecular sieves as solid catalysts for liquid phase oxidations and the use of a water-soluble palladium(0)trisulfonated triphenylphosphine complex, as a catalyst for carbonylation in aqueous media.
Keywords:SELECTIVE OXIDATION;HYDROGEN-PEROXIDE;ORGANIC-SYNTHESIS;MOLECULAR-SIEVE;ZEOLITE-BETA;EPOXIDATION;ALUMINOPHOSPHATE-5;COMPLEXES