Life cycle assessment of a catalytic converter for passenger cars

A life cycle assessment of a typical ceramic three-way catalytic converter manufactured for a Swedish passenger car is performed. The environmental impacts occurring in the life cycle of a catalytic converter, encompassing the extraction of raw materials, production of a catalytic converter, use phase, etc. are assessed. They are compared with the environmental benefits assessed throughout an average service lifetime of a catalytic converter. Inventory data show that several significant environmental impacts occur in the life cycle and are related to mining and production of the Platinum Group Elements (PGEs) used as the catalytic elements as well as to the use phase. At the current recycling rate, two of the three weighting methods used in this study indicate that the environmental impacts such as resource depletion and waste generation are not less important than the air emissions reduced at the car exhaust pipe. As its name implies, a “catalytic converter” is a “converter”. From a global and life cycle perspective, the catalytic converter is “converting” rather than reducing the environmental impacts. The results show that it is converting exhaust emissions from one place to environmental impacts in other places of the world. It is important that a life cycle perspective should be used for any “end of pipe” solution and the environmental impacts occurring in the life cycle should not be overlooked and should be weighed against the environmental benefits.