PROJECT DESCRIPTION
BACKGROUND
Catalytic converters contain a catalyst (usually composed of precious metals, known as "PGMs" : Platinum Group Metals) deposited on a ceramic support (SiO2 - Al2O3 - MgO). Used converters are a waste product which, in the absence of a commercial recycling process, end up in landfills as part of the other shredded residues remaining from the treatment of end-of-life vehicles. These converters are fitted on all petrol-engine vehicles since 1993 and diesel-engine vehicles since 1997. More and more of those vehicules are approaching the end of lifetime and must be desmantled in a way that respects the European regulation which requires that breakers and crushers recycle 80% of the car’s weight by 2005 and 85% by 2015.
OBJECTIVES
The project aimed to demonstrate, at semi-industrial scale, the technical and economic feasibility of a recycling process for catalytic converters. The process was designed to enable the separation and recovery of the precious metals (representing approximately 0.2% of the weight of the converter), the metallic tubing and the ceramic support, in the form of an aluminium salt in solution. This solution could be used as a coagulant in waste water treatment plants. The technique was aimed at encouraging the treatment and recycling of catalytic converters in the European Community, thereby contributing to efforts to improve the handling of end of life vehicles. The setting-up of a European network for the collection of used catalytic converters was another objective of the project, since the economic faisibility of the project required a large quantity of converters to be collected. This collection was expected to be difficult and costly, as the converters were scattered across a wide area.
RESULTS
The technical objectives were relatively easy to achieve. The following steps were taken: exploratory tests at the laboratory to define a method of processing ; laboratory-scale optimisation of the various steps of the process; validation on an industrial pilot scale; and development of an analytical follow-up process. The average results obtained gave the following precious metal recovery rates : Platinum, 98% ; Palladium, 97% ; Rhodium, 98%. The ceramic support and the case of the converter were also recycled in the process. The second objective was the setting-up of an industrial unit. However, the catalytic exhaust collection level required for economic feasibility is 3 million units, whilst only 100,000 could be collected in 1999. There was two reasons for this: firstly, the European market had not yet reached maturity (cars fitted with catalytic converters had not yet reached the end-of-life stage) ; supplies of used catalytic exhausts were widely dispersed and therefore difficult to collect. The original application gave priority to «industrial» expenditure. But, once the process was assessed within the fixed calendar deadlines, it turned out that the aspect of the project linked to collection of used converters was much more awkward and complex than expected. The planned investment was therefore postponed and efforts were diverted to the setting-up of a collection network. A « CYCLEON certified collector » label was created and awarded by contract to a series of automobile scrap collection companies who work with dealers, agents, garages, etc. Contracts were also signed with certain breakers or scrap merchants who wanted to come into line with European environmental changes. CYCLEON established a series of partnerships with other Eurpean countries and has become a major player in the recycling of used catalytic converters in the South of Europe.The technical objectives were relatively easy to achieve. The following steps were taken: exploratory tests at the laboratory to define a method of processing ; laboratory-scale optimisation of the various steps of the process; validation on an industrial pilot scale; and development of an analytical follow-up process. The average results obtained gave the following precious metal recovery rates : Platinum, 98% ; Palladium, 97% ; Rhodium, 98%. The ceramic support and the case of the converter were also recycled in the process. The second objective was the setting-up of an industrial unit. However, the catalytic exhaust collection level required for economic feasibility is 3 million units, whilst only 100,000 could be collected in 1999. There was two reasons for this: firstly, the European market had not yet reached maturity (cars fitted with catalytic converters had not yet reached the end-of-life stage) ; supplies of used catalytic exhausts were widely dispersed and therefore difficult to collect. The original application gave priority to «industrial» expenditure. But, once the process was assessed within the fixed calendar deadlines, it turned out that the aspect of the project linked to collection of used converters was much more awkward and complex than expected. The planned investment was therefore postponed and efforts were diverted to the setting-up of a collection network. A « CYCLEON certified collector » label was created and awarded by contract to a series of automobile scrap collection companies who work with dealers, agents, garages, etc. Contracts were also signed with certain breakers or scrap merchants who wanted to come into line with European environmental changes. CYCLEON established a series of partnerships with other Eurpean countries and has become a major player in the recycling of used catalytic converters in the South of Europe.