Diagram courtesy of: The Association for Emissions Control by Catalyst (https://www.aecc.eu/wp-content/uploads/2017/11/2017-AECC-technical-summary-on-GPF-final.pdf) Shown here as well. Diagram courtesy of Peter Duncan, General Manager, Market Research, of Johnson Matthey, IPMI 2016 16 Catalytic Converters By Becky Berube Keeping it Simple May Not Be So Easy with the Cats of the Future Where the new recycling challenge emerges is the complexity of the exhaust system architectures for both gasoline and diesel engine vehicles. The new com- ponents may all look like cats, but they do not all have value; processing some of these components with others can even ruin a load. Gasoline engines emit lower soot than diesel engines under typical driving conditions. Most gasoline engine vehi- cles contain a combination of traditional ceramic three-way catalyst (TWC). How- ever, gasoline particulate filters (GPFs) are being added to these systems. Diesel systems can have up to four components to handle emissions: the diesel oxidation Loadings and Trends Basically, the tighter the emission standards, the higher the PGM (platinum group metal) loadings or cat value. The United States is predominantly gasoline engine vehicles; whereas, Europe is pre- dominantly diesel engine vehicles. More than 90 percent of catalytic converter applications are made of a ceramic mono- lithic substrate, or honeycomb material; the remainder are metallic monolith sub- strates, commonly called foils or wires. The problem is no longer being able to identify and price ceramic and metallic converters, but rather something differ- ent. Two years ago, we were part of an auto catalyst technology seminar, held in Atlanta, GA, with one hun- dred and four delegates and where eigh- teen presentations were given by industry leaders in the field of automotive exhaust catalyst. One of the greatest take-aways from that seminar was a presentation by Peter Duncan, General Manager of Mar- ket Research for Johnson Matthey, on the future complexities of auto cat systems and what it will mean for recycling. What I want to share with you in this article, is an overview of how exhaust systems and converter loadings are changing. If you are selling by the piece, there is more room than ever for shades of gray when it comes to pricing. We encourage our customers to sell convert- ers on assay, or the precious metal con- tent within the converter, which elimi- nates the grading subjectivity. catalyst (DOC), a diesel particulate fil- ter (DPF), a lean NOx trap (LNT), and some type of selective catalytic reduc- tion catalyst (SCR) or selective cata- lytic reduction filter (SCRF). In terms of PGM loadings, the DOCs, diesel oxidation catalysts are like regular gasoline catalysts, having even higher loadings. DPFs, diesel par- ticulate filters, have some value, gen- erally low. DPFs can have one of two bases: aluminum titanate (ATI) or sili- con carbide (SiC). Silicon carbide- based DPFs must be processed sepa- rately at higher temperatures with oxi- dation to avoid combustion. This rep- resents higher recycling costs and All the above-mentioned compo- nents, which resemble catalytic con- verters, have various amounts of PGMs, some, like SCRs and SCRFs are PGM-free. See the diagrams below. You may be wondering about future powertrains and how they may affect the demand and use of PGMs. In general, these powertrains are unlikely to com- pletely replace the internal combustion engine (ICE) market but will for the most part contain similar or higher PGM load- ings. Gasoline turbo direct injection (GTDI) engines have better fuel effi- ciency but higher hydrocarbon and partic- ulate emissions; these will result in higher PGM use. Lean burn gasoline (LBG) engines also have better fuel efficiency but higher NOx emissions requiring LNTs and thus more PGM use. Battery electric vehicles (BEV) require no PGMs. Hybrid Future Powertrains and PGMs Whether you are buying or selling converters by the piece, these complex exhaust system architectures are begin- ning to pose a problem in identifying, grading, and pricing. This to say, buyer and seller beware. when commingled can lead to lower metal yields. SCRs and SCRFs, selective cata- lytic reduction catalysts and filters are PGM free, having zero value. LNTs, Lean NOx traps have some value, albeit low.