Emitec, the German catalyst manufacturer founded in 1986 as a joint venture between Siemens and GKN, generally has a low profile but has nevertheless become one of the biggest catalyst manufacturers in the world, employing over 800 people in Germany and the US. Matthew Beecham talked with Dipl. Ing. Wolfgang Maus, Emitec's CEO about the current market and technical trends in automotive emission technologies.

Emitec's success has been built on its pioneering work building catalytic converters with metal substrates, and began with its launch of the electrically-heated Emicat device in 1994, which showed how heating a catalyst offered major improvements in emissions reduction. One of its recent inventions is a pre-turbo catalyst for diesel engines that makes use of the higher exhaust gas temperatures found before the turbocharger. The company is especially interested in the challenges of emissions reduction for diesel engines and sees major business potential there, both in Europe and eventually the US. Emitec is also working on emissions reduction for HCCI engines.

just-auto: How do you see OE diesel exhaust content evolving over the next few years?

Wolfgang Maus: One best guess is to extrapolate the development of exhaust gas aftertreatment over the last 20 years. Generally speaking, early predictions that components and cost would grow in correlation with the more stringent emission levels did not actually happen. Relatively, and in most cases absolutely, converter volumes and cost have been even reduced after innovative technologies have become mature. Emerging markets will grow fast and mature regions will show a demanding technology complexity.

just-auto: The increasing number of catalytic converters inevitably leads to an increasing demand for noble metals. I guess that limited resources and correspondingly high prices are prompting the development of converters with higher efficiency and lower catalyst ageing. Is that correct?

Wolfgang Maus: Yes, that tendency continues and can be read from the past where closed couple converters, thinner walls and high cell densities have significantly increased efficiency and thus lowered cost. Now the risk of still rising noble metal prices will be a threat for NOx-Adsorbers and this supports the investments into SCR technologies.
just-auto: Could you see gasoline engines going lean for fuel economy reasons? I guess De-NOx technology could be used here. How do you see OE gasoline exhaust content evolving through this decade?

Wolfgang Maus: Diesel technology set tough fuel consumption benchmark targets for gasoline engines and also in normal driving cycles for hybrids. Fuel prices continue to go up and a significant part of that rise is taxes. The political target to reduce CO2 emissions might be enforced by more taxes. Both most probably will increase the pressure to go lean. One has to take into account that gasoline engines emit significantly more NOx engine-out emissions than diesel engines. So some progress is needed urgently here. Therefore it is not unlikely that even SCR will be given a deeper thought for gasoline engines.

just-auto: As we see it, manufacturers are working toward positioning the catalytic converter as close to the manifold as possible thereby making the catalyst smaller. Catalytic converters are also becoming more and more integrated into the manifold. Is this correct? What trends are occurring in the positioning of catalytic converters?

Wolfgang Maus: Close coupled is state-of-the-art today. Stating this, it is also true that the position behind the manifold or even the turbocharger will not be close enough for diesel and gasoline engines with innovative combustion processes and therefore even colder exhaust gas temperatures. New challenges with regard to cold-start efficiency will come up for all lean-burn concepts. Pre-turbocharger catalysts will be one innovation to satisfy that thermodynamic must. More development efforts are needed to solve that cold-start issue with regard to particulate reduction.

just-auto: Emitec has pushed back the technical boundaries on a number of fronts over the years, recently introducing its METALIT catalytic converter. Could you tell us the genesis to this innovation, what is novel about it and its benefits?
Wolfgang Maus:  The 'secret' behind our continuous product innovations is anticipating the 'next' needs. As touched on in the beginning, environmental consciousness creates tougher environmental limits and those create higher expectations for a better and healthier environment again. Engine technology has been forced to provide lower engine-out emissions, which has to be included into the future demand. Last but not least, we love cars and acknowledge that mobility has been and will be a main driver for prosperity. In that way we take the risk and develop components our customers might not yet want. Turbulent flow substrates fell under this category. After about three years of development and seven years of introduction they are now in real mass-production with Volkswagen's terrific new common rail engines.

just-auto: What technical developments are occurring in the aftermarket for catalysts? How fast is this aftermarket growing?

Wolfgang Maus: The latest scandal about (inferior) retrofit particulate filter in Germany will draw attention on the quality of aftermarket converters. We expect in-field tests and inspections in order to avoid fake-emission-aftertreatment. High-quality robust OE series components did already reduce the demand for aftermarket parts. At the same time the demand for retrofitting diesel with the latest technologies will have a faster influence on critical NO2 and particulate limits in cities. Therefore new markets for PM traps and SCR retrofit will be very attractive.

just-auto: I guess recycling of used catalytic converters is another important challenge. How is the automotive industry addressing this?

Wolfgang Maus: Precious metals are highly expensive and a kind of strategic issue to provide cleaner vehicles for reasonable cost. OE and recycling specialists developed this business; in particular, for metallic catalysts superior processes have been introduced. They are more effective and environmentally safe with almost no waste.

just-auto: Although, on the face of it, fuel cell technology presents potential threats to catalyst technology, what is the reality/outlook for the catalytic converter? What do you see as the major challenge for vehicle catalysts over the next five years?

Wolfgang Maus: Fuel cell technology still has the unsatisfied need of cheap hydrogen fuel. Rising oil prices in the near future will chance that scenario. Other decisive factors include the hydrogen storage capability and even the predicted mass production cost of the total propulsion system. Also the huge amount of platinum needed will be an issue.

just-auto: As we understand it, Emitec has a 15% share of the worldwide catalyst substrate and PM filter market. Could you give us an idea of your competitor's market shares either at a global level or regionally, i.e. Europe?

Wolfgang Maus:  Since the foundation of Emitec with three employees about 20 years ago, our competition has been two ceramic substrate companies serving the markets. Today the battleground is much more advanced: It is all about enhanced heat and mass transfer, turbulent effects or continuous PM reduction technologies.

just-auto: In the run-up to the introduction of Euro 5 in 2009, how do you see the particulate filter technology evolving? That is, do you see close-coupled filters as the preferred position versus the under-floor position?

Wolfgang Maus: One significant change for aftertreatment concepts can be forecasted already. Components must be as close coupled as possible to the combustion chamber in order to avoid electrically-heated catalysts for light-off. Secondly, avoidance of high PM emissions will be achieved not only with more advanced combustion processes but also tuning the PM-NOx trade-off to high NOx emissions which improves engine efficiency and thus fuel consumption. Therefore the other two assumptions are that SCR - being CO2-neutral - quite probably will get more attention, and particulates, being almost invisible then, can be 'burned' continuously and 'cold'.

just-auto: What about coated filters versus uncoated using additives; do you see strong OEM preferences?

Wolfgang Maus:  Oxidation effects without De-NOx technology will be counterproductive for achieving low NO2 emissions for the EU NO2 emission reduction initiative by 2010.

just-auto: Are there cost implications, too? For instance, do you see cordierite substrates becoming the main alternative to more expensive siliciumcarbid substrates?

Wolfgang Maus:  Taking into consideration that the industry will strive to use the lowest cost and reliably working filter technology, to come from SiC and to go to Cordierit is a natural target. The next one could be to avoid the fuel consumption and CO2-emission of the wall-flow filter regeneration and use partial-flow filter technology which results in a much smaller component. Some 100,000 filters of that technology are performing successfully in two truck brands. About 200,000 partial-flow filters are demonstrating, how robust that design works as retrofit.

just-auto: Could you see other technologies emerging, such as particulate electro-filters?

Wolfgang Maus: In contrast, electro-filters are quite sensitive to run and are known to be useful to agglomerate the PMs. To get rid of that kind of soot will be the next challenge.

just-auto: Finally, do you see any other trends emerging in the automotive exhaust systems industry?

Wolfgang Maus: A real breakthrough for diesel and gasoline engines - fulfilling the expectations of lowest fuel consumption possible and therefore being lean-burn - will be a fully continuously-working aftertreatment integrating PM-reduction as module 1, plus module 2, the NOx-conversion. The first steps have been taken by demonstrating, together with MAN and AVL, the so called SCRi technology, the first combined and continuously working De-NOx-soot processing.

See also: RESEARCH ANALYSIS: Exhausting review of emission technologies

 Global market review of exhaust systems - forecasts to 2014