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Natural gas and biogas alone or in combination with conventional liquid fuels (dual-fuel applications) are advanced alternative solutions to diesel and gasoline in the future. Burning of natural- or biogas produces less CO2 emissions per energy unit, and particulate matter emissions can also be reduced compared to more traditional liquefied fuels. This decrease in engine out emissions can be utilized as a tool to meet tightening emission limits and to improve the air quality locally in the areas with big challenges especially related nitrogen oxide and particulate emissions. In the present study the focus was on the development of catalytic emission control technology for both mobile and stationary lean-burn natural gas applications. Main activities were related to the oxidation catalyst and its improvements towards sulfur poisoning and to enhance methane light-off performance.

The emission regulations for mobile applications will become stricter in Euro 4 - 6 levels and require the use of active aftertreatment methods (deNOx and DPF) in addition to passively operating diesel oxidation catalysts (DOC). Vanadium-SCR (V-Selective Catalytic Reduction) catalysts based on stabilized TiO₂-WO₃ raw materials and tailored preparation methods were first evaluated by the laboratory experiments. Conventional V-SCR catalysts were durable up to about 600°C but the developed catalyst stand hydrothermal ageing up to 700°C without losses of activity. Simultaneously, the performance at 250 - 450°C was about the same as with the traditional V-SCR catalyst and the SCR selectivity at 450 - 600°C was high with a low NH₃ oxidation tendency. Coated V₂O₅/TiO₂-WO₃ catalysts (ceramic and metallic substrates) were evaluated with a 4.9 L engine by engine bench experiments.

The emission regulations for mobile applications become stricter in Euro-IV to Euro-VI levels. Carbon monoxide and hydrocarbon can be removed by efficient Diesel Oxidation Catalysts (DOC) but Particulate Matter (PM) and NOx are more demanding requiring the use of active methods (urea-SCR and DPF) which will be world-wide implemented in the 2010's. Durable, coated V-SCR catalysts are based on stabilized raw materials and tailored preparation methods. Coated V2O5/TiO2-WO3 catalysts (ceramic 300/400 cpsi and metallic 500/600 cpsi) were evaluated by laboratory and engine bench experiments. Traditional V-SCR catalysts are durable up to about 600°C and have a high efficiency at 300°C-500°C. SCR activities were tailored to be higher also at 200°C-300°C or 500°C-600°C. The use of thermal stabilizers or the vanadium loading variation enabled the changes in operation window and stability.

This presentation will introduce the overall goals of the EcoCAR competition in brief, and will go into the third and final year of the competition in detail. The final year of competition saw teams refining and testing their student-built advanced technology vehicles including hybrids, plug-in hybrids, hydrogen fuel cell PHEVs and one battery electric. Important events, such as the Spring Workshop chassis dynamometer testing event at the U.S. Environmental Protection agency, as well as significant competition results, such as vehicle performance, consumer acceptability and efficiency will be presented. Presenter Patrick Walsh

The aim of this paper is to analyze the quantitative impact of fuel sulfur content on particulate oxidation catalyst (POC) functionality, focusing on soot emission reduction and the ability to regenerate. Studies were conducted on fuels containing three different levels of sulfur, covering the range of 6 to 340 parts per million, for a light-duty application. The data presented in this paper provide further insights into the specific issues associated with usage of a POC with fuels of higher sulfur content. A 48-hour loading phase was performed for each fuel, during which filter smoke number, temperature and back-pressure were all observed to vary depending on the fuel sulfur level. The Fuel Sulfur Content (FSC) affected also soot particle size distributions (particle number and size) so that with FSC 6 ppm the soot particle concentration was lower than with FSC 65 and 340, both upstream and downstream of the POC.

Legislations worldwide have started imposing stringent emission standards for particulate matter (PM) emitted by diesel engines. The main reason for these actions is the adverse effects on human health caused by particle emissions. Conventional ceramic Diesel Particulate Filters (DPF) have proven exceptionally effective in reducing particulate emissions with efficiencies of 90% or more. However, these filters require regular active regenerations as well as periodical ash removal in order to avoid a blockage of the exhaust line. These procedures are both costly and complex and as a result alternative aftertreatment solutions have been developed. One of these solutions is the Particle Oxidation Catalyst, POC-X. The main aim of the POC-X is not to equal the high efficiencies of the DPF, but to achieve the best possible particle reduction without creating the risk of blocking or the need for complex filter regeneration procedures.

The emission regulations for mobile off-road applications are following on-road trends by a short delay. The latest Stage 3B and 4 emission limits mean a gradual implementation of oxidation and SCR catalysts as well as particulate filters with off-road machines/vehicles in the 2010s. The driving conditions and test cycles differ from on-road truck applications which have been the first design base for off-road aftertreatment technologies. Aftertreatment systems for Stage 4 were first analyzed and they will include oxidation catalysts, a NOx reduction catalyst (SCR or LNT), a particulate filter and possibly units for urea hydrolysis and ammonia slip removal. The design and durability of V₂O₅/TiO₂-WO₃ catalysts based on metallic substrates were investigated by engine bench and field experiments. NOx emissions were measured with 6.6 and 8.4 liters engines designed for agricultural and industrial machinery.