Refine Your Search

Topic

Author

Affiliation

Search Results

Video

Brief Investigation of SCR High Temperature N2O Production

2012-06-18
Nitrous Oxide (N2O) is a greenhouse gas with a Global Warming Potential (GWP) of 298-310 [1,2] (298-310 times more potent than carbon dioxide (CO2)). As a result, any aftertreatment system that generates N2O must be well understood to be used effectively. Under low temperature conditions, N2O can be produced by Selective Catalytic Reduction (SCR) catalysts. The chemistry is reasonably well understood with N2O formed by the thermal decomposition of ammonium nitrate [3]. Ammonium nitrate and N2O form in oxides of nitrogen (NOx) gas mixtures that are high in nitrogen dioxide (NO2)[4]. This mechanism occurs at a relatively low temperature of about 200°C, and can be controlled by maintaining the nitric oxide (NO)/NO2 ratio above 1. However, N2O has also been observed at relatively high temperatures, in the region of 500°C.
Video

On-Road Evaluation of an Integrated SCR and Continuously Regenerating Trap Exhaust System

2012-06-18
Four-way, integrated, diesel emission control systems that combine selective catalytic reduction for NOx control with a continuously regenerating trap to remove diesel particulate matter were evaluated under real-world, on-road conditions. Tests were conducted using a semi-tractor with an emissions year 2000, 6-cylinder, 12 L, Volvo engine rated at 287 kW at 1800 rpm and 1964 N-m. The emission control system was certified for retrofit application on-highway trucks, model years 1994 through 2002, with 4-stroke, 186-373 kW (250-500 hp) heavy-duty diesel engines without exhaust gas recirculation. The evaluations were unique because the mobile laboratory platform enabled evaluation under real-world exhaust plume dilution conditions as opposed to laboratory dilution conditions. Real-time plume measurements for NOx, particle number concentration and size distribution were made and emission control performance was evaluated on-road.
Video

A Pathway to Lean Engine Operation: Pre-Chamber Jet Ignition Combustion

2012-05-10
Turbulent Jet Ignition is an advanced spark initiated pre-chamber combustion system for otherwise standard spark ignition engines. Combustion in the main chamber is initiated by jets of partially combusted (reacting) pre-chamber products which provide a high energy ignition source. The resultant widely distributed ignition sites allow relatively small flame travel distances enabling short combustion durations and high burn rates. This presentation outlines development of this combustion concept in a modern normally aspirated PFI production engine. Experimental results have highlighted high thermal efficiency (42.8%), significant fuel economy improvement (>20%), low engine out NOx (<10 ppm), knock limit extension, high load capability (>13 bar IMEPn) and high speed operation (5500 rev/min). Presenter William P Attard, MAHLE Powertrain LLC
Video

SCR Deactivation Study for OBD Applications

2012-06-18
Selective catalytic reduction (SCR) catalysts will be used to reduce oxides of nitrogen (NOx) emissions from internal combustion engines in a number of applications [1,2,3,4]. Southwest Research Institute® (SwRI)® performed an Internal Research & Development project to study SCR catalyst thermal deactivation. The study included a V/W/TiO2 formulation, a Cu-zeolite formulation and an Fe-zeolite formulation. This work describes NOx timed response to ammonia (NH3) transients as a function of thermal aging time and temperature. It has been proposed that the response time of NOx emissions to NH3 transients, effected by changes in diesel emissions fluid (DEF) injection rate, could be used as an on-board diagnostic (OBD) metric. The objective of this study was to evaluate the feasibility and practicality of this OBD approach.
Video

Development of a 3rd Generation SCR NH3-Direct Dosing System for Highly Efficient DeNOx

2012-06-18
In this project funded by the Bayerische Forschungsstiftung two fundamental investigations had been carried out: first a new N-rich liquid ammonia precursor solution based on guanidine salts had been completely characterized and secondly a new type of side-flow reactor for the controlled catalytic decomposition of aqueous NH3 precursor to ammonia gas has been designed, applied and tested in a 3 liter passenger car diesel engine. Guanidine salts came into the focus due to the fact of a high nitrogen-content derivate of urea (figure 1). Specially guanidinium formate has shown extraordinary solubility in water (more than 6 kg per 1 liter water at room temperature) and therefore a possible high ammonia potential per liter solution compared to the classical 32.5% aqueous urea solution (AUS32) standardized in ISO 22241 and known as DEF (diesel emission fluid), ARLA32 or AdBlue®. Additionally a guanidine based formulation could be realized with high freezing stability down to almost ?30 °C (?
Video

Hydrocarbon Fouling of SCR During PCCI Combustion

2012-06-18
The combination of advanced combustion with advanced selective catalytic reduction (SCR) catalyst formulations was studied in the work presented here to determine the impact of the unique hydrocarbon (HC) emissions from premixed charge compression ignition (PCCI) combustion on SCR performance. Catalyst core samples cut from full size commercial Fe- and Cu-zeolite SCR catalysts were exposed to a slipstream of raw engine exhaust from a 1.9-liter 4-cylinder diesel engine operating in conventional and PCCI combustion modes. The zeolites which form the basis of these catalysts are different with the Cu-based catalyst made on a chabazite zeolite which las smaller pore structures relative to the Fe-based catalyst. Subsequent to exposure, bench flow reactor characterization of performance and hydrocarbon release and oxidation enabled evaluation of overall impacts from the engine exhaust.
Collection

Military Vehicle Technology, 2005

2010-09-15
This technical paper collection contains 49 papers detailing military vehicle technology. Topics covered include: reliability growth for military vehicles, upgrading readiness, rapidly installed fluid transfer system, robotic technologies, electrical systems modeling and simulation, nanofluid research, and more.
Collection

Latest Advances for Commercial Vehicle Drivetrains, Powertrains, and Transmissions 2010

2010-09-27
This technical paper collection contains 53 technical papers. Topics covered include engine exhaust aftertreatment and integration; hybrid vehicle integration and optimization; powertrain and drivetrain NVH; advanced transmission and driveline component design; diesel engine system design; fuel economy; alternative fuels; and advanced engine component design.
Collection

High Efficiency IC Engines, 2011

2011-04-12
The 10 papers in this technical paper collection discuss high efficiency IC engines. Topics include: fuel reactivity controlled compression ignition (RCCI) combustion in light- and heavy-duty engines; fuel effects on reactivity controlled compression ignition (RCCI) combustion at low load; advantages of variable compression ratio in internal combustion engines; piston and valve deactivation for improved part load performances of internal combustion engines; and more.
Collection

Commercial Vehicle - Engine Exhaust Aftertreatment and Integration, 2012

2012-10-02
The 11 technical papers in this collection cover technologies that address the treatment of engine exhaust emissions to meet commercial vehicle requirements. The scope covers developments in catalysis, materials, controls, and integration with the complete engine/vehicle system.
Collection

Powertrains, Fuels & Lubricants - Mixing-Controlled CI Combustion, 2012

2012-09-18
The 8 technical papers in this collection feature CI combustion technologies distinguished by 1) mixing processes that influence combustion; and 2) combustion phasing closely coupled to the timing of fuel injection. This includes the impact of the fuel injection and jet-mixing processes; impact of swirl/spray targeting on mixing processes; combustion chamber/engine geometry optimization; sources of combustion inefficiency; and the impact of operating conditions.
Collection

Powertrains, Fuels & Lubricants - Advanced Lubricant Research & Development, 2012

2012-09-18
The 8 technical papers in this collection contain lubricant research and development that is necessary to advance and support new automotive engineering technology. Topics include grease designed to reduce vehicle noise, characteristics of low viscosity engine oil that impact fuel economy and reliability and the characterization of diesel particulate filter ash and how this influences the development of filter regeneration strategies.
Collection

Powertrains, Fuels & Lubricants - Advanced Vehicle Technology Competitions, 2012

2012-09-18
The 13 technical papers in this collection cover the work done by student teams in the EcoCAR 2: Plugging in to the Future competition series, sponsored by General Motors and the U.S. Department of Energy. This includes powertrain architecture selection, control system modeling and simulation, and energy storage system design and component packaging.
Collection

GHG and Other Gaseous Emisions from Engines, 2014

2014-04-01
This technical paper collection focuses on the general topic of combustion engine gaseous emissions (regulated and non-regulated). This includes well-to-wheels CO2 production for alternative technologies, fuel economy and all greenhouse gas emission research. It also includes hydrocarbon species and specific NOx species production over aftertreatment devices as a result of changes in fuel specification and the inclusion of bio-derived components and consideration of secondary emissions production (slip) as a result of aftertreatment.
Collection

High Efficiency IC Engines, 2013

2013-04-09
The 24 papers in this technical paper collection focus on technologies such as advanced and partially mixed combustion, cooled EGR boosting, ignition and direct injection technologies, pressure boosting, intelligent combustion, thermal efficiency including waste heat recovery, fully variable valvetrains.
X