Measurement of Catalytic Converter Performance Using Exhaust Gas Sensors with Modified Characteristics

1993 ◽  
Author(s):  
Peter. G. Eastwood
Keyword(s):  
Gas Sensors ◽  
Catalytic Converter ◽  
Exhaust Gas

scholarly journals Lean-Burn Natural Gas Engines: Challenges and Concepts for an Efficient Exhaust Gas Aftertreatment System

2020 ◽  
Author(s):  
Patrick Lott ◽  
Olaf Deutschmann
Keyword(s):  
Natural Gas ◽  
Carbon Dioxide Emissions ◽  
Rational Design ◽  
Catalytic Converter ◽  
Pollutant Emissions ◽  
Exhaust Gas ◽  
Lean Burn ◽  
Aftertreatment System ◽  
Natural Gas Engines ◽  
Exhaust Gas Aftertreatment

AbstractHigh engine efficiency, comparably low pollutant emissions, and advantageous carbon dioxide emissions make lean-burn natural gas engines an attractive alternative compared to conventional diesel or gasoline engines. However, incomplete combustion in natural gas engines results in emission of small amounts of methane, which has a strong global warming potential and consequently makes an efficient exhaust gas aftertreatment system imperative. Palladium-based catalysts are considered as most effective in low temperature methane conversion, but they suffer from inhibition by the combustion product water and from poisoning by sulfur species that are typically present in the gas stream. Rational design of the catalytic converter combined with recent advances in catalyst operation and process control, particularly short rich periods for catalyst regeneration, allow optimism that these hurdles can be overcome. The availability of a durable and highly efficient exhaust gas aftertreatment system can promote the widespread use of lean-burn natural gas engines, which could be a key step towards reducing mankind’s carbon footprint.

Design and Experimental Study on the Urea-SCR Converter Exhaust System of the Marine Diesel Engine

2013 ◽  
Vol 291-294 ◽  
pp. 1889-1894
Author(s):  
Lei Jiang ◽  
Jun Huang
Keyword(s):  
Experimental Study ◽  
Diesel Engine ◽  
Pressure Loss ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Marine Diesel Engine ◽  
Exhaust Gas ◽  
Marine Diesel ◽  
New Type ◽  
Design Requirements

Urea-SCR catalytic converter can effectively reduce the NOx emission of diesel engines, but meanwhile catalytic converter will cause some pressure loss in the exhaust system, which has negative influences on the engine performances. In this paper, the method of theoretical analysis calculated the pressure loss of the SCR catalytic converter, and designing a new type of exhaust gas pipe. Through the test to meet the design requirements,the results can provide a reference for optimum design of SCR catalytic converters and assembling.

Numerical and Experimental Analysis of the Mass Transfer in Exhaust Gas Sensors

2007 ◽  
Author(s):  
Marc Brück ◽  
Gunda Mader ◽  
Manfred Piesche ◽  
Sascha Klett
Keyword(s):  
Mass Transfer ◽  
Gas Sensors ◽  
Experimental Analysis ◽  
Exhaust Gas

Analysis of the Impact of the New Emissions Limits on the Temperatures of the Vehicle Floor

2012 ◽  
Vol 152-154 ◽  
pp. 976-981
Author(s):  
Gustavo Inácio Bicalho ◽  
Bruno de Souza Baptista ◽  
Felipe Vereza Lopes da Silva ◽  
Sérgio de Morais Hanriot ◽  
Luben Cabezas-Gómez ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Catalytic Converter ◽  
Exhaust System ◽  
Pollutant Emissions ◽  
Exhaust Gas ◽  
Air Conditioning System ◽  
Industrial Economy ◽  
Emission Limits ◽  
Gas Recirculation ◽  
The Impact

The Kyoto Protocol established the reduction of pollutant emissions limits for all sectors of industrial economy in 8%, compared to 1990´s levels, to be adopted in the period between 2008 and 2012. Individual countries defined a progressive scale for the emission reduction applied to automotive vehicles. These new emission limits are reached altering the calibration of the Electronic Central Unit (ECU), altering the volume and the composition of the catalytic converters and also adding new components to the engine, such as EGR (exhaust gas recirculation) system and phasing sensor. This work evaluates the impact of these modifications in the exhaust system temperatures and in the peripherical devices. In order to meet the requirements of the new emissions limits, the volume of the catalytic converter is higher, increasing the heat rejected. It provokes a temperature raise on the exhaust system and under the vehicle pavement, which impact the functionality of some components and also the passenger's thermal comfort. It is observed that the new emission standards in Brazil resulted in an increase of the vehicle temperatures, affecting the passengers’ thermal comfort, and eventually producing more emissions due to the use of an air conditioning system.

Measurement of Exhaust Gas Temperatures: Theoretical and Experimental Analysis

2002 ◽  
Author(s):  
Nicolo` Cavina
Keyword(s):  
Experimental Analysis ◽  
Measurement Errors ◽  
Control Strategies ◽  
Catalytic Converter ◽  
Model Identification ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Exhaust Manifold ◽  
Si Engine ◽  
Polluting Emissions

The optimal management of the three-way catalytic converter is today widely recognized as one of the means to further reduce Spark Ignition (SI) engine polluting emissions, and therefore to respect future emission regulations. Its conversion efficiency is strictly dependent on the operating temperature, and most engine control strategies are today either based on mathematical models that determine such temperature as a function of the engine operating conditions, or on its direct measurement. It is therefore useful to investigate the errors that could arise when measuring exhaust gas temperatures, either during model identification tests or on board the vehicle. The paper presents a theoretical and experimental analysis on the phenomena that could lead to relevant measurement errors in such applications. A physical model of the heat transfer phenomena that take place in the exhaust manifold has been developed to estimate both the exhaust gas temperatures and the error that would arise while measuring them with typical sensors such as thermocouples. The exhaust manifold of a 1.2 liter SI engine was equipped with different types of sensors for the model identification and validation phases.

scholarly journals Molecular hydrogen (H<sub>2</sub>) emissions and their isotopic signatures (H/D) from a motor vehicle: implications on atmospheric H<sub>2</sub>

2010 ◽  
Vol 10 (2) ◽  
pp. 3021-3051 ◽  
Author(s):  
M. K. Vollmer ◽  
S. Walter ◽  
S. W. Bond ◽  
P. Soltic ◽  
T. Röckmann
Keyword(s):  
Molecular Hydrogen ◽  
Motor Vehicle ◽  
Catalytic Converter ◽  
Anthropogenic Activities ◽  
Strong Dependence ◽  
Isotope Analysis ◽  
Geographical Location ◽  
Enrichment Factors ◽  
Exhaust Gas ◽  
Vehicle Exhaust

Abstract. Molecular hydrogen (H2), its isotopic signature (deuterium/hydrogen, δD), carbon monoxide (CO) and other compounds were studied in the exhaust of a passenger car engine fuelled with gasoline or methane and run under variable air-fuel ratios and operating modes. H2 and CO concentrations were largely reduced downstream of the three-way catalytic converter (TWC) compared to levels upstream, and showed a strong dependence on the air-fuel ratio (expressed as lambda, λ). The isotopic composition of H2 ranged from δD=–140‰ to δD=–195‰ upstream of the TWC but these values decreased to –270‰ to –370‰ after passing through the TWC. Post-TWC δD values for the fuel-rich range showed a strong dependence on TWC temperature with more negative δD for lower temperatures. These effects are attributed to a rapid temperature-dependent H-D isotope equilibration between H2 and water (H2O). In addition, post TWC δD in H2 showed a strong dependence on the fraction of removed H2, suggesting isotopic enrichment during catalytic removal of H2 with enrichment factors (ε) ranging from –39.8‰ to –15.5‰ depending on the operating mode. Our results imply that there may be considerable variability in real-world δD emissions from vehicle exhaust, which may mainly depend on TWC technology and exhaust temperature regime. This variability is suggestive of a δD from traffic that varies over time, by season, and by geographical location. An earlier-derived integrated pure (end-member) δD from anthropogenic activities of –270‰ (Rahn et al., 2002) can be explained as a mixture of mainly vehicle emissions from cold starts and fully functional TWCs, but enhanced δD values by >50‰ are likely for regions where TWC technology is not fully implemented. Our results also suggest that a full hydrogen isotope analysis on fuel and exhaust gas may greatly aid at understanding process-level reactions in the exhaust gas, in particular in the TWC.

Sign in / Sign up

Export Citation Format

Share Document