Unregulated Emissions with TWC, Gasoline &amp; amp; CNG

Czerwiński, Jan; Heeb, Norbert V.; Zimmerli, Yan; Forss, Anna-Maria; Hilfiker, Thomas; Bach, Christian

doi:10.4271/2010-01-1286

Cited by 20 publications

(3 citation statements)

References 15 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, non-zero emissions from diesel light-duty vehicles have been reported [100,107]. According to the literature, NH 3 forms within TWCs through reactions involving NO, CO, H 2 O, and H 2 as precursor molecules [84,85], particularly under rich conditions [86]. A wide temperature range between 250 • C and 550 • C where NH 3 selectivity was the highest has been reported [87].…”

Section: Resultsmentioning

confidence: 99%

Measurement of Light-Duty Vehicle Exhaust Emissions with Light Absorption Spectrometers

Giechaskiel,

Melas,

Franzetti

et al. 2024

Technologies

View full text Add to dashboard Cite

Light-duty vehicle emission regulations worldwide set limits for the following gaseous pollutants: carbon monoxide (CO), nitric oxides (NOX), hydrocarbons (HCs), and/or non-methane hydrocarbons (NMHCs). Carbon dioxide (CO2) is indirectly limited by fleet CO2 or fuel consumption targets. Measurements are carried out at the dilution tunnel with “standard” laboratory-grade instruments following well-defined principles of operation: non-dispersive infrared (NDIR) analyzers for CO and CO2, flame ionization detectors (FIDs) for hydrocarbons, and chemiluminescence analyzers (CLAs) or non-dispersive ultraviolet detectors (NDUVs) for NOX. In the United States in 2012 and in China in 2020, with Stage 6, nitrous oxide (N2O) was also included. Brazil is phasing in NH3 in its regulation. Alternative instruments that can measure some or all these pollutants include Fourier transform infrared (FTIR)- and laser absorption spectroscopy (LAS)-based instruments. In the second category, quantum cascade laser (QCL) spectroscopy in the mid-infrared area or laser diode spectroscopy (LDS) in the near-infrared area, such as tunable diode laser absorption spectroscopy (TDLAS), are included. According to current regulations and technical specifications, NH3 is the only component that has to be measured at the tailpipe to avoid ammonia losses due to its hydrophilic properties and adsorption on the transfer lines. There are not many studies that have evaluated such instruments, in particular those for “non-regulated” worldwide pollutants. For this reason, we compared laboratory-grade “standard” analyzers with FTIR- and TDLAS-based instruments measuring NH3. One diesel and two gasoline vehicles at different ambient temperatures and with different test cycles produced emissions in a wide range. In general, the agreement among the instruments was very good (in most cases, within ±10%), confirming their suitability for the measurement of pollutants.

show abstract

Section: Resultsmentioning

confidence: 99%

Measurement of Light-Duty Vehicle Exhaust Emissions with Light Absorption Spectrometers

Giechaskiel,

Melas,

Franzetti

et al. 2024

Technologies

View full text Add to dashboard Cite

show abstract

“…Very often in the course of research of alternative fuel powered engines, there are fluctuations in exhaust emissions, especially in cooperation with gas controllers and new generation gasoline controllers [21][22][23][24]. The problem is important, because it determines the approval process for the alternative power system.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of impact of combustion engine controller adaptation process on level of exhaust gas emissions in gasoline and compressed natural gas supply process

Dziewiatkowski

Szpica

Borawski

2020

19th International Scientific Conference Engineering for Rural Development Proceedings

View full text Add to dashboard Cite

Nowadays in many countries, where the conversion of internal combustion engines into alternative gas fuel is economically justified, the installation of CNG fuel systems dominates. According to official data, about 20 million vehicles with engines running on this fuel travel on the roads. Given the significant increase in the number of conversions carried out, special attention should be paid to the level of exhaust emissions of these vehicles. As many researchers show in their publications, combustion of this type of fuel emits less toxic compounds to the atmosphere than conventional fuels. Therefore, ecological aspects also speak for its use, which nowadays, mainly due to significant air pollution, are extremely important. In the case of conversion of vehicles with gasoline engines sequentially controlled by the engine controller, it is possible to adjust the adaptation of the parameters of this controller in various driving cycles, which affects the changes in vehicle emissions from the initial settings of this system. The article describes a number of bench tests that confirm the above statement. Extensive measuring equipment was used, which included, among others, the chassis dynamometer and exhaust gas analyzer. The results of the tests clearly showed that with the passage of using time of the vehicle (increasing mileage) one of the parameters in the control system changes significantly, which also changes the level of exhaust emissions. Unfortunately, this is an unwanted change. It has been suggested to counteract this phenomenon by emulating the lambda probe signal. The proposed solution has been implemented and tested. A series of exhaust emission tests of an engine equipped with a modified power supply system showed the correctness of the adopted solution.

show abstract

“…For passenger cars' only CNG is a reasonable choice due to its convenient handling. The specific properties of CNG like reduced exhaust emissions, 25 % lower CO 2 emissions, knock resistance, availability and also the price advantage make this fuel attractive for engine application [1,[6][7][8][9]. However, despite increasing sales of CNG powered cars in Germany, this environmentally friendly propulsion still carves out a niche existence [3].…”

Section: Introductionmentioning

confidence: 99%

Injection strategies for low HC raw emissions in SI engines with CNG direct injection

Seboldt

Lejsek

Bargende

2016

Automot. Engine Technol.

View full text Add to dashboard Cite

The energy source natural gas represents an attractive alternative fuel for SI engines due to its suitable chemical properties. But the lower performance yield and the insufficient infrastructure lead to a rejection by the customer. One approach to gain acceptance is the improvement of the driveability of the natural gas-powered vehicles. Direct injection of CNG is a technology with potential to achieve this objective. Nevertheless, the combustion concept has high requirements on injection system and mixture formation. Among other challenges the methane slip raises major issue. The compact molecular structure of the CNG's main component, methane, leads to an extremely slow reactivity, which expresses itself in a higher catalytic converter light-off temperature and thus aggravated exhaust aftertreatment. Especially, since methane's global warming potential is 21 times higher than CO 2 , the greenhouse gas footprint is getting worse again. Thus, for the future implementation of such a combustion system concept it will be necessary to compensate the limited conversion rates of the catalytic converter with low raw emissions. For this, the comprehension of the mixture formation is necessary. This paper deals with different injection strategies at part load and charged operation to achieve HC raw emissions as low as possible. The testbench experiments are executed with a two-cylinder SI engine under homogeneous stoichiometric conditions. The DI injector used for this study is a prototype model fabricated by Robert Bosch GmbH. In summary, the need of adaption of the injection strategy to the respective engine map area is becoming evident. Furthermore, various injection timings and injection splitting strategy turned out as an appropriate measure to make the most of CNG-DI's potential and to achieve low HC raw emissions.

show abstract

Unregulated Emissions with TWC, Gasoline & amp; CNG

Cited by 20 publications

References 15 publications

Measurement of Light-Duty Vehicle Exhaust Emissions with Light Absorption Spectrometers

Measurement of Light-Duty Vehicle Exhaust Emissions with Light Absorption Spectrometers

Evaluation of impact of combustion engine controller adaptation process on level of exhaust gas emissions in gasoline and compressed natural gas supply process

Injection strategies for low HC raw emissions in SI engines with CNG direct injection

Contact Info

Product

Resources

About