3D printed catalytic converters with enhanced activity for low-temperature methane oxidation in dual-fuel engines

2019 ◽

Vol 141 (8) ◽

Author(s):

Ehsan Arabian ◽

Thomas Sattelmayer

Keyword(s):

Low Temperature ◽

Methane Oxidation ◽

Batch Reactor ◽

Combustion Method ◽

Experimental Results ◽

Dual Fuel ◽

Reactor Model ◽

Lean Premixed ◽

Temperature Levels ◽

No2 Formation

A dual fuel engine concept with lean premixed methane–air charge ignited by a diesel pilot flame is highly promising for reducing NOx and soot emissions. One drawback of this combustion method, however, is the high nitric dioxide (NO2) emissions observed at certain operating points. The conditions leading to increased NO2 formation have been investigated using a batch reactor model in cantera. It has been found that the high emission levels of NO2 can be traced back to the mixing of small amounts of quenched CH4 with NO from the hot combustion zones followed by postoxidation in the presence of O2, requiring that the temperatures are within a certain range. NO2 formation in the exhaust duct of a test engine has been modeled and compared to the experimental results. The well-stirred reactor model has been used that calculates the steady-state of a uniform composition for a certain residence time. An appropriate reaction mechanism that considers the effect of NO/NO2 on methane oxidation at low temperature levels has been used. The numerical results of NO–NO2 conversion in the duct at low temperature levels show good agreement with the experimental results. The partial oxidation of CH4 can be predicted well. It can be shown that methane oxidation in the presence of NO/NO2 at low temperature levels is enhanced via the reaction steps CH3+NO2⇌CH3O+NO and CH3O2+NO⇌CH3O+NO2. In addition, the elementary reaction HO2+NO⇌NO2+OH is the important NO oxidizing step.

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Investigation of NO2 Formation Kinetics in Dual-Fuel Engines With Lean Premixed Methane-Air Charge

Volume 2: Emissions Control Systems; Instrumentation, Controls, and Hybrids; Numerical Simulation; Engine Design and Mechanical Development ◽

10.1115/icef2018-9581 ◽

2018 ◽

Author(s):

Ehsan Arabian ◽

Thomas Sattelmayer

Keyword(s):

Low Temperature ◽

Methane Oxidation ◽

Batch Reactor ◽

Combustion Method ◽

Experimental Results ◽

Dual Fuel ◽

Reactor Model ◽

Lean Premixed ◽

Temperature Levels ◽

No2 Formation

A dual fuel engine concept with lean premixed methane-air charge ignited by a diesel pilot flame is highly promising for reducing NOx and soot emissions. One drawback of this combustion method, however, is the high nitric dioxide (NO2) emissions observed at certain operating points. NO2 is a toxic gas, which is identifiable by its yellow color. In this paper the conditions leading to increased NO2 formation have been investigated using a batch reactor model in Cantera. In a first step, it has been found that the high emission levels of NO2 can be traced back to the mixing of small amounts of quenched CH4 with NO from the hot combustion zones followed by post-oxidation in the presence of O2, requiring that the temperatures are within a certain range. In the second step, NO2 formation in the exhaust duct of a test engine has been modeled and compared to the experimental results. For that purpose a well-stirred reactor model has been used that calculates the steady-state of a uniform composition for a certain residence time. An appropriate reaction mechanism that considers the effect of NO/NO2 on methane oxidation at low temperature levels has been used. The numerical results of NO to NO2 conversion in the duct at low temperature and pressure levels show good agreement with the experimental results for various temperatures and concentrations of unburned methane. The partial oxidation of CH4 can be predicted well. It can be shown that methane oxidation in the presence of NO/NO2 at low temperature levels is enhanced via the reaction steps CH3 + NO2 ⇌ CH3O + NO and CH3O2 + NO ⇌ CH3O + NO2. In addition the elementary reaction HO2 + NO ⇌ NO2 + OH is the important NO oxidizing step.

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3D-printed Monolithic Catalyst of Mn-Ce-Fe/Attapulgite for Selective Catalytic Reduction of Nitric Oxide with Ammonia at Low Temperature

Journal of Environmental Chemical Engineering ◽

10.1016/j.jece.2021.105753 ◽

2021 ◽

pp. 105753

Author(s):

Yanqin Li ◽

Pan Jiang ◽

Junqi Tian ◽

Ying Liu ◽

Yinji Wan ◽

...

Keyword(s):

Nitric Oxide ◽

Low Temperature ◽

Selective Catalytic Reduction ◽

Catalytic Reduction ◽

Monolithic Catalyst ◽

3D Printed

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Additive Manufacturing of Electronics from Silver Nanopowders Sintered on 3D Printed Low‐Temperature Substrates.

Advanced Engineering Materials ◽

10.1002/adem.202001085 ◽

2021 ◽

pp. 2001085

Author(s):

Bartłomiej Wałpuski ◽

Marcin Słoma

Keyword(s):

Additive Manufacturing ◽

Low Temperature ◽

3D Printed

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CFD Study and Experimental Validation of a Dual Fuel Engine: Effect of Engine Speed

Energies ◽

10.3390/en14144307 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4307

Author(s):

Roberta De Robbio ◽

Maria Cristina Cameretti ◽

Ezio Mancaruso ◽

Raffaele Tuccillo ◽

Bianca Maria Vaglieco

Keyword(s):

Natural Gas ◽

High Performance ◽

Engine Speed ◽

Pollutant Emissions ◽

Dual Fuel ◽

Automotive Market ◽

Light Duty ◽

Viable Solution ◽

Dual Fuel Engines ◽

Gas Ratio

Dual fuel engines induce benefits in terms of pollutant emissions of PM and NOx together with carbon dioxide reduction and being powered by natural gas (mainly methane) characterized by a low C/H ratio. Therefore, using natural gas (NG) in diesel engines can be a viable solution to reevaluate this type of engine and to prevent its disappearance from the automotive market, as it is a well-established technology in both energy and transportation fields. It is characterized by high performance and reliability. Nevertheless, further improvements are needed in terms of the optimization of combustion development, a more efficient oxidation, and a more efficient exploitation of gaseous fuel energy. To this aim, in this work, a CFD numerical methodology is described to simulate the processes that characterize combustion in a light-duty diesel engine in dual fuel mode by analyzing the effects of the changes in engine speed on the interaction between fluid-dynamics and chemistry as well as when the diesel/natural gas ratio changes at constant injected diesel amount. With the aid of experimental data obtained at the engine test bench on an optically accessible research engine, models of a 3D code, i.e., KIVA-3V, were validated. The ability to view images of OH distribution inside the cylinder allowed us to better model the complex combustion phenomenon of two fuels with very different burning characteristics. The numerical results also defined the importance of this free radical that characterizes the areas with the greatest combustion activity.

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