Low Temperature Hydrocarbon Oxidation Diesel Oxidation Catalyst (DOC) with Improved Particulate Matter Oxidation Capability

Although low-temperature premixed compression ignition (PCI) combustion in a light-duty diesel engine offers dramatic and simultaneous reductions in nitric oxides (NOx) and soot, associated increases in unburned hydrocarbons (HC) and carbon monoxide (CO) become unacceptable. Production diesel oxidation catalysts (DOCs) are effective in oxidizing the increased levels of HC and CO under lean combustion conditions. However, the low temperature / high CO combination under rich PCI conditions, designed as a lean NOx trap (LNT) regeneration mode, generally renders the DOC ineffective. The objectives of this study are to characterize the oxidizing efficiency of a production DOC under lean and rich PCI conditions, and attempt to identify probable causes for the observed ineffectiveness under rich PCI. The study uses several tests to characterize the behavior of the DOC under lean PCI and rich PCI combustion conditions, including: (1) steady-state feed gas characterization, (2) transient feed gas characterization, (3) air injection (4) insulated AF sweep, and (5) combustion mode switching. The DOC never becomes effective under rich PCI for any of the tests, suggesting that the platinum-based catalyst may be incorrect for use with rich PCI. Furthermore, combustion mode switching between lean PCI and rich PCI (mimicking LNT loading and regeneration) demonstrates diminishing effectiveness of the DOC during and after continuous mode transitioning.

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Development of a Kalman filter estimator for simulation and control of particulate matter distribution of a diesel catalyzed particulate filter

International Journal of Engine Research ◽

10.1177/1468087418785855 ◽

2018 ◽

Vol 21 (5) ◽

pp. 866-884 ◽

Cited By ~ 1

Author(s):

Boopathi Singalandapuram Mahadevan ◽

John H Johnson ◽

Mahdi Shahbakhti

Keyword(s):

Particulate Matter ◽

Pressure Drop ◽

Mass Distribution ◽

Diesel Oxidation Catalyst ◽

Oxidation Catalyst ◽

Particulate Filter ◽

Filter Model ◽

Reduced Order ◽

Diesel Oxidation ◽

Catalyzed Particulate Filter

The knowledge of the temperature and particulate matter mass distribution is essential for monitoring the performance and durability of a catalyzed particulate filter. A catalyzed particulate filter model was developed, and it showed capability to accurately predict temperature and particulate matter mass distribution and pressure drop across the catalyzed particulate filter. However, the high-fidelity model is computationally demanding. Therefore, a reduced order multi-zone particulate filter model was developed to reduce computational complexity with an acceptable level of accuracy. In order to develop a reduced order model, a parametric study was carried out to determine the number of zones necessary for aftertreatment control applications. The catalyzed particulate filter model was further reduced by carrying out a sensitivity study of the selected model assumptions. The reduced order multi-zone particulate filter model with 5 × 5 zones was selected to develop a catalyzed particulate filter state estimator considering its computational time and accuracy. Next, a Kalman filter–based catalyzed particulate filter estimator was developed to estimate unknown states of the catalyzed particulate filter such as temperature and particulate matter mass distribution and pressure drop (Δ P) using the sensor inputs to the engine electronic control unit and the reduced order multi-zone particulate filter model. A diesel oxidation catalyst estimator was also integrated with the catalyzed particulate filter estimator in order to provide estimates of diesel oxidation catalyst outlet concentrations of NO2 and hydrocarbons and inlet temperature for the catalyzed particulate filter estimator. The combined diesel oxidation catalyst–catalyzed particulate filter estimator was validated for an active regeneration experiment. The validation results for catalyzed particulate filter temperature distribution showed that the root mean square temperature error by using the diesel oxidation catalyst–catalyzed particulate filter estimator is within 3.2 °C compared to the experimental data. Similarly, the Δ P estimator closely simulated the measured total Δ P and the estimated cake pressure drop error is within 0.2 kPa compared to the high-fidelity catalyzed particulate filter model.

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Ceria-based nanoflake arrays integrated on 3D cordierite honeycombs for efficient low-temperature diesel oxidation catalyst

Applied Catalysis B Environmental ◽

10.1016/j.apcatb.2019.01.028 ◽

2019 ◽

Vol 245 ◽

pp. 623-634 ◽

Cited By ~ 8

Author(s):

Wenxiang Tang ◽

Xingxu Lu ◽

Fangyuan Liu ◽

Shoucheng Du ◽

Junfei Weng ◽

...

Keyword(s):

Low Temperature ◽

Diesel Oxidation Catalyst ◽

Oxidation Catalyst ◽

Diesel Oxidation

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Reduction of Low Temperature Engine Pollutants by Understanding the Exhaust Species Interactions in a Diesel Oxidation Catalyst

Environmental Science & Technology ◽

10.1021/es4051499 ◽

2014 ◽

Vol 48 (4) ◽

pp. 2361-2367 ◽

Cited By ~ 17

Author(s):

I. Lefort ◽

J. M. Herreros ◽

A. Tsolakis

Keyword(s):

Low Temperature ◽

Species Interactions ◽

Diesel Oxidation Catalyst ◽

Oxidation Catalyst ◽

Diesel Oxidation

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Characteristic Response of a Production Diesel Oxidation Catalyst Exposed to Lean and Rich PCI Exhaust

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2906174 ◽

2008 ◽

Vol 130 (4) ◽

Cited By ~ 3

Author(s):

Timothy J. Jacobs ◽

Dennis N. Assanis

Keyword(s):

Low Temperature ◽

Diesel Oxidation Catalyst ◽

Oxidation Catalyst ◽

Mode Switching ◽

Lean Nox Trap ◽

Nitric Oxides ◽

Combustion Mode ◽

Lean Combustion ◽

Diesel Oxidation Catalysts ◽

Diesel Oxidation

Although low-temperature premixed compression ignition (PCI) combustion in a light-duty diesel engine offers dramatic and simultaneous reductions in nitric oxides (NOx) and soot, associated increases in unburned hydrocarbons (HC) and carbon monoxide (CO) become unacceptable. Production diesel oxidation catalysts (DOCs) are effective in oxidizing the increased levels of HC and CO under lean combustion conditions. However, the low-temperature∕high CO combination under rich PCI conditions, designed as a lean NOx trap (LNT) regeneration mode, generally renders the DOC ineffective. The objectives of this study are to characterize the oxidizing efficiency of a production DOC under lean and rich PCI conditions, and attempt to identify probable causes for the observed ineffectiveness under rich PCI. The study uses several tests to characterize the behavior of the DOC under lean PCI and rich PCI combustion conditions, including (1) steady-state feed gas characterization, (2) transient feed gas characterization, (3) air injection (4) insulated air-fuel sweep, and (5) combustion mode switching. The DOC never becomes effective under rich PCI for any of the tests, suggesting that the platinum-based catalyst may be incorrect for use with rich PCI. Furthermore, combustion mode switching between lean PCI and rich PCI (mimicking LNT loading and regeneration) demonstrates diminishing effectiveness of the DOC during and after continuous mode transitioning.

Download Full-text