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

2014 ◽  
Vol 48 (4) ◽  
pp. 2361-2367 ◽  
Author(s):  
I. Lefort ◽  
J. M. Herreros ◽  
A. Tsolakis
Keyword(s):  
Low Temperature ◽  
Species Interactions ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Diesel Oxidation

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

2007 ◽  
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 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.

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

2019 ◽  
Vol 245 ◽  
pp. 623-634 ◽  
Author(s):  
Wenxiang Tang ◽  
Xingxu Lu ◽  
Fangyuan Liu ◽  
Shoucheng Du ◽  
Junfei Weng ◽  
...  
Keyword(s):  
Low Temperature ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Diesel Oxidation

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

2008 ◽  
Vol 130 (4) ◽  
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.

Development of a Low Emissions Upgrade Kit for EMD GP20D and GP15D Locomotives

2012 ◽  
Author(s):  
Steven G. Fritz ◽  
John C. Hedrick ◽  
Tom Weidemann
Keyword(s):  
Fuel Injection ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Particulate Filter ◽  
Injection Timing ◽  
Fuel Injection Timing ◽  
Tier 1 ◽  
Emission Regulations ◽  
Diesel Oxidation ◽  
Tier 3

This paper describes the development of a low emissions upgrade kit for EMD GP20D and GP15D locomotives. These locomotives were originally manufactured in 2001, and met EPA Tier 1 locomotive emission regulations. The 1,491 kW (2,000 HP) EMD GP20D locomotives are powered by Caterpillar 3516B engines, and the 1,119 kW (1,500 HP) EMD GP15D locomotives are powered by Caterpillar 3512B engines. CIT Rail owns a fleet of 50 of these locomotives that are approaching their mid-life before first overhaul. Baseline exhaust emissions testing was followed by a low emissions retrofit development focusing on fuel injection timing, crankcase ventilation filtration, and application of a diesel oxidation catalyst (DOC), and then later a diesel particulate filter (DPF). The result was a EPA Tier 0+ certification of the low emissions upgrade kit, with emission levels below EPA Line-Haul Tier 3 NOx, and Tier 4 HC, CO, and PM levels.

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