Evaluation of Diesel Oxidation Catalyst Conversion of Hydrocarbons and Particulate Matter from Premixed Low Temperature Combustion of Biodiesel

2011 ◽  
Vol 4 (1) ◽  
pp. 1431-1444 ◽  
Author(s):  
William F. Northrop ◽  
Dennis N. Assanis ◽  
Stani Bohac
Keyword(s):  
Particulate Matter ◽  
Low Temperature ◽  
Diesel Oxidation Catalyst ◽  
Oxidation Catalyst ◽  
Low Temperature Combustion ◽  
Diesel Oxidation ◽  
Temperature Combustion ◽  
Premixed Low Temperature Combustion

scholarly journals Simultaneous particulate matter and nitrogen oxide emission reduction through enhanced charge homogenization in diesel engines

2018 ◽  
Vol 22 (5) ◽  
pp. 2039-2052 ◽  
Author(s):  
Urban Zvar-Baskovic ◽  
Rok Vihar ◽  
Samuel Rodman-Opresnik ◽  
Tomaz Katrasnik
Keyword(s):  
Particulate Matter ◽  
Low Temperature ◽  
Diesel Fuel ◽  
Minor Effect ◽  
Exhaust Gas ◽  
Low Temperature Combustion ◽  
Engine Control ◽  
Pyrolysis Oil ◽  
Trade Off ◽  
Temperature Combustion

In the presented study, low temperature combustion was established with a direct injection of diesel fuel being a representative of high reactivity fuels and tire pyrolysis oil being a representative of low reactivity fuels. Tire pyrolysis oil was tested as a potential waste derived fuel for low temperature combustion, as it features diesel-like physical properties and lower cetane number compared to diesel fuel. The goal of this study was determination of suitable injection strategies and exhaust gas re-circulation rates to explore potentials of both fuels in reducing emissions in low temperature combustion modes. It was demonstrated that relatively small changes in the engine control strategy possess the potential to significantly improve NOx/particulate matter trade-off with minor effect on engine efficiency. In addition, low temperature combustion was for the first time successfully demonstrated with tire pyrolysis oil fuel, however, it was shown that lower re-activity of the fuel is by itself not sufficient to improve NOx /soot trade-off compared to the diesel fuel as entire spectra of fuel properties play an important role in improving NOx /soot trade-off. This study thus establishes relations between different engine control strategies, intake manifold pressure and exhaust gas recirculation rate on engine thermodynamic parameters and engine-out emissions while utilizing innovative waste derived fuel that have not yet been analysed in similar combustion concepts.

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.

Comparison of Filter Smoke Number and Elemental Carbon Mass From Partially Premixed Low Temperature Combustion in a Direct-Injection Diesel Engine

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
William F. Northrop ◽  
Stanislav V. Bohac ◽  
Jo-Yu Chin ◽  
Dennis N. Assanis
Keyword(s):  
Diesel Engine ◽  
Low Temperature ◽  
Elemental Carbon ◽  
Direct Injection ◽  
Low Temperature Combustion ◽  
Soot Mass ◽  
Temperature Combustion ◽  
Carbon Mass ◽  
Partially Premixed ◽  
Premixed Low Temperature Combustion

Partially premixed low temperature combustion (LTC) is an established advanced engine strategy that enables the simultaneous reduction of soot and NOx emissions in diesel engines. Measuring extremely low levels of soot emissions achievable with LTC modes using a filter smoke meter requires large sample volumes and repeated measurements to achieve the desired data precision and accuracy. Even taking such measures, doubt exists as to whether filter smoke number (FSN) accurately represents the actual smoke emissions emitted from such low soot conditions. The use of alternative fuels such as biodiesel also compounds efforts to accurately report soot emissions since the reflectivity of high levels of organic matter found on the particulate matter collected may result in erroneous readings from the optical detector. Using FSN, it is desired to report mass emissions of soot using empirical correlations derived for use with petroleum diesel fuels and conventional modes of combustion. The work presented in this paper compares the experimental results of well known formulas for calculating the mass of soot using FSN and the elemental carbon mass using thermal optical analysis (TOA) over a range of operating conditions and fuels from a four-cylinder direct-injection passenger car diesel engine. The data show that the mass of soot emitted by the engine can be accurately predicted with the smoke meter method utilizing a 3000 ml sample volume over a range of FSN from 0.02 to 1.5. Soot mass exhaust concentration calculated from FSN using the best of the literature expressions and that from TOA taken over all conditions correlated linearly with a slope of 0.99 and R2 value of 0.94. A primary implication of the work is that the level of confidence in reporting the soot mass based on FSN for low soot formation regimes such as LTC is improved for both petroleum diesel and biodiesel fuels.

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