A substantial opportunity exists to reduce carbon dioxide (CO2) emissions, as well as dependence on foreign oil, by developing strategies to cleanly and efficiently use biodiesel, a renewable domestically available alternative diesel fuel. However, biodiesel utilization presents several challenges, including decreased fuel energy density and increased emissions of smog-generating nitrogen oxides (NOx). These negative aspects can likely be mitigated via closed-loop combustion control provided the properties of the fuel blend can be estimated accurately, on-vehicle, in real-time. To this end, this paper presents a method to practically estimate the biodiesel content of fuel being used in a diesel engine during steady-state operation. The simple generalizable physically motivated estimation strategy presented utilizes information from a wideband oxygen sensor in the engine’s exhaust stream, coupled with knowledge of the air-fuel ratio, to estimate the biodiesel content of the fuel. Experimental validation was performed on a 2007 Cummins 6.7 l ISB series engine. Four fuel blends (0%, 20%, 50%, and 100% biodiesel) were tested at a wide variety of torque-speed conditions. The estimation strategy correctly estimated the biodiesel content of the four fuel blends to within 4.2% of the true biodiesel content. Blends of 0%, 20%, 50%, and 100% were estimated to be 2.5%, 17.1%, 54.2%, and 96.8%, respectively. The results indicate that the estimation strategy presented is capable of accurately estimating the biodiesel content in a diesel engine during steady-state engine operation. This method offers a practical alternative to in-the-fuel type sensors because wideband oxygen sensors are already in widespread production and are in place on some modern diesel vehicles today.

1.
United States Environmental Protection Agency
, 2002, “
A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions
,” Technical Report No. EPA420-P-02-001.
2.
Hill
,
J.
,
Nelson
,
E.
,
Tilman
,
D.
,
Polasky
,
S.
, and
Tiffany
,
D.
, 2006, “
Environmental, Economic, and Energetic Costs and Benefits of Biodiesel and Ethanol Biofuels
,”
Proc. Natl. Acad. Sci. U.S.A.
0027-8424,
103
(
30
), pp.
11206
11210
.
3.
Sheehan
,
J.
,
Camobreco
,
V.
,
Duffield
,
J.
,
Graboski
,
M.
, and
Shapouri
,
H.
, 1998, “
Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus
,” Technical Report No. NREL/SR-580-24089.
4.
Tat
,
M.
, 2003, “
Investigation of Oxides of Nitrogen Emissions From Biodiesel-Fueled Engines
,” Ph.D. thesis, Iowa State University.
5.
McCormick
,
R.
,
Tennant
,
C.
,
Hayes
,
R.
,
Black
,
S.
,
Ireland
,
J.
,
McDaniel
,
T.
,
Williams
,
A.
,
Frailey
,
M.
, and
Sharp
,
C.
, 2005, “
Regulated Emissions From Biodiesel Tested in Heavy-Duty Engines Meeting 2004 Emission Standards
,” SAE Paper No. 2005-01-2200.
6.
Wang
,
W.
,
Lyons
,
D.
,
Clark
,
N.
,
Gautam
,
M.
, and
Norton
,
P.
, 2000, “
Emissions From Nine Heavy Trucks Fueled by Diesel and Biodiesel Blend Without Modification
,”
Environ. Sci. Technol.
0013-936X,
34
, pp.
933
939
.
7.
Szybist
,
J.
,
Song
,
J.
,
Alam
,
M.
, and
Boehman
,
A.
, 2007, “
Biodiesel Combustion, Emissions, and Emission Control
,”
Fuel Process. Technol.
0378-3820,
88
, pp.
679
691
.
8.
Ban-Weiss
,
G.
,
Chen
,
J.
,
Buchholtz
,
B.
, and
Dibble
,
R.
, 2007, “
A Numerical Investigation Into the Anomalous Slight NOx Increase When Burning Biodiesel: A New (Old) Theory
,”
Fuel Process. Technol.
0378-3820,
88
, pp.
659
667
.
9.
McCormick
,
R.
,
Graboski
,
M.
,
Alleman
,
T.
,
Herring
,
A.
, and
Tyson
,
K.
, 2001, “
Impact of Biodiesel Source Material and Chemical Structure on Emissions of Criteria Pollutants From a Heavy-Duty Engine
,”
Environ. Sci. Technol.
0013-936X,
35
, pp.
1742
1747
.
10.
Eckerle
,
W.
,
Lyford-Pike
,
E.
,
Stanton
,
D.
,
LaPointe
,
L.
,
Whitacre
,
S.
, and
Wall
,
J.
, 2008, “
Effects of Methyl Ester Biodiesel Blends on NOx
Emissions,” SAE Paper No. 2008-01-0078.
11.
Tat
,
M.
, and
Van Gerpen
,
J.
, 2003, “
Measurement of Biodiesel Speed of Sound and Its Impact on Injection Timing
,” Technical Report No. NREL/SR-510-31462.
12.
Szybist
,
J.
,
Kirby
,
S.
, and
Boehman
,
A.
, 2005, “
NOx Emissions of Alternative Diesel Fuels: A Comparative Analysis of Biodiesel and FT Diesel
,”
Energy Fuels
0887-0624,
19
, pp.
1484
1492
.
13.
Postrioti
,
L.
,
Battistoni
,
M.
,
Grimaldi
,
C.
, and
Millo
,
F.
, 2003, “
Injection Strategies Tuning for the Use of Bio-Derived Fuels in a Common Rail HSDI Diesel Engine
,” SAE Paper No. 2003-01-0768.
14.
Agarwal
,
D.
,
Sinha
,
S.
, and
Agarwal
,
A.
, 2006, “
Experimental Investigation of Control of NOx Emissions in Biodiesel-Fueled Compression Ignition Engine
,”
Renewable Energy
0960-1481,
31
, pp.
2356
2369
.
15.
Basavaraja
,
T.
,
Reddy
,
R.
, and
Swamy
,
V.
, 2005, “
Effect of Injection Pressure on Emission Performance of Bio-Diesel and Its Blends
,” SAE Paper No. 2005-26-030.
16.
Tat
,
M.
, and
Van Gerpen
,
J.
, 2001, “
Biodiesel Blend Detection Using a Fuel Composition Sensor
,” ASAE Paper No. 016052.
17.
Knothe
,
G.
, 2001, “
Determining the Blend Level of Mixtures of Biodiesel With Conventional Diesel Fuel by Fiber-Optic Near Infrared Spectroscopy and H1 Nuclear Magnetic Resonance Spectroscopy
,”
Journal of the American Oil Chemists' Society
,
78
, pp.
1025
1028
. 0147-2011
18.
Zawadzki
,
A.
,
Shrestha
,
D.
, and
He
,
B.
, 2007, “
Biodiesel Blend Level Detection Using Absorption Spectra
,”
Trans. ASABE
0001-2351,
50
(
4
), pp.
1349
1353
.
19.
Robert Bosch Gmb
,
H.
, 2004,
Automotive Handbook
,
6th ed.
,
SAE
,
Warrendale, PA
.
20.
Heywood
,
J.
, 1988,
Internal Combustion Engine Fundamentals
,
McGraw-Hill
,
New York, NY
.
21.
Ackman
,
R.
, 1996, “
Fatty Acids in Newer Fats and Oils
,”
Bailey’s Industrial Oil and Fat Products
, Vol.
1
,
Y.
Hui
, ed.,
Wiley
,
New York, NY
, pp.
427
439
.
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