This study investigates the effects of biogas composition on combustion stability for a purely biogas fueled homogeneous charge compression ignition (HCCI) engine. Biogas is one of the most promising renewable fuels for combined heat and power systems driven by internal combustion engines. However, the high content of CO2 in biogas composition leads to low thermal efficiencies in spark ignited and dual fuel compression ignited engines. The study is divided into two parts: First experimental results on a biogas-fueled HCCI engine are used to illustrate the effects of intake conditions on combustion stability, and second a simulation methodology is used to investigate how biogas composition impacts combustion stability at constant intake conditions. Experimental analysis of a four cylinder, 1.9 L Volkswagen TDI diesel engine shows that biogas-HCCI combustion exhibits high gross indicated mean effective pressure (close to 8 bar), high gross indicated efficiency (close to 45%), and ultralow NOx emissions below the US2010 limit (0.27 g/kWh). An inlet absolute pressure of 2 bar and inlet temperature of 473 K (200 °C) were required for allowing HCCI combustion with a biogas composition of 60% CH4 and 40% CO2 on a volumetric basis. However, slight changes in inlet pressure and temperature caused large changes in cycle-to-cycle variations at low equivalence ratios and large changes in ringing intensity at high equivalence ratios. Numerical analysis of biogas-HCCI combustion is carried out with a sequential methodology that includes one-zone model simulations, computational fluid dynamics (CFD) analysis, and 12-zones model simulations. Numerical results for varied biogas composition show that at high load limit, higher contents of CH4 in biogas composition allow advanced combustion and increased burning rates of the biogas air mixture. Higher contents of CO2 in biogas composition allow lowered ringing intensities with moderate decrease in the indicated efficiency and power output. NOx emissions are not highly affected by biogas composition, while CO and unburned hydrocarbons (HC) emissions tend to increase with higher contents of CO2. According with the numerical results, biogas composition is an effective strategy to control the onset of combustion and combustion phasing of HCCI engines running biogas, allowing more stabilized combustion at low equivalence ratios and safe operation at high equivalence ratios. The main advantages of using biogas-fueled HCCI engines in CHP systems are the low sensitivity of power output and indicated efficiency to biogas composition, as well as the ultralow NOx emissions achieved for all tested compositions.

References

References
1.
Holm-Nielsen
,
J. B.
, and
Oleskowicz-Popiel
P.
,
2007
, “
The Future of Biogas in Europe: Visions and Targets Until 2020
,”
Proceedings of the European Biogas Workshop–Intelligent Energy Europe
,
Esbjerg, Denmark
, June 14–16.
2.
US-EPA
,
2010
, “
Market Opportunities for Biogas Recovery Systems
,” accessed November 2011, www.epa.gov/agstar/tools/market-oppt.html
3.
Deublein
,
D.
, and
Steinhauser
A.
,
2008
,
Biogas From Waste and Renewable Resources. An Introduction
,
Wiley-VCH Verlag GmbH & Co. KGaA
,
Weinheim, Germany
.
4.
Pöschl
,
M.
,
Ward
,
S.
, and
Owende
P.
,
2010
, “
Evaluation of Energy Efficiency of Various Biogas Production and Utilization Pathways
,”
Appl. Energy
,
87
, pp.
3305
3321
.10.1016/j.apenergy.2010.05.011
5.
Richter
,
M.
,
Franke
,
A.
,
Alden
,
M.
,
Hultqvist
,
A.
, and
Johansson
B.
,
1999
, “
Optical Diagnostics Applied to a Naturally Aspirated Homogeneous Charge Compression Ignition Engine
,”
SAE
Paper 1999-01-3649.10.4271/1999-01-3649
6.
Hultqvist
,
A.
,
Christensen
,
M.
,
Johansson
,
B.
,
Franke
,
A.
,
Richter
,
M.
, and
Aldén
M.
,
1999
, “
A Study of the Homogeneous Charge Compression Ignition Combustion Process by Chemiluminescence Imaging
,”
SAE
Paper 1999-01-3680.10.4271/1999-01-3680
7.
Christensen
,
M.
, and
Johansson
B.
,
1999
, “
Homogeneous Charge Compression Ignition With Water Injection
,”
SAE
Paper 1999-01-0182.10.4271/1999-01-0182
8.
Markel
D. B.
,
2007
,
Land Fill Gas Fuelled HCCI Demonstration System
, Technical Report No. CEC-500-2007-078, California Energy Commission, Chico, CA.
9.
Nathan
,
S. S.
,
Mallikarjuna
,
J. M.
, and
Ramesh
A.
,
2010
, “
An Experimental Study of the Biogas–Diesel HCCI Mode of Engine Operation
,”
Energy Conver. Manage.
,
51
, pp.
1347
1353
.10.1016/j.enconman.2009.09.008
10.
Nathan
,
S. S.
,
Mallikrajuna
,
J. M.
, and
Ramesh
A.
,
2009
, “
Homogeneous Charge Compression Ignition Versus Dual Fuelling for Utilizing Biogas in Compression Ignition Engines
,”
Proc. IMechE DJ. Auto. Eng.
,
223
, pp.
413
422
.10.1243/09544070JAUTO970
11.
Bedoya
,
I. D.
,
Saxena
,
S.
,
Cadavid
,
F. J.
,
Dibble
,
R. W.
, and
Wissink
M.
,
2012
, “
Experimental Study of Biogas Combustion in an HCCI Engine for Power Generation With High Indicated Efficiency and Ultra-Low NOx Emissions
,”
Energy Convers. Manage.
,
52
(
1
), pp.
154
162
.10.1016/j.enconman.2011.08.016
12.
Bedoya
,
I. D.
,
Saxena
,
S.
,
Cadavid
,
F. J.
,
Dibble
,
R. W.
, and
Wissink
M.
,
2012
, “
Experimental Evaluation of Strategies to Increase the Operating Range of a Biogas-Fueled HCCI Engine for Power Generation
,”
Appl. Energy
,
97
, pp.
618
629
.10.1016/j.apenergy.2012.01.008
13.
Bedoya
,
I. D.
,
Saxena
,
S.
,
Dibble
,
R. W.
, and
Cadavid
F. J.
,
2011
, “
Exploring Optimal Operating Conditions for Stationary Power Generation From a Biogas-Fueled HCCI Engine
,”
7th U.S. National Technical Meeting of the Combustion Institute, Georgia Institute of Technology
,
Atlanta, GA
, March 20–23, pp.
2172
2177
.
14.
Bedoya
,
I. D.
,
Saxena
,
S.
,
Cadavid
,
F. J.
,
Dibble
,
R. W.
, and
Wissink
M.
,
2011
, “
Experimental Evaluation of Strategies to Increase the Operation Range of a Biogas HCCI Engine for Power Generation
,”
Third International Conference on Applied Energy (ICAE 2011)
,
Perugia, Italy
, May 16–18, pp.
2219
2244
.
15.
Easley
,
W. L.
,
Agarwal
,
A.
, and
Lavoie
G. A.
,
2001
, “
Modeling of HCCI Combustion and Emissions Using Detailed Chemistry
,”
SAE
Paper 2001-01-1029.10.4271/2001-01-1029
16.
Jun
,
D.
,
Ishii
,
K.
, and
Iida
N.
,
2003
, “
Autoignition and Combustion of Natural Gas in a 4 Stroke HCCI Engine
,”
JSME Int. J.
,
46
(
1
), pp.
60
67
.10.1299/jsmeb.46.60
17.
Kobayashi
,
H.
,
Hagiwara
,
H.
,
Kaneko
,
H.
, and
Ogami
Y.
,
2007
, “
Effects of CO2 Dilution on Turbulent Premixed Flames at High Pressure and High Temperature
,”
Proc. Combust. Inst.
,
31
(
1
), pp.
1451
1458
.10.1016/j.proci.2006.07.159
18.
Eng
J. A.
,
2002
, “
Characterization of Pressure Waves in HCCI Combustion
,”
SAE
Paper 2002-01-2859.10.4271/2002-01-2859
19.
Sjöberg
,
M.
,
Dec
,
J. E.
,
Babajimopoulos
,
A.
, and
Assanis
D.
,
2004
, “
Comparing Enhanced Natural Thermal Stratification Against Retarded Combustion Phasing for Smoothing of HCCI Heat-Release Rates
,”
SAE
Paper 2004-01-2994.10.4271/2004-01-2994
20.
Shahbakhti
,
M.
, and
Koch
C. R.
,
2008
, “
Characterizing the Cyclic Variability of Ignition Timing in a Homogeneous Charge Compression Ignition Engine Fuelled With n-heptane/Iso-Octane Blend Fuels
,”
Int. J. Engine Res.
,
9
, pp.
361
397
.10.1243/14680874JER01408
21.
Xingcai
,
L.
,
Libin
,
J.
,
Junjun
,
M.
, and
Zhen
H.
,
2007
, “
Experimental Study on the Cycle-to-Cycle Variations of Homogeneous Charge Compression Ignition Combustion Using Primary Reference Fuels and Their Mixtures
,”
Proc. IMechE D J. Auto. Eng.
,
221
(
7
), pp.
859
866
.10.1243/09544070JAUTO481
22.
Bedoya
,
I. D.
,
Saxena
,
S.
,
Cadavid
,
F. J.
, and
Dibble
R. W.
,
2012
, “
Exploring Strategies for Reducing High Intake Temperature Requirements and Allowing Optimal Operational Conditions in a Biogas Fueled HCCI Engine for Power Generation
,”
ASME J. Eng. Gas Turb. Power
,
134
(
072806
), pp.
1
9
.10.1115/1.4006075
23.
Bedoya
,
I. D.
,
Cadavid
,
F. J.
,
Saxena
,
S.
,
Dibble
,
R. W.
,
Aceves
,
S.
, and
Flowers
D.
,
2012
, “
A Sequential Chemical Kinetics-CFD-Chemical Kinetics Methodology to Predict HCCI Combustion and Main Emissions
,”
SAE
Paper 2012-01-1119.10.4271/2012-01-1119
24.
Aceves
,
S. M.
,
Flowers
,
D. L.
,
Joel
Martinez-Frias
,
Smith
,
J. R.
,
Westbrook
,
C. K.
,
Pitz
,
W. J.
,
Dibble
,
R.
,
Wright
,
J. F.
,
Akinyemi
,
W. C.
, and
Hessel
R. P.
,
2001
, “
A Sequential Fluid-Mechanic Chemical-Kinetic Model of Propane HCCI Combustion
,”
SAE
Paper 2001-01-1027.10.4271/2001-01-1027
You do not currently have access to this content.