Biomass Fuel Applications in IC Engines

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1 The Energy Institute Biomass Fuel Applications in IC Engines André Boehman Professor of of Fuel Fuel Science and and Materials Science and and Engineering Department of of Energy and and Mineral Engineering The The Penn State Energy Institute College of of Earth and and Mineral Sciences The The Pennsylvania State University

2 The Energy Institute Topics Covered Biodiesel Some Some observations of of biodiesel biodiesel combustion in in a Cummins Cummins ISB ISB 5.9L 5.9L MY2000 MY2000 turbodiesel engine engine Sources Sources of of the the Biodiesel Biodiesel NOx NOx effect effect Fuel Fuel quaity quaityissues issues Impact Impact on on soot soot characteristics Renewable Diesel Ethanol Process Process relies relies on on existing existing refinery refinery technology Yields Yields a fuel fuel that that looks looks like like synthetic synthetic diesel diesel that that creates creates none noneof of the the fuel fuel quality quality concerns concerns associated associated with with biodiesel biodiesel Efficiency Efficiency and and performance issues issues Certification of of E85 E85 pumps pumps

3 Research Strategy The Energy Institute Feedstock Fuel Production Fuel Properties Feedback of Behavior and Performance Information Fuel Properties Injection Characteristics Spray Visualization Chamber Bulk Modulus of Compressibility Combustion Pollutant Formation AVL 513D Engine Videoscope Particulate and Gaseous Emissions Particulate Filtration DPF Regeneration NOx Reduction Various Aftertreatment Strategies

4 The Energy Institute How Biodiesel Affects Combustion Physical Property Differences Relative to to No. No. 2 Diesel Fuels Density, Density, Viscosity, Viscosity, Latent Latent Heat Heat of of Vaporization and and the the Bulk Bulk Modulus Modulus of of Compressibility are are Higher Higher Greater Greater momentum momentum in in the the spray, spray, deeper deeper spray spray penetration, penetration, larger larger interaction interaction with with air air mass mass during during vaporization vaporization Shifts Shifts in in injection injection timing timing due due to to more more rapid rapid force force transfer transfer from from the the fuel fuel pump pump to to the the fuel fuel injector injector (not (not an an issue issue in in common common rail rail fuel fuel injection injection systems) systems) Chemical Property Differences Relative to to No. No. 2 Diesel Fuels Calorific Calorific Value Value and and Sooting SootingTendency are are Lower Lower Requires Requires greater greater rate rate of of injection injection (higher (higher rail rail pressure) pressure) or or extended extended duration duration of of injection injection Lowers Lowers the the soot soot volume volume fraction fraction within within the the spray spray flame flame and and lowers lowers the the dry dry soot soot fraction fraction of of the the particulate particulate matter matter C. Westbrook

5 Spray and Combustion The Energy Institute 10% Load and 1800 RPM in in Cummins 5.9L ISB BP 15 BP % Biodiesel B100

6 Kinetics and Decomposition Models for Biodiesel The Energy Institute Heat Release (kj/deg) Heat Release (kj/deg) Compression Ratio = LTHR TDC Crank Angle Compression Ratio = HTHR LTHR TDC Crank Angle Heat release and temperature traces for methyl decanoate for (a) LTHR only, and (b) LTHR and HTHR. (a) (b) Note: methyl butanoate and dibutyl maleate have been used by Westbrook and co-workers as surrogates for biodiesel (esters); DOE is interested in kinetics for modeling of alternative fuels Temperature (K) Temperature (K) Carbon Dioxide and Carbon Monoxide (%) Carbon Dioxide and Carbon Monoxide (%) Compression Ratio (a)n-heptane, Φ= Compression Ratio (b) methyl decanoate, Φ=0.25 Formaldehyde and Acetaldehyde (ppm) Formaldehyde and Acetaldehyde (ppm)

7 The Energy Institute Tat and Van Gerpen, NREL/SR Biodiesel NOx NOxEffect Comes from from Advanced Injection Timing Advance Advance in in injection injection timing timing comes comes from from more more rapid rapid pressure pressure build buildup up and and force force transfer transfer to to the the needle needle valve valve Due Due to to both both higher higher viscosity viscosity of of biodiesel biodiesel and and higher higher bulk bulk modulus modulus of of compressibility 2-4% 2-4% increase increase with with B20, B20, 10% 10% increase increase with with B100, B100, might might not not occur occur at atlight loads loads

8 NOx emissions as a function of the timing of the maximum cylinder temperature ( ) BP325, ( ) B20, ( ) B40, ( ) B100, ( ) FT20, ( ) FT40, and ( ) FT100. NOx Emissions of Alternative Diesel Fuels: A Comparative Analysis of Biodiesel and FT Diesel, Energy & Fuels, 2005 Brake Specific NOx Emissions (g/kw-h) Brake Specific NOx Emissions (g/kw-h) The Energy Institute Timing of Maximum Temperature (CA) Timing of Maximum Temperature (CA) (a) high load 3600 RPM and 75% of max output (b) low load 3600 RPM and 25% of max output

9 The Energy Institute NOx Effect in Common Rail Engines Higher NOx due to reduced radiative heat transfer, and therefore higher flame temperature Cheng et al., 2006

10 Effects of Biodiesel under Single Injection, High Load condition Apparent Heat Release Rate (J/Deg) Brake Specific Fuel Consumption (g/kw-h) Indicated SOI: 7 Deg BTDC CA (Deg) BP15 B20 B Indicated Injection Timing (Deg BTDC) BP15 B20 B40 Change in NOx Compared to BP15 (%) B20 B Indicated Injection Timing (Deg BTDC) At the baseline condition, B20 produced 2.3% more NO x and B40 produced 10.1% more NO x NO x emissions difference between biodiesel blends and BP15 increased as the injection timing was advanced No measurable injection timing difference observed between biodiesel blends and BP15 Biodiesel blends and BP15 had very similar heat release rate profiles A 2 CA delay in injection timing for B20 from the baseline condition yielded 6.6% NO x emissions reduction with 3.3% increase in fuel consumption compared to the baseline BP15

11 Effects of Biodiesel under Single Injection, Low Load condition 6 5 BP15 B20 B BP15 B20 B40 BSNOx (g/kw-h) BSFC (g/kw-h) Indicated Injection Timing (Deg BTDC) Indicated Injection Timing (Deg BTDC) Apparent Heat Release Rate (J/Deg) Indicated SOI: 4 Deg BTDC BP15 B20 B CA (Deg) Biodiesel blends had slightly lower NO x emissions due to the lower heat of combustion and adiabatic flame temperature of biodiesel under the lean premixed low load condition Biodiesel blends had slightly earlier start of combustion and lower peak heat release rate than BP15

12 The Energy Institute Summary Biodiesel can affect injection timing, flame luminosity, spray penetration and mixing Depending on on fuel injection system configuration, the the Biodiesel NOx Effect may be be circumvented by by increasing cetane number and increasing fuel compressibility (or (or decreasing fuel density), or or by by modest shifts in in injection timing The growing body of of evidence shows that the the Biodiesel NOx Effect may be be restricted to to high load operation in in common rail rail engines, and that biodiesel may reduce NOx at at lower loads It It remains to to identify the the chief cause of of the the Biodiesel NOx Effect in in common rail rail engines

13 The Energy Institute J. Brown, Nat l Biodiesel Conf., 2006

14 The Energy Institute E. Lyford-Pike, Nat l Biodiesel Conf., 2006

15 The Energy Institute E. Lyford-Pike, Nat l Biodiesel Conf., 2006

16 The Energy Institute Alleman and McCormick, 2007 National Biodiesel Conference

17 The Energy Institute Williams, 2007 National Biodiesel Conference

18 The Energy Institute Summary and Status of Biodiesel Explosive growth of of interest Uncertain future growth potential Corn prices doubled since the the 2006 State of of Union Address emphasizing ethanol production Soybean prices are are increasing in in response to to biodiesel demand Quality control problems 50% of of biodiesel sold in in 2006 may not not have met the the fuel quality specifications Other technologies, such as as Renewable Diesel may undercut biodiesel as as it it expands because they do do not not suffer the the oxidative stability and contamination problems of of biodiesel and are are fungible and look like other hydrocarbons within a refinery New initiative on on Second Generation Biodiesel getting underway to to improve feedstock chemistry to to make better biodiesel

19 The Energy Institute Biodiesel and Emission Control Fuel Effects on Soot and DPF Regeneration

20 The Energy Institute NO 2 produced (ppm) Equilibrium NO 2 BP325B20 BP Pressure Drop (mbar) Time (min) Requires Requires periodic periodic burn-off burn-off of of the the filtered filtered diesel diesel particulates to to prevent prevent excessive excessive backpressure wall flow filtration Diesel Particulate Filters are required as of 2007

21 Enhanced DPF Regeneration with Biodiesel Lower Required Regeneration Temperature More Reactive Primary Soot Particles See Energy & Fuels, 19, (2005) and Combustion & Flame, 146, (2006) Normalized Pressure drop Time (min) 100 BP15 B20 B100 FT 120 High Temperature Regeneration Test (a) BP15 Derived PM (b) BP15B20 Derived PM The Energy Institute

22 The Energy Institute B100 Soot 105k x 500k x 800k x 75% burn off, 50 min 100 nm

23 Renewable Diesel The Energy Institute

24 Renewable Diesel Fuel Competing with Biodiesel? The Energy Institute Produced by by catalytic thermal depolymerization of of animal fats and vegetable oil oil Commercial process used by by Neste Oil Oil (Finland) and ConocoPhillips April 16, 16, 2007 press release announces a strategic alliance between ConocoPhillips and Tyson Foods chicken fat fat to to diesel fuel Seamless production of of diesel fuel from a renewable source Yields C 16 alkanes 16 (hydrocarbons) Looks like the the rest of of the the refinery streams but but has no no sulfur or or aromatics Qualified for for $1/gallon tax tax credit Conflict with the the National Biodiesel Board over the the tax tax credit and what is is covered by by the the federal legislation

25 Clark et al., DOE Fuels Merit Review, 2007 The Energy Institute

26 Clark et al., DOE Fuels Merit Review, 2007 The Energy Institute

27 The Energy Institute Ethanol Efficiency and Delivery

28 West, DOE Fuels Merit Review, 2007 The Energy Institute

29 West, DOE Fuels Merit Review, 2007 The Energy Institute

30 West, DOE Fuels Merit Review, 2007 The Energy Institute

31 The Energy Institute Demonstrated a 3-6% efficiency improvement just by going to lean burn West, DOE Fuels Merit Review, 2007

32 Clark, DOE Fuels Merit Review, 2007 The Energy Institute

33 Clark, DOE Fuels Merit Review, 2007 The Energy Institute

34 Roj, Future Fuels, 2006 The Energy Institute

35 Summary and Questions The Energy Institute Biodiesel Biodiesel NOx NOxEffect, Soot Soot Impact Impact and and Biodiesel Biodiesel Properties Properties What What controls controls the the NOx NOxeffect in in common common rail rail engines? engines? Determining how how to to use use fuel fuel and and combustion conditions conditions to to enhance enhancereactivity of of diesel diesel soot soot to to reduce reduce the the fuel fuel economy economy burden burden and and system system complexity complexity for for DPFs DPFs can can we we eliminate eliminate the the need need for for active active control? control? Need Need information to to guide guide the the genetic genetic engineering of of plants plants to to improve improve biofuel biofuel performance: How How does does FAME FAME composition affect affect sooting sootingin in flames? flames? Renewable Renewable Diesel Diesel Will Will conflict conflict over over the the blenders blenders tax tax credit credit turn turn into into a roadblock roadblock for for this this technology? Ethanol Ethanol Large Large amount amount of of momentum Poor Poor efficiency efficiency of of production production using using existing existing corn corn fermentation Engine Engine optimization may may push push ethanol ethanol energy energy efficiency efficiency above above that that of of gasoline gasoline