U.S. Naval Academy 410-293-6339 / [email protected] Current and Future Navy Challenges with Hydrocarbon Fuels

U.S. Naval Academy 410-293-6339 / Prak@Usna.Edu Current and Future Navy Challenges with Hydrocarbon Fuels

 Petroleum-based fuels sources around the world vary in properties • Need to constantly monitor fuel quality • Europe mixes biodiesel with diesel

 Conventional petroleum prices are currently low (< $50 / barrel) • Favorable situation for petroleum-based fuels • Alternative fuels: currently more expensive ‒ Environmental movement maintains interest ‒ Future costs may increase economic viability ‒ The composition of these fuels can be dramatically different than conventional fuels. These differences can lead to performance issues.

 NEEDED: Ability to predict properties and performance given knowledge of fuel composition

Image from https://en.wikipedia.org/wiki/World_map#/media/File:Winkel_triple_projection_SW.jpg http://www.cnbc.com/2015/10/25/oil-prices-drop-demand-seen-sagging-towards-year-end.html

2 Fuel Hydrocarbon Distribution

HRD-algae olefins HRJ-camelina CHC cyclo- Jet/Diesel DSH-sugars/biomass oils alkanes iso-alkanes HDCD-wood ATJ-sugars/biomass aromatics Reactivity (cetane) Reactivity

Number of Carbon Atoms

3 Goals of Neptune Funding

 Measurement of Chemical and Thermophysical Properties of Fuels and Organic Liquid Mixtures • Chemical composition, density, viscosity, surface tension, flash point, heat of combustion, distillation curve  Prediction of Thermophysical Properties through Atomistic Modeling • Develop a computer model for calculating thermophysical properties of fuels based on their chemical composition  Characterization of Diesel Engine Combustion • Evaluate Fuels and fuel blends of interest to the Navy • Study the effects of changing physical and chemical properties  Support the Navy Mission • Educate future Navy leaders in the Science and Engineering of Fuels • Support Navy and NAVAIR to help them respond to emerging Navy fuel needs NAVY IMPACT: Facilitate the “fit for purpose” determination of Navy fuels. Educate future Navy leaders. Support the Navy response to emerging fuel needs.

4 Synergy of the USNA Research Efforts

Jim Cowart Combustion Physical/Chemical Properties Len Hamilton Modeling Fuel Determination Development of Properties & of the impact model of properties composition on combustion Refinement Combustion behavior Pure & multi- & validation of fuels & component of mixtures data predictive models Preparation and measurement of properties of mixtures Dianne Luning Prak with known composition Dan O’Sullivan Judith Harrison Paul Trulove Mixture Development

Fuels & some fuel Navy Air Systems Andy McDaniel properties Command Terrence Dickerson

5 Physical and Chemical Analysis of Fuels

Gas Chromatograph / Analytical Methods Mass Spec (GC/MS) • Gas Chromatograph / 200 100 Mass Spec (GC/MS) for Fuel JP-5 fuel characterization Properties & • Density composition • Viscosity 100 0 • Speed of Sound ATJ-8

Dianne Luning Prak Relative Intensity • Surface Tension Dan O’Sullivan Paul Trulove 0 -100 • Heat of combustion 25811 • Bulk modulus Time (min)

Major components Alcohol-to-Jet fuel (ATJ-8) • 2,2,4,4,6,8,8- heptamethylnonane • 2,2,4,6,6-pentamethylheptane Fuel spray We= ρ v2 l / σ

6 Development of Surrogate Mixtures

Fuel Properties & composition

Preparation and measurement of properties of mixtures with known composition

Fuel Surrogate** Mixture Development

**Fuel Surrogates are mixtures of one or more simple fuels that are designed to emulate the physical properties/combustion properties of a more complex fuel.

7 Development of Surrogate Mixtures for Alcohol-to-Jet fuel (ATJ-8)

Determination of optimal mixture composition for ATJ-8 surrogate using measured properties Similar 790 behavior for

780 other properties -3

770 /kg∙m

760

density 750 ATJ fuel density 740 0 0.2 0.4 0.6 0.8 1

mole fraction of 2,2,4,4,6,8,8-heptamethylnonane in 2,2,4,6,6- pentamethylheptane

0.23 mole fraction of 2,2,4,4,6,8,8-heptamethylnonane in 2,2,4,6,6- pentamethylheptane mixture tested in combustion experiments 8 Combustion of Fuels and Surrogates using Various Military Engines

Jim Cowart Combustion Len Hamilton Fuel Determination of the impact Properties & of properties composition on combustion Combustion behavior of fuels & mixtures Preparation and measurement of properties of mixtures with known composition

Mixture Development

Fuels & some fuel Navy Air Systems Andy McDaniel properties Command Terrence Dickerson

9 Combustion of Fuels and Mixtures using Various Instrumented Engines

Jim Cowart Len Hamilton

Humvee Diesel

Yanmar Small Diesel Generator

Waukesha Cetane Cummins Diesel Test Engine (small boat propulsion) 10 New Fuel Combustion Acceptance Criteria Impact on Torque & Power Top Dead Center (TC) ±5 % ± 10%

Ignition Delay Ratio Injection

Peak Pressure Location Chamber Pressure Rate of Heat Release Ratio Acceptance criteria built upon Time comparison to key combustion properties of existing (base) fuel Cowart, J.S., Hamilton, L.J., Williams, S.A. and McDaniel, A., ‘Alternative Diesel Fuel Combustion Acceptance Criteria for New Fuels in Legacy Diesel Engines’, Society of Automotive Engineers’ International Congress, Detroit, MI, April 2013. 11 Combustion of Fuels & Mixtures: Analysis of Engine RPM & Centane Number

4000 Derived Cetane Number 3500 JP-5 45 3000 80% JP-5/20% ATJ 42 2500 70% JP-5 2000 70% JP-5, 30% ATJ 70% JP-5, 30% optimal surr. ATJ 40.4

RPM (rev/min) RPM 1500 70% JP-5, 30% isododecane Optimal surrog. 40.2 70% JP-5, 30% isocetane JP-5 Isododecane 40.6 1000 60% JP-5, 40% ATJ Isocetane 39.1 80% JP-5, 20% ATJ 500 0 10 20 30 60% JP-5/40% ATJ 38 time since start (sec)

• Navy target: 10 s for emergency diesel generators Yanmar L100V single-cylinder diesel engine

12 Combustion of Fuels & Mixtures: Analysis of Engine RPM & Centane Number

4000 Derived Cetane Number 3500

3000 80% JP-5/20% ATJ 42 2500 70% JP-5 2000 70% JP-5, 30% ATJ 70% JP-5, 30% optimal surr. ATJ 40.4

• JP-5: ramps up to rated speed the fastest

13 Combustion of Fuels & Mixtures: Analysis of Engine RPM & Centane Number

4000 Derived Cetane Number 3500 JP-5 45 3000

2500 70% JP-5 2000 70% JP-5, 30% ATJ 70% JP-5, 30% optimal surr. ATJ 40.4

• JP-5: ramps up to rated speed the fastest • Increasing ATJ: Time to reach the rated speed increases – combustion fails above 60% JP-5/ 40% ATJ

14 Combustion of Fuels & Mixtures: Analysis of Engine RPM & Centane Number

4000 Derived Cetane Number 3500 JP-5 45 3000 80% JP-5/20% ATJ 42 2500 70% JP-5 2000 70% JP-5, 30% ATJ 70% JP-5, 30% optimal surr. ATJ 40.4

RPM (rev/min) RPM 1500 70% JP-5, 30% isododecane 70% JP-5, 30% isocetane JP-5 1000 60% JP-5, 40% ATJ 80% JP-5, 20% ATJ 500 0 10 20 30 60% JP-5/40% ATJ 38 time since start (sec)

• JP-5: ramps up to rated speed the fastest • Increasing ATJ: Time to reach the rated speed increases – combustion fails • All surrogates similar to ATJ: optimal surrogate 0.23 isocetane in isododecane

15 Combustion of Fuels and Mixtures: Change in Ignition Delay with Time

Large Yanmar Derived Cetane Number 100

80 60-40ATJ 45

60 80% JP-5/20% ATJ 42

40 70% JP-5/30% ATJ 40 IGD-ten (deg) 20 60% JP-5/40% ATJ 38

0 0 5 10 15 20 25 30 time since start (sec)

• JP-5: has the smallest ignition delay • ATJ: Ignition delay increases and combustion is uneven as ATJ is added and is accompanied by an increase in cetane number

16 Synergy of the Research Efforts

Physical/Chemical Properties Modeling Fuel Development of Properties & model composition Refinement Pure & multi- & validation component of data predictive models Preparation and measurement of properties of mixtures with known composition Judith Harrison

17 Molecular Dynamics Simulations: Predicting Fuel Properties Pre-Processing: Simulation Setup z (User Supplied Input or GC/MS measurement ) e.g.) Positions, velocities, charges, topology of all atoms, y temperature , flags for simulation parameters x

Calculate Interatomic Forces (Potential Function Selection) F = - dV(r)/dr V = AIREBO1 OPLS-AA3 Bulk Properties: 2 or mod-LJ AIREBO Non-Reactive Force Fields, updated recently Hydrocarbon liquid Reactive Potentials, Input = Positions only Input = Positions, Topology, charges, etc. Fuel Properties of Interest (all as a function of temp) Mathematically Integrate Equations of Motion • Density -Predictor-Corrector, Berendsen Thermostat, Nose-Hoover • Bulk modulus - NVT, NVE or NPT dynamics • Heats of vaporization ----Future work----- Output or Calculation of Values for FFP Calculation • Viscosity • Surface Tension Creation of Algorithms: (1) scripts for creating fuel simulation • Heat of combustion systems, (2) calculation of run-time quantities, (3) creation of • Specific Heat data files and algorithms for post-processing analysis • Interfacial Tension

1J. Chem Phys. 112, 6472 (2000); 2J. Comp. Chem., 29, 601-611 (2008); 3J. Am. Chem. Soc. 118 , 11225 (1996) 18 Selecting Systems for Fuel Property Prediction

Strategy: Examine the performance of the mod-LJ AIREBO and OPLS-AA potentials predicting properties as a function of temperature of complex, pure hydrocarbons and surrogate mixtures. USNA collaborators are able to provide any needed experimental data. For example:

J. Chem. Eng. Data, (2014) 59, 1334. AJT data/surrogates: J. Chem. Eng. Data, (2015) 60, 1157.

Pure Hydrocarbons (aliphatic and aromatic): n-dodecane, n-hexadecane, n- octadecane, iso-octane, 2,2,4,4,6,8, 8-heptamethylnonane (isocetane), 1-dodecene, methylcyclohexane, trans-decalin, tetralin, trimethylbenzene, toluene, 1-methylnapthalene

Binary Surrogates: • n-dodecane and 2,2,4,4,6,8, 8-heptamethylnonane (isocetane) • n-hexadecane and 2,2,4,4,6,8,8-heptamethylnonane (isocetane)

Multi-component Surrogates (up to 12 components): • 7 multicomponent surrogates examined

For all predicted data see: Mooney et al, Energy and Fuels, submitted and under review 19 Predicted Properties of Pure Hydrocarbons from MD

• Both potentials do a reasonable job predicting the densities of pure hydrocarbons. Slight degradation when predicting heats of vaporization.

• More difficulty predicting bulk modulus

Mooney et al, Energy and Fuels, submitted and under review 20 Predicted Properties of Multicomponent Surrogates

- Small degradation of performance when predicting densities of multicomponent surrogates compared to pure hydrocarbons. (Note: OPLS-AA unable to predict binary component densities.)

- Identification of issues preventing the quantitative prediction of bulk modulus are under investigation.

Mooney et al, Energy and Fuels, submitted and under review 21 MD Simulations yield insights unavailable to experiments 50/50 Mixture of n-hexadecane & isocetane

Hexadecane and isocetane are segregated in binary mixtures.

Straight-chain molecule behaves differently in mixture than in pure hydrocarbon.

22 Summary

• STUDY, MEASURE & PREDICT: Our research seeks to develop a fundamental understanding of how fuel composition impacts fuel properties and combustion behavior in (diesel) engines of interest to the military. This work is ultimately directed at developing the ability to predict the properties and performance of a fuel given knowledge of its chemical composition; this would, in turn, greatly facilitate the “fit for purpose” determination of fuels in specific Naval engines.

• EDUCATE: Our research is also directed at the education of midshipmen in the areas of research relevant to Navy fuels. This work provides midshipmen with hands-on project based learning experiences that are critically relevant to the future of the Navy, and informs these future Navy leaders on aspects of science and engineering that will positively impact their future decisions.

• SUPPORT & COLLABORATE: We provide scientific and engineering support, assistance, and collaboration to NAVAIR Patuxent River Fuels & Lubricants Branch in order to help them respond to emerging Navy fuel needs.

23 Acknowledgements & Collaborators

Postdocs: Brian H. Morrow (current), Kate Brown, Kurt Sweely, Barbara L. Mooney, Keith VanNostrand

Collaborators: M. Todd Knippenberg & J. David Schall

ONR: Funding

US Naval Academy: Facilities & Personnel Papers & Presentations

Reviewed Journal Publications . In Review • Luning Prak, D. J., Cowart, J.S., Trulove, P.C., Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of Bicyclohexyl and 1,2,3,4-Tetrahydronaphthalene or Trans-decahydronapthalene at (293.15 to 373.15) K and 0.1 MPa, submitted to Journal of Chemical and Engineering Data, Sept 14, 2015. • Mooney, B. L., Van Nostrand, K., Luning Prak, D., Trulove, P. C., Morris, R. E., Harrison, J.A., Knippenberg, M. T., Elucidating the Properties of Surrogate Fuel Mixtures using Molecular Dynamics, submitted to Energy and Fuels, June 29, 2015.

Published • Luning Prak, D. J., Jones, M. H., 2015, “Developing Surrogate Mixtures for Alternative Jet Fuels from n-Tetradecane and Isododecane” Journal of Undergraduate Chemistry Research, 14, 50 − 54. • Luning Prak, D. J., Jones, M. H., Trulove, P. C., McDaniel, A. M., Dickerson, T., Cowart, J., 2015, “Physical and Chemical Analysis of Alcohol-to-Jet (ATJ) Fuel and Development of Surrogate Fuel Mixtures” Energy and Fuels, 29, 3760 − 3769. • Cowart, J. S., Luning Prak, D. J., Hamilton, L. J., 2015, “The effects of fuel injection pressure and fuel type on the combustion characteristics of a diesel engine,” Journal of Engineering for Gas Turbines and Power, 137, 10151-1 − 101501-9. • Luning Prak, D. J., Jones, M. H., Cowart, J. S., Trulove, P.C., 2015, “Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of 2,2,4,6,6-Pentamethylheptane and 2,2,4,4,6,8,8-Heptamethylnonane at (293.15 to 373.15) K and 0.1 MPa and Comparisons with Alcohol-to-Jet Fuel,” Journal of Chemical and Engineering Data, 60, 1157−1165. • Brown, E. K., Palmquist, M., Luning Prak, D. J., Mueller, L. M., Bowen, S. S., Sweeley, K., Ruiz, O. N., Trulove, P. C., 2015, “Interaction of Selected Fuels with Water: Impact on Physical Properties and Microbial Growth” Journal of Petroleum & Environmental Biotechnology, 6, 204−212. • Luning Prak, D. J., Cowart, J. S., Trulove, P. C., 2014, “Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of n-Heptane + 2,2,4-Trimethylpentane at (293.15 to 338.15) K,” Journal of Chemical and Engineering Data, 59, 3842−3851.

25 Papers & Presentations

Reviewed Journal Publications cont. . • Luning Prak, D. J., McDaniel, A. M., Cowart, J. S., Trulove, P. C., 2014, “Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of N-Hexadecane + Ethylbenzene or + Toluene at (293.15 to 373.15) K and 0.1 MPa,” Journal of Chemical and Engineering Data, 59, 3571−3585. • Cowart, J., Raynes, M., Hamilton, L., Luning Prak, D., Mehl, M. Pitz, W., 2014, “An Experimental and Modeling Study into Using Normal and Isocetane Fuel Blends as a Surrogate for a Hydro-Processed Renewable Diesel (HRD) Fuel,” Journal of Energy Resources Technology, 136, 032202− 1 − 032202-9. • Cowart, J., Hamilton, L., Luning Prak, D., 2014, ”Predicting the Physical and Chemical Ignition Delays in a Military Diesel Engine Running n-Hexadecane Fuel,” Journal of Engineering for Gas Turbines and Power, 136, 071505-1 − 071505-7. • Luning Prak, D. J., Alexandre, S. M., Cowart, J. S., Trulove, P.C., 2014, “Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of N-Dodecane with 2,2,4,6,6-Pentamethylheptane or 2,2,4,4,6,8,8- Heptamethylnonane,” Journal of Chemical and Engineering Data, 59, 1334−1346. • Hamilton, L., Luning Prak, D.J., Cowart, J., McDaniel, A., Williams, S., Leung, R., 2014, “Direct Sugar to Hydrocarbon (DSH) Fuel Performance Evaluation in Multiple Diesel Engines,” SAE International Journal of Fuels and Lubricants, 7, 270−282. • Luning Prak, D.J., Morris, R.W., Cowart, J.S., Hamilton, L.J., Trulove, P.C., 2013, “Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Direct Sugar to Hydrocarbon Diesel (DSH-76) and Binary Mixtures of N- Hexadecane and 2,2,4,6,6-Pentamethylheptane,” Journal of Chemical and Engineering Data, 58, 3536−3554. • Luning Prak, D.J., Brown, E.K., Trulove, P.C., 2013, “Density, Viscosity, Speed of Sound, and Bulk Modulus of Methyl Alkanes, Dimethyl Alkanes, and Hydrotreated Renewable Fuels,” Journal of Chemical and Engineering Data, 58, 2065−2075. • Luning Prak, D.J., Cowart, J.S., Hamilton, L. J., Hoang, D.T., Brown, E.K., Trulove, P.C., 2013, “Development of a surrogate mixture for Algal-based hydrotreated renewable diesel,” Energy and Fuels, 27, 954−961. • Luning Prak, D.J., Trulove, P.C., Cowart, J.S., 2013, “Density, Viscosity, Speed of Sound, Surface Tension, and Flash Point of Binary Mixtures of N-hexadecane and 2,2,4,4,6,8,8-Heptamethylnonane and of Algal-Based Hydrotreated Renewable Diesel,” Journal of Chemical and Engineering Data, 58, 920−926. • Cowart, J., Carr, M., Caton, P. A., Stoulig, L., Luning Prak, D., Moore, A., Hamilton, L. J., 2011, “High Cetane Fuel Combustion Performance in a Conventional Military Diesel Engine,” SAE International Journal of Fuels and Lubricants, 4, 34−47.

26 Papers & Presentations

Reviewed Book Chapters and Conference Proceedings In Review • McDaniel, A., Dickerson, T., S., Luning Prak, D., Hamilton, L., Cowart, J., A Technical Evaluation of New Renewable Jet and Diesel Fuels Operated in Neat Form in Multiple Diesel Engines, paper submitted to the SAE 2016 World Congress & Exhibition, April 2016. • Bermudez, E., McDaniel, A., Dickerson, T., S., Luning Prak, D., Hamilton, L., Cowart, J.Start-up and Steady-State Performance of a New Renewable Hydro-processed Depolymerized cellulosic diesel (HDCD) in Multiple Diesel Engines, paper submitted to ASME Internal Combustion Engine Division Conference in November 2015.

Published • Dickerson, T., McDaniel, A., Williams, S., Luning-Prak, D., Hamilton, L., Bermudez, E., Cowart, J., 2015, “Start-up and Steady- State Performance of a New Renewable Alcohol-To-Jet (ATJ) Fuel in Multiple Diesel Engines”, SAE 2015 World Congress & Exhibition in April 2015, SAE Technical Paper 2015-01-0901, 2015, doi:10.4271/2015-01-0901. • Hamilton, L. J., Cowart, J. S., Luning-Prak, D. J., Caton, P. A., 2012, “An experimental study of normal-hexadecane and isododecane binary fuel blends in a military diesel engine,” Proc. ASME. 55096, ASME 2012 Internal Combustion Engine Division Fall Technical Conference, September 23, 2012; American Society of Mechanical Engineers (ASME) Paper ICEF2012-92151, 191−203. • Caton, P. A., Williams, S. A., Kamin, R. A., Luning-Prak, D. J., Hamilton, L. J., Cowart, J. S., 2012,“Hydrotreated Algae Renewable Fuel Performance in a Military Diesel Engine,” Proc. ASME. 44663, ASME 2012 Internal Combustion Engine Division Spring Technical Conference, May 6−9, 2012; American Society of Mechanical Engineers (ASME) Paper ICE2012- 81048, 121−132.