ORNL is managed by UT-Battelle, LLC for the US Department of Energy

Overview of ORNL’s Combustion Portfolio Relevant to Fluid PowerJim Szybist*

October 24, 2019

CCEFP Summit, University of Wisconsin

*Presenting for the numerous staff member at ORNL whose work is included in this presentation

22

Acknowledgements• DOE Vehicle Technologies Office• DOE Bioenergy Technologies Office• Fuels, Engines, Emissions Research Center (FEERC) colleagues

– Jun Qu, Mike Kass, Brian Kaul, Eric Nafziger, Scott Curran, Derek Splitter, Brian West, Robert Wagner, and more…

33

Main Campus and Spallation Neutron Source (inset)

44

ORNL is DOE’s largest multi-program science and energy lab

3,200researchguests

annually

Nation’s largest

materials research portfolio

$1.8B budget

Nation’s most diverse

energy portfolio

Forefrontscientific

computing facilities

World-class

research reactor

$750M modernization

investment

4,750employees

World’s most intense

neutronsource Managing

major DOE projects: US ITER, exascale

computing

2,203journal articles

published in CY15 185

inventiondisclosures

in FY16

83patents issuedin FY16

55

ORNL Sustainable Transportation Program (STP)Pursuing a diversity of technologies to reduce environmental impact while establishing predictable, reliable, and secure personal mobility and freight movement

ACCELERATING ELECTRIFICATION• Wireless power transfer• Advanced power electronics and

electric motors• Next generation battery materials

and manufacturing• Fuel cells

IMPROVING VEHICLE EFFICIENCY• Advanced engine and emissions

controls• Hybrid powertrains and vehicle

systems integration• Lightweight and propulsion

materials• Advanced lubricants

DEVELOPING SUSTAINABLE FUELS• Co-development of fuel and engine

technologies• Alternative fuel GHG analysis• Critical data for the introduction of

new fuels

ENABLING INTELLIGENT SYSTEMS AND OPERATIONS• Predictive data for decision making• Data sciences and cyber security• fueleconomy.gov• Congestion management• Efficient operation of commercial vehicles

REVOLUTIONIZING MANUFACTURING• Additive manufacturing for

components to full vehicles• More efficient processes

66

Examples of significant ORNL contributions to transportation

Material Science & Technology• CF8C-plus steel, Al alloys, and ceramics used in

millions of engines• Leading development of affordable carbon fiber• Diagnostics in support of emissions controls

Data, Analysis, Modeling• NAS and congressional testimony

• Transportation Energy Databook

• Freight analysis framework (DOT)

• “Billion Ton” biomass study

• Logistics modeling (DOD)

• FuelEconomy.gov

Fuel Supply and Emissions Certification

• Data cited in EPA 15 ppm sulfur diesel fuel rule

• Data cited by EPA in 15% ethanol waiver decision

• NMOG correlation codified in CARB LEV III and EPA Tier 3 rule

Vehicle Propulsion Systems• Innovative emissions diagnostics enables clean

diesel engine

• 15+ years of high efficiency combustion research

• Go-to laboratory for demonstrating DOE program engine efficiency goals

• Development and benchmarking of HEV components

77

Laboratory Capabilities Relevant to Fluid Power

• Lubricants (Jun Qu)• Combustion• Alternative Fuels

88

Laboratory Capabilities Relevant to Fluid Power

• Lubricants (Jun Qu)• Combustion• Alternative Fuels

99

ORNL’s Eco-Friendly, Anti-Friction/Wear Ionic Liquids for Hydropower/Hydraulic LubricationBackground: Environmentally Acceptable Lubricants (EALs) are highly desired, but conventional additives are either toxic or ineffective.

Approach: Develop eco-friendly ionic liquids as EAL additives• Good solubility in EALs• Superior lubricating

performance• Low or no toxicity in aquatic

environments: o EPA chronic toxicity test

using Ceriodaphnia dubia

Technical contact: Jun Qu (865-576-9304, qujn@ornl.gov)

Test lubricants: PAG (Polyalkylene glycol) PAG+ 5% additive

(ZDDP or IL)Diluted to 10 ppm in water

(0.5 ppm ZDDP or IL)

PAG OSP Mineral0

1

2

3

4

5

Wea

r Vol

ume

(105 µ

m3 )

No additive+ 0.5% ZDDP+ 0.5% IL-1

Tribology

Neat PAG+ ZDDP+ IL-1

Toxicity

Survival rate Reproduction rate

0 0 0 0 0 0

1010

Background: Environmentally friendly lubricants desired for hydropower and hydraulics

• EPA-approved base oils of Environmentally Acceptable Lubricants (EALs) include – Water-based (only for limited light-duty components) and – Oil-based, e.g., vegetable oils, synthetic esters, polyalkylene glycols (PAGs).

• Lack of eco-friendly, effective anti-wear (AW) additives– Conventional AW and EP additives, such as ZDDPs, are not allowed in EALs due to

their toxicity. – Traditional ashless (metal-free) additives, such as TPPT, have lower toxicity but their

wear protection is somewhat inferior.

ZDDP TPPT

The idea: developing eco-friendly ionic liquids as novel anti-wear and friction-reducing additives.

1111

Background: Ionic liquids for lubrication

Ionic liquids (ILs) are ‘room temperature molten salts’, composed of cations & anions, instead of

neutral molecules.

NR

N NR

+ N++

R1

R2 R3

R4 P

+R1

R2 R3

R4

Tetraalkyl-ammonium

Tetraalkyl-phosphonium

1-alkyl-3-methyl-imidazolium

N-alkyl-pyridinium

1

2

3

4 5

(R1,2,3,4 = alkyl)

NR

N NR

+ N++

R1

R2 R3

R4 P

+R1

R2 R3

R4

Tetraalkyl-ammonium

Tetraalkyl-phosphonium

1-alkyl-3-methyl-imidazolium

N-alkyl-pyridinium

1

2

3

4 5

(R1,2,3,4 = alkyl)

[PF6]- [BF4]-

[CF3CO2]-, [NO3]-[CH3CO2]-

[BR1R2R3R4]-

[CF3SO3]-[(CF3SO2)2N]-

Br-, Cl-, I-

[Al2Cl7]-, [AlCl4]-[(C2F5SO2)2N]- (BETI)

(Tf2N)[PF6]- [BF4]-

[CF3CO2]-, [NO3]-[CH3CO2]-

[BR1R2R3R4]-

[CF3SO3]-[(CF3SO2)2N]-

Br-, Cl-, I-

[Al2Cl7]-, [AlCl4]-[(C2F5SO2)2N]-[(C2F5SO2)2N]- (BETI)

(Tf2N)

[P(O)2(OR)2]− (phosphate)[P(O)2(R)2]− (phosphinate)

Common Cations

Common Anions

• ILs as neat lubricants or base stocks– High thermal stability (up to 500 oC)– High viscosity index (120-370)– Low EHL friction w/ low pressure-viscosity coefficient– Wear protection by tribo-film formation– Technical problem: Many earlier ILs corrosive

• ORNL developed the 1st group of non-corrosive ILs in 2006 (U.S. patent #7,754,664)

• ILs as oil additives for engine/gear lubrication– Potential multi-functions: AW/EP, FM, etc.– Ashless low sludge– Allow the use of lower viscosity oils– Advantage: cost effective and easier market penetration– Technical problem: most ILs insoluble in oils (<<1%)

• ORNL invented 1st group of oil-soluble ILs in 2010 (U.S. patent #9,957,460, 2014 R&D 100 Award)

• ILs as eco-friendly lubricant additives for hydropower/hydraulics

– Problem: many ILs as toxic as traditional ZDDP• ORNL invented the 1st group of eco-friendly ILs in

2019 (ORNL Invention Disclosure)

1212

Candidate eco-friendly ionic liquids possess good oil solubility and high thermal stability

Oil solubility (wt. %)PAG OSP Mineral oil

ILs previously developed for

engine/gear oils

[P8888][DEHP] >5% >5% >5%[N888H][DEHP] >5% >5% >5%

New candidate eco-friendly ILs for hydropower/

hydraulic lubrication

IL-1 >5% >5% <1%IL-2 >5% >5% <1%IL-3 >5% >5% <1%IL-4 >5% >5% <1%IL-5 >5% >5% >5%IL-6 >5% >5% >5%

0 200 400 600 8000

20

40

60

80

100

Wei

ght (

%)

Temperature (0C)

ZDDP [N888H][DEHP] IL-1 IL-2 IL-4 IL-1 IL-2

AirN

2

0 100 200 300 4000

20

40

60

80

100

Wei

ght (

%)

Temperature (0C)

PAG OSP Mineral

• Candidate eco-friendly ILs are fully soluble in PAG (polyalkylene glycol) and OSP (oil-soluble PAG), and latest are soluble in mineral oil as well.

• Candidate eco-friendly ILs have thermal decomposition temperatures of 120-250 0C with strong resistance to oxidation (higher than peak operation temperature of hydropower hydraulic lubrication)

1313

Candidate ionic liquids demonstrated superior friction and wear reducing characteristics

PAG OSP Mineral0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14Fr

ictio

n C

oeffi

cien

t No additive +0.5 wt% ZDDP +0.5 wt% [N888H][DEHP] +0.5 wt% IL-1 +0.5 wt% IL-2

PAG OSP Mineral0123456 No additive

+0.5 wt% ZDDP +0.5 wt% [N888H][DEHP] +0.5 wt% IL-1 +0.5 wt% IL-2

Wea

r Rat

e (1

0-9 m

m3 /N

·m)

• IL-1 outperformed the conventional ZDDP by o >20% friction reduction and >80% wear reduction in mineral oilo >30% friction reduction and >90% wear reduction in PAG

1414

EPA toxicity tests using Ceriodaphnia dubiaToxicity test in aquatic environments: o EPA chronic toxicity test using Ceriodaphnia dubiaideal microorganisms for toxicity testing because of their short reproductive cycle, sensitivity to water quality and easy to culture in an aquarium

o Test lubricants: PAG neat oil, PAG+5%ZDDP, PAG+5%ILs (IL-1, IL-2, [N888H][DEHP], [P8888][DEHP])

PAG base oil is selected because of the high water solubility

o Dilution in water: 10 ppm lubricant (0.5 ppm ZDDP or IL)o Temperature: 25 oC, 10 replicates for each lubricantso Acute toxicity test (5 days): survival rateo Chronic toxicity test (7 days): survival and reproduction

Die

ter E

bert

2006EggsAntennae

Gut

Heart

1515

Newly developed ILs demonstrated low/no toxicity• Unlike ZDDP or earlier-developed ILs for engine/gear oils that killed all daphnia,

ORNL new candidate eco-friendly ILs caused no death or reduced reproduction!

Neat PAG PAG + 5% IL-1 PAG + 5% IL-2PAG + 5%

[N888H][DEHP]PAG + 5%

[P8888][DEHP]PAG + 5%

ZDDPDay 1 0 0 0 0 0 0Day 2 0 0 0 0 0 0Day 3 32 36 45 0 0 0Day 4 2 0 13 0 0 0Day 5 91 98 82 0 0 0Day 6 128 159 141 0 0 0Day 7 175 201 172 0 0 0

Grand Total 428 494 453 0 0 0

Neat PAG PAG + 5% IL-1 PAG + 5% IL-2PAG + 5%

[N888H][DEHP]PAG + 5%

[P8888][DEHP]PAG + 5%

ZDDPDay 1 10 10 10 10 10 10Day 2 10 10 10 6 0 0Day 3 10 10 10 0 0 0Day 4 10 10 10 0 0 0Day 5 10 10 10 0 0 0

Survival rate in acute toxicity test (5 days)

Reproduction in chronic toxicity test (7 days)

IL-1 has demonstrated much improved lubricating performance and significantly reduced toxicity than ZDDP!

1616

Laboratory Capabilities Relevant to Fluid Power

• Lubricants (Jun Qu)• Combustion• Alternative Fuels

1717

Primarily Automotive Focused, but Wide Range of Engine Sizes and Combustion Approaches• Eight engine dynamometer laboratories at ORNL

– Most with double-ended dynamometers– Includes single and multi-cylinder engines

• Research includes spark ignition, compression ignition, and numerous advanced compression ignition strategies

• Research includes a variety of engine sizes– Engines for unmanned aerial vehicles (UAVs), < 100 cc/cylinder– Automotive SI engines, 400-600 cc/cylinder– MD and HD diesel engines, up to 2,500 cc/cylinder– Scaled-down version of marine diesel engine, 4,000 cc/cylinder

• Extensive fuels research– Co-Optima initiative to co-develop biofuels and new combustion strategies– Liquid and gaseous fuels research (natural gas and propane)

• Extensive emission controls research

EGR

Plenum

Intake

Exhaust

Plenum

1818

Exxon-Mobile is Funding Lubricant Research on Custom 1/10 Scale Engine for Marine Diesel

In part, lubricant research is motivated in fuel uncertainty for marine industry…

19

*BP (British Petroleum). 2018. BP Statistical Review of World Energy, 67th Edition.**DNV GL. 2018. “Current Price Development Oil and Gas.” Accessed December 2018. https://www.dnvgl.com/maritime/lng/current-

price-development-oil-and-gas.html.

Large marine vessels are fueled using a range of distillate and residual fuels for use in diesel-type engines.

Marine fuel typeEstimated quantity consumed (million

tonnes/year)*

Estimated cost**

($$/metric ton) ($$/gallon)HFO (residual fuel) 230 460 1.72MGO (distillate fuel) 10 700 2.62MDO (MGO/HFO blend) 65 ~700 ~2.62

Residual Fuel Oils Distillate FuelsHigh sulfur/asphaltene content contributes to high BC and SOxemissions

Lower sulfur content, produce significantly lower high BC and SOxemissions than HFO

High viscosity requires heat energy to achieve proper flow characteristics Does not require additional heat

High levels of ash, cat fines, and water require onboard processing and storage No waste generation

Highly variable chemistry may cause incompatibilities and stratification

More consistent fuel chemistry

Deep sea use Higher cost precludes deep sea use

This Photoby Unknow

n Author is licensed under C

C BY-SA

Ships typically hold between 15,000 and 18,000 containers. Each container is roughly the size of a tractor trailer rig.

20

IMO 2020 Sulfur cap will mandate the development of new marine lubricants to cope with changes to fuel lubricity and slow speed operation.

• HFO contains up to 3.5% sulfur and requires heating to flow.

• In order to comply with the low sulfur ruling, some fuel suppliers are expected to blend in higher levels of distillates.

• 40,000 ships burn 250-300 tonnes of fuel/day – Same order of magnitude as US on-road diesel consumption– This global increase in diesel demand will potentially raise the cost of diesel fuel.

• However, many refineries state that they can meet the low sulfur specifications through additional processing of crude.

• Lots of unknowns at the moment.

2121

Laboratory Capabilities Relevant to Fluid Power

• Lubricants (Jun Qu)• Combustion• Alternative Fuels

2222

Additionally, Emissions Regulations for Nonroad Diesel Engines May Become More Stringent in Future• Historically nonroad diesel engine emission regulations have lagged highway regulations

– Highway engines reduced NOx emissions to 0.2 g/bhp-h in 2007– Proposed California rule will reduce that to 0.02 g/bhp-h in future

• Non-road engines > 56 kW– NOx Currently at 0.4 g/kW-h (0.3 g/bhp-h)– Further reductions would necessitate lean NOx emission controls

• Alternatives to diesel engines for on-highway to meet NO– Cummins producing 12 L, 400 hp engine using natural gas– Stoichiometric fueling allows the use of a 3-way catalyst– Peak efficiency of some SI engine now exceeds 40%

• Propane and natural gas are both alternatives with substantial price benefits and simplify emissions controls

– Stoichiometric combustion with 3-way catalyst

*screenshot from www.cngnow.com on 10/21/19

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

1970 1980 1990 2000 2010 2020

2018

$/ D

iese

l Gal

lon

Equi

vale

nt

Diesel Price (2018 $/DGE)

Propane Price (2018 $/DGE)

*Data from the Transportation Energy Data Book**Reflects refinery sale price, does not include

transportation and sales tax

2323

High Efficiency SI Research Using is a Strength of ORNL Combustion Program• Pressure-Temperature (PT) Autoignition Framework

– Bringing kinetics to applied understanding

• Fuel/lubricant interactions on LSPI propensity

• Custom long-stroke engine for high efficiency

• Fuel reforming for thermochemical recuperation and EGR limit extension

24

Octane Index (OI) Allows Fuel Quality Expectations to be Set for both SI and ACI Combustion Strategies

• Relative ranking of fuels change with operating condition– Research octane number (RON) and motor octane number (MON) are

different because they represent different engine conditions

• OI, pioneered by Kalghatgi, uses a variable K to account for changing operating conditions (SAE 2001-01-3584, 2005-01-0239)

– OI = RON – K*(RON – MON)

RON MON

Fuel 1 98 98

Fuel 2 95 85

Fuel 3 93 87

Fuel 4 97 91

Fuel 5 92 82

Which Fuel is Best? It Depends.

Fuel Ranking

RON Condition

s

MON Conditions AKI K = -0.5 K = -1 K = -2

Best Fuel 1 Fuel 1 Fuel 1 Fuel 2 Fuel 2 Fuel 2

Fuel 4 Fuel 4 Fuel 4 Fuel 4 Fuel 4 Fuel 5

Fuel 2 Fuel 3 Fuel 2 Fuel 1 Fuel 5 Fuel 4

Fuel 3 Fuel 2 Fuel 3 Fuel 5 Fuel 3 Fuel 3

Worst Fuel 5 Fuel 5 Fuel 5 Fuel 3 Fuel 1 Fuel 1

ACI Ranking K = 2

Least Reactive Fuel 1

Fuel 4

Fuel 3

Fuel 2

Most Reactive Fuel 5

High Reactivity Allows ACI to be Achieved More

Readily

25

Operating Condition Determines Pressure-Temperature Trajectory, Dictating Autoignition Kinetics

25

26

Comparing Constant Ignition Delay for Different Fuels Enable a Better Understanding of RON, MON, and OI

For Naturally Aspirated Engine at WOT, Fuels

are Similar

Under boost, High S fuel is

Better

8ms ID Contours

Under MON Conditions, Low S fuel is Better

Beyond MON Conditions – Unclear

Which Fuel More Reactive

2727

Research shows path to high BTE, λ=1, SI with 91 RON

• Honda high S/B ratio research engine (SAE 2015-01-1263)– Enabled high EGR without detrimental effect on combustion duration– High rc used (~17:1 geometric, ~12.4:1 effective) miller cycle

• Can become air/mivc limited at increased loads– 91 RON pump gasoline used with high boost (trapped mass)

2828

Actual Design “Combines” Two Engines• Rod/block pinch issue

– Compromise was reduce rod/stroke ratio

• Cylinder head from LNF – Surman “camless” valve system– Late IVC possible

• Block is billet Aluminum– Short block modeled after drag

racing engine

• Crank and rod are custom billet steel (300M)

• Internally balanced – First order balance from opposite bob

weight

2929

Engine Uses Sturman Valves with Custom Block

3030

Using Propane as Fuel, Very Fast Combustion and Projected BTE = 40% for Stoichiometric SI

• GTE > 46% and conservative correlations used to project 40% BTE

• High S/B configuration significantly reduces combustion duration because of high turbulence

4 6 8 10 12 14 16 18 20 2236384042444648 30

323436384042444626

2830323436384042

propane 9.2:1=rc, S/B=1 propane, 13.3:1=rc, S/B=1 propane, 13.3:1=rc, S/B=1.5 propane, 16.8:1=rc, S/B=1.5 propane, 16.8:1=rc, S/B=1.5, LIVC + EGR

η gr

oss

(%)

IMEPg (bar)

η ne

t (%

)

η br

ake

(%)

4 6 8 10 12 14 16 18 20 225

10

15

20

25 94

96

98

10012

16

20

24

28

propane 9.2:1=rc, S/B=1 propane, 13.3:1=rc, S/B=1 propane, 13.3:1=rc, S/B=1.5 propane, 16.8:1=rc, S/B=1.5

CA50

(°CA

)

IMEPg (bar)

η co

mbu

sito

n ( %

)

CA2

- CA

85 (°

CA)

3131

Summary• ORNL has a diverse range of expertise that can be applied to s

science and engineering challenges, included fluid power• Developing a next-generation ionic lubricants that provide

superior performance and are environmentally acceptable• Wide range of experience and expertise with engines,

combustion strategies, and alternative fuels– Facilities cover a wide size range of engines and combustion type– Marine fuel change may increase demand and cost of diesel fuel in

the near future,– ORNL capabilities can help design and identify high efficiency

operation with alternative fuels