Thrust 1 Technical Overview Jim Szybist (ORNL), Dan Gaspar (PNNL) September 14, 2016

1 Thrust 1 Approach

• From biomass to blendstock • Blendstock properties • Fuel properties and engine performance • Advanced spark ignition engine performance

2 From biomass to blendstocks - spark ignition 3 candidates identified • Identified 9 molecular classes suitable for further evaluation • Paraffins (especially highly branched paraffins), olefins, cycloalkanes, aromatics, alcohols, furans, ketones, ethers, and

• Developed list of candidates from these classes based on: • Open literature sources • Ongoing National Laboratory research • Proposed plausible pathways from biomass to spark ignition blendstocks

• Constructed tiered screening process based on fuel merit function, including expected optimal values for properties Fuel selection “funnel”

4 5 • Applied tiered screening process >400 potential candidates in Fuel Property Database to generate ~40 candidates* • Focused on high octane components (>98 RON) to enable downsized, down-speeded, boosted SI engines • Other criteria included: • Soluble in hydrocarbon • Not OSHA known or suspected human carcinogen or reproductive toxin • Biodegradation via EPA’s BIOWIN (coupled to water solubility) • Boiling point <165 oC and freezing point <10 oC • Low expected corrosivity Thrust I candidates meeting Tier 1 criteria

Alcohols Aromatics Ethers Ethanol (reference only) 1,3,5-trimethylbenzene (mesitylene) Methoxybenzene (anisole) Methanol Vertifuel (60%+ aromatics) n-Propanol Fractional condensation of sugars plus upgrading Furans 2-Propanol Methanol-to-gasoline 2-Methylfuran 1-Butanol Catalytic fast pyrolysis 2,5-Dimethylfuran 2-Butanol Catalytric conversion of sugars 40/60 Mixture of 2-methylfuran/2,5- dimethylfuran 2-Methylpropan-1-ol (isobutanol) 2-Methylbutanol Esters Ketones 2-Methyl-3-buten-2-ol Acetic acid, methyl () 2-Propane (acetone) 2-Pentanol Butanoic acid, methyl ester () 2-Butane (methylethylketone; MEK) Guerbet alcohols Pentanoic acid, methyl ester (methyl pentanoate) 2-Pentanone 2-Methylpropanoic acid, methyl ester 3-Pentanone Alkanes 2-Methlybutanoic acid, methyl ester Cyclopentanone Isooctane Acetic acid, ethyl ester () 3-Hexanone High-octane gasoline blendstock Butanoic acid, ethyl ester (ethyl butanoate) 4-Methyl-2-pentanone (Methylisobutylketone; (triptane rich) MIBK) 2-Methylpropanoic acid, ethyl ester 2,4-Dimethyl-3-pentanone Alkenes Acetic acid, 1-methylethyl ester 3-Methyl-2-butanone Isooctene (2,4,4-trimethyl-1-pentene) Acetic acid, butyl ester () Acetic acid, 2-methylpropyl ester Multifunctional Mixtures Acetic acid, 3-methylbutyl ester Methylated lignocellulosic bio-oil Anaerobic acid fermentation plus esterification

6 7

Selected 20 candidates for analysis from Tier 1 list

Selection based on practical considerations: • Clear production pathway with balance between production approaches • Cover the chemistry/functional group space • Series of candidates within alcohols and esters which provide some systematic variation of structure 20 ASSERT Molecules/Mixtures 8 0 Ethanol (Reference) 11 Anaerobic acid fermentation 1 Methanol and esterification mixture 12 2-pentanone 2 1-butanol 3 2-methyl-butanol 13 Methylethylketone (2- butanone) 4 2-butanol 14 2,2,3-trimethyl-butane 5 Isobutanol (2-methylpropan-1- ol) 15 Isooctene 6 Guerbet alcohol mixture 16 Vertifuel (60%+ aromatics) 7 2,5-dimethylfuran/2- methylfuran mixture 17 Fractional condensation of 8 Acetic acid, methyl ester sugars + upgrading (methyl acetate) 18 Methanol-to-gasoline 9 Acetic acid, ethyl ester (ethyl 19 Catalytic fast pyrolysis acetate) 10 Acetic acid, butyl ester (butyl 20 Catalytic conversion of sugars acetate) Thank You Thrust I Engine Research • Focused in next-generation SI engines Assumptions Being Evaluated • Taking a fuel-property approach to new fuel candidates 1. Fuel properties correctly *SI engines accounted for 72% of on-highway describe the fuel’s performance energy consumption in the U.S. in 2013. (Energy Transportation Data Book, 2015). in modern SI engines.

2. Fuel property measurements The Central Fuel Hypothesis are valid across a wide range of If we identify target values for the critical fuel unconventional fuel chemistries properties needed to maximize efficiency and emissions performance for a given engine architecture, then fuels with those properties and values will provide comparable performance. Merit Function Allows Individual Fuel Properties to be Valued 11 Thrust I Research Aims to Refine the Merit Function Terms

Octane 4 RON Sensitivity 43 For K = -0.5  342 For K = -0.5  (푹푶푵 − ퟗퟐ) 231 For K = -0.5 풎풊풙 (푺풎풊풙 − ퟏퟎ)  −푲 120 Merit = ퟏ. ퟔ ퟏ. ퟔ -101 -1-20 Merit Function Merit -2-1 ∑ Heat of Vaporization Function Merit -3 -3-2

Merit Function Merit -4 -4-33500 88 9010 400 92 20 94 450 96 30 88HoV 90LFVRON [ 92 kJ/kg [ % 94 ]] 96 ퟎ. ퟎퟏ[푶푵/ 풌푱 풌품] 푯풐푽풎풊풙 − ퟒퟏퟓ [풌푱 풌품] -4 RON150 1.5442 6 44 82 4610 2.5 12 48 14 50 16 3 488 6 90 8 10 92 12 94 14 96 16 ퟏ. ퟔ FlameOctane SpeedRON PMISensitivity [ cm/s ] 3504Octane 6 8 400 Sensitivity10 12 450 14 16 푯풐푽 − ퟒퟏퟓ [풌푱 풌품] HoV [ kJ/kg ] 풎풊풙 Octane Sensitivity + 42 44 46 48 50 ퟏퟑퟎ Flame Speed [ cm/s ] 350 400 450 HoV [ kJ/kg ] Flame Speed Distillation 42 44 46 48 50 Particulate Emissions 0Flame10 Speed 20[ cm/s 30] LFV [ % ] 0 10150 20 30 풄풎 −푳푭푽 1.5LFV 2 2.5[ % ] 3 (푺 − ퟒퟔ ) ퟏퟓퟎ −푯(푷푴푰 − ퟐ. ퟎ)[ퟎ. ퟔퟕ + ퟎ. ퟓ(푷푴푰 − ퟐ. ퟎ)] 150 푳풎풊풙 풔 1.5 2PMI 2.5 3 ퟑ PMI Example 1: Clarifying the Effects of HoV on Knock Mitigation 12

30 • Inconsistencies in literature of HoV RON 96.5 (24% Isobutanol) 25 RON 96.6 (E20) impact on knock propensity RON 97.6 (30% Toluene)

] 20 • HoV effect only been observed when f 15 covariant with octane sensitivity aTDC 10 CA50[ • Expanded with new experimental 5 Matched RON and S Varying HoV results from ORNL and NREL 0 0 500 1000 1500 2000 • Main conclusion: HoV is a thermal Brake Mean Effective Pressure [ kPa ]

contributor to octane sensitivity Thermal Sensitivity Component 20 Chemical Sensitivity Component ) • Aligns the findings of seemingly - contrary literature findings 15 • Consistent with the vaporization 10 effects in the RON and MON tests 5

Octane Sensitivity ( Sensitivity Octane 0 0 10 20 40 60 80 100 Volumetric Ethanol Content (%) Further Research Shows that at Elevated Intake Temperatures, Impact of 13 HoV is Different from that of S

Data represents 20 maximum load at HoV constant 18 combustion RON = 99.2-101.6 595 kJ/kg phasing S = 10.7-12.2 16 472 kJ/kg [ bar ]

net 390 kJ/kg 14 IMEP

12 Isooctane, DI TSF 99.8, DI RON = 100 E40-TRF6x, DI E20+2%p-Cresol-TRF88, DI S = 0 10 30 40 50 60 70 80 90 100 Intake Temperature [ C ]

Fuels show fixed RON and S with varying HoV Example 2. Conditions of RON and MON Tests Raise Applicability Questions 14

CFR Engine Doesn’t Match Modern Engines PRFs Aren’t Representative Real-World Fuels Fueling System PRF’s are Paraffin Carbureted vs. Direct injection  Exhibit 2-stage ignition that is unique when Air Handling compared to most other fuels Naturally Aspirated vs. Boosted  The 2-stage ignition defines the octane Fixed Cam Position vs. Phasing number scale Combustion Phasing Advanced vs. Late Phasing Are RON and MON Still Applicable Additional Mismatches  Understanding of the beneficial nature of Intake Temperature Engine Speed octane sensitivity is becoming accepted  With new bio-derived fuels, do RON, MON Knock Detection and octane sensitivity still have the same Equivalence Ratio meaning? Combination of Experimental Investigations and Kinetic Modeling is 15 Providing Insight into Meaning of RON and MON

Experiments show some fuels exhibit pre- Kinetic modeling is being used to spark heat release in stoich SI engines understand the operating conditions in the • Boosted operating conditions temperature/pressure space • Elevated intake temperatures 40 Iso-Octane Condition C 35 7.0 30 6.0 25 5.0 4.0 20 3.0 RON MON 15 2.0

Condition B

Pressure [ bar ] Pressure [ bar 10 5 Condition A 0 600 650 700 750 800 850 900 9501000 Temperature [ K ] COV of IMEP [ % ] 24 22 1.000 2.000 20 3.000 18 4.000 Additional Thrust I Research Areas Include 16 5.000 16 6.000 14 7.000 8.000 12 9.000 10 EGR [% ] 8 Efficiency benefits of RON and MON 6 4 2 6 8 10 12 14 16 18 20 22 Improving HoV measurements for mixtures CA50 [ CA aTDCf ] 60 Methanol Investigating the impact of HoV on engine performance 50 Lean and EGR dilution tolerance 40

Ethanol 30 Fuel impacts on particulate emissions

20 Fuel impacts on catalyst light-off temperatures

Heat of Vaporization [kJ/MJ] Heat of Vaporization Toluene 10 Fuel impacts on low speed pre-ignition

Iso-octane N-heptane 0 40 45 50 55 60 Findings from Thrust I investigations will feedback to test the LFS at 1atm, 358K [cm/s] Average central fuels hypothesis and to calibrate the merit function LSPI (cycle #116) 200 12.5

175 Spark timing 10.0 150

125 7.5 Spark timing 100

75 5.0

Cylinder Pressure (bar) Pressure Cylinder 50 2.5

25 (volt) Signal Spark Primary Coil

0 0.0 -20 0 20 40 60 80 100  Crank Angle ( CA aTDCf) 17

Backup slides 18 Single The 20 includes a range of compositions compounds and functional groups: Simple mixtures 5 alcohols 1 alcohol mixture Complex mixtures 3 esters 1 furan mixture

2 ketones 5 hydrocarbon mixtures

1 paraffin 1 ester mixture

1 olefin 2 complex mixtures 19

Structural series within alcohols…

…and esters 20 Next steps

• Fill in process gaps as needed for ASSERT analysis • Examine blending behavior of subset of 20 • Distillation Properties via ASTM D86 in an RBOB; RVP from other methods • Oxidation Stability via ASTM D525 in an RBOB • Blending RON and MON in a 4 component surrogate w/ AKI about 88 or 89 Bio- Blended fuels blendstocks : mixtures, Base @ multiple blending single fuel ratios (10, compounds 20, 30 vol%)