The Energy InstituteEMS Energy Institute Dimethyl Ether - A Path to Use Natural Gas as a Transportation Fuel André Boehman EMS Energy Institute Department of Energy & Mineral Engineering The Pennsylvania State University Partners: Oberon Fuels Alternative Fuel Technology, LLC André Boehman EMS Energy Institute Department of Energy & Mineral Engineering The Pennsylvania State University Partners: Oberon Fuels Alternative Fuel Technology, LLC

The Energy InstituteEMS Energy Institute Natural gas vehicles are of great public and commercial interest direct displacement of petroleum from a domestic resource Efficient utilization of natural gas should be our goal But in what form? HCNG, CNG, LNG, or conversion to other fuel chemistry for more efficient usage? Dimethyl ether represents an emerging engine technology for NG utilization. Infrastructure build-out can piggyback on current LPG infrastructure Handles like propane Burns smokeless eliminates diesel particulate matter concerns Wont boil off if your vehicle sits for two weeks Natural gas vehicles are of great public and commercial interest direct displacement of petroleum from a domestic resource Efficient utilization of natural gas should be our goal But in what form? HCNG, CNG, LNG, or conversion to other fuel chemistry for more efficient usage? Dimethyl ether represents an emerging engine technology for NG utilization. Infrastructure build-out can piggyback on current LPG infrastructure Handles like propane Burns smokeless eliminates diesel particulate matter concerns Wont boil off if your vehicle sits for two weeks Why Consider DME?

The Energy InstituteEMS Energy Institute J. Eberhardt, DEER 2002 DME 61% the energy content of propane Similar energy content to ethanol on volume basis

The Energy InstituteEMS Energy Institute VehicleCycleTHC (g/mi) NMHC (g/mi) NO x (g/mi) CO (g/mi) CO 2 (g/mi) PM (g/mi) Btu/mi RTD Bus 1014-CNGCBD RTD Bus Diesel CBD Comparison of Emissions of Low Emissions Vehicle-Certified RTD Buses McCormick, Graboski, Alleman, Herring and Nelson, SAE CNG Vehicles Suffer From: èReduced compression ratio lower thermal efficiency èHigh unburned CH 4 emissions èCombination of high CH 4 emissions and reduced efficiency eliminates the H/C ratio benefit of CNG over diesel fuel with respect to CO 2eq emissions CNG Vehicles Suffer From: èReduced compression ratio lower thermal efficiency èHigh unburned CH 4 emissions èCombination of high CH 4 emissions and reduced efficiency eliminates the H/C ratio benefit of CNG over diesel fuel with respect to CO 2eq emissions ~ 1890 g/mi at 10*GWP of CH 4 ~ 2090 g/mi at 20*GWP of CH 4 ~ 3090 g/mi at 70*GWP of CH 4

The Energy InstituteEMS Energy Institute 1990s: èThomas and Staunton (SAE ) state DOE target is 10% > fuel economy than equivalent gasoline vehicle, but > 15% improvements are possible with turbocharged lean-burn operation. Alternative is CI NG engines, using diesel pilot, and recommended port gas injectors or DI NG injectors, and maybe a prechamber to enhance ignition. Diesel efficiency requires DI or IDI for the NG and provide >28 to 37% efficiency gain over gasoline. Their analysis was restricted to conventional combustion – dual fuel with micropilot or CI of the NG. èWeaver and Turner (SAE ) show that knock can occur in high BMEP engines, leading to derating of the engine to avoid knock or reduction of the fraction of energy from NG. At light load the very lean mixture may prevent effective burning of the homogeneous NG charge unless the engine is throttled. 1990s: èThomas and Staunton (SAE ) state DOE target is 10% > fuel economy than equivalent gasoline vehicle, but > 15% improvements are possible with turbocharged lean-burn operation. Alternative is CI NG engines, using diesel pilot, and recommended port gas injectors or DI NG injectors, and maybe a prechamber to enhance ignition. Diesel efficiency requires DI or IDI for the NG and provide >28 to 37% efficiency gain over gasoline. Their analysis was restricted to conventional combustion – dual fuel with micropilot or CI of the NG. èWeaver and Turner (SAE ) show that knock can occur in high BMEP engines, leading to derating of the engine to avoid knock or reduction of the fraction of energy from NG. At light load the very lean mixture may prevent effective burning of the homogeneous NG charge unless the engine is throttled. CNG Vehicle Efficiency Can we burn natural gas and have diesel or better efficiency? consider DME

Patron member Dimethyl-ether (DME) Methane Methanol Water Propane Butane Hydrogen CarbonOxygen 1.4 tons MeOH to 1 ton DME LPG What is DME? DME Background - What is DME? Synthetic LPG

DME Properties – Comparison with Other Fuels PropertyDMEDieselPropane Chemical FormulaC2H6OC2H6OC 10.8 H 18.7 C3H8C3H8 Molecular Weight Critical Temperature- C Boiling Point- C Vapor Pressure at 20 C-kg/m 2 5.1< Critical Pressure-bar Liquid Viscosity- cP Liquid Density at 20 C-kg/m Bulk Modulus (N/m 2 )6.37E E+09 Specific Density,gas Solubility in H 2 O at 20 C g/l 70Negligible.12 Lower Heating Value- kJ/kg Heat of vaporization- kJ/kg 20 C Explosion limit in air- vol% Ignition temperature at 1 atm- C Cetane Number

88 Factors Driving DME Fuels Growth – Diesel Substitution Opportunities Can be used in conventional diesel engines with a modified fuel injection system Large potential market High cetane Quiet combustion Clean burning (sootless – no smoke or particulates) 100% SOx reduction Challenges Technical and regulatory hurdles remain LPG-like distribution infrastructure Lower lubricity requires lubricating agent Lower viscosity can cause leakage Government regulations Volvo DME Truck

99 Factors Driving DME Fuels Growth – Diesel Substitution Isuzu DME Diesel TruckNissan NTSL DME Diesel Truck SAIC DME Diesel Bus Volvo DME Diesel Engine Much Work Underway Japan DME Vehicle Promotion Committee Volvo & BioDME Consortium Shanghai Automotive Corp. Alternative Engine Technology Isuzu Advanced Engineering Center Nissan SAIC DME Diesel Engine

The Energy InstituteEMS Energy Institute Developer of Novel Fuel Injection Systems for DME AFT fuel system technology is being adapted for commercial heavy duty applications by Volvo Group and Delphi AFT fuel system can be scaled from light- duty to heavy-duty applications Developer of Novel Fuel Injection Systems for DME AFT fuel system technology is being adapted for commercial heavy duty applications by Volvo Group and Delphi AFT fuel system can be scaled from light- duty to heavy-duty applications Technology Description Developer of Fleet Scale DME Production System DME at gallons per day Natural Gas and CO 2 as feedstocks Leaps over the Valley of Death due to small scale production Developer of Fleet Scale DME Production System DME at gallons per day Natural Gas and CO 2 as feedstocks Leaps over the Valley of Death due to small scale production R&D Support and Technology Demonstration Transportation Institute / Test Track / Chassis Dyno Combustion, Emissions and Fuel Formulation R&D Support and Technology Demonstration Transportation Institute / Test Track / Chassis Dyno Combustion, Emissions and Fuel Formulation

Oberon Fuels Process Biogas Natural Gas + CO 2 Syngas DME Methanol Gas-to-Liquids Unit NG-DME Bio-DME

Technology 30% CO2 in feedstock and scale are well suited for distributed waste biogas sources Innovations from Oberon focus on: –Integration of modular components –Process efficiency –Centralized volume construction Utilize proven components and catalysts Benefit from the development of small-scale hydrogen production units

World leader in DME fuel system innovation – developed four generations of common rail fuel systems specifically designed for DME Novel fuel pumps and fuel injectors Novel fuel feed pump to send fuel from the supply tank to the engine

The Energy InstituteEMS Energy Institute Because it makes sense on many levels: Higher energy density than compressed natural gas Will not vent due to evaporation over time Does not need cryogenic storage Ease of refueling (no venting, no compressors) Diesel engine efficiency Ultra low emissions with simple emissions controls Monetizes dry gas in the Marcellus Shale Natural gas is selling at less than $2.50 per equivalent diesel gallon (Jan. 2012, DOE Clean Cities Alternative Fuel Price Report January 2012 DME is anticipated to sell at $3 per equivalent diesel gallon Represents an increase in the value of the natural gas Because it makes sense on many levels: Higher energy density than compressed natural gas Will not vent due to evaporation over time Does not need cryogenic storage Ease of refueling (no venting, no compressors) Diesel engine efficiency Ultra low emissions with simple emissions controls Monetizes dry gas in the Marcellus Shale Natural gas is selling at less than $2.50 per equivalent diesel gallon (Jan. 2012, DOE Clean Cities Alternative Fuel Price Report January 2012 DME is anticipated to sell at $3 per equivalent diesel gallon Represents an increase in the value of the natural gas Why Consider DME? This team has the capability to bring DME and DME engines to market cost-effectively