Post on 31-Mar-2015
transcript
The Energy InstituteEMS Energy Institute
Dimethyl Ether - A Path to Use Natural Gas as a Transportation Fuel
Dimethyl Ether - A Path to Use Natural Gas as a Transportation Fuel
André BoehmanEMS Energy Institute
Department of Energy & Mineral Engineering
The Pennsylvania State University
Partners:
Oberon Fuels
Alternative Fuel Technology, LLC
André BoehmanEMS 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 Won’t 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 Won’t boil off if your vehicle sits for two weeks
Why Consider DME?Why Consider DME?
The Energy InstituteEMS Energy Institute
J. Eberhardt, DEER 2002
DME 61% the energy contentof propane
Similar energy contentto ethanol on volume basis
The Energy InstituteEMS Energy Institute
Vehicle Cycle THC (g/mi) NMHC (g/mi)
NOx (g/mi)
CO (g/mi) CO2 (g/mi)
PM (g/mi)
Btu/mi
RTD Bus 1014-CNG CBD 20.04 2.19 9.06 0.34 1690 0.02 27018
RTD Bus 1011-Diesel
CBD 0.18 ----- 16.12 11.18 1785 1.02 22908
Comparison of Emissions of Low Emissions Vehicle-Certified RTD Buses
McCormick, Graboski, Alleman, Herring and Nelson, SAE 1999-01-1507
CNG Vehicles Suffer From: Reduced compression ratio lower thermal efficiency
High unburned CH4 emissions
Combination of high CH4 emissions and reduced efficiency eliminates the H/C ratio benefit of CNG over diesel fuel with respect to CO2eq emissions
CNG Vehicles Suffer From: Reduced compression ratio lower thermal efficiency
High unburned CH4 emissions
Combination of high CH4 emissions and reduced efficiency eliminates the H/C ratio benefit of CNG over diesel fuel with respect to CO2eq emissions
~ 1890 g/mi at 10*GWP of CH4~ 2090 g/mi at 20*GWP of CH4~ 3090 g/mi at 70*GWP of CH4
The Energy InstituteEMS Energy Institute
1990’s: Thomas and Staunton (SAE 1999-01-1511) 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.
Weaver and Turner (SAE 940548) 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.
1990’s: Thomas and Staunton (SAE 1999-01-1511) 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.
Weaver and Turner (SAE 940548) 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 EfficiencyCNG Vehicle Efficiency
Can we “burn” natural gas and have diesel or better efficiency? consider DME
Patron member
Patron member
Dimethyl-ether(DME)
Methane
Methanol
Water
Propane
Butane
Hydrogen Carbon Oxygen
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
Property DME Diesel Propane
Chemical Formula C2H6O C10.8 H18.7 C3H8
Molecular Weight 46.07 148.6 44.11
Critical Temperature- C 127 - 95.6
Boiling Point- C -24.9 71-193 -42.1
Vapor Pressure at 20 C-kg/m2 5.1 <0.01 8.4
Critical Pressure-bar 53.7 - 43
Liquid Viscosity- cP .15 2-4 .10
Liquid Density at 20 C-kg/m3 668 800-840 501
Bulk Modulus (N/m2) 6.37E+08 1.49E+09
Specific Density,gas 1.59 - 1.52
Solubility in H2O at 20 C g/l 70 Negligible .12
Lower Heating Value- kJ/kg 28430 42500 46360
Heat of vaporization- kJ/kg 20C 410 233 426
Explosion limit in air- vol% 3.4-17 1.0-6.0 2.1-9.4
Ignition temperature at 1 atm- C 235 250 470
Cetane Number 55-60 40-55 -
7
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 Truck Nissan 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 DescriptionTechnology Description
Developer of Fleet Scale DME Production System DME at 3000-5000 gallons per day
Natural Gas and CO2 as feedstocks
Leaps over the “Valley of Death” due to small scale production
Developer of Fleet Scale DME Production System DME at 3000-5000 gallons per day
Natural Gas and CO2 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 + CO2
Syngas DMEMethanol
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 injectorsNovel 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?Why Consider DME?
This team has the capability to bring DME and DME engines to market cost-effectively