Post on 03-Apr-2020
PennStateDept. of Chemical Engineering113 Fenske LabUniversity Park, PA 16802
Goal: Quantify and characterize fuel system interactions and
elastomer compatibility with dimethyl ether
Performance Cost
Ease of UseEngine Compatibility
Without sacrificing
Dr. Kimberly WainDr. Joseph PerezDr. Wallis Lloyd
Alternative FuelsDimethyl Ether Rheology and Materials Studies
How much petroleum is the world consuming? According to DOE…
N. America
Western Europe &AustrailaEurasia
Central & S.AmericaAfrica
Middle East
Other1.85% of worldoil in US
Where is the world’s oil located?(proven reserves)
US has extremely limited proven oil reserves, imports
Developing countries will require massive resources
Petroleum Outlook
Million barrels per day
DevelopingAsia
OtherDeveloping
0
10
20
30
40
OtherIndustrialized
Nations
NorthAmerica
EE/FSU
U.S. Diesel Emissions Regulations
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 2 4 6 8 10 12
NOx Emissions (g/bhp*hr)
Parti
cula
te M
atte
r (g/
bhp*
hr)
1984
19881990
1991
1994199820042007
Trade off- reducing NOx, usually increases PM
To achieve emission goals:
Combustion designAfter-treatment systems
Electronic controlsAlternative fuels
S and P in fuel(also regulated)
catalyst poisons!
Combo
Fuel Studies at PSU
Diesel Fuels
Biodiesel Fuels
Dimethyl Ether
+ ROH catalyst
Hydrocarbon Syngas DME
Distillation Hydrocarbon mixture
Soybeans
Petroleum cut boiling ~282-338oC
LSDF 325 ppm SULSDF < 15 ppm S
Blends of methyl esters made from vegetable oils- renewable!No sulfur, phosphorus content
Converted biomass- renewable!Zero emission fuel, gas at STP
Viscosity Improvement
Raise to ASTM lower limit(DME)
Elastomer Durability
Fuel Injector Lubrication
Mimic fuel injector response
How alternative fuelseffect physical properties
DME Areas Investigated
Viscometry
Pressurizable design
Small capillary for enhanced accuracy
Adaptable Swagelock® fitting at fill port
Test Matrix
Typical viscosity improving additivesEnvironmentally friendly additives
Blends of DME and diesel- with and without additivesBlends of DME and biodiesel- with and without additives
Principle: Time for a certain volume of liquid tomove through a calibrated capillary
VLHtgD
12810 46πυ =
Viscometer Data
0.00
1.00
2.00
3.00
4.00
5.00
6.00
0 20 40 60 80 100wt % DME
Visc
osity
(cSt
)
ULSDF 25CULSDF 40CBiodiesel 25CBiodiesel 40C 4.1 cSt
1.9 cSt
ASTM #2 Diesel Viscosity Specs. at 40oC
Dramatic decrease in viscosity with addition of DME in small quantities
Two temps so responsecan be extrapolated
TraditionalPolymethacrylate- Long chain ester (OFM, VI)
Olefin Copolymer- Ethylene/propylene non-conjugated diene (VI)
Alcohol- Ethoxylated long chains (OFM)
Synthetic
Poly-a-olefin- PAO-40 “40” refers to kinematic viscosity at 100 oC (VI)
Environmentally Friendly
Vegetable Oil- Heat modified (polymerized) soybean oil (OFM)Vegetable Oil- Mixed fatty acids (OFM, VI)Vegetable Oil- Oleic acid alternative (OFM, VI)
Additives Used
Additive Effect
1 and 5 wt % concentrations tested in 25 wt % DME
0.0
1.0
2.0
3.0
4.0
5.0
6.0
40
Temperature (oC)
Vis
cosi
ty (c
St)
25% DME-ULSDF 25% DME-Biodiesel1% PMA ULSDF 5% PMA ULSDF1% PMA Biodiesel 5% PMA Biodiesel1% OCP ULSDF 5% OCP ULSDF1% OCP Biodiesel 5% OCP Biodiesel1% Ethoxy ULSDF 5% Ethoxy ULSDF1% Ethoxy Biodiesel 5% Ethoxy Biodiesel1% HEAR Oil ULSDF 5% HEAR Oil ULSDF1% HEAR Oil Biodiesel 5% HEAR Oil Biodiesel1% PAO-40 ULSDF 5% PAO-40 ULSDF1% PAO-40 Biodiesel 5% PAO-40 Biodiesel1% Mixed FAs ULSDF 5% Mixed FAs ULSDF1% Mixed FAs Bio 5% Mixed FAs Bio1% HT Soy ULSDF 5% HT Soy ULSDF1% HT Soy Bio 5% HT Soy Bio
ASTM #2 Diesel Viscosity Specs. at 40oC
4.1 cSt
1.9 cSt
Material Compatibility
Elastomer Durability
Chosen materials represent major types commercially available:
Buna-nSiliconViton
PolyurethaneTeflon
Kalrez (fluoro-polymer)
Expensive specialty polymer with high chemical resistance
ME tested 1) right out of pressure vessel and 2) after diffusion of DMout of o-ring (temporary versus permanent damage)
Buna-N Fuel Response
Strength loss is temporary and likely due to partial solvency of fuel in elastomer Extended exposure leads to performance compromise in DME
Kalrez Fuel Response
Strength loss is permanent and likely due to rupture of crosslinkingExtended exposure leads to deterioration in DME
Fuel Injector Wear
Bench Testing
Goal: Faster, less expensive test that accuratelypredicts fuel injector behavior
Modified Cameron-Plint wear tester
Pressurizable housing
Utilizes parts duplicating actual injector parts:- Same geometry as diesel injector- Same surface roughness and materials- Operates at typical or higher frequency
Total costs per test: ~$250 vs. $5000 for full engine testTotal operational time: 3 hrs. vs. weeks for engine test
Significant savings!
Cameron-Plint Device
Test Pins
Modified Cameron-Plint
Variable speed motor, 0-50 Hz
Fully simulates injector motion
Matching outer cylinder per pin
Capable of 2 tests /cylinder 1 per pin
New
DMEDME-
Scuffed
Fuel Injector Pin
Pin travel distance: 1mm
Wear Scar Mapping
MicroXAM™ Surface Mapping Microscope
Wave/light interference generates a horizontal light plane which is used as a surface probe
Successive intersections between the probe plane and the sample are the relief level curves
Pros: Fast image acquisition Easy to useRobust technique
Cons: Res. limit ½ wavelength of light sourceCurvature problematic
Wear Scar Examples
75 wt % DME/25 wt % ULSDF
Scar flattened, curvature removed
Wear Area
Depth of scar α severity of wear
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
0 500 1000 1500 2000 2500 3000
Length Position (mm)
Surfa
ce H
eigh
t (m
m)
Data confirms trend of incr. wear with incr. [DME]
Unworn height
Discrimination between ULSDF and biodiesel blends possible
0.000
0.200
0.400
0.600
0.800
1.000
1.200
1.400
1.600
1.800
0 20 40 60 80Wt % DME
Tota
l Wea
r Dep
th (
m)LSDFULSDFBiodiesel70 wt % Bio/5 wt % PMA70 wt % ULSDF/5 wt % PMA
Increasing wear scar depth with increasing [DME]Additives caused deeper scar: cycled fuel mixture=shearing of additives
chemical corrosion; 3 body wear
3 hours40 Hz150psi HeStatic test fluid
Cameron-Plint Data
Summary
Viscosity Material Compatibility
Fuel Injector Wear
Alternative Diesel Fuel Understanding
Acknowledgments
The Pennsylvania State UniversityDept. Of Chemical Engineering
113 Fenske Lab(814) 863-4537
Funding provided by:
Air Products Inc.C & K Technologies, Ltd
Caterpillar Inc.Dept. of Energy
National Science Foundation
Technical Support:
Argonne Nat’l LabUSDA Labs, PeoriaBritish PetroleumCannon Instr. Co.
Contributors:
Don Stiver, PSUDr. Bob Manning, Consultant
CAPTAIN – Is Port Left or Right?
THANKS - CAPTAIN JOHN