Biodiesel Technical Training Course

BIO 3.0Biodiesel Engine Performance and

Vehicle Maintenance

Provide comprehensive training seminar about biodiesel engine and emissions research, especially with newer PM traps and NOx aftertreatment

Provide technical instruction on biodiesel’s impact towards engine performance and vehicle maintenance

Provide access to industry experts for more detailed questions and answers about biodiesel

Introduce the National Biodiesel Board’s Diesel Technician Training program and the program resources to the audience

Learning Objectives

Be able to answer general questions about biodiesel that you may be asked as a technician

Be able to explain biodiesel impact on PM traps and NOx aftertreatment

Be able to properly diagnose and make recommendations regarding biodiesel use and vehicle maintenance

Learning Outcomes

Ford F-250 Super Duty Sets Two Land Speed Records

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Biodiesel Land Speed Record Video

Key Resources

Biodiesel Delivers Important Diesel Properties

Auto-ignition = Cetane Number over 50 BTU Content = Similar to #1, less than #2 Viscosity = Values in diesel fuel range (1.9 to 6.0) Cloud Point = Current biodiesel higher than #2 Lubricity = Naturally high in lubricity, typical values less

than 300 Sulfur = Naturally less than 15 ppm Cleanliness = ASTM specs same as petrodiesel Stability = Spec set for 6 month minimum shelf life Emissions significantly less for PM, HC, CO

Long Term Durability Information

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Cummins B20 Durability StudyThe objective was to operate the engine for 1000 hr. using B20 biodiesel

fuel, and do a comparative analysis with engines that have operated under the same type of conditions using #2D diesel fuel.

hr

0 25 50 125 1000

Accelerated, high-load durability cycle

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• Cummins prototype 2007 ISL, Six cylinder 8.9 liter• Rated power of 330 BHP, Peak torque of 1150 ft•lb at 1300 rpm• Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF)• Variable geometry turbocharger, Exhaust gas recirculation (EGR) with cooler, Cummins fuel injection

system

Durability & Emission Results

• Approximately 17,000 gallons of B20 biodiesel fuel was used during the durability test.

• Test went well and was successful. There were no biodiesel related failures during the test, and no reported significant changes in performance of the engine.

• Engine performance was essentially the same when tested at 125 & 1000 hr. of accumulated durability operation.

• Emission results indicate that THC, CO, and PM levels were not significantly different between the B20 and ULSD. • The emission-grade B20 test resulted in slightly higher NOx

(within expected range)• Fuel consumption was observed to be ≈3% higher than the 2007

certified ULSD test (within expected range).

Top of cylinder head No sludge deposits

Bottom of cylinder head Deposits comparable to #2D

Intake Valves Exhaust Valves

Results are typical for this type of test with #2D diesel fuel

Overhead Components

Power Cylinder Components

Component Comments

Piston Normal light wear and deposits.

Cylinder Liners Normal light wear.

Top rings Normal uniform face wear. Top and bottom side look typical.

Middle rings Normal face wear. Top and bottom sides OK, and light carboning.

Oil rings Looked good. Very little wear.

Crosshatch visible in all six cylinders.

Results comparable to #2D diesel fuel test.

Ring GroovesAnti-Thrust Side

Cylinder 1

Top PistonPiston Bowl Front

Cylinder 1

Minor staining

Aftertreatment Components

Component Comments

Diesel Oxidation Catalyst (DOC)

Looked good. No face plugging.Blockages found appeared like debris and substrate material. Debris was analyzed under Electron Dispersive Spectroscopy (EDS), and all debris found is expected in a typical DOC after 1000 hr of operation, whether fueled with ULSD or biodiesel.

Diesel Particulate Filter (DPF)

Inlet face showed signs of ash build up, but similar to diesel fuel for this type of test. Outlet looked good with no signs of soot.No failure found.

Inlet and outlet section

Looked good.

Gaskets Looked good.

Fuel System Pictures

Stage 1 Plunger Needle

No marks on needle surface or the edge.

Plunger Needle – Top View

Some slight staining.

Stage 2 Plunger Needle has some wear, but normal for this type of aggressive test.

Plunger Orifice not clogged with oil

sludge or deposits

Fuel System ComponentsRail and fuel lines Rail – No abnormal wear.

End Fitting – No unusual wear. HP Fuel Lines – No visible structural deterioration or cracks observed.

Mechanical Dump Valve (MDV)

No unusual wear, deterioration or sludge buildup observed on plungers, plunger seats or orifice.1) Stage One Plunger – No wear visible on the needle surface or the edge. Some slight staining seen on plunger base.2) Stage Two Plunger – Some wear, but normal. Plunger orifice not clogged with oil sludge or deposits.

Injectors Injector performance test and photos indicate that the injectors were consistent with injectors that ran with #2D diesel fuel.

Soft Lines No visible damage to any section of the internal wall of the used fuel tubes indicating that the tubing liner material is resistant to the B20 temperatures and pressures during the engine performance test.

Overall There were no signs of severe or aggressive corrosion pitting damage on any of the surfaces.

Cummins Durability Summary• A Cummins 2007 prototype 8.9 liter ISL diesel engine equipped with DOC, DPF, VGT, and

EGR with cooler was operated successfully at SwRI using a high-load accelerated durability cycle for 1000 hr. with a B20 blend of soy-based biodiesel and ULSD.

• During the durability testing, no biodiesel related failures occurred.

• Engine performance was essentially the same when tested at 125 and 1000 hr. of accumulated durability operation. Emissions measurements indicate the HC, CO, and PM were not significantly different between the B20 and ULSD tests, and NOx increased with B20 fuel. Fuel consumption also increased with B20 fuel.

• A thorough engine teardown evaluation of the overhead, power transfer, cylinder, cooling, lube, air handling, gaskets, aftertreatment, and fuel system parts was performed.

• There were no failures found on the engine components that were directly attributable to running biodiesel B20.

• The wear and deposits found were normal and consistent with findings from parts that ran with #2 diesel fuel in similar tests.

Maintenance and Servicing

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Using Over B20

o Material compatibility is key for blends above B20o Repair Fuel leaks to prevent impact to other systems

From the fuel sending unit in tank to injectorsPrimary & secondary fuel filtersFuel lines (sending & return)High pressure or low pressure injectorsO-ringsTransfer & injection pumps

Biodiesel only contacts the fuel system so use should not affect bearings, turbo, oil/water pumps, and other wear-related parts.

Service Intervals with Biodiesel Follow OEM Service Intervals with B20 and lower blends Cummins and John Deere: “half the standard interval for the next two fuel filter changes… Afterwards, revert to the intervals specified in O & M manual.”

Refer to OEM recommendations

B20 User Troubleshooting & Maintenance Checklist

ASTM Specs – Make sure your supplier provides ASTM quality

Microbial Growth – Eliminate free water in fuel storage

Black Fuel Filters – Hot fuel return to fuel tank, happens with diesel or B20 with some HPCR

Waxy, clogged fuel filters:Raw vegetable oil or off spec Inappropriate fuel cold flow

properties of finished blend:Contact your supplier—they should

provide appropriate finished blends

Store Fuel in Clean, Dry Dark EnvironmentMonitor hoses, fill/vapor caps, gaskets for leaks w/ blends over B20 Work with your supplier or consider monitoring program or stability additives if storing fuel longer than 6 month.Conduct normal filter maintenanceBe aware of cleaning effect, 2% of the time filters may need to be changed when first switching to B20 until system is cleaned of previous diesel sediments and deposits

Emissions Data on New Aftertreatment

AARON WILLIAMS, AN ENGINEER WITH THE NATIONAL RENEWABLE ENERGY LABORATORY, TESTS A UREA SCR SYSTEM. PHOTO: NREL 20

Biodiesel’s Lower Emissions

2002: EPA, A Comprehensive Analysis of Biodiesel Impacts on Exhaust Emissions- suggested slight NOx increase with B20 using EPA diesel, heavily weighed on unmodified bus engines◦ Most early testing was on buses, a lead B20 market in

the 1990’s◦ Substantial decrease in all other emissions

2006: NREL, Effects of Biodiesel Blends on Vehicle Emissions: B20 has no statistically significant net impact on NOx emissions using EPA 49 state petrodiesel◦ Removal of 1992 bus engines which were no longer in

service

2002 EPA B20 Evaluation with EPA 49 state petrodiesel

U.S. biodiesel reduces lifecycle carbon emissions by over 50% compared to petrodiesel, qualifying it as an Advanced Biofuel under RFS-2 and making it the best carbon reduction tool of any liquid fuel commercially available.

Changing Diesel Fuel & Emissions standards

• Introduction of ultra-low sulfur diesel fuel in October 2006

• EPA emissions standard for 2007:

• Diesel particle filters (DPF)

• Increased levels of exhaust gas recirculation (EGR) and higher fuel injection pressures

• Full EPA emissions standard in 2010:

• DPF, EGR, high pressure fuel injection

• Exhaust catalysts for NOx reduction

• NOx adsorber catalysts, unburned diesel fuel for operation (not preferred)

• Selective catalytic reduction (SCR)--preferred

• Diesel Exhaust Fluid (DEF) needed for SCR operation

Average NOx Emissions: Various Cycles

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This chart is a rough summary of NOx emissions levels over various emissions cycles completed by NREL on buses using a chassis dynamometer from SAE paper 2012-01-1984. It shows the dramatically lower overall NOx levels as engine technology improves. 0

5

10

15

20

25

30

35

1998 2005 2008 2010

Average gram of NOx per mile

Diesel Particle Filters Exhaust flows through porous wall-flow elements

◦ PM is trapped on the walls of the filter When exhaust temperature is high enough, PM is burned off

◦ In most cases, unburned diesel fuel is injected to accomplish this Precious metal is loaded onto filter walls to lower the temperature

required for regeneration Issues:

◦ Regeneration at low temperatures/duty cycles◦ Plugging with incombustible materials like lube oil ash

DPF: Balance Point Temp - Regeneration Rate

ResuSuperb Resultslts

BPTULSD

360ºCB20

320ºCB100

250ºC

•BPT is 40ºC lower for B20•Soot is more easily burned off of filter•B20: lower temperature duty cycle is OK

• Regeneration rate increases with increasing biodiesel content

• Even at 5%, biodiesel PM measurably oxidizes more quickly

DPF Regeneration

NOx Controls NOx Adsorber Catalyst/Lean NOx trap

◦ Catalyst converts all NOx to NO2, adsorbent bed “traps” NO2

◦ When bed is saturated, exhaust forced rich◦ NO2 is released and converted to N2◦ Bed also traps SO2, but doesn’t release it◦ Near sulfur free exhaust is needed◦ Higher temps, longer time needed to release sulfur◦ 90%+ conversion is possible

Selective Catalytic Reduction (SCR)◦ Used for industrial NOx control for years◦ Requires a supplemental “reductant”◦ Typically ammonia, derived from urea◦ “Diesel Exhaust Fluid”◦ 80-90% reduction efficiency◦ Generally sulfur tolerant

NOx adsorber catalyst (NAC) is also known as a lean-NOx trap (LNT)

SCR

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Biodiesel Testing Cummins ISB 300 2002 Engine, 2004 Certification Cooled EGR, VGT Johnson Matthey CCRT 12 Liter DPF Passively Regenerated System Pre Catalyst (NO2 Production)

Fuels: ULSD, B100, B20, B5

ReFUEL Test Facility 400 HP Dynamometer Transient & Steady State Testing Cummins Soot Characterization Significant financial support for

testing

Biodiesel Testing with LD Emission Systems

Includes two emission control systems and two fuel blends on a light-duty platform

◦ NAC/DPF and SCR/DPF◦ 5% and 20 % biodiesel blends

Performance, optimization and durability◦ Aging to represent 2100 hours of operation (approximately 120,00 miles or full

useful life) for B20◦ Emissions evaluations over UDDS, US06, and HFET– testing by EPA◦ Perform engine and fuel component teardown at end of aging

Engine: DCX OM646

Vehicle: Mercedes C200 CDI

EPA Chassis DynamometerNOx Adsorber Catalyst (NAC)

B20

ULSD

Experimental: SCR

Urea Injection

Diesel Particulate Filter

DOCSelective Catalytic Reduction

NH3 Slip Cat

Diesel Particulate Filter JM CCRT (12 Liters) Passively Regenerated Pre Catalyst for NO2

Production

Compare SCR catalyst performance with ULSD and Soy B20 through engine testing

Measure relative importance of catalyst temp, exhaust chemistry and catalyst space velocity

Measure B20’s impact on these system variables and overall NOx conversion

Focus on Steady-State Modal Testing

de-NOx Aftertreatment JM Zeolite SCR (15.5 Liters) Urea Injection (air assisted) NH3 Slip Catalyst

Diesel Engine 2002 Cummins ISB (300 hp) 2004 Emissions Cert Cooled EGR, VGT, HPCR

ULSD vs B20 – SCR

No statistical difference in NOx Conversion with B20

SAE 2012-01-1984

Figure 10 - NOx emissions from a 2010 transit bus..

SAE 2012-01-1984

Figure 11 - NOx emissions from a 2011 transit bus.

Lubrication Oil and B20 All older and newer DPF equipped engines:

◦ Change oil as recommended by Engine manufacturer◦ Use OEM recommended engine oil with correct API, CI rating◦ Regular oil analysis maintenance program◦ Look for any other special recommendations by the OEM

DPF equipped passenger car engines with in-cylinder post injection for DPF regeneration, primarily 2009+◦ Possible for slightly more B20 to reach cylinder wall where fuel can be pulled

into the crankcase by the normal scraping action of the piston's oil control rings.

◦ Due to high boiling point of biodiesel, the fuel that reaches the crankcase is slower to vaporize and remove itself from the engine oil pan

◦ Inspect dipstick for biodiesel smell or increasing oil levels◦ Change oil if the level is increasing

B20 and After-Treatment SystemsBiodiesel is compatible with Diesel Particulate Filters and NOx SCR systems, and has some distinct advantages:

Less engine out particulate matter Particulate burns off faster and at lower temperatures May provide better performance and decreased maintenance vs. ULSD

alone May make some systems passive vs. active Potential increase in fuel economy

For active regeneration, mode of fuel delivery to trap is important i.e. in-cylinder vs. exhaust stream

Most US heavy duty applications use exhaust stream fuel injection which is compatible with B20, perhaps higher blends

Some light duty foreign OEMs recommend max B5 at present, but NBB is working with them to get them to B20.

Same 90% + reduction in NOx using NOx SCR after-treatment

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B20 vs. Diesel: In the shop

With in-spec B20 and lower, the issues you can expect to see in your shop are the same as you will see with petrodiesel Except:

◦Expect to see less lubricity related issues◦Research indicates less problems with after-treatment◦Filter related issues may be related to cleaning effect upon first use, or are likely normal diesel issues or out of spec or imposter biodiesel

◦Less black smoke from exhaust!

Biodiesel Resourceswww.biodiesel.org

• Biodiesel Training Toolkit

• News Releases & Information Resources

• Technical Library, Spec Sheets & Videos

• OEM Warranty Positions on Biodiesel

• U.S. Diesel Vehicle List

www.BQ-9000.org • Listing of BQ-9000 Certified Companies

www.biotrucker.com• Listing of BioTrucker retail sites

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