From the field experience, you can see that with fuel meeting the specifications, and a few simple precautions, users have a good experience with B20—maybe changing fuel filters initially, maybe a few more cold weather issues, but all of which can be handled by following the appropriate the guidelines. So we will review some of the lab experience related to biodiesel performance, and some examples of some pretty significant work that’s been done in cooperation with the engine companies, in terms of lab durability studies, both with engine durabilities and with engine oil impacts. The first of these will be with engine oil impacts.
One of the reasons for that is some of the durability runs that had been done on B20 in existing engines. It’s fairly typical for an engine company to run durability runs with diesel fuel to make sure the engines they put out are going to perform well in the field over time. They do that with an accelerated program plan, and in this case, Cummins ran a 1000 hour durability on B20, with the objective to operate the engine for 1000 hours using B20 fuel and do a comprehensive analysis of the engine that had operated on the fuel with the same type of conditions that they would use for No. 2 diesel fuel. You see the test plan here, looking at 1000 hour test plan, 125 hours of initial break-in, measuring emissions, and then running the engine for another 875 hours for a total 1000 hours. Then they run the emissions again to see how the emissions of the engine might have changed throughout its useful life. Most of the time, the engine is run on an accelerated high load durability cycle to stress the engine out again, stressing the engine as much as possible to gain maximum potential negative effects, should there be any on the engine.
The test engine used was a Cummins prototype 2007 ISL engine, six cylinder, 8.9 liter with 330 brake horsepower at 1150 ft lb of torque at 1300 rpm. It was outfitted with a diesel oxidation catalyst and a diesel particulate filter. That filter used the in-cylinder post injection for active regeneration. It had variable geometry turbocharging, exhaust gas recirculation with an inner cooler, and the Cummins proprietary fuel injection system. So it really had the latest bells and whistles on a prototype engine with both EGR and a diesel particulate filter. There were no NOx controls on this particular engine.
The test cycle that was used had about 70% of the durability cycles at full load, so it accelerates through high load in a transient cycle, it varies the load and speed, and then it repeats those cycles anywhere from peak torque power to high idle to low idle to peak torque, and goes through that cycle over 1000 hours. The emissions testing that was done was according to the Federal Test Procedure. One cold start transient FTP test and then three hot starts, and then one set of Ramped Modal Cycle.
The results for that engine are shown on this slide. Approximately 17,000 gallons of B20 was used during the test. The test went well and was successful. There were no biodiesel related failures during the test, no reported significant changes in performance of the engine. The engine performance was essentially the same when it was tested at 125 hours and at 1000 hours after the accumulated durability operation. The emissions results indicated that the hydrocarbon, CO and PM levels were not significantly different between the B20 and the ULSD in this particular test. We do see PM, CO and hydrocarbon levels on non particulate trapped engines, but with the particulate trap, the B20 didn’t provide that much more than the ULSD alone did. On the emissions also, the B20 was slightly higher in NOx, but is within the range that we expected to see for this particular test cycle and this particular engine. We may see lower NOx, in other applications or if a chassis dyno was used rather than an engine dynomometer. The fuel consumption was observed to be about 3% higher than the 2007 certified ULSD, which was within the expected range. That is about the expected range of the BTU content of the biodiesel.
Here are some pictures of the components. We see the top cylinder heads had no sludge deposits. Deposits were comparable on the bottom of the cylinder head between diesel fuel and No. 2 diesel fuel. Both the intake and exhaust valves were typical for this type of test run on conventional No. 2 diesel.
For the power transfer components, the crank shaft was in very good condition, with the results comparable to No. 2 diesel fuel, and at least in this particular case, no adverse impacts on any of the engine oil related areas. All of the components from the crank shaft gear to the cam bearing to the bushings, fuel pump gears, connecting rods, etc all looked normal and meet the traditional rebuild specs that we would expect for this engine operating that long.
The power cylinder components—the crosshatch was still visible on all six cylinders, the ring grooves similar, the top of the pistons similar.
Everything looked normal, and the same situation with the cooling and the lube components. No issues, no problems, just all around a clean bill of health.
The same with the air handling components. There was a little bit of soot in some areas, but in the areas where there was soot, we would expect that with normal diesel fuel as well. So nothing out of the ordinary.
The aftertreatment components—this was something that was of interest, because one of the questions was whether or not it would have an impact on aftertreatment, and in this particular test, the diesel oxidation catalyst looked good. There were some blockages found, but that’s normal for what we’d expect with diesel fuel. On the diesel particulate filter, and this was one of the runs with the diesel particulate filter after 1000 hours of operation, that looked good. And the gaskets looked good, as well as the inlet and outlet section.
Here you see some pictures of injectors, plungers, etc. No issues to note there.
The other fuels system components had no issues noted there either.
In summary with this engine, it was a Cummins 2007 prototype with a particulate trap that was in-cylinder post injection for control with EGR and variable turbo charging, was operated successfully. No biodiesel related failures, engine performance with the same, emissions were the same. A thorough engine teardown analyzed pretty much all the parts that we could look at, and there were no failures related to B20, and the wear and deposits were consistent with what we’d see with diesel fuel. So a good bill of health, and really show that the ASTM specs and for biodiesel meeting those specs, even in this new prototype engine, is going to perform well for users in the fuel system.
Most of you have seen this slide, which discloses the various technologies that are being applied to achieve Tier 2-4 emissions levels. I will only discuss the fuel system where the migration to common rail systems are a key leverage for achieving low emissions.
This slide has both petrodiesel and biodiesel in its title because many of the issues associated with biodiesel filter clogging really aren’t biodiesel related at all. There are some that are related to biodiesel—or out of spec biodiesel—but its important for you as a diesel technician to know the difference so you can provide good advice back to your customers.
Air enters all diesel systems and most of that time the air that comes in bring moisture with it. Air and moisture are the enemies of any fuel system—whether that system is petrodiesel or biodiesel. The presence of air will increase oxidation of the fuel over time. The best thing to do to minimize oxidation is to have good turn over of the fuel and not to store if for long periods of time. Most fueling systems do this as part of normal business, so it doesn’t end up being a problem. If there are systems where the fuel might stay around, fuel stabilizers are recommended as are desiccant dryers on the air vents which will minimize the potential for moisture contamination.
Micro-organisms have been found in diesel fuel forever, and seem to be an increasing issue since the advent of ultra low sulfur diesel fuel. They grow at the water interface at the bottom of the tank, living in the water but feeding off of the fuel—whether that is petrodiesel or biodiesel or a biodiesel blend. If micro-organisms are present in a high enough quantity they can clog a fuel filter. They are relatively easily treated with a variety of conventional biocides which kill the organisms which can then be filtered out. Keeping the water out of tanks on a regular basis can go a long way toward reducing or eliminating micro-organisms. Filters with microbial growth appear black and slimy and typically have an odor different that is normal. There are a variety of microbial testing kits that users can buy to see if their fuel is starting to grow bugs. Its not desirable to regularly treat for bugs unless you actually have them, since you don’t want the bugs to develop a resistance to the biocide.
The issue of water contamination is one that is poorly understood with biodiesel and biodiesel blends. This is primarily because of the issues with ethanol being water loving and people just automatically believe the same issues with ethanol exist with biodiesel. Pure biodiesel, B100, can hold slightly more water than diesel fuel—about 1200 ppm vs. 300 ppm) but even that is still a very, very small amount of water (0.12%) and is virtually the same as the amount of water gasoline holds (about 0.1%). In fact, biodiesel processors use the fact that water settles out of biodiesel, as many utilize a water wash step to helps to remove soaps and catalyst from B100. Data from NREL shows that B20 blends have similar water saturation characteristics as does petrodiesel alone. Both petrodiesel and B20 (or lower blends) hold somewhere between 100 and 300 ppm of water, with any more than that settling to the bottom of the tank. Keeping water out of tanks is always a good idea, and a good preventative maintenance program of checking tanks for water and if found removing that water is always a good idea for both petrodiesel and biodiesel.
Reading of the bullets is sufficient here.
Reading of the bullets is sufficient here.
Here are some examples of sediment or Rust build up.
Reading of the slides is sufficient here.
Here are some examples of filters with paraffin wax.
Reading the slides is sufficient here.
Reading the slides is sufficient here.
Reading the slides is sufficient.
Here is an example of a filter that was clogged with out of spec biodiesel—saturated monoglycerides.
You can use this handy checklist in the shop if you have filters coming in from the field and the user thinks it is a biodiesel problem. More than likely its not a biodiesel problem!
Advise your customers of these simple steps which will help maintain high quality fuel and minimize filter clogging.
To summarize, biodiesel and biodiesel blends are compatible with diesel particulate filters—and biodiesel provides some distinct advantages compared to petrodiesel alone (read bullets directly). There is one feature which is in the process of being investigated with some of the new particulate trap engine that technicians should be aware of. That feature is how the raw fuel is injected into the system to provide the fuel needed to burn the particles off the PM trap. There are two means to do this. The first way, which is used on most of the new PM trap equipped medium and heavy duty machinery in the US, is through a small fuel nozzle in the exhaust stream right before the particulate trap. Biodiesel blends—including pure biodiesel—work well with these systems. The second way is to use the injectors in the engine to vaporize raw fuel after combustion and during the exhaust stroke. This is called in-cylinder post combustion injection. Injection in this mode saves a fuel nozzle, but it creates more of an opportunity for fuel to hit the cylinder walls and get washed into the engine oil sump by the piston rings. This happens with petrodiesel alone, and the presence of biodiesel may make it a bit worse. Cummins did not identify this as an issue with B20 in the 1000 hour durability run on the prototype engine, and Ford doesn’t see this as an issues with their new engine, but some light duty car makers say blends over B5 are not recommended because of it. The jury is still out on this particular issue, but if it does happen you will see the level of oil on the dipstick actually go higher over time and if it goes too high that could cause the sump to fill up and cause problems or lower the lubricating properties of the oil. This phenomenon may require more frequent oil changes for B20 blends, or watching the oil level more closely with those models that use in-cylinder post injection but at present it only appears to be newest foreign light duty models that are affected.
BIO3.0 Biodiesel Performance and Vehicle Maintenance
Biodiesel Technical Training Course BIO 3.0: Biodiesel Vehicle Maintenance and Performance Presented by the National Biodiesel Board
National Biodiesel Board <ul><li>The National Biodiesel Board (NBB) is the trade association for the U.S. Biodiesel Industry </li></ul><ul><li>Receives funding from 3 sources: </li></ul><ul><ul><li>Soybean Check-off program (i.e. farmers) </li></ul></ul><ul><ul><li>Government Grants and programs </li></ul></ul><ul><ul><li>Biodiesel Producer contributions </li></ul></ul><ul><li>Technical, Regulatory, Marketing and Lobbying </li></ul><ul><li>Over $100MM over last 15 years </li></ul>
Today’s Topics <ul><li>Biodiesel Definition </li></ul><ul><li>Key Properties of Biodiesel </li></ul><ul><li>Fuel System, Air Intake, & Lubrication </li></ul><ul><li>Starting, Charging, Cooling, & Vacuum systems </li></ul><ul><li>Exhaust & Emissions Controls </li></ul><ul><li>Resources </li></ul>
Learning Objectives <ul><li>Provide access to industry experts for more detailed questions and answers about biodiesel </li></ul><ul><li>Introduce the National Biodiesel Board’s Diesel Technician Training program and the program resources to the audience </li></ul><ul><li>Provide technical instruction on biodiesel’s impact towards engine performance and vehicle maintenance </li></ul>
Learning Outcomes <ul><li>Be able to discern issues between normal diesel problems and poor quality biodiesel imposters or out-of-spec biodiesel when they hit the shop </li></ul><ul><li>Be able to properly diagnose and make recommendations regarding biodiesel use and vehicle maintenance </li></ul>
Biodiesel Defined <ul><li>Biodiesel , n. -- a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, meeting ASTM D 6751, designated B100. </li></ul><ul><li>Biodiesel Blend , n. -- a blend of biodiesel fuel with petroleum-based diesel fuel designated BXX, where XX is the volume percent of biodiesel. </li></ul><ul><ul><li>This tight definition was needed in order to secure vehicle, engine and fuel injection equipment company support for biodiesel, as well as to secure ASTM specs </li></ul></ul>
Biodiesel (B100) Attributes <ul><li>High Cetane (avg. over 50) </li></ul><ul><li>Ultra Low Sulfur (avg. ~ 2 ppm) </li></ul><ul><li>High Lubricity, even in blends as low as 1-2% </li></ul><ul><li>High Energy Balance (4.5 to 1) </li></ul><ul><li>Renewable, Sustainable, Domestically Produced </li></ul><ul><li>Increases overall fuel production capacity in USA </li></ul><ul><li>Reduces HC, PM, CO in existing diesel engines </li></ul>
Enhanced Lubricity <ul><li>Equipment benefits </li></ul><ul><ul><li>Superior lubricity </li></ul></ul><ul><ul><li>B2 has up to 66% more lubricity than #2 Diesel </li></ul></ul><ul><li>EPA required sulfur reduction in diesel </li></ul><ul><li>No overdosing concerns </li></ul>1-2% 66% Improvement
Cold Weather Performance <ul><li>Pure biodiesel does freeze faster than most petrodiesel </li></ul><ul><li>Your B20 supplier should provide blends of B20 that will not cause any cold flow issues in the winter </li></ul><ul><ul><li>Exactly the same way they do with #2 diesel fuel </li></ul></ul><ul><li>There are a variety of tools at the disposal of distributors to improve the cold flow operability of #2 petrodiesel and biodiesel blends </li></ul><ul><ul><li>Blending with #1, cold flow additives, etc. </li></ul></ul><ul><li>B20 has been used successfully in climates below -20 º F </li></ul>
Biodiesel Fuel Stability <ul><li>The biodiesel specification contains parameters for insuring adequate fuel stability for normal applications </li></ul><ul><li>The shelf life of biodiesel blends is recommended by NBB as 6 months </li></ul><ul><li>Stability additives available on the open market </li></ul>
Solvency Effect <ul><li>B20 & Under </li></ul><ul><li>Monitor filters, less than 2% need to be changed </li></ul><ul><li>Mild cleaning effect </li></ul><ul><li>Storage tanks may need to be cleaned, or keep extra filters on hand at start up </li></ul><ul><li>Housekeeping protocols for generic diesel equally important prior to blending </li></ul>
Fuel System <ul><li>Material compatibility is key for higher blends </li></ul><ul><li>Repair Fuel leaks to prevent impact to other systems! </li></ul><ul><li>From the fuel sending unit in tank to injectors </li></ul><ul><li>-primary & secondary fuel filters </li></ul><ul><li>-Fuel lines (sending & return) </li></ul><ul><li>-High pressure or </li></ul><ul><li>low pressure injectors </li></ul><ul><li>- o-rings </li></ul><ul><li>-transfer & injection pumps </li></ul>
Lubrication System <ul><li>Change oil as recommended by Engine manufacturer </li></ul><ul><li>Use OEM recommended engine oil </li></ul><ul><li>API, CI rating </li></ul><ul><li>Regular oil analysis maintenance program </li></ul><ul><li>Inspect dipstick for biodiesel smell </li></ul>
Lube Oil Contamination <ul><li>Current ongoing research, SAE CI Engine Performance with Alternative Fuels, 2008 </li></ul><ul><li>A concern of engine manufacturers. </li></ul><ul><li>Same mechanism for the oil dilution for heavier fractions of diesel fuel as for biodiesel. </li></ul><ul><li>Due to high boiling point of biodiesel, the fuel is slower to vaporize after injection into the cylinder. </li></ul><ul><li>Remaining compounds will be deposited on the cylinder wall where they can be pulled into the crankcase by the normal scraping action of the piston's oil control rings. </li></ul><ul><li>Light Duty issue, 2009+ </li></ul>
Air Filtration <ul><li>In a diesel engine, the amount of air remains constant while fuel amount is varied for speed and power control </li></ul><ul><li>Lean mixture at idle (80:1) </li></ul><ul><li>Rich mixture under load (20:1) </li></ul><ul><li>Mass Air Flow (MAF) sensor </li></ul><ul><li>VW TDI EGR/ Intake design </li></ul><ul><li>Diesels thrive on air, lots of it, any air restriction will cause performance problems </li></ul>
Starting & Charging System <ul><li>Properly charged battery </li></ul><ul><li>Operating Starter or Alternator </li></ul><ul><li>Fouled glow plugs can cause hard starting </li></ul><ul><li>Glow plugs factory recalls </li></ul><ul><li>Dual Battery system </li></ul>
Vacuum System <ul><li>Diesel maintenance issue </li></ul><ul><li>Check your vacuum lines- </li></ul><ul><li>Leaky & Inoperative vacuum system can affect: </li></ul><ul><li>Brakes, Fuel shutoff, & transmissions </li></ul>
Cooling System <ul><li>Cooling system helps your engine warm up & cool down </li></ul><ul><li>Operating at optimum temperature helps </li></ul><ul><li>fuel economy & engine life </li></ul><ul><li>Cooling system hoses are not always biodiesel compatible, repair fuel leaks immediately to prevent damage to other systems </li></ul>
Are you Smoking? <ul><li>Black smoke: injectors, air inlet restriction, engine timing, internal engine timing, injection pump failure </li></ul><ul><li>Blue Smoke: insufficient fuel, contaminated fuel, </li></ul><ul><li>High or low oil consumption, air in the fuel </li></ul><ul><li>White smoke: bad glow plugs, plugged return fuel line, insufficient fuel supply, low compression, air in fuel, injector or pump problem, engine timing </li></ul><ul><li>White smoke can be normal in cold weather before engine warms </li></ul>
Biodiesel Performance: Some Examples of Lab Durability Studies
1000 Hour Durability B20 <ul><ul><li>The 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. </li></ul></ul>hr 0 25 50 125 1000 Accelerated, high-load durability cycle Lube oil samples analyzed Engine emissions tested Engine lube oil checked Engine emissions tested Full load engine performance verified
Test Engine <ul><li>Cummins prototype 2007 ISL </li></ul><ul><li>Six cylinder 8.9 liter </li></ul><ul><li>Rated power of 330 BHP </li></ul><ul><li>Peak torque of 1150 ft•lb at 1300 rpm </li></ul><ul><li>Diesel Oxidation Catalyst (DOC) </li></ul><ul><li>Diesel Particulate Filter (DPF) </li></ul><ul><li>Post injection (in-cylinder) for active regeneration </li></ul><ul><li>Variable geometry turbocharger </li></ul><ul><li>Exhaust gas recirculation (EGR) with cooler </li></ul><ul><li>Cummins fuel injection system </li></ul>
Test Cycles <ul><li>Durability Testing </li></ul><ul><ul><li>Accelerated </li></ul></ul><ul><ul><li>High-load </li></ul></ul><ul><ul><li>Transient cycle </li></ul></ul><ul><ul><li>Varying load and speed </li></ul></ul><ul><ul><li>Cycle repeated for 1000 hr </li></ul></ul><ul><li>Emissions Testing </li></ul><ul><ul><li>Federal Test Procedure (FTP) </li></ul></ul><ul><ul><ul><li>One cold start transient FTP test </li></ul></ul></ul><ul><ul><ul><li>Three hot start transient FTP test </li></ul></ul></ul><ul><ul><ul><li>One SET Ramped Modal Cycle </li></ul></ul></ul>>70% of durability cycle at full load High Idle Low Idle Peak Torque Peak Power
Durability & Emission Results <ul><li>Approximately 17,000 gallons of B20 biodiesel fuel was used during the durability test. </li></ul><ul><li>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. </li></ul><ul><li>Engine performance was essentially the same when tested at 125 & 1000 hr of accumulated durability operation. </li></ul><ul><li>Emission results indicate that THC, CO, and PM levels were not significantly different between the B20 and ULSD. </li></ul><ul><ul><li>The emission-grade B20 test resulted in ≈6% higher NOx (within expected range) </li></ul></ul><ul><li>Fuel consumption was observed to be ≈3% higher than the 2007 certified ULSD test (within expected range). </li></ul>
Overhead Components 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
Power Transfer Components During teardown, the crankshaft was found to be in very good condition, and results were comparable to #2D diesel fuel test. Component Comments Cranckshaft Gear Meets rebuild spec Cam Gear Meets rebuild spec Cam Bushing Meets rebuild spec Fuel Pump Gear Meets rebuild spec Cranckshaft Meets rebuild spec Lower & Upper Bearings Normal wear Connecting Rod Meets rebuild spec Connecting Rod Bushing Meets rebuild spec
Power Cylinder Components Crosshatch visible in all six cylinders. Results comparable to #2D diesel fuel test. Ring Grooves Anti-Thrust Side Cylinder 1 Top Piston Piston Bowl Front Cylinder 1 Minor staining 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.
Cooling and Lube Components There were no failures found on the cooling and lube components. The wear and deposits found on the parts were normal and consistent with findings found on parts that ran with #2 diesel fuel in similar tests. Bottom (Oil) Piston Rings Cylinder 1 Top Cylinder 6 Bottom Component Comments Oil pump No issues Oil cooler head No issues Oil cooler cover No issues Oil pressure regulator/bypass No issues Piston cooling nozzles No problems due to B20. Oil Pan Normal Oil suction tube Gasket showed good imprint of seal Turbo coolant/oil lines Normal
Air Handling Components Carbon deposit layer was generated on the passage and inside parts of the EGR valve , but thickness was very thin and condition was dry which is normal for this durability test. Component Comments Exhaust Manifold No issues. EGR Cooler No cracks, light coating of soot on inlet and outlet tubes. No soot in inlet diffuser. Findings good overall. EGR Valve Looked good. Normal soot accumulation. EGR gaskets, hoses, tubes, shield, mounting plate, crossover No issues found due to running with B20.
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 Components Rail 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.
Summary <ul><ul><li>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. </li></ul></ul><ul><ul><li>During the durability testing, no biodiesel related failures occurred. </li></ul></ul><ul><ul><li>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. </li></ul></ul><ul><ul><li>A thorough engine teardown evaluation of the overhead, power transfer, cylinder, cooling, lube, air handling, gaskets, aftertreatment, and fuel system parts was performed. </li></ul></ul><ul><ul><li>There were no failures found on the engine components that were directly attributable to running biodiesel B20. </li></ul></ul><ul><ul><li>The wear and deposits found were normal and consistent with findings from parts that ran with #2 diesel fuel in similar tests. </li></ul></ul>
Fuel technology Combustion technology Aftertreatment technology Fuel system technology Better understanding of combustion Alternate Fuels (Biodiesel) Low sulfur De-NOx DOC PM trap Rate control High pressure Multi-injection EGR technology Others Control technology Technology Pathway
Sources for Filter Clogging: Petrodiesel and Biodiesel
Exposure to Air <ul><li>Enters through vent pipes and contains large amounts of moisture. </li></ul><ul><li>Generally displaces the fuel as tank is emptied. </li></ul><ul><li>It is not practical to keep air from entering the tank. </li></ul><ul><li>Will increase the oxidation of fuel. </li></ul><ul><li>Do not store fuels for long periods of time in partially empty tanks without stabilizers. </li></ul><ul><li>Consider desiccant dryers. </li></ul>
Microbial Growth <ul><li>Microbes are bacteria or fungus that live and propagate in fuel at the fuel/water interface. </li></ul><ul><li>Water needed to live—no water, no bugs. </li></ul><ul><li>Hydrocarbons in petrodiesel or biodiesel provide the food and the water provides the oxygen. </li></ul><ul><li>This environment is needed for living, growth, and reproduction. </li></ul><ul><li>The filters with microbial contamination often had an odor different from the normal fuel smell. </li></ul>
Water Contamination <ul><li>ULSD reaches water saturation at approximately 200-300 ppm. More settles to the bottom. </li></ul><ul><li>NREL B20 survey data: same water saturation level as petrodiesel. More settle to the bottom </li></ul><ul><li>B100 can hold more water, up to 1200 ppm </li></ul><ul><ul><li>Still very small—0.12%, on the same order as gasoline can hold water. Un-dissolved water settles to the bottom like it does in petrodiesel tanks. </li></ul></ul><ul><ul><li>While higher than petrodiesel, biodiesel is not water loving (i.e. hygroscopic) like ethanol is. Most people do not understand this fact. </li></ul></ul>
Icing of the filter <ul><li>When there is excess free water in fuel, it can form ice on the filter and cause filter plugging in cold temps. A filter which has been plugged but is clean and new at room temperature indicates that icing is the likely cause. </li></ul><ul><li>Since the temperatures of engines are warm, any moisture picked up within the engine can be brought back to the fuel lines. This moisture can freeze overnight in low ambient temperatures. </li></ul>Free water
Sediment/Rust build-up <ul><li>Some of the filters had solid sediment within the folds and solid particles in the filter casing. </li></ul><ul><li>Sediment present in the fuel or rust particles from within the engine can collect over time and plug the filter even when there are not necessarily problems with the fuel. </li></ul>
Paraffin Wax <ul><li>High level of paraffin material could be from the way ULSD is processed. </li></ul><ul><li>When the temperature of the fuel is at or below its cloud point, paraffin material will precipitate out and collect on the bottom of the tank. </li></ul><ul><li>When warmed to room temperature the paraffin wax will turn back into liquid. </li></ul><ul><li>Paraffin build-up does not come from biodiesel fuel. </li></ul>
Oxidation <ul><li>Filters with a black and shiny surface but no microbial growth odor or gel or sediment indicate they may be plugged by oxidation build-up. </li></ul><ul><li>Because many newer engines run at higher temperatures, there may be a black “asphaltene” petrodiesel type material collecting on the filter. </li></ul><ul><li>This phenomenon has been seen all around the country, often in newer engines. </li></ul>
Oxidation <ul><li>Petrodiesel does not have an oxidation specification, while B100 and B6 to B20 specs already do. </li></ul><ul><li>Biodiesel can also oxidize, but oxidized biodiesel manifests itself in acid numbers which are out of spec </li></ul><ul><li>The acid number for biodiesel will go out of spec before filter clogging occurs </li></ul>
Monoglyceride Build-up <ul><li>The next filter tested positive for high concentrations of saturated monoglyceride material—an out of spec or ‘imposter’ biodiesel. </li></ul><ul><li>Monoglyceride is one substance that can precipitate out of fuel if not within spec </li></ul><ul><li>Monoglycerides do not turn back into a liquid at room temperature </li></ul><ul><li>Can be distinguished from diesel by its brownish, butterscotch pudding type of appearance </li></ul>
Troubleshooting Checklist <ul><li>Microbial Growth – Exposure to air and water </li></ul><ul><li>Icing of Filter – Excess water in tank </li></ul><ul><li>Oxidation – Hot fuel return to fuel tank </li></ul><ul><li>Monoglyceride Build Up – Off specification </li></ul><ul><li>Paraffin Wax – Temperature at or below cloud point </li></ul>
Steps to Maintaining Fuel <ul><li>Store Fuel in Clean, Dry Dark Environment </li></ul><ul><li>Keep Tank Topped off to eliminate head space </li></ul><ul><li>Monitor hoses, fill/vapor caps, gaskets for leaks </li></ul><ul><li>Storage in on-site tanks should be limited to less than 6 months. </li></ul><ul><li>Once a year send your fuel to lab to be tested for microbial contamination </li></ul>
Biodiesel Use & Handling <ul><li>Refer to the Biodiesel Use & Handling Guidelines available on the Biodiesel Training Toolkit and at: http://www.nrel.gov/vehiclesandfuels/pdfs/43672.pdf </li></ul>
Using Biodiesel: <ul><li>Biodiesel Use and Handling Guidelines: </li></ul><ul><li>Ensure the biodiesel meets the ASTM specification for pure biodiesel (ASTM D 6751) before blending with petro diesel. </li></ul><ul><li>Purchase biodiesel and biodiesel blends from companies that have been registered under the BQ-9000 fuel quality program when possible. </li></ul><ul><li>Ensure your biodiesel blend supplier provides a homogenous product. </li></ul><ul><li>Avoid long term storage of B20 and higher blends to prevent degradation. Biodiesel should be used within six months . </li></ul><ul><li>Prior to transitioning to B20, it is recommended that tanks be cleaned and free from sediment and water. Check for water and drain regularly if needed. Monitor for microbial growth and treat with biocides as recommended by the biocide manufacturer. </li></ul>
Using Biodiesel: <ul><li>Biodiesel and biodiesel blends have excellent cleaning properties. Fuel filters on the vehicles and in the delivery system may need to be changed more frequently upon initial B20 use; after that, system runs cleaner with no issues. </li></ul><ul><li>Be aware of the biodiesel blend’s cold weather properties and take appropriate precautions. When operating in winter climates, use winter blended diesel fuel . Make sure the biodiesel blend cloud point is adequate for the geographical region and time of year the fuel will be used. </li></ul><ul><li>Perform regularly scheduled maintenance as dictated by the engine operation and maintenance manual. </li></ul>
Biodiesel and Aftertreatment Systems <ul><li>Biodiesel is compatible with Diesel Particulate Filters, and has some distinct advantages: </li></ul><ul><ul><li>Lowers regeneration temperatures </li></ul></ul><ul><ul><li>Less engine out particulate matter </li></ul></ul><ul><ul><li>May provide increased performance and decreased maintenance vs. ULSD alone </li></ul></ul><ul><ul><li>May provide increased fuel economy </li></ul></ul><ul><li>Regeneration mode is important </li></ul><ul><ul><li>Late in-cylinder injection may cause increased fuel dilution of engine oil and limit the level of biodiesel that can be used (i.e. B20 or B5) </li></ul></ul><ul><ul><li>Most US heavy duty applications use exhaust stream fuel injection which is compatible with B20, perhaps higher blends </li></ul></ul><ul><ul><li>Some light duty OEMs recommend max B5 at present </li></ul></ul>
B20 vs. Diesel: In the shop <ul><li>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 </li></ul><ul><li>Except: </li></ul><ul><ul><li>Expect to see fewer lubricity related issues </li></ul></ul><ul><ul><li>Expect to see fewer problems with after-treatment </li></ul></ul><ul><ul><li>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 </li></ul></ul><ul><ul><li>Less black smoke from exhaust! </li></ul></ul>
Biodiesel Resources <ul><li>www.biodiesel.org </li></ul><ul><ul><li>Biodiesel Training Toolkit </li></ul></ul><ul><ul><li>News Releases & Information Resources </li></ul></ul><ul><ul><li>Technical Library, Spec Sheets & Videos </li></ul></ul><ul><ul><li>OEM Warranty Positions on Biodiesel </li></ul></ul><ul><ul><li>U.S. Diesel Vehicle List </li></ul></ul><ul><li>www.BQ-9000.org </li></ul><ul><ul><li>Listing of BQ-9000 Certified Companies </li></ul></ul><ul><li>www.biotrucker.com </li></ul><ul><ul><li>Listing of BioTrucker retail sites </li></ul></ul><ul><li>www.biodieselautomotive.org </li></ul><ul><ul><li>Dedicated to information exchange for biodiesel & diesel technicians </li></ul></ul>
Thank You! Questions…? <ul><li>Rachel Burton </li></ul><ul><li>OEM Diesel Technician Training Program </li></ul><ul><li>wrenchwench @blast.com </li></ul><ul><li>Tel: 919-444-3495 </li></ul><ul><li>Call NBB at 1-800-841-5849 </li></ul><ul><li>Visit www.biodiesel.org </li></ul>