Biodiesel Technical Training Course BIO 2B: Biodiesel Vehicle Maintenance Presented by the National Biodiesel Board
Learning Objec-ves • Provide access to industry experts for more detailed ques-ons and answers about biodiesel • Introduce the Na-onal Biodiesel Board’s Diesel Technician Training program and the program resources to the audience • Provide technical instruc-on on biodiesel’s impact towards engine and vehicle maintenance & troubleshoo-ng • Provide instruc-on on diesel, biodiesel fuel and fuel ﬁltra-on 2
Learning Outcomes • Be able to discern issues between normal diesel problems and poor quality biodiesel imposters or out-‐of-‐spec biodiesel when they hit the shop • Be able to properly diagnose and make recommenda-ons regarding biodiesel use and vehicle maintenance • Be able to describe how fuel proper-es aﬀect fuel quality and fuel ﬁltra-on 3
Biodiesel Delivers Important Diesel Proper-es • Auto-‐igni-on = Cetane Number over 50 • BTU Content = Similar to #1, less than #2 • Viscosity = Values in diesel fuel range • Cloud Point = Current biodiesel higher than #2 • Lubricity = Naturally high in lubricity • Sulfur = Naturally less than 15 ppm • Cleanliness = ASTM specs same as petrodiesel • Stability = Spec set for 6 month min. shelf life • Emissions signiﬁcantly less for PM, HC, CO
Engine to Fuel Biodiesel only contacts the fuel system so use should not aﬀect bearings, turbo, oil/water pumps, and other wear-‐related parts. Ultra-low Sulfur Diesel • Equipment beneﬁts 800 – Superior lubricity HFRR WSD (micron) 700 600 500 – B2 has up to 66% 400 300 more lubricity than #2 200 100 Diesel 0 0.0 1.0 2.0 3.0 4.0 5.0 • No overdosing concerns Biodiesel Blend (%)
Fuel System • Material compa-bility is key for blends above B20 • Repair Fuel leaks to prevent impact to other systems! From the fuel sending unit in tank to injectors primary & secondary fuel ﬁlters Fuel lines (sending & return) High pressure or low pressure injectors O-‐rings Transfer & injec-on pumps
Solvency & Stability B20 & Under • Monitor ﬁlters, less than 2% need to be changed • Mild cleaning eﬀect • Storage tanks may need to be cleaned, or keep extra ﬁlters on hand at start up • Housekeeping protocols for generic diesel equally important prior to blending • The biodiesel speciﬁca-on contains parameters for insuring adequate fuel stability for normal applica-ons • The shelf life of biodiesel blends is recommended by NBB as 6 months
Fuel Filter:Service Intervals • Ford: Special Opera-ng Condi-ons • 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
Lubrica-on System • Change oil as recommended by Engine manufacturer • Use OEM recommended engine oil • API, CI ra-ng • Regular oil analysis maintenance program • Inspect dips-ck for biodiesel smell
Lube Oil Contamina-on • Current ongoing research, SAE CI Engine Performance with Alterna-ve Fuels, 2008 • A concern of engine manufacturers. • Same mechanism for the oil dilu-on for heavier frac-ons of diesel fuel as for biodiesel. • Due to high boiling point of biodiesel, the fuel is slower to vaporize ager injec-on into the cylinder. • Remaining compounds will be deposited on the cylinder wall where they can be pulled into the crankcase by the normal scraping ac-on of the pistons oil control rings. • Light Duty issue, 2009+
Cold Weather Performance B20 has been used Cold weather can cloud and even gel anysuccessfully in climates diesel fuel, including biodiesel.below -‐20ºF Users of a B20 with #2 diesel will usually experience an increase of the cold flow properties (cold filter plugging point, cloud point, pour point) approximately 2 to 10° Fahrenheit. Similar precautions employed for petroleum diesel are needed for fueling with 20 percent blends. • blending with #1 diesel (kerosene) • using fuel heaters and parking indoors • and using a cold-flow improvement additive
Lower Emissions 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 reduc-on tool of any liquid fuel commercially available. Emission Type B20 B2 Total Unburned Hydrocarbons -‐20% -‐2.2% Carbon Monoxide -‐12% -‐1.3% ParHculate MaIer -‐12% -‐1.3% Oxides of Nitrogen (NOX) +/-‐2% +/-‐.2%
DPF: Balance Point Temp -‐ Regenera-on Rate Results • BPT is 40ºC lower for B20 • Regeneration rate increases• Soot is more easily burned off of filter with increasing biodiesel• B20: lower temperature duty cycle OK content • Even at 5%, biodiesel PM measurably oxidizes more quickly BPT ULSD 360ºC B20 320ºC B100 250ºC
Biodiesel and Agertreatment Systems Regenera-on mode is important Biodiesel is compa-ble with Diesel • Most US heavy duty Par-culate Filters, and has some applica-ons use exhaust dis-nct advantages: stream fuel injec-on which is • Lowers regenera-on compa-ble with B20, perhaps temperatures higher blends • Less engine out par-culate • Some light duty OEMs mamer recommend max B5 at present • May provide increased performance and decreased maintenance vs. ULSD alone • May provide increased fuel economy 18
Are you Smoking? • Black smoke: injectors, air inlet restric-on, engine -ming, internal engine -ming, injec-on pump failure • Blue Smoke: insuﬃcient fuel, contaminated fuel, High or low oil consump-on, air in the fuel • White smoke: bad glow plugs, plugged return fuel line, insuﬃcient fuel supply, low compression, air in fuel, injector or pump problem, engine -ming • White smoke can be normal in cold weather before engine warms
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 fewer lubricity related issues – Expect to see fewer problems with ager-‐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! 21
What does a Fuel Filter catch? Paraffin WaxOff-spec fuel Rust
Exposure to Air: Fuel Storage • Enters through vent pipes and contains large amounts of moisture. • Generally displaces the fuel as tank is emp-ed. • It is not prac-cal to keep air from entering the tank. • Will increase the oxida-on of fuel. • Do not store fuels for long periods of -me in par-ally empty tanks without stabilizers. • Consider desiccant dryers.
Microbial Growth • Microbes are bacteria or fungus that live and propagate in fuel at the fuel/water interface. • Water needed to live—no water, no bugs. • Hydrocarbons in petrodiesel or biodiesel provide the food and the water provides the oxygen. • This environment is needed for living, growth, and reproduction. • The filters with microbial contamination often had an odor different from the normal fuel smell.
Water Contamina-on • ULSD reaches water saturation at approximately 200-300 ppm. More settles to the bottom. • NREL B20 survey data: same water saturation level as petrodiesel. More settle to the bottom • B100 can hold more water, up to 1200 ppm • 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. • While higher than petrodiesel, biodiesel is not water loving (i.e. hygroscopic) like ethanol is. Most people do not understand this fact.
Water in Fuel is a Problem All non-‐dissolved water can cause problems: • Serves as growth medium for organisms that Effect of Water on Injector Life plug ﬁlters • Concentrates acids and ionic species that 300 cause corrosion and deposits Injector Life 250• Freezes at cold temperatures and reduces fuel 200 ﬂow (%) 150• Reacts with some addiHves to form 100 precipitates and deposits 50• Plugs injector nozzles at extreme condiHons 0 25 100 200 400 500 750 1000 5000 10000• Reduces fuel lubricity when in emulsiﬁed form Amount of Water in Fuel (ppm)
Fuel-‐Water Removal More Diﬃcult in Future • ULSD addiHve package lowers interfacial 120 original or tension making removal more diﬃcult clay treated 100 additized fuel• Biodiesels have lower interfacial tension time weighted efficiency, % and hold more water, again adversely 80 impacHng removal more – FWS more challenging as biodiesel 60 additized percentage in blends increase ULSD 40• Solvency of biodiesel blends makes Biodiesel coated cellulose media opHon less 20 B20 50 eﬀecHve 0 0 10 20 30 40 interfacial surface tension, dynes/cm
Sediment/Rust build-‐up • Some of the filters had solid sediment within the folds and solid particles in the filter casing. • 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.
Paraﬃn Wax • High level of paraffin material could be from the way ULSD is processed. • 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. • When warmed to room temperature the paraffin wax will turn back into liquid. • Paraffin build-up does not come from biodiesel fuel.
Fuel Stability • Chemical degrada-on occurs with contact with oxygen for long periods or at high temperatures. • Oxida-on of fuel can form insolubles and peroxides • Peroxides increase deposits and gumming on fuel pumps and injec-on systems • Filter plugging will also occur • 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. • This may be a black “asphaltene” petrodiesel type material collecting on the filter. • ASTM D975 now speciﬁes a stability parameter
Monoglyceride Build-‐up • The next filter tested positive for high concentrations of saturated monoglyceride material—an out of spec or ‘imposter’ biodiesel. • Monoglyceride is one substance that can precipitate out of fuel if not within spec • Monoglycerides do not turn back into a liquid at room temperature • Can be distinguished from diesel by its brownish, butterscotch pudding type of appearance
Troubleshoo-ng & Maintenance Checklist Microbial Growth – Exposure to Store Fuel in Clean, Dry Dark air and water Environment Icing of Filter – Excess water in Keep Tank Topped off to tank eliminate head space Oxidation – Hot fuel return to Monitor hoses, fill/vapor caps, fuel tank gaskets for leaks Monoglyceride Build Up – Off Storage in on-site tanks should specification be limited to less than 6 Paraffin Wax – Temperature at months. or below cloud point Once a year send your fuel to lab to be tested for microbial contamination
Biodiesel Resources www.biodiesel.org • Biodiesel Training Toolkit • News Releases & Informa-on Resources • Technical Library, Spec Sheets & Videos • OEM Warranty Posi-ons on Biodiesel • U.S. Diesel Vehicle List www.BQ-‐9000.org Rachel Burton NBB Diesel Technician Training Program • Lis-ng of BQ-‐9000 Cer-ﬁed Companies email@example.com Tel: 919-‐444-‐3495 www.biotrucker.com Call NBB at 1-‐800-‐841-‐5849 • Lis-ng of BioTrucker retail sites Visit www.biodiesel.org www.biodieselautomoHve.org • Dedicated to information exchange for biodiesel & diesel 34 technicians