Biodiesel 102 Select Technical Aspects of Biodiesel for Fleet Managers, Distributors, and Users Richard Nelson National Biodiesel Board Presented to the Southeast Diesel Collaborative Atlanta, Georgia June 27, 2007
Biodiesel Defined Biodiesel, n. -- a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats, designated B100, and meeting the requirements of ASTM D 6751. Official IRS and EPA definition – goes to fuel quality. This definition should be included in all state statutes, rules, and regulations.
ASTM Current Status • ASTM D 6751 is the approved standard for B100 to be used for blending in the US • If B100 meets D 6751 and petrodiesel meets D 975, the two can be blended up to 20% • Similar to how #1 and #2 diesel are managed The MOST important factor is B100 meeting D 6751 prior to blending!!!
ASTM - D6751-07a Property ASTM Method Limits Units Calcium & Magnesium, combined EN 14538 5 max ppm (ug/g) Flash Point (closed cup) D 93 93 min. Degrees C Alcohol Control (One of the following must be met) 1. Methanol Content EN14110 0.2 Max % volume 2. Flash Point D93 130 Min Degrees Water & Sediment D 2709 0.05 max. % vol. Kinematic Viscosity, 40 C D 445 1.9 - 6.0 mm2/sec. Sulfated Ash D 874 0.02 max. % mass Sulfur S 15 Grade D 5453 0.0015 max. (15) % mass (ppm) S 500 Grade D 5453 0.05 max. (500) % mass (ppm) Copper Strip Corrosion D 130 No. 3 max. Cetane D 613 47 min. Cloud Point D 2500 Report Degrees C Carbon Residue 100% sample D 4530* 0.05 max. % mass Acid Number D 664 0.50 max. mg KOH/g Free Glycerin D 6584 0.020 max. % mass Total Glycerin D 6584 0.240 max. % mass Phosphorus Content D 4951 0.001 max. % mass Distillation, T90 AET D 1160 360 max. Degrees C Sodium/Potassium, combined EN 14538 5 max ppm Oxidation Stability EN 14112 3 min hours Workmanship Free of undissolved water, sediment, & suspended matter BOLD = BQ-9000 Critical Specification Testing Once Production Process Under Control
B5 in ASTM D 975 • 6.3 Blended Fuels and Alternative Fuels -The detailed requirements for blended fuels and alternative fuels from non-petroleum sources shall be as follows:. • 6.3.1 Biodiesel for Blending-- If biodiesel is a component of any diesel fuel, the biodiesel shall meet the requirements of D 6751. • 220.127.116.11 Biodiesel Blends -- Diesel fuel oil containing up to 5 vol% biodiesel must meet the requirements for the appropriate Grade No. 1-D or No. 2-D fuel as listed in Table 1. • 18.104.22.168 Test Method EN 14078 shall be used for determination of the vol % biodiesel in a biodiesel blend. • 22.214.171.124 Diesel fuels containing more than 5 vol% biodiesel component are not included in this specification. • 126.96.36.199 Biodiesel blends with No. 4-D fuel are not covered by this specification.
The Downstream Distributor Should: • Only accept ASTM D 6751 biodiesel • Buy from a BQ 9000 Certified Producer or Marketer • Understand fuel handling characteristics of both distillate and biodiesel fuel • Become knowledgeable about biodiesel benefits and prepare to convey them to the consumer
Microbial Contamination in Biodiesel • Biodiesel already has an ultra-low sulfur content • Some people think that biodiesel is a “food source” for microorganisms • It’s more likely the lack of sulfur in biodiesel makes microbial growth easier
Microbial Contamination in ULSD • Sulfur is used often in biocides • The correlation in decreased sulfur in diesel and increased problems with microbial growth suggests problems are due to low sulfur levels • Expect future problems with ULSD as have been seen in biodiesel blends
Treatment and Prevention • Biocides - Three major groups: Fuel soluble, Water soluble, and Universally soluble - Need to be EPA registered and compatible with the lubricant • Preventing Fuel Contamination -Preventing contamination from air and water requires proper tank maintenance and cleaning
Biodiesel Fuel Stability • Fuel stabilizers generally are not needed in biodiesel blended fuel used on a frequent basis • When using biodiesel in vehicles that sit unused for 6 months or longer, a stability additive can help ensure trouble-free use • Oxidation stability specification being added into ASTM D6751 standards
Cold Weather Performance • Wax in a vehicle fuel system is a potential source of operational snafus • A fuels CFPP, cloud point and pour point require your attention • 20% blends of Biodiesel will impact cold weather operability in direct relationship to the independent base analysis of each fuel • Pour and cloud can be addressed with kerosene blending
B100 Monitor filters closely Strong cleaning effect Storage tanks may need to be cleaned, or keep extra filters on hand at start up Wipe painted surfaces immediately B20 & Under Monitor filters, less than 2% need to be changed Mild cleaning effect Housekeeping protocols for generic diesel Fuel Filters and Solvency
New Diesel Engines • Biodiesel blends may provide SIGNIFICANT benefits with 2007 PM trap equipped engines • 2% biodiesel restores the lubricity of the poorest lubricity ULSD petrodiesel • Although similar in size/distribution, B20 particles are different than petrodiesel particles • Break Even Temperature of PM Traps reduced by 30 to 50 degrees F with B20 • May increase fuel economy w/ PM traps • May lengthen PM trap life • Engine out PM reduced • Helps EGR, reduces engine oil soot levels
ULSD & Lubricity • Sulfur compounds are natural lubricants in diesel • ULSD regulations are causing major concerns with diesel engine performance • ASTM lubricity requirement effective Jan 1, 2005 for diesel fuels • ASTM D 6079 -High Frequency Reciprocating Rig (HFRR) -Wear Scar Maximum = 520 micrometers
Biodiesel Adds Significant Lubricity to ULSD • These results were obtained by ASTM 6079, HFRR lubricity test.
Impact of Kerosene Blending with Biodiesel • Kerosene blending 20% - 40% depending on your region • 20% kerosene in conjunction with competent chemistry provides most cost effective cold weather protection for generic diesel products • Adding 10% kerosene reduces fuels BTU value (power & economy) by 1,500 BTU • Biodiesel blends enhance lubricity, eliminates lubricity issues that kerosene causes • Kerosene remains to be both economically unstable as well the first distillate grade to evaporate in tight supply markets
Blending Options (Splash) • Simply stated, the biodiesel and diesel fuel are loaded into a tank separately with relatively little mixing occurring as the fuels are placed in the tank. • The tank is usually the actual delivery truck. • The delivery truck movement to the end user has been the agitation depended upon to successfully blend the fuel as well the physical drop at the end users site. • Normally successful, but on occasion difficulties in mixing can be encountered if the biodiesel is loaded into the vessel first under very cold temperatures.
Blending Options (In-Tank Blend) • Biodiesel and diesel fuel are loaded separately, or at the same time through different incoming sources, but at high speeds which sufficiently mix without the need for additional mixing, recirculation or agitation. • Similar to splash blending but not dependent on delivery activity to continue mixing procedures.
Blend Options (In-Line Blend) • Biodiesel is added to a stream of diesel fuel as it travels through a pipe or hose in such as way that the biodiesel and diesel fuel become thoroughly mixed by the turbulence encountered in the pipe. • This is similar to the way most additives are blended into diesel fuel today and is most commonly used at a pipeline terminal and rack.
Bottom Loading • B20 is frequently blended in bottom loading environments • Biodiesel loaded first, followed by diesel fuel where mixing begins • Putting B100 into a cold empty truck can cause the B100 to gel which prohibits mixing properly • Consider loading half of the diesel then biodiesel followed by the balance of the diesel. This will help prevent the biodiesel from freezing to the internal parts of the tank truck
Storing Biodiesel • It is best to store B100 as B20 or some kind of blend as soon as possible regardless of the season in small scale bulk plants • Keep retains of all your inbound loads of biodiesel and diesel fuel, (testing precaution) • Blends of biodiesel and diesel should be stored at temperatures at least 5 – 10F above cloud point of the blended fuel • Consider stabilizing fuels being stored in excess of six months • In above ground tank environments remember the rules shown above
Engine Warranties Engines are warranted against defects in materials and workmanship. Engine warranties do not cover fuel, either biodiesel or standard petroleum diesel. Many manufacturers have issued “position statements” on the use of biodiesel fuel Example from Cummins on-line “fact sheet”: “Cummins neither approves or disapproves of the use of biodiesel fuel. …The use of biodiesel fuel does not affect Cummins Material and Workmanship warranty. Failures caused by the use of biodiesel fuels or other fuel additives are NOT defects of workmanship and/or materials as supplied by Cummins Inc. and CANNOT be compensated under the Cummins’ warranty.”