BioFuels: Understanding their Potential and Limitations
Jim Glancey Departments of Bioresources Engineering and Mechanical Engineering
University of Delaware Newark, DE 19716
Discussion Items
The Basics of Biodiesel Production, Distribution and Blending Performance as an Engine Fuel Warranties Heating Oil Handling and Storage to Maintain Fuel Quality
1 Biodiesel – Driving Forces
Excess supply of fats and oils Potential for better emission Reduce dependence on petroleum Increase lubricity of the fuel to compensate for lower Sulfur content Safety and handling – less volatile fuel Incentive Programs
What is Biodiesel?
A compression ignited fuel made from a renewable resource Chemically
Long chain fatty acid mono alkyl esters
Exact chemical composition different for different sources of oil.
Combustion Biodiesel Air/Fuel Ratio = 13.5 Petro-Diesel Air/Fuel Ratio = 15 Its a good solvent
2 Catalysis = potassium or sodium hydroxide
Biodiesel Sources
Vegetable Oil Animal
Soy Beef tallow
Canola/Rapeseed Pork lard
Corn Used cooking by-
Cotton products
Used cooking by- products
3 Important Processing Considerations
Complete reaction = no un-reacted oil Removal of Glycerin Removal of Catalyst Removal of Alcohol Absence of free fatty acids
Insured through ASTM D6751
Classifications
Biodiesel always refers to 100% biofuel. Biodiesel Blends refers to a fuel that is composed of a mix of Biodiesel and Petroleum-Based Diesel Blend Designations
BXX – XX is the % Biodiesel
Examples: B20 – 20% Biodiesel, 80% Petro-Diesel B100 – 100% Biodiesel (Neat)
4 Worldwide Fuel Charter
-ASTM 6751 -B5 Recommendation
Blending
Biodiesel that meets ASTM 6751 is blended with Petroleum Diesel Fuel.
Some common blends: B2, B5, B20 Biodiesel is heavier than Petroleum Diesel Splash Blending (Tank Mixing)
Always add biodiesel on top of petroleum diesel
Cheap and effective for mixing
5 Rack or In-Line Blending
Simple Rack Blender Blending with Additives
Blending in Delaware/Maryland
Distributors with up to 3 years experience Buying B100 from Iowa and Ohio Blend B100 with petro-diesel. Underground Tanks for B100 are temperature controlled Sell everything from B2 to B100 Cold flow improver in bulk B100 -40 F pour point in B20 30 F in B100
6 Biodiesel Blend Quality
Unlike gas engines, diesel engines will run on poor fuel.
Currently, no good test or standard exists for blended biodiesel.
Once blended, it is difficult to determine if good quality biodiesel was used.
So . . . you need to interrogate and rely on your supplier to confirm quality.
Biodiesel Performance
Power and Efficiency Emissions Low Temperature Material Compatibility Cost
Taken at the diesel truck drag races on Rt. 13 just outside Greenwood, DE
7 Performance – Energy Value
Power and Efficiency Compared to Petroleum Diesel
B100 – 10% less energy per gallon B20 – about 2% less energy per gallon Road studies of fuel efficiency reductions
B100: 4.1 to 10.1 MPG
B20: 0.9 to 2.1 MPG
8 Emissions from Biodiesel Blends Compared to Petroleum Diesel
Emissions . . .
9 Cloud Point for a Biodiesel and Biodiesel Blends – no additives B100 25 to 30 F B20
• Soybean-base -14 F
• Canola/Rapeseed-base -15 F
• Lard-base -3 F
• Eatable Tallow -2 F
• Fatty Acid Grease -6 F
Cloud Point - Temperature at which wax crystals start to form.
Cold Filter Plug Point
10 Material Compatibility
Soft Metal Copper, brass, zinc, lead and tin parts should be replaced with aluminum or steel since these metals oxidize both diesel and Biodiesel fuels.
Seals Teflon and Viton are must use sealing devices, not Buna, Nitrile, Polyurethane. Polypropylene and Polyvinyl are not acceptable sealing devices.
Biodiesel Costs
B100 – about $3.00/gal at the pump $2.00/gal for the fuel $0.50/gal rail charge from Iowa $0.50/gal road tax B20 - $1.76/gal at the pump Rule of thumb – an extra penny per gallon for each percentage point of biodiesel
11 Warranty Issues
Cummins and Caterpillar “neither approves or disproves the use of biodiesel fuel and blends” Problems causes by the fuel will not be covered. Caterpillar B5 blend maximum for 3003 through 3034, 3054, 3056 engine models Other models - blended at any percentages are OK.
Warranty Issues . . .
John Deere Most recent policy statement regarding Biodiesel blends was February, 2002. Approved up to 5% soy-based blend in all Power Tech engines. “We do not endorse using higher percentage blends at this time” Why? Possible fuel quality issues Deere R&D is consumed with developing a new engine to meet the Tier 3 emission requirements required in 2006.
12 Warranty Issues . . .
Volkswagen
Some claims that VW voids warranties if biodiesel blends are used.
Currently, European VW engines are warranted for B20 and B100.
VW had invested in “Sunfuel” - biodiesel from biomass.
Volkswagen AG and Archer Daniels Midland Announce Biodiesel Research Agreement Announced Monday January 5
Biodiesel Blends as Heating Fuel
B2 and B5 have been used Emissions including NOx goes down Given the change in fuel chemistry, adjustment of the air/fuel ratio may be required. Soft metal fuel lines (copper) and natural rubber present problems
13 Maintaining Fuel Quality
Purchase only quality fuel and keep it clean Start with clean storage Minimize Contaminants Air Water Fuel Microbes Don’t store biodiesel for more than 6 months Regular housekeeping Problems usually occur early
Fuel Additives
Four Types for Diesel
Engine Performance
Fuel Stability
Fuel Handling
Contamination Control
14 Biodiesel Incentive Programs
Delaware Soybean Board
Paying for a soybean grower’s first purchase of Biodiesel
Planning to offer totes MD Soybean Board
Refunds half the cost up to $1000
Giving away $275 totes
Summary
Extensive research exists on biodiesel formulations and performance.
One of the biggest challenges for the industry is insuring consistent quality at a competitive price.
Important issues for end users: Know and trust your source of fuel Make sure fuel meets fuel standards When in doubt, verify warranty policy Check regularly for seal degradation with older engines
End users responsible for maintaining fuel quality.
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