BIODIESEL: Understanding It's 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

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

The Biodiesel Reaction

Biodiesel Sources

• Vegetable Oil
• Soy
• Canola/Rapeseed
• Corn
• Cotton
• Used cooking byproducts

• Animal
• Beef tallow
• Pork lard
• Used cooking byproducts

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)

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

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

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

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

Emissions from Biodiesel Blends Compared to Petroleum Diesel

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

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

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
• 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.
• 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

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

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.