BIODIESEL: Understanding It's Potential and Limitations
Posted by Labels: Biodiesel, bioediesel production, biofuel productionJim Glancey
Departments of Bioresources Engineering
and Mechanical Engineering
University of Delaware
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 |
- 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
- 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.
0 comments:
Posting Komentar