BioFuels: Understanding their Potential and Limitations. Jim Glancey Departments of Bioresources Engineering and Mechanical Engineering

Transcription

1 BioFuels: Understanding their Potential and Limitations Jim Glancey Departments of Bioresources Engineering and Mechanical Engineering University of Delaware Newark, DE 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

2 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

3 Catalysis = potassium or sodium hydroxide Biodiesel Sources Vegetable Oil Soy Canola/Rapeseed Corn Cotton Used cooking byproducts Animal Beef tallow Pork lard Used cooking byproducts

4 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 B % Biodiesel (Neat)

5 Worldwide Fuel Charter -ASTM 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

6 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 B F pour point in B20 30 F in B100

7 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

8 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

9 Emissions from Biodiesel Blends Compared to Petroleum Diesel Emissions...

10 Cloud Point for a Biodiesel and Biodiesel Blends no additives B100 B20 Soybean-base -14 F Canola/Rapeseed-base -15 F Lard-base -3 F Eatable Tallow -2 F Fatty Acid Grease -6 F 25 to 30 F Cloud Point - Temperature at which wax crystals start to form. Cold Filter Plug Point

11 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

12 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, 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.

13 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

14 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

15 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.