Engine Safety and Alternative Fuels Use

Transcription

1 and Alternative Fuels Use Matthew Veal, PhD NC State University Biological and Agricultural Engineering Engines Use Agenda Fuel Economy Fuel Storage Environmental Issues Final Thoughts Biofuels Blending Biofuels are often blended with their petroleum based counterpart to improve performance. Ethanol: Loss of Energy Biodiesel: Cold Weather 1

2 Biofuels Blending Biofuels are generally classified by the percentage of biofuel present in the blend BXX for biodiesel EXX for ethanol E85 = B20 = 85% Ethanol 15% Gasoline 20% Biodiesel 80% No. 2 Diesel Generally, all engines are capable of burning some level of blended biofuel with no modification Depending on the fuel type, the type and extent of the modification will change E10 will not harm an unmodified gasoline engine E10 is actually a very popular oxygenated fuel blend Reduces greenhouse gas emissions Sold in many urban areas E10 is not considered an alternative fuel 2

3 As the amount of ethanol increases precautions need to be taken. Engine modifications are needed to use E85 blends Ethanol is corrosive Destroys the rubber hoses Eats away gaskets Ethanol increases octane rating of fuel Fuel to air ratio is modified these vehicles. Many automotive manufacturers are currently offering flex fuel or dual fuel vehicles. These vehicles provide the ability to burn either unleaded gasoline or E85 in the engine These vehicles sense the amount of ethanol present in the fuel system and adjust engine parameters accordingly Consumers are usually not charged for the flex fuel option Flex fuel vehicles, like this Chevrolet Avalanche, can be powered by either gasoline or E85. 3

4 For older vehicles, there are third party conversion kits available The EPA has yet to certify any of these kits EPA certification is necessary to insure the modification will not negatively impact the vehicle s emissions Installing an unapproved conversion kit is violation of federal law and subject to penalty Adding ethanol increases the octane rating Higher octane fuels will combust more efficiently Burning ethanol blends in older engines will loosen harmful deposits in the engine and fuel system This may require replacement of the vehicle s fuel filters Most diesel engine manufacturers are comfortable recommending burning B5 and lower blends in their engines. The lubricating properties of biodiesel are very good The inclusion of biodiesel into fuel blends is being driven in part by the need to add lubricity to low sulfur diesel fuel 4

5 Biodiesel will dissolve rubber fuel lines and fuel pump gaskets in older engines. These rubber components should be replaced Biodiesel acts like a solvent and breakup any petroleum build up in the fuel system The service life of a fuel filter may be reduced The engine warranty is often a concern Warranties cover engine failures that result from materials and workmanship issues Fuel is not a concern of the engine manufacturer Any engine failure related to a contaminated or poor quality fuelwould not be covered by the warranty Engine manufacturers have limited the recommended amount of biodiesel allowed in motor fuel out of concern for the quality of the fuel As fuels standards are developed and commercialized biodiesel production increases, engine manufacturers are being more comfortable with higher biodiesel blends 5

6 Biodiesel gels at a higher temperature Affects cold flow characteristics May require additives No. 1 Diesel Kerosene Underground storage may be required Power and Fuel Economy Fuel Economy and Power are determined by the energy content of the fuel. Energy content is measured in British Thermal Units (BTU s) or kilocalories (kcal) A BTU is the amount of energy needed to heat 1 pound of water 1 degree Fahrenheit at sea level. Power and Fuel Economy Diesel > Biodiesel > Gasoline > Ethanol 6

7 Power and Fuel Economy B2 fuel causes a drop in gas mileage that will probably not be noticeable B20 fuel blend will lead to a 2% drop in fuel economy B100 fuel will drop fuel economy by 10%. Power and Fuel Economy E10 fuel will drop the gas mileage by 1 2% E85 fuel will drop fuel economy by 20 30% depending on the vehicle A gallon of E85 contains approximately 28% less energy than a gallon of regular gasoline. Power and Fuel Economy A reduction in fuel economy when fueling a vehicle with E85 is typical. 7

8 Are Biofuels Cheaper? It really depends on market prices of petroleum products versus biofuels prices. The blends also determine price Lower blends (E10 or B5) are prices slightly less than or equal to petroleum products Are Biofuels Cheaper? Higher blends are more expensive B100 has a high production cost and may cost as much as 25% more than No. 2 diesel fuel E85 cost more because you have to buy more lower energy content $3.00/gal gasoline = $2.16/gal E85 Fuel Storage Ethanol is hydrophilic ( water loving ) Pipeline transportation is not valid E85 requires special equipment and infrastructure for storage, transportation, and distribution At low temperatures ethanol is more flammable than gasoline, (At high temperatures the opposite is true) 8

9 Fuel Storage Fires involving ethanol blended fuels are very dangerous Mix readily with water Degrade effectiveness of common fire fighting foams Ethanol is corrosive Fuel Storage Storage is essentially the same as petroleum diesel Algae growth can occur especially if water is present in the fuel Use Anti Microbial Agent May require use of additive to improve oxidation stability Fuel Storage Biodiesel Flash Point > 270 o F Petroleum Diesel F.P. = 125 o F Methanol Flash Point = 55 o F Be aware of ignition sources Biodiesel burns readily once it is ignited 9

10 Environmental Issues Pure ethanol is non toxic, water soluble, and biodegradable Biodegrades if spilled in surface water, ground water, or soil as long as oxygen is present Ethanol is currently being used to replace methyl t butyl ether (MTBE) as an oxygenate in reformulated gasoline blends Environmental Issues Ethanol also has the potential to reduce greenhouse gas emissions from automobiles by as much as 30% versus gasoline Carbon monoxide (CO) is the primary engine emission affected There is evidence that ethanol may increase volatile organic compound (VOC) emissions from automobiles Environmental Issues Pure biodiesel is non toxic and biodegradable The U.S. Department of Energy has concluded that biodiesel poses less of a threat to the environment than table salt and can biodegrade faster than sugar Biodiesel is often used as a solvent to clean up oil spills 10

11 Environmental Issues Biodiesel has also proven to burn cleaner than petroleum diesel fuel Reduces acid rain and smog causing particles Reduces harmful emissions of carbon monoxide (CO) Decreases the amount of particulates (soot) exiting a vehicle s tailpipe Eliminates Sulfur oxide emissions (SOx) The major negative about biodiesel is some studies indicate that nitrous oxide (NOx) emissions do increase. NOx is considered a greenhouse gas and major air pollutant. Summary Lower blends of alternative fuels pose little threat to engine safety for newer vehicles and are very similar their to petroleum based counterparts Considerations must be taken when burning higher blends Engine Modification Vehicle Selection Economics Summary Lower blends of alternative fuels pose little threat to engine safety for newer vehicles and are very similar their to petroleum based counterparts Considerations must be taken when burning higher blends Engine Modification Vehicle Selection Economics 11

12 Questions? 12