Upload
vunga
View
219
Download
3
Embed Size (px)
Citation preview
1
Engine Safety and Engine Safety and Alternative Fuels Use Alternative Fuels Use
Matthew Veal, PhD NC State University
Biological and Agricultural Engineering
Engines Use Agenda Engines Use Agenda
• Engine Safety • Fuel Economy • Fuel Storage • Environmental Issues • Final Thoughts
Biofuels Biofuels Blending Blending
• Biofuels are often blended with their petroleumbased counterpart to improve performance.
• Ethanol: Loss of Energy • Biodiesel: Cold Weather
2
Biofuels Biofuels Blending Blending
• Biofuels are generally classified by the percentage of biofuel present in the blend
• BXX for biodiesel • EXX for ethanol
• E85 = 85% Ethanol 15% Gasoline
• B20 = 20% Biodiesel 80% No. 2 Diesel
Engine Safety Engine Safety
• 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
Engine Safety Engine Safety
• 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
3
Engine Safety Engine Safety • 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 • Fueltoair ratio is modified these vehicles.
Engine Safety Engine Safety • 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
Engine Safety Engine Safety
Flex fuel vehicles, like this Chev- rolet Avalanche, can be powered by either gasoline or E85.
4
Engine Safety Engine Safety • For older vehicles, there are “thirdparty” 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
Engine Safety Engine Safety • 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
Engine Safety Engine Safety • 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 lowsulfur diesel fuel
5
Engine Safety Engine Safety • 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 break up any petroleum build up in the fuel system – The service life of a fuel filter may be reduced
Engine Safety Engine Safety • 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 Safety Engine Safety • 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
6
Engine Safety Engine Safety
• 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 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 Power and Fuel Economy
Diesel > Biodiesel > Gasoline > Ethanol
7
Power and Fuel Economy 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 Power and Fuel Economy
• E10 fuel will drop the gas mileage by 12%
• E85 fuel will drop fuel economy by 2030% depending on the vehicle
• A gallon of E85 contains approximately 28% less energy than a gallon of regular gasoline.
Power and Fuel Economy Power and Fuel Economy
A reduction in fuel economy when fueling a vehicle with E85 is typical.
8
Are Are Biofuels Biofuels Cheaper? 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 Are Biofuels Biofuels Cheaper? 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 à lower energy content • $3.00/gal gasoline = $2.16/gal E85
Fuel Storage Fuel Storage • Ethanol is hydrophilic (“waterloving”)
– 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)
9
Fuel Storage Fuel Storage • Fires involving ethanol blended fuels are very dangerous – Mix readily with water – Degrade effectiveness of common firefighting foams
• Ethanol is corrosive
Fuel Storage Fuel Storage
• Storage is essentially the same as petroleum diesel
• Algae growth can occur especially if water is present in the fuel – Use AntiMicrobial Agent
• May require use of additive to improve oxidation stability
Fuel Storage 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
10
Environmental Issues Environmental Issues • Pure ethanol is nontoxic, 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 tbutyl ether (MTBE) as an oxygenate in reformulated gasoline blends
Environmental Issues 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 Environmental Issues • Pure biodiesel is nontoxic 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
11
Environmental Issues 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 Summary • Lower blends of alternative fuels pose little threat to engine safety for newer vehicles and are very similar their to petroleumbased counterparts
• Considerations must be taken when burning higher blends
• Engine Modification • Vehicle Selection
• Economics
Summary Summary • Lower blends of alternative fuels pose little threat to engine safety for newer vehicles and are very similar their to petroleumbased counterparts
• Considerations must be taken when burning higher blends
• Engine Modification • Vehicle Selection
• Economics
12
Questions? Questions?