Alternative Fuels M.Thirunavukkarasu , Assistant Professor, Department of Automobile EngineeringDr.Mahalingam College Of Engg. & Tech., Pollachi .
Why Alternative Fuels?• As the cost of conventional fuels goes up, the interest in other fuel sources increase• In some cases, alternative fuels are more environmentally friendly• Some alternative fuels are more energy efficient
Why Alternative Fuels?• Reduce toxic emissions• Eliminate support for oil based politics• Eliminate environmental impact of harvesting, transporting, and manufacturing gasoline• Fossil Fuels are not sustainable
Key Drivers of Alternative Fuels Increased Environmental Fuel Cost problemsKyoto AlternatiProtocol & ve FuelsCarbon Tax Refinery Requirements Depletion of fossil fuels
ALTERNATIVE FUELSWhat are Alternative Fuels?• A fuel that can be used in place of gasoline or diesel fuel.• Fuels that are substantially non-petroleum and yield energy security and environmental benefits
What are Alternative Fuels? Major Alternative Fuel Groups Gaseous BioFuelsHydrogen Electric fuelFuel Cells Hybrids fossils Liquefied Compresse BioDiesel Ethanol (Vegetable (Sugarcane Petroleum d Natural Oil, Jatropha) , Corn) Gas (LPG) Gas (CNG)
Alternative Fuels• Alcohol Fuels – Ethanol – Methanol• Biodiesel• Electricity• Hydrogen• LPG• Natural Gas (CNG, LNG)• Others under development (P-series, diesohol)
Ethanol• Ethanol is an alcohol-based alternative fuel produced by fermenting and distilling starch crops or cellulose that have been converted into simple sugars• Ethanol is most commonly used to increase octane and improve the emissions quality of gasoline.• Ethanol can be blended with gasoline to create E85, a blend of 85% ethanol and 15% gasoline.• Ethanol can degrade quickly in water, therefore, posing less environmental harm than oil in the case of a spill
Ethanol• Ethanol is an excellent, clean-burning fuel, potentially providing more horsepower than gasoline. In fact, ethanol has a higher octane rating (over 100) and burns cooler than gasoline• One acre of corn can produce 300 gal. of ethanol per growing season. So, in order to replace that 200 billion gal. of petroleum products, American farmers would need to dedicate 675 million acres, or 71 percent of the nations 938 million acres of farmland, to growing feedstock.
Ethanol Properties• Alcohol-based fuel produced from starch crops or cellulosic biomass (trees and grasses). Currently, corn is primary feedstock.• High octane (100+); enhances octane properties of gasoline and used as oxygenate to reduce CO emissions.• 27% - 36% less energy content than gasoline. OEM’s estimate 15% - 30% decrease in mileage.• E85 vehicles demonstrate a 25% reduction in ozone- forming emissions compared to gasoline.• As an alternative fuel, most commonly used in a blend of 85% ethanol and 15% gasoline (E85).
INDIAN SCENARIO• India is the second largest producer of sugarcane in the world with 280 MTPA• India stands fourth in the world in ethanol production about 1.3 Billion liters per annum.• The installed capacity is about 2.7 Billion liters PA in 278 distilleries.
Ethanol Uses• Mostly used in light-duty vehicles called flexible fuel vehicles (FFVs). FFVs can use 100% unleaded fuel or any mixture of E85 and unleaded fuel..
Ethanol Considerations• Decreased mileage.• High level of fuel pricing volatility until demand and supply balance.• Refueling infrastructure not in place in all areas• Ongoing debate: energy balance, land mass, food vs. fuel, and water required.
PROPERTIES OF ETHANOL• Ethanol is Colourless• Boiling temperature of ethanol is 780C• Specific gravity of ethanol is 0 .794• Viscosity of ethanol is less• Emulsifier manufacturer provide water tolerance of 3% to ethanol-diesel emulsion- this makes it possible to miscible with water in all proportions• It is an excellent solvent for fuels,oils,fats etc.,
PROPERTIES OF ETHANOL IN COMPARISON WITH DIESEL PROPERTY ETHANOL DIESELSpecific gravity 0.794 0.82-0.85Latent heat of vaporization (kJ/kg) 853.84 600Stochiometric A/F ratio 9.0 14.6Calorific Value (kcal/kg) 6400.5 10500Self ignition temperature(0C) 420 220Cetane no. 8 40-60Viscosity (cst) 2.5 - 3 4-6
• INDIAN EXPERIENCE- ETHANOL• 1979 - The Ministry of Petroleum, Chemicals and Fertilizers, constituted an Inter- Departmental Committee to examine the use of alcohol as fuel in admixture with gasoline.• 1980 - Trials were conducted on 15 passenger cars in collaboration with IIP, Dehradun. Trials were also conducted on scooters, motor- cycles and three wheelers.
Methanol• Methanol, also known as wood alcohol, can be used as an alternative fuel in flexible fuel vehicles that run on M85• It is not a commonly used fuel at this time as methanol produces a high amount of formaldehyde in emissions.• The benefits include lower emissions, higher performance, and lower risk of flammability than gasoline• Methanol can easily be made into hydrogen for hydrogen fuel cell vehicles in the future.
Methanol• Methanol is extremely corrosive, requiring special materials for delivery and storage. Methanol, in addition, has only 51 percent of the BTU content of gasoline by volume, which means its fuel economy is worse than ethanols.• Methane also can be produced by processing biomass such as grass clippings, sawdust and other cellulose sources.
Natural Gas• Natural gas is produced either from gas wells or in conjunction with crude oil production.• Because of the gaseous nature of this fuel, it must be stored onboard a vehicle in either a compressed gaseous state or in a liquefied state• A natural gas vehicle can be less expensive to operate than a comparable conventionally fueled vehicle depending on natural gas prices.• The United States has vast natural gas reserves across the country• Vehicles tend to cost $3500 to $6000 more than gasoline powered ones
Natural Gas Properties• Recovered from underground reserves.• Used in two forms: CNG (compressed natural gas) and LNG (liquefied natural gas).• CNG and LNG vehicles can demonstrate reduced ozone-forming emissions compared to gasoline. May have increased hydrocarbon emissions.• Contains 59% - 69% less energy content per gallon at 3000 - 3600 psig than gasoline.
CNG/LNG Uses• CNG used in light- and medium-duty vehicles.• LNG used in heavy-duty trucks and all natural gas fueled locomotives.• CNG stored onboard at 3000 - 3600 psig.• LNG stored at 50 psig and fuel temperature at -2200F.
CNG/LNG Considerations• CNG refueling stations are either slow-fill (several hours to fill) or fast-fill (2 - 5 minutes).• Additional safety modification for maintenance facilities required by NEC (National Electrical Code) and NFPA (National Fire Protection Association).• Higher vehicle costs because of required tank configuration.• Shorter vehicle range for CNG vehicles.• Availability of refueling stations.
Propane• Propane or liquefied petroleum gas (LPG) is a popular alternative fuel choice for vehicles because there is already an infrastructure of pipelines, processing facilities, and storage for its efficient distribution.• LPG produces fewer vehicle emissions than gasoline.• Propane is produced as a by-product of natural gas processing and crude oil refining.• Propane vehicles can produce fewer ozone-forming emissions than vehicles powered by reformulated gasoline• The cost of a gasoline-gallon equivalent of propane is generally less than that of gasoline, so driving a propane vehicle can save money.
Propane (LPG) Properties• By-product of natural gas processing and crude oil refining.• HD5, the automotive propane standard, a mixture of 90% propane and other hydrocarbons.• Contains 33% - 41% less energy content per gallon than gasoline.• LPG vehicles can demonstrate a 60% reduction in ozone-forming emissions compared to gasoline.• High octane properties (~104) allow LPG vehicles to operate with higher compression ratios; leads to higher efficiency/fuel economy.
Propane (LPG) Uses• Used in light- and medium-duty vehicles, heavy-duty trucks and buses.• Popular choice for non-road vehicles such as forklifts and agricultural and construction vehicles.• Many propane vehicles are converted gasoline vehicles. (Conversion kits include regulator/vaporizer, air/fuel mixer, oxygen-monitoring closed-loop feedback system, and special fuel tank.)
Propane (LPG) Considerations• Widespread infrastructure of pipelines, processing facilities, and storage (2,499 stations in U.S. offered LPG in 2006).• For vehicles, need to balance range vs. payload reduction caused by larger fuel tanks.• Increased vehicle costs.
Hydrogen• Hydrogen, a gas, will play an important role in developing sustainable transportation in the United States, because in the future it may be produced in virtually unlimited quantities using renewable resources.• Hydrogen and oxygen from air fed into a proton exchange membrane fuel cell produce enough electricity to power an electric automobile, without producing harmful emissions. The only byproduct of a hydrogen fuel cell is water.• Currently there are no original equipment manufacturer vehicles available for sale to the general public. Experts estimate that in approximately 10-20 years hydrogen vehicles, and the infrastructure to support them, will start to make an impact.
Hydrogen Properties• Does not occur to any significant extent on earth in its free, elemental form.• Found in chemical compositions such as water and hydrocarbons, and dry coal.• Pure hydrogen contains no carbon thus burns to form water with no CO2 or CO emissions.• One kg of hydrogen contains roughly equivalent energy to one gallon of gasoline.• Can be stored as compressed hydrogen at 5,000 – 10,000 psi or liquid hydrogen (cooled to -4230F).
Hydrogen Uses• Emerging fuel for transportation fuel cells.• Used in modified internal combustion engines.• Fuel cells use a direct electrochemical reaction to produce electricity on board the vehicle. This electricity is used to power electric motors.• Ongoing demonstration projects in select U.S. areas.
Hydrogen Considerations• Vehicles not available for commercial sale.• Infrastructure extremely limited (31 demonstration-level refueling stations in the U.S in 2006).
HYDROGEN• Easy to convert existing engine to work with H2.• Has excellent properties as a SI engine fuel.• Wide flammability limits of H2,make the engine to work without throttle.• Thus reduces pumping losses, hence causes an increase in the thermal efficiency.• High burning velocity leads to almost constant volume combustion.• High self ignition temperature, thus allows to work with high compression ratio . i.e. increase in thermal efficiency.• H2 is a clean burning fuel, steam is the only product of 35 combustion.
CHALLENGES FACED• Due to low ignition energy ,it is more prone to backfire, But this can overcome by adopting EGR or water injection in the manifold.• H2 is odourless & has an invisible flame. Hence safety problems have to be overcome if H2 is used as an alternate fuel. 36
PROPERTIES OF H2 Pro pe rty Hydro ge n Gaso line Limit s of inflammabilit y 4 to 75 1.1 to 3.3 ( % fuel in air )Stoichiom et ric laminar burning 265 37 velocit y ( cm/ sec )Auto-Ignit ion Tem perat ure ( °C ) 580 340Minim um Ignit ion energy ( m j ) 0.02 0.24 st oichiomet ric mixt ure 34.4 14.7 mass rat io ( Kg air / Kg fuel ) Lower ent halpy of combustion 119930 45000 in ( KJ / KgK ) Higher ent halpy of combustion 141860 48000 in ( KJ / KgK ) 37
HYDROGEN STORAGE• Compressed state(140 bar)• Liquid hydrogen• Metal hydride system 38
Electricity• Electricity can be used as a transportation fuel to power battery electric and fuel cell vehicles. When used to power electric vehicles, electricity is stored in an energy storage device such as a battery.• EV batteries have a limited storage capacity and their electricity must be replenished by plugging the vehicle into an electrical source.• EVs have lower "fuel" and maintenance costs than gasoline-powered vehicles.
Electricity• Vehicles that operate only on electricity require no warm- up, run almost silently and have excellent performance up to the limit of their range. Also, electric cars are cheap to "refuel." At the average price of 10 cents per kwh, it costs around 2 cents per mile.• Pure electric cars still have limited range, typically no more than 100 to 120 miles.
Electricity Properties• Recharges batteries in electric vehicles.• Electricity sources for battery recharging (electrical outlet, gasoline engine on-board vehicle, regenerative braking).• Electricity sources for power outlets (coal, natural gas, nuclear, wind, other renewables).
Electricity Uses• Two categories include EVs or plug-ins (externally charged) and HEVs or hybrid vehicles (self-charged). Both use battery storage.• Available in neighborhood electric vehicles, bicycles, light- duty vehicles, medium- and heavy-duty trucks and buses.• Hybrids use an electric motor or a combination of a gasoline engine and electric motor to drive the wheels. Hybrids use batteries to store electricity produced by regenerative braking and the onboard generator.• Range of a dedicated electric is typically 50-130 miles.
Electricity Considerations• Fuel savings (10% - 100% depending on application and vehicle).• Payback on investment.• Possible federal and state tax credits for purchase of hybrid.
What is Biodiesel?• Biodiesel is the name of a clean burning alternative fuel, produced from domestic, renewable resources. Biodiesel contains no petroleum, but it can be blended at any level with petroleum diesel to create a biodiesel blend. It can be used in compression-ignition (diesel) engines with little or no modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics. (National Biodiesel Board)
Biodiesel• Biodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant greases.• Biodiesel is safe, biodegradable, and reduces serious air pollutants such as particulates, carbon monoxide, hydrocarbons, and air toxics.• Biodiesel can also be used in its pure form but it may require certain engine modifications to avoid maintenance and performance problems and may not be suitable for wintertime use.
n 1911 Dr.Rudolph Diesel stated as: “The diesel engine can be fed with vegetable oils and would help considerably in the development of agriculture of the countries which use it.” 46
In 1912,he stated as:“The use of vegetable oilsfor engine fuels mayseem insignificant today.But such oils maybecome in course of timeas important aspetroleum and the coaltar products of thepresent time.” 47
How is Biodiesel made?• Biodiesel is made through a chemical process called transesterification whereby the glycerin is separated from the fat or vegetable oil. The process leaves behind two products -- methyl esters (the chemical name for biodiesel) and glycerin, a valuable byproduct used in soaps and other products. (National Biodiesel Board)
Bio diesel• Pure biodiesel, B100, costs about $3.50--roughly a dollar more per gallon than petrodiesel.• Need to heat storage tanks in colder climates to prevent the fuel from gelling• Like E85, biodiesel began with farm co-ops and local entrepreneurs. High fuel prices affect farmers, too, and here was an opportunity to make money from otherwise fallow farmland.
Why choose Biodiesel over SVO?• Biodiesel is legal, SVO is not• Less car maintenance required• Less operational headaches• More consistent fuel sources• Backed by your engine’s warranty
Vegetable oils• Chemically defined as mono alkyl esters of fatty acids
WHY VEGETABLE OIL?• Decreasing reserves, unstable supplies from Petroleum Industries• Vegetable oils are renewable from inexhaustible sources of energy• Easily produced in rural areas• Country like India has strong agricultural base and possible to produce massively at cheaper cost• To clean environment• Vegetable oil properties are comparable to diesel
PROPERTIES OF VEGETABLE OILS• Slightly higher density• Slightly lower (10%) calorific value on mass basis• Higher viscosity at room temperature• Slightly lower cetane number• Low volatility• Low sulphur content• High carbon residue
Why vegetable oils in diesel engine? • Have high thermal efficiency • Can burn low cetane value fuels • Very long service life • 80 % of prime movers use diesel fuel
Pongamia pinnata • This is most abundantly available in India • Common name of the oil Karanj oil • Other Names • Hindi: Karanj • Kannada: Honge • English: Indian beech • Telugu: Kanuga • Tamil: Punnai