Title: FUELS

Introduction

Types of Fuels used in Vehicles

Properties of different Fuels

Factors considered for selection of a vehicle based on Fuel

Conclusion

References

Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner.

Fuel?

INTRODUCTION

Petrol

Diesel

CNG

LPG

Compressed Air

As in India, diesel and petrol are main fuel types where the main difference is defined by the cost of operating. Today we will discuss about some other fuels along with the conventional type .Which is better for what? And which should I choose?

Though there are alternative fuels like bio-gas and ethanol, we are not dealing in detail as they are not used in practice due to non-availability in sufficient quantity.

Types and Properties of Fuels

Apart from these fuels we can also use Electric and Hybrid Vehicles which are eco-friendly

A typical gasoline is predominantly a mixture of paraffin's ,naphthenes and olefins

Energy content per kilogram is higher than for gasoline (higher hydrogen to carbon ratio)

The weight-density of gasoline is about 740 kg/m³ (6.175 lb/US gal)

Gasoline contains about 43.2 MJ/L energy content

The CO2 emissions from diesel are 73.38 g/MJ

Octane rating of gasoline is it’s ability to resist Auto-ignition is measured relative to a mixture of 2,2,4-trimethylpentane (an isomer of octane) and n-heptane

Gasoline or petrol is a petroleum-derived liquid mixture which is primarily used as a fuel in internal combustion engines is a fuel of the past.

Gasoline

Diesel in general is any liquid fuel used in diesel engines produced from petroleum and many other sources.

Density of diesel is about 0.832 kg/l (6.943 lb/US gal), about 12% more than ethanol free petrol (gasoline), which has a density of about 0.745 kg/l (6.217 lb/US gal)

Offers a net heating value of 43.1 MJ/kg as opposed to 43.2 MJ/kg for gasoline

Higher volumetric energy density at 35.86 MJ/l (128 700 BTU/US gal) vs. 32.18 MJ/l (115 500 BTU/US gal) for gasoline

The CO2 emissions from diesel are 73.25 g/MJ, just slightly lower than for gasoline at 73.38 g/MJ

Cetane number for diesel is a measure of the fuel’s delay of ignition time

Diesel

Compressed natural gas (CNG) is a fossil fuel substitute for gasoline (petrol), diesel, or propane/LPG.

Produced by compressing natural gas methane [CH4]), to less than 1% of the volume it occupies at standard atmospheric pressure.

It is stored and distributed in hard containers at a pressure of 200–248 usually in cylindrical or spherical shapes.

Volumetric energy density is estimated to be 42% of LNG's (because it is not liquefied), and 25% of conventional vehicles.

CNG is less likely to auto-ignite on hot surfaces, since it has a high auto-ignition temperature (540 °C) and a narrow range (5%-15%) of flammability.

CNG can be used in Otto-cycle (gasoline) and modified Diesel cycle engines except the design should be altered.

CNG

CNG fuel systems are sealed, which prevents any spill or evaporation losses

CNG does not contaminate and dilute the crankcase oil.

CNG takes up more space for each gasoline gallon equivalent (GGE) and greater amount of space for fuel storage

Liquefied petroleum gas (LPG) is a flammable mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles. The international standard is EN 589.

Specific calorific value of 46.1 MJ/kg compared with 42.5 MJ/kg for fuel-oil and 43.5 MJ/kg for premium grade petrol (gasoline)

Energy density per volume unit of 26 MJ/l is lower than either that of petrol or fuel-oil

Higher calorific value (94 MJ/m3 equivalent to 26.1kWh/m³) than natural gas (methane) (38 MJ/m3 equivalent to 10.6 kWh/m3)

Used as an aerosol propellant and a refrigerant to reduce ozone layer damage compared to CFC’s.

Liquefied Compressed Natural Gas (LCNG). LNG can be pressurized and vaporized to give LCNG.

LPG

COMPRESSED AIR

If we can use air as fuel, why think about using anything else? Air is all around us. Air never runs out. Air is nonpolluting. Best of all, air is free.

Less working temperatures up to only 100 degree Celsius

Carbon or glass fiber tanks can crack easily are used to avoid explosion during accidents where Air is stored at a pressure of 4,351 psi

Priced at $12,700-$15000 can hit 68 mph at a range of 125 miles

Takes just minutes to get refueled

Cost only around $2 to fill the car up with 340 liters of air

0.176 pounds of carbon dioxide emissions per mile compared to 0.40 of I.C engines

Already the “ Evolution car ” that is being built by Zero Pollution Motors, in Brignoles, France and the engine is some 50% more efficient than the four-stroke variety.

CityCAT developed by MDI is about to be introduced in India by TATA Motors

ELECTRIC VEHICLE

12g per km CO2 emissions compared to 250g for a conventional vehicle

$5000 - $ 8000 more expensive than an conventional vehicle

Battery consumption cost of US$ 0.1174 per 1 mile (1.6 km)

Top speed of 250 mph and can accelerate from 0 to 60 mph (97 km/h) in 3.7 seconds

On-board efficiency of around 80% compared to 15% of gasoline and 20% of Diesel engines

Vehicle efficiency is typically 24.4 kW·h/100 km

High torque over a larger range of speeds during acceleration because they are function of current, not rotational speed

An Electric car is a plug-in battery powered automobile which is propelled by electric motor(s) unlike a hybrid car, which is propelled by gasoline and uses a battery and motor to improve efficiency .

HYBRID VEHICLEA Hybrid electric vehicle (HEV) is that which uses two or more distinct power sources to move the vehicle generally an I.C engine and one or more electric motors.

The types of Hybrids are:• Parallel hybrid• Mild parallel hybrid• Power-split or series-parallel hybrid• Series hybrid• Plug-in hybrid electrical vehicle (PHEV)

HEV has an average mileage rating of 60 mpg/city and 66 mpg/highway

Top speed of 50 to 100 miles from 90 horsepower at 5,700 rpm

The rare earth element dysprosium used in motor parts and Neodymium in high-strength are rare and costly elements

Reduce air emissions of smog-forming pollutants by up to 90% and 50% of CO2

Use of lithium-ion batteries reduces the weight of the vehicle and also achieves improved fuel economy of 30% better than gasoline-powered vehicles

Shutting down the engine during traffic stops or while coasting or during periods

Improving aerodynamics

Reduces mechanical losses

Regenerative braking

Factors influencing to choose a vehicle are:

Now that we have understood about each type of vehicle , let us check out some more commercial factors affecting a customer.

Investment

Running cost

Maintenance

Comfort

Performance

Environment

Availability

Of the fuel types mentioned, we can easily state that petrol engine is the cheapest. This is because the petrol engine is the base engine and simplest one. CNG and LPG both require minor engine modifications. The diesel engine is technically more complex than the petrol engine and hence also more expensive. The Electric and Hybrid are also costly because of the design changes and might charge up to 250000 more than petrol engine.

Rank Fuel Type Expense vs. Petrol

1 Petrol 0

2 LPG 20000

3 CNG 40000

4 Diesel 100000

5 Air 150000

Investment

The running costs of different fuel types, is determined by the cost per liter/kg of the fuel, and the mileage of the same.Electric and Hybrid vehicles cost very cheap up to Rs 05 / L

Rank Fuel Type Cost

1 CNG Rs 18 / KG

2 LPG Rs 25 / KG

3 Diesel Rs 38 / L

4 Petrol Rs 50 / L

5 Air Rs 0.3 / L

Running cost

A gasoline vehicle’s expected mileage is around 15 KMPL on an average and hence the cost per KM will be Rs 3.3 (Rs 50 divided by 15) and as shown for others.

Rank Fuel Type Cost Mileage (AVG) Cost per KM

1 CNG Rs 18 / KG 21 KM/KG Rs 0.84

2 LPG Rs 25 / KG 21 KM/KG Rs 1.15

3 Diesel Rs 38 / L 17 KMPL Rs 2.3

4 Petrol Rs 50 / L 15 KMPL Rs 3.3

5 Air Rs 25 / L 28 KMPL Rs 0.9

•Maintenance is mainly of two types

• Periodic (scheduled) maintenance is replacing of parts etc as per the expected good life

• Breakdown maintenance is the replacement of damaged parts of problems that arise suddenly

•Diesel engines maintenance are costlier to petrol vehicles also are LPG/CNG engines.

•CNG/LPG engines, the cost of repairs will increase with problems arising in head assy.

•Electric/Hybrid batteries needs to be checked daily .

Rank Fuel Type

1 Petrol

2 Diesel

3/4 CNG / LPG

5 Air

Maintenance

Petrol engines are recognized for its smoother operation, quietness and good acceleration

Diesel engines on the other hand are quite noisy, have slower pickup and frequent cold starting problems

LPG and CNG, problems are reported for foul smell, cold starting problems

The Electric, Air and Hybrid probably produce lesser noise than others

Rank Fuel Type

1/2 Air

3 Petrol

4 LPG/CNG

5 Diesel

Comfort

Petrol engines have an advantage over other fuels in terms of faster pickup and power

Diesel engines accelerate slowly and are more suitable for long usages

LPG/CNG fitments suffer from a slight lack of initial pickup, but accelerate faster than their diesel type

Electric and Hybrid operate at good speeds but the Air vehicle remains at the last

Rank Fuel Type

1 Petrol

2/3 LPG/CNG

4 Diesel

5 Air

Performance

Petrol has the disadvantage of emitting carbon monoxide, which is a very poisonous gas

Diesel, though it emits dusty gas, has more environment friendly emissions than petrol

LPG/CNG are much more environmental friendly and produces a clean exhaust gas

Electric is the least polluter as Air and Hybrid follow them

Environment

Rank Fuel Type

1 Air

2/3 LPG/CNG

4 Diesel

5 Petrol

Petrol and diesel are easily available at all gas stations

LPG, CNG ,a large amount of it is produced in India and risk of price shocks is smaller

Electricity is a problem which the government should come up with a solution

Availability

Rank Fuel Type

1 Petrol

2 Diesel

3/4 LPG/CNG

5 Air

Usually in certain areas either of CNG or LPG is available. Hence, for users, the choice is generally between diesel, petrol or CNG (for North India) or diesel, petrol or LPG (for South India).

EngineType

Invest- ment

Running Cost

Mainte- nance

Comfort Perfor- mance

Environ- ment

Availability

Conclu- sion

Petrol 1 3 5 4 1 6 4 ?

Diesel 3 2 6 6 3 5 5 ?

LPG/CNG 2 1 3 5 2 4 2 ?

Electric 4 6 2 1 5 1 6 ?

Air 6 5 1 3 6 2 1 ?

Hybrid 5 4 4 2 4 3 3 ?

Conclusion

Now, I have left the conclusion column empty on purpose.

Why? Because, this depends completely on your personal preferences.

Do you want a speedy, fast car? Then petrol is the way to go.

Are you nuts about the environment? CNG , LPG or HYBRID are for you.

Do you want economy with carefree ownership? Then diesel would be most likely be better for you.

Near zero emissions go for Electric.

THANK YOU

References

http://www.howstuffworks.com/electric-car.htm

http://www.hybridcars.com/electric-car

http://www.cartradeindia.com/car-bike-news/petrol+-diesel+-cng-or-lpg-we-help-you-choose--111207.html

http://en.wikipedia.org/wiki/Liquefied_petroleum_gas

http://en.wikipedia.org/wiki/Compressed_natural_gas

JOURNAL OF ENGINES – SAE Transactions

http://www.aircarfactories.com/FAQ_AirCar.html

www.tiaxllc.com