Alternative fuels are fuels other than conventional fuels like gasoline and diesel. They include methanol, ethanol, natural gas, hydrogen, biodiesel, and electricity. Methanol can be produced from biomass or coal and used in gasoline engines with minor modifications. Natural gas and LPG are cleaner burning than gasoline but LPG cylinders take up space while natural gas stations are limited. Hydrogen produces no emissions but is expensive to store and distribute. Biodiesel is made from plant oils and fats, has low emissions, and can be blended with diesel.

2. Alternative fuels means :
A. Alternative fuels, known as non-conventional or advanced fuels, are any
materials or substances that can be used as fuels, other than conventional fuels.
B. Less damaging to the environment than conventional fuels.
C. Prescribed by regulation, Including, without limiting the generality of the foregoing,
ethanol, methanol, propane gas, natural gas, hydrogen or electricity when used as a sole
source of direct propulsion energy.

3. Alternative fuels include :
1- Methanol and ethanol ( Alcohol fuels )
2- Natural gas ( compressed or liquefied )
3- Liquefied petroleum gas
4- Hydrogen
5- Biodiesel
6- Electricity ( Batteries and fuels cells )

4. Methanol
 What it is? :- Methanol is an alchol fuel. The primary
alternative methanol fuel being used is M-85, which is
made up of 85 percent methanol and 15 percent
gasoline. In the future, neat methanol (M-100), may
also be used.
 How it is produced? :- Methanol is created from a synthesis
gas, which is reacted in the presence of a catalyst.
Methanol can also be produced from non-petroleum
feed-stocks such as coal and biomass.

5. Advantages
High octane and performance characteristics.
Only minor modifications are needed to allow
gasoline engines to use methanol.
There is a Significant reduction of reactive
emissions when using M-85.

6. Natural Gas - CNG
What it is? : Natural gas is a mixture of hydro
carbons mainly methane. It can be stored on a
vehicle either in a compressed gaseous state
(CNG).
How it is produced? : Natural gas is primarily
extracted from gas wells or in conjunction
with crude oil production; it can also be
produced as a “by-product” of land fill
operations.

7. Advantages:-
1. It is cheaper than petrol and diesel.
2. It is lead free fuel.
3. It is colour less and odour less.
4. There is lot of it on india.
5. It is non-toxic.
Disadvantages:-
1. The storage cylinder takes a lot of space.
2. CNG gas stations are not widely available in India.

8. Liquified Petroleum Gas-LPG
What it is? : Liquefied petroleum gas (LPG) consists of various
hydrocarbons mainly propane, propylene, butane and butylene in various mixtures. The main
constituent, in most of the cases, is propane.
How it is produced? : LPG is a by product of natural gas
processing and petroleum refining.

9. Advantages:-
1. Its cost is 60% of petrol with 90% of its mileage.
2. Has a higher octance number and more efficiency.
3. LPG has many of the storage and transportation advantages of liquids, along with the fuel
advantages of gases.
4. Saves on the maintenance costs.

10. Disadvantages:-
 A special fuel feed system is required for liquid petroleum gas.
 There are not sufficient LPG filling stations at convenient place like petrol or diesel.
 Due to heavy load due to cylinders used for storing LPG the vehicle weight is increased.
 The ignition temperature of LPG is somewhere higher than petrol.

11. Hydrogen
 What it is: Hydrogen gas.
 How it is produced: Hydrogen can be produced from a number of different sources, including
natural gas, water, methanol etc. Two methods are generally used to produce hydrogen:
(1) Electrolysis
(2) Synthesis gas production from steam reforming
or partial oxidation.

12. Advantages:-
 Hydrogen-air mixture burns nearly 10 times faster than gasoline-air mixture.
 Hydrogen has high self-ignition temperature but requires very little energy to ignite it.
 Clean exhaust, produces no carbon-dioxide.
 As a fuel it is very efficient as there are no losses associated with throttling.

13. Disadvantages:-
 There is danger of back fire and induction ignition.
 Though low in exhaust, it produces toxic NOx.
 Its difficult to handle and store, requiring high capital and running cost.

14. Biodiesel
What it is? : Biodiesel is a fuel made primarily from the oils and fats of
plants. Although, it can be used as a straight replacement to diesel, the blend of biodiesel to
diesel can be as low 20% biodiesel. 80% diesel.
How it is produced? : Biodiesel can be produced through a
transesterfication process, forming fatty esters. One of the by products of production is
glycerol, which can then be sold as an independent product.

15. Advantages:-
 Low emissions
 It is biodegradable and non-toxic
 Low cost
 High cetance number
 High lubricidity