2. What is a fuel?
A fuel is any compound which has stored energy, it releases
useful heat when it’s burned. Burning fuel is exothermic
Examples of Fuel
Wood, coal, diesel, petrol, ECT..
3. BEST FUEL
FACTORS TO CONSIDER IN WHICH IS THE BEST.
• Which fuel is most environmentally friendly?
Hydrogen fuel is emission free and way cleaner than gas or diesel.
• How convenient are the fuels to use?
Though hydrogen is clean, our vehicles use gasoline and diesel or petrol for it’s wide
availability, thus convenient.
THUS THERE IS NO EASY ANSWER 😞
OTHER FACTORS TO THINK OF
What products are produced when they burn?
Where and how they are produced?
What are the hazards of using the fuel?
How much heat do they release? ( next slide for table)
4. Fuel Heat released when burning (KJ/g)
Ethanol 29.8
Hydrogen 143.0
Diesel 45.0
HOW MUCH HEAT?
The table shows that 1 g of hydrogen releases more heat on burning that the other fuels in the table.
Ethanol releases the least heat.
5. What are the products of combustion
• Combustion is the process of burning something
the products of combustion are the substances made when a fuel burns.
• Hydrogen has only one combustion product water
hydrogen + oxygen → water
• Ethanol is a compound of hydrogen, carbon, and oxygen. It produces
carbon dioxide and water when burned.
ethanol + oxygen → carbon dioxide and water
• Diesel is a mixture of compounds. Most of its compounds are mad up of
carbon and hydrogen only. when diesel burns, the main products are
carbon dioxide and water. Burning diesel also makes small amounts of
compounds that are solid at 20°C. Some of these products may increase the
risk of getting cancer, or heart disease
6. How are fuels produced
• Diesel is separated from crude oil. Crude oil was
formed over million of years from dead sea animals.
crude oil is an unrenewable resource. Most hydrogen
is made from methane. Methane is formed from
animal waste, and on rubbish dumps. Methane from
these sources are renewable.
• Most ethanol fuel is made from plants, such as sugar
cane. That means ethanol is renewable. However the
plants are grown on land that can also be used to grow
food.
the top 4 countries and regions producing ethanol in 2009
are:
• USA
• Brazil
• European Union
• China
Sugar cane
7. Convenience and safety
• Diesel and ethanol are liquid at 20 C. They are convenient to
transport and store. Hydrogen is a gas at 20 C, making it more
difficult to transport and store. Mixtures of hydrogen and air are
explosive , so hydrogen must be stored away from flames and
sparks.
8. Which Fuel is the best?
• There is no right answer to this question, it is subjective broski.
Different people, different opinion, depends which factor is the most
important to them yk.
9. QUESTION TIME :>
• What is a fuel?? (slide two
• Examples of fuels. (slide two)
• What does hydrogen make when burned? (slide five)
• Why do we use gasoline instead of hydrogen gas when it’s dirtier?
(slide 3)
• How is diesel made? ( slide 6)
