Fuels and Stoichometry

Question 1

What is a fuel?

Answer 1

Is a substance with a large amount of chemical energy stored in it.
- Fuels release this energy by burning.

Question 2

What are the two types of fuels?

Answer 2

1. Fossil Fuels
2. Biofuels

Question 3

Fossil Fuels:

Answer 3

• Non-renewable Fuels
• Made from compressed dead plants/animals (fossils)

Question 4

Biofuels:

Answer 4

-Renewable
- Fuels that derive from plant materials.
- Can be mixed with other fossil fuels.
- Don’t contribute significantly to CO2 levels because the plants absorb the CO2.

Question 5

3 common biofuels:

Answer 5

-Bioethanol
-Biogas
-Biodiesel

Question 6

Bioethanol:

Answer 6

• Any product with E10 next to it contains 10% Bioethanol
• produced from fermentation of sugar (glucose) from plant materials:
  C6H12O6 –>2CH3CH2OH + 2CO2
• Reduces amount of CO2 released in atmosphere.

Question 7

Biogas:

Answer 7

This material is released during the breakdown of organic matter by anaerobic bacteria (bacteria that don’t require oxygen)
- Anaerobic bacteria: take complex carbohydrates and proteins and break them down into CO2 and methane.

Question 8

Biodiesel:

Answer 8

Is a mixture of organic compounds called esters. These are produced when vegetable oils/animal fats react with an alcohol.
- Biodegradable & non-toxic

Question 9

Biofuel vs Fossil fuels: (Type)

Answer 9

Renewable - Biofuel
Non-renewable - Fossil fuels

Question 10

Biofuel vs Fossil fuels: (Source):

Answer 10

Organic plant matter - Bio
Ancient organisms - Fossil

Question 11

Biofuel vs Fossil fuels: (Impact on health)

Answer 11

Non-toxic - Bio
Toxic ingredients and by-products - Fossil

Question 12

Biofuel vs Fossil fuels: (Energy density)

Answer 12

Low - Bio
High - Fossil

Question 13

Biofuel vs Fossil fuels: (Environmental effect)

Answer 13

Friendly - Bio
Harmful - Fossil

Question 14

Biofuel vs Fossil fuels: (CO2 Emissions)

Answer 14

High - Bio
High - Fossil

Question 15

Biofuel vs Fossil fuels: (State of industry)

Answer 15

Growing - Bio
Declining - Fossil

Question 16

Composition of fuels calc:

Answer 16

m(X) = %/100 x m

Question 17

Energy content in fuels calc:

Answer 17

n x ∆Hc (change in heat for combustion)

Question 18

Advantages of biofuels:

Answer 18

• Non toxic
• Carbon-neutral fuel source, because the biomass used to make the biofuel is always regrown.
• Allow for less dependance on imported petroleum

Question 19

Disadvantages of biofuels:

Answer 19

• Amount of energy not enough to replace fossil fuels.
• Create competition for land between crops and fuel.
• Not all biofuels are carbon neutral
• Biofuels made from grain produce same carbon emission as fossil fuels.

Question 20

Oil:

Answer 20

• Oil is a liquid substance composed of hydrocarbons that once composed living organisms.
• Source of liquid fuels such as gasoline
• Provides high energy density

Question 21

Oil - Disadvantages:

Answer 21

• Extraction methods are hazardous to natural environment
• Oil spills destructive to both animals, plants and the environment.
• Carbon emissions and harmful particle release during combustion.

Question 22

Coal

Answer 22

• Consists of a solid mass of hydrocarbons produced from heat and pressure.
• Diff grades - Highest is anthracite, then bituminous and finally brown.
• Cheap power source
• Used for electricity produce.

Question 23

Coal - Disadvantages:

Answer 23

• Extraction of coal destroys large amounts of vegetation and contaminates rivers with toxic mine waste.
• Burning of coal produces mercury, sulphur dioxide and nitrogen oxides that can cause acid rain.
• Contributes to CO2 Emission

Question 24

Three types of fossil fuels:

Answer 24

Oil, Coal and Natural Gas

Question 25

Natural Gas:

Answer 25

• Used mainly for heating and electricity.
• ## Cleaner, and relatively low carbon alternative to other fossil fuels.