Fuels & Energy

Question 1

Fossil fuel

Answer 1

natural fuel that is formed in the earth from plant or animal remains (non-renewable)

Question 2

fossil fuel examples

Answer 2

e.g. methane, octane, CSG, liquid petroleum gas (LPG), diesel/petrodiesel

Question 3

Coal

Answer 3

combustible fossil fuel formed by the partial decay of plant matter

Question 4

Petrodiesel

Answer 4

liquid hydrocarbon fossil fuel obtained from crude oil

Question 5

Natural gas

Answer 5

fossil fuel consisting largely of hydrocarbons

Question 6

Coal Seam Gas

Answer 6

natural gas sourced from coal deposits

Question 7

Greenhouse effect

Answer 7

process of warming of the Earth’s lower atmosphere due to the increased quantities of gases, like carbon dioxide, water vapour and methane, in the air

Question 8

Non-renewable resource

Answer 8

resource that cannot be replenished as quickly as it is being consumed

Question 9

Biofuel

Answer 9

fuel sourced from organic matter (plant matter – biomass)
- renewable
- carbon neutral

Question 10

why do biofuels have no or little impact on atmospheric CO2?

Answer 10

approx. 0 net impact on atmospheric CO2
(plant = photosynth –> absorbs CO2 from atmosphere, plant matter = converted into biofuel, biofuel combusts = CO2 back in atmosphere)

Question 11

biofuel examples

Answer 11

e.g. biogas, bioethanol, biodiesel

Question 12

Biogas

Answer 12

gaseous fuel produced by the anaerobic breakdown of organic matter

Question 13

Bioethanol

Answer 13

fuel produced by the fermentation of glucose in organic matter

Question 14

Biodiesel

Answer 14

fuel produced by the esterification of fats and oils in organic matter

Question 15

Carbon neutral

Answer 15

fuel which does not result in a net production of carbon dioxide from sourcing or consumption

Question 16

Fermentation

Answer 16

breakdown of a substance in the presence of microorganisms such as yeast

Question 17

Renewable resource

Answer 17

resource capable of being replenished by natural processes as quickly or faster than it is being consumed

Question 18

Transesterification

Answer 18

reaction that produces biodiesel

Question 19

Triglyceride

Answer 19

fat or oil composed of three fatty acid tails and a glycerol backbone

Question 20

Yeast

Answer 20

variety of microorganism which converts glucose into ethanol

Question 21

Fuel

Answer 21

a substance that burns in air or oxygen to release a usable amount of energy

Question 22

fuel characteristics

Answer 22

• low bp
• low flashpoint
• high flammability
  –> easy to combust + release large amounts of energy (exothermic)

Question 23

Flashpoint

Answer 23

lowest temp at which a particular organic compound gives off sufficient vapour to ignite in air
- influenced by structure + intermolecular bonds

• smaller hydrocarbons = weaker intermolec forces + more easily vaporised = lower flashpoints + more flammable
• flashpoint below room temp. = safety hazard

Question 24

Storage of fuels

Answer 24

• away from naked flames (flammable)
• well ventilated areas (suffocation)
• (safety measures e.g. fire extinguishers + blankets)

Question 25

Bonding & Properties

Answer 25

• size of molecules involved (structure + func groups)
• increasing bp => increasing dispersion forces (dep. on size of molecule)
• hydrogen bonds => higher bp + soluble in water
• type of intermolecular bonds (func groups)
• properties: e.g. bp, flashpoint, viscosity + solubility

Question 26

Why do straight chains have higher flashpoints?

Answer 26

straight chains fit together better
= larger SA in contact w each other
= more dispersion forces
(form dispersion forces across a larger SA)
= more energy to overcome
–> higher flashpoint

Question 27

Flammable liquid

Answer 27

any liquid with a flashpoint below 37.8*C
- ignite + burn easily at lower temps (liquid = X burn, mixture of vapours burns in oxygen in air)

Question 28

Combustible liquid

Answer 28

flashpoint 37.8*C or above = combustible => harder to ignite
- burn at temps above room temp

Question 29

Vaporisation rate

Answer 29

increases as temp increases
- flammable + combustible liquids = more hazardous at temps higher than room temp

Question 30

Renewable fuels

Answer 30

can be replenished at a rate similar to which they are being used

• often breakdown of plant/animal material as a basis for fuel
• plants grown rel short time = converted into desired product for use in fuel

Question 31

renewable fuels examples

Answer 31

e.g.
- biogas (fermentation of waste products/plant material – mainly methane +CO2)
- bioethanol (fermentation of glucose)
- biodiesel (methyl ester – fatty acid + methanol)

Question 32

Non-renewable fuels

Answer 32

not able to be replenished at a rate similar to which they are being used

• finite

Question 33

non-renewable fuels examples

Answer 33

• e.g. fossil fuels

Question 34

Renewable energy sources

Answer 34

not produced faster than used by society.

Question 35

renewable energy source examples

Answer 35

e.g.
solar energy
hydro-electricity
tidal power + wave power
wind turbine energy
geothermal energy
biofuels

Question 36

Non-renewable energy sources

Answer 36

used up faster than produced on earth.

• limited supply

Question 37

non-renewable energy source e.g.

Answer 37

e.g.
fossil fuels
nuclear energy sources