DF11 - Other fuels

Question 1

What 2 changes should be made to current fuel used to make it more environmentally friendly?

Answer 1

• Decrease in aromatic hydrocarbons used

- Decrease in butane content

Question 2

What 4 things do aromatic hydrocarbons lead to?

Answer 2

• Higher amount of carbon monoxide emissions
• Higher amount of unburnt hydrocarbons
• Higher amount of nitrogen oxide emissions
• Cause cancer

Question 3

What are the two bad qualities of butane?

Answer 3

• It is volatile
• Emissions cause ozone formation
• Emissions cause photochemical smog

Question 4

What are aromatic hydrocarbons and butane needed for?

Answer 4

To help petrol perform well in modern engines

Question 5

What are the two more environmentally friendly hydrocarbon fuels that should be used?

Answer 5

• Liquified petroleum gas (LPG)/autogas

- Liquid natural gas (LNG)

Question 6

What is liquified petroleum gas (LPG)/autogas made from?

Answer 6

The distillation of crude oil

Question 7

What is liquified petroleum gas (LPG)/autogas made up of?

Answer 7

A mixture of propane and butane

Question 8

What are the advantages of liquified petroleum gas (LPG)/autogas? (7)

Answer 8

• Petrol vehicles can be easily converted to work with it
• Works in high performance engines
• Less CO2 emissions
• Less CO emissions
• Less unburnt hydrocarbons
• Less nitrogen oxide emissions
• Lower road and fuel taxes

Question 9

What are the disadvantages of liquified petroleum gas (LPG)/autogas? (2)

Answer 9

• LPG filling stations are rare

- It needs to be kept under pressure to be stored as a liquid

Question 10

What is liquid natural gas (LNG) made of?

Answer 10

Mainly methane

Question 11

Where does liquid natural gas (LNG) come from?

Answer 11

Oil and natural gas fields

Question 12

What is liquid natural gas (LNG) most suitable for and why?

Answer 12

Large vehicles, especially as it works in modified diesel engines

Question 13

What are the advantages of liquid natural gas (LNG) compared to diesel?

Answer 13

• Less NOx emissions

- Less carbon monoxide emissions

Question 14

What is the disadvantage of liquid natural gas (LNG) compared to diesel?

Answer 14

Cannot be liquified by pressure, must be cooled to -160 degrees c

Question 15

What are the 3 types of biofuels?

Answer 15

• Ethanol
• Biodiesel
• Biogas

Question 16

What is ethanol made from?

Answer 16

The fermentation of sugar from crops e.g maize

Question 17

What is the advantage of ethanol?

Answer 17

• Carbon neutral: CO2 produced in fermentation and burning ethanol matches the CO2 absorbed in the growing plant

Question 18

What are the disadvantages of using ethanol?

Answer 18

• Energy used to distribute and produce the ethanol (burning fossil fuels uses CO2)
• Land used to grow crops could be used to produce food instead, so food prices could go up

Question 19

How is biodiesel made?

Answer 19

Chemically reacting fats and oils e.g vegetable oils/animal fats with an alcohol producing fatty acid esters (trans-esterifcation)

Question 20

What are the advantages of biodiesel?

Answer 20

• It can be made from waste oil instead of using fossil fuel based oil
• Carbon neutral
• Biodegradable if spilled
• Virtually no sulfur - reduces sulfur oxides
• Less particulates, CO, unburnt hydrocarbons

Question 21

What are the disadvantages of biodiesel?

Answer 21

• Produces more nitrogen oxides than conventional fossil fuels
• Engines would have to be modified

Question 22

What is biogas produced from?

Answer 22

The breakdown of organic waste matter

Question 23

What two ways can hydrogen be used to generate energy?

Answer 23

• Burnt in a modified engine

- Used in a fuel cell

Question 24

What do fuel cells used for?

Answer 24

To generate electricity on a small scale by converting chemical energy from a fuel into electrical energy

Question 25

How is chemical energy generated in a fuel cell?

Answer 25

Through the chemical reaction with oxygen/an oxidising agent in electrochemical cells

Question 26

Give the equation for the combustion of hydrogen.

Answer 26

2H2(g)+O2(g)====> 2H2O (g)

Question 27

How is hydrogen obtained?

Answer 27

From seawater using the hydrolysis of water

Question 28

Why is hydrogen an “energy carrier” rather than an “energy source”?

Answer 28

It takes energy to extract it

Question 29

What are the advantages of using hydrogen as a fuel? (5)

Answer 29

• Renewable - can be made from the electrolysis of water
• Can be stored and sent down in pipelines
• Can be used in internal combustion engines and fuel cells
• Produces no CO2, CO or unused hydrocarbons when burnt, just water

Question 30

What are the disadvantages of using hydrogen as a fuel? (6)

Answer 30

• Production from water depends on the use of electricity
• Less energy dense than petrol, less energy per gram so a larger amount of hydrogen is needed to get the mileage equivalent of petrol
• Oxides of nitrogen are still produced at the high temperatures of a hydrogen internal combustion engine
• Highly flammable so not easy to store
• Has to be liquified due to the low energy to volume ratio of hydrogen gas
• Needs a whole new infrastructure for the fuel

Question 31

What should future fuels aim to do? (2)

Answer 31

• Reduce emissions + pollution and therefore global warming

- Be much more economical

Question 32

Give 2 reasons the government needs energy security

Answer 32

• Increasing competition from other countries for energy sources means an increase in price
• Supplies from other countries could be disrupted due to political issues

Question 33

Give 5 methods for achieving energy security,

Answer 33

• Encouraging the public and industry to become more energy efficient
• Continuing to make use of coal, oil and gas reserves
• Creating financial incentives to reduce CO2 emissions
• Using more renewable energy
• Creating research of new energy sources