Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

developing fuels > DF 11 - other fuels > Flashcards

DF 11 - other fuels Flashcards

specification reference - (k) (u)

1
Q

how else can we tackle the problem with emissions

A

to use an alternative fuel for the car

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how much of petrol do aromatic hydrocarbons make up

A

40%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what can aromatic hydrocarbons cause

A

higher carbon monoxide, hydrocarbon and nitrogen oxide emissions and some may cause cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

which aromatic hydrocarbon usage is strictly controlled

A

benzene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

why is butane content likely to be lowered in the future

A

butane is volatile and responsible for evaporative emissions leading to ozone formations and photochemical smogs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what do butane and aromatic hydrocarbons help petrol to do

A

perform well in modern engines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what do petrol companies plan to replace aromatic hydrocarbons and butane with

A

oxygenates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are oxygenates

A

compounds containing oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is liquid petroleum gas called when used in cars

A

autogas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

where does liquid petroleum gas come from

A

the distillation of crude oil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is LPG made of

A

mixture of propane and butane in varying quantities. often 60% propane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what must happen for hydrocarbons to be used as liquids

A

they have to be kept under pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why do petrol vehicles need a larger fuel tank

A

so that the vehicle can run on more than one fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where does autogas work

A

in high performing engines and produces 20% less CO2 per mile than petrol. it also produces fewer unburnt hydrocarbons and nitrogen oxides than petrol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why does autogas release less carbon monoxide

A

because of the higher ratio of carbon to hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the advantage of using autogas

A

for vehicle owners, road and fuel taxes are lower for petrol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the disadvantage of using autogas

A

LPG filling stations are rare although numbers are increasing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is liquid natural gas mainly made up of

A

methane and comes from oil and natural gas fields

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how is methane liquefied

A

it cant be liquefied by pressure alone and must be cooled to below -160°

20
Q

why is LNG suitable for larger vehicles

A

it works in modified diesel engines

21
Q

what is the good thing about LNG

A

it has a high C:H ratio so less CO is produced and much fewer NOx than diesel

22
Q

what do schemes for developing alternating fuels for use on large scale depend on

A

long term and large scale investments in new infrastructure/ it depends on political and economic factors

23
Q

give alternatives to fossil fuels

A

biofuels, ethanol, biodiesel and hydrogen fuels

24
Q

what are biofuels and give examples

A

alternative feusl derived from renewable animal and plant materials. examples include ethanol and biodiesel

25
Q

what is ethanol made from

A

fermentation of carbohydrate crops such as sugar cane

26
Q

why cant cars easily run on ethanol alone

A

it is too volatile

27
Q

what is used instead of using pure ethanol

A

mixtures of petrol containing 15% ethanol

28
Q

why is ethanol said to be carbon neutral

A

carbon dioxide is produced in fermentation and burning the ethanol matches the carbon dioxide absorbed in the growing plant.

29
Q

how is ethanol distributed

A

energy is used to produce and distribute ethanol producing carbon dioxide if the energy comes from fossil fuels.

30
Q

what is a disadvantage of fermenting ethanol

A

the land used to grow crops for fermentation could be used to produce food instead

31
Q

what is biodiesel

A

made by chemically reacting fats and oils such as vegetable oil or animal fat with an alcohol producing fatty acid esters in a process called transesterification

32
Q

what are the advantages of using biodiesel over diesel

A
  • can be made from waste oil rather than using fossil fuel based oil
  • carbon neutral (except for the energy required to produce and distribute it)
  • some diesel vehicles can run on pure biodiesel but most on mixtures with regular diesel
  • biodegradable
  • contains virtually no sulfur so reduces SOx emissions
  • produces less particulates, carbon monoxide and hydrocarbons than petrol than diesel
33
Q

even though biodiesel produces less pollutants, what is the limitation

A

by the way in which nitrogen oxides are removed

34
Q

what is the disadvantage of using biodiesel over diesel

A

produces more nitrogen oxides than conventional fossil fuels

35
Q

give examples of biofuels

A

green diesel (derived from algae) and biogas (methane derived from animal manure and other digested organic material)

36
Q

what does hydrogen produce when combusted

A

just water
2H₂(g) + O₂(g) —-> 2H₂O(g)

37
Q

what are the advantages of using hydrogen as a fuel

A
  • renewable, can be made by electrolysis of water
  • can be stored and sent down pipelines (like methane)
  • can be used in internal combustion engines or in a fuel cell to generate electricity
  • produces no carbon dioxide, carbon monoxide or hydrocarbons when burnt
38
Q

what are the disadvantages of using hydrogen as a fuel

A
  • its production from water often depends on the use of electricity from fossil fuel power stations (though alternative energy sources for electricity are being developed)
  • less energy dense than petrol (releases less energy)
  • oxides of nitrogen are still produced at the high temperatures a hydrogen internal combustion engine runs at
39
Q

which is more cheaper than transmitting electricity

A

if systems are costed over lifetime use in terms of money and energy then distributing hydrogen by pipeline would be cheaper. hydrogen would be used to store and distribute energy

40
Q

what is being used to generate electricity in cars

A

fuel cells (on a small scale)hp

41
Q

how are fuel cells being used to generate electricity

A

they convert chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidising agent in an electrochemical cell.

42
Q

what is the fuel and product for fuel cells in cars

A

the fuel is oxygen and the product is water

43
Q

what is the problem in designing cars run on hydrogen

A

a large volume of gaseous hydrogen is needed to get the mileage equal to a fuel tank of petrol.

44
Q

what is one way to get cars to run on hydrogen

A

some way of storing hydrogen more compactly is needed

45
Q

what is the solution for getting hydrogen as a fuel for cars

A

storing it as a liquid in a high pressure fuel tank

developing fuels (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions