Chapter 1 - Choosing Fuels

Question 1

What is a fuel?

Answer 1

A substance used to produce energy or power, usually by combustion

Question 2

What is a renewable energy?

Answer 2

A source or fuel that can be replenished by natural means and can be manufactured faster than they are used by society.

Question 3

Examples of renewable energy

Answer 3

Solar, Wind, Hydro

Biofuels

Question 4

What is a non-renewable energy?

Answer 4

A source or fuel that cannot be replenished faster than they are used by society.

Question 5

examples of non-renewable energy

Answer 5

Coal, Petroleum, Natural Gas

Question 6

How is bioethanol created?

Answer 6

By the fermentation of sugars found in plant and animal waste. These sugars include Molasses and Starch.

Question 7

Pros/Cons of Bioethanol

Answer 7

• less pollutant emission as it is made from natural waste
• renewable

-less energy is released relative to petrol and it is quite expensive

Question 8

How is biodiesel created?

Answer 8

Fatty acids in products such as vegetable oils, animal fats and cooking oil undergo transesterification to produce biodiesel

Question 9

Pros/Cons of Biodiesel

Answer 9

• Biodegradable less pollutant emissions like SO2
• renewable
• High viscosity may cause it to ‘gel’ in cold climates thus not suitable
• crops take up space which could be used for food crops

Question 10

How is Biogas created?

Answer 10

Biogas is a mixture of gases, mainly methane, that are produced by the anaerobic fermentation of animal and plant waste.

Question 11

Pros/Cons of biogas

Answer 11

• Can be produced on a large scale
• can generate many types of energy
• low energy released
• no cons

Question 12

What is kinetic energy?

Answer 12

Energy associated with movement, in doing work.

Question 13

What is potential energy?

Answer 13

Energy that is stored, ready to do work.

Question 14

What is energy?

Answer 14

Energy is defined as the ability to do work. It is measured in the unit “joules”.

Question 15

What is a thermochemical equation?

Answer 15

A chemical equation that also shows the quantity of heat energy given out or absorbed when a mole of a substance is burned.

Question 16

What is the Law of Conservation of Energy?

Answer 16

Energy is neither created or destroyed but transferred into other forms

Question 17

What affect does many transfers of energy have?

Answer 17

Although quantity of energy can stay the same the quality becomes worse. Some energy is lost as heat etc.

Question 18

What is energy efficiency?

Answer 18

How efficient a substance is refers to how much of it can actually be transferred into a new form of energy.

Question 19

Energy Efficiency formula

Answer 19

(energy obtained/energy that was available) x 100

Question 20

Pros/Cons of oil

Answer 20

-wide range of uses

• non-renewable
• pollution

Question 21

Pros/Cons of coal

Answer 21

• easily mined
• source of revenue for AUS
• -global warming
• non-renewable

Question 22

Pros/Cons of Natural gas

Answer 22

• high efficiency
• moderate cost
• non-renewable
• pollution

Question 23

What fuel has the highest heat content per gram?

Answer 23

Natural Gas/Methane

Question 24

What is the enhanced greenhouse effect

Answer 24

“Enhanced” refers to pollutant emissions having an affect on the world and affecting global warming, the ozone layer etc.

“Not enhanced” refers to water being the largest contribution in the form of clouds reflecting sunlight onto the ozone layer.

Question 25

PD AND BD

Intermolecular bonding

Answer 25

PD
Dispersion forces (non-polar)

BD
Dispersion and dipole (ester group)

Question 26

PD AND BD

Viscosity

Answer 26

BD

Has a higher viscosity than PD and therefore may tend to ‘gel’ in cold climates and be rendered useless.

Question 27

PD AND BD

Cloud Point

Answer 27

Cloud Point is the lowest temperature at which crystals start to form

BD
Has a higher cloud point which makes it unsuitable for cold climates.

Question 28

PD AND BD

Hydroscopic

Answer 28

PD
Slightly

BD
More hydroscopic than PD which leads to lower fuel efficiency.

Question 29

PD AND BD

Energy Content

Answer 29

PD

Has a higher energy density than bio diesel.

Question 30

PD AND BD

Source

Answer 30

PD
Crude oil –> fractional distillation

BD
Transesterification from triglycerides +ethanol/methanol
85 deg C