Chapter 1 Fuels

Question 1

Fuel

Answer 1

A substance with stored energy which can be released relatively easily for use as heat or power. The stored energy can be in the form of chemical energy (eg coal) or nuclear energy (eg uranium.

Question 2

Fossil fuel

Answer 2

A fuel made of organic matter of ancient origin which cannot be replaced as quickly as it is consumed. The main fossil fuels are coal, crude oil, natural gas and coal seam gas.

Question 3

Biofuel

Answer 3

A fuel made from organic material of recent origin which can be replaced as quickly as it is consumed. The main types are biodiesel, bioethanol and biogas.

Question 4

Biodiesel

Answer 4

A fuel made from vegetable oil or animal fat, consisting of long-chain alkyl esters. Typically made by reacting triglycerides with an alcohol, typically methanol in the presence of KOH as a catalyst.

Question 5

Bioethanol

Answer 5

A biofuel made by converting starches from plants into sugars using enzymes and then fermenting the sugars into ethanol using yeast.

Question 6

Biogas

Answer 6

A mixture of gases produced by the breakdown of organic matter in the absence of oxygen. Consists typically of a mixture of methane and carbon dioxide.

Question 7

Cloud point

Answer 7

The temperature at which a diesel or biofuel appears cloudy because of the formation of small crystals and thus begins to freeze. These crystals thicken the fuel and clog filters and fuel injectors in engines.

Question 8

Coal Seam gas

Answer 8

Natural gas trapped by pressure on the surface of a coal seam.

Question 9

Enhanced greenhouse effect

Answer 9

The warming of temperature of the Earth’s surface because of an increase in concentration of greenhouse gases as a result of human activities.

Question 10

Flashpoint

Answer 10

The lowest temperature at which the vapour of a liquid will ignite when an ignition source (flame) is applied to it.

Question 11

Fracking

Answer 11

The process of injecting sand, water or chemicals at high pressure into coal or rock to release trapped natural gas.

Question 12

Greenhouse effect

Answer 12

The process by which heat radiation from Earth’s surface is absorbed and re-radiated by gases in the atmosphere. The greenhouse effect maintains the temperature of Earth at conditions which are suitable for life.

Question 13

Greenhouse gas

Answer 13

A gas which is able to absorb and re-radiate heat radiation. Theses gases contribute to the Greenhouse effect. E.g. CO2, CH4, H2O(g)

Question 14

Hydrogen economy

Answer 14

A proposed system of delivering energy for society using hydrogen as a source of energy.

Question 15

LPG

Answer 15

A mixture of propane and butane that is separated from natural gas or crude oil. It is stored under pressure to liquefy the propane and butane.

Question 16

Natural gas

Answer 16

A fossil fuel comprising of mainly methane which exist in the gas phase under the conditions in which they are extracted from Earth.

Question 17

Renewable

Answer 17

Renewable resources are not in limited supply e.g. wind power or can be replaced as quickly as they are consumed (e.g. biofuels such as biodiesel, bioethanol or biogas)

Question 18

Petrodiesel

Answer 18

Diesel fuel derived from crude oil from fractional distillation. The composition of petrodiesel varies, but it is generally around 75% alkanes and 25% aromatic hydrocarbons. The size of hydrocarbons ranges from C10 to C15.

Question 19

Shale gas

Answer 19

Natural gas trapped beneath shale rock deposits, usually well below the Earth’s surface

Question 20

Energy transformation

Answer 20

The process of converting one form of energy into another form of energy e.g. heat E into mechanical E

Question 21

Fractional distillaition

Answer 21

The separation of the components in a mixture on the basis of their boiling temp

Question 22

Non-renewable

Answer 22

Non-renewable energy resources are those which are being used at a faster rate than they are being replaced.

Question 23

Viscosity

Answer 23

measures the resistance of a substance to flow

Question 24

Hygroscopic

Answer 24

A tendency to absorb more moisture from the air