Ch.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 (e.g. coal) or nuclear energy (e.g. uranium).

Question 2

Fossil Fuel

Answer 2

A fuel made from 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. This fuel can generally be replaced as quickly as it is consumed. The main types of biofuels are biodiesel, biogas and bioethanol.

Question 4

Biodiesel

Answer 4

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

Question 5

Biogas

Answer 5

A mixture of gases produced by the breakdown of organic matter via anaerobic bacteria, in the absence of oxygen. Biogas consists typically mainly of a mixture of methane and carbon dioxide.

Question 6

Cloud point

Answer 6

The temperature at which diesel or biodiesel 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 7

Coal seam gas

Answer 7

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

Question 8

Enhanced greenhouse effect

Answer 8

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

Question 9

Flashpoint

Answer 9

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

Question 10

Fracking

Answer 10

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

Question 11

Greenhouse effect

Answer 11

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

Question 12

Greenhouse gas

Answer 12

A gas that is able to absorb and then re-radiate heat radiation. These gases contribute to the Greenhouse effect. Examples are carbon dioxide, methane, and water vapor.

Question 13

Hydrogen economy

Answer 13

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

Question 14

LPG (liquified petroleum gas)

Answer 14

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 15

Natural gas

Answer 15

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

Question 16

Bioethanol

Answer 16

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

Question 17

Petrodiesel

Answer 17

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

Question 18

Shale gas

Answer 18

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

Question 19

Energy transformation

Answer 19

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

Question 20

Fractional distillation

Answer 20

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