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 (eg coal) or nuclear energy (eg 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. can be replaced as quickly as it is consumed. main types: bioethanol, biodiesel, biogas

Question 4

biodiesel

Answer 4

a fuel made from veg oil/animal fat, consisting of esters. typically made from reacting triglycerides with an alcohol (typically methane) in the presence of KOH as a catalyst

Question 5

biogas

Answer 5

a mixture of gases produced by the breakdown of organic matter in the absense of oxygen. consists mainly of methane and carbon dioxide

Question 6

cloud point

Answer 6

the temp at which diesel/biodiesel appear cloudy due to 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. retrieved through fracking.

Question 8

enhanced greenhouse effect

Answer 8

the warming of the temp of the earth’s surface because of an increase of greenhouse gases as a result of human activities

Question 9

flashpoint

Answer 9

the lowest temp at which the vapour of a liquid will ignite when an ignition source 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 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. maintains the temperature of earth at conditions that are suitable for life

Question 12

greenhouse gas

Answer 12

a gas which is able to absorb and then re-radiate heat radiation. contribute to the greenhouse effect. e.g co2, methane, water vapour

Question 13

hydrogen economy

Answer 13

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

Question 14

LPG (liquid petroleum gas)

Answer 14

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

Question 15

natural gas

Answer 15

a fossil fuel compromising mainly of methane which exist in the gas phase under the conditions in which they are extracted from the earth

Question 16

bioethanol

Answer 16

a biofuel made by converting starches from plants to sugars through using enzymes and then fermenting the sugars to ethanol using yeast

Question 17

renewable

Answer 17

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

Question 18

petrodiesel

Answer 18

diesel fuel derived from crude oil by fractional distillation. generally around 75% alkanes and 25% aromatic hydrocarbons. size of hydrocarbons ranges from C10-C15

Question 19

shale gas

Answer 19

natural gas which is trapped beneath shale rock deposits, usually well below the earths surface

Question 20

energy transformation

Answer 20

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

Question 21

fractional distillation

Answer 21

the separation of components in a mixture on the basis of their boiling temps

Question 22

non renewable

Answer 22

resources that are being used at a faster rate than they are being replaced