Chapter 1 Fuels Flashcards
Fuel
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.
Fossil fuel
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.
Biofuel
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.
Biodiesel
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.
Bioethanol
A biofuel made by converting starches from plants into sugars using enzymes and then fermenting the sugars into ethanol using yeast.
Biogas
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.
Cloud point
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.
Coal Seam gas
Natural gas trapped by pressure on the surface of a coal seam.
Enhanced greenhouse effect
The warming of temperature of the Earth’s surface because of an increase in concentration of greenhouse gases as a result of human activities.
Flashpoint
The lowest temperature at which the vapour of a liquid will ignite when an ignition source (flame) is applied to it.
Fracking
The process of injecting sand, water or chemicals at high pressure into coal or rock to release trapped natural gas.
Greenhouse effect
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.
Greenhouse gas
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)
Hydrogen economy
A proposed system of delivering energy for society using hydrogen as a source of energy.
LPG
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.
Natural gas
A fossil fuel comprising of mainly methane which exist in the gas phase under the conditions in which they are extracted from Earth.
Renewable
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)
Petrodiesel
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.
Shale gas
Natural gas trapped beneath shale rock deposits, usually well below the Earth’s surface
Energy transformation
The process of converting one form of energy into another form of energy e.g. heat E into mechanical E
Fractional distillaition
The separation of the components in a mixture on the basis of their boiling temp
Non-renewable
Non-renewable energy resources are those which are being used at a faster rate than they are being replaced.
Viscosity
measures the resistance of a substance to flow
Hygroscopic
A tendency to absorb more moisture from the air
