Types of Fuels Flashcards
What are Fossil Fuels?
Fossil fuels are non-renewable resources that cannot be replenished at the rate in which they are being consumed. Meaning they will eventually be exhausted
List the 3 main Fossil Fuels
Coal, Oil and Natural Gas
What is Coal?
As wood and other plant materials are converted into coal, the carbon content increases and the proportion of oxygen and hydrogen decreases.
How is Coal converted from Chemical to Electrical energy?
- the chemical energy is in the coal
- the coal is burned creating thermal energy
- boiling water creates thermal energy from steam
- which induces mechanical energy which turns the turbine
- creating electrical energy from the generator.
What is the chemical equation for the combustion of Coal?
What is Petrol/ Crude Oil?
Crude oil (petroleum) is a mixture of hydrocarbon molecules mostly members of the homologous series of alkanes.
How is Crude Oil used?
Crude oil has useful compounds separated via fractional distillation (not pure). These fractions can be used as fuels or treated further to produce more specific products through chemical processes.
What is the chemical equation for the combustion of Petrol?
Conbustion occurs in the cars engine the hot air formed push the pistons up and down causing the car to move.
What is Petrodiesel?
Petrodiesel is a fraction of crude oil however it is stronger than petrol due to its stronger molecules than petrol.
What is Natural Gas?
Is a fossil fuel found in the deposits of earth’s crust. it can be found in gas resovoirs, in petrolleum deposits and in coal deposits.
How is Natural Gas obtained?
Natural gas is accessed through drilling as is crude oil allowing the natural gasses to flow upwards to the surface.
What is natural gas composed of?
Methane (CH4), ethane (C2H6) and propane (C3H8) along with water, sulphur, carbon dioxide and nitrogen may be present.
How is Electricity obtained from Natural Gas?
In a gas-fired power plant, methane and other alkenes are burnt to release energy. the hot gasses produced by combustion cause air to expand in a combustion turbine to generate electrical energy to support power grids. (simpler than coal-fired plant)
What is the chemical equation for the combustion of Methane?
The combustion of natural gas varies but the main equation involves methane
What are Biofuels (biochemical fuels)?
Biofuels are fuels derived from plant materials such as grains, sugarcane, and vegetable waste/oils.
What are the three main Biofuels?
Bioethanol, biogas and biodiesel.
Explain how Biofuels will Impact our Future.
Biofuels are renewable and said to have less impact on the environment than fossil fuels. The plant material used in biofuels is produced by photosynthesis, which removes CO2 from the atmosphere and produces Glucose.
What is the Chemical Equation for Photosynthesis.
Compare Biofuels and Fossil Fuels in terms of CO2 production.
While biofuels still produce CO2 into the environment the overall net impact should be less than fossil fuels
Why are biofuels considered to be Carbon neutral? (in theory)
This is because they are absorbing the same amount of CO2 in formation as is released in combustion. However, in practice it costs energy to farm, fertilise and transport biofuels so they are not likely to be carbon-neutral
What is Biogas?
Biogas is a gas that’s released by anaerobic bacteria into the breakdown of organic waste.
What are Anaerobic Bacteria
They’re bacterial that break down complex molecules contained in substances such as carbohydrates and proteins, into simpler molecular compounds, CO2 & CH4.
How is Biogas produced?
A digester is a large tank filled with anaerobic bacteria that digest (consume) the complex molecules to form biogas.
What organic waste is used for Biogas?
A range of materials such as rotting rubbish and decomposing plant material are used for biogas however the composition of biogas depends on the original material from which it was obtained and the method of decomposition.
What is Biodiesel?
Biodiesel is a mixture of esters that are produced by a chemical reaction between vegetable oil (soybeans, canola or palm oil) or animal fats and an alcohol (most commonly methanol)
What’s a triglycerides?
A triglyceride is fat and acids with a molecular structure consisting of three hydrogen chains, each attached by an ester functional group, to a backbone of three carbon atoms.
The Structure of a Biodiesel Molecule —>
What happens in a Transesterification reaction?
In a transesterification reaction the triglyceride is converted into a small molecule called glycerol and three ester molecules along with long carbon chains which are the biodiesel. Which is used for some diesel engines.
What is transesterification?
The process in which a triglyceride is converted into biodiesel by warming it with an alcohol, usually ethanol or methanol. Concentrated KOH is used as a catalyst in this reaction
Explain the issues that come with Biofuels
Because biofuels only pruduce a small percentage of Australias fuel needs, biofuel production would need to increase significantly. this will cause land degradation, the clearing of forest and bushland and ensure food supplies are maintained.
Advantages and Disadvantages of Biofuels and Fossil Fuels.
