Fuels Flashcards
What’s the definition of a fuel? and what are it’s types
Fuel is a substance with stored energy that can be released relatively easily for use as heat or power. The stored energy can be in the form of chemical energy (coal) or nuclear energy (uranium). There are fossil fuels (non-renewable) and biofuels (renewable).
What are fossil fuels and how are formed?
They are fuels that are produced over a long period of time from broken organic material. This process can take millions of years which is why it’s considered non-renewable . Eg: Coal, crude oil…etc. It starts with plants/animals and organisms buried deep under ground and undergoing complex stages to break down.
What is the flashpoint of the fuel?
The flashpoint is the lowest temperature at which vapours of a fuel will ignite. The smaller the dispersion forces, the lower the flashpoint.
How does coal form?
Coal is formed underground from decaying vegetation, it is a combination of carbon, oxygen, hydrogen, nitrogen, sulfur and other elements. The carbon content increases and the hydrogen and oxygen content decreases as it is deeper in the ground. It progressively becomes peat (60%), brown coal (70%) and then black coal (the deeper the coal, the higher is it’s heat value).
What is Crude oil and how is it formed?
Crude oil is a mixture of hydrocarbon molecules that are mostly members of the homologous group.
Explain the term Fractional distillation
It’s a method used to separate crude oil into a range of fractions, this doesn’t produce pure substances, each fraction is still a mixture of hydrocarbons that can be used as fuels, or treated further to produce more specific products.
What is Natural Gas?
Natural Gases is a fossil fuel (non-renewable). It is mainly composed of methane and hydrocarbons such as propane and ethane. As well as water, co2, sulfur…etc.
True or False: Ethanol, CH3 CH2 OH, can be classified as a fossil fuel because it can be produced from crude oil.
True, Ethene (CH2=CH2), is used to produce ethanol (by reaction with steam in the presence of an acid catalyst)
Where can Natural Gas be found?
- Coal deposits: Coal seams usually contain water and the pressure of water keeps the gas absorbed to the coal surface. When found like this (Coal Seam Gas) CSG.
- trapped in shale rocks, known as shale gas.
- components of petroleum deposits.
Why are fossil fuels a good fuel source?
Most energy is generated by fossil fuels. This is because there structure is fairly stable, and won’t explode
when burnt and converted to carbon dioxide and water, like a lot of other materials. The products they
form have a lot less energy then the original hydrocarbon chains, which mean a lot of energy is, released
which is what is utilised for things like electricity and heat.
Describe the process of Electricity Production by Coal.
- Coal is burnt producing thermal energy
- The burnt coal is used to boil water, which transforms thermal energy from the burning is then transformed to thermal energy as steam.
- the steam goes through a turbine which converts the thermal energy to mechanical energy as it spins.
- Electricity is produced from the generator that spins the turbine, mechanical energy is converted to electricity.
What is the difference between renewable and non-renewable fuel?
A Non-Renewable fuel:
- Energy stored within the bonds of fossil fuels is essentially trapped solar energy, coming from buildup plants that have once carried out photosynthesis.
- It cannot be produced as fast as it’s consumed.
- It takes millions of years to produce from decomposed plants.
Renewable fuels:
- can be produced as fast as it’s consumed
- formed by the anerobic breakdown of organic waste.
The difference between renewable and non-renewable energy?
- Non-renewable energy has higher content energy and is fairly inexpensive but produces greenhouse gases and the digging to extract it will cause biodiversity.
Renewable energy produces less greenhouse gases and won’t run out, however, it is costly and has low energy content as well as it needs a lot of water and land for crops.
What is the main component of Coal?
plant matter, made up of roughly 50% carbon.
What is a biofuel?
A renewable fuel that can be produced from crops and other organic materials. (living systems)
