DF11 - Other fuels Flashcards
What 2 changes should be made to current fuel used to make it more environmentally friendly?
- Decrease in aromatic hydrocarbons used
- Decrease in butane content
What 4 things do aromatic hydrocarbons lead to?
- Higher amount of carbon monoxide emissions
- Higher amount of unburnt hydrocarbons
- Higher amount of nitrogen oxide emissions
- Cause cancer
What are the two bad qualities of butane?
- It is volatile
- Emissions cause ozone formation
- Emissions cause photochemical smog
What are aromatic hydrocarbons and butane needed for?
To help petrol perform well in modern engines
What are the two more environmentally friendly hydrocarbon fuels that should be used?
- Liquified petroleum gas (LPG)/autogas
- Liquid natural gas (LNG)
What is liquified petroleum gas (LPG)/autogas made from?
The distillation of crude oil
What is liquified petroleum gas (LPG)/autogas made up of?
A mixture of propane and butane
What are the advantages of liquified petroleum gas (LPG)/autogas? (7)
- Petrol vehicles can be easily converted to work with it
- Works in high performance engines
- Less CO2 emissions
- Less CO emissions
- Less unburnt hydrocarbons
- Less nitrogen oxide emissions
- Lower road and fuel taxes
What are the disadvantages of liquified petroleum gas (LPG)/autogas? (2)
- LPG filling stations are rare
- It needs to be kept under pressure to be stored as a liquid
What is liquid natural gas (LNG) made of?
Mainly methane
Where does liquid natural gas (LNG) come from?
Oil and natural gas fields
What is liquid natural gas (LNG) most suitable for and why?
Large vehicles, especially as it works in modified diesel engines
What are the advantages of liquid natural gas (LNG) compared to diesel?
- Less NOx emissions
- Less carbon monoxide emissions
What is the disadvantage of liquid natural gas (LNG) compared to diesel?
Cannot be liquified by pressure, must be cooled to -160 degrees c
What are the 3 types of biofuels?
- Ethanol
- Biodiesel
- Biogas
What is ethanol made from?
The fermentation of sugar from crops e.g maize
What is the advantage of ethanol?
- Carbon neutral: CO2 produced in fermentation and burning ethanol matches the CO2 absorbed in the growing plant
What are the disadvantages of using ethanol?
- Energy used to distribute and produce the ethanol (burning fossil fuels uses CO2)
- Land used to grow crops could be used to produce food instead, so food prices could go up
How is biodiesel made?
Chemically reacting fats and oils e.g vegetable oils/animal fats with an alcohol producing fatty acid esters (trans-esterifcation)
What are the advantages of biodiesel?
- It can be made from waste oil instead of using fossil fuel based oil
- Carbon neutral
- Biodegradable if spilled
- Virtually no sulfur - reduces sulfur oxides
- Less particulates, CO, unburnt hydrocarbons
What are the disadvantages of biodiesel?
- Produces more nitrogen oxides than conventional fossil fuels
- Engines would have to be modified
What is biogas produced from?
The breakdown of organic waste matter
What two ways can hydrogen be used to generate energy?
- Burnt in a modified engine
- Used in a fuel cell
What do fuel cells used for?
To generate electricity on a small scale by converting chemical energy from a fuel into electrical energy
How is chemical energy generated in a fuel cell?
Through the chemical reaction with oxygen/an oxidising agent in electrochemical cells
Give the equation for the combustion of hydrogen.
2H2(g)+O2(g)====> 2H2O (g)
How is hydrogen obtained?
From seawater using the hydrolysis of water
Why is hydrogen an “energy carrier” rather than an “energy source”?
It takes energy to extract it
What are the advantages of using hydrogen as a fuel? (5)
- Renewable - can be made from the electrolysis of water
- Can be stored and sent down in pipelines
- Can be used in internal combustion engines and fuel cells
- Produces no CO2, CO or unused hydrocarbons when burnt, just water
What are the disadvantages of using hydrogen as a fuel? (6)
- Production from water depends on the use of electricity
- Less energy dense than petrol, less energy per gram so a larger amount of hydrogen is needed to get the mileage equivalent of petrol
- Oxides of nitrogen are still produced at the high temperatures of a hydrogen internal combustion engine
- Highly flammable so not easy to store
- Has to be liquified due to the low energy to volume ratio of hydrogen gas
- Needs a whole new infrastructure for the fuel
What should future fuels aim to do? (2)
- Reduce emissions + pollution and therefore global warming
- Be much more economical
Give 2 reasons the government needs energy security
- Increasing competition from other countries for energy sources means an increase in price
- Supplies from other countries could be disrupted due to political issues
Give 5 methods for achieving energy security,
- Encouraging the public and industry to become more energy efficient
- Continuing to make use of coal, oil and gas reserves
- Creating financial incentives to reduce CO2 emissions
- Using more renewable energy
- Creating research of new energy sources
