Topic 8- Fuels and Earth Science Flashcards
Fractional Distillation
The process in which crude oil is separated
Crude oil
Naturally occuring oil made out of hydrocarbons
Hkw is crude oil formed
- Small animals doe
- They are fossilied at high temperatures and pressures
- Process takes millions of years
What is the structure of hydrocarbons?
Rings or chains
How does fractional distillation occur?
- The oil is heated until it is almost a gas
- The smaller hydrocarbons float towards the top of the column
- The longer chains collect at the bottom
Diiferent types of hydrocarbons
- Gases/LPG
- Petrol
- Naptha
- Kerosene
- Diesel Oil
- Fuel Oil
- Bitumen
Uses of LPG
Heating/Domestic Cooking
Uses of petrol
Cars
Uses of Naptha
Molotovs
Uses of Kerosene
Plane fuel
Diesel oil
Large vehicles
Fuel oil
Large ships or power stations
Bitumen
Tarmac
Homologous Series
A series that share similar characteristics
Hydrocarbon series
Methane = CH4 Ethane = C2H6 Propane = C4H8 Butane = C6H10 Monkeys Eat Peanut Butter
Properties of hydrocarbons
- Held together by intermolecular forces
- Shirter hydrocarbons are easy to ignite
- Gas molecules mix with oxygen to ignite
- Larger hydrocarbons are usually liquid and harder to ignite
Viscosity
How easily something flows
Viscosity of hydrocarbons
- The stronger the intermolecular force, the lower the viscosity
- Fractions containing longer hydrocarbons have a lower viscosity meaning it is harder for them to flow
Pollutants
Gases that cause harm to the natural environment
What produces pollutants
Incomplete Combustion
How does an incomplete combustion occur
If there is not enough oxygen for the combustion to occur. This can happen in appliances such as boilers. The products contain less oxygen than carbon dioxide. This is carbon monoxide
Effects of carbon monoxide
- Asphyxiation
- Can lead to fainting, comas and death
Sulfur Dioxide
- Sulfur dioxide is released in the burning of fossil fuel for energy
- Comes from sulfur impurities in fossil fuels
- When it mixes with clouds, a dilute sulfuric acid forms
- Leads to acid rain and the killing of plant and animal life
Oxides of Nitrogen
- Pollutant
- Caused by oxygen and nitrogen reacting
- Creates photochemical smog
- Air pollution and leads to breathing difficulties
Hydrogen as a fuel
Hydrogen can be used as a renewable power for vehicles as it is used in hydrogen power cells
Pros of hydrogen as a fuel
- Very clean
- Only waste product is water
- Renewable
- Can be obtained from the waste products
Cons of hydrogen a fuel
- Expensive equiment is needed
- Often uses energy from another source to manufacture
- It is hard to store
Cracking
The splitting up of hydrocarbons to meet demand for shorter chains of hyrdocarbons
Process of cracking
- Vaproes hydrocarbons are passed over a catalyst at 400-700 defrees and at 70 atm
- The catalyst used is aluminium oxide
- For example C20H42 goes to CH4 and C19H40
Atmosphere - Phase One
- The Earth’s surface was originally molten with no atmosphere
- The surface eventually cooled and a crust formed. Volcanoes continued to erupt which produced carbon dioxide, steam, methane and ammonia
- When the volcanoes stopped erupting, there was little oxygen
- Water vapour condensed to form the Earth’s oceans
Atmosphere - Phase 2
- Early Carbon Dioxide dissolved into the oceans
- Nitrogen was them releases into the atmosphere by denitrifying bacteria and ammonia reacting with oxygen
- Nitrogen is not very reactive so it did not break down
- Green plants evolved, they photosynthesised to add oxygen and remove carbon dioxide
- Much Carbon dioxide was eventually trapped in fossil fuels and sedimentary rocks
Atmosphere - Phase 3
- Build up of oxygen eventually killed off early organisms that could not tolerate it
- This allowed evolution to occur and produce more complex organisms
- The build up of oxygen eventually created the Ozone Layer to block out harmful UV rays from space
Test for Oxygen
Put a glowing splint in the substance and it should be relit
Causes of the Greenhouse Effect
- Due to the increase in population, more people are respiring and more carbon dioxide is being produced
- More energy is required for the surge of people. The increased energy means that more carbon dioxide is being produced from the burning of fossil fuels
- An increase in housing and food means more carbon dioxide is being produced
- Less carbon dioxide being taken in due to deforestation
- Volcanoes
Process of the greenhouse effect
- The earth radiates some of the heat radiation it absorbs as IR
- Some IR radiation is aborbed by greenhouse gases
- Some of the IR is reflected back to Earth by greenhouse gases
- Some IR is emitted back to space
- This absorbtion and reflection warms the Earth
How IR enters the atmosphere
- The sun emits IR as EM waves
- Some EM radiation passes through the atmosphere
- Shorter wavelengths are absorbed by the Earth
Examples of Greenhouse gases
Carbon Dioxide
Water Vapour
Methane
Factor effecting the Greenhouse effect
If there is a higher concentration of gases, there will be more heat
Climate Change
A change in average temperatures in the world
Causes of climate change
Increases in greenhouse gases
Global Warming
A thpe of coimate change that can affect other types of climate change such as changes in rainfall. Can also cause severe flooding due to polar ice caps melting
Historical Data
- Current levels of carbon dioxide are easy to measure due to measurings taken all over the world
- Historical Data is much less accurate as fewer readings will have been taken
- There are other ways to meausre past CO2 levels such as tree rongs, gas bubbles in ice sheets and fossils.
- These are less precise and less representative of the world
Reducing fossil fuels
- Cutting down on fossil fuels will reduce carbon dioxide levels in the atmosphere
- This could slow down the negative effects of climate change
- The UK have already put plans in place to reduce climate change
- Renewable energy will be better
