Fuels Flashcards
(28 cards)
What is crude oil made of
A mixture of hydrocarbons
How is crude oil split
Fractional distillation
What is made at different temperatures in fractional distillation
Gases 40 C: petrol 110 C: naphtha (lighter fluid) 180 C: kerosene jet fuel 259 C: diesel 340 C: fuel oil power stations
What is complete combustion
There is plenty of oxygen
Hydrocarbon + oxygen -> carbon dioxide + water
What is incomplete combustion
Not enough oxygen
Hydrocarbon + oxygen -> carbon + carbon monoxide + carbon dioxide + water
What is carbon monoxide
Colourless, odourless gas that is poisonous and is released by faulty gas fires and boilers
What to consider when choosing a fuel
Ease of ignition
Energy value
Ash and smoke
Storage and transport t
What happens when fossil fuels are burnt
Hydrocarbon + oxygen -> carbon dioxide + water vapour
How does sulfur dioxide cause acid rain
It mixes with clouds and forms dilute sulfuric acid
What are the problems with acid rain
Makes lakes acidic killing organisms
Kills trees and damages limestone buildings
What is the problem with removing sulfur from fuels
Takes more energy and releases carbon dioxide
What are cars fitted with to reduce emissions
Catalytic converters
What are the problems with greenhouse gases (CO2 methane and water vapour)
Absorbs heat that would normally be radiated into space and sends it back to earth
How does human activity affect carbon dioxide levels
Deforestation: released when trees are burnt and organisms eat the wood which respire.
Burning fossil fuel
What is iron seeding
Iron is needed for photosynthesis so it is put into oceans to promote growth of phytoplankton which bloom and absorb CO2.
However some of these plankton are toxic and cause dead zones
What is biogas
Decomposed waste and dead plants that can be burnt to heat water in heating systems or power turbines to create electricity
Advantages of biogas
Renewable
Fairly clean fuel
Cheap
How is ethanol made
Fermenting sugars with yeast
Problems with using ethanol as fuel
Less land for food and lots of energy is needed for it but it does reduce use of fossil fuels
What is used in fuel cells
Hydrogen and oxygen
Positives of fuel cells
Doesn’t run down
More efficient than power stations (80%)
Less places for energy to be lost as heat
No pollutants
Negatives of fuel cells
Takes a lot of space to store hydrogen and is explosive
Hydrogen fuel is made from hydrocarbons from fossil fuels
What is the equation for mass of fuel burned
Initial mass of fuel and burner - final mass of fuel and burner
What is an alkane
C-C single bond
Saturated
Won’t form polymers
Methane CH4, ethane C2H6,
