C1 - topic 5 - biofuels and fuel cells Flashcards
what are micro organisms used to do?
decompose living organisms waste of dead plants to create biogas which can be used as fuel
what can biogas be used as?
fuel
biogas can be burned to do what?
heat water
used in central heating systems
power a turbine - generate electricity
was is an advantage of biogas over fossil fuels?
it’s renewable so it won’t run out
why is biogas renewable?
the plants which are decomposed to make biogas can be replaced quickly with new crops
what is another advantage of biogas?
dead plants need to make biogas photosynthesised when alive, removing Carbon dioxide from the atmosphere which balances out the release of Carbon dioxide from burning the biogas
what is biogas?
70% methane
30% Carbon dioxide
why is biogas a fairly clean fuel?
it doesn’t produces as many small particles (particulates) of significant amount of sulfur dioxide and oxides of nitrogen (causes of acid rain)
why is biogas cheap?
because the raw materials are cheap and readily available
what is alcohol made from?
sugar
what is a type of alcohol that can be used as fuel?
ethanol
what does ethanol burn to give?
Carbon dioxide and water
what kind of sugar materials can be used to make alcohol?
sugar cane and sugar beet
what is gasohol?
10% ethanol m90% petrol
what is a use of gasohol?
some cars can be adapted to rub on a mixture of ethanol and petrol
what is a disadvantage of gasohol?
large amounts of land are needed to grow the crops used to produce ethanol so there would be less land available to grow food
what is an advantage of gasohol?
the crops needed for ethanol production absorbs Carbon dioxide from the atmosphere in photosynthesis whilst growing which contributes to balancing out the release of carbon dioxide when the gasohol is burnt
what does using googol instead of pure petrol mean?
less crude oil being used
why isn’t gasohol the perfect solution?
distilling the ethanol after fermentation needs a lot of energy
what two elements give out energy when they react?
hydrogen and oxygen
when hydrogen and oxygen react what is produced?
water
what is released during the reaction between hydrogen and oxygen?
energy
what is useful about reacting oxygen and hydrogen?
it produces energy but doesn’t procure any nasty pollutants
what do fuel cells use to produce electrical energy?
fuel and oxygen