C1.28a Making biodiesel Name
Class
Date
Biodiesel can be made from vegetable oils, even from used cooking oil. You can make biodiesel in the laboratory. Biodiesel is a better fuel than vegetable oil, which does not burn easily in an engine.
Apparatus 10 cm3 measuring cylinder
2 x test tubes
cooking oil
stoppered tube containing potassium hydroxide in methanol
small beaker
eye protection
teat pipette
access to a balance
Health and safety ●
Wear eye protection (safety goggles)
●
Methanol is highly flammable and toxic, and potassium hydroxide is corrosive – if you get any of this mixture on your hands wash them under running water straight away.
●
Do not shake the test tube in step E (the mixture may squirt out if you do).
Method A Put a test tube in a small beaker on a balance and zero the balance. B Add 10 cm3 of cooking oil to the test tube and read the balance. This is the mass of vegetable oil you started with – write down the mass. C Measure out 15 cm3 of methanol and add it to the cooking oil. D Add the contents of the stoppered tube to the cooking oil. Use the stopper from this tube to seal the top of the tube containing the mixture. E Turn the tube upside down slowly, and then turn it the right way up again. Keep a finger on the stopper while you do this to make sure it does not come out. Keep doing this until you have turned the test tube at least 30 times. F
Stand the test tube in the beaker again and watch what happens.
G Allow the mixture to stand until it has completely separated into two layers. You may need to carry out the rest of the method in the next lesson. H Put a test tube in a small beaker on a balance and zero the balance. I
Use a clean teat pipette to remove the top layer of your mixture and put it into the test tube on the balance. This is your biodiesel. The reading on the balance shows how much biodiesel you have made. Write down the reading on the balance.
Questions 1
a
What mass of oil did you start with?
b
What mass of biodiesel did you produce?
c
What percentage of your starting mass was this?
Activity based on a laboratory practical activity devised by CLEAPSS, reproduced here with permission. © Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.28b Alternatives to fossil fuels You do not need to remember the details on this sheet for your exam, but you could be asked to apply your knowledge to unfamiliar situations. The cards below describe various alternatives to using fossil fuels such as coal, oil and gas. Use the cards to help you to answer these questions. Why is petrol, not coal, used in cars? (Hint: think about how petrol is stored in a car and how it enters the engine.)
1 2
3
Which alternative fuels are produced using: a
left-over materials
b
waste materials
c
materials grown especially to use as a fuel?
a
Which products/materials could be used as fuel for cars?
b
Which products/materials would only be useful to burn in power stations to generate electricity?
c
Explain how you worked out your answers to parts a and b.
4
Which methods could reduce the amount of land used for growing crops for food?
5
Which methods will not add any extra carbon dioxide to the atmosphere at all? Explain your answers.
6
For all the methods you have not listed in your answer to question 5, explain why their use probably will add some carbon dioxide to the atmosphere.
A
Animal dung can be dried and then burned.
F
Animal droppings can be collected and used to make methane gas.
B
Offcuts of wood from furniture making can be burned.
G
Methane gas is given off by some landfill sites.
C
Sugar cane or sugar beet can be used to make ethanol.
H
Oilseed rape can be grown and the oil made into biodiesel.
D
Straw left over after wheat is harvested can be burned.
I
Wheat can be used to make ethanol.
E
Miscanthus (a kind of very tall grass) can be grown and burned.
J
Willow (a kind of tree) can be grown and burned.
Š Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.28c Biofuels Name 1
Class
Date
What is a renewable fuel? Tick one box. a fuel that will run out one day a fuel that does not cause pollution when it burns a fuel that can be replaced, so it won't run out
2
Tick the correct boxes to show if each of these fuels is renewable or non-renewable. Fuel
a b c
petrol
d
wood methane made from animal droppings
e f 3
Renewable
Non-renewable
methane found with crude oil ethanol made from wheat
biodiesel
Why does using biodiesel make our supplies of crude oil last longer? _________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________
4
Jane and Sajid are talking about biodiesel: Jane: “My car uses biodiesel. I'm not putting any extra carbon dioxide into the air because I use biodiesel.”
a
Sajid: “You are adding carbon dioxide, but not as much as if you were using normal diesel.”
Explain why Jane thinks she is not adding carbon dioxide to the atmosphere overall. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
b
Explain why Sajid is correct. ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.28d Biofuel from power plant emissions You do not need to remember the details on this sheet for your exam, but you could be asked to apply your knowledge to unfamiliar situations. The text below is a shortened version of an article by Phil McKenna, published in New Scientist, 6 October 2006. Two of the world's greatest energy users are electricity generation and transport. Both are responsible for huge quantities of greenhouse gas emissions, as most power plants and vehicles still rely on fossil fuels. Now GreenFuel and others are hoping to marry the two together with an emerging technology that uses a by-product of one to supply fuel to the other. Doing so could dramatically reduce their overall carbon dioxide emissions. At the heart of the technology is a plastic cylinder full of algae, which literally sucks the CO2 out of a power plant's exhaust. The algae can in turn be converted into biofuel, creating a cycle that takes the carbon from the smokestack to the gas tank before it enters the atmosphere. If successful, the technology could capture all of a power plant's CO2 emissions. To produce fuel from CO2, the flue gases are fed into a series of transparent ‘bioreactors’, which are 2 metres high and filled with green microalgae suspended in nutrient-rich water. The algae produce sugars, which they then turn into fatty oils. As the algae grow and multiply, portions of the soup are continually withdrawn from each reactor and the oils are extracted. These can then be converted into biodiesel. One key advantage of algae farms over other sources of biofuel such as corn and soybeans is that they need much less space (New Scientist, 23 September, p. 36). In Germany, where rapeseed is the primary crop used for biodiesel, it would take up to 33 times as much land as is needed by the algae bioreactors to produce the same amount of fuel. What's more, unlike other biofuel crops, algae do not require precious commodities like fresh water or fertile land. That makes the technology suitable for use in the deserts of the American south-west and China. 1
a
What is the process in which algae use carbon dioxide?
b
What other reactant is needed for this process to take place?
c
What other substances are needed for the algae to grow?
2
The new system was being developed in the Arizona desert in the USA. Suggest why this proposed method is more likely to work well in this location than it would in the UK.
3
Suggest why the plant needs to be located near to a power station.
4
a
Explain how this process would reduce the amount of carbon dioxide being added to the atmosphere.
b
Why is this a desirable outcome?
5
Explain the advantages of producing biodiesel from algae compared to producing it from rapeseed oil.
6
Is the fuel produced by this process 'carbon neutral'? Explain your answer.
Extra challenge 7
Processes such as the one described in the article are not yet widely used. Suggest some of the problems that engineers may encounter in trying to get the systems to work.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.