Crude oil
Teachers’ notes and lesson plans
2 – 3 lessons
TO BE ADDED
Click here to launch the
Crude oil challenge
Crude oil Introduction
Introduction
You can deliver this activity in three lessons as below, or simplify the ideas to deliver
in a shorter time.
Crude oils are made of different mixtures of hydrocarbons that are unique to the conditions
under which each reservoir formed over millions of years. For this reason every crude oil is
different. The economic value in crude oil is realised when these constituent hydrocarbons
are separated into groups with similar properties, which can be processed into products
demanded by consumers or industry. In this interactive challenge, students must separate
a sample of crude oil into its four main fractions, to understand how much of each fraction
makes up the oil – and therefore how valuable it may be. They must then use this information
to suggest the best place for the crude oil to be sent for refining and processing, based on
demand for the fractions they discover.
Topic relevance
•Fossil fuels
•Physical changes
•Mixtures and compounds
•Separating mixtures
Learning outcomes and assessment opportunities
Your actual learning outcomes will vary depending on your approach and how you include discussion
of topic-related concepts.
At the end of this challenge:
All students should be able to:
Most students will be able to:
Some students will be able to:
•identify the dependent,
independent and control
variables
•explain in simple terms what
happens as a liquid boils
•list the changes that occur
when water is distilled
•describe crude oil as a mixture
of molecules of different sizes
•note that crude oil can be
separated using distillation.
•outline fractional distillation as
a way to separate a liquid mixture
•explain in simple terms that
lighter fractions rise higher up
the column
•describe the proportions of each
fraction in their crude oil sample
•link the sample to the best
location
•note that crude oil is separated
using fractional distillation,
where molecules with different
boiling points leave the oil at
different temperatures.
•explain fractional distillation
in terms of the different boiling
points of each fraction
•make a simple qualitative
prediction for the proportions
of the main fractions in a
lighter or heavier crude oil
than their test sample.
Prior learning/skills
It is helpful, although not necessary, if students know that:
•solids, liquids and gases
•mixtures v compounds
•physical v chemical changes
•fossil fuels
2
Crude oil Background
Background
The data in this interactive is based on a real analysis of one of BP’s oil fields. The data ignores a small
fraction of the oil (under 1% in this case) that is gaseous at normal temperature and pressure, containing
C1–C4 hydrocarbon chains. The four fractions are those used in industry-standard crude oil assays.
While each fraction contains a range of molecules, the distribution of boiling points within a fraction
is not even, and the boiling point ranges for each fraction also differ.
For simplicity, the interactive makes an assumption that the effect of setting the temperature incorrectly
has a linear effect on what is distilled (e.g. boiling points are evenly distributed across the range of
molecules that makes up each fraction), and introduces a set portion of the fraction above or below for
every degree of error. If students set the temperature too high, some of the next heaviest fraction will
be included in their collecting vessel; if they set it too low, not all the fraction will be distilled and will be
added to the next fraction.
Again for simplicity, the interactive makes no distinction between heat energy that is used to increase
the temperature of the remaining mixture, and the latent heat absorbed by the evaporating fraction.
None of this requires clarification with students unless you wish to explore these ideas with more
able students.
BP and crude oil
Crude oil production facilities
After BP has established that there are large enough quantities of oil or gas (or both) at a drilling location
to be commercially viable, this site is known as a field. The next step is to plan and build a production
facility, taking technical, environmental, social and logistical factors into account.
Out at sea, BP builds oil or gas platforms which are strong and steady enough to cope with the amounts
of oil and gas to be extracted, the depth of the water and the harshness of the climate and underwater
environment.
Over the decades-long lifespan of most production facilities, chances are new technologies will help BP
to extract greater proportions of the resources within the rocks which hold the hydrocarbons.
Most of the world’s known oil and natural gas supplies are a long way away from the places where these
resources are the most in demand. Even land-based production facilities may be many kilometres from the
closest refinery or distribution terminal.
Transporting crude oil
BP transports crude oil in two main ways: pipelines and shipping. The choice depends on each project’s
logistics, economics and location, as well as environmental considerations. Meanwhile, arranging to get
large amounts of oil, gas and energy products to all the places where they are needed is a steady and
demanding job in itself.
3
Crude oil Background
Using crude oil
BP has interests in 16 refineries around the world. With chemistry know-how, special equipment and a
number of patented technologies, the thousands of people who work in its refineries take in a steady flow
of crude oil, turning it out again in the form of products that most people couldn’t do without.
The vast majority of the crude oil that goes through a BP refinery leaves it as gasoline or diesel. But the
range of products BP produces is much wider than automotive fuels. In fact, these products touch almost
every aspect of modern life.
For instance,BP’s petrochemical production focuses on two specific but versatile types of chemicals: acetyls
and aromatics. Acetyls are the building blocks of many consumer products, from adhesives to cosmetics.
Aromatics include a material found in one in three polyester shirts.
Preparation
Before delivering these lessons, you may wish to:
•review BP’s refinery activities using the web links page and the link in lesson 1 below
•try the interactive for yourself
•print copies of the Crude oil information sheet, the Planning sheet and the
Skills evaluation sheet PDFs, all needed by your students
•book ICT facilities if required for small group work
•identify which science skills you may wish to focus on during these lessons – see table below the
lesson plans
•consider the follow-up activities below, including a practical session and communication task.
Students will need:
•Paper for presenting their data as a pie chart
You may want additional resources for exploring the basics of crude oil and distillation in lesson 1.
These may include a simple set-up to distil water using a round-bottomed flask and leibig condenser,
and the Oil Products set available from BPES.
Note that suggested timings are necessarily approximate and may not allow you
to explore every discussion point that is included below.
4
Crude oil Lesson 1
Lesson 1
Starter (each challenge follows the same structure for the starter activity).
Activity
Time
•How do scientists use their skills to solve real-world problems?
What sort of scientific questions might they have to ask and answer?
Gather students’ ideas – you may want to seed them with familiar products or areas
of life to consider.
5 mins
Explain that for the next few lessons, students will take on the role of teams of BP
scientists. They are going to be given a real-world problem which they must help
a colleague with, and they will ask and answer a scientific question.
The worlds of business and science can have different priorities.
As appropriate, discuss the idea of scientists and non-scientists
working together:
•What might scientists need to understand and remember about the needs of their
non-scientist colleagues? (Language, the need for a fast answer, non-scientific issues
that may also affect the outcome, etc.)
•What might a non-scientist need to bear in mind when asking for assistance?
(The need to frame the question in a scientific way, the need for an answer to be
reliable and accurate, the limits to conclusions that can be drawn from the data etc.)
5 mins
Main
Activity
Introduce the topic of crude oil and how it is turned into useful products, and gather
students’ current knowledge and understanding, for example, by creating concept maps
in small groups or as a whole class.
Time
5 mins
Briefly review what students already know, which may include the concepts of fossil fuels,
refining, products made from oil and climate change. You may wish to extend students’
thinking to include things that are making better use of crude oil: improvements in car engine
efficiency, recycling of plastics made from crude oil and new ways to reach oil that was
previously too difficult to extract.
Enter the Crude oil challenge, noting the introduction text.
5 mins
Watch the Briefing video. This contains a number of facts that students
require to plan their investigation – can they spot them? Discussion points:
•Each reservoir of crude oil formed from a different mixture of decomposing marine
micro-organisms, in a unique location that was then subject to unique temperatures
and pressures over millions of years. You could make a simple comparison to the idea
of a recipe for vegetable soup: you might start with similar ingredients, but by using
different amounts and cooking for different amounts of time, you can end up with lots
of variations: thick, thin, one with lots of carrot, one with lots of onion, etc.
5
Crude oil Lesson 1
•Crude oil isn’t worth much by itself because the mix-up of molecules isn’t useful.
You could use the analogy of a large pile of coins from different countries. Mixed up,
the coins aren’t useful, but when separated into coins from each country, each pile of
coins now becomes useful. If the mixture contains more coins from the United States,
it makes sense to sort the coins there, since that’s where most of the mixture of coins
will end up being useful.
Before considering the challenge, introduce or review the idea of distillation
with your students:
10–15
mins
Show them a simple set-up at work, using a Bunsen burner, round-bottomed flask and
Leibig condenser. Depending on your group, you may want to include a thermometer to
indicate the temperature of the water before and during boiling. Discussion points:
•What is the burner doing? (Giving heat energy to the water in the flask.)
•What does this heat energy do? (Increases the temperature of the water until it reaches
boiling point.)
•Where does the heat energy go once the water is boiling? (Gives the water molecules
enough energy to ‘escape’ as water vapour.)
•What happens in the condenser? (The cold water cools the vapour, which condenses
again into liquid water in the collection vessel.)
How does this process help to separate a mixture? You may first wish to briefly consider
an alcohol/water mix in your set-up. What will happen as the mixture is heated? Link to the
drinks distilling industry.
Click to open this link to BP’s website in another browser window and explore the online
animation of fractional distillation (scroll below the animation to read a brief explanation).
5–10
mins
Use the online animation to consider the mixture of molecules in crude oil. With different
boiling points, this means that some molecules will evaporate and condense at different
temperatures from others.
•The bottom of the column is hot enough to make nearly all the molecules evaporate,
leaving just the very heaviest molecules.
•Each level of the column is kept at a different temperature, hotter at the bottom and
cooler towards the top.
•At each level, some molecules will condense and are drawn off as a liquid. This will
happen if the temperature at that point is lower than their boiling point.
•The other molecules remain as a vapour. These molecules pass up the column through
the ‘bubble caps’ in each level, until they reach a level that is cool enough for them
to condense.
•In this way, different molecules condense at different levels. The fractionating column
has separated the mixture in the crude oil.
6
Crude oil Lesson 1
Plenary
Activity
Review the Crude oil information sheet from your BP colleague.
Discussion points:
•Briefly discuss the products that are made from each fraction. Which ones do
students think are most useful? (E.g. naphtha, kerosene.)
•Why might the kerosene be most important for this crude oil? (Perhaps there is
rising demand for jet fuel.)
•Imagine that students have set the temperature of their distillation equipment to
remove the kerosene (232˚C). Discuss how the volume indicator in the collecting
vessel will help them to know when all the kerosene has evaporated and condensed.
•What might happen if they set the temperature too low (not all the kerosene fraction
might evaporate) or too high (some of the gas oil fraction might also evaporate)?
What effect could this have on their analysis? (They will not get an accurate
measurement for the amount of kerosene and so could match the crude oil to the
wrong place.)
Time
10 mins
Review students’ understanding using the Check your facts quiz. Using
the feedback, discuss briefly how each important fact is necessary for an
investigation of the amount of each fraction in the oil.
Explain that in the next lesson they will use their science skills to separate some crude
oil in the interactive, using what they have learnt.
Differentiation
Easier: Use a ‘people’ analogy to consider how molecules boil: get less able students to think of
themselves as moving on the spot (vibrating) like a molecule. If they don’t move too much, they are
able to loosely hold onto each other (like the bonds holding a liquid together). But if they are heated
up, the heat energy makes them vibrate more strongly. This makes it harder for them to hold onto
each other. Eventually they vibrate so much that they must let go and ‘escape’: they have become
a vapour. Lighter people vibrate enough to let go more quickly than heavier people, who need more
energy to make them move.
Harder: Challenge more able students to explain for themselves how the fractionating column works and
why longer molecules may have higher boiling points (they need more energy to ‘escape’). Get them to
think of other properties that indicate that heavier fractions have longer molecules and lighter ones have
smaller molecules (viscosity, flammability).
7
Crude oil Lesson 2
Lesson 2
Starter
Activity
Time
Recap and focus students:
•Who is their BP colleague?
•What scientific question are they going to ask?
•How will this help their colleague?
5 mins
Watch the Briefing video again if necessary, and review students’ Planning and
Skills evaluation sheets. Remind them that they are going to complete an interactive
investigation during the lesson, taking on the role of a BP science team.
Main
Activity
Time
What must students do in their investigation, and what science skills will they use?
Review the Planning sheet and Skills evaluation sheet as a class, using the information
you have been given to help you, and the skill ideas below these lesson plans.
Complete the first writing frames on the Planning sheet. If working as a whole class,
students can complete as individuals or in pairs. If working in small groups, students
can complete in their groups.
10 mins
Using a focus suitable for your class or individual students, review the ideas on the
Skills evaluation sheet, thinking about students’ plans and how they will work together
to complete their investigation. Ideas are below the lesson plans.
Are we ready for our investigation?
Review students’ ideas:
•Their scientific question could be ‘How much of each fraction does the new oil
contain?’
•Variables are temperature (independent), collector volume (dependent) and sample
volume (control – set to 1000ml each time).
•Students should consider repeating their test three times to get average readings
– why is this helpful?
•Students should recognise that they are not able to make a prediction in this
investigation (see below for ideas on discussing this with more able students).
8
Crude oil Lesson 2
Optionally, watch the Planning video as part of your review. Remind students that
they will need their Planning and Skills evaluation sheets during the next lesson.
Enter the Main interactive. Using students’ Planning sheets to remind them,
review the information on the opening screen as a whole class.
25 mins
•Note that the instructions tab in the activity screen provides hints and tips for students.
•Students should move between the activity and data recorder screens as they
change their independent variable, and record their measurements.
Working as a whole class or in small groups, students use the activity screen to gather
data for their investigation, remembering to set the temperature carefully each time and
watch to be sure that all of each fraction has collected.
Students click on the finish button when they have gathered the data they think they
need, and print out their results.
Plenary
Activity
Time
How accurately have they set the temperatures? Discuss students’ initial results and
the reasons for any variance in the class. Link students’ results to the idea of extra
molecules being able to escape, or not all molecules being able to escape.
5 mins
Explain that crude oil analyses must be carried out extremely carefully, so they will
repeat their test twice at the start of the next lesson, to obtain average results.
•Why is the analysis so important? (Linked to the value of the crude, which may have
a volume of millions of barrels and require significant investment to extract, so it’s
vital to know exactly what it’s potentially worth, so the right decisions can be made.)
Differentiation
Easier: Highlight the temperatures that students must set – the top one for each fraction’s range.
Remind students to pause their heating as soon as the temperature reaches the top temperature for
each fraction – one person should watch this all the time. Remind them to change containers after
collecting and measuring each fraction.
Harder: Discuss the idea that they can’t make a prediction here. But what if they knew qualitatively how
this oil compares to another? If their ‘test’ crude is light and thin, what balance of fractions would they
predict they would find compared to a dark, thicker crude? Tease out their idea to help them understand
that heavier fractions contain longer molecules.
9
Crude oil Lesson 3
Lesson 3
Starter
Activity
Time
Recap and focus students:
•What they learned and achieved in lesson 2 during their first test.
•How they might improve their work as they repeat their test two more times.
5 mins
Main
Activity
Time
Enter the Main interactive.
Working as a whole class or in small groups, students use the activity screen to gather
data two more times, remembering to set the temperature carefully each time and
watch to be sure that all of each fraction has collected.
25 mins
Students click on the finish button when they have gathered the data they think they
need, and print out their results.
Using paper, students create a pie chart to show their results (or discuss what form,
chart or graph is most appropriate, since their results show parts of a whole).
10 mins
•Why is a pie chart appropriate for this data?
•What is the largest fraction?
•What proportion of the crude oil is made up of kerosene?
Proceed to the Decision time quiz and use students’ charts to answer the two
questions from their BP colleague.
•Correct answers are that the crude contains 12% kerosene and that it should
therefore go to [insert name] for processing, as this refinery is set up for this type
of oil, to serve the local market where demand is similar.
10
Crude oil Lesson 3
Plenary
Activity
Time
How did our science skills help us?
Depending on the skills on which you chose to focus, use students’ Skills evaluation
sheets to review how they have used each skill (see below for ideas).
10 mins
•Discuss how the class has used a simple investigation to solve a real-world problem,
and what they have learned about one way of separating a mixture.
Watch the Round-up video for ideas if you have not done so already.
Differentiation
Easier: Highlight to less able students that they need to match their pie chart to the one that looks
most similar, remembering which fraction is which. Provide them with additional data so that they
don’t need to repeat their test twice. Discuss with them any anomalous results, where one out of
three results for a fraction appears very different. Should they use this or get another result? What
might have happened?
Harder: Challenge more able students to explain why it makes commercial sense to transport the crude
oil to a refinery that already deals with a similar oil (its mixture of processes will be better adapted to make
the most of that mixture of fractions, avoiding the need to invest in more equipment at a different refinery).
What fractions do they think are high in demand all over the world? (E.g. gasoline – petrol.) Why are some
less valuable? (E.g. heavy fuel oil, for which there is more limited use.)
Follow-up tasks
Follow-up communication tasks
As a follow-up lesson and/or homework task, students could:
•create a step-by-step explanation, using a poster, web page or Flash animation, to explain distillation
in terms of energy, states of matter and changes
•create a presentation to explain why some crude oils may be more economically valuable than others,
in terms of the different mixtures of molecules that they contain
•pretend that they are leading a tour of a BP refinery and create an explanation, in their own words,
of fractional distillation, which they could record as a video or as an audio track for visitors to listen to.
11
Crude oil Skills and safety
Skills and safety
Developing science skills
Planning and
predicting
•Students should be able to plan how they will vary the temperature,
for example, listing the temperature settings at which they will pause while
each fraction collects.
•They could predict what will happen if each temperature is too low or too high.
•Some can predict how the proportions of the fractions might vary between
thicker and thinner oils.
Working with
variables
•The sample size can be treated as a control variable, although more able
students will note that the proportion of each fraction will be the same in
percentage terms.
•Temperature is the independent variable.
•Collector output is the dependent variable and can have any value
it is continuous).
Obtaining and
presenting
evidence
•Discuss why a pie chart is appropriate. How does it allow us to easily compare
this crude against other oils?
•What other information could be shown using a pie chart? (Think of anything
that involves parts of a whole, such as the proportion of people with hair of
different colour, those who can/cannot roll their tongue etc.
Analysing and
evaluating
evidence
•How reliable is the evidence? Consider taking samples from different parts of
the reservoir, so that BP know that the crude oil has the same composition in
all parts (the volume of porous rock that makes up a reservoir can be massive;
the oil quality will vary and the oil/gas ratio will vary).
Collaborating
Students could:
•discuss their ideas and agree what their results will and won’t show them,
and whether or not they are testing a prediction in this test
•share the work of changing variables and taking measurements
•work together to transfer their results to a line graph
•discuss their evidence and agree what it does and does not tell them.
Communicating
•use scientific language (e.g. temperature, heat, volume, physical change,
gas, liquid, evaporate, condense, proportion). (See also follow-up
communication ideas above.)
Reflecting
•Reflect honestly on their performance.
•Invite feedback from their group members.
•Set goals for developing their skills.
•See the relevance of what they have learned.
12
Crude oil Skills and safety
Safety
As part of your exploration of the science skills that students will use, you may
wish to discuss with the class the safety precautions they would take if this were
a real investigation:
What hazards
are there?
•Hot equipment and distillates.
•Crude oil contains a carcinogen (benzene).
What
precautions
could students
take?
•Measure oil sample in a sealed fume cupboard.
•Ensure ventilation.
•Collect distillates in a sealed container.
•Wear eye protection and protective clothing.
What
information
could they use?
•Hazcards.
•Hazard warning signs for chemicals and hot equipment.
13