Distillation is a separation method aimed to separate
mixtures. The mixture is heated, the element with the lowest boiling point in
the mixture starts to evaporate first and the vapors are condensed by cooling
them to the appropriate temperature. For a two component mixture this would be
the end of the process. If there are more than two components in the mixture
than the process can further be continued by cooling the condensing fluid to
the next lowest boiling point, condensation, and so on.
Crude oil is a mixture that contains hundreds of fractions. The
crude oil is being separated in a refinery by multistep distilation processes. The multistep distilation process allows the wide use of crude oil in: fuels, heating, and materials fabrication.
In the following table there is information regarding a
crude oil batch that arrived to the refinery.
You are the process engineer of the main distillation tower and you have to determine the cooling temperatures for the different condensation fluids of the tower (streams 1, 2, 3), according to the specific crude oil components information given. Please determine the stream temperature according the specific batch information. The tower scheme is presented.
Choose the answer that describes your decision the best:
I like your question. The question is related toeveryday life. The
information you wrote before the question and the video are useful for
understanding and answering the question. The picture you
added to the point on the map, relevant to the subject of the question. I suggest you to add some information about
the picture (point on the map).
The question you created is interesting, require a high cognitive
level of thinking, written with no English mistakes and is related to our everyday
life –production of fuel and other useable materials.
Here is my feedback:
·The point on the map and
the picture are relevant and has a strong connection to the question, but
it should provide additional information that can help the student
answer the question, and it should include an original movie, related to this
extra information, and connects the question to the student’s everyday life.
Your information point doesn’t include all that. My suggestion is to move the
information you wrote about distillation from the question itself to the
information point, add a little bit more information about crude oil distillation
and its products, and create a short movie that shows the oil refineries
·According to the assignment
instructions the question should include a simulation or animation. You included
a movie which is very nice, but in my opinion is too long.
I found the following nice animation/simulation which you might want to use:
·The structure of a
distillation tower is not really clear in your question. Personally I know and understand
the general structure from my previous knowledge, but I think a 7-9th
grade student will find it hard to figure out if not illustrated and explained
in more details. My suggestion is to include a better picture (like the one in
the simulation I suggested or the one here: http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/rocks/fuelsrev3.shtml
for example..) and include it in the information point.
·The question you asked about
the distillation process requires high level of cognitive thinking, maybe even too
high for young students. Consider asking a different question.
I added a point on the map which
talks about a very basic and natural distillation process in nature – the evaporation
of the sea saline water and the creation of rain drops which are actually distilled
History of edits
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