This course is designed to introduce students to the issues of energy in the 21st century – including food and fuels – which are inseparably linked – and will discuss energy production and utilization from the biology, engineering, economics, climate science, and social science perspectives. This course will cover the current production and utilization of energy, as well as the consequences of this use, examining finite fossil energy reserves, how food and energy are linked, impacts on the environment and climate, and the social and economic impacts of our present energy and food production and use. After the introductory lectures, we will examine the emerging field of sustainable energy, fuel and food production, emphasizing the importance of developing energy efficient and sustainable methods of production, and how these new technologies can contribute to replacing the diminishing supplies of fossil fuels, and reduce the consequences of carbon dioxide release into the environment. This course will also cover the importance of creating a sustainable energy future for all societies including those of the developing world. Lectures will be prepared and delivered by leading UC San Diego and Scripps Institution of Oceanography faculty and industry professionals across these areas of expertise.
Petroleum Part 2
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Del curso dictado por University of California San Diego
Our Energy Future
434 calificaciones
De la lección
Introduction to Energy
Introduces the basics of energy, covers finite energy sources like petroleum, looks at how energy and food are related, and examines the scale of current and future energy consumption and what renewable energy options can meet that demand.
Conoce a los instructores
Dr. Stephen MayfieldProfessor of Molecular Biology
University of California San Diego
[MUSIC]
Skip thanks very much for the talk I, I hope we know
a little bit more about petroleum now and where it comes from.
I noticed that on one your slides when,
when you were listing all the, the, the different
densities, I, I think of it that at the very bottom were tar sands, or tar, right?
And I know, and, and, and some of our viewers will know
that tar sands were actually the
number one hydrocarbon imported into this country.
Why are importing tar, you know, into this, into this country?
What do we do with it?
>> Well, we do with it what we're doing
with the oil, we're trying to create more gasoline.
And so, in order to bring that into the country, we're taking those tar
sands and we're chemically reacting them so that we can get them into a pipeline.
And then we're just transferring them to a refinery.
And then we're taking those really heavy long chains in the tar sands, and we're
just breaking them down through a lot of cracking, until we get back to gasoline.
>> Okay, so in the end we're just one hydrocarbon broken down
into smaller carbons that, that we, we eventually put in our cars.
Okay, so I, I also know that in the, you know, the very first
stage, the, sort of the first cars that were run, they were run on ethanol.
>> Mm-hm.
>> Some on peanut oil, but, but, but ethanol was
a fuel, and then very quickly, that changed over to gasoline.
You know, I, I, I think, you know, why, you know, what happened
that made gasoline so popular, and why did we, we get rid of ethanol?
Well, when John Rockafella was refining petroleum from kerosene for lamps,
he realized electricity was on the forefront, and he also needed a
new industry, gasoline was a fraction, he was literally throwing away, so
he convinced Henry Ford to redesign the engines to burn the gasoline.
That actually, through manufacturing, the gasoline was
cheaper than the ethanol was at the time.
And in addition, gas has a couple really important nice properties.
Water doesn't mix with it, so you don't have
to worry about getting water in your gas tank.
And the other thing is it's stable and, and free of microbial degradation.
Unless, you've got really aggressive conditions, so it will stay still
for a long period of time, and not foul up your engine.
>> So chemically, it was a better fuel?
>> [CROSSTALK].
>> And then, and then because we're mining
it, it was actually cheaper to make [INAUDIBLE].
>> Than ethanol.
>> Than ethanol, okay.
So for those two reasons.
We, we here a lot you know, about bio crude.
And, and I, and I see reports now that we
can get crude oils that are made from biological sources.
You know, al, algae and [UNKNOWN], two that, that we've mentioned here.
So, how is crude oil, or biological oils different from petroleum?
>> Really not very much, I mean, you're taking the same, you're
taking biomass, and you're basically heating it in an absence of oxygen.
So, that that was very much just like
we did with the petroleum that was formed from
the biomass that got to the bottom, was
covered by sediments, no oxygen, increasing heat and pressure.
We basically now do the same thing artificially.
There are small differences in that there's going to be some more oxygen and
nitrogen in those, those compounds, but by
and large, they're pretty much the same molecules.
And so those things can go right to the refineries as well.
>> So the refineries that we have can take either crude oil, or
they could take bio crude and, and in either case, put out gasoline.
>> Absolutely.
>> Okay, so, so, along those lines then, in,
in, in this country we primarily have gasoline engines.
In Europe it's much more common to have diesel.
Diesel's becoming, you know, more popular here.
So I guess the question is, chemically, what's the difference between the two?
Can I, you know, obviously I can't swap diesel for
gasoline in my existing engine but maybe overall, we could.
Well, all the difference is, is the length of the hydrocarbon chain.
So diesels are diesel fuel is a longer hydrocarbon chain.
And as a result, it has a higher flash point.
Now in a diesel engine, which is a high compression engine, then you get
the auto combustion at the real high
temperatures and pressions, pressures inside that diesel engine.
Diesel engines are really the thermally best of
engine that you have operating a high compression.
So, in Europe, they use subsidies to make sure that the diesel is
at lower price so that's why they have more of it over there.
But in essence, they're really the same thing, just different chain length.
Different, and then as a result, then different engines.
>> So, so, chemically, slightly different, and therefore have different
engines, but really, more or less doing the same thing.
>> Absolutely.
>> Liquid, put em in.
>> Absolutely.
>> Turn, turn that liquid fuel into energy.
>> That, that thing we refer to as fit for purpose fuel, right?
So that it's safe to use, got a good range, good energy density.
Doesn't blow up.
>> Yeah.
One of the other things I noticed in your talk is that you, you,
you had the map of the world showing where the different oils come from.
You know, why is it that, for example, in West Texas or Brant, we have light, sweet
oils, and then in Russia, we have, you know, more heavy, sour oils.
What, what's the difference in geography there that
makes the fuels, the, the crude oil, different?
>> It has to do with what sort of biomass was used and laid down into the
rock formations, but it also has a lot to do with how long it's been in the ground.
The longer it's been in the ground, the heavier the oils tend
to get, and so the, the, the lighter ones are probably younger ones.
>> Okay.
And then obviously the heavier they get, the
harder they are to get out of the ground.
>> Harder.
Therefore more expensive.
So we're.
>> Well, they're actually, have less value on the market.
>> As well.
>> And so you pay less for them, but that's because you have
to make up for the cost you're going to have to use in refining.
>> Okay.
>> So, so the, the most expensive raw material would be the Brent
sweet crude, because it will yield you the most bang for the buck.
>> Right.
>> The other ones that are going, you buy them at a lower price.
Okay, I, I, so I understand that.
And then, I guess also, you know, what, what one
of the things that we'd like to think about is, you
know, in the future, how are we going to get renewable
fuels to replace the fossil fuels that we're running out of.
So what do you see, I think, from, from a
chemistry point of view, maybe, or from your point of view,
what's the important things that we're going to need to work on
so that we can get renewable biofuels to replace fossil fuel?
>> Biofuels have two issues, and one is that you have to, in
many cases, you have to clear land, which is a loss in carbon as
you burn and clear that land, and then the other part is there's
the energy and use in the process
of turning Those materials into workable fuels.
And so, the other thing is they're, all those
operations are very water-intensive, which is a previous resource.
In some cases, they're food commodities, and so,
I think we need to find ways where we're
not affecting the price of food and we're not
using substantial amounts of water or good, arable land.
And then burning crops in order to clear that land.
The last part I think was the research has to be and
how do we recover and recycle the key nutrients like phosphorous and nitrogen.
If we don't really find a way to do that, we can't have sustainable
renewable fuels because we, you know, we're
just going to be taking petroleum, one limited resource.
And substituting it for another one phosphorous.
>> But, but in the case of fuels which are only hydrogen and carbon obviously,
we have the opportunity to recycle hydrogen
and phosphate molecules because they're not consumed fuel.
>> They're not consumed fuel.
>> All right, well thanks very much for the
talk and best of luck on your research here.
>> All right, thank you very much.
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